2014 v9n2

IJSPT

INTERNATIONAL JOURNAL OF SPORTS PHYSICAL THERAPY

VOLUME NINE issue two april 2014

IJSPT

INTERNATIONAL JOURNAL OF SPORTS PHYSICAL THERAPY

Editor in Chief Michael L. Voight, PT, DHSc, OCS, SCS, ATC, CSCS Belmont University Nashville, Tennessee – USA

Associate Editors, Thematic Issues: Robert Manske, PT, DPT, Med, SCS, ATC, CSCS Wichita State University Wichita, Kansas – USA

Senior Associate Editor Barbara Hoogenboom, PT, EdD, SCS, ATC Grand Valley State University Grand Rapids, Michigan - USA

Associate Editors: Mario Bizzini, PT, MSc Schulthess Clinic Zürich – Switzerland

Manuscript Coordinator Ashley Campbell

Henning Langberg, PT, PhD, MSc Institute of Sports Medicine Copenhagen – Denmark

Managing Editor Mary Wilkinson

Editorial Board: Scott Anderson, PT, Dip Sport PT Northgate Physical Therapy Regina, Saskatchewan – Canada

John A. Guido, Jr., PT, MHS, SCS, ATC, CSCS Ochsner Health Systems New Orleans, Louisiana – USA

Lindsay Becker, PT, DPT, SCS, CSCS The Ohio State University Sportsmedicine Center Columbus, Ohio – USA

Elizabeth L. Harrison, PT, PhD, Dip Sport PT University of Saskatchewan Saskatoon, Saskatchewan – Canada

Barton Bishop, PT, DPT, SCS, CSCS Sport and Spine Rehab of Rockville Rockville, Maryland – USA

Walter L. Jenkins, PT, DHS, ATC East Carolina University Greenville, North Carolina - USA

Turner A. “TAB” Blackburn, Jr., MEd, PT, ATC Clemson Sports Medicine and Rehabilitation Manchester, Georgia – USA

Daniel S. Lorenz, PT, DPT, ATC, CSCS Providence Medical Center Kansas City, Kansas - USA

Rick Clark, PT, DScPT, CCCE Air Force Academy Colorado Springs, CO – USA

Lorrie Maffey, PT, MPT, Dip Manip PT University of Calgary Calgary, Alberta – Canada

George J. Davies, PT, DPT, SCS, ATC, FAPTA Armstrong Atlantic State University Savannah, Georgia – USA

Terry Malone, PT, EdD, ATC, FAPTA University of Kentucky Lexington, Kentucky – USA

Mark S. De Carlo, PT, DPT, MHA, SCS, ATC Accelerated Rehabilitation Indianapolis, Indiana – USA

Peter J. McNair, PT, PhD Auckland University of Technology Auckland – New Zealand

Todd S. Ellenbecker, DPT, SCS, OCS Physiotherapy Associates Scottsdale Sports Clinic Scottsdale, Arizona – USA

Grethe Myklebust, PT, PhD Oslo Sport Trauma Research Center Norwegian School of Sports Sciences Oslo – Norway

EDITORIAL STAFF & BOARD

Phil Page, PT, PhD, ATC, CSCS The Hygenic Corporation Akron, Ohio – USA

Kevin Wilk, PT, DPT Champion Sports Medicine Birmingham, Alabama – USA

Mark Paterno, PT, PhD, MBA, SCS, ATC Cincinnati Children’s Hospital Medical Center Cincinnati, Ohio – USA

Erik Witvrouw, PT, PhD Ghent University Ghent – Belgium

Michael P. Reiman, PT, DPT, OCS, SCS, ATC, FAAOMPT, CSCS Duke University School of Medicine Durham, North Carolina – USA Mark F. Reinking, PT, PhD, SCS, ATC Saint Louis University St. Louis, Missouri – USA Jill Robertson, PT, MSc (PT), Dip Manip PT Beaverbank Orthopaedic and Sport Physiotherapy Halifax, Nova Scotia – Canada Kevin Robinson, PT, DSc, OCS Belmont University Nashville, Tennessee – USA Barbara Sanders, PT, PhD, SCS, FAPTA Texas State University-San Marcos San Marcos, Texas – USA Teresa L. Schuemann, PT, DPT, SCS, ATC, CSCS Colorado Physical Therapy Specialists Fort Collins, Colorado – USA Patrick Sells, DA, ES Belmont University Nashville, Tennessee – USA Laurie Stickler, MSPT, OCS Grand Valley State University Grand Rapids, Michigan – USA Steven R. Tippett, PT, PhD, SCS, ATC Bradley University Peoria, Illinois – USA Timothy F. Tyler, PT, ATC NISMAT Lenox Hill Hospital New York, New York – USA Timothy Uhl, PT, PhD, ATC University of Kentucky Lexington, Kentucky – USA Mark D. Weber, PT, PhD, SCS, ATC University of Mississippi Medical Center Jackson, Mississippi – USA

international JOURNAL OF

IJSPT

SPORTS PHYSICAL THERAPY

I N T E R N AT I O N A L J O U R N A L OF SPORTS PHYSICAL THERAPY

SPORTS PHYSICAL THERAPY SECTION

Editorial Staff

Executive Committee

Michael L. Voight, PT, DHSc, OCS, SCS, ATC Editor-in-Chief

Tim Tyler, PT, MS, ATC

Barbara Hoogenboom, PT, EdD, SCS, ATC Grand Valley State University Grand Rapids, Michigan - USA Senior Associate Editor

Robert Manske, PT, DPT, Med, SCS, ATC, CSCS Vice President

Robert Manske, PT, DPT, Med, SCS, ATC, CSCS Wichita State University Wichita, Kansas – USA Associate Editor, Thematic Issues Associate Editors Mario Bizzini, PT, MSc Schulthess Clinic Zürich – Switzerland

President

Teresa L. Schuemann, PT, DPT, SCS, ATC, CSCS Secretary Bryan Heiderscheit, PT, PhD Treasurer Stacey J. Pagorek, PT, DPT, SCS, ATC Representative-At-Large

Administration Mark S. De Carlo, PT, DPT, MHA, SCS, ATC Executive Director Tammy Jackson Executive Assistant

Henning Langberg, PT, PhD, MSc Institute of Sports Medicine Copenhagen – Denmark

Mary Wilkinson Director of Marketing Webmaster Managing Editor, Publications

Ashley Campbell Manuscript Coordinator Mary Wilkinson Managing Editor

Contact Information

Advertising Sales The International Journal of Sports Physical Therapy accepts advertising on its website, www.ijspt.org.

9002 N. Meridian Street, Suite 112A Indianapolis, Indiana 46260 877.732.5009 Toll Free • 317.829.5790 Voice 317.829.5791 Fax www.spts.org

Log on to http://www.ijspt.org/advertisers for more information about rates and placement opportunities.

You may also email Mary Wilkinson, Marketing Director, at mwilkinson@spts.org or contact by phone at 317.501.0805.

I N T E R N AT I O N A L J O U R N A L OF SPORTS PHYSICAL THERAPY is a publication of the Sports Physical Therapy Section of the American Physical Therapy Association.

IJSPT is also an official journal of the International Federation of Sports Physical Therapy (IFSPT).

IFSPT

IJSPT is a bimonthly publication, with release dates in February, April, June, August, October and December.

ISSN 2159-2896

TABLE OF CONTENTS VOLUME 9, NUMBER 2

Page Number Article Title Original Research 135 Validation of measures from the smartphone sway balance application: a pilot study.

Authors: Patterson JA, Amick RZ, Thummar T, Rogers ME 140

Feasibility and reliability of dynamic postural control measures in children in first through fifth grades.

Authors: Faigenbaum AD, Myer GD, Fernandez IP, Carrasco EG, Bates N, Farrell A, Ratamess NA, Kang J

149

Effect of injury prevention training on knee mechanics in female adolescents during puberty.

Authors: Otsuki R, Kuramochi R, Fukubayashi T

157

Effects of hip strengthening on early outcomes following anterior cruciate ligament reconstruction.

Authors: Garrison C, Bothwell J, Cohen K, Conway J

168

Associations between knee extensor power and functional performance in patients after total knee arthroplasty and normal controls without knee pain.

Authors: Marmon AR, Milcarek BI, Snyder-Mackler, L

179

A criterion-based sling weaning progression (SWEAP) and outcomes following shoulder arthroscopic surgery in an active duty military population.

Authors: Hire JM, Pniewski JE, Dickston ML , Jacobs, JM, Mueller TL, Abell BE, and Bojescul JA

187

Intra-rater and inter-rater reliability of the five image-based criteria of the foot posture Index-6.

Authors: Terada M, Wittwer AM, Gribble PA

195

Intra- and inter-rater reliability of the Selective Functional Movement Assessment (SFMA) Authors: Glaws KR, Juneau CM, Becker LC, Di Stasi SL, Hewett TE

Case Report 208

Rehabilitation of a 23-year-old male after right knee arthroscopy and open reconstruction of the medial patellofemoral ligament with a tibialis anterior allograft: a case report.

Author: Cheatham S, Kolber MJ, Hanney WJ

222

Treatment of distal iliotibial band syndrome in a long distance runner with gait re-training emphasizing step rate manipulation Author: Allen DJ

232

Rehabilitation strategies addressing neurocognitive and balance deficits following a concussion in a female snowboard athlete: a case report Author: Faltus J

Clinical Commentary 242 Pediatric sports-specific return to play guidelines following concussion Authors: May KH, Marshall DL, Burns TG, Popoli DM, Polikandriotis JA 256

Radiological examination of the hip: clinical indications, methods, and interpretation: a clinical commentary.

Authors: Reis AC, Rabelo NDA, Pereira RP, Polesello G, Martin RL, Lucareli PRG, Fukuda TY

268

ACL reconstruction: it’s all about timing.

Authors: Evans S, Shaginaw J, Bartolozzi A

274

Current concepts of rotator cuff tendinopathy.

Authors: Factor D, Dale B

IJSPT

ORIGINAL RESEARCH

VALIDATION OF MEASURES FROM THE SMARTPHONE SWAY BALANCE APPLICATION: A PILOT STUDY Jeremy, A. Patterson, PhD, FACSM1 Ryan Z. Amick, MEd2 Tarunkumar Thummar, PT, MEd1 Michael E. Rogers, PhD, FACSM1

ABSTRACT Purpose/Background: A number of different balance assessment techniques are currently available and widely used. These include both subjective and objective assessments. The ability to provide quantitative measures of balance and posture is the benefit of objective tools, however these instruments are not generally utilized outside of research laboratory settings due to cost, complexity of operation, size, duration of assessment, and general practicality. The purpose of this pilot study was to assess the value and validity of using software developed to access the iPod and iPhone accelerometers output and translate that to the measurement of human balance.

Methods: Thirty healthy college-aged individuals (13 male, 17 female; age = 26.1 ± 8.5 years) volunteered.

Participants performed a static Athlete’s Single Leg Test protocol for 10 sec, on a Biodex Balance System SD while concurrently utilizing a mobile device with balance software. Anterior/posterior stability was recorded using both devices, described as the displacement in degrees from level, and was termed the “balance score.”

Results: There were no significant differences between the two reported balance scores (p = 0.818. Mean balance score on the balance platform was 1.41 ± 0.90, as compared to 1.38 ± 0.72 using the mobile device.

Conclusions: There is a need for a valid, convenient, and cost-effective tool to objectively measure balance.

Results of this study are promising, as balance score derived from the Smartphone accelerometers were consistent with balance scores obtained from a previously validated balance system. However, further investigation is necessary as this version of the mobile software only assessed balance in the anterior/posterior direction. Additionally, further testing is necessary on a healthy populations and as well as those with impairment of the motor control system.

Level of Evidence: Level 2b (Observational study of validity)1 Key Words: Accelerometer, Single Leg Balance Test, Smartphone Application, Stability assessment

1

Department of Human Performance Studies, Wichita State University, Wichita, KS, USA 2 Department of Industrial and Manufacturing Engineering, Wichita State University, Wichita, KS, USA

CORRESPONDING AUTHOR Jeremy A. Patterson, PhD, FACSM Department of Human Performance Studies, Wichita State University 1845 Fairmount, Wichita, KS, 67260-0016 Phone: (316) 978-5440 Fax: (316) 978-5451 E-mail: Jeremy.patterson@wichita.edu

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 135

INTRODUCTION Human balance is a general term used to describe the coordination of complex sensory, motor, and biomechanical processes for the purpose of maintaining one’s center of mass (COM) with respect to their base of support (BOS).2,3 The ability to maintain balance, or postural stability, is an essential component in motor skills ranging from simply maintaining posture to performing complex voluntary movements.4,5,6 Improving balance has been shown to help with recovery from injury, injury prevention, and improved functional performance in both young and elderly individuals.4,7,8 As such, the ability to quickly and reliably assess balance for any population, in any clinical, recreational, or wellness setting is becoming increasingly important.

Multiple methods of assessing balance, both objective and subjective, have been developed. Subjective assessment methods vary widely in testing methodology. They generally include a set of testing and scoring procedures unique to the test chosen, and tend to be utilized in clinical settings. Here a test administrator utilizes their clinical knowledge and experience to evaluate the patient. The benefits of these balance tests are that they are easily administered and require little to no equipment. However, while many have been validated, they do not provide quantifiable data and rely on the skill and experience of the test administrator for scoring and interpretation.9 Objective methods of balance assessment include the use of force platforms, strain gauges, and accelerometers. The benefits of these devices are their ability to generate quantitative scores by which clinicians and researchers are able to track change over multiple tests. However, while these test methods have improved validity and reliability over subjective methods, with the exception of accelerometers, the equipment needed is generally large and difficult to transport.9 This makes equipment-based balance assessments difficult to perform when outside of the clinical or laboratory environment. Accelerometers, on the other hand, are small, lightweight, and able to be attached to the subject. Additionally, they have been shown to be useful for assessing balance during both static and dynamic activities.10,11 However, despite their advantages over other objective measures, accelerometers are still primarily only used in

laboratory settings, thus limiting widespread clinical use of this balance assessment method.9,12 As technology has advanced, there has been an increase in the prevalence of consumer electronics, which incorporate the use of multiple accelerometers.

One such advancement can be found in the iPod and iPhone developed by Apple Inc. These systems incorporate Micro Electro-Mechanical Systems (MEMS) nano-accelerometers that measure the instantaneous acceleration of an object, compared to gravity at any given time, in a free-fall reference frame. Measurements are accomplished using a moveable bar suspended on micro-machined springs that quantify acceleration by the deflection of the bar as the device moves in reference to gravity.12 MEMS accelerometers typically incorporate three measurement axes that quantify acceleration independently, yet are housed in the same device. These accelerometers are termed tri-axial or tri-axis accelerometers.

The concept of a wireless accelerometer system for quantifying the attributes of gait and balance has been illustrated through the G-linkÂŽ Wireless Accelerometer Node and Apple iPod and iPhone.13,14,15,16,17,18 These devices have the capacity to store data samples, which can be conveyed wirelessly to a remote location for post-processing. Several authors have indicated that the iPod and iPhone demonstrate the capacity to accurately acquire quantified balance parameters with a sufficient level of consistency.16,18,19 However, further studies are needed to continue to validate the accuracy and reliability of accelerometric mobile devices. Furthermore, there is a need to validate the accuracy and reliability of smart phone applications utilizing accelerometry.

The current study utilized the Biodex Balance System SD (Biodex Medical Systems, Shirley, NY, USA) and the SWAY Balance Mobile Application (SWAY Medical, Tulsa, OK, USA) installed on an Apple iPod Touch device (Apple Computer Inc., Cupertino, CA, USA). The Biodex system uses a circular platform that is free to move about the anterior-posterior (AP) and medial-lateral (ML) axes simultaneously, and measures the degree of tilt about each axis. The device then calculates the medial-lateral stability index (MLSI), anterior-posterior stability index (APSI), and the overall stability index (OSI) by

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 136

means of strain gauges, which measure the change in pressure and force within the springs of the underside of the platform.20,21 The units representing the stability index are interpretations of the change in strain, determined by undisclosed calculations from Biodex Medical Systems, Inc. Conversely, the SWAY Balance Mobile Application, installed on the mobile device, accesses the output generated from the triaxial accelerometers to determine a balance (stability) score. The units representing the balance score are interpretations of the acceleration of deflection within the accelerometers, and are also determined by undisclosed calculations from SWAY Medical.

The purpose of this pilot study was to assess the value and validity of using software developed to access the iPod and iPhone accelerometers output and translate that to the measurement of human balance.

METHODS Thirty healthy college-aged individuals (13 male, 17 female; mean age = 26.1 + 8.5 yr) free from any preexisting condition that may have altered their ability to balance normally participated in this study.

All testing procedures were approved by the Wichita State University Institutional Review Board for Research involving Human Subjects, and informed consent was obtained from all subjects prior to participation.

Subjects performed a single trial of the Athlete Single Leg Test protocol, requiring them stand on their non-dominant foot for 10 seconds on a Balance System SD platform. Subject height and weight were recorded and foot placement on the platform was conducted following manufacturer recommendations. Postural sway was concurrently measured utilizing an Apple iPod Touch loaded with the SWAY Balance Mobile Application software. Subjects were instructed to hold the iPod in an upright position, and with the screen side of the device against the approximate mid-point of their sternum. The Balance System SD and SWAY tests were initiated and terminated simultaneously in order to maintain synchronized recording. Upon completion of the test, the Anterior-Posterior Stability Index (APSI) score generated by Biodex and anterior-posterior postural sway data generated by the SWAY Balance Mobile Application were exported for analysis. Statistical

analysis for this study were completed with the use of Statistical Packages for the Social Sciences (SPSS) version 17.0.

RESULTS Data are summarized in Table 1. Preliminary data showed strong consistency in the SWAY Balance Mobile Application Software outcomes when compared to those from the BIODEX Balance System SD (Figure 1). APSI Scores on the balance platform were 1.41 + 0.90 compared to 1.38 + 0.72 using the SWAY Balance Smartphone Application. Paired samples tTest revealed no significant difference between the mean sway measures for the subjects when measured by each device (p = 0.818). A significant correlation between the two data sets was found with a mean difference (0.030 + 0.713) (p < 0.01, r = 0.632) (Figure 2).

DISCUSSION Balance assessment tools can be utilized to assess the neuromuscular effects of aging, identify neurological disorders, aid in the diagnosis of injury related to brain trauma, and identify functional deficits related to activities of daily living. Additionally, Table 1. Data Summary

Figure 1. Consistency in balance scores between Biodex Balance System SD and SWAY Balance Smartphone Application.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 137

Figure 2. The difference in measured balance scores between the Biodex Balance System SD and SWAY Balance Smartphone Application. The mean difference (0.030 + 0.713) showed a significant correlation between the two methods.

the implementation of a balance training program can aid in injury prevention, be used as a prescriptive rehabilitative tool in injury recovery, reduce the risk of falls in the aging, enhance functional or athletic performance, as well as provide a better overall understanding of the physiological systems contributing to postural movement and stability.5,6,22,23,24 Though balance training programs and assessments are being utilized for many conditions and populations, proper assessment and measures of balance must be determined in order to select the appropriate method of balance training. For implementation of balance training programs to be successful, assessment protocols must be reliable, valid, reproducible, and sensitive enough to measure minor changes. In a study that ran concurrently with this pilot study, the author’s tested five iPod Touch devices in order to determine the sensitivity of the acceleration outputs.25 The results demonstrated low coefficients of variability, suggesting that sensitivity values in these devices are highly consistent. Appropriate software accessing these outputs would be capable of sensing small movements associated with postural stability.

The purpose of this pilot study was to determine the consistency of a mobile device application that accesses data from the tri-axial accelerometers within the iPod Touch for assessing human balance.

Preliminary results from this pilot study demonstrate that software used to access the tri-axial accelerometers within the iPod/iPhone may be a useful

method for assessing balance. However, this is a pilot study and is limited in scope. At the time this study was conducted the SWAY Balance Mobile Application was in its beta version and unavailable on the market. This version of the software accessed the iPod Touch accelerometers to only measure movement in the anterior/posterior plane. The reason for this was to determine if the consistency between the Biodex Balance System SD and the SWAY Balance Mobile Application measures were sufficiently acceptable to continue with the further development of the SWAY Balance assessment. Since the completion of this pilot study, the software has been updated to capture both anterior/posterior as well as medial/lateral movement. Subsequent studies are currently underway assessing the additional balance parameters that can be evaluated using this software update. Despite the limitations in the SWAY Balance software, the results of the current study showed consistency in output when compared to the Biodex Balance System SD. Further studies will determine the validity and reliability of the final version of the SWAY Balance Assessment. It is also worth noting that the study participants were a sample of convenience, all were undergraduate students of Exercise Science and familiar with methods of assessing human balance.

CONCLUSION The information obtained from this pilot study can be of benefit to medical professionals, physical education coaches, parents, and the athletic community.

There is an unmet need for a convenient, easy to use, cost-effective tool to measure balance. A device meeting those criteria would be an important development in the task of identifying individuals with postural instability. Results from this initial pilot are promising. Balance measures, although with a small sample size, were consistent with measurements obtained using a previously validated system, demonstrating concurrent validity of the measurement using the SWAY application on a handheld device.

However, recent updates in the SWAY application warrant further studies in order to assess its reproducibility, both in a healthy population and in a population with impairment of the motor control system.

REFERENCES 1. OCEBM Levels of Evidence Working Group. “The Oxford Levels of Evidence 2”. Oxford Centre for

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 138

2.

3.

4.

5.

6.

Evidence-Based Medicine. http://www.cebm.net/ index.aspx?o=5653 Pollock, A. S., Durward, B. R., Rowe, P. J., et al. What is balance? Clin Rehabil. 2000;14:402-406.

Rose, D. J. Balance, Posture, and Locomotion. In W. W. Spirduso, K. L. Francis & P. G. MacRae (Eds.), Physical Dimensions of Aging (2nd ed.). Champaign, IL: Human Kinetics, 2005: 131-151.

Rogers, M.E., N.L. Rogers, N. Takeshima. Balance training in older adults. Aging Health. 2005;1(3):475486.

Guskiewicz, K. M., Perrin, D. H. Research and clinical applications of assessing balance. J Sport Rehabil. 1996;5:45-63.

Woollacott, M. H., Shumway-Cook, A. Concepts and methods for assessing postural instability. J Aging Phys Activ. 1996;4:214-233.

7. Davlin, C. D. Dynamic balance in high level athletes.

Percept Motor Skill. 2004;83(3,Pt2): 1171-1176.

8. Alexander, N.B., Postural control in older adults.

J Am Geriatr Soc. 1994;42(1):93-108.

9. Rogers, M. E., Rogers, N. L., Takeshima, N., et al.

Methods to assess and improve the physical parameters associated with fall risk in older adults.

Prev Med. 2003;36:255-264.

10. Cho, C. Y., Kamen, G. Detecting balance deficits in frequent fallers using clinical and quantitative evaluation tools. J Am Geriatr Soc. 1998;46(4):426430.

11. Yack, H. J., Berger, R. C. Dynamic stability in the elderly: Identifying a possible measure. J Gerontol.

1993;48(5):M225-M230.

12. Culhane, K. M., O’Connor, M., Lyons, D., et al.

Accelerometers in rehabilitation medicine for older adults. Age Ageing. 2005;34(6):556-560.

13. Lemoyne, R., Coroian, C., Mastroianni, T., Grundfest, W. Accelerometers for quantification of gait and movement disorders: A perspective review.

J Mech Med Biol. 2008;8(2):137-152.

14. LeMoyne, R., Coroian, C., Mastroianni, T. Wireless accelerometer reflex quantification system characterizing response and latency. Presented at: Annual International Conference of the IEEE; Sept 3-6, 2009; Minneapolis, MN. 15. Lemoyne, R., Coroian, C., Mastroianni, T. Wireless accelerometer system for quantifying gait. Presented

at: International Conference on Complex Medical Engineering; April 9-11, 2009; Tempe, AZ. 16. LeMoyne, R., et al. Wireless accelerometer iPod application for acquiring quantified gait attributes.

Presented at: 5th Frontiers in Biomedical Devices Conference and Exposition, New York, American Society of Mechanical Engineers; Sept 20-21, 2010; Newport Beach, CA. 17. Lemoyne, R., et al. Implementation of an iPhone for characterizing Parkinson’s disease tremor through a wireless accelerometer application. Presented at: 32nd Annual International Conference of the IEEE EMBS; Aug 31-Sept 4, 2010; Buenos Aires, Argentina.

18. Lemoyne, R., Mastroianni, T., & Grundfest, W. Wireless accelerometer iPod application for quantifying gait characteristics. Presented at: 33rd Annual International Conference of the IEEE EMBS; Aug 30-Sept 3, 2011; Boston, MA. 19. Lemoyne, R., Mastroianni, T., Coroian, C., et al.

Wireless three-dimensional accelerometer reflex quantification device with artificial reflex system.

J Mech Med Biol. 2010;10(3):401-415.

20. Karimi, N., Ebrahimi, I., Kahrizi, S., et al. Evaluation of postural balance using the biodex balance system in subjects with and without low back pain. Pak J Med Sci. 2008;24(3):372-377.

21. Hinman, M. R. Factors affecting reliability of the Biodex Balance System: A summary of four studies.

J Sport Rehabil. 2000;9(3):240-252.

22. Bell, D.R., Guskiewicz, K.M., Clark, M.A., et al.

Systematic review of the balance error scoring system. Sports Health. 2011;3(3): 287-295.

23. Horak, F. B. Postural orientation and equilibrium: what do we need to know about neural control of balance to prevent falls? Age Ageing. 2006;35(suppl 2):ii7-ii11.

24. Tyson, S. F. How to measure balance in clinical practice. A systematic review of the psychometrics and clinical utility of measures of balance activity for neurological conditions. Clin Rehabil.

2009;23(9):824-840.

25. Amick, R.Z., Patterson, J.A. & Jorgensen, M.J. Sensitivity of Tri-Axial Accelerometers within Mobile Consumer Electronic Devices: A Pilot Study. Int J Appl Sci Tech. 2013; 3(2):97-100.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 139

IJSPT

ORIGINAL RESEARCH

FEASIBILITY AND RELIABILITY OF DYNAMIC POSTURAL CONTROL MEASURES IN CHILDREN IN FIRST THROUGH FIFTH GRADES Avery D. Faigenbaum1 Gregory D. Myer2,3,4 Ismael Perez Fernandez5 Eduardo Gomez Carrasco5 Nathaniel Bates2 Anne Farrell1 Nicholas A. Ratamess1 Jie Kang1

ABSTRACT Purpose/Background: Although dynamic postural control is a prerequisite to the development of fundamental movement skills in children, few studies have examined the feasibility and reliability of assessment techniques that measure dynamic postural control in youth under 13 years of age. Therefore, the purpose of this study was to determine the feasibility and reliability of the Lower Quarter Y Balance Test (YBT-LQ) in children and to examine the reproducibility of these measures across developmental periods of childhood.

Methods: 188 subjects in first through fifth grades (age = 6.9 to 12.1 yr) performed the YBT-LQ on two occasions in a field-based setting. Reach distances and cumulative score (sum of 3 directions) were measured and analyzed using intraclass correlation coefficients (ICC). Sub-cohorts of 14 and 8 subjects were used to assess inter-rater reliability within-session and between-session, respectively.

Results: The overall ICC was moderate-to-good for the anterior (right=0.82; left=0.82), posteromedial (right=0.77; left=0.75), and posterolateral (right 0.80; left=0.77) reach directions. The combined ICC was also moderate-to-good for children in grades 1 (0.71), 2 (0.74), 3 (0.84), 4 (0.82), and 5 (0.79). Typical error values for right and left limbs were less than 10% of the mean for all reach measures across all grades. Interrater reliability within session (ICC > 0.995) and between sessions (0.907 ≤ ICC ≤ 0.974) were both excellent. No unexpected responses or injury occurred during testing.

Conclusions: These findings indicate that the YBT-LQ is a feasible and reproducible measure of dynamic postural control in children in first through fifth grades.

Level of Evidence: 2b Key Words: Assessment, balance, postural stability, skill-related fitness, youth

1

The College of New Jersey, Ewing, New Jersey, USA Cincinnati Children’s Hospital Medical Center, Division of Sports Medicine, Cincinnati, Ohio, USA 3 Department of Pediatrics and Orthopaedic Surgery, College of Medicine, University of Cincinnati, Ohio, USA 4 The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA 5 Universidad Europea de Madrid, School of Physical Activity and Sport Science, Madrid, Spain 2

Grant Support: American Council on Exercise Institutional Review Board Approval: The Institutional Review Board at The College of New Jersey approved this study (protocol number 1118-06) on September 29, 2011.

Acknowledgements: This study was supported by a grant from the American Council on Exercise. The authors thank Bud Kowal, Eileen Kowalsky and the Ewing Township School District (NJ) for their support of this research study. The authors also thank Joelle Bagley and Shannon Boise for their assistance with data collection

CORRESPONDING AUTHOR Dr. Avery Faigenbaum, Ed.D, CSCS, FACSM, FNSCA Department of Health and Exercise Science The College of New Jersey 2000 Pennington Rd Ewing, NJ 08628 USA Email: faigenba@tcnj.edu

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 140

INTRODUCTION A variety of fitness test batteries are currently used to assess physical fitness and sports performance in youth.1-3 Data from these tests can be used to specifically target areas in need of improvement and educate youth about the importance of regular participation in a variety of fitness activities. Moreover, clinicians use fitness test data to identify young athletes at increased risk of injury and design conditioning programs to enhance sports performance.

Despite the popularity of field-based measures such as the one-mile run and push-up test, the use of skillbased measures that require dynamic postural control have received less attention in children. The lack of data on skill-based testing in youth is noteworthy since low competency in fundamental movement skills is strongly associated with lower cardiorespiratory fitness during the growing years.4 Furthermore, youth who have not mastered fundamental movement skills may be less likely to participate regularly in organized sports and play experiences.5 These findings have important public health implications since low levels of habitual physical activity have been found to increase the risk of injury in children during physical education class, leisure time activity, or sport.6 Moreover, youth who do not develop at least a basic level of motor skill performance by the end of adolescence may be less likely to demonstrate at least fair levels of health-related fitness in early adulthood.7 The ability to stabilize the body and maintain postural control during dynamic actions is critical for the successful performance of fundamental movement skills such as kicking and jumping. One tool that assesses dynamic postural control is the Lower Quarter Y Balance Test (YBT-LQ).8 The goal of the YBT-LQ is to maintain single-leg stance balance while reaching as far as possible with the contralateral leg in the anterior (AT), posteromedial (PM) and posterolateral (PL) directions. The available data indicate that tests of dynamic postural control are reliable for measuring single leg excursion distances in adolescents and adults.8-10 For example, Plisky et al. examined the reliability of the YBT-LQ in collegiate soccer players and reported intraclass correlation coefficients (ICC) for intrarater and interrater reliability between 0.85 to 0.91 and 0.99 to 1.00, respectively.8

Despite the importance of dynamic postural control as a prerequisite to the development of fundamental movement skills in children, to the authorâ&#x20AC;&#x2122;s knowledge no data on the reliability of unilateral dynamic balance in school-age youth under 13 years of age are available. Similarly, of the few studies that examined balance in children,11,12 no studies have assessed the ability of children in grades 1 to 5 to perform a unilateral dynamic balance test that requires strength, flexibility, and proprioception. Since reliable tests are the foundation of the ability to properly assess and monitor childrenâ&#x20AC;&#x2122;s fitness and performance, additional research is needed to determine the reliability of unilateral dynamic balance in children and to examine the reproducibility of these measures throughout early childhood. This information is particularly important relative to the growing interest in physical fitness testing and injury prevention strategies in youth.13,14 Therefore, the purpose of this study was to determine the feasibility and reliability of the YBT-LQ in children in first through fifth grades, and to examine the reproducibility of these measures across developmental periods of childhood.

METHODS Participants Study participants were a convenience sample of 188 children attending an urban public school in New Jersey, USA, between 2011 and 2012. Children (97 male, 91 female) in grades one (n= 42), two (n = 37), three (n = 22), four (n = 43) and five (n= 44) volunteered to participate (Table 1). Participants had no prior experience performing the YBT-LQ. Exclusion criteria included any lower extremity injury, medical condition, or disability that limited participation in physical activity. This study was approved by the Institutional Review Board at The College of New Jersey as well as the administration at the participating school. All parents provided written permission and all children provided assent before the start of the study.

Study Protocol All participants (n = 188) performed the YBT-LQ on two occasions separated by 7 to 10 days in a school gymnasium. A rater assessed each participantâ&#x20AC;&#x2122;s standing height to the nearest 0.5 cm on stadiometer and body mass in light clothing to the nearest 0.1 kg

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 141

Table 1. Demographic and anthropometric characteristics of study participants

using a digital scale. Prior to formal testing, subjects performed 3 minutes of calisthenics (e.g., jumping jacks and standing march) and six practice trials on each leg in each of the three reach directions. Due to the amount of time needed for administering the YBT-LQ to a large group of children, three practice trials were performed in a group setting (rater-tochild ratio of 1 to 5) using floor tape in a Y-shape and a small foam box as the reach indicator. During these practice trials, raters highlighted the importance of maintaining single-leg stance and participants practiced the desired action in three reach directions on both legs. Three additional practice trials as well as all formal YBT-LQ procedures were performed on a commercially available Y-Balance kit (Move2Perform, Evansville, IN) under close supervision (raterto-child ratio of 1 to 1). Five testing stations were present and participants were tested in groups of 20 to 25. Raters who completed an online YBT-LQ certification and had experience administering the YBTLQ served as administrators.

In order to assess interrater reliability (observer error), two raters who were blinded to each otherâ&#x20AC;&#x2122;s scoring simultaneously observed and rated a single trial performance on a subsample of 14 participants in this study. In addition, interrater reliability (performance error) was assessed by two different raters who scored 8 participants performing separate trials of the YBT-LQ for each rater on the same day.

The Y-Balance kit consists of a stance platform to which three pieces of polyvinylchloride pipe are attached in the AT, PM, and PL reach directions (Figures 1a,1b, and 1c). Each pipe is marked in 0.5 cm increments for measurement. To perform the YBTLQ, the participant stood on one foot on the center foot plate with the most distal aspect of the toes just behind the starting line. The starting position for the reach foot was between the center foot plate and the pipe opposite the stance foot. While maintaining single-leg stance, the participant was instructed to push the reach indicator along the pipe with the reach foot as far as possible in the direction being tested; and then return the reach limb to the starting position resuming a bilateral stance. Participants were not given specific strategies to enhance performance.

The maximal reach distance was measured by reading the tape measure at the edge of the reach indicator, at the point where the most distal part of the foot reached in half centimeters. The reach was discarded and repeated if the subject failed to maintain unilateral stance on the platform, failed to maintain reach foot contact with the reach indicator, used the reach indicator for stance support or failed to return the reach foot to the starting position under control.

The testing order was three trials standing on the right foot reaching in the AT direction followed by three trials standing on the left reaching in the AT direction. This procedure was repeated for the PM and the PL directions. The specific testing order was right AT, left AT, right PM, left PM, right PL, and left PL. If a proper reach was not performed in three trials for any direction, an additional three trials were allowed. The furthest successful reach for each direction was used as an indication of dynamic postural control and for analysis. A total combined score was based on the sum of performance in three reach directions on both legs. Each participant wore the same athletic shoes during testing sessions.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 142

Figure 1. Figures 1a, 1b, 1c, Performance on the Y balance test in the anterior (1a), posteriomedial (1b) and posterolateral (1c) reach directions.

In order to make the testing experience more enjoyable and age-appropriate for children, we modified the YBT-LQ and created a game called the “sleeping alligator” whereby the participants imagined they were a bird standing on a small island (center foot plate) and all around them was swampy water (the floor) filled with alligators (the three reach indictors). As a pedagogical cue, subjects were reminded to slowly push the alligators away using one foot while maintaining balance so they would not fall into the swamp. We placed child-friendly alligators made from green cloth on top of each reach indicator. YBT-LQ procedures (including warm-up trials) took approximately 10 minutes per participant.

Data Analysis The data were analyzed for each subject, in each grade, for the right and left leg in the AT, PM and PL directions. In addition, a total combined score, which was based on the sum of performance in the three reach directions on each leg, was analyzed by grade. Descriptive statistics were calculated for all variables. The relative reliability of the data was determined using intraclass correlation coefficients (ICC, 3,1). Interrater reliability was calculated for two different scenarios. ICCs were calculated for separate raters’ evaluations of the same subject performing the same trial and separate raters’ evalua-

tions of the same subject performing separate trials within the same session. These calculations defined the reliability for observer error within-trial and the subject performance error between-trials, respectively. Single-rater, between-session reliability was also calculated for each individual grade level.

The range of ICC values was described using the classifications of Fleiss, where ICC < 0.4 was considered poor, 0.4 < ICC < 0.75 was considered fair-to-good, and ICC > 0.75 was considered excellent.15 Typical error analyses (square root of mean square error) were also used to evaluate reliability as typical errors can help establish the range at which differences in absolute values become clinically significant16. Data are reported as means and SDs and statistical significance was set at p < .05. Statistical procedures were performed using SPSS version 17.0 for windows (Chicago, IL) and SAS version 9.1 (SAS Institute, Cary, NC).

RESULTS All participants completed the aforementioned study procedures as described. No unexpected events or injury were reported. Performance data for each grade, represented as means and standard deviations in centimeters of the maximal reach distance for the AT, PM, and PL reach directions while standing on the right and left foot for both testing trials, are presented in Table 2.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 143

Table 2. Performance data for each grade, represented as means and standard deviations in centimeters of the maximal reach distance for the anterior, posteromedial, and posterolateral reach directions while standing on the right and left foot for testing session 1 and 2

Interrater reliability within session, within trial (Observer Error) When different raters observed the same participant performing the same test trial, the interrater ICCs for the YBT were excellent for all variables. Testers demonstrated nearly perfect correlation as ICCs were all greater than 0.995 for the AT, PM, PL and composite directions on both the right and left limbs. There was no side-to-side difference observed in these ICC measures. Typical “observer” error for each individual reach variable was between 0.14–0.61 cm, which was less than 1% of the total range for shortest reach variable. Composite typical error was 0.98 for the right leg and 0.92 for the left leg, both of which were less than 0.4% of the total range of composite reach.

Interrater reliability within session, between trials (Performance Error) When different raters observed the same participant performing separate test trials, the inter-rater

ICCs for the YBT were also excellent for all variables tested. ICCs ranged between 0.907–0.990 for AT, PM, PL and composite reach on both limbs when separate test instances were examined. The combined inter-rater ICCs were nearly identical between sides as the right limb value was 0.947 and the left limb was 0.949. Typical “performance error” for each individual reach variable was between 1.51–2.53 cm, which individually represented less than 3.3% of the total range of reach for each variable. Composite typical error was 2.68 cm for the right leg and 3.13 cm for the left leg, both of which were less than 1.5% of the total range of composite reach.

Single-rater between-session reliability by grade level For subjects of all grades, the overall ICC was moderate-to-good for the AT (right = 0.82; left = 0.82), PM (right = 0.77; left = 0.75), PL (right = 0.80; left = 0.77) and composite (right = 0.88; left = 0.88) reach

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 144

Table 3. Intraclass correlation coefďŹ cients (ICC) and typical error by grade

directions. The combined ICC was also moderate-togood for participants in grades 1 (0.71), 2 (0.74), 3 (0.84), 4 (0.82), and 5 (0.79).

Typical errors for individual and composite leg reach variables on the YBT-LQ are represented for each grade level in Table 3. Typical error values were less than 10% of the mean for all reach measures across all grade levels. These relative percentages of error were largest within the first grade population (8.0%), decreased through third grade (4.8%), and leveled off in fourth (5.4%) and fifth grades (5.9%). For all grade levels, typical error during the AT reach (3.49 cm) was less than the PL (4.97 cm) and PM (4.89 cm) reaches which were less than the composite (9.20 mm) reach. No correlation between change in grade level and increase or decrease in typical error values was identified. However, participants in third grade demonstrated the lowest typical error values for all individual reach variables. Typical error for individual and composite reach measures across the study population did not demonstrate differences in excess of 0.52 cm between the right and left limbs. When the population was broken down by grade level, performance differences in typical error between right and left limbs were very similar and exceeded 1.0 cm for only fourth grade PL and fifth grade PM directions.

DISCUSSION Since motor skill competence early in life appears to form the foundation for a lifetime of physical activity,7,17 it is increasingly important to establish reliable assessments that can be used to monitor and

assess skill-related fitness components in children.

The current study examined the reliability of the YBT-LQ in children in first through fifth grades in a field-based setting. The present findings support the results of others who examined the reproducibility of postural control assessments in adolescents and adults,8-10 and indicate that the YBT-LQ is both a feasible and reliable assessment of unilateral balance and dynamic neuromuscular control in healthy children. In this investigation, 188 children performed the YBT-LQ on two occasions following standardized procedures and no untoward events were reported. Importantly, the reproducibility of unilateral dynamic balance performance was found to be relatively consistent in a large sample of children in grades one to five, and this could have important implications for assessing motor control development in school-age youth. However, it must be underscored that performance on the YBT-LQ was evaluated by trained raters who consistently followed standardized testing procedures.

Although data on test-retest reliability of unilateral dynamic balance in children is limited, the current findings are supportive of previous reliability assessments in cohorts of older subjects.8-10 For example, Filipa et al. noted intrarater ICCs of 0.81 to 0.96 for the three reach directions in adolescent athletes9 and Plisky et al. reported intrarater ICCs from 0.82 to 0.87 for the three reach directions in a sample of high school basketball players.10 Geldhof et al. reported ICCs between 0.62 to 0.80 in 9 to 10 year old children who performed a clinical test of postural stability (Balance Master) that quantified static

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 145

and dynamic standing balance using a portable force plate.12 Of note, in the current study, ICCs were greater for the overall population than the sample populations for each grade level. As the number of subjects within a population increase, the variance is likely to decrease as outlying cases will be muted by the increased weight of the overall population mean.

In the present investigation, the sample populations had approximately five times fewer subjects than the overall population. This demographic could have allowed outliers to increase the relative variability within each grade level, which would decrease the ICC values. This phenomenon can again be seen as the composite ICC values for each grade level were greater than any of the ICCs reported for individual measures within that grade level.

In the current study, the composite reach variable expressed both greater ICC correlations and greater error than individual reach measures. This finding corresponds with previous Y-Balance Test reliability studies performed on active military personnel.18 Although the magnitude of error in the composite measure increased compared to the individual reach measures, it represented a smaller percentage of change than was seen in the score magnitude between an individual and composite reach. Therefore, the composite values demonstrated the most reliable ICCs. The typical error for individual and composite reach measures across the study population did not demonstrate side-to-side differences. However, when the population was broken down by grade level, side-toside differences in typical error exceeded 1.0 cm in selected grades and reach directions. Although other researchers reported no difference in unilateral postural stability between dominant and non-dominant limbs in healthy young adults,19,20 the current observations are important to physical therapists and other clinicians who use side-to side comparisons to assess performance or identify aberrant motor control patterns as increased error is typically indicative of reduced control.21,22 The relative measures of typical error for the right and left limbs were largest within the first and second grade populations (Figure 2). Participants in third grade demonstrated the lowest typical error values

Figure 2. Typical error as a percentage (%) of mean reach distance for the right (top) and left (bottom) limbs.

for individual reach variables on their right limb, whereas relative measures of typical error for the left limb in the anterior and posterior-lateral reach directions were lowest in the fifth grade population.

While the maturation of the neurological, visual, vestibular and proprioceptive systems are important considerations when evaluating balance performance during the growing years,11 factors related to somatotype, habitual physical activity, and mental engagement should also be considered. Basic motor skills are reaching mature form between five and eight years of age,23 and these skills continue to be refined and improved as the child finds new solutions to efficient movement. Also, changes in somatotype during early childhood which are characterized by a redistribution of subcutaneous adipose tissue, the development of muscle tissue, and the lengthening of the legs relative to stature may influence postural stability in children.23,24 Age-related improvements in motor skill performance and muscle strength may have had an observable influence on dynamic balance in the current investigation. The YBT-LQ is a relatively challenging assessment that requires strength, flexibility, proprioception, and concentration coupled with motion at the ankle, knee and hip joints. Each reach direction requires different activation of the lower extremity muscles25. In addition, trunk motion is required as the child attempts to maximize reach distance in different directions. As the foot reaches in the targeted direction, the childâ&#x20AC;&#x2122;s center of mass is moved in rela-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 146

tion to the base of support and adequate neuromuscular control is needed to consistently perform the test. Due to environmental as well as maturational influences, children entering third grade (about nine years of age) may have developed more efficient movement strategies and muscle strength that could be applied to a constrained task that required postural control and balance. Younger subjects may not have developed the motor control necessary to consistently reproduce dynamic motions and therefore may be likely to express lower reliability score in measures of dynamic postural control.

From a practical perspective, youth fitness tests should be able to detect small but significant changes in performance and provide meaningful information to clinicians and pediatric researchers. The current findings indicate that the methods employed in this study are feasible and reliable for assessing dynamic postural control performance in children in a fieldbased setting, although raters should be mindful of the challenges associated with administering fitness tests to young children. The reproducibility of the test and acceptable measurement error in this study was likely due to a number of factors. As per standard YBT-LQ testing guidelines, all participants had an opportunity to become familiar with the test and practice the desired movements while receiving constructive feedback on the quality of their performance from a trained rater. A standard testing order was followed and well-defined criteria were used to define a successful reach. Also, the YBT-LQ was modified by using the “sleeping alligator” game as a pedagogical cue in order to stimulate interest in the desired task, maintain attention, and make the experience enjoyable for the children.

Despite the growing interest in the relationship between health- and skill-related fitness measures in school-age youth, normative data for dynamic balance in children are not yet available for comparison.

Nevertheless, these findings indicate that the YBT-LQ can be used to quantify unilateral dynamic balance performance in healthy children in grades 1 to 5.

Although these findings may not be generalizable to children with physical limitations, administration of dynamic balance assessments in field-based settings could be used to teach children about skill-related components of physical fitness and identify children

at increased risk of injury. Moreover, due to low levels of fundamental movement skill competency in children,26 the assessment of dynamic postural control may be an important measure in interventions designed to promote physical activity and improve fitness performance in school-age youth. In the present investigation, grade level and chronological age were used instead of maturational age and we recognize that growth and maturation can influence fitness performance during childhood.

CONCLUSION To the author’s knowledge, no other study has examined the feasibility and reliability of the YBT-LQ in children. Measures of inter-rater reliability were substantial and test-retest reliability scores in children in first through fifth grades were consistent over 7 to 10 days. Typical error values were less than 10% of the mean for all reach measures across all grade levels and these observations could be considered clinically significant. These substantive findings fill the gap of prior literature that focused on measures of dynamic balance in adolescents and adults, and provide valuable information for the use of this dynamic postural control assessment as a tool to quantify normal motor control development in healthy children. Since compromised stability and poor postural control may hinder a child’s ability to master fundamental movement skills and, in turn, participate in recreational and sporting activities as an ongoing lifestyle choice, further research is recommended to establish age-related strategies to enhance dynamic balance and postural control in school-age youth.

REFERENCES 1. Institute of Medicine (IOM). Fitness Measures and Health Outcomes in Youth. Washington, DC: The National Academies Press; 2012.

2. President’s Council on Physical Fitness Sports and Nutrition. Physical Educator Resource Guide; 2012.

3. Faigenbaum A, Westcott W. ACE Youth Fitness Manual. San Diego, CA: Americn Council on Exercise; 2013.

4. Hardy L, Reinten-Reynolds T, Espinel P, Zask A, Okely A. Prevalence and correlates of low fundamental movement skill competency in children. Pediatrics. 2012;130:e390-e398.

5. Okely AD, Booth, M., Patterson J. Relationship of physical activity to fundamental movement skills

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 147

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

among adolescents. Med Sci Sports Exerc.

2001;33:1899-1904.

Bloemers F, Collard D, Paw M, Van Mechelen W, Twisk J, Verhagen E. Physical inactivity is a risk factor for physical activity-related injuries in children. Brit J Sports Med. 2012;46:669-674.

Stodden D, True L, Langendorfer S, Gao Z. Associations among selected motor skills and healthrelated fitness: Indirect evidence for Seefeldt’s proficiency barrier theory in young adults? Res Q Exerc Sport. 2013;84:397-403.

Plisky P, Gorman P, Butler R, Kiesel K, Underwood F, Elkins B. The reliability of an instrumented device for measuring components of the star excursion balance test. North Am J Sports Med Phys Ther.

2009;4:92-99.

Filipa A, Byrnes R, Paterno M, Myer G, Hewett T. Neuromuscular training improves performance on the star excursion balance test in young female athletes. J Ortho Sports Phys Ther. 2010;40:551-558.

Plisky P, Rauh M, Kaminski T, Underwood F. Star excursion balance test as a predictor of lower extremity injury in high school basketball players.

J Ortho Sports Phys Ther. 2006;36:911-919.

Mickle K, Munro B, Steele J. Gender and age affect balance performance in primary school-aged children. J Sci Med Sport. 2011;14:243-248.

Geldhof E, Cardon G, De Bourdeaudhuij I, et al.

Static and dynamic standing balance: test-retest reliability and reference values in 9 to 10 year old children. Euro J Pediatrics. 2006;165:779-786.

Dumith S, Van Dusen D, Kohl H. Physical fitness measures among children and adolescents: are they all necessary? J Sports Med Phys Fitness. 2012;52:181189.

Stracciolini A, Casciano R, Levey Friedman H, Meehan W., Micheli L. Pediatric sports injuries: An age comparison of children versus adolescents. Am J Sports Med. 2013;epub ahead of print.

Fleiss, J., The Design and Analysis of Clinical Experiments. New York: Wiley; 1986.

16. Ford K, Myer G, Hewett T. Reliability of landing 3D motion analysis: implications for longitudinal analyses. Med Sci Sports Exerc. 2007;39:2021-2028.

17. Barnett L, Van Beurden E, Morgan P, Brooks L, Beard J. Does childhood motor skill proficiency predict adolescent fitness? Med Sci Sports Exerc.

2008;40:2137-2144.

18. Shaffer S, Teyhen D, Lorenson C, Warren R, Koreerat C, Straseske C. A reliability study involving multiple raters. Military Med. 2013;178:1264-1270.

19. Hoffman M, Schrader J, Applegate T, Koceja D. Unilateral postural control of the functionally dominant and nondominant extremities of healthy subjects. J Athl Train. 1998;33:319-322.

20. Lin W, Liu Y, Hsieh C, Lee A. Ankle eversion to inversion strength ratio and static balance control in the dominant and non-dominant limbs of young adults. J Sci Med Sport. 2009;12:42-49.

21. Myer G, Martin L, Ford K, et al. No association of time from surgery with functional deficits in athletes after anterior cruciate ligament reconstruction: evidence for objective return-to-sport criteria. Am J Sports Med. 2012;40:2256-2263.

22. Paterno M, Ford K, Myer G, Heyl R, Hewett T. Limb asymmetries in landing and jumping 2 years following anterior cruciate ligament reconstruction.

Clin J Sports Med. 2007;17:258-262.

23. Malina R, Bouchard C, Bar-Or O. Growth, Maturation and Physical Activity. 2nd ed. Champaign, IL: Human Kinetics; 2004.

24. Lee A, Lin W. The influence of gender and somatotype on single leg upright standing postural stability in children. J Appl Biomech. 2007;22:173-179.

25. Earl J, Hertel J. Lower extremity muscle activation during the Star Excursion Balance Test. J Sports Rehabil. 2001;10:93-105.

26. Hardy L, Barnett L, Espinel P, Okely A. Thirteenyear trends in child and adolescent fundamental movement skills: 1997-2010. Med Sci Sports Exerc.

2013;45:1965-1970.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 148

IJSPT

ORIGINAL RESEARCH

EFFECT OF INJURY PREVENTION TRAINING ON KNEE MECHANICS IN FEMALE ADOLESCENTS DURING PUBERTY Reiko Otsuki, PT, MSc1 Rieko Kuramochi, PhD2 Toru Fukubayashi, MD, PhD3

ABSTRACT Purpose/Background: Female adolescents change their landing mechanics during puberty. It is unknown whether implementation of anterior cruciate ligament (ACL) injury prevention training reduces the loss of knee control in female athletes during puberty. The purpose of this study was to evaluate the effect of injury prevention training on dynamic knee alignment in female basketball players specifically when the knee mechanics were changing during puberty.

Methods: Sixty female junior high school basketball players participated and were divided into two groups: a training group (n = 32) and a control group (n = 28). The training group underwent an injury prevention program for 6 months, whereas the control group maintained a regular training routine. The knee valgus motion and knee flexion range of motion during a drop vertical jump were measured before and after the training period. The probability of a high knee abduction moment (pKAM) was also evaluated using an ACL injury prediction algorithm.

Results: The knee valgus motion was significantly increased in the control group (p < 0.001), whereas it did not change in the training group (p = 0.64). Similarly, the knee flexion range of motion was significantly decreased in the control group (p < 0.001), whereas it was not changed in the training group (p = 0.55). The pKAM was significantly increased in the control group (p < 0.001), but not in the training group (p = 0.06).

Conclusions: Implementation of injury prevention training was effective in limiting the loss of knee control in female athletes during puberty. Lowering the risk of ACL injury might be possible in this population.

Level of Evidence: 2b Keywords: Anterior cruciate ligament, adolescent, female, injury prevention, landing

1

Doctoral student, Graduate School of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan 2 Lecturer, School of Health and Sport Sciences, Chukyo University, Toyota, Aichi, Japan 3 Professor, Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan Study approval: The protocol for this study was approved by the OfďŹ ce of Research Ethics of Waseda University.

Acknowledgements: The authors would like to acknowledge the participants, parents/ guardians, and coaches who volunteered for this study.

CORRESPONDING AUTHOR Reiko Otsuki 2-579-15 Mikajima, Tokorozawa, Saitama, Japan, 359-1192 Email: rotsuki@akane.waseda.jp Phone: +81-4-2947-6879 Fax: +81-4-2947-6879

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 149

INTRODUCTION Anterior cruciate ligament (ACL) injuries are one of the most common injuries in sports, specifically basketball. Female athletes between the ages of 14 and 19 years are among those who have the highest incidence of ACL injury.1-4 Injury to the ACL during this period is problematic because surgery in skeletally immature patients might cause growth disturbance. Also, surgery and rehabilitation prevent adolescents from participating in sports activities for a long period, affecting healthy physical development. In addition, regardless of management, the risk of developing osteoarthritis is significantly increased after an ACL injury.5-7 This could potentially affect later quality of life as well.

One of the risk factors for developing ACL injuries is poor lower extremity kinematics. Levine et al found that a combination of anterior tibial shear force, knee abduction, and internal tibial rotation led to ACL failure.8 In addition, video analysis of actual injury situations revealed that the main mechanisms of ACL injury were increased knee valgus motion with internal tibial rotation.9,10 A reduced knee flexion angle was also commonly observed in injury situations.9,10 Female athletes with an increased knee valgus motion and reduced knee flexion angle during landing are at a high risk of developing ACL injury.11 Female adolescents increase knee valgus motion following the onset of the pubertal growth spurt.12-14 Female athletes might also land with a reduced knee flexion angle after puberty as age increases.15 This phenomenon is probably the consequence of rapid physical development. In addition, female adolescents do not demonstrate sufficient neuromuscular adaptation to rapid skeletal growth like male adolescents.12 Since these changes in female adolescent movement patterns coincide with an increase in the number of ACL injuries, changes in landing mechanics might be a factor contributing to the increased incidence of ACL injuries in female athletes after the pubertal growth spurt.

Implementation of neuromuscular training strategies in children and adolescents to reduce the risk of developing ACL injuries has been recently encouraged.16 A meta-analysis revealed that implementing injury prevention training in the mid-teen years was

more effective in reducing ACL injury than in the late teen or early adult period.17 This finding suggests that injury prevention training should be initiated in young athletes.

Although injury prevention training seems to be effective in reducing the number of ACL injuries in adolescents, there is a need to understand the underlying mechanisms of this phenomenon. There is a lack of knowledge regarding the relationship between the changes in knee mechanics that may be associated with pubertal growth and injury prevention training. Several studies have evaluated the effect of injury prevention training on dynamic knee alignment in adolescents.18-20 However, it is still unknown whether injury prevention training is effective in limiting the movement pattern changes associated with pubertal growth in female adolescents.

To the best of the authorsâ&#x20AC;&#x2122; knowledge, no studies have investigated the effect of injury prevention training on knee mechanics, specifically during puberty.

Thus, the purpose of this study was to evaluate the effect of injury prevention training on dynamic knee alignment in female basketball players specifically when the knee mechanics were changing during puberty. The authors hypothesized that the implementation of an injury prevention training program in female basketball players during puberty could limit the loss of dynamic knee control.

METHODS Subjects Seventy-one female basketball players from five local junior high school basketball teams were recruited to participate in this study. A power analysis was performed based on a pilot study. Thirty-one subjects were needed in each group to achieve 80% power with alpha level of 0.05 (20% difference in pKAM means, pooled standard deviation of 30.8%, effect size of 0.65). All teams trained 6 days/week and had similar skill level. Subjects participated in the study during the first 6 months of a 12-month season. Subjects were excluded from the study if they had a history of ACL injury, a lower extremity injury within 6 weeks that prevented full participation in basketball, any medical or neurological pathology, or previously participated in an injury prevention program. Maturational stage was evaluated using

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 150

Table 1. Injury prevention training program.

the self-administered rating scale for pubertal development.21 Subjects were categorized into five maturational stages: pre-pubertal, early pubertal, middle pubertal, late pubertal, and post-pubertal. To evaluate pubertal subjects, females who were categorized at a pre- or post-pubertal stage were excluded from the study. There were 2 pre-pubertal and 4 postpubertal subjects. A total of 65 subjects participated in the study. Two teams (n = 36; age, 13.1 Âą 0.8 years) that were able to participate in the injury prevention training were assigned to the training group.

The other three teams (n = 29; age, 13.1 Âą 0.8 years) were assigned to the control group. A total of 60 subjects (training group: n=32; control group: n=28) completed the study and were analyzed. Four subjects from the training group and one subject from

the control group were unable to participate in the post-training testing session for personal reasons.

Injury prevention training An injury prevention training program (Table 1) was developed based upon previous literature.22-25 The program was modified considering basketball specific skills. The focus of this program was to ensure proper movement patterns, particularly avoiding knee valgus motion and encouraging knee flexion during landing and cutting. The program was 20 minutes long and was implemented as a warm-up routine. The training group performed the program three times per week for 6 months. A six-month training period was selected to observe the changes associated with growth. The initial training session

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 151

was conducted by a physical therapist. To ensure that the exercises were correctly performed and to help advance, the therapist followed up with the subjects every two weeks. The coach was also trained on how to instruct athletes on each skill at the initial training session. The coach led the training during the two weeks between therapist follow-ups. The control group performed their regular training routine for six months. Both groups did not perform any additional training or conditioning which may have had an influence on their landing performance.

Data collection Pre-training data were collected prior to the initial training session and post-training data were obtained after the 6-month training period in all subjects. An ACL injury prediction algorithm developed by Myer et al. was used to evaluate knee mechanics and ACL injury risk.26-28 This algorithm was reported to have high sensitivity and specificity and was able to identify female athletes who demonstrate a high knee abduction moment that increases the risk of ACL injury.26-28 Height, weight, and tibia length were measured.

Tibia length was measured as the distance between the lateral knee joint line and prominence of the lateral malleolus with the subjects standing with their knees extended. The quadriceps: hamstrings (QH) strength ratio was obtained using surrogate calculations by multiplying the female athlete’s body mass by 0.01 and adding the resultant value to 1.10.28 Two-dimensional lower extremity kinematics measurements were conducted. Eight bilateral markers were placed on each subject in the following locations: the greater trochanter, lateral knee joint line, patella, and lateral malleolus. Frontal and sagittal plane images were simultaneously captured with three video cameras (30 Hz; CASIO EXILIM, Japan).

A basketball goal was used as an overhead target.

The subjects performed a drop vertical jump (DVJ) as described previously.28 The subjects stood on a box (31 cm high) with their feet positioned 35 cm apart.

The subjects were instructed to drop off the box and immediately perform a maximum vertical jump, raising both arms towards the target. Prior to testing, the subjects were allowed to perform one to three practice trials to familiarize themselves with the test

maneuver. Once the subjects were able to perform the test maneuver, each subject performed three DVJ trials. No feedback was provided between the trials.

Data analysis Frontal and sagittal images of the first DVJ landing were analyzed. The video files were first de-interlaced using VirtualDub software (Avery Lee). Then the data were imported into ImageJ software (National Institute of Health, USA) to measure the knee valgus motion and knee flexion range of motion. The knee valgus motion was defined as the displacement between the patellar markers at the frame prior to initial contact and at the frame with a maximum medial position on the analyzing leg, and was calculated using the frontal view. The displacement measurements were calibrated using a known distance. The knee flexion angle was measured in the sagittal view with the angle made by the greater trochanter, lateral knee joint line, and lateral malleolus. The knee flexion range of motion was defined as the difference in the knee flexion angles at the frame prior to initial contact and maximum knee flexion. Using the tibia length, body mass, QH ratio, knee valgus motion, and knee flexion range of motion, the ACL injury prediction algorithm was used to obtain the probability of a high knee abduction moment (pKAM). Only the left leg was analyzed since previous literatures found that female athletes were more likely to tear their left ACL than the right.29-31 Based on these studies, left leg was analyzed to limit data from bilateral subjects with assumed normal growth and risk in both legs.

Statistical Analysis The mean and standard deviation of the knee valgus motion, knee flexion range of motion, and pKAM were calculated for each group. A 2 × 2 (group × time) analysis of variance with a mixed model design was conducted for each dependent variable. When there were significant interaction effects, a post hoc test was performed using a Bonferroni correction.

The alpha level was set at 0.05. SPSS Ver. 21 (SPSS Inc. Chicago IL, USA) was used to perform the statistical analysis.

RESULTS There were no statistically significant differences in the number of subjects in each stage between the

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 152

Table 2. Number of subjects in each pubertal stage.

Table 3. Subject demographics. Data are shown as mean ± SD. Training group: n = 32, control group: n = 28.

Table 4. Changes in the knee valgus motion, knee flexion range of motion, and probability of a high knee abduction moment (pKAM). Data are shown as mean ± SD.

training and control groups (p=0.09) (Table 2). No statistically significant differences were found between the training and control groups for age, height, or body mass at the two testing sessions (Table 3). Data for the knee valgus motion and knee flexion range of motion are summarized in Table 4. A significant group × time interaction was found for the knee valgus motion (p = 0.01), knee flexion range of motion (p = 0.01), and pKAM (p=0.02) (Figure 1). Post hoc analysis revealed that the knee valgus motion was significantly increased in the control group (p < 0.001), whereas it did not change in the training

group (p = 0.64) (Table 4). Similarly, the knee flexion range of motion was significantly decreased in the control group (p < 0.001); however, it did not change in the training group (p = 0.55) (Table 4).

The pKAM was significantly increased in the control group (p < 0.001), but not in the training group (p = 0.06) (Table 4).

DISCUSSION The incidence of ACL injury increases after puberty in female athletes.4 Recent authors have suggested that the biomechanical changes associated with

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 153

Figure 1. The pretest and posttest knee valgus motion, knee ďŹ&#x201A;exion range of motion, and pKAM in the training and control groups. *SigniďŹ cant difference between pretest and posttest (p < 0.001).

pubertal growth may contribute to the increased occurrence of ACL injury after puberty.12-15 Injury prevention strategies that minimize these biomechanical changes during puberty are necessary.

The results of this study support the hypothesis that the implementation of injury prevention training is effective in limiting the loss of dynamic knee control in female basketball players during puberty.

Although injury prevention training was able to limit the changes in knee mechanics, no improvement was observed. Previous studies evaluating high school female athletes found that injury prevention training improved knee mechanics in both the frontal

and sagittal planes.18-20 Although the methods of evaluating knee mechanics were different, it seems that the injury prevention training was not as effective in pubertal girls compared with post-pubertal girls.

This may be due to the changes in landing mechanics that pubertal girls naturally develop during this period. A rapid increase in height and weight might increase torque at the knee joint.32 In addition, the width of the pelvis increases in girls during puberty.

An increase in pelvic width might bring the hips to a more adducted position and therefore affect dynamic knee alignment.33 Moreover, it has been reported that female adolescents do not have a significant neuromuscular development during puberty compared with male adolescents.12 With a combination of structural and neuromuscular changes, pubertal girls demonstrate changes in landing mechanics. Implementation of injury prevention training could potentially enhance the neuromuscular system in female adolescents. Although a significant improvement might not be possible, limiting the changes in knee mechanics during this period might be a starting point to prevent ACL injury. In some athletes, this might be enough to reduce the risk of ACL injury, while in those who are at very high risk further training would need to be done. The effect sizes of the difference between the two groups in the knee valgus motion, knee flexion range of motion, and pKAM were Cohenâ&#x20AC;&#x2122;s d = 0.70, 0.79, and 0.61, respectively.

With these medium to large effect sizes, the authors believe that the posttest differences between the two groups were clinically important.

The pKAM in the training group was increased following the training period, although it was not statistically significant. This may be due to the physical growth factors, as the algorithm includes the body weight and tibia length. During the 6-month period, the height and weight of the training group subjects increased by 1.6 cm and 3.5 kg, respectively. Similarly, the control group subjects gained 1.1 cm in height and 2.7 kg in weight. These physical growth factors might have played a role when evaluating ACL injury risk in female adolescents.

One of the limitations of this study was that the knee kinematics was evaluated using two-dimensional measurements. Although a good correlation between twodimensional and three-dimensional analysis has been

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 154

reported in the previous studies,26,27 two-dimensional measures might not represent the complex 3 dimensional movements that occur about the knee during athletics. In addition, the use of the pKAM might not be as accurate as the laboratory-based assessment to evaluate the risk of ACL injury. However, the use of this assessment tool is less costly and easier to apply; thus, it is more clinically relevant. Another limitation was that the subjects in this study were junior high school students with an age between 12 and 14 years.

This age group might not be representative of all of the stages of puberty, as many of the subjects were categorized in the middle or late pubertal stages. In addition, in this study, randomization during group allocation and blinding of the examiner were not achieved. This may have produced unintentional biases. Also, the generalizability of the results of the present study was limited due to the use of a convenience sample. Additional factors such as ethnicity or position played were not considered. Since these factors could affect landing mechanics, they may have influenced the results of this study.

Future studies should focus on evaluation of factors that contribute to the changes in landing mechanics in girls during puberty such as body composition, strength, and neuromuscular control. Further understanding of these factors would help identify what should be addressed in the injury prevention programs for maturing female athletes. In addition, a long-term follow-up and investigations of ACL injury rates after injury prevention training for pubertal females are necessary.

CONCLUSION Implementation of an injury prevention training program was effective in limiting the increase in knee valgus motion and decrease in the knee flexion range of motion during landing in female basketball players during puberty. Although a significant improvement in the landing technique was not observed, affecting the factors that contribute to the risk of ACL injury might be possible in this population.

REFERENCES 1. Shea KG, Grimm NL, Ewing CK, et al. Youth sports anterior cruciate ligament and knee injury epidemiology: who is getting injured? In what sports? When? Clin Sports Med. 2011;30:691Ѹ706.

2. Powell JW, Barber-Foss KD. Sex-related injury patterns among selected high school sports. J Sports Med. 2000;28:385Ѹ391.

3. Louw QA, Manilall J, Grimmer KA, et al.

Epidemiology of knee injuries among adolescents: a systematic review. Br J Sports Med. 2008;42:2Ѹ10.

4. Renstrom P, Ljungqvist A, Arendt E, et al. Noncontact ACL injuries in female athletes: an International Olympic Committee current concepts statement. Br J Sports Med. 2008;42:394Ѹ412.

5. Lohmander LS, Englund PM, Dahl LL, et al. The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis. Am J Sports Med. 2007;35:1756Ѹ1769.

6. Myklebust G, Holm I, Maehlum S, et al. Clinical, functional, and radiologic outcome in team handball players 6 to 11 years after anterior cruciate ligament injury: a follow-up study. Am J Sports Med. 2003;31:981Ѹ989.

7. Caine DJ, Golightly YM. Osteoarthritis as an outcome of paediatric sport: an epidemiological perspective. Br J Sports Med. 2011;45:298Ѹ303.

8. Levine JW, Kiapour AM, Quatman CE, et al.

Clinically relevant injury patterns after an anterior cruciate ligament injury provide insight into injury mechanisms. Am J Sports Med. 2013;41:385Ѹ395.

9. Krosshaug T, Nakamae A, Boden BP, et al.

Mechanisms of anterior cruciate ligament injury in basketball: video analysis of 39 cases. Am J Sports Med. 2007;35:359Ѹ367.

10. Koga H, Nakamae A, Shima Y, et al. Mechanisms for noncontact anterior cruciate ligament injuries: Knee joint kinematics in 10 injury situations from female team handball and basketball. Am J sports Med. 2010;38:2218Ѹ2225.

11. Hewett TE, Myer GD, Ford KR, et al. Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: A prospective study. Am J Sports Med. 2005;33:492Ѹ501.

12. Hewett TE, Myer GD, Ford KR. Decrease in neuromuscular control about the knee with maturation in female athletes. JBJS. 2004;86A:1601Ѹ1608.

13. Schmitz RJ, Shultz SJ, Nguyen A. Dynamic valgus alignment and functional strength in males and females during maturation. J Athl Train.

2009;44:26Ѹ32.

14. Ford KR, Shapiro R, Myer GD, et al. Longitudinal sex differences during landing in knee abduction in young athletes. Med Sci Sports Exerc.

2010;42:1923Ѹ1931.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 155

15. Yu B, McClure SB, Onate JA, et al. Age and gender effects on lower extremity kinematics of youth soccer players in a stop-jump task. Am J Sports Med. 2005;33:1356Ѹ1364.

16. Myer GD, Faigenbaum AD, Ford KR, et al. When to initiate integrative neuromuscular training to reduce sports-related injuries in youth? Curr Sports Med Rep. 2011;10:155Ѹ166.

17. Myer GD, Sugimoto D, Thomas S, et al. The influence of age on the effectiveness of neuromuscular training to reduce anterior cruciate ligament injury in female athletes: A meta-analysis.

Am J Sports Med. 2012;41:203Ѹ215.

18. Myer GD, Ford KR, McLean SG, et al. The effects of plyometric versus dynamic stabilization and balance training on lower extremity biomechanics. Am J Sports Med. 2006;34:445Ѹ455.

19. Lim B, Lee YS, Kim JG, et al. Effects of sports injury prevention training on the biomechanical risk factors of anterior cruciate ligament injury in high school female basketball players. Am J Sports Med. 2009;37:1728Ѹ1734.

20. Pollard CD, Sigward SM, Ota S, et al. The influence of in-season injury prevention training on lowerextremity kinematics during landing in female soccer players. Clin J Sports Med. 2006;16:223Ѹ227.

21. Carskadon MA, Acebo C. A self-administrated rating scale for pubertal development. J Adolescent Health.

1993;14:190Ѹ195.

22. Mandelbaum BR, Silvers HJ, Watanabe DS, et al.

Effectiveness of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes. 2-year followup. Am J Sports Med. 2005;33:1003Ѹ1010.

23. Olsen OE, Myklebust G, Engebretsen L. et al.

Exercises to prevent lower limb injuries in youth sports: cluster randomized controlled trial. BMJ. 2005;330:449Ѹ452.

24. Pfeiffer RP, Shea KG, Roberts D, et al. Lack of effect of a knee ligament injury prevention program on the

25.

26.

27.

28.

29.

30.

31.

32.

33.

incidence of noncontact anterior cruciate ligament injuries. J Bone Joint Surg. 2006;88-A:1769Ѹ1774.

Hewett TE, Lindenfeld TN, Riccobene JV, et al. The effect of neuromuscular training on the incidence of knee injury in female athletes. A prospective study.

Am J Sports Med. 1999;27:699Ѹ706.

Myer GD, Ford KR, Khoury J, et al. Clinical correlates to laboratory measures for use in noncontact anterior cruciate ligament injury risk prediction algorithm. Clin Biomech. 2010;25:693Ѹ699.

Myer GD, Ford KR, Khoury J, et al. Development and validation of a clinic-based prediction tool to identify female athletes at high risk for anterior cruciate ligament injury. Am J Sports Med. 2010;38:2025Ѹ2033.

Myer GD, Ford KR, Hewett TE, et al. New method to identify athletes at high risk of ACL injury using clinic-based measurements and freeware computer analysis. Br J Sports Med. 2011;45:238Ѹ244.

Negrete RJ, Schick EA, Cooper JP. Lower-limb dominance as a possible etiologic factor in noncontact anterior cruciate ligament tears.

J Strength Cond Res. 2007;21:270-273.

Brophy R, Silvers HJ, Gonzales T, Mandelbaum BR. Gender influences: the role of leg dominance in ACL injury among soccer players. Br J Sports Med. 2010;44:694-697.

Ruedl G, Webhofer M, Helle K, et al. Leg dominance is a risk factor for noncontact anterior cruciate ligament injuries in female recreational skiers. Am J Sports Med. 2012;40:1269-1273.

Quatman CE, Ford KR, Myer GD, et al. Maturation leads to gender differences in landing force and vertical jump performance. A longitudinal study. Am J Sports Med. 2006;34:806Ѹ813.

Pantano KJ, White SC, Gilchrist LA, et al. Difference in peak knee valgus between individuals with high and low Q-angles during a single limb squat. Clin Biomech. 2005;20:966Ѹ972.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 156

IJSPT

ORIGINAL RESEARCH

EFFECTS OF HIP STRENGTHENING ON EARLY OUTCOMES FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION J. Craig Garrison, PhD, PT, SCS, ATC1 Jim Bothwell, MD2 Kiley Cohen, PT, DPT, SCS1 John Conway, MD2

ABSTRACT Purpose/Background: It is not clear whether the addition of hip strengthening exercises will improve outcomes during the early stages of ACL rehabilitation. The purpose of this study was to determine the effects of the addition of isolated hip strengthening exercises to traditional rehabilitation on early outcomes (within the first 3 months) after ACL reconstruction (ACLR).

Methods: A total of 43 subjects (18.8±6.9, 21 females, 22 males) who were in the process of rehabilitation following ACLR participated. Subjects were randomly assigned to one of two different treatment groups (1= traditional rehabilitation [NoHip], 2= traditional plus isolated hip strengthening rehabilitation [Hip]).

Assessment included the International Knee Documentation Committee (IKDC) Subjective Knee Form, Visual Analog Scale (VAS) for pain during activities of daily living, and knee extension range of motion (ROM) side to side difference taken at weeks 1, 4, 8, and 12. In addition, dynamic balance was assessed with the Y Balance Test™ at 8 and 12 weeks. A mixed model repeated measures ANOVA was performed for IKDC, VAS, and ROM. A one-way ANOVA was used to assess mean group differences for Y Balance Test – Lower Quarter (YBT-LQ) side to side difference scores at 8 and 12 weeks.

Results: There was no significant interaction for group by time across VAS (p = .463), IKDC (p = .819), or ROM (p = .513) side to side differences A significant difference was found between groups for YBT-LQ Anterior Reach (ANT) side to side difference at 12 weeks (p = .008) with the Hip group demonstrating smaller side to side reach differences than the NoHip group. No significant side to side differences were seen between groups for YBT-LQ Posteromedial (PM) or Posterolateral (PL) at 12 weeks (PM: p = .254; PL: p = .617).

Conclusions: Rehabilitation including hip strengthening exercises appears to improve sagittal plane dynamic balance at three months post ACLR as compared to traditional rehabilitation. No differences were seen between groups for pain, ROM, and subjective function during the first 3 months following ACLR. Key Terms: Anterior cruciate ligament, hip strengthening, rehabilitation Level of Evidence: Level 2b

1

Texas Health Ben Hogan Sports Medicine, Fort Worth, TX, USA 2 Texas Health Physicians Group, Fort Worth, TX, USA

CORRESPONDING AUTHOR J. Craig Garrison 800 5th Avenue, Suite 150 Fort Worth, TX 76104 Email: craiggarrison@texashealth.org

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 157

INTRODUCTION Injuries to the anterior cruciate ligament (ACL) are common in a variety of sports. Mechanisms of injury to the ACL are often non-contact in nature and involve landing, planting, cutting, and deceleration activities.15 These mechanisms may include movements in the frontal plane of motion which places the knee in a valgus loading position,3,4,6,7 thus increasing the risk of injury through an increased relative strain of the ACL.8,9 This valgus loading occurs rapidly after initial ground contact4 and weakness in the hip abductor muscles has been identified as a potential contributor to this motion.6 In healthy adults performing a single leg squat, there was a negative correlation between knee valgus and hip abduction strength.10 The greater the hip strength, the less the knee moved into a valgus position. When college athletes were tested on the single leg squat, hip external rotation strength was related to the amount of frontal plane motion at the knee.11 Likewise, when college athletes were tracked for lower extremity injury, those with greater strength in hip abduction and external rotation were less likely to be injured.12 Similarly, increased trunk displacement is greater in athletes with ACL injuries, signifying the bodyâ&#x20AC;&#x2122;s ability to use the core muscles to control the knee may be impaired.13 These results suggest that hip strength may play a role in motion at the knee that could potentially predispose an athlete to a second ACL injury.

Paterno et al14 biomechanically tested fifty-six athletes who had undergone ACL reconstruction (ACLR) and had been allowed to return to sport.Those (thirteen) who demonstrated altered hip kinetics and knee kinematics, and decreased single-limb postural stability were more likely to suffer a subsequent second ACL injury. One of the factors that predisposed these athletes to a second ACL injury involves a loss of proximal neuromuscular control in the frontal and transverse planes.14 Likewise, deficits in hip muscle torque generated during landing contributed to future ACL injury. From these findings, the authors suggested that interventions following initial ACL reconstruction that target hip strength may be beneficial in reducing the risk of second ACL injury.14 The relationship between hip strength and knee pain has been established in the literature.15-17 For the most part, this relationship has been studied in patients

with patellofemoral pain (PFP); however, it is speculated that similar mechanics may play a role in ACL injury.6 The mechanics of ACL and patellofemoral injuries are comparable.6,11 As the knee moves into valgus there is an increase in strain on the ACL8,9 and this position has successfully predicted ACL injury in female athletes.3 Weakness in gluteal muscle strength has been suggested to contribute to this position and subsequent injury.3,13,14 The fact that hip strengthening in those with PFP has played a role in functional improvements leads one to question whether these exercises may have similar effects in the ACLreconstructed population. There is a lack of current evidence for the inclusion of specific hip strengthening exercises in the post-operative rehabilitation of patients who have undergone ACLR, therefore, the purpose of this study was to determine the effects of the addition of isolated hip strengthening exercises to traditional rehabilitation on early outcomes (within the first 3 months) after ACLR. The authors hypothesized that patients who performed specific hip strengthening exercises in the early stages following ACLR would demonstrate better outcomes at 12 weeks post-operative in self-reported function, pain, ROM, and dynamic balance than those patients who did not perform hip strengthening exercises.

METHODS Forty-three participants (21 females, 22 males) volunteered for this study. Each participant was enrolled during the initial week of physical therapy following ACL reconstruction with an average starting date of 5 days post-operative. A total of 92% of the reconstructions involved the dominant limb (right) of the participants. Demographics for the participants are listed in Table 1. Inclusion criteria were 1) an isolated ACL reconstruction, 2) between the ages of 14 and 40, and 3) physically or recreationally active a minimum of three times per week. Participants were excluded from the study if there was 1) a previous ACL tear and/or reconstruction on either side, 2) an associated chondral defect requiring surgical intervention, or 3) a meniscus tear requiring a repair.

Patients gave informed consent once they were confirmed to meet the inclusion and exclusion criteria.

Child assent and parental permission were obtained for those participants who were minors at the time of the study. Once enrolled in the study, objective

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 158

Table 1. Participant demographics for the Hip and NoHip groups following anterior cruciate ligament reconstruction

measurements were taken on the participantâ&#x20AC;&#x2122;s knee and patient outcome forms were completed. The Institutional Review Board of Texas Health Resources approved the research procedures.

Participants were randomly assigned into one of two different treatment groups (1 = traditional rehabilitation [NoHip], 2 = traditional plus isolated hip strengthening rehabilitation [Hip]). All participants began their rehabilitation program on the first day of study enrollment (average of 5 days post-operative) and averaged two times per week in physical therapy for 12 weeks. Each participant was instructed in a home exercise program (HEP) to be performed a minimum of three times per week. Participants in the Hip group performed a series of hip strengthening exercises during each of their visits for a total of eight weeks (Appendix 1). Those in the NoHip group were not allowed to perform any of the hip strengthening exercises initially (Appendix 2), but were allowed to begin performing the exercises as part of their program at the 8 week mark. Between weeks 8 and 12, both groups continued to perform structured physical therapy (to include hip strengthening

exercises) two times per week with an emphasis on developing the ability to demonstrate neuromuscular control with single limb activities.

The hip strengthening exercises (Table 2) were selected based on previous electromyographical (EMG) studies that demonstrated significant gluteal muscle activation, adequate for a strengthening stimulus.18-22 The dosage for the hip strengthening exercises was gradually increased based upon the ability of the subject to perform the exercises correctly for a total of three sets of 10 repetitions. As example, if a subject could perform three sets of 10 repetitions of sidelying hip abduction without weight, then the decision was made to add between one and two pounds to the exercise as a means of progression. Because of the clinical nature of the study, the decision to progress in resistance with an exercise was made by the supervising physical therapist and in conjunction with the principal investigator.

Knee extension range of motion (ROM) side to side difference, the International Knee Documentation Subjective Knee Form (IKDC), and a Visual Analog Scale (VAS) for pain were collected at 1, 4, 8, and 12

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 159

Table 2. Electromyographical (EMG) activity of the gluteus medius and gluteus maximus expressed as % of maximum voluntary contraction (MVIC) during selected exercises, as reported in the literature

weeks post-operative. The IKDC has previously been shown to be reliable and valid across a broad patient population23 and has demonstrated both internal consistency and validity in adolescents.24 For the measurement of pain, the VAS has been shown to be reliable25 and for purposes of this study, was recorded based upon activities of daily living during the 48 hours preceding the participant’s physical therapy visit. In addition, the Y Balance Test – Lower Quarter (YBT-LQ) (side to side difference) was measured at 8 and 12 weeks post-operative. Knee extension ROM measurements were taken with a bubble goniometer while the patient was in a supine position with both knees in extension. The patient was instructed to actively tighten their quadriceps and fully straighten the knee to the best of their ability. The axis of the goniometer was placed at the center of the knee while the stationary arm was aligned through the shaft of the femur and the greater trochanter. The moving arm of the goniometer was aligned through the shaft of the fibula and pointed toward the center of the lateral malleolus. Knee extension measurements were taken by two physical therapists to ensure consistency. Prior to beginning the study, inter-rater reliability for knee extension was calculated and found to be good (ICC(2,1) = 0.88, SEM = 0.10°).

The YBT-LQ™ was measured at both 8 and 12 weeks following ACL reconstruction. Measurements were

taken in the anterior (ANT) (Figure 1), posteromedial (PM) (Figure 2), and posterolateral (PL) (Figure 3) directions on both the involved and uninvolved limbs. The participants were instructed in the YBTLQ protocol using a combination of verbal cues and demonstration.26 All participants wore shoes during testing and began on their uninvolved limb. The participants were asked to perform single limb stance on the extremity while reaching outside their base of support to push a reach indicator box along the measurement pipe. Elevation of the heel, toe or loss of balance resulting in a stepping strategy was recorded as a trial error indicating the trial should then be repeated.26 Participants were allowed at least three practice trials in the ANT, PM and PL directions prior to recording the best of three formal trials in each plane. Three trials were completed on the uninvolved limb in the ANT direction followed by three trials completed on the involved limb. This protocol was then replicated in the PM and PL directions. The maximal reach distance was recorded at the place where the most distal part of the foot reached based on the measurement pipe.26 Side-to-side limb reach differences were calculated by subtracting reach distance of the involved limb from the uninvolved limb. This measurement was used in order to establish asymmetries between the involved and uninvolved limbs during the first three months following ACLR. All balance measurements

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 160

Figure 2. Y-Balance Test-Lower Quarter, posteromedial reach direction.

Figure 1. Y-Balance Test-Lower Quarter, anterior reach direction.

were taken by two physical therapists and one athletic trainer. Reliability standards were established between the clinicians involved in each of the three directions measured, ANT (ICC2,k = .86, SEM = 3.3 cm), PM (ICC2,k = .99, SEM = 1.7 cm), and PL (ICC2,k = .95, SEM = 2.7 cm). The reproducibility of this method was found to be acceptable.

Statistical Analysis An a priori analysis with YBT-LQ Anterior reach side to side difference determined that 10 participants in each group were needed at .80 power, p < 0.05 for statistical significance. A mixed model repeated measures ANOVA was used to determine differences between IKDC, VAS, and knee extension ROM. Two one-way ANOVAs were used to calculate mean group differences for YBT-LQ at 8 and 12 weeks. All anal-

Figure 3. Y-Balance Test-Lower Quarter, posterolateral reach direction.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 161

yses were calculated using SPSS version 19.0 (Chicago, IL 60606).

RESULTS The mean number of physical therapy visits per week was not statistically different between both the Hip (1.90±.53) and NoHip. (2.1±.48) groups (p = 0.14).

There was a significant main effect for time on IKDC, VAS, and extension ROM (p < 0.001). No significant interaction was seen for IKDC (F1, 41 = .053, p = .819), VAS (F1,41 = .549, p = .463), or extension ROM (F1,41 = .434, P = .513) between groups at 1 week, 4 weeks, 8 weeks, or 12 weeks. For YBT-LQ measurements at 8 weeks, there were no significant differences between groups for ANT (p = .535), PM (p = .494), or PL (p = .265). At 12 weeks, participants in the hip strengthening group demonstrated significantly less side to side differences in the ANT direction when compared to those in the NoHip group (p = .008); however, there were no significant differences in PM (p = .254), or PL (p = .617). Table 3 outlines the group means and standard deviations for each variable across all time points.

DISCUSSION The purpose of this study was to investigate the effects of isolated hip strengthening exercises (added to a traditional rehabilitation program) on early outcomes following ACLR. The authors’ hypothesized that those in the Hip group would demonstrate better outcomes in self-reported function, pain, ROM, and dynamic balance than those who did not perform hip strengthening exercises at 12 weeks post-operative. Participants who performed hip strengthening exercises during the first eight weeks following ACLR demonstrated lower side to side YBT-LQ anterior reach differences at three months between the involved and uninvolved limbs when compared to participants who did not perform hip strengthening exercises. No differences were seen in IKDC, VAS, or knee extension ROM at 1, 4, 8 or 12 weeks between groups. Because these exercises were performed early in the rehabilitation process following ACL reconstruction, any improvements in hip strength or neuromuscular control might not have translated to less functional patient-reported outcomes (IKDC, VAS). Similarly, the exercises chosen for the study may not have provided a training stimulus great enough to elicit a change in the participant’s percep-

tion of function, pain level, or knee extension ROM. The results of this study suggest that hip strength may not be directly related to IKDC or VAS and may not play a role in the restoration of knee extension ROM. Proximal control at the pelvis and trunk is required during single limb activities.20 The hip strengthening exercises performed by the Hip group in this study have previously been shown sufficient to provide a strength training stimulus in both the gluteus medius and maximus.18,20-22 In order to reach a muscle activation threshold to produce a strengthening effect at the trunk and hip musculature, the exercise must elicit between 40% and 60% of maximum voluntary isometric contraction (MVIC).22,27 Based upon the existing evidence, the majority of hip strengthening exercises in the current study met these criteria. These results of the current investigation suggest that it is plausible there may have been an increase in strength in the Hip group that may not have been present in the NoHip group; however, the fact that the hip strength of these patients was not tested at either the beginning or at the 12 week mark precludes the conclusion of strength gains in the Hip group. Participants in this study were postoperative, so it was not possible to obtain an accurate hip strength measurement during the initial stages of physical therapy and thus baseline strength for the gluteus medius and maximus was unable to be established.

Norris et al28 previously demonstrated that the gluteus medius produces a higher normalized EMG signal in the anterior reach direction when compared to the posteromedial reach. Likewise, the action of the anterior reach is essentially a single leg squat and, as such, produces high EMG activation of the gluteus medius and maximus19,20,29 and earlier gluteus medius activity in individuals who perform a “good” squat.30 This increase in gluteal muscle activation is theorized to promote pelvic stability during single limb functional movements,31 minimize trunk collapse and valgus movement at the knee,30 and may explain why participants in the Hip group demonstrated smaller side to side reach differences in the anterior direction than the participants in the NoHip group. Furthermore, the mean side to side anterior reach difference (2.7 cm) in the Hip group

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 162

Table 3. Means and standard deviations for measurements at time points of 1 week, 4 weeks, 8 weeks, and 12 weeks between both groups

was below the 4 cm cut-off for risk of lower extremity injury in basketball players that was previously published32 while those in the NoHip group (6.1 cm) demonstrated larger differences. While this data involves post-operative ACL reconstruction participants and cannot be directly compared to healthy basketball players,32 it does provide a guideline that can be used in the clinical decision-making process.

YBT-LQ reach differences were not seen between groups at 8 weeks in any of the directions (ANT, PM, PL). Each participant in the Hip group performed hip strengthening exercises for the first eight weeks following surgery at which time the NoHip group was not allowed to begin hip strengthening. Any gains in strength that may have occurred in the Hip group during the first eight weeks are most likely related to neural adaptations from performing these exercises.33,34 While the hip strengthening exercise program may have produced high EMG activity in the gluteal muscles,18,19,21,22 the movements performed during the YBT-LQ testing require a synergy of muscles working together and could reflect efficiency of

neuromuscular coordination.33 It is possible that one of the reasons there were no differences in YBT-LQ reach between the two groups at eight weeks is that the Hip group had yet to establish an efficient neuromuscular control pattern in this complex movement despite building a foundation of hip strength in less functional exercises. Likewise, the overall total volume of exercises performed by the Hip group was greater at 12 weeks than at the 8-week mark. This increase in volume may have led to improvements in neuromuscular activation or actual strength parameters at the hip which allowed the participants in the hip strengthening group to reach outside their base of support.35 Previous research in the realm of examination of subjects with patellofemoral pain has demonstrated that weakness in the gluteal muscles may contribute to altered kinematics at the knee.15-17 Dynamic MRI demonstrates greater knee adduction and hip internal rotation in patients with patellofemoral pain.36 These altered mechanics are believed to be similar to the mechanism for ACL injuries. Biomechanical

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 163

measures of frontal plane loading in knee valgus and decreased neuromuscular control at the hip predict ACL injury in female athletes.3 Similarly, knee valgus loading and compensations at the contralateral hip are partially responsible for predicting a second ACL injury.14 As such, it would seem plausible that a rehabilitation program that addresses these altered kinematics and potential ACL risk factors through hip strengthening exercises may be important following ACLR. Those participants in our study who performed hip strengthening exercises in the early phases of rehabilitation following ACLR demonstrated less asymmetry in performance of single leg squat at three months than those who did not perform hip strengthening.

These results suggest that hip strengthening exercises help to build single leg strength and neuromuscular control and may provide a platform on which to build in the later stages of ACL rehabilitation.

Limitations The fact that gluteal muscle strength was not measured in these patients precludes a direct association between improvements in YBT-LQ anterior reach and strength in the Hip group from being made. Although it would appear that participants in the Hip group may have benefited from performing the gluteal exercises during the initial stages of the rehabilitation process, the results from the current investigation are unable to validate whether actual strength gains occurred that might have contributed to the YBT-LQ performance at 12 weeks.

All participants in this study averaged two times per week of structured physical therapy over a 12-week period; however, absolute compliance with the HEP when they were not under the supervision of the physical therapists cannot be guaranteed. Attempts were made to minimize non-compliance with participant and treating therapist education regarding the exercise programs for both groups (Hip and NoHip) in the clinic and in the HEP. Each participant was a patient within the physical therapy setting and the principal investigator was able to visit with each individual on a weekly basis and monitor the exercise programs.

CONCLUSION Isolated hip strengthening exercises may not influence early outcome measurements such as patient outcome forms, pain levels or ranges of motion, but

they may be beneficial for the development of single limb function during the first three months of a rehabilitation program following ACL reconstruction.

REFERENCES 1. Arendt EA, Agel J, Dick R. Anterior cruciate ligament injury patterns among collegiate men and women. J Athl Train. 1999;34:86-92.

2. Boden BP, Torg JS, Knowles SB, Hewett TE. Video analysis of anterior cruciate ligament injury: Abnormalities in hip and ankle kinematics.

Am J Sports Med. 2009;37:252-259.

3. Hewett TE, Myer GD, Ford KR, Heidt RS, Colosimo AJ, McLean SG, van den Bogert AJ, Paterno MV, Succop P. Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes. Am J Sports Med. 2005;33:492-501.

4. Koga H, Nakamae A, Shima Y, Iwasa J, Myklebust G, Engebretsen L, Bahr R, Krosshaug T. Mechanisms for noncontact anterior cruciate ligament injuries. Knee joint kinematics in 10 injury situations from female team handball and basketball. Am J Sports Med. 2010;38:2218-2225.

5. Krosshaug T, Slauterbeck JR, Engebretsen L, Bahr R. Biomechanical analysis of anterior cruciate ligament injury mechanisms: three-dimensional motion reconstruction from video sequences. Scand J Med Sci Sports. 2007;17:508-519.

6. Geiser CF, Oâ&#x20AC;&#x2122;Connor KM, Earl JE. Effects of isolated hip abductor fatigue on frontal plane knee mechanics. Med Sci Sports Med. 2010;42:535-545.

7. Joseph MF, Rahl M, Sheehan J, MacDougal B, Horn E, Denegar CR, Trojian TH, Anderson JM, Kraemer WJ. Timing of lower extremity frontal plane motion differs between female and male athletes during a landing task. Am J Sports Med. 2011;39:1517-1521.

8. Markolf KL, BurchďŹ eld DM, Shapiro MM, Shepard MF, Finerman GA, Slauterbeck JR. Combined knee loading states that generate high anterior cruciate ligament forces. J Orthop Res. 1995;13:930-935.

9. Quatman CE, Kiapour AM, Demetropoulos CK, Kiapour A, Wordeman SC, Levine JW, Goel VK, Hewett TE. Preferential loading of the ACL compared with the MCL during landing. A novel In Sim approach yields the multiplanar mechanism of dynamic valgus during ACL injuries. Am J Sports Med. 2013;42:177-186.

10. Claiborne TL, Armstrong CW, Gandhi V, Pincivero DM. Relationship between hip and knee strength and knee valgus during a single leg squat. J Appl Biomech. 2006;22:41-50.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 164

11. Willson JD, Ireland ML, Davis IS. Core strength and lower extremity alignment during single leg squats.

Med Sci Sports Med. 2006;38:945-952.

12. Leetun DT, Ireland ML, Willson JD, Ballantyne BT, Davis IS. Core stability measures as risk factors for lower extremity injury in athletes. Med Sci Sports Med. 2004;36:926-934.

13. Zazulak BT, Hewett TE, Reeves NP, Goldberg B, Cholewicki J. DeďŹ cits in neuromuscular control of the trunk predict knee injury risk. A prospective biomechanical-epidemiologic study. Am J Sports Med. 2007;35:1123-1130.

14. Paterno MV, Schmitt LC, Ford KR, Rauh MJ. Biomechanical measures during landing and postural stability predict second anterior cruciate ligament injury after anterior cruciate ligament reconstruction and return to sport. Am J Sports Med. 2010;38:1968-1978.

15. Fukuda TY, Rossetto FM, Magalhaes E, Bryk FF, Lucareli PR, de Almeida Aparecida Carvalho N. Short-term effects of hip abductors and lateral rotators strengthening in females with patellofemoral pain syndrome: a randomized controlled clinical trial. J Orthop Sports Phys Ther.

2010;40:736-742.

16. Earl JE, Hoch AZ. A proximal strengthening program improves pain, function, and biomechanics in women with patellofemoral pain syndrome. Am J Sports Med. 2011;39:154-163.

17. Bolgla LA, Malone TR, Umberger BR, Uhl TL. Comparison of hip and knee strength and neuromuscular activity in subjects with and without patellofemoral pain syndrome. Int J Sports Phys Ther.

2011;6:285-296.

18. Ayotte NW, Stetts DM, Keenan G, Greenway EH. Electromyographical analysis of selected lower extremity muscles during 5 unilateral weight-bearing exercises. J Orthop Sports Phys Ther. 2007;37:48-55.

19. Boren KB, Conrey C, Le Coguic J, Paprocki L, Voight M, Robinson TK. Electromyographic analysis of gluteus medius and gluteus maximus during rehabilitation exercises. Int J Sports Phys Ther.

2011;6:206-223.

20. DiStefano LJ, Blackburn JT, Marshall SW, Padua DA. Gluteal muscle activation during common therapeutic exercises. J Orthop Sports Phys Ther.

2009;39:532-540.

21. Bolgla LA, Uhl TL. Electromyographic analysis of hip rehabilitation exercises in a group of healthy subjects. J Orthop Sports Phys Ther. 2005;35:487-494.

22. Ekstrom RA, Donatelli RA, Carp KC. Electromyographic analysis of core, trunk, hip, and thigh muscles during 9 rehabilitation exercises. J Orthop Sports Phys Ther. 2007;37:754-762.

23. Higgins LD, Taylor MK, Park D, Ghodadra N, Marchant M, Pietrobon R, Cook C. Reliability and validity of the International Knee Documentation Committee (IKDC) Subjective Knee Form. Joint Bone Spine. 2007;74:594-599.

24. Schmitt LC, Paterno MV, Huang S. Validity and internal consistency of the International Knee Documentation Committee Subjective Knee Evaluation Form in children and adolescents. Am J Sports Med. 2010;38:2443-2447.

25. Bijur PE, Silver W, Gallagher EJ. Reliability of the Visual Analog Scale for measurement of acute pain.

Academic Emergency Medicine. 2001;8:1153-1157.

26. Plisky PJ, Gorman PP, Butler RJ, Kiesel KB. The reliability of an instrumented device for measuring components of the star excursion balance test. N Amer J Sports Phys Ther. 2009;4:92-99.

27. Andersen LL, Magnusson SP, Nielsen M, Haleem J, Poulsen K, Aagaard P. Neuromuscular activation in conventional therapeutic exercises and heavy resistance exercises: implications for rehabilitation.

Phys Ther. 2006;86:683-697.

28. Norris B, Trudelle-Jackson E. Hip- and thigh-muscle activation during the Star Excursion Balance Test.

J Sport Rehab. 2011;20:428-441.

29. Lubahn AJ, Kernozek TW, Tyson TL, Merkitch KW, Reutemann P, Chestnut JM. Hip muscle activation and knee frontal plane motion during weight bearing therapeutic exercises. Int J Sports Phys Ther.

2011;6:92-103.

30. Crossley KM, Zhang WJ, Schache AG, Bryant A, Cowan SM. Performance on the single-leg squat task indicates hip abductor muscle function. Am J Sports Med. 2011;39:866-873.

31. Vezina MJ, Hubley-Kozey C. Muscle activation in therapeutic exercises to improve trunk stability. Arch Phys Med Rehabil. 2000;81:1370-1379.

32. Plisky PJ, Rauh MJ, Kaminski TW, Underwood FB. Star Excursion Balance Test as a predictor of lower extremity injury in high school basketball players.

J Orthop Sports Phys Ther. 2006;36:911-919.

33. Carroll TJ, Riek S, Carson RG. Neural adaptations to resistance training. Sports Med. 2001;31:829-840.

34. McCarthy JP, Pozniak MA, Agre JC. Neuromuscular adaptations to concurrent strength and endurance training. Med Sci Sports Exerc. 2002;34:511-519.

35. Filipia A, Byrnes R, Paterno MV, Myer GD, Hewett TE. Neuromuscular training improves performance on the Star Excursion Balance Test in young female athletes. J Orthop Sports Phys Ther. 2010;40:551-558.

36. Souza RB, Draper CE, Fredericson M, Powers CM. Femur rotation and patellofemoral joint kinematics: a weight-bearing magnetic resonance imaging analysis. J Orthop Sports Phys Ther. 2010;40:277-285.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 165

Appendix 1. ACL Reconstruction Hip Strengthening Rehabilitation Program

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 166

Appendix 2. ACL Reconstruction NoHip Strengthening Rehabilitation Program

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 167

IJSPT

ORIGINAL RESEARCH

ASSOCIATIONS BETWEEN KNEE EXTENSOR POWER AND FUNCTIONAL PERFORMANCE IN PATIENTS AFTER TOTAL KNEE ARTHROPLASTY AND NORMAL CONTROLS WITHOUT KNEE PAIN Adam R. Marmon, PhD1 Barry I. Milcarek, PhD1 Lynn Snyder-Mackler, PT, ScD1

ABSTRACT Purpose/Background: Deficits in functional abilities persist after total knee arthroplasty (TKA), while static measures of knee extensor strength (e.g. isometric contractions) are related to functional performance, little is known about the associations between functional ability and dynamic knee extensor strength (e.g. power). With the growing rate of these procedures, in a progressively younger and more active cohort, a better understanding of the functional importance of dynamic strength (muscle power) is needed. The purpose of this study was to examine the associations between functional performance and peak knee extensor power (isokinetic and isotonic measures) from patients after unilateral TKA. Design: Cross-sectional, controlled laboratory study, with correlation and regression analyses.

Setting: Institutional clinic and research laboratory.

Participants: Patients 6 months after TKA (N=24, 12 men and women), most of whom were mildly to very active. A normal control group without knee pain (CON; N=22, 10 men and 12 women) was also assessed for comparison.

Main Outcome Measures: Static and dynamic strength measures were assessed during normalized voluntary isometric contractions (NMVIC), isokinetic contractions at three velocities (60, 90, and 120 deg/s), and isotonic contractions against three body weight normalized resistances (20, 30 and 40% BW). Functional performance was assessed using the timed up-and-go (TUG), stair climbing test (SCT), and 6- minute walk (6MW). Analyses of the relationships between functional performance measures and peak knee extensor NMVIC and power were performed. Regression analyses predicting functional performance from power were also performed after controlling for NMVIC. Results: Peak power across isokinetic velocities, isotonic resistances, and NMVICs were correlated with the functional performance measures for the TKA group. Unlike the TKA group, functional performance was not significantly associated with peak power across all isokinetic velocities and isotonic resistances (e.g no significant associations between peak isotonic power and 6MW distance). In the TKA group, inclusion of the isotonic power against 30% BW, after controlling for NMVIC, improved the predictability of all three functional performance tests; TUG (p= 0.022), SCT (p=0.006), and 6MW (p=0.001).

Conclusions: Measurements of knee extensor power may be a useful tool for clinicians when assessing and setting milestones during rehabilitation.

Level of Evidence: Prospective cohort study, level II. Key words: Dynamic strength, knee replacement, outcome assessment

1

University of Delaware, Newark DE, USA

Acknowledgements of ďŹ nancial support We would like to thank the participants for their time. We would also like to thank Liza Walker and the Delaware Rehabilitation Instituteâ&#x20AC;&#x2122;s Clinical Research Core for their support, as well as the graduate and undergraduate students and clinicians who helped collect and process the data; Ali Alnahdi, Portia Flowers, Federico Pozzi, Sumayah Abujaber, Kristen Lockwood, Rebecca Curran, Andrew Miller, and Alyssa Reyes. Funding for this project was provided the United States National Institutes of Health (F32 AR060684-02; P20 RR016458-10; P20RR01645808S3; P30 GM103333-02; U54 GM104941-01A1; K12 HD055931)

The study was approved by the University of Delaware Human Subjects Review Board.

CORRESPONDING AUTHOR Adam Rubin Marmon 301 McKinly Lab University of Delaware Newark, DE 19716 USA Phone: 1-302-831-6460 Email: marmon@udel.edu

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 168

INTRODUCTION Total knee arthroplasty (TKA) is a common procedure used for the treatment of end-stage knee osteoarthritis (OA). The frequency of the TKA procedure is increasing, with over 650,000 procedures performed in the US in 20101 and nearly 3.5 million expected by the year 2030.2 Most patients choose to undergo TKA in order to reduce their pain and recover functional abilities.3,4 Considering the high rate of TKA procedures, it is imperative that clinicians be capable of obtaining a comprehensive neuromuscular assessment and providing interventions for patients that lead to recovery of functional abilities in order for them to maintain their functional independence.

Effectiveness of rehabilitation is typically assessed through a combination of self reports (e.g. WOMAC, LEAP),5 joint range of motion,6 and muscle strength assessments.7â&#x20AC;&#x201C;12 Resolving pain and deficits in range of motion are important and appropriate focuses for the initial stages of recovery after TKA, but these measures do not provide enough insight into the long-term effects of treatment. Although pain is reduced and range of motion is improved after TKA, often, functional limitations persist 6 months13 to one year14 after surgery. Quadriceps strength has been shown to play an important role in mediating recovery of functional abilities for patients after TKA.9 The functional importance of quadriceps strength was further supported by the findings of a clinical trial that incorporated a progressive strength training intervention aimed at resolving quadriceps weakness after TKA.10 The participants in the progressive strength training intervention significantly improved their isometric strength, which led to significantly better improvements in functional ability compared to standard of care, which focused on resolving pain, improving range of motion, and returning to functional ambulation.10 However, there were no assessments of dynamic strength and despite improvements shortly after TKA, longterm functional deficits, such as distance walked in six minutes, persisted. These persistent deficits in functional ability suggest that the current battery of clinical tests for assessing and tracking treatment efficacy in patients after TKA does not fully capture the modifiable neuromuscular factors responsible for functional impairments.

Clinically, impairment based measures are used to develop treatments and to set goals that will lead to better function. Current assessments tools lack the ability to fully capture the factors limiting long-term recovery. While knee extensor strength is an impairment-based measure that is associated with functional performance, it is typically assessed using static, isometric contractions,13,15,16 whereas performance-based measures are dynamic, requiring knee extensor activity across a broad range of joint angles and contraction types. An alternative approach to better describe the functional importance of quadriceps strength would be to assess the neuromuscular parameters required during activities of daily living.17 For example, when rising from a chair, the extensors need to generate sufficient joint torques, but do so within the temporal constraints of the task.

Muscle power, the product of the joint torque and the velocity of contraction, may provide the missing link that offers insight into neuromuscular factors responsible for the persistent deficits in lower extremity functional ability in patients who undergo TKA. Patients who undergo TKA often exhibit asymmetries in peak isometric knee extensor torque between the operated and contralateral limbs, which has been shown to persist 6 months7 and up to one year18 after surgery. Between limb asymmetries also exist for quadriceps rate of force development and are larger than for isometric strength in patients after TKA.7 Additionally, movement velocity (e.g. knee extension velocity) is often reduced in patients after TKA.17,19 As reductions in muscle power are known to occur more rapidly than isometric force reductions in older adults,11,20,21 it is plausible that power reductions could be accelerated in patients after TKA. Therefore, a better understanding of the relationship between knee extensor power generating capacity and functional performance measures in patients after TKA may highlight an area of muscle function not typically considered when assessing and treating patients after TKA. Muscle power, and its relation to functional ability, is dependent upon both the speed of contraction and magnitude of the resistance. For example, in older populations, lower intensity contractions, using relatively light resistances (e.g. 40% of maximum

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 169

strength) explained more variance in gait speed than more moderate intensity contractions (e.g. 70% of maximum strength).23 Alternatively, contractions against larger resistance (e.g. 90% of maximum), explained more variance in performance of a sit-to stand task than contractions against lighter resistances (e.g. 40% of maximum).24 Therefore, a comprehensive assessment of muscle power that could control velocity and resistance, independently, would be ideal. Isokinetic contractions, conducted over a range of functionally relevant joint velocities, can be used to control velocity when assessing power. Isotonic contractions can be used to control resistance. However, isotonic contractions for assessing power are typically conducted by standardizing resistance to the subject’s maximal strength.20,21,23–26 As strength deficits are common in patients after TKA, standardizing isotonic resistances based on strength is not ideal for normalizing isotonic resistances. Alternatively, standardizing isotonic resistance to body weight may be a more appropriate means of normalization and more functionally relevant, as individuals need to move their own body while performing activities of daily living.

The purpose of this study was to examine the functional significance of knee extensor power in patients following TKA. The authors hypothesized that peak knee extensor power, produced across isokinetic velocities and isotonic resistances (normalized to body weight) would be significantly correlated with performance in lower extremity functional tests. To determine if power plays a larger role in patients with weakened quadriceps (after TKA), the strength of the relationship between peak knee extensor power and functional abilities in normal control subjects without knee pain was also investigated.

The authors hypothesized that the strength of the association between knee extensor power and functional performance would be stronger for patients who had undergone TKA compared to a group of control subjects without knee pain. Finally, the authors hypothesized that dynamic measures of strength (e.g. power) would improve the predictability of functional performance in patients after TKA, beyond that of static measures of strength, thereby providing additional insight on the role of muscle function and functional ability.

METHODS Subjects Twenty-four patients, 6 months after undergoing primary unilateral total knee arthroplasty (TKA), and a group of controls without knee pain (CON; N=22) were enrolled in this study (Table 1). Subjects’ activity levels ranged from inactive to very active before and after surgery. Patients were either referred to the study by their orthopedic surgeon or recruited through flyers and advertisements at physical therapy clinics and in public classifieds. The CON group was recruited through flyers, advertisements, and word of mouth. The CON subjects were not directly matched to the TKA group, but were compared for descriptive characteristics (Table 1). The primary exclusion criteria for patients included previous surgery joint replacement surgery or surgeries to other lower extremity joints and pain >4 out of 10 in their contralateral knee. All subjects were also excluded if they had uncontrolled hypertension, musculoskeletal conditions of the lower extremity or back that might alter their functional abilities (self-reported and defined as affected their ability to walk for 6 minutes or climb a flight of stairs), neurologic impairments, decreased sensation in the legs or feet, if they were receiving treatment for cancer at time of testing, or a body mass index >50. The same proportion of left and right surgical limbs for the patient group was used to provide the same laterality in the control group for the analysis. Additional exclusion criteria for the control group included prior lower extremity surgery or pain in either knee >4 out of 10. The study was approved by the University of Delaware’s Table 1. Descriptive Statistics.

Sex (men/women)

TKA (N=24)

CON (N=18)

12 / 12

10 / 12

p-value

Age (years)

68.2 ± 9.4

68.5 ± 8.0

0.925

Height (m)

1.70 ± 0.08

1.67 ± 0.09

0.312

Mass (kg)

91.2 ± 21.2

73.6 ± 15.7

0.003

BMI (kg/m )

31.4 ± 6.1

26.2 ± 3.7

0.001

TUG (s)

8.4 ± 2.0

6.2 ± 1.2

<0.001

14.3 ± 5.9

10.0 ± 2.1

0.002

553.4 ± 120.8

641 ± 84.5

0.006

2

SCT (s) 6MW (m)

TKA = total knee arthroplasty group, CON= normal control group, BMI= body mass index, TUG= Time Up-and-Go, SCT= Stair Climbing Test, and 6MW= 6-minute walk test.

Significant group differences are bolded.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 170

Human Subjects Review Board and all participants signed an informed consent.

Testing Procedure Functional Performance Functional performance was assessed for all subjects first using the timed up-and-go (TUG), followed by the stair climbing (SCT), and then the 6-minute walk (6MW) tests. The TUG measures the time it takes a subject to rise from a seated position in a chair, walk three meters, and return to the seating position of the same chair. The average time from two trials was used in the analysis. The TUG has previously been shown to have high intra- and inter- rater reliability.27,28 The SCT measures the time it takes for a subject to ascend and descend 12 stairs, and has been shown to have good reliability.29 The average time from two attempts is used in the analysis. The 6MW is a reliable measure of physical endurance.29,30 The instructions given to the subjects for all three of these tests were to perform each test as quickly and safely as possible.

Isometric Strength Knee extensor strength was quantified bilaterally during isometric, isokinetic, and isotonic contractions on a KinCOM electromechanical dynamometer (Chattanooga Corporation, Chattanooga, TN).

For testing, participants were seated on the KinCOM with the hip flexed to 80 degrees. The axis of rotation of the arm of the dynamometer was aligned with the knee joint, which was flexed to 75 degrees. The force transducer was positioned 2 fingers above the lateral malleolus and the lever arm was recorded.

Force data were multiplied by the lever arm, the distance from the axis of rotation to the center of the force transducer, in order to convert to torque.

Maximal voluntary isometric contractions, normalized to body mass (NMVIC) were performed first.

Warm-up contractions were performed by asking the subject to contract to approximately 50, 75 and 100% of maximal effort. Subjects were then instructed to maximally extend the knee against the restraint.

Strong verbal encouragement was provided with the greatest value from 2-3 contractions taken as the maximum, a third contraction was only performed if the first two contractions had greater than 5% difference.

Isokinetic and Isotonic Strength For the isokinetic and isotonic contractions, subjects were instructed to straighten their knee, “as hard and as fast as possible.” Each contraction was completed through 50 degrees of motion, from 80 to 30 degrees of flexion. This range was chosen as patients after TKA are often unable to fully extend the knee and flexion range is often limited. The investigator provided strong verbal encouragement for each contraction. Each participant attempted to complete the panel of isokinetic and isotonic contractions for each limb. Three isokinetic contractions were attempted for each of three velocities (60, 90, and 120 deg/s).

Three isotonic contractions were also attempted for each of three resistances. Three resistances were determined as a proportion of the subject’s inertial body weight (BW), by converting mass to newtons (kg * 9.81 m/s2). The study was initiated with the three resistances being 30, 40, and 50% BW (N=2); however, after some of the patients who underwent TKA were unable to move the 50% BW resistance, it was replaced with a 20% BW resistance. Two subjects completed the testing against the initial resistance levels. Irrespective of the pilot assessment for appropriate resistances and the early adjustment to lighten the resistances, profound weakness by a total of six subjects in the TKA group precluded them from performing all trials, and as described later, this same weakness also occurred in the some of the non-operative limbs. The test order was randomized by limb, then by type of contraction, and then within contraction type (e.g. velocity and resistance). A total of 18 dynamic contractions (3 trials for each of 3 velocities and 3 trials for each of 3 resistances) were attempted by each participant for each limb. Subjects were given at least one-minute rest between contractions and offered additional rest as needed.

For each power contraction, time series curves for force, joint angle, and angular velocity were recorded at a rate of 1000 Hz. All forces were gravity corrected in post processing. The force of the relaxed limb at full extension (limb weight at full extension) was derived from the force measured on the transducer when positioned at the end range of motion (30 degrees of flexion), because many patients six months after TKA are unable to fully extend the knee. The estimated mass of the limb at full extension was adjusted to account for the weight of the limb at any given

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 171

angle (limb weight at full extension* COS (Θ), where Θ = joint angle at a given time point) and added to the force at that joint angle. Gravity corrected forces were converted to torque using the lever arm. Power (W) was calculated as the product of torque and angular velocity. The peak power for each trial was determined, with the peak power for each limb at each isokinetic velocity and isotonic resistance used in the analyses. Isokinetic power measures were normalized to body mass and used for analysis. Absolute isotonic power was used for analysis, as the resistances were standardized by body mass.

Statistical Analyses Independent t-tests were performed to compare subject characteristics and functional performance measures between the TKA and CON groups. If Levene’s Test for Equality of Variance indicated significantly different variance between the two groups, the level of significance with equal variances not assumed is reported.

Missing observations for the isotonic data occurred because of the adjustment in resistance levels mentioned above and muscle weakness that prevented some subjects from performing contractions against the higher resistances. A modified Hotdeck imputation31 was performed to account for these missing observations as follows: Each subject’s average change in power between each pair of isotonic resistances was calculated. The average change between each resistance pair was calculated for the group and used to adjust the last observation for any subject with a missing observation. The adjusted value was then used to replace the missing observation.

The acquired data and the data after the Hotdeck imputation for the subjects in the TKA group were compared using independent samples t-tests between means for each of the isotonic resistances. Pearson correlations coefficients were calculated to determine the associations between the three functional performance measures (TUG, SCT, 6MW) and the six power measures (isokinetic at three speeds and isotonic at three resistances) for the TKA and CON groups separately. The correlation coefficients generated for the TKA and CON groups were converted to z-scores and compared using independent t-tests to determine if the correlations coefficients between

function and strength were equal between groups.32,33 Hierarchical regression analyses for the TKA group were then performed, with NMVIC entered first, followed by all six of the power measures together, to determine which, if any, measures of power significantly improved the predictability of performance in each of the three functional tests. The level of significance was set at 0.05.

RESULTS All patients in the TKA group were able to complete the isometric (MVIC) and isokinetic contractions across the three velocities (N=24). The Hotdeck adjustment was used to estimate peak power for those whose weakness precluded them from moving resistances of 40% BW (3 surgical limbs and for 3 contralateral limbs) and 30% BW (1 surgical limb and 1 contralateral limb). The Hotdeck adjustment was also used to estimate power against 20% BW for the two subjects tested prior the protocol adjustment. Due to profound weakness, one subject was unable to complete the isotonic contractions against any of the three resistances with the surgical limb, therefore the Hotdeck adjustment was unable to be completed and the analyses using the isotonic data were performed without this subject (N=23).

All strength measures, NMVIC and peak power produced during across isokinetic and isotonic contractions, were significantly correlated with performance in all three functional performance measures for the TKA group, with r-values ranging from 0.436 to 0.710 (Table 2). Not all strength measures were significantly correlated with all functional performance measures for the CON group, with r-values ranging from 0.089 to 0.702 (Table 2). For the TKA group, the TUG was most related to NMVIC, but both the SCT and 6MW were most related to peak isotonic power at 30% BW. The correlation coefficients obtained between strength and functional performance measures were only significantly stronger in the TKA compared to the CON group for 6MW and isotonic contractions at 20 and 30% BW. Group Differences No differences existed between groups for age and height, but the TKA group was significantly heavier and had larger BMI than the CON group (Table 1). The TKA group performed significantly worse than the

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 172

Table 2. Pearson’s correlation coefficients for the patients between Functional Performance Measures and both static (NMVIC) and dynamic (Peak Power during Isokinetic and Isotonic contractions) measures of strength for patients 6 months after total knee arthroplasty (TKA) and for a sample of normal controls (CON).

TUG

SCT

6MW

TUG

SCT

Isokinetic Power

-.639†

-.575**

.436*

-.533*

-.492*

.570*

___TKA Group (N=24)____ ____CON Group (N=22)___

60 deg/s

-.470*

-.511*

.543**

-.537**

-.526*

.461*

90 deg/s

-.470*

-.481*

.563**

-.702†

-.637†

.495*

120 deg/s

-.507*

-.513**

.592**

-.566**

-.601**

.419

Isotonic Power

___TKA Group (N=23)____ ____CON Group (N=22)___

20% BW

-.566**

-.635†

30% BW

-.599**

-.657†

40% BW

-.528**

-.624†

.671†

TUG

6MW

___TKA Group (N=24) ___ ____CON Group (N=22) ___ NMVIC

Table 3. Comparison of the correlations coefficients produced for the functional performance and both static (NMVIC) and dynamic (Isokinetic and Isotonic contractions) measures of strength between the patients in the total knee arthroplasty (TKA) and healthy control (CON) groups.

-.420

-.432*

.130

.710†

-.564*

-.450*

.135

.530**

-.618**

-.489*

.089

* p≤0.05, ** p≤0.01, † p≤0.001 The data for peak Isotonic Power are reported for after the Hotdeck imputation.

NMVIC= Normalized voluntary isometric contractions; Isokinetic contractions at 3 speeds (60, 90, and 120 deg/s) and Isotonic Power= isotonic contractions against 3 body weight normalized resistances (20, 30, and 40% BW), TUG= Time Up-and-Go, SCT= Stair Climbing Test, and 6MW= 6-minute walk test.

CON group (Table 1) for all three performance tests; TUG (p<.001), SCT (p=.002), and 6MW (p=0.006).

No statistical differences were found with the TKA group when comparing the acquired peak isotonic power data and the peak isotonic power data after the modified Hotdeck imputation for any of the isotonic resistance levels (p>0.573).

Associations between Strength and Function The relationships between the three functional performance measures and MVIC, peak isokinetic power, and peak isotonic power are presented in Table 2.

It is important to note that the SCT and TUG are time-based measures where a better performance is equivalent to a lower time, therefore the negative correlations coefficients with peak power indicate greater power is related to better SCT and TUG performance.

Conversely, 6MW is the distance covered, such that greater distance indicates better performance, the positive correlations with peak power indicate the greater the power the better the 6MW distance.

Comparison of the correlations coefficients between measures of power and functional performance for the TKA and CON group are presented in Table 3.

NMVIC

SCT

6MW

z

p

z

p

z

p

-0.512

0.609

-0.367

0.713

-0.569

0.569

Isokinetic Power 60 deg/s

0.284

0.777

0.065

0.948

0.347

0.729

90 deg/s

1.141

0.254

0.723

0.470

0.299

0.765

120 deg/s

0.262

0.793

0.404

0.686

0.740

0.459

Isotonic Power 20% BW

-0.047

0.481

-0.897

0.370

2.013

0.044

30% BW

-0.155

0.438

-0.945

0.345

2.127

0.033

40% BW

0.393

0.347

-0.614

0.539

1.268

0.205

NMVIC= Normalized voluntary isometric contractions; Isokinetic contractions at 3 speeds (60, 90, and 120 deg/s) and Isotonic Power= isotonic contractions against 3 body weight normalized resistances (20, 30, and 40% BW), TUG= Time Up-and-Go, SCT= Stair Climbing Test, and 6MW= 6-minute walk test.

Significant group differences are bolded.

Multivariate correlation analyses indicate that after controlling for NMVIC, peak isotonic power produced against a 30% BW resistance significantly improved the predictability of all three functional performance measures for the TKA group (e.g. knowing peak isotonic power at 30%BW allows for more accurate predictions of performance measures (Table 4). Moreover, the model predicting 6MW was not affected by the removal of the NMVIC, such that peak isotonic power at 30% BW was the only factor needed.

DISCUSSION The findings of the current study demonstrate that measures of peak knee extensor power across isokinetic velocities and isotonic resistances are associated with functional performance tests for patients, 6-months after TKA. Individuals without knee pain (CON) exhibited similar relations between power and functional performance, but not across all velocities and resistances. The authors also hypothesized that the associations between power and function would be stronger for the TKA group compared to the CON group. It was determined that for the isotonic contractions, the TKA group exhibited significantly stronger associations with functional performance than the CON group when predicting the 6MW. Conversely, the CON group exhibited stronger, albeit not sig-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 173

Table 4. Output from regression analyses predicting Functional Performance of patients in the TKA group for the three functional tasks (N=23).

Task

R

R2

R2 Change

F Change

Significance of F Change

NMVIC + 30% BW

.635 .738

.404 .545

.404 .141

14.214 6.200

.001 .022

NMVIC + 30% BW

.594 .750

.353 .562

.353 .209

11.450 9.561

.003 .006

NMVIC + 30%BW NMVIC removed

.428 .727 .710

.183 .528 .504

.183 .345 -.024

4.704 14.641 1.036

.042 .001 .321

Model

TUG

SCT

6MW

NMVIC= normalized maximal voluntary isometric contraction, TUG= timed up-and-go, SCT= stair climbing test, 6MW= 6-minute walk, 30% BW = peak isotonic power with the 30% body weight resistance.

Significant improvements in regression models are bolded.

nificantly different, associations between isokinetic power and functional performance than the TKA group. Finally, the authors hypothesized and demonstrated that including dynamic measures of strength, such as power, improved predictability of functional performance over assessments of isometric strength alone.

Both the TKA and CON groups exhibited negative correlations between the timed functional assessments (TUG and SCT) and the strength measures, indicating that individuals who produced lower levels of peak power needed more time to complete the tests. Alternatively, positive associations were observed for both groups between the measures of muscle power and 6MW distance, such that those who produced high peak power walked further during the test. The strength of the associations between power and function were generally higher with the isotonic assessments in the TKA group than the isokinetic measures, albeit not statistically different. This may be attributed to the fact that the isotonic resistances were determined as a proportion of each individualâ&#x20AC;&#x2122;s body weight. The stronger relationships demonstrated in this aspect of the study suggest that strength levels relative to body weight need to be achieved for the likelihood of success in functional performance in patients after TKA. Not all clinicians will have access to the more advanced and expensive dynamometry used in this study, but these findings indicate that the ability to powerfully

extend the knee against 30% of body weight, which could easily be assessed on standard knee extension machine, and can be a good clinical goal for this patient population.

Quadriceps strength is often assessed clinically with static, maximal isometric contractions. The improved prediction of functional performance when combining isometric strength and dynamic, power measures highlights the clinical importance of muscle power.

In healthy older adults, deficits in dynamic muscle strength (e.g. power) can go above and beyond the deficits in isometric strength,34 suggesting that assessing both measures may provide better insight into the neuromuscular factors affecting functional ability. Particularly for those whose active lifestyles may have been limited prior to surgery by pain, but who strive to return to more active lifestyles after surgery when pain is resolved. Measures of muscle power in patients after TKA are necessary to gain a more comprehensive understanding of the factors that contribute to the persistent functional deficits.4,35,36 The isometric strength and power measures had similar associations with the functional performance measures, but the complementary nature of these measures indicates that different components of muscle function are captured by these two different measures of strength. While isometric strength is a reflection of the forces a muscle can produce, muscle power reflects the ability to generate muscle force over time, which is imperative for completing

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 174

activities of daily living, such as climbing stairs or rising form a chair. Future work should focus on identifying how the different measures of strength are related to biomechanical variables to better understand how strength is related to functional ability. As functional performance measures involve dynamic muscle activity, it is not surprising that the dynamic measures of strength are related to these functional measures.

The physiological mechanism most likely responsible for the reduced power of older adults was the reduction in contraction speed.34,35 This suggests that while the muscle may be capable of producing a given force, it is the ability to develop the force quickly that may be impaired. Previous work has demonstrated that a training intervention for older, mobility limited individuals that focused on speed of movement led to improvements in functional ability.26 With the associations between power and function observed here, future studies on strength training interventions after TKA should consider incorporating a focus on contraction speed, which may lead to clinical outcomes of functional ability.

The findings of the current study support previous work that showed measures of leg extensor power was associated with functional performance in patients after TKA.37 The associations between power and function in the work by Aalund and colleagues appear to be stronger (r=0.740 for power and 30-second chair stand, and 0.820 for power and 10-meter fast walk speed) than those found here (ranging from 0.470-0.710) and were consistently greater than the relations between maximal isometric strength and function. These differences can be attributed to differences in methodology, including the choice of power assessment, the functional performance measures, and the time when assessments were made. First, knee extensor power, a single joint, open-chain task where the knee extensors were isolated was assessed in the current study. Aalund et al assessed leg extensor power using a leg press, which is a closed-chain, multi-joint task.37 The leg press movement does not directly assess knee extensor weakness as the multijoint task allows subjects to utilize varied neuromuscular strategies in order to compensate for quadriceps weakness. Considering the substantial weakness and atrophy of the quadriceps in patients prior to TKA

and up to one year following TKA, assessments of the knee extensors using an open-chain test provides a more focused metric for clinicians to utilize in rehabilitation than the multi-joint leg press. Therefore, use of the leg press to assess strength in clinical populations with known quadriceps weakness8,9,11,38,39 may mask the extent of quadriceps dysfunction. Future work should determine if, in fact, using the leg press for assessment of patients after TKA underestimates the deficits in quadriceps strength. Differences in the chosen functional performance measures also differentiate the current findings from previous work.

Aalund et al. measured the 30-second Chair Stand test and 10 meter fast speed walking test, whereas the TUG, SCT, and 6MW were used in the current study.37 These different functional performance measures limit the ability to directly compare the results. Finally, the differences in timing of assessments are quite substantial. Aalund et al conducted assessments at 4 weeks post TKA compared to the subjects in the current study who were all at least 6 months post TKA. The current results, where the assessments were performed after treatment when plateaus in strength are observed,40 likely provides greater long-term insight into how muscle impairments that remain after treatment are related to the persistent functional impairments.14,35,36 In a busy clinic, where time is limited, it is hard to suggest that isometric strength data should not continue to be collected. However, the results of the current study suggest that if time and equipment permit, the addition of a power assessment against 30%BW would provide the best overall prediction of functional performance. In lieu of the ability to assess either isometric contractions or power, clinicians might consider assessing a patientâ&#x20AC;&#x2122;s dynamic strength with a body-weight normalized metric, such as normalizing an individualâ&#x20AC;&#x2122;s one-repetition maximum to the individualâ&#x20AC;&#x2122;s weight. Based on the current findings, a practical and clinically meaningful target for recovery from TKA should be the ability to complete an isotonic contraction against 30% of body weight. Once the ability to complete a contraction against 30% body weight is achieved, focus on improving the speed of contraction, and therefore power generated during the contraction, may lead to further improvements in functional performance.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 175

Study Limitations There are some limitations with this study, including the use of the modified Hotdeck imputation to estimate values for missing observations. However, the primary reason for completing the Hotdeck imputation was to provide an estimate of muscle power for subjects that were too weak to complete the task against the heavier resistance levels. In this study, the resistance levels were standardized to body weight in order to assess power during functionally relevant loads. Considering the previously established importance of quadriceps strength for functional ability, removal of the subjects unable to move the heavier of the isotonic loads would have constituted removing individuals with strength deficits commonly observed in this population. Thus, the authors feel that the modified Hotdeck imputation was a conservative method of estimating performance, had the subjects been strong enough to complete tests at all resistance levels. Additionally, the authors evaluated the relationships between power and function in the current data, prior to the Hotdeck adjustment, and similar relationships were present. Another limitation is that only knee extensor power was assessed and not knee flexion or overall leg extension power.

Future work should systematically assess the differential contributions to functional ability of dynamic extensor strength for the entire limb to a focused assessment on the knee extensors along with the role of knee flexion strength. Additionally, while the present work demonstrates the existence of relationships between factors, a future interventional study is needed to more directly address the relationships between knee extensor power and functional abilities in patients after TKA. CONCLUSION The results of this study demonstrate that dynamic strength measures, like the assessment of muscle power, can provide important insight into how quadriceps weakness relates to functional performance.

Performing powerful knee extension contractions, particularly against a resistance normalized to a patient’s weight (e.g. 30%BW), may provide better insight into functional ability than isometric strength alone. Future studies need to be conducted to determine if interventions aimed at improving muscle power, in patients after TKA, can lead to greater

improvements in functional ability than improvements absolute force production alone.

REFERENCES 1. National Center for Health Statistics. U.S. Center for Disease 2010 National statistics - principal procedure only Outcomes by 81.54 Total Knee Replacement.

2013.

2. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030.

J Bone and Joint Surg Am. 2007;89(4):780–5.

3. König A, Walther M, Kirschner S, Gohlke F. Balance sheets of knee and functional scores 5 years after total knee arthroplasty for osteoarthritis: a source for patient information. J Arthroplasty. 2000;15(3): 289–94.

4. Gonzalez Sáenz de Tejada M, Escobar A, Herrera C, García L, Aizpuru F, Sarasqueta C. Patient expectations and health-related quality of life outcomes following total joint replacement. Value Health. 2010;13(4):447–54.

5. Finch E, Walsh M, Thomas SG, Woodhouse LJ. Functional ability perceived by individuals following total knee arthroplasty compared to age-matched individuals without knee disability. J Orthop Sport Phys. 1998;27(4):255–63.

6. Bruun-Olsen V, Heiberg KE, Mengshoel AM. Continuous passive motion as an adjunct to active exercises in early rehabilitation following total knee arthroplasty - a randomized controlled trial. Disabil Rehab. 2009;31(4):277–83.

7. Maffiuletti N, Bizzini M, Widler K, Munzinger U. Asymmetry in quadriceps rate of force development as a functional outcome measure in TKA. Clin Orthop. 2010;468(1):191–8.

8. Mizner RL, Stevens JE, Snyder-Mackler L. Voluntary activation and decreased force production of the quadriceps femoris muscle after total knee arthroplasty. Phys Ther. 2003;83(4):359–65.

9. Mizner RL, Petterson SC, Stevens JE, Vandenborne K, Snyder-Mackler L. Early quadriceps strength loss after total knee arthroplasty. The contributions of muscle atrophy and failure of voluntary muscle activation. J Bone Joint Surg Am. 2005;87(5):1047–53.

10. Petterson SC, Mizner RL, Stevens JE, Raisis L, Bodenstab A, Newcomb W, Snyder-Mackler L. Improved function from progressive strengthening interventions after total knee arthroplasty: a randomized clinical trial with an imbedded prospective cohort. Arthritis Rheum. 2009;61(2): 174–83.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 176

11. Silva M, Shepherd EF, Jackson WO, Pratt J a, McClung CD, Schmalzried TP. Knee strength after total knee arthroplasty. J Arthroplasty.

2003;18(5):605–611.

12. Yoshida Y, Mizner RL, Ramsey DK, Snyder-Mackler L. Examining outcomes from total knee arthroplasty and the relationship between quadriceps strength and knee function over time. Clin Biomech (Bristol, Avon). 2008;23(3):320–8.

24.

25.

13. Bade MJ, Kohrt WM, Stevens-Lapsley JE. Outcomes before and after total knee arthroplasty compared to healthy adults. J Orthop Sports Phys Ther.

2010;40(9):559–67.

gait speed in disabled older men and women.

Gerontol A Biol Sci Med Sci. 2004;59(11):1200–6.

Puthoff ML, Nielsen DH. Relationships among impairments in lower-extremity strength and power, functional limitations, and disability in older adults.

Phys Ther. 2007;87(10):1334–47.

Reid KF, Doros G, Clark DJ, Patten C, Carabello RJ, Cloutier GJ, Phillips EM, Krivickas LS, Frontera WR, Fielding RA. Muscle power failure in mobilitylimited older adults: preserved single Wber function despite lower whole muscle size, quality and rate of neuromuscular activation. Eur J Appl Physiol.

2012;112(6):2289–2301.

Reid KF, Callahan DM, Carabello RJ, Phillips EM, Frontera WR, Fielding RA. Lower extremity power training in elderly subjects with mobility limitations: a randomized controlled trial. Aging Clin Exp Res. 2008;20(4):337–43.

Podsiadlo D, Richardson S. The timed “Up & Go”: a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc. 1991;39(2):142–8.

14. Walsh M, Woodhouse LJ, Thomas SG, Finch E. Physical impairments and functional limitations: a comparison of individuals 1 year after total knee arthroplasty with control subjects. Phys Ther.

1998;78(3):248–58.

26.

15. Boonstra MC, De Waal Malefijt MC, Verdonschot N. How to quantify knee function after total knee arthroplasty? Knee. 2008;15(5):390–5.

27.

16. Christiansen CL, Stevens-Lapsley JE. Weight-bearing asymmetry in relation to measures of impairment and functional mobility for people with knee osteoarthritis. Arch Phys Med Rehabil.

2010;91(10):1524–8.

28. Piva SR, Fitzgerald GK, Irrgang JJ, Bouzubar F, Starz TW. Get up and go test in patients with knee osteoarthritis. Arch Phys Med Rehabil.

2004;85(2):284–9.

29. Kennedy DM, Stratford PW, Wessel J, Gollish JD, Penney D. Assessing stability and change of four performance measures: a longitudinal study evaluating outcome following total hip and knee arthroplasty. BMC Musculoskel Dis. 2005;6:3.

30. Enright PL. The six-minute walk test. Resp Care.

2003;48(8):783–5.

31. Myers TA. Goodbye, Listwise Deletion: Presenting Hot Deck Imputation as an Easy and Effective Tool for Handling Missing Data. Commun Methods and Meas. 2011;5(4):297–310.

32. Cohen J. Applied Multiple Regression/correlation Analysis for the Behavioral Sciences. L. Erlbaum Associates; 1983:545.

17. Vahtrik D, Gapeyeva H, Ereline J, Pääsuke M. Relationship between leg extensor muscle strength and knee joint loading during gait before and after total knee arthroplasty. Knee. 2013.

18. Yoshida Y, Mizner RL, Snyder-Mackler L. Association between long-term quadriceps weakness and early walking muscle co-contraction after total knee arthroplasty. Knee. 2013;20(6):426–31.

19. Boonstra MC, Schwering PJA, Maarten C, Malefijt DW, Verdonschot N. Research Report Sit-to-Stand Movement as a Performance-Based Measure for.

Phys Ther. 2010;90(2):149–156.

20. Izquierdo M, Häkkinen K, Gonzalez-Badillo J, Ibáñez J, Gorostiaga E. Maximal strength and power characteristics in isometric and dynamic actions of the upper and lower extremities in middle-aged and older men. Acta Physiol Scand. 1999;167(1):57–68.

21. Sayers SP, Guralnik JM, Newman AB, Brach JS, Fielding RA. Concordance and discordance between two measurs of lower extremity functon 400m walk SPPB.pdf. Aging Clin Exp Res. 2006;18(2):100–106.

22. Bastiani D, Ritzel CH, Bortoluzzi SM, Vaz MA. Work and power of the knee flexor and extensor muscles in patients with osteoarthritis and after total knee arthroplasty. Rev Bras Reumatol. 2012;52(2):195–202.

23. Cuoco A, Callahan DM, Sayers S, Frontera WR, Bean J, Fielding R a. Impact of muscle power and force on

33. Preacher KJ. Calculation of the test of the difference between two independent correlation coefficients [Computer Software]. Available from http://www. quantpsy.org/corrtest/corrtest.htm,2002.

34. Lanza IR, Towse TF, Caldwell GE, Wigmore DM, Kent-Braun JA. Effects of age on human muscle torque, velocity, and power in two muscle groups.

J Appl Physiol. 2003;95(6):2361–9.

35. Farquhar SJ, Reisman DS. Research Report Persistence of Altered Movement Patterns During a Sit-to-Stand Task 1 Year Following Unilateral Total Knee Arthroplasty. Phys Ther. 2008;88(5):567–579.

36. Rowe PJ, Myles CM, Nutton R. The effect of total knee arthroplasty on joint movement during

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 177

functional activities and joint range of motion with particular regard to higher flexion users. J Orthop Surg (Hong Kong). 2005;13(2):131–8.

37. Aalund PK, Larsen K, Hansen TB, Bandholm T. Normalized knee-extension strength or leg-press power after fast-track total knee arthroplasty: which measure is most closely associated with performance-based and self-reported function? Arch Phys Med Rehabil. 2013;94(2):384–90.

38. Petterson SC, Mizner RL, Stevens JE, Raisis L, Bodenstab A, Newcomb W, Snyder-Mackler L. Improved function from progressive strengthening interventions after total knee arthroplasty: a randomized clinical trial with an imbedded

prospective cohort. Arthritis Rheum. 2009;61(2): 174–83.

39. Rossi MD, Brown LE, Whitehurst M. Knee extensor and flexor torque characteristics before and after unilateral total knee arthroplasty. Am J Phys Med Rehab. 2006;85(9):737–46.

40. Mizner RL, Petterson SC, Snyder-Mackler L. Quadriceps strength and the time course of functional recovery after total knee arthroplasty.

J Orthop Sports Phys Ther. 2005;35(7):424–36.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 178

IJSPT

ORIGINAL RESEARCH

A CRITERION BASED SLING WEANING PROGRESSION SWEAP AND OUTCOMES FOLLOWING SHOULDER ARTHROSCOPIC SURGERY IN AN ACTIVE DUTY MILITARY POPULATION Justin M. Hire, MD1 Joshua E. Pniewski, DPT2 Michelle L. Dickston, MPT2 Jeremy M. Jacobs, MD1 Terry L. Mueller, DO1 Brian E. Abell, DO1 John A. Bojescul, MD1

ABSTRACT Introduction: Little objective evidence is available to guide rehabilitation protocols in regard to the sling weaning process following arthroscopy surgery of the shoulder. The purpose of this study was to establish an objective, criterion based protocol for accelerated sling weaning following shoulder arthroscopy.

Methods: 82 active duty service members (ADSM) underwent elective shoulder arthroscopic surgery by three orthopaedic staff surgeons. One physical therapist progressed patients through the criterion based sling weaning progression (SWEAP) protocol for each surgery and documented pain levels, sleep habits, and decrease in sling use.

Preoperative and six month postoperative Quick Disability of the Arm, Shoulder, and Hand (qDASH) and Shoulder Pain and Disability Index (SPADI) scores were obtained. The ability to perform an Army Physical Fitness Test (APFT) was recorded at six months postoperative.

Results: Patients completed sling weaning at an overall mean of 16.6 ± 5.0 days with continued use in unprotected military settings only beyond this timeframe. As patients steadily progressed out of the sling for 1 hour, 2-3 hours, and half-day periods, average pain scores decreased during these time periods at 5.0±1.2, 3.7±1.2, and 2.1±1.3 (0-10 pain scale), respectively. Patients obtained 6-7 hours of sleep or normal sleep habits at an average of 10.9±4.4 days postoperative. Overall, preoperative qDASH and SPADI scores improved from 39.8±13.0 to 2.4±2.0 and 46.4±16.1 to 3.3±3.2, respectively, at 6 months follow up. All 82 patients were able to return to deployable status. 30 (36.6%) patients required formal restrictions for the push-up portion of the APFT at six months postoperative. 7 of these 30 patients required running restrictions.

Conclusions: Early improvement in quality of life indicators can be obtained in the initial postoperative period with a progressive, criterion based SWEAP protocol. Patients demonstrated favorable outcomes with return to occupational and physical fitness activities. This study will guide orthopedic surgeons and physical therapists to enhance the sling weaning process during rehabilitation protocols and improve preoperative counseling sessions for accurate postoperative expectations.

Study Design: Retrospective Case Series; Level of evidence 4.

Key Words: Shoulder arthroscopy, shoulder rehabilitation, sling weaning

1

Department of Orthopaedics, Dwight D. Eisenhower Army Medical Center, Fort Gordon, GA, USA 2 Department of Physical Therapy, Dwight D. Eisenhower Army Medical Center, Fort Gordon, GA, USA.

CORRESPONDING AUTHOR Justin M. Hire, MD Department of Orthopaedics Dwight D. Eisenhower Army Medical Center 300 Hospital Road, Orthopaedic Department Fort Gordon, GA, 30905 USA justin.m.hire.mil@mail.mil Office phone: 706-787-1859 Fax: 706-787-2901

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 179

INTRODUCTION The use of sling immobilization after arthroscopic shoulder surgery is well accepted to protect surgical repairs in the immediate postoperative period.

Postoperative stiffness is the most common complication ranging in incidence from 8.6-15% after these procedures and is often associated with prolonged immobilization.1-3 This can be true both for the duration of time immobilized in a sling, as well as the aggressiveness of the physical therapy protocol. Traditional protocols generally follow longer periods of time for sling use for all patients within a given protocol and do not individualize patient progression regarding sling use based upon objective criteria.1-5 Accelerated physical therapy protocols have been successful in decreasing pain scores and producing earlier functional activity and range of motion compared to conservative protocols.6 Little clinical evidence is available regarding objective criteria to successfully wean patients out of the sling, which is why consensus rehabilitation guidelines prevail in most physical therapy literature and medical center protocols.1,4 Given successful reports of accelerated rehabilitation protocols in shoulder arthroscopy and high patient satisfaction, the purpose of this study was to establish an objective, criterion based protocol for accelerated sling weaning following shoulder arthroscopy.6 The authors hypothesize that a criterion based early sling weaning protocol would yield improvements in quality of life with decreased pain and improved sleep habits with continued favorable outcomes at six month follow up.

MATERIALS AND METHODS All active duty service members (ADSM) undergoing shoulder arthroscopy and open pectoralis major repair as performed by three orthopaedic staff surgeons at a single institution from October 1, 2011 to October 31, 2012 were included in this retrospective review. Patients excluded from the study were retired soldiers, active duty patients who retired during follow up, soldiers in the Warrior Transition Battalion, soldiers undergoing the medical board process to exit military service, or soldiers with any concurrent neurologic or psychological diagnosis including, but not limited to traumatic brain injury. The local Institutional Review Board approved this study protocol.

One physical therapist followed these patients during their rehabilitation and documented pain levels, sleep habits, and decrease in sling use at all postoperative visits. The most restrictive SWEAP (longest duration of protocol) was utilized for patients undergoing multiple procedures. All SWEAP protocols are available in Table 1. In general, surgeries involving repairs had six weeks of sling weaning with earlier progression as allowed, based on criteria assessing compliance, pain, use of narcotics, passive range of motion, sleep habits, and ability to tolerate progression. This specific progression criterion outlined in Table 2 was reviewed at each visit and needed to be favorable in order to advance to the next phase of the protocol. After the sling could be discontinued per protocol, soldiers were still allowed to wear the sling in unprotected military settings. This is important for enlisted soldiers with less control over their surroundings as compared to commissioned officers.

All patients completed preoperative and six month postoperative Quick Disability of the Arm, Shoulder, and Hand (qDASH) and Shoulder Pain and Disability Index (SPADI) scores. These objective outcome scores are well validated in the literature.7-9 Active duty soldiers are required to take an Army Physical Fitness Test (APFT) twice a year which involves two minutes of pushups, two minutes of sit-ups, and a timed two mile run to gauge physical fitness. For medical reasons, soldiers can be granted formal restrictions or “profiles” by physicians on performing these activities. Soldiers’ profiles to be exempt from or be allowed to perform modified physical fitness activities for the APFT were reviewed at six months postoperative.

Statistical analysis was performed in SPSS version 19.

Descriptive data was generated for multiple variables including average time for sling use and pain. A series of independent t-tests were performed using age, gender, and profile status as the independent variables.

Data is reported as mean ± standard deviation. The null hypothesis for each test was rejected at p≤0.05.

RESULTS 82 ADSM including 73 males and 9 females with an average age of 34.2±8.7 years were included in the retrospective review. Individual procedures included 12 superior anterior to posterior labral (SLAP) repairs, 17 glenohumeral stabilization procedures

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 180

Table 1. Criterion Based Sling Weaning Progression (SWEAP) Protocols.

Table 2. Criterion Based Sling Weaning Progression (SWEAP) Protocol: Progression Criteria.

with 4 or less anchors involving ≤180˚ circumference, 5 glenohumeral stabilization procedures with 5 or more anchors involving >180˚ circumference, 10 rotator cuff repairs utilizing a single row technique with 1-2 anchors (all followed small-medium rotator cuff repair protocol), 33 open sub-pectoral biceps tenodeses, 2 biceps tenotomies, 13 distal clavicle resections, 10 coracoplasties, and 38 sub-acromial decompressions. Two pectoralis major repairs per-

formed in open fashion were included in the study due to requiring a sling during rehabilitation.

Data is summarized with a breakdown of individual protocols in Table 3. Patients were able to tolerate 1 hour without sling at average of 3.7±1.2 days postoperative, 2-3 hours without sling at 5.7±1.3 days postoperative, and half day at 8.1±2.0 days postoperative. 100% of patients completed sling weaning

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 181

Table 3. Summary of outcome data for all patients and individualized rehabilitation protocols.

All=All patients in subgroup, Permanent Profile= Patient required permanent profile at 6 months post-operative, No Permanent Profile= Patient did not require permanent profile at 6 months post-operative. *= Statistically significant after adjusting the p-value for multiple comparisons. p values provided are for comparison of soldiers with and without permanent profiles at 6 months post-operative.

before the individualized protocol goal at an overall average of 16.6±5.0 days postoperative (SLAP repairs 19.6±5.7, glenohumeral stabilization procedures with 4 or less anchors involving ≤180˚ circumference 16.1±4.1, glenohumeral stabilization procedures with 5 or more anchors involving >180˚ circumference 19.8±3.3, rotator cuff repair 23.1±4.5, biceps tenodesis/tenotomy procedures 13.5±2.3, pectoralis major repairs 20.0±1.4, and arthroscopy with no repairs performed 13.0±2.5).

Pain scores as measured on a 0-10 scale (0 for no pain, 10 for maximal pain) decreased from 5.0±1.2 when patients were trialing for 1 hour out of the sling, 3.7±1.2 when trailing for 2-3 hours out of the sling, and 2.1±1.3 when trailing for half day periods out of the sling. Those under age 35 reported significantly less pain after being out of a sling for half a day than those 35 years and older (1.71±1.3 vs 2.55±1.3, p=0.004). Patients obtained 6-7 hours or a normal night’s sleep at an average of 10.9±4.4 days postoperative. Females had a statistically significant more rapid return to normal sleep patterns

compared to males at 9.56±3.0 days postoperative compared to 11.04±4.6 days postoperative, respectively (p=0.04). Age and gender differences were not statistically significant for any other outcome parameter (p>0.05). No patient experienced clinical failure of any repair during the follow up period.

Overall, preoperative qDASH and SPADI scores improved from 39.8±13.0 to 2.4±2.0 and 46.4±16.1 to 3.3±3.2, respectively. All patients were deployable at six months postoperative. 30 (36.6%) patients required a profile for the push-up portion of the APFT at six months postoperatively. 7 of these 30 patients required running restrictions as well (1 for SLAP repair, 1 for glenohumeral stabilization procedure with 5 or more anchors involving >180˚ circumference, 2 for rotator cuff repair, 2 for isolated biceps tenodesis/tenotomy, and 1 for shoulder arthroscopy without repair).

Patients requiring a profile to be exempted for certain portions of the physical fitness test at six months postoperative were found to have a statistically significant increase in sling weaning time compared

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 182

Figure 1. Average decrease in sling use (days postoperative) throughout Criterion Based Sling Weaning Progression (SWEAP) as patient came out of sling for specified periods of time during protocol. Error bars reported as standard error of the mean. *Solid line=All Patients, Dotted Line= Patients with Profile, Dashed Line= Patients without Profile.

to soldiers not requiring profiles (18.6±6.0 days vs 15.4±4.0 days, p=0.014*) (Figure 1), increased time to obtain normal sleep habits (13.3±4.8 days vs 9.5±3.6 days, p=<0.001*), and increased pain scores at the later portion of sling weaning (4.3±1.2 vs 3.3±1.1, P=0.001 at 2-3 hours without sling, 2.6±1.3 vs 1.8±1.2, p=0.008 at half day without sling) (Figure 2).

copy including accelerated rehabilitation protocols, customized physical therapy programs, and early use of passive motion.6,10-12 Improvements in surgical repairs have enabled surgeons and physical therapists to explore these options with less fear of hardware or soft tissue repair failures.

DISCUSSION Many studies have evaluated rehabilitation methods in order to improve outcomes after shoulder arthros-

Penna et al performed a cadaveric study to test the strength of transglenoid sutures for labral and capsular shift repair techniques.13 The greatest stress was found in the abducted and externally rotated position at a mean force of 17.7N in the capsular shift with labral repair group. The maximum chondrolabral junction force in any trial was 26.1N which is still significantly below the biomechanical pullout strength of a knotless anchor at 650N as documented by Leedle and Miller.14 An update on pullout strengths and modes of failure utilizing a biomechanical analysis found most current anchors fail by eyelet failure followed by suture breakage.15 Pullout was not the predominant mode of failure for any anchor tested. Mean force for load to failure in cortical bone ranged from mean force of 161.1-521.6N and 116.8-611.8N for cancellous bone.

*Represents statistically significant differences between groups after accounting for unequal variances.

For rotator cuff repairs, cadaveric and animal models have demonstrated that the mode of failure has been

Preoperative qDASH and SPADI were significantly worse for patients with profiles at 47.1±13.5 and 55.7±13.3 compared to patients without profiles at 35.6±10.9 and 41.1±15.2, respectively (p=<0.001, p=<0.001*). Patients with profiles experienced a more significant quantitative change in outcome scores postoperative, but were still significantly worse than patients without profiles (postoperative qDASH 3.7±1.9 vs 1.7±1.8 p=<0.001, postoperative SPADI 4.7±3.8 vs 2.4±2.5 p=0.002).

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 183

Figure 2. Average pain level decreases throughout Criterion Based Sling Weaning Progression (SWEAP) as patient came out of sling for specified amounts of time during protocol. Error bars reported as standard error of the mean. *Solid line=All Patients, Dotted Line= Patients with Profile, Dashed Line= Patients without Profile.

effectively transferred to the soft tissue instead of bone tunnel fracture or suture breakage with modern anchor fixation over bony tunnels.16,17 These tests demonstrate improvement over historical repair methods and have allowed for further enhancement of rehabilitation protocols with biology now becoming the limiting factor in most cases.18 Consensus rehabilitation guidelines currently offer poor objective criteria for sling weaning. The American Society of Shoulder and Elbow Therapists provided the first multidisciplinary guideline in 2010 for therapy following arthroscopic anterior stabilization with or without Bankart repair which states a range of 0-4 weeks immobilization “dependent on patient’s specific injury/pathology, co-morbidities, amount of natural laxity, past surgical history, specific surgical technique (including type of fixation and arm position at time of capsular plication), and physician philosophy”.1,4 This criterion gives a wide range of interpretation and offers little direct evidence for rehabilitation. These guidelines are similar to most large rehabilitation center protocols being formed mostly by expert opinion in Gestalt methodology.

After reviewing all available literature, the AAOS

Clinical Practice Guideline Summary for Optimizing the Management of Rotator Cuff Problems offers inconclusive recommendations for any purpose concerning immobilization duration or position.19 Stiffness continues to be a persistent postoperative complication following surgery on the glenohumeral joint which occasionally requires further operative intervention. Tokish et al prospectively followed 41 patients undergoing circumferential labral repairs and kept all patients in an abduction sling for six weeks except for bathing and range of motion of the elbow, wrist, and hand.5 Pendulum exercises began at two weeks postoperative with a supervised physical therapy program not starting until six weeks postoperative. Two of 39 patients available at 31.8 month follow up developed postoperative stiffness and tightness requiring further arthroscopic release.

Those authors concluded that a less aggressive rehabilitation protocol could have contributed to stiffness in these patients.

Patient dissatisfaction from prolonged immobilization may be considered a complication affecting the patient’s perceived results of shoulder arthroscopy.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 184

Kim et al performed a prospective randomized clinical study of an accelerated rehabilitation protocol following arthroscopic Bankart repair.6 The control group remained immobilized for three weeks, but was allowed to wash the axilla daily and able to flex their wrist and elbow during this time. The accelerated group began gradual exercise on postoperative day one and wore the sling during sleep for two weeks. Minimal documentation was provided for directing sling use by the authors of this article.

However, the authors found statistically significant favorable results in reducing pain at six weeks postoperative, improving patient satisfaction, earlier return of range of motion, and earlier return of functional activity level with the accelerated protocol (p<0.05). Final follow up demonstrated no difference in recurrence of instability, objective outcome scores, pain, or return to prior activity. Satisfaction was measured one year postoperatively with 64% of patients in the control protocol recalling an “unsatisfactory” rehabilitation protocol compared with only 9% in the accelerated protocol.

Utilizing the criterion based sling weaning progression (SWEAP) protocol described in the current study, patients reported decreasing pain scores that progressively improved as less time was spent immobilized in the sling. Normal sleep patterns were obtained before the standard two week follow up appointment for most patients. The SWEAP protocol utilized in this study can supplement the current rehabilitation therapies at most major medical centers and rehabilitation facilities.

Soldiers who ultimately required formal physical activity restrictions or “profiles” had increased time for sling weaning, increased postoperative days to obtain normal sleep habits, and increased pain scores during the sling weaning timeframe. Increased disability on preoperative and postoperative qDASH and SPADI scores was found for patients who required these formal restrictions compared to patients who did not require a profile at six months follow up. The postoperative difference in qDASH and SPADI scores, although statistically significant after controlling for multiple comparisons, had an absolute value difference of only two points. This minimal difference would not be expected to correlate with a significant increase of functional disability requiring a profile for

the APFT. The increased qDASH and SPADI scores in this group could potentially be attributed to differences in pain tolerance or willingness to report pain.

Another explanation is the potential for secondary gain for some soldiers to attempt to decrease their physical fitness requirements even though they may have similar qDASH and SPADI scores compared to a more motivated soldier. This study gives general statistics that about one-third of soldiers undergoing shoulder arthroscopy will require a profile which will aid preoperative counseling, but this finding needs to be studied more in future research, and discussion needs to be individualized for every soldier’s diagnosis and planned surgery as demonstrated in Table 3.

LIMITATIONS Limitations of this study include its retrospective nature and relatively small sample size for each individual type of surgery. No control group was available at the authors’ institution and no representative standard was found in literature to compare our results. All data collection was obtained by one physical therapist which could introduce an element of bias. Patients were allowed to continue to wear the sling in unprotected military settings which was unable to be quantitatively documented. The vast majority of patients were male which reflects the military patient population. Increasing the number of patients including an equal balance of males and females, comparing results to a control group, and increasing the duration of follow up would strengthen the findings. Musculoskeletal ultrasound would also be a useful adjunct to evaluate the integrity of the repair for patients undergoing rotator cuff repair in addition to their clinical outcome.20,21 CONCLUSION This study documents the initial favorable quality of life outcomes in the first six postoperative weeks and positive objective outcomes at six months postoperative following an accelerated SWEAP protocol after shoulder arthroscopy for a wide variation of surgical procedures in a military population. The majority of patients (63.4%) were able to pass an unrestricted Army Physical Fitness Test (APFT) at six months postoperative. At this timeframe, excellent return to occupational activities was demonstrated with all patients being deployment-eligible and being able to

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 185

return to their prior military specialty. This data will improve preoperative counseling for patient expectations and provide physical therapists with objective criteria for sling weaning during the rehabilitation process.

11.

REFERENCES 1. Gaunt BW, Shaffer MA, Sauers EL, Michener LA, McCluskey GM, Thigpen C. The American Society of Shoulder and Elbow Therapists’ consensus rehabilitation guideline for arthroscopic anterior capsulolabral repair of the shoulder. J Orthop Sports Phys Ther. Mar 2010;40(3):155-168.

2. Parsons BO, Gruson KI, Chen DD, Harrison AK, Gladstone J, Flatow EL. Does slower rehabilitation after arthroscopic rotator cuff repair lead to longterm stiffness? J Shoulder Elbow Surg. Oct 2010;19(7):1034-1039.

3. van der Meijden OA, Westgard P, Chandler Z, Gaskill TR, Kokmeyer D, Millett PJ. Rehabilitation after arthroscopic rotator cuff repair: current concepts review and evidence-based guidelines. Int J Sports Phys Ther. Apr 2012;7(2):197-218.

4. Consensus Rehabilitation Guidelines: Arthroscopic Anterior Stabilization with or without Bankart Repair. Revised 2007; www.asset-usa.org/Guidelines/ Arthroscopic_Anterior_Stabilization.pdf. Accessed August 6, 2013.

5. Tokish JM, McBratney CM, Solomon DJ, Leclere L, Dewing CB, Provencher MT. Arthroscopic repair of circumferential lesions of the glenoid labrum. J Bone Joint Surg Am. Dec 2009;91(12):2795-2802.

6. Kim SH, Ha KI, Jung MW, Lim MS, Kim YM, Park JH. Accelerated rehabilitation after arthroscopic Bankart repair for selected cases: a prospective randomized clinical study. Arthroscopy. Sep 2003;19(7):722-731.

7. Beaton DE, Richards RR. Measuring function of the shoulder. A cross-sectional comparison of five questionnaires. J Bone Joint Surg Am. Jun 1996;78(6):882-890.

8. Hill CL, Lester S, Taylor AW, Shanahan ME, Gill TK. Factor structure and validity of the shoulder pain and disability index in a population-based study of people with shoulder symptoms. BMC Musculoskelet Disord. 2011;12:8.

9. Matheson LN, Melhorn JM, Mayer TG, Theodore BR, Gatchel RJ. Reliability of a visual analog version of the QuickDASH. J Bone Joint Surg Am. Aug 2006;88(8):1782-1787.

10. Koo SS, Parsley BK, Burkhart SS, Schoolfield JD. Reduction of postoperative stiffness after

12.

13.

14.

15.

16.

17.

18.

19.

20.

arthroscopic rotator cuff repair: results of a customized physical therapy regimen based on risk factors for stiffness. Arthroscopy. Feb 2011;27(2):155160.

Lee BG, Cho NS, Rhee YG. Effect of two rehabilitation protocols on range of motion and healing rates after arthroscopic rotator cuff repair: aggressive versus limited early passive exercises.

Arthroscopy. Jan 2012;28(1):34-42.

Peltz CD, Dourte LM, Kuntz AF, et al. The effect of postoperative passive motion on rotator cuff healing in a rat model. J Bone Joint Surg Am. Oct 2009;91(10):2421-2429.

Penna J, Deramo D, Nelson CO, et al. Determination of anterior labral repair stress during passive arm motion in a cadaveric model. Arthroscopy. Aug 2008;24(8):930-935.

Leedle BP, Miller MD. Pullout strength of knotless suture anchors. Arthroscopy. Jan 2005;21(1):81-85.

Barber FA, Herbert MA, Hapa O, et al.

Biomechanical analysis of pullout strengths of rotator cuff and glenoid anchors: 2011 update.

Arthroscopy. Jul 2011;27(7):895-905.

Burkhart SS, Diaz Pagan JL, Wirth MA, Athanasiou KA. Cyclic loading of anchor-based rotator cuff repairs: confirmation of the tension overload phenomenon and comparison of suture anchor fixation with transosseous fixation. Arthroscopy. Dec 1997;13(6):720-724.

Demirhan M, Atalar AC, Kilicoglu O. Primary fixation strength of rotator cuff repair techniques: a comparative study. Arthroscopy. Jul-Aug 2003;19(6):572-576.

Gerber C, Schneeberger AG, Beck M, Schlegel U. Mechanical strength of repairs of the rotator cuff.

J Bone Joint Surg Br. May 1994;76(3):371-380.

Pedowitz RA, Yamaguchi K, Ahmad CS, et al.

American Academy of Orthopaedic Surgeons Clinical Practice Guideline on: optimizing the management of rotator cuff problems. J Bone Joint Surg Am. Jan 18 2012;94(2):163-167.

Paxton ES, Teefey SA, Dahiya N, Keener JD, Yamaguchi K, Galatz LM. Clinical and radiographic outcomes of failed repairs of large or massive rotator cuff tears: minimum ten-year follow-up. J Bone Joint Surg Am. Apr 3 2013;95(7):627-632.

21. Prickett WD, Teefey SA, Galatz LM, Calfee RP, Middleton WD, Yamaguchi K. Accuracy of ultrasound imaging of the rotator cuff in shoulders that are painful postoperatively. J Bone Joint Surg Am. Jun 2003;85-A(6):1084-1089.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 186

IJSPT

ORIGINAL RESEARCH

INTRARATER AND INTERRATER RELIABILITY OF THE FIVE IMAGEBASED CRITERIA OF THE FOOT POSTURE INDEX6 Masafumi Terada, MS, ATC1 Ara M. Wittwer, MS, ATC1 Phillip A. Gribble, PhD, ATC1

ABSTRACT Purpose/Background: The Foot Posture Index-6 (FPI-6) is considered a simple quantification tool to assess static foot alignment. Palpation of the foot is required for assessment of one of the six criteria that comprise the FPI-6; the remaining five criteria may be evaluated using still-frame photographs. Using only the image-based criteria may allow multiple clinicians to evaluate large groups of patients quickly. Reliability using only these five image-based criteria has not been established. The purposes of the current study were to establish the inter- and intra-rater reliability using five image-based criteria from the Foot Posture Index-6 (FPI-6) as well as to examine the agreement between the raters in identifying foot type using the composite five FPI scores.

Methods: Forty participants (23 females, 17 males; 23.67 ± 8.49 years; 64.59 ± 14.43 kg; 166.07 ± 11.79 cm) volunteered for this study. An investigator took three photos with a digital camera of the medial longitudinal arch, posterior ankle, and of the talonavicular joint approximately 45⬚ from the posterior calcaneus for both right and left feet. Two investigators assessed the five image-based criteria of the FPI-6 for both feet of 40 participants on three occasions separated by a day. Inter-and intra-rater reliability were assessed with Intraclass Correlation Coefficients (ICC3,2). The amount of agreement for classification of foot posture type between the two raters was assessed with Cohen’s kappa coefficient. Significance was set a priori at P < 0.05.

Results: The inter-rater reliability was poor to moderate for all three sessions (ICC3,2 = 0.334-0.634). For the foot posture classification, the amount of agreement between two raters was poor for left (κ= 0.12) and right (κ= 0.19) feet.

The intra-rater reliability was excellent for left (ICC3,2=0.956) and right feet (ICC3,2=0.959).

Conclusions: Excellent intra-rater and poor to moderate inter-rater reliability was found using only the five imagebased criteria of the FPI-6. However, the classification of foot posture did not improve the amount of agreement between raters. Therefore, caution is needed when interpreting FPI scores from five image-based criteria.

Levels of Evidence: 3b Keywords: Foot posture, reliability, static postural assessment

1

University of Toledo, Toledo, OH, USA

Conflict of Interests We certify that no party having a direct interest in the results of the research supporting this article has or will confer a benefit on us or on any organization with which we are associated. No conflicts of interest are directly relevant to the content of this study.

Ethical approval The methods used in this study have been approved by the internal review board at the University of Toledo.

CORRESPONDING AUTHOR Masafumi Terada, MS, ATC 2801 W Bancroft Street, Mailstop#119 University of Toledo Toledo OH 43606 Tel: 419-530-2691 Fax: 419-530-2477 E-mail: mterada@rockets.utoledo.edu

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 187

INTRODUCTION It is important for sports-related injury prevention to identify potential risk factors. Foot posture is one factor considered when examining risk of sportsrelated injury.1-3 Static foot alignment is frequently assessed to identify foot posture in clinical practice for evaluating injury risk and determining a course of therapeutic intervention to decrease the risk.

The Foot Posture Index-6 (FPI-6) is considered a fast, simple, inexpensive, and multisegmental clinical quantification tool to assess static foot alignment in all three planes and to classify foot posture types.4 The FPI-6 consists of six individual criteria (Table 1), each having a 5-point scale that ranges from –2 to +2, with negative numbers indicating a more supinated foot posture and positive numbers indicating a more pronated foot posture.5 A composite FPI-6 score ranges from –12 to +12, and a foot type is classified as a highly pronated posture with a score of 10 or greater, a pronated posture with scores of +6 to +9, normal posture with scores of 0 to +5, a supinated posture with scores of –4 to –1, or a highly supinated posture with ≤–5.4,6,7 The FPI-6 has demonstrated good construct validity as a clinical instrument,6 and has been used in clinical and research settings to identify risk factors for sports-related injuries.1,8,9

Direct patient contact is required for assessment of one of the six criteria that comprise the FPI-6, specifically palpation of the head of the talus to assess rearfoot alignment. The remaining five criteria of the FPI-6 are evaluated based on visual observations of the rearfoot, midfoot, and forefoot of a patient. When evaluating an individual patient in a clinical setting, the time needed to complete the direct visual observation criteria is typically available to the patient and clinician. However, when screening large groups of physically active individuals to identify injury risk, it is critical for selected screening measures to be much more time efficient. While direct visual observation has typically been performed for the FPI-6 assessment, if the five image-based criteria could be evaluated effectively with a digital image after the physical screening is complete, it would allow multiple clinicians to evaluate large groups of individuals more efficiently, as well as patients not to be present excessive time during the assessment.

The reliability of clinicians’ ratings of postural evaluation is crucial for assessment and the interpretation of examination findings in clinical practice and research.10 If using only the five-imaged criteria of the FPI-6 is reliable, this could introduce a foot posture assessment into a pre-participation examination for injury prediction

Table 1. The five image-based criteria of the Foot Posture Index (FPI-6) Criteria4,5

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 188

Figure 1. Three photos of the medial longitudinal arch (A), posterior ankle (B), and talonavicular joint (C).

and determination of appropriate intervention, without introducing excessive time demands on the patient, clinician, or researcher during the assessment. Although previous authors8,11-14 have reported that the FPI-6 has a moderate to excellent inter-and intra-rater reliability, reliability using only these five image-based criteria has not been established. Therefore, the purposes of the current study were to establish the inter- and intrarater reliability using the five image-based criteria from the FPI-6 as well as examine the agreement between the raters in identifying foot type using the composite five FPI scores.

METHODS Design Using a descriptive laboratory study design, the main outcome variables of the total score using the five imaged-based criteria of the FPI-6 and a foot posture type classified based on the composite scores were assessed across sessions (day 1, day 3, day 5) and raters (rater 1, rater 2).

Participants Forty volunteers (23 females, 17 males, age = 23.67 ± 8.49 years, body mass = 64.59 ± 14.43 kg, height = 166.07 ± 11.79 cm) participated in this study. Participants signed an informed consent form approved by the University of Toledo Institutional Review Board.

Procedures Two investigators served as raters of the five imagebased criteria of the FPI-6 for both feet of 40 participants on three occasions each separated by a day.

Rater 1 and 2 were certified athletic trainers with

postgraduate clinical experiences. Neither rater had previous experience using the FPI-6 in their clinical practice. The raters were exposed to the use of the FPI-6 during pilot work on 15 participants that were not included in this study’s sample. During the pilot work, the raters performed the FPI-6 assessment using the original protocol4 and were allowed to have open discussion about the index criteria.

Participants were asked to take several steps in place and stand in a relaxed stance with double-limb support, arms by the side, and looking straight ahead.

Participants maintained this comfortable stance position while an investigator took three photos of the medial longitudinal arch (Figure 1-A), posterior ankle (Figure 1-B), and talonavicular joint (Figure 1C) for both right and left feet with a digital camera (Kodak EasyShare M853; Rochester, New York). The camera was positioned approximately 30cm from the medial side of the foot for the medial longitudinal arch, approximately 25 cm from the posterior aspect of the calcaneus for the posterior ankle view, as well as 25 cm from the talonavicular joint and approximately 45⬚ from the posterior calcaneus for the talnavicular joint view. Using the photographs, the two raters independently scored both feet of each of the 40 participants based on the five imagebased criteria of the FPI-6 on the same day that the photographs were taken. Two and four days later, the raters assessed the same photographs again in a random order and scored static foot alignment on each photo with the five image-based criteria of the FPI-6 again (Table 1). Each criterion was scored on a scale of –2 to +2, with a total FPI score ranging from –10

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 189

to +10. Each participant’s foot was classified based on an established version (6 criteria) of the composite FPI score as “highly pronated” with a score of ≥10, “pronated” with scores of 6 to 9, “normal” with scores of 0 to 5, “supinated” with scores of –1 to –4, or “highly supinated” with scores of ≤–5.4,6 Statistical Analyses To assess inter-rater reliability, Intraclass Correlation Coefficients (ICC3,2) with 95% confidence intervals (CI) were calculated for the total FPI scores for two raters for each individual assessment session.

The intra-rater reliability (ICC3,3) of the average FPI scores of two raters [(Rater 1 score + Rater 2 score)/2] for each posture assessment session was determined. The intra-rater reliability of the composite score of five image-based criteria of FPI-6 was also assessed for each rater. Intraclass Correlation Coefficients were interpreted as poor (0.0-0.50), moderate (0.51-0.75), good (0.76-0.90), or excellent (0.91–1.00).15 Cohen’s kappa coefficient (κ) was used to examine the amount of agreement for classification of foot posture type between the two raters.16 The degree of agreement for classification was inter-

preted as poor (κ ≤ 0), slight (0.01 ≤ κ ≤ 0.20), fair (0.21 ≤ κ ≤ 0.40), moderate (0.41 ≤ κ ≤ 0.60), substantial (0.61 ≤ κ ≤ 0.80), almost perfect (0.11 ≤ κ ≤ 1.00).17-20 All analyses were completed for the left and right feet of the models, but no side-to-side comparisons were performed. Significance was set a priori at P < 0.05. All statistical tests were performed using SPSS 17.0 (SPSS, Inc, Chicago, IL).

RESULTS The means of the total of all FPI scores using fiveimaged criteria across three assessments and two raters were 2.84 ± 2.06 for left and 1.47 ± 2.26 for right feet. The means of the total of all FPI scores using five-imaged criteria for two raters for each assessment session are provided in Table 2. The inter-rater reliability for each session was poor to moderate with large 95% CIs (Table 3). For the classification of foot posture based on raw scores, as well as the amount of agreement between two raters was poor for both left (κ = 0.12) and right (κ = 0.19) feet.

The number of foot posture types classified by two raters based on the raw Foot Posture Index scores is provided in Table 4.

Table 2. The Average Total Scores (Mean ± SD) from Five Imaged-based Criteria of Foot Posture Index-6

Table 3. Inter-Rater Reliability Data.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 190

Table 4. The number of foot posture types classified by two raters based on the raw Foot Posture Index scores (80 feet)

The intra-rater reliability was excellent for both left (ICC3,3 = 0.956, 95% CI; 0.925, 0.975, standard error of measurement [SEM] = 1.25) and right feet (ICC3,3 = 0.959, 95% CI; 0.931, 0.977, SEM =1.33) when the average of the total FPI scores for two raters for each posture assessment session was analyzed between the sessions. Rater 1 had excellent reliability for left (ICC3,3 = 0.900, 95% CI; 0.832, 0.944, SEM =1.85) and good for right (ICC3,3 = 0.895, 95% CI; 0.822, 0.941, SEM =1.77) between the sessions. Rater 2 demonstrated excellent reliability for both left (ICC3,3 = 0.952, 95% CI; 0.819, 0.973, SEM = 1.69) and right (ICC3,3 = 0.950, 95% CI; 0.915, 0.972, SEM = 2.02) between the sessions.

DISCUSSION Focusing on the image-based visual observation may allow clinicians to save assessment time, and multiple clinicians to evaluate large groups of patients quickly. Establishing the reliability of clinicians’ rating digital, rather than live, observations from this assessment tool may be important for foot posture assessments and the interpretation of the findings in clinical and research settings. This study showed poor to moderate inter-rater reliability and excellent intra-rater reliability when using only the five image-based criteria of the FPI-6. The measurements of reliability for the five image-based criteria of the FPI-6 are similar to previously published reli-

ability of the measurements using all criteria of the FPI-6.8,11 However, the classification of foot posture did not improve the amount of agreement between raters. This finding of the categorization based on the raw FPI score using Kappa coefficient analysis contradicted the results of Morrison and Ferrari.13 While reliability of the FPI-6 has been reported previously, to the authors’ knowledge, this is the first study to establish reliability only of the five observation-based criteria of the FPI-6. Cornwall et al11 reported excellent intra-rater reliability of the FPI-6 among three clinicians who had different levels of clinical experience. Cain et al8 and Evans et al14 also demonstrated excellent intra-rater reliability of the FPI-6 in pediatric population among clinicians with various levels of clinical experiences. In our study, both raters had similar experience with the FPI-6 and demonstrated excellent intra-rater reliability when using only the five-image-based criteria of the FPI6. The current results, coupled with these previous reports, seem to support the FPI as a reliable clinical tool for assessing static foot alignment, regardless of clinical experience with the tool.

However, caution is needed when interpreting FPI scores from five image-based criteria. The authors of the current study found poor to moderate interrater reliability for raw FPI scores with large 95% CIs and poor agreement between raters when the

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 191

average FPI scores for each rater for each assessment were used to classify each foot using the scales presented by Redmond et al4 Cornwall et al11 also reported moderate agreement among clinicians for both the FPI-6 raw scores and classification of foot posture based on the raw scores. In contrast, using the FPI-6 in pediatric population, Morrison and Ferrari13 reported almost perfect agreement between two observers who were considered to have similar experience with using the FPI-6 when the FPI-6 scores were categorized. Barton et al21 demonstrated good inter-rater reliability among three raters in individuals with knee pain. The wide variety of results may be attributable to differences in the populations studied across these studies, as well as observing and rating static foot alignment with individual criteria of the FPI-6. Because several age-related changes in function influences foot posture and structure,22 the current results obtained from a young adult population cannot be assumed to be equally reliable when the FPI is applied to other populations. While direct visual observations of each participant’s foot were performed for this assessment in the study of Morrison and Ferrari,13 the raters in the current study observed static foot alignment using photographs of the ankle and foot in order to score on the FPI. Additionally, the two raters in our current study had no experience with the index criteria. While the raters were exposed to the use of the FPI-6 and the rating scale for each of the criteria during pilot work with open discussion about the index criteria, the two raters did not receive standardized training from a clinician who has previous experiences with the FPI-6.

Therefore, the lower inter-rater reliability may be associated with the level of two raters’ experiences with FPI assessment.

LIMITATIONS The primary limitation of this study is that the authors’ used the categories of foot posture that were proposed for the actual FPI-6 by Redmond et al.4 The actual FPI-6 has six individual criteria which are summated to yield a composite score (–12 to +12) that is then used to classify foot posture based upon cutoff scores established by a previous study.4 However, the raters observed and rated static foot posture with incorporation using only the five image-based criteria of the FPI-6. This current study used an

established composite score ranging from –12 to +12 and the cutoff scores previously established for the actual FPI-6 to classify each participant’s foot. The established composite FPI-6 score from –12 to –5 was classified as highly supinated, –1 to –4 as supinated, 0 to +5 as neutral, +6 to +9 as pronated, and +10 to +12 as highly pronated.4,6 However, we used only the five imaged-based criteria of the FPI-6 and the actual composite scores could only range from –10 to +10.

It is possible that the use of the FPI composite score as the reference cutoff score negatively influenced the classification of foot posture in this study. Therefore, different cut-off values for foot posture classification may be required when using only the five imaged based criteria of the FPI-6 to screen foot posture types. Future research should investigate what cut-off score is best for using only the five imagebased criteria of FPI-6. Furthermore, the palpation measure provides information regarding the orientation of the head of the talus. It is unknown how taking out the talar head palpation criterion from the original FPI-6 influences validity of static foot posture assessment. Further investigation is necessary to determine validity of the five image-based criteria of the FPI-6 and the correlation between the palpation and observation criteria of the FPI-6.

While previous studies demonstrated good internal construct validity of the actual FPI-6,5,6,23 the validity of the FPI incorporating only the five observation-based criteria remains unknown, resulting in agreement between raters that was perhaps underestimated and not generalizable.20 Establishing validity of this assessment may be necessary in order to provide accurate evaluation of the foot posture. Furthermore, the sample size used in this study may lead to underestimation of Cohen’s Kappa analysis.20 Although thirty cases with two raters was deemed appropriate for this study, larger sample sizes are mathematically more likely to produced very small confidence intervals, which may lead to more precise estimates of agreement. Further investigation with a larger sample size may be necessary to establish normative values for the FPI composite score based upon only the five image-based criteria.

This image-based visual observation is important and useful to clinicians because this may allow them to save assessment time, and multiple clinicians to

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 192

evaluate large groups of patients quickly. However, scoring of the FPI appears to be influenced by soft tissue morphology,23 and slight changes in angle for observation may lead to inconsistent observations of static foot posture between clinicians. While the investigators in this current study made efforts to take the photographs as consistently as possible, it is possible that minor inconsistencies in the photographs of each participant could have negatively influenced the quality of the assessment of each image-based criterion. However, the current results still demonstrated moderate to excellent associated reliability.

Finally, the participants were from a sample of convenience; therefore, there was no control for the distribution of foot types among participants. It will be important in the future investigations to consider recruiting equal distributions of foot type among the participants enrolled.

CONCLUSION The FPI-6 is a clinical evaluation tool used to assess static foot posture in all three planes, which includes five multisegmental visually observable criteria and an additional criterion of talar head palpation. Using only the five image-based criteria of the FPI-6 may be beneficial for clinicians to save assessment time and evaluate large groups of patients quickly. The results of the current study indicate that the use of only the five image-based criteria of the FPI-6 demonstrates strong intra-rater but poor to moderate inter-rater reliability. Additionally, the visual attempt at classification of foot posture demonstrated poor agreement between raters. Therefore, caution is needed when interpreting FPI scores from the five imagebased criteria. It is important for future investigations to establish appropriate cutoff values for the foot posture classification system using only the five image-based criteria, as well as normative values for the FPI composite scores, with larger sample sizes, in order to effectively assess static foot posture.

REFERENCES 1. Burns J, Keenan AM, Redmond A. Foot type and overuse injury in triathletes. J Am Podiatr Med Assoc.

2005;95(3):235-241.

2. Cowan DN, Jones BH, Robinson JR. Foot morphologic characteristics and risk of exerciserelated injury. Arch Fam Med. 1993;2(7):773-777.

3. Sommer HM, Vallentyne SW. Effect of foot posture on the incidence of medial tibial stress syndrome.

Med Sci Sports Exerc. 1995;27(6):800-804.

4. Redmond AC, Crosbie J, Ouvrier RA. Development and validation of a novel rating system for scoring standing foot posture: The foot posture index. Clin Biomech (Bristol, Avon). 2006;21(1):89-98.

5. Teyhen DS, Stoltenberg BE, Eckard TG, et al. Static foot posture associated with dynamic plantar pressure parameters. J Orthop Sports Phys Ther.

2011;41(2):100-107.

6. Keenan AM, Redmond AC, Horton M, Conaghan PG, Tennant A. The foot posture index: Rasch analysis of a novel, foot-specific outcome measure. Arch Phys Med Rehabil. 2007;88(1):88-93.

7. Redmond AC, Crane YZ, Menz HB. Normative values for the foot posture index. J Foot Ankle Res. 2008;1(1):6.

8. Cain LE, Nicholson LL, Adams RD, Burns J. Foot morphology and foot/ankle injury in indoor football.

J Sci Med Sport. 2007;10(5):311-319.

9. Hreljac A, Marshall RN, Hume PA. Evaluation of lower extremity overuse injury potential in runners.

Med Sci Sports Exerc. 2000;32(9):1635-1641.

10. Sim J, Wright CC. The kappa statistic in reliability studies: Use, interpretation, and sample size requirements. Phys Ther. 2005;85(3):257-268.

11. Cornwall MW, McPoil TG, Lebec M, Vicenzino B, Wilson J. Reliability of the modified foot posture index. J Am Podiatr Med Assoc. 2008;98(1):7-13.

12. Barton CJ, Levinger P, Crossley KM, Webster KE, Menz HB. Relationships between the foot posture index and foot kinematics during gait in individuals with and without patellofemoral pain syndrome.

J Foot Ankle Res. 2011;4:10.

13. Morrison SC, Ferrari J. Inter-rater reliability of the foot posture index (fpi-6) in the assessment of the paediatric foot. J Foot Ankle Res. 2009;2:26.

14. Evans AM, Rome K, Peet L. The foot posture index, ankle lunge test, beighton scale and the lower limb assessment score in healthy children: A reliability study. J Foot Ankle Res. 2012;5(1):1.

15. Portney LG, Watkins MP. Foundations of clinical research : Applications to practice. 3rd ed. Upper Saddle River, N.J.: Pearson/Prentice Hall; 2009.

16. Cohen J. Citation-classic - a coefficient of agreement for nominal scales. Cc/Soc Behav Sci. 1986(3):18-18.

17. Fleiss JL. Measuring nominal scale agreement among many raters. Psychological Bulletin.

1971;76(5):378-382.

18. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics.

1977;33(1):159-174.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 193

19. Kundel HL, Polansky M. Measurement of observer agreement. Radiology. 2003;228(2):303-308.

20. Crewson PE. Fundamentals of clinical research for radiologists - reader agreement studies. Am J Roentgenol. 2005;184(5):1391-1397.

21. Barton CJ, Bonanno D, Levinger P, Menz HB. Foot and ankle characteristics in patellofemoral pain syndrome: A case control and reliability study.

J Orthop Sports Phys Ther. 2010;40(5):286-296.

22. Endo M, Ashton-Miller JA, Alexander NB. Effects of age and gender on toe ďŹ&#x201A;exor muscle strength.

J Gerontol A Biol Sci Med Sci. 2002;57(6):M392-397.

23. Menz HB, Munteanu SE. Validity of 3 clinical techniques for the measurement of static foot posture in older people. J Orthop Sports Phys Ther.

2005;35(8):479-486.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 194

IJSPT

ORIGINAL RESEARCH

INTRA AND INTERRATER RELIABILITY OF THE SELECTIVE FUNCTIONAL MOVEMENT ASSESSMENT SFMA Kathryn R. Glaws, PT, DPT, CSCS1,2 Christopher M. Juneau, PT, DPT, CSCS1,2 Lindsay C. Becker, PT, DPT, SCS, CSCS1,2 Stephanie L. Di Stasi, PT, PhD, OCS1,2,3,4,6 Timothy E. Hewett, PhD1,2,3,4,5

ABSTRACT Purpose/Background: The Selective Functional Movement Assessment (SFMA) is a clinical assessment system designed to identify musculoskeletal dysfunction by evaluation of fundamental movements for limitations or symptom provocation. The purpose of this study was to determine the intra- and inter-rater reliability of the ten fundamental movement patterns of the SFMA in a healthy population using the SFMA categorical and criterion checklist scoring tools.

Methods: 35 healthy subjects (22.9 years +/- 1.9) were recorded with two digital video cameras (1-frontal view/1sagittal view) while they performed the ten fundamental movements patterns that comprise the SFMA. Evaluators with varying experience with the SFMA (rater A, > 100 hours; rater B, 25 hours; and rater C, 16 hours) and not present at the initial data collection evaluated each video using categorical and criterion checklist scoring tools. Evaluators repeated this process at least one week later. The evaluators’ composite results were compared between and within raters using the kappa coefficient and ICC’s for categorical scoring and criterion checklist scoring, respectively.

Results: Substantial to almost perfect intra-rater reliability of the SFMA (kappa, % agreement) was observed for all raters using the categorical scoring tool (rater A: .83, .91; rater B: .78, .88; and rater C: .72, .85). The criterion checklist scoring tool yielded intra-rater ICCs (3,1; 95% confidence interval) ranging from good to poor with rater A demonstrating the highest reliability (ICC [SEM]) (.52 [2.36]) and rater C the lowest reliability (.26 [3.42]). Inter-rater reliability of the categorical scoring tool was slight to substantial (.41-.61, .69-.79) while the criterion checklist tool (ICC 2,1) demonstrated unacceptable inter-rater reliability when assessed in all raters together (.43 [2.7]).

Conclusions: As hypothesized, intra-and inter-rater reliability of categorical scoring and criterion checklist scoring of the ten fundamental movements of the SFMA was higher in raters with greater experience.

Key Words: Functional movement, reliability, Selective Functional Movement Assessment (SFMA)

1

The Ohio State University Sports Medicine, Columbus, Ohio, USA 2 The Ohio State University Wexner Medical Center, Columbus, Ohio, USA 3 Sports Health and Performance Institute 4 Department of Orthopedics, The Ohio State University, Columbus, Ohio, USA 5 Departments of Physiology & Cell Biology, Family Medicine, Orthopaedics and Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA 6 The School of Health and Rehabilitation Science, The Ohio State University, Columbus, Ohio, USA Acknowledgements: The OSU Sports Medicine Clinical Outcomes Research Coordinator (CORC) Program provided funding for this study

CORRESPONDING AUTHOR Kathryn Glaws The Ohio State University Wexner Medical Center 2050 Kenny Road, Suite 3100 Columbus, Ohio 43221 Email: Kathryn.glaws@osumc.edu Phone: (614)293-2385 Fax: (614)293-3066

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 195

INTRODUCTION Musculoskeletal screening tools and movement based assessment models have become increasingly common in sports medicine practice as a means to identify injury risk and movement dysfunction, respectively.1,2,3 Impairments associated with musculoskeletal injuries are not often isolated to the injured joint and residual deficits can persist if these impairments are not addressed. These deficits may not be readily identifiable by traditional, joint-specific examination techniques.4 Screening and assessment tools that incorporate whole body functional movements may uncover important underlying impairments that allow for the development and implementation of targeted interventions to both maximize recovery after primary injury and prevent secondary injury.

The traditional medical model emphasizes identification of an anatomical source of pain via assessment of a tissue and/or task specific to the impaired joint.

For example, manual muscle testing and goniometric measurements isolate a specific muscle or joint in a single plane of motion.1,4 This model focuses on diagnosis of pathology versus identification of impairments and functional limitations throughout the body; thus, rehabilitation guided by the traditional medical model prioritizes symptomatic treatment of the affected tissue. The traditional model may not be optimal for the management of musculoskeletal pathology, as it does not account for ‘regional interdependence’ or the concept that adjacent anatomical regions can contribute to or be the source of a patient’s primary complaint.5 In contrast, observation of fundamental movement patterns allows for the assessment of dynamic neuromuscular control and the interaction of multiple joints and body regions. Because pain is known to alter motor control,6-11 the assessment of painful patterns of movement may be unreliable for accurate identification of the cause of a patient’s symptoms.6-11 Therefore, the observation of multi-joint fundamental movement patterns can reveal non-painful impairments in adjacent regions that may contribute to the cause of the patient’s symptoms.1,2,3 Several models have been developed to evaluate functional movement and have demonstrated good intra- and inter-rater reliability.12-19 For example, the Functional Movement Screen (FMS), is utilized widely

by health professionals to screen individuals for risk of injury via identification of asymmetries and dysfunctional movements in a healthy population. The Selective Functional Movement Assessment (SFMA) is a system developed for clinicians to identify movement dysfunction in a population with known musculoskeletal injury.12 Clinically, the SFMA begins with the evaluation of a set of fundamental movement patterns in order to identify limitations to the movements and/or symptom provocation.12 The SFMA describes movements as “functional” based on meeting specific criterion for normalcy defined for each movement.12 If a movement pattern is deemed functional and nonpainful, then further investigation of that pattern is not recommended. Painful movement patterns are further assessed with caution, as pain is known to alter motor control6-11 and continued active movement in painful patterns could exacerbate symptoms. Alternatively, these painful movements are addressed with pain modulating therapies/modalities and are ultimately used as a reassessment to determine effectiveness of treatment, as they should become non-painful with appropriate assessment and treatment of dysfunctional non-painful regions. Movement patterns that are deemed dysfunctional and non-painful are further examined using an algorithm of additional sequential tests to reveal the specific mobility or stability impairments causing the dysfunctional pattern. 12 While the SFMA is becoming a common assessment tool used by trained clinicians to identify dysfunctional movement patterns and musculoskeletal impairments, to date there is no published study that has examined its reliability. The purpose of this study was to determine the intra- and inter-rater reliability of the fundamental movement patterns of the SFMA in a healthy population, using both the categorical scoring tool and criterion checklist scoring tools, in raters with various levels of experience.

It was hypothesized that both the categorical and criterion checklist scoring tools would demonstrate higher intra-rater and inter-rater reliability in raters with more experience using the SFMA. METHODS Participants Thirty-nine healthy subjects (N = 39, 27 males, 12 female; 22.9 years +/- 1.9) were enlisted via conve-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 196

nience sampling and consisted primarily of physical therapy students and the Ohio State University Club Rugby team. Potential participants were excluded if they had undergone orthopedic surgery within the last 6 months, were currently pregnant, recorded any positive marks on the Physical Activity Readiness Questionnaire (PAR-Q) health assessment, or were under the age of 18. Neurologic conditions, specifically concussions, were not a part of the exclusion criteria; however, none of the subjects reported active neurologic or concussive symptoms at the time of testing. All subjects provided written informed consent prior to study participation.

Procedures Each participant was video recorded while performing the fundamental movement patterns of the SFMA, which consisted of ten movements: 1) Cervical Flexion, 2) Cervical Extension, 3) Cervical Rotation, 4) Upper Extremity Pattern One (behind the back internal rotation), 5) Upper Extremity Pattern Two (behind the back external rotation), 6) Multisegmental Flexion, 7) Multi-segmental Extension, 8) Multi-segmental Rotation, 9) Single Leg Balance, and 10) Overhead Deep Squat (Appendix A). All motions were performed bilaterally when applicable. The subjects were not informed of the grading criteria and were given only minimal cueing for the tasks to avoid influencing the subjectâ&#x20AC;&#x2122;s preferred movement pattern. The test administer, a physical therapist with eight hours of didactic SFMA training, provided a demonstration of each movement prior to completion of the task. Subjects were instructed to raise a red index card if pain was present so that this was clear to the raters during evaluation. Raters were not present during this process.

Two-dimensional (frontal and sagittal view) video data was captured at 30 frames per second at 640x480 resolution using two webcams (LifeCam Studio 1080p, Microsoft Corp, Redmond, WA) while connected to a PC running Cortex motion analysis software (v4.0, Motion Analysis Corp, Santa Rosa, CA) to record and automatically name each trial as each subject performed the ten fundamental movements of the SFMA. The tasks were either performed at Position 1 (distance from sagittal plane camera = 2.1 meters and frontal plane camera = 1.8 m) or Posi-

tion 2 (distance from sagittal plane camera: 3.3 m, distance from frontal plane camera = 3.7 m). Two planes of video were required to document the quality of movements and positions were selected to ensure adequate viewing for the raters as it would be observed in clinical practice.

Evaluation Raters: Three raters with varying levels of experience participated in this study. Rater A was a SFMA instructor, had attended over 100 hours of continuing education courses as an instructor and student, and had used the system extensively in the clinic for 3 years. Rater B had approximately 25 hours of education and 6 months of clinical use with the SFMA and rater C had 8 hours of education and was considered a novice with regard to clinical use of the system.

Neither rater B nor rater C had taken a formal SFMA continuing education course. Education hours represented the amount of time each rater spent under supervision of a SFMA instructor learning the entire SFMA, including individual breakouts and interventions, and were not limited to the evaluation of the 10 fundamental movements that were assessed during this study.

Raters were not present during the data collection and later individually evaluated each video using two scoring sheets: (1) the categorical scoring sheet provided by the developers of the SFMA and (2) a 34 point criterion checklist scoring tool included in the SFMA manual (Appendices B and C). Scoring possibilities on the categorical score sheet included: FunctionalNon-painful (FN), Functional-Painful (FP), Dysfunctional-Non-painful (DN), and Dysfunctional-Painful, (DP). The raters were not given any instructions or restrictions regarding the number of times to watch each video nor were they prohibited from pausing the video at any time. Evaluators repeated the scoring process for intra-rater reliability between seven and fourteen days following the initial assessment.

Rater Scoring Categorical Scoring: Raters scored each fundamental movement as FN, FP, DN or FP. Criteria for each of these scores are not included on the categorical scoring tool and therefore were not available for use during scoring. (Appendix B)

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 197

Criterion Checklist Scoring: The raters viewed each trial and assigned an ordinal scale rating to each fundamental movement task. A total score of zero was considered perfect technique without compensation while a score of 34 represented the failure of all criteria. Cumulative scores (0-34) from each rater for each subject were used for all statistical analysis (Appendix C). Prior to statistical analysis, the data were compiled and coded by a researcher not involved in rating.

It is important to note that the two scoring tools used nearly identical rating methods, which are taught as a part of the SFMA continuing education course.

The major difference between the tools is that the criterion-checklist requires raters to identify specific criteria that are not met and provides a numerical score. Additionally, the criterion-checklist lacks items regarding quality of the movement and instead focuses on quantitative aspects.

Statistical Analysis Categorical Scoring: The evaluators’ composite results were compared within raters and between raters (AB, A-C, B-C) using both absolute agreement and the kappa coefficient based upon the categorical classification of each movement. These analyses are standard in similar studies.3 Kappa coefficients were used to quantify strength of agreement. Interpretation of the Kappa coefficient has been described as: ≤0 = poor, .01-.2= slight, .21-.4= fair, .41-.6= moderate, .61-.8= substantial, .81-1.0= almost perfect.20,21 Kappa coefficients were calculated using Microsoft Excel 2010.

Criterion Checklist Scoring: A mean composite score for trial one and trial two was calculated for each rater’s data. Intra- and inter-rater reliability were assessed using Intra-class Correlation Coefficients (ICCs) with 95% confidence intervals (CI) and Standard Error of Measurement (SEM) calculated on the composite scores of each subject. Data were compared between raters (ICC [2,1]); and within each rater over the two scoring sessions (ICC [3,1]). Interpretation of reliability results were based on the following criterion: ICC >0.75= good, 0.50- 0.74 = moderate, and < 0.50 = poor.22 Inter-rater reliability, using ICC (2,1), was calculated during trial one only between all three raters collectively and between each rater (A-B, A-C, B-C).

Reliability analyses with ICCs were performed using SPSS 17.0 (SPSS Inc., Chicago, IL).

RESULTS A total of thirty-nine (39) subjects met the inclusion criteria; however, data from 35 (24 males, 11 females) of these subjects were used in the final statistical analyses as a result of data errors in four subjects due to equipment malfunction or video file corruption. None of the subjects experienced pain when completing the fundamental movements. When using the categorical tool, subjects were scored as FN most frequently when performing (1) cervical rotation to the left, (2) upper extremity pattern two – left and (3) upper extremity pattern two – right (Table 1). Evaluators scored subjects as DN most often when completing the overhead deep squat and multi-segmental rotation right and left, respectively. Rater B reported the highest total number of dysfunctional patterns, followed by rater A and rater C when using the categorical scoring tool. Rater B also demonstrated the most DN ratings per subject (mode: rater A= 7, rater B= 9, rater C= 7). When using the criterion checklist, rater A reported the highest average score using the criterion-based scoring tool in both trials, followed by rater B and rater C, respectively (Table 2).

Categorical Scoring Reliability: Substantial to almost perfect intra-rater reliability of the composite scoring of the SFMA (kappa, % agreement) was observed for all raters. Rater A demonstrated the highest intrarater reliability (.83, .91), followed by rater B (.78, .88). Rater C demonstrated the lowest intra-rater reliability (.72, .85) (Table 3). Inter-rater reliability of composite scoring was interpreted as slight to substantial. The two raters with the most experience, rater A and B, demonstrated the highest inter-rater reliability (.76, .88). Rater A and rater C demonstrated fair inter-rater reliability (.30, .74) and raters B and C, the least experienced raters, demonstrated the lowest inter-rater reliability (.20, .62). (Table 4) Intra-rater reliability of each of the component fundamental movements varied between raters. Rater A showed the highest range of kappa values followed by rater B and rater C, respectively (.41-.94, .34.89). (Table 5) The most experienced rater demonstrated the highest intra-rater reliability with single

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 198

Table 1. Frequency of Functional/Non-painful vs Dysfunction/Non-Painful Ratings, Categorical Scoring

Table 2. Mean of Total Score, Criterion Checklist Scoring

Table 3. Intra-rater Reliability, Categorical Scoring

Table 4. Inter-rater Reliability,Categorical Scoring (Trial 1)

leg stance on the left (kappa=.94) and the lowest with left cervical rotation (.41). Rater B showed the highest intra-rater reliability with upper extremity pattern two on the right (.89) and the lowest with

upper extremity pattern one on the right (.34). Rater C demonstrated the highest and lowest intra-rater reliability when scoring the single leg stance on the left (.76) and multi-segmental extension (.25), respectively.

Inter-rater reliability of the component fundamental movements was lower than intra-rater reliability (Table 6). Raters A and B demonstrated the highest range of kappa values (.07-.79) followed by raters A and C (.18-.62) and raters B and C (-.31-.68), respectively. Raters A and B demonstrated the highest inter-rater reliability with multi-segmental rotation to the right (.79). The movement with the lowest inter-rater reliability was upper extremity pattern one on the right evaluated by the least experienced raters (-.31).

Criterion Scoring Reliability: Intra-rater ICCs (3, 1) ranged from good to poor, with rater A having the highest reliability with the smallest SEM (ICC, SEM) (.86, 1.2), followed by rater B (.71, 1.7) and C (.59, 2.2) respectively (Table 7). The two most experienced raters (raters A and B) had the highest inter-rater reliability within both trials (.68 and .52, respectively), interpreted as moderate reliability. The least experienced rater, rater C, demonstrated poor inter-rater reliability with the other two raters in trials one (.40 and .31) and two (.26 and .34) (Tables 8 and 9), while

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 199

Table 5. Intra-Rater Reliability, Categorical Scoring: Component Fundamental Movements

also demonstrating the lowest intra-rater reliability (.59). Inter-rater reliability of trial one was found to be poor when assessed in all raters together (.43) (Table 8).

DISCUSSION The purpose of this study was to investigate the intra-rater and inter-rater reliabilities of the SFMA in raters with varying experience levels. The current findings show that intra-and inter-rater reliability of categorical scoring and criterion checklist scoring of the fundamental movements of the SFMA were reflective of level of experience, which supported the a priori hypothesis. Specifically, fundamental SFMA movement scoring demonstrated substantial to excellent intra-rater reliability when using the categorical scoring tool but poor to good intra-rater reliability when using criterion-based scoring tool.

Substantial and moderate inter-rater reliability was found for more experienced users with categorical and criterion scoring, respectively, while poor reliability was found for least experienced rater.

Table 6. Inter-Rater Reliability, Categorical Scoring: Component Fundamental Movements

Table 7. Intra-rater Reliability, Criterion Checklist Scoring

Table 8. Inter-rater Reliability, Criterion Checklist Scoring (Trial 1)

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 200

Table 9. Inter-rater Reliability, Criterion Checklist Scoring (Trial 2)

The reliability data presented here are similar to that observed in reliability studies examining other movement-based screening and assessment systems. Rater A, who had significantly more experience compared to the other raters and is also a SFMA instructor, demonstrated the best intra- and inter-rater reliabilities using both scoring tools, followed by raters B and C, respectively. Novice raters of the Functional Movement Screenâ&#x201E;˘ show poor to good reliability while experienced raters show good to excellent reliability.13,14,15 In addition, the inter-rater reliability between novice and expert raters of the Landing Error Scoring System (LESS) and the drop jump landing for ACL risk were shown to range from moderate to excellent and good to excellent, respectively.23,24 In sum, these data indicate that clinical screening tools are most reliability implemented by experienced users; however, the amount of training necessary to maximize intersession reliability of the SFMA is unknown.

While total categorical and criterion scoring methods indicated moderate intra- and inter-rater reliability, some patterns were less reliable than others.

Multi-segmental extension and upper extremity pattern one demonstrated slight to fair inter-rater reliability between all raters when categorical scoring was used. Intra-rater reliability of multi-segmental extension was also fair for the two least experienced raters, while the most experienced rater demonstrated almost perfect reliability. Evaluation of both multi-segmental extension and upper extremity pattern one require assessment of qualitative criterion including the presence or absence of a uniform spinal curve and scapular dyskinesia, respectively. These criteria may be more difficult to assess compared to criterion associated with specific landmarks. Experienced raters likely have increased familiarity viewing the fundamental movements and with the rating

criteria, which may allow them to more reliably score each movement. In addition, results from this study may indicate a trend for experienced raters to be more stringent using the criterion checklist scoring tool. For example, rater A averaged four more errors per subject than rater C. As a result of viewing more fundamental movements, experienced raters may have a higher benchmark for scoring functional particularly when evaluating qualitative aspects.

While the criterion checklist model demonstrated poor to moderate inter-rater reliability between examiners of different experience, intra-rater reliability of the experienced rater was good. The format of this tool, specifically the inclusion of listed criteria and a numerical score, lends itself to potential use as a clinical outcome tool. This scoring method produces ordinal data, in contrast to the categorical scoring method, which allows for increased objectivity and ease of tracking. Data from this preliminary study highlights the reliability of the SFMA in the hands of an experienced user; however validation and responsiveness to change in a clinical population must be determined prior to use of the SFMA as an outcome tool.

Evidence-based clinical implementation of the SFMA categorical scoring tool requires validation for its use in identifying dysfunction. Plich et al performed a correlational study to determine whether the SFMA related to the self-reported outcomes in patients treated for neck or low back conditions.25 The reported results showed a significant relationship between the scores of the Neck Disability Index and the criterion scoring tool, thus establishing a preliminary positive relationship between patientsâ&#x20AC;&#x2122; self-reported outcomes and the SFMA.25 Residual musculoskeletal impairments following injury and supervised rehabilitation are common and may increase an individualâ&#x20AC;&#x2122;s risk for a second injury.26-30 These impairments often are not isolated to the injured joint and can be missed by traditional, joint-specific examination techniques. Decreased hip mobility in golfers with low back pain31 and decreased core and proximal hip control in overhead athletes with shoulder pain 30,32 are just a few examples of these regionally related impairments associated with primary injury. Similar regional impairments have been associated with secondary injury. Deficits

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 201

in postural stability and proximal hip control in the transverse plane were among four factors found to be predictive of secondary ACL injury.27 Use of the SFMA may provide a more comprehensive understanding of the mobility and stability impairments throughout the body than the traditional medical model, and subsequently may aid the development of targeted interventions to maximize recovery after primary injury. Ultimately, resolution of total body impairments following primary injury may help to decrease risk of a re-injury or a secondary injury.

There are limitations to this study. Video recording does not mimic the clinical setting, where the patient can be viewed from multiple angles, receive verbal clarification, or be palpated to determine if grading criteria have been met. However, the use of video assessment has been used in similar reliability studies and limits external variability.13 Second, while the criterion checklist scoring tool is included in the SFMA handbook this tool is not commonly utilized and none of the raters had prior experience with the tool. This is the first study to evaluate the reliability of the SFMA, but its validity has not yet been examined. The raters in this study retrospectively reported that the criteria on the checklist were not fully inclusive of movement impairments they would have scored as an impairment necessitating further evaluation. For example, failing criteria listed on the criterion checklist for the Overhead Deep Squat movement did not include lifting of the heels during the action, but this would be deemed compensatory or dysfunctional per the categorical scoring criteria. In addition, criteria did not fully account for qualitative aspects of the movements that may be observed during UE patterns (such as scapular dyskinesis) or differences in perceived exertion during bilateral movements, further highlighting that refinement of the tool may also be necessary.

Finally, the SFMA was developed for use on a clinical population, whereas this study examined healthy participants, thus limiting its external validity.

Future research should focus on determination of the reliability of raters with similar experience and rating experience, which may help determine the minimum education and experience required to establish adequate agreement of the scoring for the

SFMA during clinical use. Additional research is also necessary to determine the reliability of the categorical and criterion checklist scoring of the SFMA in a clinical population, as this is the target population for which this screening system was designed. Finally, validation of both the categorical scoring tool for clinical use and the criterion checklist scoring tool for potential use as an outcome tool would support the implementation of the SFMA in clinical populations.

CONCLUSION Scoring of the ten fundamental movements of the SFMA, using the categorical and criterion checklist model in a healthy population, is most reliable between sessions when performed by a single experienced rater. Future research should focus on the determination of the reliability and validity of the SFMA in a population with known musculoskeletal injury, as this is the population for which this assessment system is intended.

REFERENCES 1. Cook G, Burton L, Hoogenboom B. Pre-participation screening: The use of fundamental movements as an assessment of function- Part 1. N Am J Sports Phys Ther. 2006;1(2):62-72.

2. Kiesel K, Plisky PJ, Voight ML. Can serious injury in professional football be predicted by a preseason functional movement screen? N Am J Sports Phys Ther. 2007;2(3):147-158.

3. Schneiders A, Davidsson A, Horman E, Sullivan SJ. Functional Movement Screen Normative Values in a Young, Active Population. Int J Sport Phys Ther.

2011;6(2):75-82.

4. Holzbaur R, Murray W, Delp S. A Model of the Upper Extremity for Simulating Musculoskeletal Surgery and Analyzing Neuromuscular Control. Ann Biomed Eng. 2005;33(6):829-840.

5. Wainer R, Whitman J, Cleland J, Flynn T. Regional Interdependence: A Musculoskeletal Examination Model Whose Time Has Come. .J Orthop Sports Phys Ther. 2007;37(11):658-660.

6. Dickx et al. “The effect of unilateral muscle pain on recruitment of the multifidus during autonomic contraction. An experimental pain study.” Manual Therapy. 2010; 15(4):364–369.

7. Ferreira PH, Ferreira ML, Hodges PW. “Changes in recruitment of the abdominal muscles in people with low back pain: ultrasound measurement of muscle activity.” Spine. 2004;29(22):2560–2566.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 202

8. Hodges PW, Richardson CA. “Altered trunk muscle recruitment in people with low back pain with upper limb movement at different speeds.” Arch Phys Med Rehabil. 1999;80(9):1005–1012.

9. Hodges PW, Tucker K. “Moving differently in pain: a new theory to explain the adaptation to pain. Pain.

2011;152:S90-98.

10. Kiesel et al. “Experimentally induced pain alters the EMG activity of the lumbar multifidus in asymptomatic subjects.” Manual Therapy.

2012;17(3):236–240.

11. Kiesel KB, Uhl T, Underwood FB, Nitz AJ. “Rehabilitative ultrasound measurement of select trunk muscle activation during induced pain.”

Manual Therapy. 2008;13(2):132–138.

12. Cook, G. Movement: Functional Movement Systems: Screening, Assessment, and Corrective Strategies.

On Target Publications. Santa Cruz, CA. 2010.

13. Gribble P, Brigle J, Pietrosimone B, Pfile K, Webster K. Intrarater reliability of the Functional Movement Screen. J Strength Cond Res. 2013;27(4):978-81.

14. Minick K, et al. Interrater reliability of the functional movement screen. J Strength Cond Res. 2010;24(2):479-86.

15. Smith CA, Chimera NJ, Wright NJ, Warren M. Interrater and intrarater reliability of the functional movement screen. J Strength Cond Res. 2013;27(4):982-987.

16. Teyhen D, et al. The Functional Movement Screen: A Reliability Study. J Orthop Sports Phys Ther: 2012;42(6). 530-540.

17. Harris-Hayes M, Van Dillen L. “The inter-tester reliability of physical therapists classifying low back pain problems based on the movement system impairment classification system.” PM&R. 2009; 117-126.

18. Sahrmann S. Movement system impairment syndromes of the extremities, cervical and thoracic spines. Elsevier Health Sciences, 2010.

19. Trudelle-Jackson E, Sarvaiya-Sjaj S, Wang S. Interrater reliability of a movement impairmentbased classification system for lumbar spine syndromes in patients with chronic low back pain.

J Orthop Sports Phys Ther. 2008;38(6):371-376.

20. Landis, J.R., Kock, G.G. The measurement of observer agreement for categorical data. Biometrics.

1977;33:159-174.

21. Sim J, Wright C. The kappa statistic in reliability studies: use, interpretation, and sample size requirements. Phys Ther. 2005;85:257-268.

22. Portney LG, Watkins MP. Foundations of Clinical Research: Applications to Practice. 2nd ed. Up- per Saddle River, NJ: Prentice Hall;2000.

23. Padua et al. Reliability of the Landing Error Scoring System-real time, a clinical assessment tool of jumplanding biomechanics. J Sport Rehabil. 2011;20(2): 145-156.

24. Ekegren et al. Reliability and validity of observational risk screening in evaluating dynamic knee valgus. J Orthop Sports Phys Ther.

2012;39(9):665-674.

25. Plich SB, et al. Relationship Among Performance on the Selective Functional Movement Assessment and NDI and ODI Scores in Patients with Spine Pain.

Orthopaedic Practice. 2013;24(1):12.

26. Greene HS, Cholewicki J, Galloway MT, Nguyen CV, Radebold A. A history of low back injury is a risk factor for recurrent back injuries in varsity athletes.

Am J Sports Med. 2001;29(6):795-800.

27. Hewett TE, Di Stasi SL, Meyer GD. Current concepts for injury prevention in athletes after anterior cruciate ligament reconstruction. Am J Sports Med. 2013;41(1):216-24.

28. Paterno MV, Schmitt LC, Ford KR, Rauh MH, Myer GD, Huang B, Hewett TE. Biomechanical measures during landing and postural stability predict second anterior cruciate ligament injury after anterior cruciate ligament reconstructions and return to sport. Am J Sports Med. 2010;38(10):1968-1978.

29. Orchard JW. Intrinsic and extrinsic risk factors for muscles strains in Australian football. Am J Sports Med. 2001;29(3):300-303.

30. Zazulak BT, Hewett TE, Reeves NP, Goldberg B, Cholewicki J.Deficits in neuromuscular control of the trunk predict knee injury risk: a prospective biomechanical-epidemiologic study. Am J Sports Med. 2007;(7):1123-30.

31. Vad VB et al. Low back pain in professional golfers: the role of associated hip and low back range-ofmotion deficits. Am. J. Sports Med. 2004;32(2):494-497.

32. Burkhart S, Morgan C, Kibler B. Shoulder Injuries in Overhead Athletes. Clin Sport Med. 2003;19(1): 125-158.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 203

Appendix A. FUNDAMENTAL MOVEMENTS: “Please remove your shoes for all activities. I will perform each exercise and give you instructions. Please let me know if you have any pain with any of the activities.” (If the subject performs any movements incorrectly, please provide cueing at your discretion for instructional aid.)

Active Cervical Flexion: “Stand in a tall position with feet together and toes pointing forward.”

-“Please bring your chin down to your chest with your body upright.”

Active Cervical Extension: “Stand in a tall position with feet together and toes pointing forward.”

-“Please look up to the ceiling.”

Cervical Rotation Side-Bend: “Stand in a tall position with feet together and toes pointing forward.”

-“Please turn your head as far as you can to the right/left and then bend down and touch your chin towards your collarbone.” (Note: Avoid shoulder elevation) Upper Extremity Pattern 1-Medial Rotation Extension: “Stand in a tall position with feet together and toes pointing forward.”

-“Take your Right/Left arm and reach behind your back and aiming to touch the bottom of your opposite shoulder blade.”(Note: scapular dyskinesis) Upper Extremity Pattern 2-Lateral Rotation Flexion: “Stand in a tall position with feet together and toes pointing forward.”

-“Take your Right/Left arm and reach up and behind your head towards the top of your opposite shoulder blade.” (Note: scapular dyskinesis)

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 204

Appendix A. (continued)

Multi-segmental Flexion: “Stand in a tall position with feet together and toes pointing forward.”

-“Please bend down and try to touch your toes.” (Note: knees straight) Multi-segmental Extension: “Stand in a tall position with feet together and toes pointing forward.”

-“Please keep your hands above your head and reach back as far as you can.”

(Note: knees straight)

Multi-segmental Rotation: “Stand in a tall position with feet together and toes pointing forward.”

-“Please place your hands by your side and rotate your entire body Right/Left trying to look behind you while keeping your feet still.”

Single Leg Stance (eyes open, then closed): “Stand in a tall position with feet together and toes pointing forward.”

-“1. Lift your Right/Left leg so that your hip and knee make 90 degree angles.

Please hold this for 10 seconds. 2. Now lift your leg to the same 90 degree position and then close your eyes. Hold this position for 10 seconds.”

Overhead Deep Squat: “Please start by placing feet shoulder width and toes pointing forward.”

-“Please place your arms over your head and move them slightly outside your shoulders with your elbows straight. Hold this position and squat down as far as you can towards the floor.” (Note: subject should squat back and down, not over toes.)

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 205

Appendix B.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 206

Appendix C.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 207

IJSPT

CASE REPORT

REHABILITATION OF A 23YEAROLD MALE AFTER RIGHT KNEE ARTHROSCOPY AND OPEN RECONSTRUCTION OF THE MEDIAL PATELLOFEMORAL LIGAMENT WITH A TIBIALIS ANTERIOR ALLOGRAFT: A CASE REPORT Scott Cheatham, PT, DPT, PhD [c], OCS, ATC1 Morey J. Kolber, PT, PhD, OCS, Cert MDT, CSCS2 William J. Hanney, PT, DPT, PhD3

ABSTRACT Background: Patellar dislocations are traumatic injuries that occur most often in individuals under the age of twenty and are related to sports and physical activity. Currently, there are no published reports describing the rehabilitation of younger males after arthroscopy and open reconstruction of the medial patellofemoral ligament (MPFL) using a tibialis anterior allograft.

Case Description: The subject of this case report was a 23 year-old recreational male athlete who underwent right knee arthroscopic patellar chondroplasty, lateral retinacular release, partial lateral menisectomy, and an open MPFL reconstruction with a tibialis anterior allograft after sustaining a second patellar dislocation. The purpose of this case report is to present the functional outcomes as well as the rehabilitation strategy used during the treatment of this athlete.

Outcome: The patient returned to his prior level of activity after finishing 22 weeks of physical therapy. At a one-year follow-up, the patient reported pain-free physical activity including weight training, running, and recreational basketball.

Discussion: The results of this four-phase rehabilitation program with this subject were excellent. However, research beyond single subject case reports on post-operative rehabilitation for knee arthroscopy and open MPFL reconstruction with a tibialis anterior allograft is lacking. This is the first report that describes a rehabilitation strategy for this procedure. Although there was a successful rehabilitation outcome, future research is necessary to establish optimal rehabilitation guidelines as well as normative milestones for individuals who undergo this surgery.

Key Words: Patellofemoral; ligament; dislocation; instability; rehabilitation Level of Evidence: 4-Case Report

1

California State University Dominguez Hills, Carson, CA, USA. 2 Boca Raton Orthopaedic Group, Boca Raton, FL, USA 3 University of Central Florida, Orlando, FL, USA

CORRESPONDING AUTHOR Scott Cheatham, PT, DPT, PhD©, OCS, ATC, CSCS Assistant Professor Director Pre-Physical Therapy Program Division of Kinesiology and Recreation, SAC 1138 California State University Dominguez Hills 1000 E. Victoria St. Carson, CA 90747 office # (310) 243-3794 E-mail: Scheatham@csudh.edu

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 208

BACKGROUND Patellar dislocations occur mostly in younger individuals under the age of twenty and are often related to sports and physical activity.1,2 Dislocations occur as a result of trauma whereby the patella travels out of the normal position in the patellofemoral (trochlear) groove. Often, a dislocated patella does not spontaneously return to normal position in the trochlea, in contrast to a subluxed patella where the patella may only partially travel out of the groove.3 Lateral patellar dislocations (patella slips over lateral groove) are the most common type of patellar dislocations and may result in damage to the medial patellofemoral ligament (MPFL), medial retinaculum, vastus medialis oblique, and the articular cartilage of the patella and trochlea.3 Dislocations typically occur from direct trauma to the patella or a sudden twist of the slightly flexed knee during weight bearing activity.4 Acute patellar dislocations account for about 3% of all knee injuries and are the second highest cause of knee hemarthrosis.5 The highest incidence of patellar dislocations is in females 10 to 17 years of age.6 It has been reported that the initial diagnosis of a patellar dislocation is often overlooked by as much as 45 to 73% of cases.3 Without advanced imaging, the clinical diagnosis is often elusive, outside of recognizing patellar instability.7-9 Individuals with a prior history of dislocation are seven times more likely to experience episodes of patellar instability than first time dislocators.6 A search of the literature reveals no consensus on the number of dislocations that qualify as “recurrent” or “frequent”.

Primary and recurrent dislocations can be linked to several predisposing factors including: patella alta, increased quadriceps angle, trochlear dysplasia (hypoplasia), vastus medialis oblique atrophy, MPFL insufficiency, increased patellar tilt, genu recurvatum, increased femoral anteversion, external tibial torsion, foot pronation, and patellar hypermobility.5,10,11 Operative versus non-operative management of patellar dislocations remains under debate due to the lack of high quality evidence that confirms any difference between the approaches.5,11,12 Acute surgical indications include osteochondral fragments, persistent patellar dislocation and subluxations, detachment of the medial retinaculum and vastus medialis

oblique from the medial patella. Surgical indications for patients with chronic instability involve addressing the predisposing factors that affect patellar function such as MPFL insufficiency.10 The ideal candidate for surgery is an individual that seeks medical care for recurrent instability with minimal pain or patellofemoral pain that is directly related to the episodes of instability.13 The non-operative management of patellar dislocations may not always be successful with recurrent dislocation rates reported in up to 44% and the incidence of chronic instability being greater than 50% in individuals with a history of one or more patellar dislocation.5 This may be due to the disruption of the MPFL, which has been found to provide 50 to 60% of the restraining force against lateral patellar translation especially between 20 to 30 degrees of knee flexion.14-16 Clinically, it has been found that the MPFL is disrupted to varying degrees in 94 to 100% of first time patellar dislocations and that damage to the MPFL has been shown to be a predictor of recurrent dislocations.1,4,17 Several authors have described positive outcomes for surgical reconstruction of the MPFL in individuals who experienced recurrent dislocations.18,19,20 Nelitz et al18 demonstrated significant improvement (P<.01) on the visual analog scale (VAS), the Kujala knee function scale, and the International Knee Documentation Committee (IKDC) scale after reconstruction of the MPFL using a gracilis tendon autograft in a group of 21 patients (mean age 12.2 years) with an average 2.8 year follow-up. No recurrent dislocations occurred in the group but two patients with high grade trochlear dysplasia retained the presence of an apprehension sign. Other authors have found similar positive outcomes using hamstring allografts and autografts with no incidence of redislocations after MPFL reconstruction.19,20 Despite this recent evidence, long-term outcomes are still needed to further confirm the efficacy of this procedure.

A search of the literature in PubMed, CINAHL, ProQuest and Google Scholar® revealed two clinical commentaries regarding non-surgical interventions,21,22 one commentary on non-specific post-surgical rehabilitation,23 a case report on post-operative care after MPFL hamstring allograft,24 a case report on post-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 209

operative care after trochleoplasty,25 and two systematic reviews on post-operative rehabilitation,26,27 Currently, to the author’s knowledge, there are no published reports describing the post-operative rehabilitation for open repair of the MPFL using a tibialis anterior allograft. Due to the paucity of literature, a detailed description of the proposed rehabilitation for use after this surgical procedure is necessary.

The purpose of this case report is to present the outcomes and rehabilitation strategy used for a 23 yearold male who underwent right knee arthroscopic patellar chondroplasty, lateral retinacular release, partial lateral menisectomy, and open MPFL reconstruction with a tibialis anterior allograft.

CASE DESCRIPTION The patient participated in high school football (e.g. offensive lineman position) and suffered his first right knee injury during his junior year. During practice, the patient suffered a non-contact knee injury. He planted and twisted his knee resulting in immediate pain and swelling. The patient saw an orthopedic surgeon and was subsequently referred for a magnetic resonance imaging (MRI) scan without contrast which indicated a peripheral tear of the anterior horn of the lateral meniscus and damage to the medial retinaculum which was consistent with a transient lateral dislocation of the patella. The patient underwent non-surgical management for 6-weeks with physical therapy which included wearing a Palumbo® (Palumbo, Inc. Irving, TX) patellar stabilizing brace during physical activity. The patient was able to resume sports participation and physical activity without additional incidences of dislocation. Approximately 7 years later, the patient suffered a second patellar dislocation when he collided with another player during a recreational basketball game. The patient saw an orthopedic surgeon and was subsequently referred for a MRI scan without contrast which indicated signs of a prior transient patellar dislocation with persistent subluxations of the patella, including trabecular bone injury of the lateral femoral condyle, and a shallow trochlear groove (Figure 1). Based upon the results of the MRI and clinical findings the patient elected to undergo surgical intervention.

In July 2012, the patient underwent right knee ar– throscopic patellar chondroplasty, lateral retinacular release, partial lateral menisectomy, and open MPFL

Figure 1. MRI of right knee.

reconstruction with a tibialis anterior allograft. The patient did not undergo a trochleoplasty for his shallow trochlear groove, which is an emerging procedure that is often combined with repair of the MPFL in patients with trochlear dysplasia.28 Researchers have reported incidences of post-operative patellar instability and dislocations in patients with moderate to severe trochlear dysplasia who underwent repair of the MPFL without trochleoplasty.29-31 INITIAL EXAMINATION The patient was seen in physical therapy for the initial examination approximately two weeks after surgery.

The patient was a healthy 23 year-old male with a mixed endomorphic-mesomorphic build (Body mass135.17 kg, Height-182.88 cm, Body Mass Index- 40.4).

The patient reported no symptoms of patellar instability and was taking Voltaren® (50 mg) and Norco® (7.5 mg/325 mg) for pain control, as needed. The patient ambulated with a knee brace locked at 0°, full weight bearing with axillary crutches. Precautions restricted the patient from flexing his knee beyond 90 degrees for the first 4 weeks post-operatively, which was based upon the surgeon’s preferential guidelines versus a biomechanical explanation. Researchers have found that the MPFL has a primary role of guiding the patella in the trochlear groove during the first 20-30 degrees of

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 210

knee flexion.32,33 The MPFL also has an additional stabilizing role with greater knee flexion angles. Higuchi et al34 examined the non-weight bearing length change patterns of the MPFL in vivo in 20 healthy adult volunteers (10 male, 10 female) from full knee extension to a knee flexion angle of 120 degrees via MRI. They found that the MPFL contributes to medial stability of the patella from 0-60 degrees of flexion with the strongest strain at 60 degrees. This research provides some evidential support for the use of a post-operative ROM limitation. However, there is no consensus in the literature regarding the 90 degree flexion limitation, thus the decision was based primarily on the suggested treatment after the arthroscopic surgical procedure and associated discomfort typically experienced at higher knee flexion angles in the acute stages. The examination and subsequent interventions were carried out by a physical therapist with 10 years of experience and a board certification in orthopedics. The examination findings are outlined below.

Subjective & Observation The patient reported that his primary goals were to return to pain-free physical activity, weight training, and recreational basketball. At the time of examination, the primary complaint was knee stiffness and pain around and within the knee joint. A review of the patientâ&#x20AC;&#x2122;s history revealed no current or prior lower extremity injuries or co-morbidities that would impede rehabilitation. He denied pain or discomfort at the neighboring joints and had no reports of paresthesias or general malaise. Inspection of the incision site revealed adequate healing with the steri- strips intact over the anteromedial and anterolateral arthroscopy portals. Inspection of the medial incision site revealed an approximate 5.3 cm longitudinal incision midway between the medial femoral condyle and the patella covered with steri-strips that were intact and demonstrated adequate healing. Mild knee effusion was present upon inspection. A general static postural screen was conducted in standing which revealed right lower extremity external rotation and bilateral pes planus alignment (Figure 2). The patient confirmed wearing custom orthotics during physical activity.

Self-Report Measures An 11-point numerical pain rating scale (NPRS) with 0 (no pain) to 10 (worst pain imaginable) was used to elicit an objective ranking of the patients

Figure 2. Standing postural screen.

pain level.35,36 During the past 24 hours, the patient reported his pain to be 6/10 at worse and 1/10 at best. At the time of the examination his pain was rated as 4/10. The patient also completed the Lower Extremity Functional Scale (LEFS) to obtain a better understanding of his functional abilities.37-39 The patient scored a 13 out of 80 (16%) scaled points and reported difficulty with most activity due to his postoperative status. Both the LEFS and NPRS were used as repeated measures of function throughout the rehabilitation process.

Range of Motion and Muscle Performance The patientâ&#x20AC;&#x2122;s hip, knee, and ankle range of motion (ROM) were tested both actively and passively as described by Norkin & White.40 Bilateral measurements were within normal limits (WNL) and symmetrical with the exception of the right knee. The patient was apprehensive with movement of the right knee but agreed to perform both active range of motion (AROM) and passive range of motion (PROM). AROM of the right knee revealed flexion to 90 degrees with a 10-degree loss of knee extension. PROM revealed flexion to 90 degrees and a 5-degree loss of extension which may have been from the knee joint effusion.

Muscle performance of the lower extremities was

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 211

quantified (Table 1) using manual muscle testing as described by Hislop and Montgomery.41 The right quadriceps was measured 2+/5; however no confrontational resistance was added due to the patient’s post-operative status.

was good with the absence of a J-sign during AROM and PROM knee flexion and extension. The patellar apprehension test was also negative upon testing. A neurovascular screen of the lower extremity revealed no significant findings.

Palpation Palpation of the right knee region was assessed using a 5 point pain scale (Grade 0-4) as described

by Hubbard and Berkoff.42 The grading criterion is as follows: grade 0 - no tenderness, grade I - mild tenderness without grimace or flinch, grade II - moderate tenderness plus grimace or flinch, grade III - severe tenderness plus marked flinch or withdrawal, grade IV - unbearable tenderness, patient withdrawals with light touch.42 Palpation of the patient’s right knee revealed grade I (mild) tenderness along the quadriceps tendons, pes anserine group insertion, and distal insertion of the iliotibial band. The patient had increased walking activity with axillary crutches for several consecutive days prior to the initial examination, which may have explained the mild knee effusion and palpable tenderness.

Assessment and Evaluation At the time of the initial examination, the patient was approximately two weeks post-surgery. The examination findings revealed impairments and functional limitations that were consistent with Practice Pattern 4I from the Guide to Physical Therapist Practice: Impaired Joint Mobility, Motor Function, Muscle Performance, and Range of Motion Associated With Bony or Soft Tissue Surgery,43 It was determined that the patient would benefit from a structured rehabilitation program to improve impairments and address functional limitations.

Special Testing Muscle length testing was performed to determine the nature of the patient’s extension loss and revealed length impairments of both the gastrocnemius and hamstrings. Muscle length testing was deferred at the quadriceps due to the post-operative movement restrictions. Observed patellar tracking

INTERVENTION PLAN Plan of Care The rehabilitation program (Table 2a, 2b) was based on a four-phase protocol, which was designed using clinical experience and collaboration with the patient’s orthopaedic surgeon. Due to the paucity of rehabilitation literature for MPFL repair, the authors followed a phased structure similar to those reported in the descriptive literature.23,24,25 Trunk stabilization and general lower kinetic chain exercises were integrated into the program consistent with the regional interdependence model.44

Table 1. Muscle Performance Testing.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 212

Table 2a. Rehabilitation Program: Phase I and Phase II

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 213

Table 2b. Rehabilitation Program: Phase III and Phase IV

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 214

POST-OPERATIVE REHABILITATION Phase I The focus of Phase I was to protect the surgical site, restore AROM and PROM, control pain and inflammation, restore normal gait without an assistive device, and improve neuromuscular control and muscle performance. Phase I began two weeks postoperatively and was based on the specific guidelines from the surgeon and collaboration with the evaluating physical therapist (Table 2a). Recommended precautions included: avoid pivoting or twisting the knee, limiting knee flexion to 90 degrees for the first four weeks, use of axillary crutches with brace locked to 0° during ambulation until adequate quadriceps control is appreciated, and to avoid undue pain and stress to the surgical site. For the purposes of this case report the authors defined surgical site stress as symptoms of pain or signs of effusion after therapeutic exercise.

During Phase I, care was taken to protect the surgical site and limit knee ROM based on the surgeon’s preference. Also, the patient was closely monitored for any bouts of instability. Closed chained activity was closely monitored especially with ranges from 0 to 30° of knee flexion since the trochlear groove is a major stabilizer for the patellofemoral joint at those ranges.45 Manual therapy included grade I and II superior and inferior patellar glides. Medial and lateral joint glides were not performed in order to avoid stressing the surgical site. During the first week, neuromuscular electrical stimulation (NMES) was used in conjunction with isometrics for muscle re-education (50 pulses per second, 10 seconds on, 30 seconds off).46,47 Interferential electrical current (IFC) with ice was also used for pain control and to prevent post exercise swelling (using IFC preset protocol for pain and swelling for 15 minutes), as needed.48,49 The patient’s home exercise program included pain-free AROM and PROM to 90 degrees of flexion for the first four weeks, basic lower extremity strengthening and avoidance of open kinetic chain activity at the knee in order to protect the surgical site.45 The patient was weaned off crutches after two weeks and ambulated with his brace unlocked at four weeks post-operatively. The patient was seen for physical therapy an average of two times per week.

At six weeks post-operative, the patient met the criteria to advance to Phase II which included: no signs

or symptoms of patellar instability during activities performed in Phase I, knee ROM 90° or greater, full knee extension, active quadriceps contraction, heel to toe gait pattern with unlocked brace, no assistance of crutches, and minimal to no joint effusion.

Phase II The focus of Phase II was to continue to protect the surgical site, continue to restore joint ROM, normalize his gait pattern, as well as improve muscle performance by progressing closed kinetic chain (CKC) exercises in single plane motions. Phase II began 8 weeks post-operatively which continued to include collaboration between the surgeon and the physical therapist (Table 2a). Recommended precautions included: avoid pivoting or twisting the knee, overstressing the surgical site, multiplanar movements, and closed chain movements with knee flexion angles >90 degrees, and that the patient should continue to wear the brace during activity.

Due to the patient’s clinical presentation of bilateral pes planus and considerable genu valgus angle (Fig. 2), maintaining proper lower extremity alignment during closed chain activity was stressed. Exercises focusing on the hip and abdominal core were added which have been associated with improved lower extremity function and reduction of pain in patients with patellofemoral pain syndrome.50,51 The patient also wore his custom orthotics during activity. Research suggests that foot orthoses may help reduce pain in patients with anterior knee pain thus combining therapeutic exercise and orthoses may produce better outcomes than orthoses alone.52,53 On two occasions during Phase II, IFC (as described previously) and ice were used as a result of knee discomfort following exercise.48,49 The patient’s home exercise program included Phase I and II activity and the addition of the elliptical trainer or stationary bike using moderate resistance for 20 minutes.

At 12 weeks post-operative, the patient met all criteria to advance to Phase III which included: no signs or symptoms of patellar instability during activity, adequate quadriceps strength (i.e. absence of extensor lag during straight leg raise), knee ROM 120° or greater, single leg balance 30 seconds or greater, normal gait pattern with unlocked brace, and minimal to no joint effusion.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 215

Reassessment The Lower Extremity Functional Scale (LEFS) was given again to reassess the patient’s functional abilities at this point in his rehabilitation. The patient scored a 66 out of 80 (83%) scaled points and reported difficulty with higher-level activities such as sports, hopping, and running. This was a 53-point improvement since the pre-intervention assessment (i.e. 13 out of 80 scaled points). The minimal detectable change and minimal clinically important difference is 9 scale points.39 The patient’s phase of healing and current restrictions were considered when interpreting the results. The patient reported an occasional 2/10 pain on the NPRS (local to the surgical site) after strenuous exercise and 0/10 pain with Activities of Daily Living (ADL’s). The patient’s knee range of motion was measured and found to be 2-0-123° (extension-neutral-flexion). Manual muscle testing was also conducted at this time (Table 1).

Phase III The focus of Phase III was to restore full joint ROM, muscle performance, improve proprioception, and introduce sports specific movements. Phase III began 12 weeks post-operatively (Table 2b). Recommended precautions included: avoid overstressing the surgical site, closed chain movements with deep knee flexion angles (>90 degrees), and post exercise swelling and pain.

During this phase, multidirectional CKC exercises were introduced with light jogging patterns and ladder drills. Phase III was considered a transitional phase to prepare the patient for more advanced activity in Phase IV. The patient responded well to treatment during this phase with no refractory occurrences or need for modalities. The patient’s home exercise programs included Phase I-III activities with the continuation of the elliptical and the addition of the incline treadmill for cardiovascular conditioning. At 18 weeks post-operative, the patient met all criteria to advance to Phase IV which included: no signs or symptoms of patellar instability, minimal to no joint effusion, improved quadriceps strength (i.e.; 4+/5), normal knee ROM, normal jogging pattern while wearing brace, and clearance by the surgeon.

Phase IV The focus of Phase IV was for the patient to return to full sports activity. Phase IV began 18 weeks post-oper-

ative (Table 2b). Recommend precautions included maintaining pain-free activity and avoidance of post exercise joint effusion. Criteria to return to full activity included: no signs and symptoms of patellar instability, absence of joint effusion, normal lower extremity strength, normal neuromuscular control with all sports specific testing, and clearance by surgeon.

Due to the patient’s morphological build, a custom patellar tracking brace from Breg® (Breg, Inc. Carlsbad, CA) was ordered to further protect the surgical site during sports activity (Figure 3A, 3B). During Phase IV, multidirectional sports specific activity was progressed with the introduction of the Prevent Injury and Enhance Performance (PEP) program, which has been shown to reduce incidents of lower extremity injury in younger males and females.54 The patient responded well to treatment during this phase with no adverse occurrences. The patient’s home exercise program included Phase I-IV selective activity with the addition of jogging (Figure 4) for cardiovascular conditioning. At 22 weeks post-operative the patient met all criteria for Phase IV and was cleared to return to gym and recreation sports activity.

OUTCOMES Discharge At the time of discharge the patient diminished his body mass (Body mass-111.13 kg, Body Mass Index33.2.) and scored 76 out of 80 (95%) on his final reassessment with the LEFS which was 10 points higher than the mid-term assessment (i.e., 66 out of 80).

The patient reported only minimal difficulty with sports activity, hopping, and sharp turns while running. The patient’s brace was worn during all sports activity and was considered by the patient when reporting the outcomes from the LEFS. The patient also reported 0/10 pain on the NPRS with activities of daily living, light weight training, and sports activity. The right knee ROM was 5-0-128° and all lower extremity manual muscle tests were graded a 5/5 (Table 1). Muscle length & myofascial mobility was normal except for mildly decreased quadriceps length during prone knee flexion.

Follow-up (1 year) At one year the patient was contacted via phone and reported returning to pain-free physical activity

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 216

Figure 3A, 3B. Patellar maltracking brace.

including weight-training, running, and recreational basketball. The patient continues to wear the brace as a precaution and has experienced no adverse events such as patellar instability since discharge.

Figure 4. Jogging with brace.

DISCUSSION This case report describes the outcomes of a structured rehabilitation program for a young adult male after right knee arthroscopy and open MPFL reconstruction using a tibialis anterior allograft.

The unique nature of this case is the combined arthroscopic procedure with the open MPFL reconstruction with a tibialis anterior allograft, which has only recently been reported in a non-English publication.55 Traditionally, the hamstring and gracillis autograft and allograft have been the tissues of choice by surgeons.55-57 The tibialis anterior allograft has been successful for anterior cruciate ligament (ACL) reconstruction and has shown similar biomechanical qualities to the hamstring and gracillis allografts.58,59 Surgical interventions to address patellofemoral instability are still evolving and have shown mixed outcomes. A recent systematic review by Shah et al29 confirms a high success rate with MPFL reconstruction using either the hamstring or gracillis graft but also notes a surgical complication rate of 26.1%.

Adverse events included patellar fracture, surgical failures, and loss of knee flexion, wound complications, pain, and clinical instability on postoperative exams.29 Thus, patient selection and surgeon familiar-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 217

ity should be considered before having MPFL reconstruction. Also, long-term studies are still needed to further confirm the efficacy of the MPFL reconstruction procedure and the specific graft selection.

Other clinical factors unique to this case report include the patient’s weight loss and use of the custom brace. The patient’s weight loss could have influenced his overall improvements in mobility and function. This is contrary to other reports that have found no correlation between patellar dislocations and being overweight or sedentary in younger individuals.60 However, further studies are needed to confirm these finding especially with taller, larger individuals who actively participate in physical activity. Post-operative bracing is atypical for this procedure in the authors’ practice since most patients are cleared by the referring surgeons to return to function or sports activity without a brace. The potential risk for future dislocations due to the patient’s morphology (e.g. shallow trochlear groove) was considered when ordering the custom knee brace.

Currently, there is no research to confirm this clinical practice. Prior to wearing the brace, the patient was apprehensive about engaging in sports specific movements that involved multidirectional activities due to the related symptoms of instability he previously experienced. This is a common finding among patients with patellar instability who participate in activities that involved multiplaner movements versus uniplanar movements.61 The rehabilitation program presented provides general guidelines, which should be modified in order to meet each patient’s individual needs and functional abilities. The available research on post-operative rehabilitation is inconclusive. Smith et al26 conducted a systematic review investigating early rehabilitation (0-4 weeks) of patients who underwent open or arthroscopic MPFL reconstruction for patellar instability. The authors specifically inquired about the optimal post-operative weight bearing status, the use of knee bracing, and the optimal time to introduce therapeutic exercise. After their review of the literature, they concluded that there was insufficient evidence regarding the optimal post-rehabilitation program and not enough evidence to draw firm conclusions.26 Thus, further controlled trials are needed to develop the optimal rehabilitation program for

individuals who undergo open or arthroscopic MPFL reconstruction.

CONCLUSION Research on post-operative outcomes and the rehabilitation after arthroscopy and open MPFL reconstruction using the tibialis anterior allograft is lacking in the literature. This is the first case report reporting outcomes after this procedure as well as after the fourphase rehabilitation program suggested by the authors.

The program was based on the authors’ clinical experience with this type of injury as well as collaborative input from the surgeon. There is an ongoing need to establish more evidence based rehabilitation programs for open MPFL reconstruction procedures as there is no basis for comparing this patient’s outcomes or progress to alternative intervention plans.

REFERENCES 1. Panni AS, Vasso M, Cerciello S. Acute patellar dislocation. What to do? Knee Surg Sports Traumatol Arthrosc. 2013;21(2):275-8.

2. Waterman BR, Belmont PJ, Jr., Owens BD. Patellar dislocation in the United States: role of sex, age, race, and athletic participation. J Knee Surg.2012;25(1): 51-57.

3. Elias DA, White LM, Fithian DC. Acute lateral patellar dislocation at MR imaging: injury patterns of medial patellar soft-tissue restraints and osteochondral injuries of the inferomedial patella.

Radiology. 2002;225(3):736-743.

4. Sillanpaa PJ, Peltola E, Mattila VM, et al. Femoral avulsion of the medial patellofemoral ligament after primary traumatic patellar dislocation predicts subsequent instability in men: a mean 7-year nonoperative follow-up study. Am J Sports Med. 2009;37(8):1513-1521.

5. Stefancin JJ, Parker RD. First-time traumatic patellar dislocation: a systematic review. Clin Orthop Relat Res. 2007;455:93-101.

6. Fithian DC, Paxton EW, Stone ML, et al. Epidemiology and natural history of acute patellar dislocation. Am J Sports Med. 2004;32(5):1114-1121.

7. Smith TO, Cogan A, Patel S, et al. The intra- and inter-rater reliability of X-ray radiological measurements for patellar instability. The Knee.

2013;20(2):133-138.

8. Smith TO, Clark A, Neda S, et al. The intra- and inter-observer reliability of the physical examination methods used to assess patients with patellofemoral joint instability. The Knee. 2012;19(4):404-410.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 218

9. Smith TO, Davies L, Toms AP, et al. The reliability and validity of radiological assessment for patellar instability. A systematic review and meta-analysis.

Skeletal Radiol. 2011;40(4):399-414.

23. Fithian DC, Powers CM, Khan N. Rehabilitation of the knee after medial patellofemoral ligament reconstruction. Clin Sports Med. 2010;29(2):283-290.

10. White BJ, Sherman OH. Patellofemoral instability.

Bull NYU Hosp Jt Dis. 2009;67(1):22-29.

24. Smith TO DS. The rehabilitation following medial patellofemoral ligament reconstructions. Internet J Orthop Surg. 2008;8(1).

11. Smith TO, Song F, Donell ST, et al. Operative versus non-operative management of patellar dislocation. A meta-analysis. Knee Surg Sports Traumatol Arthrosc.

2011;19(6):988-998.

25. Smith TO WC, McCabe K, and Donell ST. The physiotherapy management of patients following trochleoplasty: rehabilitation protocol and case report. Internet J Orthop Surg. 2007;5(2).

12. Hing CB, Smith TO, Donell S, et al. Surgical versus non-surgical interventions for treating patellar dislocation. Cochrane Database Syst Rev. 2011(11): CD008106.

26. Smith TO RN, Walker J. A systematic review investigating the early rehabilitation of patients following medial patellofemoral ligament reconstruction for patellar instability. Crit Rev Phys Rehab Med. 2007;19(2):79-95.

13. Fithian DC, Khan N. Medial Patellofemoral Ligament Reconstruction. Oper Tech Sports Med. 2010;19(2):79-95.

14. Hautamaa PV, Fithian DC, Kaufman KR, et al. Medial soft tissue restraints in lateral patellar instability and repair. Clin Orthop Relat Res. 1998;34:174-182.

15. Desio SM, Burks RT, Bachus KN. Soft tissue restraints to lateral patellar translation in the human knee. Am J Sports Med. 1998;26(1):59-65.

27. Fisher B, Nyland J, Brand E, et al. Medial patellofemoral ligament reconstruction for recurrent patellar dislocation: a systematic review including rehabilitation and return-to-sports efficacy.

Arthroscopy. 2010;26(10):1384-1394.

16. Andrish J. The management of recurrent patellar dislocation. Orthop Clin North Am. 2008;39(3): 313-327.

28. Nelitz M, Dreyhaupt J, Lippacher S. Combined trochleoplasty and medial patellofemoral ligament reconstruction for recurrent patellar dislocations in severe trochlear dysplasia: a minimum 2-year followup study. Am J Sports Med. 2013;41(5):1005-1012.

17. Felus J, Kowalczyk B. Age-related differences in medial patellofemoral ligament injury patterns in traumatic patellar dislocation: case series of 50 surgically treated children and adolescents. Am J Sports Med. 2012;40(10):2357-2364.

29. Shah JN, Howard JS, Flanigan DC, et al. A systematic review of complications and failures associated with medial patellofemoral ligament reconstruction for recurrent patellar dislocation. Am J of Sports Med. 2012;40(8):1916-1923.

18. Nelitz M, Dreyhaupt J, Reichel H, et al. Anatomic reconstruction of the medial patellofemoral ligament in children and adolescents with open growth plates: surgical technique and clinical outcome. Am J Sports Med. 2013;41(1):58-63.

30. Petri M, von Falck C, Broese M, et al. Influence of rupture patterns of the medial patellofemoral ligament (MPFL) on the outcome after operative treatment of traumatic patellar dislocation. Knee Surg Sports Traumatol Arthrosc. 2013;21(3):683-689.

19. Howells NR, Barnett AJ, Ahearn N, et al. Medial patellofemoral ligament reconstruction: a prospective outcome assessment of a large single centre series. J Bone Joint Surg Br. 2012;94(9): 1202-1208.

31. Hopper GP, Leach WJ, Rooney BP, et al. Does degree of trochlear dysplasia and position of femoral tunnel influence outcome after medial patellofemoral ligament reconstruction? Am J Sports Med. Jan 23 2014. [Epub ahead of print]

20. Deie M, Ochi M, Adachi N, et al. Medial patellofemoral ligament reconstruction fixed with a cylindrical bone plug and a grafted semitendinosus tendon at the original femoral site for recurrent patellar dislocation. Am J Sports Med. 2011;39(1): 140-145.

32. Duchman KR, DeVries NA, McCarthy MA, et al.

Biomechanical evaluation of medial patellofemoral ligament reconstruction. Iowa Orthop J. 2013;33: 64-69.

21. Jain NP, Khan N, Fithian DC. A treatment algorithm for primary patellar dislocations. Sports Health.

2011;3(2):170-174.

22. McConnell J. Rehabilitation and nonoperative treatment of patellar instability. Sports Med Arthrosc.

2007;15(2):95-104.

33. McCulloch PC, Bott A, Ramkumar PN, et al. Strain within the Native and Reconstructed MPFL during Knee Flexion. J Knee Surg.2013. Oct 11. [Epub ahead of print] 34. Higuchi T, Arai Y, Takamiya H, et al. An analysis of the medial patellofemoral ligament length change pattern using open-MRI. Knee Surg Sports Traumatol Arthrosc. 2010;18(11):1470-1475.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 219

35. Hawker GA, Mian S, Kendzerska T, et al. Measures of adult pain: visual analog scale for pain (VAS Pain), numeric rating scale for pain (NRS Pain), mcgill pain questionnaire (MPQ), short-form mcgill pain questionnaire (SF-MPQ), chronic pain grade scale (CPGS), short form-36 bodily pain scale (SF-36 BPS), and measure of intermittent and constant osteoarthritis pain (ICOAP). Arthritis Care Res (Hoboken). 2011;63:Suppl 11:S240-252.

36. Jensen MP, Karoly P, Braver S. The measurement of clinical pain intensity: a comparison of six methods.

Pain. 1986;27:117-126.

37. Yeung TS, Wessel J, Stratford P, et al. Reliability, validity, and responsiveness of the lower extremity functional scale for inpatients of an orthopaedic rehabilitation ward. J Orthop Sports Phys Ther. Jun 2009;39(6):468-477.

38. Watson CJ, Propps M, Ratner J, et al. Reliability and responsiveness of the lower extremity functional scale and the anterior knee pain scale in patients with anterior knee pain. J Orthop and Sports Phys Ther. Mar 2005;35(3):136-146.

39. Binkley JM, Stratford PW, Lott SA, et al. The Lower Extremity Functional Scale (LEFS): scale development, measurement properties, and clinical application. North American Orthopaedic Rehabilitation Research Network. Phys Ther. Apr 1999;79(4):371-383.

40. Norkin C, White D. Measurement of Joint Motion: A Guide to Goniometry. 4th ed. Philadelphia: F. A. Davis; 2009.

41. Hislop HJ, Montgomery J. Daniels and Worthingham’s Muscle Testing: Techniques of Manual Examination. 7th ed. Philadelphia, Pa: WB Saunders Co; 2002.

42. Hubbard DR, Berkoff GM. Myofascial trigger points show spontaneous needle emg activity. Spine.

1993;18:1803-1807.

43. American Physical Therapy Association. Guide to Physical Therapist Practice. 2nd ed. Alexandria: American physical Therapy Association; 2003.

44. Wainner RS, Whitman JM, Cleland JA, et al. Regional interdependence: a musculoskeletal examination model whose time has come. J Orthop Sports Phys Ther. Nov 2007;37(11):658-660.

45. Amis AA. Current concepts on anatomy and biomechanics of patellar stability. Sports Med Arthrosc.Jun 2007;15(2):48-56.

46. Stevens-Lapsley JE, Balter JE, Wolfe P, et al.

Relationship between intensity of quadriceps muscle neuromuscular electrical stimulation and strength recovery after total knee arthroplasty. Phys Ther. Sep 2012;92(9):1187-1196.

47. Dirks ML, Wall BT, Snijders T, et al. Neuromuscular electrical stimulation prevents muscle disuse atrophy during leg immobilization in humans. Acta Physiol (Oxf). Nov 20 2013.

48. Atamaz FC, Durmaz B, Baydar M, et al. Comparison of the efficacy of transcutaneous electrical nerve stimulation, interferential currents, and shortwave diathermy in knee osteoarthritis: a double-blind, randomized, controlled, multicenter study. Arch Phys Med Rehab. May 2012;93(5):748-756.

49. Gundog M, Atamaz F, Kanyilmaz S, et al.

Interferential current therapy in patients with knee osteoarthritis: comparison of the effectiveness of different amplitude-modulated frequencies. Am J Phys Med Rehab. Feb 2012;91(2):107-113.

50. Fukuda TY, Rossetto FM, Magalhaes E, et al. Shortterm effects of hip abductors and lateral rotators strengthening in females with patellofemoral pain syndrome: a randomized controlled clinical trial.

J Orthop Sports Phys Ther. Nov 2010;40(11):736-742.

51. Peters JS, Tyson NL. Proximal exercises are effective in treating patellofemoral pain syndrome: a systematic review. Int J Sports Phys Ther. Oct 2013;8(5):689-700.

52. Mills K, Blanch P, Dev P, et al. A randomised control trial of short term efficacy of in-shoe foot orthoses compared with a wait and see policy for anterior knee pain and the role of foot mobility. British J of Sports Med. Mar 2012;46(4):247-252.

53. Barton CJ, Munteanu SE, Menz HB, et al. The efficacy of foot orthoses in the treatment of individuals with patellofemoral pain syndrome: a systematic review. Sports Med. May 1 2010;40(5):377395.

54. Herman K, Barton C, Malliaras P, et al. The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review. BMC Medicine. 2012;10:75.

55. Zhang H, Hong L, Geng X, et al. Reconstruction of medial patellofemoral ligament for recurrent patellar dislocation. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. Aug 2011;25(8):925-930.

56. Schottle P, Schmeling A, Romero J, et al. Anatomical reconstruction of the medial patellofemoral ligament using a free gracilis autograft. Arch Orthop Trauma Surg. Mar 2009;129(3):305-309.

57. Singhal R, Rogers S, Charalambous CP. Doublebundle medial patellofemoral ligament reconstruction with hamstring tendon autograft and mediolateral patellar tunnel fixation: a meta-analysis of outcomes and complications. Bone Joint J. Jul 2013;95-b(7):900-905.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 220

58. Haut Donahue TL, Howell SM, Hull ML, et al. A biomechanical evaluation of anterior and posterior tibialis tendons as suitable single-loop anterior cruciate ligament grafts. Arthroscopy. Jul-Aug 2002;18(6):589-597.

59. Pearsall AWt, Hollis JM, Russell GV, Jr., et al. A biomechanical comparison of three lower extremity tendons for ligamentous reconstruction about the knee. Arthroscopy. Dec 2003;19(10):1091-1096.

60. Atkin DM, Fithian DC, Marangi KS, et al.

Characteristics of patients with primary acute lateral patellar dislocation and their recovery within the ďŹ rst 6 months of injury. Am J of Sports Med. Jul-Aug 2000;28(4):472-479.

61. Smith TO, Donell ST, Chester R, et al. What activities do patients with patellar instability perceive makes their patella unstable? The Knee. Oct 2011;18(5):333339.

63.

64.

65.

66.

torque and functional performance. J Ath Train. Oct 1996;31(4):335-340.

Hubscher M, Zech A, Pfeifer K, et al. Neuromuscular training for sports injury prevention: a systematic review. Med Sci Sports Exerc. Mar 2010;42(3):413-421.

Stanek JM, Meyer J, Lynall R. Single-limb-balance difďŹ culty on 4 commonly used rehabilitation devices. J of Sport Rehab. Nov 2013;22(4):288-295.

Kidgell DJ, Horvath DM, Jackson BM, et al. Effect of six weeks of dura disc and mini-trampoline balance training on postural sway in athletes with functional ankle instability. J of Strength Cond Res. May 2007;21(2):466-469.

Egana M, Donne B. Physiological changes following a 12 week gym based stair-climbing, elliptical trainer and treadmill running program in females. J Sports Med and Phys Fitness. Jun 2004;44(2):141-146.

62. Wawrzyniak JR, Tracy JE, Catizone PV, et al. Effect of closed chain exercise on quadriceps femoris peak

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 221

IJSPT

CASE REPORT

TREATMENT OF DISTAL ILIOTIBIAL BAND SYNDROME IN A LONG DISTANCE RUNNER WITH GAIT REď&#x161;şTRAINING EMPHASIZING STEP RATE MANIPULATION Darrell J. Allen, PT, DPT, SCS, MS, CSCS1

ABSTRACT Background & Purpose: Iliotibial band syndrome (ITBS) is a common injury associated with long distance running. Researchers have previously described biomechanical factors associated with ITBS. The purpose of this case report is to present the treatment outcomes in a runner with distal ITBS utilizing running gait re-training to increase step rate above the runnerâ&#x20AC;&#x2122;s preferred or self-chosen step rate.

Case Description: The subject was a 36 year old female runner with a diagnosis of left knee ITBS, whose pain prevented her from running greater than three miles for three months. Treadmill video analysis of running form was utilized to determine that the subject had an excessive stride length, strong heel strike, decreased knee flexion angle at initial foot contact, and excessive vertical displacement. Cadence was 168 steps/minute at a preferred running pace of 6.5 mph. Treatment emphasized gait re-training to increase cadence above preferred. Treatment also included iliotibial band flexibility and multi-plane eccentric lower extremity strengthening.

Outcomes: The subject reported running pain free within 6 weeks of the intervention with a maximum running distance of 7 miles and 10-15 miles/week progressing to half marathon distance and 20-25 miles/ week at 4 month follow up. Step rate increased 5% to 176 steps/minute and was maintained at both the 6 week and 4 month follow up. 5K run pace improved from 8:45 to 8:20 minutes/Km. LEFS score improved from 71/80 to 80/80 at 4 month follow up.

Discussion: This case demonstrated that a 5% increased step rate above preferred along with a home exercise program for hip strengthening and iliotibial band stretching, improved running mechanics and reduced knee pain in a distance runner.

Key Words: Gait retraining, iliotibial band band syndrome, running Level of Evidence: 4-single case report

1

Cleveland Clinic Rehabilitation and Sports Therapy, Cleveland, Ohio, USA

CORRESPONDING AUTHOR Darrell J. Allen, PT, DPT, SCS, MS, CSCS 8701 Darrow Rd Twinsburg, OH 44087 E-mail: allend4@ccf.org

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 222

INTRODUCTION/BACKGROUND Iliotibial band syndrome (ITBS) is the second most common cause of knee pain in runners and the most common cause of lateral knee pain.1 ITBS is an overuse injury that has traditionally been described as being caused by friction or rubbing of the distal portion of the iliotibial band (ITB) over the lateral femoral condyle with repeated flexion and extension of the knee.2 It has been noted that this friction is greatest at 20-30 degrees of knee flexion which occurs during the early portion of the stance phase of running.3 This theory has been challenged; however, and recent studies have focused on the frontal and transverse plane mechanics of the knee and lower extremity that may contribute to the development of this injury.4,5 The attachments and function of the ITB in gait seem to support the frontal and transverse plane focus. The ITB originates at the fascial components of the gluteus maximus, gluteus medius, and tensor fascia latae muscles and has distal attachments at the lateral border of the patella, lateral patellar retinaculum, and Gerdyâ&#x20AC;&#x2122;s tubercle.5 The ITB functions to provide stability of the lateral hip and resists knee adduction and internal rotation during the stance phase of the gait cycle.

Noehren et al5 compared a group of female distance runners with ITBS to healthy matched controls through instrumented gait analysis. They found that the ITBS group exhibited significantly greater hip adduction and knee internal rotation than the control group. They hypothesized that these combined motions created excessive strain to the ITB as it attempted to decelerate hip adduction and knee internal rotation causing compression of its distal aspect against the lateral femoral condyle.5 Ferber et al6 found a similar conclusion as they compared a group of female recreational runners with healthy controls and found that the ITBS group had higher peak hip adduction and knee internal rotation angles than the controls.6 These results suggest that atypical hip and knee mechanics are the primary factors in the development of ITBS. Finally, Hamill et al4 reported that runners with ITBS had a greater strain rate of the ITB during midsupport of running gait which may be indicative of rapid, excessive, or decreased control of adduction and internal rotation of the knee and lower extremity.4

While the results of research have been able to provide some very significant information to clinicians regarding potential biomechanical causes or reasons for ITBS in runners, literature on treatment interventions specific to runners has been lacking.7,8 Fredericson et al2 described a multiple phase approach to treatment of ITBS in runners. Their treatment approach utilized three phases. The acute phase focused on activity modification and reduction of inflammation, the subacute phase emphasized flexibility exercises, massage, basic hip abductor and external rotator strengthening, and the recovery and strengthening phase progressed to multi-planar functional hip abductor strengthening exercises. After these three phases of treatment they then progress to a return to running phase, but that phase is nonspecific in regards to recommending changes to running mechanics with the exception of a brief mention for a recommendation toward faster paced running that they suggest would increase knee flexion at foot contact and help avoid the zone of impingement of the ITB.2 Baker et al9 then updated this multi-phase ITBS treatment approach with a greater emphasis on correcting faulty hip and knee mechanics through stretching and strengthening exercises, but again did not specifically address running mechanics or running gait re-training in their program.9 There has been, however, an abundance of recent research on running mechanics and gait re-training although not specific to ITBS. One of the most significant areas of research in this area has been regarding step rate manipulation and its effects on running mechanics. Heiderscheidt et al10 assessed the effects of cadence manipulation on both running mechanics and impact forces by increasing step rate above a runnerâ&#x20AC;&#x2122;s preferred by 5% and 10%. They found that key components of running mechanics were improved including decreased heel strike, decreased braking impulse, decreased step length, and decreased vertical excursion. There was also a significant reduction in impact forces when comparing a runnerâ&#x20AC;&#x2122;s preferred step rate to step rates 5% or 10% slower than preferred. They also found that there was a substantial reduction in mechanical work performed at the knee with as little as 5% increase in step rate.10 Hobara et al11 performed a similar analysis and their results also showed decreased impact forces when

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 223

step rate was increased above preferred.11 Chumanov et al12 further found that the gluteus medius and maximus demonstrated increased firing during late swing phase in anticipation of loading that was greater as the step rate was increased above preferred. They hypothesized that this increased hip muscle activity may be beneficial for runners with knee pain.12 Current researchers have suggested that landing closer to the center of mass, utilizing a slight forward lean, and more knee flexion at initial contact leads to reduced loading forces.10,11

assessment of running mechanics and a therapeutic exercise program. Prior to coming to physical therapy the subject had not received any formal treatments. Independently, the subject rested from running, performed light stretching, and continued to participate in gym based strength training, which was not painful. The subject noted a past history of right ITBS that resolved with rest and stretching.

The subject’s goal was to return to running pain free with the intent to train and complete a half or full marathon.

The purpose of this case report is to present the outcome of an intervention for ITBS that emphasized gait re-training with step rate manipulation in addition to traditional treatment methods such as flexibility and hip abductor strengthening exercises. This case demonstrates how step rate manipulation led to the occurrence of the desired factors of running mechanics mentioned above that have been associated with decreased impact forces. The author’s hypothesize that the observed improved running mechanics influenced loading forces and led to an outcome of pain free running.

Based on the information gathered from the physician’s report and in the subject’s history, this subject was deemed appropriate for physical therapy evaluation with an emphasis on assessing running mechanics and form. The plan for evaluation was to assess lower extremity alignment in weight bearing and non-weight bearing, functional biomechanics, walking gait, flexibility/range of motion, strength, and to perform video analysis of running form. Video running analysis was planned, to include assessment of running form from the rear, side, and front views. As part of the running analysis cadence (steps/minute) would be counted and calculated by the therapist.

Special tests of the knee joint, palpation, and observation of the knee also would be performed to help rule out potential differential diagnosis. This subject was deemed an excellent candidate for this type of evaluation and the possible intervention of step rate manipulation due to the presence of pain only with running, a history suggestive of an overuse injury with a biomechanical component, and negative radiographs.

SUBJECT HISTORY/REVIEW OF SYSTEMS The subject was a 36 year-old professional female who had been a recreational runner for approximately three years and participated in road races including 5K, 10K, and half marathons. Without symptoms, the subject ran 15-20 miles per week on paved roads or trails wearing neutral running shoes.

The subject’s chief complaint was left lateral knee pain that occurred with running. Onset of a dull aching pain at the left lateral knee would typically occur prior to the three-mile distance resulting in a stop of the run. This pain had been present for three months initially presenting itself as a sharp pain that made the left knee feel like it was locking up near the end of a half marathon relay run. The subject also noted right great toe pain that had been present since it was bumped when slipping on stairs on a date after the initial onset of her knee pain.

The subject was initially seen by a non-surgical orthopedist and was given a diagnosis of left ITBS. At the time of this visit, knee radiographs were obtained and showed no abnormalities. The physician referred the patient to physical therapy for

EXAMINATION Prior to the physical examination the subject completed a visual analog scale (VAS) where 0 is no pain and 10 is the most pain possible, to assess the current level of pain. The subject’s baseline pain at rest was 0/10, but with running up to three miles was rated at 4/10. The subject also completed the Lower Extremity Functional Scale (LEFS) to evaluate functional status with regards to knee symptoms. This self-assessment functional tool has been shown to be both valid and reliable.13 The subject’s score on the lower extremity functional scale was 71/80, with 80 representing maximum function. Scores were reduced on each of the running specific items within

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 224

the LEFS, representing the deficit from maximum function.

Physical evaluation of the subject revealed palpation tenderness at the left distal ITB of the lateral left knee. Knee joint effusion was not present and knee range of motion was full and pain free. McMurray’s test was negative for meniscal pathology and varus and valgus stress tests showed excellent stability and were symptom free. Ober’s test was positive bilaterally, hamstring flexibility of 75/90 bilaterally and mild piriformis tightness on the involved side with a figure four test were also observed. Manual muscle testing of the hip abductors was 4/5 on the left and 4+/5 on the right. All other LE manual muscle tests were 5/5.

Weight bearing alignment at rest showed that the patient had average medial arch height, vertical calcaneus and slightly varus knees. Non-weightbearing assessment of alignment found a mild rearfoot varus, mild ankle equinus, and a flexible first ray and mid-foot. Walking gait analysis was performed in the clinic gym utilizing both real time observation as well as slow motion video analysis. Walking gait analysis was significant for contralateral pelvic drop (bilateral), a supinatory biased gait, and a medial heel whip most likely consistent with tight calves.

Functional strength and movement testing found that single leg balance was good (30 second single leg stance completed), but the subject had a mild tendency to lose balance in a pronatory direction. The Star Excursion Balance Test was completed using the Functional Testing Grid (Total Gym, San Diego, CA).

Reaches were performed in the anterior, medial, and posterior-medial rotational directions. The focus of this testing was on the quality of motion rather than maximum distance. This testing provided very meaningful information as the subject showed excessive dynamic knee valgus (knee adduction, mid-foot pronation, and contralateral pelvic drop with lateral trunk lean) of the left leg greater than the right most notable with medial reaches (frontal plane). The subject attempted to compensate for a deficiency in controlling dynamic knee valgus by keeping the knee in a varus or abducted position. When the testing challenged the compensatory comfort zone, the lack of control of dynamic knee valgus was noted.

This was suggestive of hip abductor and external rotator weakness.

Video running analysis was completed with the subject running on a treadmill. A brief warm up consisting of dynamic stretching (sagittal and frontal plane leg swings, 1 rep, 30 seconds each) and 5 minutes walking on the treadmill at 3.5 mph to acclimate to the treadmill were performed. The subject initiated running at a self-selected pace of 6.5 mph. The subject continued to run for several minutes and verbalized when a comfortable pace with typical form was reached.

Digital video was then taken from the rear, side, and front views by the evaluating physical therapist (Sony DCR SX65) video camera (60 fps). Cadence was then assessed by counting each time the right foot hit the ground for 30 seconds and this number was then multiplied to calculate the total steps per minute at 168.

Video was then viewed with the subject at both regular and slow motion speeds. The video was viewed on a 20 inch Vizio wall mounted flat screen monitor via a direct video camera connection (Figure 1).

Computerized video analysis was not performed to assess objective measures of running mechanics, but the following significant observations were made through repeated visual observation of the video in slow motion by utilizing the camera’s slow motion viewing function. At initial contact the subject had a heel strike pattern. Initial foot contact was significantly in front of her center of mass. Her knee was

Figure 1. Initial foot contact position before gait re-training. A.) Heel strike initial foot contact in front of the subject’s center of mass. B.) Upright trunk posture C.) Lead knee extended at approximately 10 degrees at initial foot contact. D.) Center of mass line.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 225

near full extension (approximately 10 degrees knee flexion) and her trunk was upright and lacking a forward leaning posture. During mid-stance the subject had a contralateral pelvic drop, which was seen bilaterally and appeared equal in degree of motion.

Through her gait cycle it was observed that she had significant and excessive vertical center of mass displacement. Finally, the subject had adequate knee separation and did not show crossing over beyond midline with her stride on either side.

It was determined that the subject’s initial cadence may have been contributory to several variables (heel strike, initial contact out in front of her center of mass, and excessive vertical displacement). Each of these variables are known to be associated with increased impact forces on the LE and increased impact forces have been connected to running related injuries.14,15,16,17 Multiple authors have described the relationship between vertical displacement of the center of mass, vertical impact forces, and step frequency.10,11,18,19,20 These relationships have been explained through the spring-mass model. Farley et al18 showed that as step frequency increased at a given speed that vertical displacement of the center of mass and vertical impact forces decreased.18 Slower step frequencies at a given speed had the opposite effect.

The initial evaluation also revealed contralateral pelvic drop during running, which is linked to functional hip abductor weakness. Dynamic knee valgus during functional movement testing was also noted, confirming this diagnosis. This led to the primary intervention of running gait re-training with emphasis on step rate manipulation. The hypothesis was that if step rate was increased above her preferred rate by at least 5% that each of the variables above could be improved, impact forces could be decreased, and the stress on the iliotibial band could be reduced. This would hopefully allow the achievement of the primary physical therapy goal of pain free running. The plan was to also address the functional hip weakness with strengthening exercises and the ITB tightness with flexibility exercises as is typical with rehabilitation of this diagnosis.

INTERVENTION The primary intervention was running gait re-training with step rate manipulation. It was determined

during the video gait examination that the subject’s running cadence was 168 steps per minute at a preferred running pace of 6.5 mph. Based on the research by Heiderscheidt et al.10 it was determined that a goal would be to increase the subject’s step rate by 5% or 8 steps per minute to 176 steps per minute. Heiderscheidt et al10 showed that even a 5% increase in step rate above one’s preferred rate could effectively reduce impact forces transmitted through the knees and improve running mechanics such as foot strike pattern, stride length, and vertical displacement. At the time of the subject’s first physical therapy visit the running gait re-training was initiated. The subject was allowed to warm up and accommodate to the treadmill as stated in the examination. The subject then proceeded to run at a preferred pace of 6.5 mph. A metronome set to 176 beats per minute was then utilized to provide auditory feedback to increase step rate to match the beat of the metronome while still running at the 6.5 mph pace. The subject was also provided with simple verbal cues that included “run quietly” and “let your feet strike under your body as you fall forward”. The subject was able to successfully achieve this cadence during the initial instruction. Instructions were given for practicing this running form at home with a goal of achieving 176 steps per minute with help of the metronome. The subject was asked to run 1-2 miles, three times per week with at least one rest day between running days so long as running was pain free. She was instructed to utilize constant auditory cueing from the metronome until she was able to easily and consistently match the cadence goal. At that point the auditory cueing from the metronome could be used intermittently to check compliance and then could be removed completely once consistent compliance was confirmed. Noehren et al21 found that it took approximately eight training sessions to assume new running mechanics from visual feedback with initial feedback being used constantly and then gradually taken away in later sessions. This case utilized a similar model with auditory cueing.21 The first visit also consisted of instruction on a home exercise program that included a wall ITB stretch (Figure 2) to be performed 3 times daily for 3 sets of 20 seconds on each leg. The subject was instructed to perform theraband resisted (at ankles)

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 226

Figure 2. Wall iliotibial band stretch.

Figure 4. Eccentric step-down (posterior-medial direction shown).

Figure 3. Band resisted side-stepping and forward-backward walking.

Figure 5. Star excursion balance and reach (anterior-medial direction shown).

side-stepping and forward and backward walking (Figure 3) for dynamic hip abductor strength. Single leg eccentric control exercises that included the star excursion balance and reach in the anterior-medial

rotation, medial, and posterior-medial rotation directions (Figure 4) were issued. These same motions were also to be performed off of a 6-inch step with a toe touch in each plane of motion (Figure 5). These

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 227

single leg eccentrics were to be performed for 1-2 sets of 10 repetitions three times per week with at least one rest day between each session. Handouts were issued with instructions. Ice massage for five minutes to the lateral knee was recommended as needed if pain should occur.

Follow up visits were conducted at four weeks and six weeks following the initial evaluation. These visits consisted of re-assessment of running form, including a second video taken at four weeks. Step rate was verified and reinforced with a metronome at each visit. Home exercises were reviewed to assess progress and to verify correct performance. During these visits the subject was also given guidance for the progression of the home running program which consisted of a 10% increase in total mileage per week so long as running was pain free. Home strengthening and flexibility exercises were continued as initially instructed throughout this time period. Formal discharge from physical therapy occurred after the six week follow up visit. The subject was brought back, however, at four months following initial evaluation to assess whether changes in running form and step rate had been maintained. Video was also taken at the four-month post evaluation visit to verify longterm compliance with these changes.

OUTCOMES At four weeks after the initial evaluation the subject reported compliance with all recommendations and had been successful running up to 3.5 miles without knee pain. At that time running mechanics were reassessed with video. Cadence was assessed at 176 steps per minute without the use of a metronome.

Foot strike was a mid-foot strike pattern. Initial foot contact was now directly beneath her shoulder (foot strike almost directly under her center of mass) with her trunk leaning forward slightly rather than the upright posture at initial evaluation (Figure 6). Vertical displacement was visually observed to be minimal and much less than at the time of initial evaluation.

These improved running mechanics that were visualized presented an assumption of decreased impact forces present with running. Pelvic drop was now absent as compared to the contralateral pelvic drop seen at the first visit. Hip abduction strength was improved to 4+/5 on the left. More importantly, the subject demonstrated improved ability to control

Figure 6. Initial foot contact position after gait re-training.

A.) Midfoot strike pattern closer to the subjectâ&#x20AC;&#x2122;s center of mass.

B.) Mild forward trunk lean posture. C.) Lead knee extended at approximately 20 degrees at initial foot contact. D.) Center of mass line.

dynamic valgus of the left LE with the Star Excursion Balance Test although there were still mild deficits (excessive knee adduction-frontal plane motion).

At six weeks follow up the subject reported feeling great and had no knee pain with running now up to seven miles. Comfort was reported with the new running form with an improved feeling of strength.

Running form was assessed again visually on the treadmill at 6.5 mph. Cadence was verified at 176 steps per minute and form was near ideal and consistent with changes seen on video at the four week follow up (Figure 7). Strength was also improved with hip abduction manual muscle test 5/5 bilaterally.

Star Balance Excursion Test showed excellent control of knee motion and lower extremity loading with reaches in the anterior, medial, and posterior-medial rotation directions to test all three planes of motion.

At the four month follow up the subject reported a successful progression of running distance to 13.1 miles without knee pain (Figure 8). Weekly training mileage had been advanced to 25 miles per week.

Cadence had remained consistent at 176 steps per minute. Hip abduction strength remained 5/5 bilat-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 228

Figure 7. Cadence (steps/minute) at initial evaluation and 6 week follow up visit.

Figure 10. 5 Kilometer run pace pre-injury and at the 4 month follow up visit.

her 5 kilometer running pace had improved from a 8:45 per mile pace to a 8:20 per mile pace, but it is unclear whether this was at all related to the increased step-rate and improved running mechanics or was related to training (Figure 10).

Figure 8. Pain-free maximum running distance (miles) at initial evaluation and the 4 month follow up visit.

Figure 9. Lower Extremity Functional Scale (LEFS) score at initial evaluation and 4 month follow up visit.

erally. Star Balance Excursion Test showed excellent control of knee motion in the frontal plane and excellent control of loading in all planes. LEFS score was improved to 80/80 as compared to 71/80 at initial evaluation with running related items now showing no deficits (Figure 9). The subject also noted that

DISCUSSION This case report presents running gait re-training as a primary treatment intervention for the rehabilitation of a runner with distal ITBS. This subject was able to successfully return to pain free running and to maintain that success up to a four month follow up period. Central to this success was a transformation of running form through gait re-training emphasizing increasing step rate 5% above the subjectâ&#x20AC;&#x2122;s preferred rate. This simple increase in step rate, achieved initially with help from a metronome, was able to improve running mechanics and components of faulty running form that may contribute to ITBS. The metronome was only used during her first month of rehabilitation as she was able to successfully progress from constant auditory cueing, to intermittent, to no auditory cueing at all while maintaining her new cadence. As running form improved with the achievement of an increased cadence, the subject was able to run greater distances and progress overall mileage without pain.

Heiderscheidt et al10 showed that just a 5% increase in step rate above preferred significantly reduced total work at the knee, reducing the total amount of joint loading. This increased step rate also shortened stride, decreased the amount of heel strike, reduced vertical displacement, and reduced the peak hip adduction and internal rotation angles.10 These char-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 229

acteristics are all factors that could contribute to ITBS as researchers have recently shown that the peak hip adduction angle and knee internal rotation angles are characteristic of runners with ITBS.4,5 Impact forces also may magnify hip adduction and knee internal rotation angles as the body works to decelerate loading forces. Running also may produce fatigue with repetition and as one fatigues these faulty mechanics may worsen.22,23 Improving running form via a step rate increase of 5% addressed and improved running mechanics. These improvements likely led to a reduction of impact forces and faults that may be central to the cause of this injury.

It should be noted that the subject of this case did also improve hip abductor strength, which has been described in the literature as being an important component of the treatment of ITBS.2,9,24 Theoretically, improving hip abductor strength could help to decrease the peak hip adduction and knee internal rotation angles through improved ability to decelerate these motions. The literature, however, has not shown an abundance of evidence that traditional treatment focusing on hip abductor strengthening and movement training exercises alone is successful in altering running mechanics. In fact, Willy et al25 showed that a hip abductor strengthening program had no significant effect on running mechanics.25 Ferber et al.26 compared runners with ITBS and healthy controls. They expected the increased hip adduction position associated with ITBS to result in increased demands on the hip abductor muscles.

They found, however, that the hip abductor moment was the same between groups and suggested that the timing of muscle activation may be more important than the magnitude of muscle activation.26 Chumanov et al12 measured muscle activity of the lower extremity in runners at their preferred step rate, +5%, and +10%. They found that there was an increase in muscle activity, especially of the gluteus maximus and gluteus medius, in anticipation of foot-ground contact.12 This pre-activation of muscle activity at higher step-rates is thought to enhance muscle activity during the loading response and to regulate leg stiffness. This is also consistent with research by Farley et al18 who described an increase in leg stiffness at higher step rates at a given speed.18 It is likely that improved strength played a role in

the rehabilitation of this patient, but improved muscle activation timing through an increased step rate was also probably related to her success.

CONCLUSION Gait re-training with step rate manipulation may be an important and practical intervention for the treatment of distal ITBS in runners. This case report provides evidence that when combined with traditional strengthening of the hip abductors and ITB flexibility exercises, increasing step rate above preferred rate could improve running mechanics and contribute to the successful return of a runner to pain free distance running. Future research may be helpful to isolate the effects of step rate manipulation versus other interventions such as hip abductor strengthening or other gait re-training methods in order to further define the relative importance of cadence manipulation in the rehabilitation of runners with ITBS. REFERENCES 1. Taunton JE, Ryan MB, Clement DB, McKenzie DC, Lloyd-Smith DR, Zumbo BD. A retrospective casecontrol analysis of 2002 running injuries. Br J Sports Med. 2002;36:95-101.

2. Fredericson M, Weir A. Practical management of iliotibial band friction syndrome in runners. Clin J Sport Med. 2006;16:261-268.

3. Orchard JW, Fricker PA, Abud AT, Mason BR. Biomechanics of iliotibial band syndrome in runners. Am J Sports Med. 1996;24(3):375-379.

4. Hamill J, Miller R, Noehren B, Davis I. A prospective study of iliotibial band strain in runners. Clin Biomech. 2008;23:1018-1025.

5. Noehren B, Davis I, Hamill J. Prospective study of the biomechanical factors associated with iliotibial band syndrome. Clin Biomech.2007;22:951-956.

6. Ferber R, Davis I, Williams D. Gender differences in lower extremity mechanics during running. Clin Biomech. 2003;18:350-357.

7. Ellis R, Hing W, Reid D. Iliotibial band friction syndrome- a systematic review. Manual Therapy.2007;12:200-208.

8. van der Worp MP, van der Horst N, de Wijer A, Backx FJ, Nijhuis-van der Sanden MW. Iliotibial band syndrome in runners: A systematic review. Sports Med. 2012;42(11):969-992.

9. Baker RL, Souza RB, Fredericson M. Iliotibial band syndrome: soft tissue and biomechanical factors in evaluation and treatment. PM&R. 2011;3:550-561.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 230

10. Heiderscheit B, Chumanov E, Michalski M, Wille C, Ryan M. Effects of step rate manipulation on joint mechanics during running. Med Sci Sports Exerc.2011;42(2):296-302.

11. Hobara H, Sato T, Sakaguchi M, Sato T, Nakazawa K. Step frequency and lower extremity loading during running. Int J Sports Med. 2012;33:310-313.

12. Chumanov ES, Wille CM, Michalski MP, Heiderscheit BC. Changes in muscle activation patterns when step rate is increased. Gait Posture. 2012;36:231-235.

13. Binkley JM, Stratford PW, Lott SA, Riddle DL. The lower extremity functional scale (LEFS): scale development, measurement properties, and clinical application. North American Orthopaedic Rehabilitation Research Network. Phys Ther.

1999;79(4):371-83.

14. Milner CE, Ferber R, Pollard, C, Hamill J, Davis I. Biomechanical factors associated with tibial stress fractures in female runners. Med Sci Sports Exer.

2006;38(2):323-328.

15. Cheung R, Davis I. Landing pattern modiďŹ cation to improve patellofemoral pain in runners: a case series. J Orthop Sports Phys Ther. 2011;24(12)914:919.

16. Diebal AR, Gregory R, Alitz C, Gerber P. Forefoot running improves pain and disability associated with chronic exertional compartment syndrome. Am J Sports Med.2012;40(5):1060-1067.

17. Pohl MB, Hamill J, Davis I. Biomechanical and anatomic factors associated with a history of plantar fascitis in female runners. Clin J Sport Med.2009;19:372-376.

18. Farley CT, Gonzalez O. Leg stiffness and stride frequency in human running. J Biomech.

1996;29(2):181-6.

19. Rabita G, Slawinski J, Girard O, Bignet F, Hausswirth C. Spring-mass behavior during exhaustive run at constant velocity in elite triathletes. Med Sci Sports Exerc.2011;43(4):685-692.

20. Morin JB, Samozino P, Zameziati K, Belli A. Effects of altered stride frequency and contact time on leg-spring behavior in human running.

J Biomech.2007;40:3341-3348.

21. Noehren B, Scholz J, Davis I. The effect of real-time gait training on hip kinematics, pain, and function in subjects with pattellofemoral pain syndrome. Br J Sports Med.2011;45:691-696.

22. Miller RH, Meardon SA, Derrick TR, Gillette JC. Continuous relative phase variability during an exhaustive run in runners with a history of iliotibial band syndrome. J Appl Biomech. 2008;24(3):262-270.

23. Miller RH, Lowry JL, Meardon SA, Gillette JC. Lower extremity mechanics of iliotibial band syndrome during an exhaustive run. Gait Posture.

2007;26(3):407-413.

24. Fredericson M, Wolf C. Iliotibial band syndrome in runners: innovations in treatment. Sports Med. 2005;35(5):451-459.

25. Willy R, Davis I. The effect of a hip strengthening program on mechanics during running and during a single leg squat. J Orthop Sports Phys Ther.

2011;41(9):625-632.

26. Ferber R, Noehren B, Hamill J, Davis I. Competitive female runners with a history of iliotibial band syndrome demonstrate atypical hip and knee kinematics. J Orthop Sports Phys Ther.2010;40(2):52-58.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 231

IJSPT

CASE REPORT

REHABILITATION STRATEGIES ADDRESSING NEUROCOGNITIVE AND BALANCE DEFICITS FOLLOWING A CONCUSSION IN A FEMALE SNOWBOARD ATHLETE: A CASE REPORT John Faltus, DPT, MS, SCS, LAT, ATC, CSCS1

ABSTRACT Head injuries, including concussions, in athletes can account for an extended period of time lost from sports competition. Neurocognitive and balance deficits which may linger following a concussion affect an athleteâ&#x20AC;&#x2122;s ability to return to sport safely. If these deficits are not specifically addressed in a rehabilitation program then the athlete may be at risk for not only additional concussions but possible musculoskeletal injury. ImPACT testing is a reliable method for identifying neurocognitive deficits and assists in the development of a neurocognitive training program. The information gathered from ImPACT may also indicate risk for musculoskeletal injuries. Research evidence suggesting specific rehabilitation strategies and interventions addressing neurocognitive deficits following a concussion is lacking. Progressions in a neurocognitive training program may include the integration of balance, reaction training, and activities that address memory deficits. The purpose of this case report is to discuss the evaluation and treatment plan for a female snowboard athlete following a concussion.

Key words: Concussion, neurocognitive rehabilitation, reaction training Level of Evidence: 5

1

Howard Head Sports Medicine, Avon, Colorado, USA

Acknowledgments: The author acknowledges the contributions of Kevin Heinz from Vail Valley Medical Center for his assistance in obtaining photographs of exercises demonstrated in this case report.

CORRESPONDING AUTHOR John Faltus, DPT, MS, SCS, ATC, CSCS Physical Therapist/Athletic Trainer Howard Head Sports Medicine The Westin Riverfront Resort and Spa 126 Riverfront Lane Avon, Colorado 81620 Phone: 970-845-9600 Email: john.faltus@vvmc.com

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 232

BACKGROUND AND PURPOSE Emergency department data in the United States indicates that roughly 173,285 sports and recreational related traumatic brain injuries (TBI) occur per year, including concussions.1 Additionally, national injury surveillance data has indicated that TBI accounts for 9% of all injuries in high school sports.2 A concussion is typically defined as a temporary loss of brain function which may be accompanied by physical, cognitive or emotional symptoms and may be categorized as a traumatic head injury depending upon severity.

Concussion rates in high school athletes have been found to be highest in the athletes who participate in boys lacrosse, boys hockey, football, girls lacrosse, and girls soccer.3,4 While there is an obvious correlation between the contact nature of sports like hockey, football and lacrosse with concussion rate, sports that require change of direction, acceleration, high-risk maneuvers and participation on varied surfaces with the potential for changing climate conditions must also be considered. A sport such as snowboarding fits this category and also involves a high-risk for musculoskeletal injuries as well. While there is extensive research evidence which discuss the rate of musculoskeletal injuries in snowboarding, with injuries to the wrist, hand, shoulder and ankle having the highest occurrence,5,6,7,8 literature investigating the concussion rate in this sport is lacking. Data from injury surveillance records indicates that while head injuries do occur in snowboarding, these injuries are categorized in most studies as injuries to the head and face, which may include both lacerations and traumatic brain injuries, with no mention of concussion occurrence in either case.9,10,11,12 In a ten-year retrospective review of ski and snowboard-related injuries, head injuries accounted for 52% of total injuries with roughly 24% of these injuries occurring in the snowboard population.11 The majority of these head injuries were then identified as traumatic brain injuries which occurs when an external force traumatically injures the brain and can be potentially fatal.11 Given the increased focused on concussion and head injury occurrence in contact sports such as football, hockey and lacrosse as previously discussed,3,4 it would be important to further investigate the prevalence and risk of concussion in sports such as snowboarding, freestyle skiing, skateboarding, or extreme freestyle motorbiking which combine high velocity with the

performance of aerial stunts or tricks. This becomes especially relevant as experienced athletes in these sports attempt more technical jumps and stunts, often associated with increased risk for injury in general.13 Wilkerson and Swanik identified a possible link between neurocognitive deficits and risk for musculoskeletal injuries.14,15 A reaction time composite score â&#x2030;Ľ .545 seconds on ImPACT testing was correlated to a two-fold risk of injury.14 Delayed reaction time is hypothesized to contribute to injury risk due to a diminished capacity for neuromuscular control resulting from deficits in cortically driven reaction time and processing speed.15 This may indicate that improvements in neurocognitive function must be achieved before returning an athlete to sport following a concussion as increased musculoskeletal injury risk may exist. Medical information should also include concussion and orthopedic injury history in order to determine if further evaluation is needed to specifically identify risk factors for further injury.

An important component of return to play decisionmaking following a concussion is neurocognitive testing. Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT, ImPACT Applications, Inc., Pittsburgh, PA) has been shown to be a valid measure for examining deficits in reaction time, processing speed, working memory, attention and concentration in addition to having considerable specificity and sensitivity in identifying neurocognitive deficits following a concussion.16,17 In addition, ImPACT has been used as a reliable tool to determine neurocognitive function and guide decision-making while managing athletes who have sustained a concussion.18 While ImPACT testing is widely used and accepted, reliability and validity of scores between age groups requires further investigation. Despite information that can be gathered from ImPACT testing with regard to neurocognitive deficits, literature supporting a specific rehabilitation program designed to address memory, concentration, processing speed and reaction time following sports-related concussion is lacking. An active recovery program implemented by Gagnon et al has been shown to promote recovery in children and adolescents with post-concussion symptoms.19 The program included gradual progression of aerobic and sports specific activities in addition to sports-specific imagery and visualiza-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 233

tion training that was integrated with an individualized home program.19 However, this active recovery program did not specifically address specific neurocognitive deficits.

The purpose of this case report is to review the presentation of signs and symptoms as well as the evaluation of neurocognitive deficits and development of a neurocognitive retraining program in a female adolescent snowboard athlete following a concussion. In addition, a clinic-based rehabilitation program specifically addressing balance and neurocognitive deficits will be presented.

CASE DESCRIPTION The subject of this case report was a 17-year-old female snowboard cross athlete who was referred from her family medicine doctor for ImPACT testing and vestibular rehab following a concussion. The subject provided signed consent and permission was granted to use her case for publication purposes. She presented to the sports medicine clinic for initial evaluation and treatment thirteen days following a concussion sustained when she caught her heel edge of her snowboard while landing from a jump and subsequently hit her head backwards. She reported wearing a helmet at the time of injury. She was initially evaluated by medical personnel at her local snowboarding club then referred to a doctor trained in concussion management. She denied loss of consciousness but verbalized difficulty in remembering events that occurred during and immediately following the injury. In addition, she reported post-concussion symptoms which included occasional headaches, difficulty with memory and concentration, as well as difficulty falling asleep. She reported a history of four previous concussions (March 2008, November 2009, February 2011, January 2012) leading up to her most recent episode in January 2013. Orthopedic history included injuries to her low back and left cervical spine while shoveling snow eight days prior and well as a right tibial plateau fracture while snowboarding which required surgical intervention three years prior to her recent concussion episode.

and a Dizziness Handicap Inventory (DHI) which has been shown to have excellent reliability and validity when identifying perceived physical, emotional and functional limitations resulting from vestibular dysfunction.20 The DHI is scored 0-100 with a high score of 70-100 indicating a severe perception of handicap, 40-69 moderate, and 39-0 low (Appendix 1). Items are scored according to responses that include never (0), sometimes (2) and always (4).

A higher perception of handicap on the DHI has been correlated with increased episodes of dizziness or unsteadiness in subjects with balance deficits.20 Given the athleteâ&#x20AC;&#x2122;s concussion history and selfreported symptoms, completion of an ImPACT test for post-injury baseline measures was appropriate in order to gather information regarding her neurocognitive status and to assess memory, processing speed, and reaction time given her self-reported difficulty concentrating and with both short and longterm memory. Data from subjective questionnaires and ImPACT testing can be found in Table 1. Information gathered from ImPACT testing would be an important component for development of this athleteâ&#x20AC;&#x2122;s neurocognitive training program. The score report indicated that the athlete was in the lower 6th and 51st percentile for verbal memory and reaction time, respectively, as well as 64th percentile for visual motor speed within her age group. Thus, her training program would likely incorporate exercises addressing these problem areas.

In addition to neurocognitive testing, a thorough post-concussion examination should include cervi-

Table 1.

INITIAL EXAMINATION FINDINGS Subjective questionnaires included a self-reported confidence rating (0-100 scale where 100% represents complete confidence in full return to sports activities) The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 234

cal spine assessment and balance testing in order to identify deficits which may exist in cervical range of motion (ROM) and balance which, if not addressed in a formal rehab program, could contribute to risk for further injury or concussion when returning to sport. Furthermore, restrictions in cervical motion as well as pain could limit the athleteâ&#x20AC;&#x2122;s ability to tolerate reaction training and visual processing activities which would be incorporated in her neurocognitive retraining program. In this case, assessment findings included cervical active and passive ROM which were symmetrical and within normal limits. Balance was assessed using the Balance Error Scoring System (BESS) as this has been supported as both a valid and reliable measure for assessing postural stability.21,22,23 A higher score on the BESS test indicates a high number of balance errors and possible deficits in the somatosensory, visual, and vestibular components of the balance system as tests are performed on both stable and unstable surfaces with eyes either open or closed. This athleteâ&#x20AC;&#x2122;s BESS score was 25 which would be categorized as very

poor according to her closest age group (20-29) reference values where averages for men and women in this age group were 10 and 11, respectively.24 Norms for her age group (10-19) were not available. This indicates that significant balance deficits were present in this subject following concussion and that she would likely benefit from balance training as a part of her rehabilitation program.

INITIAL INTERVENTIONS The initial phase of her rehabilitation program included education on proper transversus abdominis and gluteal muscle activation patterns through isometric and isotonic strengthening exercises with the goal of providing stabilization of the pelvic area during balance exercises (Table 2). These activation patterns were then integrated with BESS testing exercise progressions which included standing with double leg, single leg and tandem stance support on both firm ground and foam surfaces while also challenging visual input by performing exercises with eyes closed. Static balance positions were

Table 2.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 235

Figure 2. Visual tracking exercises using laser pointer to provide a target.

Figure 1. Example of static balance training exercise, tandem stance on foam.

integrated initially, prior to dynamic positions to allow for proper stabilization and muscle activation sequences while challenging all components of the balance system (Figure 1). Visual focus exercises, designed to strengthen muscles around the eyes responsible for dynamic gaze stabilization, were integrated separately to improve focus and concentration while incorporating visual tracking. These exercises have been shown to improve balance as well as both hand and eye coordination and consisted of visual tracking activities at various speeds across multiple planes.25 The athlete was instructed on integration of these exercises in her home program, to be performed daily for three sets of 30 seconds of visual tracking across all planes, as well as daily short and long-term word recall exercises to address memory deficits.

After two treatment sessions which occurred at the rate of one session per week over the course of two weeks, the athlete was able to progress to dual task training exercises without occurrence of headaches or exacerbation of symptoms initially reported. Integration of visual tracking and stabilization exercises with balance exercises has been shown to improve balance scores following a dual task training program.26 Visual tracking exercises also incorporated reaction training which involved tracking a laser pointer on fixed points and locating points that would appear while balancing on both stable and unstable surfaces (Figure 2). In addition, cognitive retraining exercises were combined with these dual tasks to improve outcomes.27,28 Examples would include balance on an unstable surface with perturbations while completing long and short-term word recall, number sequencing, and word association tasks. Reaction training using a laser pointer was only introduced when the athlete could demonstrate good dynamic stability, focus, and concentration on dual tasks, without complaint of headaches. Progressions included performing stability exercises on an unstable surfaces with eyes closed then opening upon verbal command to perform reaction training, which consisted of reaching within and outside base of support towards the location of the laser target (Table 2). Exercises could be made more sports specific by having the athlete balance on a snowboard while performing exercises that challenge the components of the balance system (Figure 3). Perturbations were added if the athlete was able to maintain postural control while

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 236

Figure 3. Sport specific balance training using snowboard on BOSU™.

Figure 4. Example jumping exercises, medial/lateral.

performing dual tasks. These exercises were added to the athlete’s home program. She was advised to complete them daily using a pen light which was provided for reaction training with the assistance of a family member while following the parameters and suggested progressions listed in Table 2.

The last phase of the rehabilitation program included plyometric exercises with reaction training to incorporate the dynamic components of jumping and landing in the sport of snowboarding while addressing deficits in reaction timing (Table 2). The athlete was instructed on proper landing mechanics during forward and lateral jumps with double foot contact.

Jumps were performed to either verbal or visual command. Visual commands would include either laser pointer or hand-direction. Previously mentioned neurocognitive retraining exercises were also integrated during this phase. Progressions would include multi-directional and single-leg jumps with verbal and visual cues (Figures 4,5). The reaction training component was advanced by giving conflicting cues such as pointing left while giving a verbal command of “forward” when the athlete was instructed to follow the verbal command. The athlete was advised to perform the plyometric exercises in her home program three times per week under the supervision of a certified strength and conditioning specialist at her local snowboard club while con-

Figure 5.

tinuing to independently perform word recall and dynamic balance/reaction training activities daily.

OUTCOMES The athlete was seen for a total of 4 visits over the course of six weeks before relocating back to the east coast for the summer season. After six weeks, the athlete completed a follow-up ImPACT test in the clinic. A lower composite score in the reaction time category indicates an overall quicker response to written and visual cues on the ImPACT test. The

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 237

visual motor speed composite score is determined by scores on both the memory and reaction time tasks with a higher composite score indicating improved performance. Verbal and visual memory tasks are scored 0-100 with 100 being a better score. The subject improved in both reaction time and visual processing with scores of .51 and 43.18, respectively, compared to .56 and 42.33 from baseline testing which indicates improvement in both categories (Table 1). There was only slight improvement in verbal memory scores with a lower score on visual memory. This indicates that a greater emphasis on verbal and visual memory activities may have been needed in her daily home program moving forward as well as an increased frequency of physical therapy visits to address these remaining deficits. She still reported symptoms of headaches from reading for more than 20 minutes and when in noisy environments, though not as frequent, and deficits in concentration despite an increased subjective confidence rating. She demonstrated decreased errors on her follow-up BESS test but error score remained elevated which indicates continued vestibular rehabilitation and improved balance scores would be needed before the subject could return to sport. At that time, the subject had not been released by her family physician for participation in snowboarding or contact sports activities due to continued symptoms and was advised to follow-up prior to snowboard season for reassessment. She was instructed to continue with her advanced home program in order to improve balance and memory deficits.

DISCUSSION Proper management of a concussion requires gathering a thorough medical history, a complete subjective report of symptoms, and the use of neurocognitive testing baseline measures in order to determine neurocognitive deficits. Testing environment where a neurocognitive test is administered must be considered. In this case, testing was performed in a quiet, closed-door environment in a sports medicine clinic.

Completion of the ImPACT test in a noisy, crowded environment or in an athleteâ&#x20AC;&#x2122;s home setting, where distractions from unmonitored cell phone or television use could affect reliability and validity of testing results, is not recommended. ImPACT testing should not be the primary source of information when deter-

mining the return to play status in athletes following concussion. Information gathered from neurocognitive testing should be integrated with a program that includes gradual progression in aerobic and sports specific activities as outlined in the National Athletic Trainerâ&#x20AC;&#x2122;s Association position statement on management of sport-related concussion to determine if an athlete is ready for return to sport.22 In addition, it is recommended that athletes undergo baseline neurocognitive testing before each competitive season prior to an incidence of concussion, especially in adolescents whose cognitive development is likely to vary significantly from season to season. In this case study, the subject completed a pre-season baseline neurocognitive test eighteen months prior to her most recent concussion as baseline measures were gathered every two years for athletes within this subjectâ&#x20AC;&#x2122;s age group. These baseline test results were not available or provided by the subject.

Proper fitting equipment and helmet use also play an important role in reducing the risk for traumatic brain injury and possibly decreasing the severity of a concussion. In cases of traumatic head injury, helmet use by injured snowboarders has been poorly documented.11 However, several studies indicate reduced risk for severe head injury when a helmet is worn.12,14,29 Sulheim et al found a 60% reduction in brain injury risk when a helmet was worn in the ski and snowboard population.12 Similarly, helmet use has been shown to significantly reduce the risk of severe or traumatic head injury in the biking and motorcycling populations where the combination of high velocity and falls onto hard surfaces are common.30,31 While this does not imply that a concussion can be prevented when wearing a helmet, it would be prudent to advise snowboard athletes, as well as those that participate in sports involving aerial maneuvers and/or high velocity activities such as skateboarding, freestyle skiing, or motorcycling, to wear a helmet given the possibility of sustaining a head injury when participating in their sport or activity. Educating coaches and parents on the importance of helmet use is also advised.

While incorporating balance, neurocognitive retraining, and reaction training progressions, the medical practitioner should be sensitive to overloading the sensory and motor systems. Integrating excessive stimuli in an athlete during post-concussion rehab

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 238

may result in increased symptoms and delay rehab progressions attempted through dual task training.

Slowed reaction time during these activities should be expected as attention is divided between balance and cognitive tasks with postural control being prioritized.32,33 In this case report, exercises were only progressed as tolerated and if the subject demonstrated the ability to maintain postural control while successfully completing dual tasks challenging the visual, somatosensory and vestibular components of the balance system.

In this case report, the subjectâ&#x20AC;&#x2122;s reaction time composite score was above the previously established cut-off which may indicate a predisposition to musculoskeletal injury that may have contributed to her recent concussion given the athlete reported an injury to her low back and cervical spine one week prior. Her medical history also indicates a prior surgery to her right lower extremity. With this being said, gathering of a thorough medical history should include considerations of both orthopedic injury and concussion history. Also, given the indication from previous research that musculoskeletal injury risk may be increased following a concussion, it would be prudent to assess both neurocognitive function and functional movement patterns. Following assessment, implementation of an appropriate musculoskeletal and neurocognitive training program which addresses these risk factors would be beneficial before returning an athlete to sport following a concussion.

Additional research which further investigates the combined integration of neurocognitive and musculoskeletal training programs within post-concussion rehabilitation programs may be beneficial in addressing various deficits which may put athletes returning to sport to quickly at risk for injury.

Return to sport decision making should address the psychological components of injury and the rehabilitation process. Subjective ratings of confidence and use of questionnaires to identify functional limitations, in addition to symptom checklists, balance scores, neurocognitive testing, and response to activity progressions, should assist in guiding return to sport decision making following a concussion. An athleteâ&#x20AC;&#x2122;s decreased levels of confidence in returning to sport could be indicative of psychological limitations associated with perceived negative life events such as previous injury

or personal stress. If an athlete returns to sport too quickly without his or her psychological limitations being addressed, injury may result due to a narrowing of peripheral vision as well as subsequent delays in visual processing and reaction timing in response to environmental stimuli.34,35 Limitations of this case include reassessment after only four treatment sessions and a program length of six weeks due to athlete relocation. In addition, baseline ImPACT testing results closer to the time of her most recent concussion episode were lacking.

Outcomes of this case report are of a single subject only and cannot be applied with confidence to other athletes or athletic populations.

CONCLUSIONS This case report presents an integrated rehabilitation program that specifically addresses neurocognitive deficits that are identified on ImPACT testing following concussion. A program which incorporates dual-task training by combining balance and reaction training activities may improve both balance and neurocognitive function in the categories of reaction timing and visual motor speed processing, based upon the findings of this case report. Future research should investigate the benefits of a combined neurocognitive and balance training program over a longer period of time as well as the effectiveness of computer-based and visual training activities as they relate to improving both short and long-term memory, visual processing, and reaction timing in athletes following a concussion. Additionally, more research is needed investigating the risk for concussion in sports such as snowboarding, freestyle skiing, skateboarding and motorbiking which combine high velocity with aerial stunts and tricks.

REFERENCES 1. Gilchrist J, Thomas K, Xu L, et al. Nonfatal sports and recreation related traumatic brain injuries among children and adolescents treated in emergency departments in the United States, 20012009. MMWR 2011: 60;1337-1342.

2. Gessel L, Fields S, Collins C, et al. Concussions among United States high school and collegiate athletes. J Athl Train 2007;42:495-503.

3. Marar M, McIllvain N, Fields S, et al. Epidemiology of concussions among United States high school athletes in 20 sports. Am J Sports Med 2012; 40:747-755.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 239

4. Meehan W, d’Hemecourt P, Comstock, R. High school concussions in the 2008-2009 academic year: mechanism, symptoms, and management. Am J Sports Med 2010;38:2405-2409.

20.

5. Bladin C, McCrory P, Pogorzelski A. Snowboarding injuries. Sports Med 2004;34:133-138.

21.

6. Davidson T, Laliotis A. Snowboarding injuries: a four-year study with comparison with alpine ski injuries. West J Med 1996;164:231-237.

22.

7. Dohjima T, Sumi Y, Ohno T, et al. The dangers of snowboarding: a 9-year prospective comparison of snowboarding and skiing injuries. Acta Orthop 2001;72:657-660.

23.

8. Idzikowski J, Janes P, Abbott P. Upper extremity snowboarding injuries: ten-year results from the Colorado snowboard injury survey. Am J Sports Med 2000;28:825-832.

9. Langran M, Selvaraj S. Snow sports injuries in Scotland: a case-control study. Br J Sports Med 2002;36:135-140.

24.

25.

10. Macnab A, Smith T, Macnab M. Effect of helmet wear on the incidence of head/face and cervical spine injuries in young skiers and snowboarders. Inj Prev 2002;8:324-327.

26.

11. McBeth P, Ball C, Mulloy H, et al. Alpine ski and snowboarding traumatic injuries: incidence, injury patterns and risk factors for 10 years. Am J Surg 2009;197:560-564.

27.

12. Sulheim S, Holme I, Ekeland A, et al. Helmet use and risk of head injuries in alpine skiers and snowboarders. JAMA 2006;295:919-924.

29.

28.

13. Fountain J, Meyers M. Skateboarding injuries. Sports Med 1996;22:360-366.

14. Wilkerson G. Neurocognitive reaction time predicts lower extremity sprains and strains. Int J Athl Ther Train 2012;17:4-9.

30.

15. Swanik C, Covassin T, Stearne D, et al. The relationship between neurocognitive function and noncontact anterior cruciate ligament injuries. Am J Sports Med 2007;35:943-948.

31.

16. Iverson G, Gaetz M, Lovell M, et al. Relation between subjective fogginess and neuropsychological testing following concussion. J Int Neuropsych Soc 2004;10:904-906.

32.

33.

17. Schatz P, Pardini J, Lovell M, et al. Sensitivity and specificity of the ImPACT Test Battery for concussion in athletes. Arch Clin Neuropsych 2006;21:91-99.

34.

18. Lovell M, Collins M, Iverson G, et al. Recovery from mild concussion in high school athletes. J Neurosurg 2003;98:296-301.

35.

19. Gagnon I, Galli C, Friedman D, et al. Active rehabilitation for children who are slow to recover

following sport-related concussion. Brain Injury 2009;23:956-964.

Jacobson G, Newman C. The development of the Dizziness Handicap Inventory. Arch Otolaryngol Head Neck Surg 1990;116:424-427.

Guskiewicz K, Ross S, Marshall S. Postural stability and neuropsychological deficits after concussion in collegiate athletes. J Athl Train 2001;36:263-273.

Guskiewicz K, Bruce S, Cantu R, et al. National Athletic Trainers’ Association Position Statement: Management of Sport-Related Concussion. J Athl Train 2004;39:280-297.

Riemann B, Guskiewicz K, Shields E. Relationship between clinical and forceplate measures of postural stability. J Sport Rehabil 1999;8:71-62.

Iverson G, Koehle M. Normative data for the Balance Error Scoring System in adults. Rehab Res Pract 2013.

McLeod B. Effects of Eyerobics visual skills training on selected performance measures of female varsity soccer players. Perceptual and Motor Skills 1991;72: 863-866.

Broglio S, Tomporowski P, Ferrara M. Balance performance with a cognitive task: a dual-task testing paradigm. Med Sci Sports Exerc 2005;37:689695.

Gillen G. Cognitive and Perceptual Rehabilitation: Optimizing Function. St Louis, MO: Mosby Inc; 2009.

Neistadt M. Perceptual retraining for adults with diffuse brain injury. Am J Occup Ther 1994;48:225-233.

Hagel B, Pless I, Goulet C, et al. Effectiveness of helmets in skiers and snowboarders: case-control and case crossover study. Br J Sports Med 2005;330:281.

Davidson J. Epidemiology and outcome of bicycle injuries presenting to an emergency department in the United Kingdom. Eur J Emerg Med 2005;12:24-29.

Liu B, Ivers R, Norton R, Boufous S, Blows S, Lo S. Cochrane Database Syst Rev 2008;1.

Resch J, May B, Tomporowski P, et al. Balance performance with a cognitive task: a continuation of the dual-task testing paradigm. J Athl Train 2011; 46:170.

Teel E, Register-Mihalik J, Blackburn J, et al. Balance and cognitive performance during a dual-task: preliminary implications for use in concussion assessment. J Sci Med Sport 2013;16:190-194.

Andersen M, Williams J. Athletic injury, psychosocial factors and perceptual changes during stress. J Sports Sci 1999;17:735-741.

Williams J, Andersen M. Psychosocial influences on central and peripheral vision and reaction time during demanding tasks. Behav Med 1997;22:160-167.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 240

Appendix 1

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 241

IJSPT

CLINICAL COMMENTARY

PEDIATRIC SPORTS SPECIFIC RETURN TO PLAY GUIDELINES FOLLOWING CONCUSSION Keith H. May, PT, DPT, SCS, ATC, CSCS1 David L. Marshall, MD1 Thomas G. Burns, PsyD, ABPP/CN1 David M. Popoli, MD1 John A. Polikandriotis, PhD, MBA, MPH, FACHE1

ABSTRACT Purpose/Background: In 2010, the American Academy of Pediatrics officially adopted the recommended return to play guidelines proposed by the International Conference on Concussion in Sport. The guidelines include a six-step process that provides structure to guide an athlete who is recovering from a concussion in a gradual return to play (RTP) by allowing participation in increasingly difficult physical activities. Unfortunately, the guidelines fail to take into account the variability that occurs within different sports and the resulting challenges medical professionals face in making sure each athlete is able to withstand the rigors of their specific sport, without return of symptoms. Therefore, the purpose of this clinical commentary is to expand upon the current general consensus guidelines for treatment of concussed pediatric athletes and provide sport specific RTP guidelines.

Description of Topic: The intention of the sport specific guidelines is to maintain the integrity of the current six-step model, add a moderate activity phase highlighted by resistance training, and to provide contact and limited contact drills specific to the athlete’s sport and/or position. The drills and activities in the proposed sevenstep programs are designed to simulate sport specific movements; the sports include: football, gymnastics, cheerleading, wrestling, soccer, basketball, lacrosse, baseball, softball, and ice hockey. These activities will provide sports specific challenges to each athlete while simultaneously accomplishing the objectives of each stage of the RTP progression. The final RTP determination should occur with documented medical clearance from a licensed healthcare provider who has been trained in the evaluation and management of concussions.

Discussion/Relation to Clinical Practice: There have been significant strides in the management and care of concussed athletes. However, there continues to be a lot of confusion among, athletes, parents, and coaches regarding the proper management of an athlete with a concussion, particularly in the pediatric population. In an effort to eliminate ambiguity and help further promote adherence to the RTP guidelines, the authors developed several sports-specific RTP guidelines.

Level of Evidence: 5 Keywords: Concussion, pediatric, return to play guidelines, sports

1

Children’s Healthcare of Atlanta, Atlanta, GA, USA

CORRESPONDING AUTHOR Keith H. May, PT, DPT, SCS, ATC, CSCS Clinical Outcomes Project Manager Sports Medicine Program Children’s Healthcare of Atlanta 5445 Meridian Mark Rd. NE Atlanta, GA 30342 office # (404) 785-5701 Email: keith.may@choa.org

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 242

BACKGROUND/PURPOSE Attention to sports related head injuries, specifically concussions, has increased over the last ten years.1 The increased interest is likely multi-factorial, occurring due to the impact of concussions on high profile professional athletes coverage in the popular media, and the large number of teens participating in contact and collision sports. More than half of all high school students, over 7.7 million boys and girls, participated in sports during the 2012-2013 school year compared to 6.8 million during the 2002-2003 school year.2 Consequently, the overall number of reported head injuries continues to rise. In fact, Langlois et al reported that at least 1.6-3.8 million sports related concussions occur each year in the United States.3 While the majority of concussion symptoms resolve within 10 days to two weeks,4 the consequences of returning an athlete to play too soon following a concussion are now beginning to be understood.

For example, there is a significant risk for a second concussion whose compounding effects can be detrimental to the adolescent athlete.5-13 In 2001, a multidisciplinary group of sport and medical professionals met in Vienna, Austria at the International Conference on Concussion in Sport (ICCS) and has since met three additional times with the specific objective of improving the evaluation, management, and return to play of concussed athletes.14-17 Interestingly, the pediatric and adolescent athlete was not considered until the 2008 conference that occurred in Zurich, Switzerland where three significant questions were raised: 1) Which symptom reporting scale is the most appropriate for this age group?; 2) Which tests are useful and how often should baseline testing be performed?; and 3) What are the most appropriate return to play criteria for the elite and non-elite child and adolescent athlete?

In 2012 and in response to the 2008 conference, the ICCS developed the child SCAT 3 (for ages 5-12) for sideline use, recommended that neurophysiological testing be used broadly the same as adults with consideration made toward age appropriate cognitive development, recommended that children make a complete return to school prior to a return to play, and recommended a more conservative return to play progression, secondary to a childâ&#x20AC;&#x2122;s physiologi-

Table 1. Graduated Return-to-Play Protocol, with additional Step 618

cal response to a head injury and their tendency to take longer to recover.17 In 2010, the American Academy of Pediatrics (AAP) published basic concussion management guidelines for children and adolescents, adapted from the ICCS recommendations that emphasized a graduated return to play (RTP) protocol and the importance of having an athlete follow a stepwise progression in their RTP.18 Table 1, adapted from the AAP guidelines, shows the recommended RTP progression.

According to the recommended protocol, a concussed athlete begins the 6-step protocol and moves through the progression at 24-hour intervals as long as no symptoms occur. If an athlete develops symptoms the progression should be stopped and the athlete must be returned to the previous phase. The final RTP determination should occur with documented medical clearance from a licensed healthcare provider who has been trained in the evaluation and management of concussions.

It is important to recognize that the mechanisms of concussive injury and force of collision vary among sports. In football, for example, helmet-to-helmet collisions are common, whereas contact from a stick, puck or ball can occur in ice hockey, lacrosse, or soccer. For this reason, every concussion is unique and athletic medical providers should consider sport specific RTP guidelines utilizing symptom reports, as well as cognitive and balance examination data to track recovery. Ultimately, this will assist in developing detailed understanding regarding how and when to return pediatric athletes back their sports activities. Therefore, the purpose of this clinical commentary is to expand upon the current general consensus

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 243

guidelines for treatment of concussed pediatric athletes and provide sport specific RTP guidelines.

DESCRIPTION OF TOPIC The following sports specific RTP criteria developed by a multidisciplinary sports medicine team at Childrenâ&#x20AC;&#x2122;s Healthcare of Atlanta was written and implemented into the Atlanta, GA metro service area in 2012 (Appendices 1-10). The intention was to maintain the integrity of the current 6-step basic progression suggested by the ICCS and adopted by the AAP, spanning the time period from no physical activity to full RTP. The authors propose adding a moderate activity step highlighted by resistance training and modifying steps three and four to include noncontact and limited contact drills specific to the athleteâ&#x20AC;&#x2122;s sport.

Assessing an athleteâ&#x20AC;&#x2122;s tolerance to resistance training is important because weight training can increase intracranial pressure and exacerbate post concussive symptoms.19 Resistance training should be introduced with low weight/high repetition exercises.20 The specific sports chosen for this new 7step program were known to be of high risk for head injury and included football, gymnastics, cheerleading, wrestling, soccer, basketball, lacrosse, baseball, softball and ice hockey. Each sport was considered for drills and activities that could be completed by the athlete that would simulate sport specific movements while simultaneously accomplishing the objectives of each stage of the RTP progression. As with the basic guidelines, each step represents a 24hour period unless an athlete develops symptoms. A pediatric or adolescent athlete should begin the RTP progression once they have achieved a full return to school (cognitive activities). If symptoms occur, the progression should be stopped and the athlete returned to the previous phase where symptoms did not occur. A list of common concussion symptoms described by the AAP is included in Table 2.

To reiterate, the final RTP determination should occur with documented medical clearance from a licensed healthcare provider who has been trained in the evaluation and management of concussions.

This could include a physician, nurse practitioner, physician assistant, certified athletic trainer, or board certified sports physical therapist.

Table 2. Signs and Symptoms of a Concussion18

DISCUSSION The pathophysiology, recognition and treatment of concussions are becoming far better understood than in years past. Most concussion management programs now stress cognitive rest, physical rest, the use of neurocognitive testing, and utilization of return to play guidelines. Despite these improvements in the care of athletes, there continues to be a lot of confusion among athletes, parents, and coaches as to the proper management of a concussion, particularly those that occur in children. In an effort to eliminate ambiguity and help further promote adherence to the RTP guidelines, the authors developed these sequential sports-specific RTP guidelines. Further research is warranted in order to validate these guidelines and their potential impact on return to play adherence and overall success. Adherence to even the current general return to play recommendations continues to be a challenge in the pediatric and adolescent sporting community. In 2009, Yard and Comstock found that one in six athletes failed to follow a standardized RTP guideline and thus frequently returned to their sport prematurely.21 Furthermore, Hollis et al reported that in a group of 296 rugby athletes with suspected concussions only 66 returned to play with medical clearance.12 Similarly, Sye et al reported 145 of 187 rugby players were only compliant with the initial rest period.23 Of special concern is that there are currently no suggested RTP guidelines for athletes under the age of 13. The consensus guidelines are described to be applicable for adolescents 13 years of age and older.

An age appropriate physical, cognitive testing and symptom checklist is recommended as a component of the assessment as patients below age 13 tend to report concussion symptoms different from adults.17 Consensus in the literature is that those who manage a younger athlete with a concussion should be prepared to extend the recovery timeline.17,24 The

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 244

extended time is a product of the different physiological response that children and adolescents demonstrate as a result of a concussion (e.g. diffuse cerebral swelling). The actual recovery time may vary based on the individual patient.17,24 Additionally, RTP guidelines may need to be adjusted for those who have experienced a prior head injury. Multiple authors have described that those who have suffered a prior injury have up to a 5.8 fold increased rate of re-injury.6-13 Therefore, treating an athlete with multiple concussions involves emphasizing the need to consider the long-term consequences and recovery prior to RTP.25-27 Lastly, many states have passed legislation designed to address the growing concern of traumatic brain injuries and concussion among young athletes. In addition to the legislative efforts that may govern RTP guidelines, a team approach that involves health care providers, parents, athletes, and coaches is key for the long-term health of the athlete.

REFERENCES 1. Graham R, Rivara FP, Ford MA, Spicer CM, eds.

Sports Related Concussions in Youth: Improving the Science, Changing the Culture. Washington DC: National Academies Press; 2014.

2. National Federation of State High School Associations. 2012-2013 high school athletics participation survey. http://www.nfhs.org/.

Accessed September 8, 2013.

3. Langlois JA, Rutland-Brown W, Wald MM. The epidemiology and impact of traumatic brain injury: a brief overview. J Head Trauma Rehabil. 2006 SepOct;21(5):375-378.

4. D`Hemecourt P. Subacute symptoms of sportsrealted concussion: outpatient management and return to play. Clin Sports Med. 2011;30:63-72.

8. Emery C, Kang J,Shrier I, et al. Risk of injury associated with bodychecking experience among youth hockey players. CMAJ 2011;83:1249-56.

9. Guskiewicz KM, Marshall SW,Bailes J, et al. Recurrent concussion and risk of depression in retired professional football players. Med Sci Sports Exerc. 2007;39:903-9.

10. Guskiewicz KM, McCrea M, Marshall SW, et al. Cumulative effects associated with recurrent concussion in collegiate football players: The NCAA concussion study. JAMA 2003;290:2549.

11. Guskiewicz KM, Weaver NL, Padua DA, et al. Jr. Epidemiology of concussion in collegiate and high school football players. Am J Sports Med. 2000;28: 643-50.

12. Hollis SJ, Stevenson MR, McIntosh AS, et al. Incidence, risk, and protective factors of mild traumatic brain injury in a cohort of Australian nonprofessional male rugby players. Am J Sports Med. 2009;37:2328-33.

13. Kristman VL, Tator CH, Kreiger N, et al. Does the apolipoprotein epsilon 4 allele predispose varsity athletes to concussion? A prospective cohort study.

Clin J Sport Med. 2008;18:322-8.

14. Aubry M, Cantu R, Dvorak J, et al. Summary and agreement statement of the ďŹ rst international conference on concussion in sport, Vienna 2001. Br J Sports Med. 2002;36:6-7.

15. McCrory P, Johnston K, Meeuwisse W, et al.

Summary and agreement statement of the 2nd International Conference on Concussion in Sport, Prague 2004. Br J Sports Med. 2005;39:196-204.

16. McCrory P, Meeuwisse W, Johnston K, et al.

Consensus Statement on Concussion in Sport: the 3rd International Conference on Concussion in Sport held in Zurich, November 2008. Br J Sports Med. 2009;43 Suppl 1:i76-90.

5. McCrea M, Guskiewicz K, Randolph C, et al. Effects of a symptom free waiting periods on clinical outcome and risk of reinjury after sport-related concussion. Neurosurgery. 2009;65(5):876-882.

17. McCrory P, Meeuwisse W, Aubry M, et al. Consensus statement on Concussion in Sport-The 4th International Conference on Concussion in Sport held in Zurich, November 2012. J Sci Med Sport 2013;16:178-89.

6. Schulz MR, Marshall SW, Mueller FO et al. Incidence and risk factors for concussion in high school athletes, North Carolina, 1996-1999. Am J Epidemiol 2004;160:937-44.

18. Halstead ME, Walter KD, and the Council on Sports Medicine and Fitness. Sports-Related Concussion in Children and Adolescents. Pediatrics. 2010; 126(3): 597-615.

7. Colvin AC, Mullen J, Lovell MR, et al. The role of concussion history and gender in recovery from soccer-related concussion. Am J Sports Med. 2009;37:1699-704.

19. Haykowsky M, Eves N, Warburton D, et al.

Resistance exercise, theValsalva maneuver, and cerebrovascular transmural pressure. Med Sci Sports Exerc. 2003;35:65-68.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 245

20. Kissick J, Johnston KM. Return to play after a concussion principles and practice. Clin J Sport Med. 2005;15:426-431.

24. Karlin AM. Concussion in the pediatric and adolescent population: “Different population, different concerns”. Pm&R. 2011;3:S369-79.

21. Yard EE, Comstock RD. Compliance with return to play guidelines following concussion in US high school athletes, 2005-2008. Brain Inj. 2009;23:888-98.

25. Harmon KG, Drezner JA, Gammons M, et al.

American Medical Society for Sports Medicine position statement: concussion in sport. Br J Sports Med. 2012;47:15-26.

22. Jack K, McLean SM, Moffett JK, Gardiner E. Barriers to treatment adherence in physiotherapy outpatient clinics: A systematic review. Man Ther.

2010;15:220-8.

23. Sye G, Sullivan SJ, McCrory P. High school rugby players’ understanding of concussion and return to play guidelines. Br J Sports Med. 2006;40:1003-5.

26. Laker SR. Return-to-play decisions. Phys Med Rehabil Clin N AM. 2011;22:619-34.

27. Doolan AW, Day DD, Maerlender AC, Goforth M, Gunnar Brolinson P. A Review of Return to Play Issues and Sports-Related Concussion. Ann Biomed Eng. 2011;40:106-13.

Appendix 1

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 246

Appendix 2

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 247

Appendix 3

It is recommended that you seek further medial a en on if you fail more than 3 a empts to pass a stage

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 248

Appendix 4

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 249

Appendix 5

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 250

Appendix 6

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 251

Appendix 7

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 252

Appendix 8

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 253

Appendix 9

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 254

Appendix 10

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 255

IJSPT

CLINICAL COMMENTARY

RADIOLOGICAL EXAMINATION OF THE HIP  CLINICAL INDICATIONS, METHODS, AND INTERPRETATION: A CLINICAL COMMENTARY Amir C. Reis, PT, MSc Candidate1 Nayra D.A. Rabelo, PT, MSc Candidate1 Rafael P. Pereira, PT2 Giancarlo Polesello, MD, PhD3 Robroy L. Martin, PT, PhD4,5 Paulo Roberto Garcia Lucareli, PT, PhD6 Thiago Y. Fukuda, PT, PhD2,7

ABSTRACT There is a growing interest in musculoskeletal rehabilitation for young active individuals with non-arthritic hip pathology. History and physical examination can be useful to classify those with non-arthritic intraarticular hip pathology as having impingement or instability. However, the specific type of deformity leading to symptoms may not be apparent from this evaluation, which may compromise the clinical decision-making. Several radiological indexes have been described in the literature for individuals with non-arthritic hip pathology. These indexes identify and quantify acetabular and femoral deformities that may contribute to instability and impingement. The aim of this paper is to discuss clinical indications, methods, and the use of hip radiological images or radiology reports as they relate to physical examination findings for those with non-arthritic hip pathology.

Level of evidence: 5 Key words: Examination, Femoroacetabular impingement (FAI), imaging, labrum

1

MSc postgraduate student, Universidade Nove de Julho, São Paulo, SP, Brazil 2 Irmandade da Santa Casa de Misericórdia, Rehabilitation Service, São Paulo, SP, Brazil 3 Irmandade da Santa Casa de Misericórdia, Orthopaedic and Traumatologic Department, São Paulo, SP, Brazil 4 Duquesne University, Pittsburgh, PA, USA 5 University of Pittsburgh Centers for Sports Medicine, Pittsburgh, PA, USA 6 Professor at Universidade Nove de Julho, Rehabilitation Service, São Paulo, SP, Brazil 7 Centro Universitário São Camilo, São Paulo, SP, Brazil

CORRESPONDING AUTHOR Thiago Yukio Fukuda Rua Dr. Cesário Motta Jr (Setor de Fisioterapia), 112, CEP: 01221-020 São Paulo, SP, Brazil Email: tfukuda10@yahoo.com.br

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 256

INTRODUCTION There is a growing interest in musculoskeletal rehabilitation for young active individuals with nonarthritic hip pathology. Physical therapists generally base their assessment of those with hip pathology on history and physical examination.1 However, bony abnormalities may influence the patientâ&#x20AC;&#x2122;s prognosis and therefore may need to be identified.

When abnormalities of bone morphology are present, direct repercussions on the biomechanics of the hip and adjacent joints can occur.2 Several radiological indexes have been described in the literature for individuals with non-arthritic hip pathology.3,4 The aim of this paper is to discuss clinical indications, methods, and interpretation of hip radiological images as they relate to physical examination findings for those with non-arthritic hip pathology.

There are a limited number of evaluation algorithms for those with hip related symptoms. An evaluation algorithm and classification based treatment system have recently been described to guide physical therapists in the management of individuals with hip pain, including those with non-arthritic related pathology.5,6 This evaluation includes considerations for non-musculoskeletal, lumbosacral spine, extraarticular, and intra-articular sources of pain. Intraarticular pathologies for individuals with non-arthritic hip pain are further classified as impingement and hypermobility as outlined in Figure 1. While evidence

Figure 1. Evaluation algorithm for young active individuals.

to support the use of this algorithm is lacking it does relate to relevant non-arthritic radiographic abnormalities that have been described.

History and physical examination are commonly used to assess for non-musculoskeletal and lumbosacral spine pathology as potential sources of hip pain as described in detail elsewhere.5-12 Once non-musculoskeletal and lumbar spine pathology are ruled out as potential sources of hip pain, the clinician must determine if there is an intra- and/ or extra-articular source of symptoms. The Flexion-Abduction-External Rotation (FABER), Internal Range of Motion with Over-Pressure (IROP), and Scour tests may be useful in this capacity.13-15 The FABER and IROP tests have sensitivity values in identifying individuals with intra-articular pathology of 0.82 and 0.91, respectively.14 The Scour test has sensitivity values ranging between 0.62 and 0.91 in identifying those with intra-articular pathology.13,15 Extra-articular pain generators, such as musculotendinous pathologies, should not be provoked with the FABER, IROP, and Scour tests. Musculotendinous pathologies, including muscle strains and/or tendon disorders, should be painful with palpation, stretching, and resisted movements directed at the involved muscle and/or tendon. If the source of pain is solely from intra-articular origin, palpable pain is rarely present.16 If FABER, IROP, and Scour tests are positive, the source of pain is likely due to intra-articular sources.7,17 Once it is determined that the source of pain is intra-articular, additional tests can be conducted in order to further classify individuals into an impingement or hypermobility classification.

FEMOROACETABULAR IMPINGEMENT Two types of femoroacetabular impingement (FAI) have been described; cam and pincer types.18 Cam impingement results from an abnormal bump, thickening, and/or loss of femoral-head neck offset which can be localized anteriorly, superiorly, posteriorly, and/or inferiorly.19 Cam deformities cause labral compression and sheer forces leading to acetabular cartilage damage.19,20 The location of the deformity and direction of hip movement will determine the specific location of injury. A cam deformity at the

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 257

anterior-superior femoral head-neck junction will compress the anterior-superior labrum during the combined motion of hip internal rotation, flexion, and adduction. Posterior head-neck deformities can cause posterior-superior labral compression with hip external rotation and extension, while head-neck deformities that are located superiorly can cause superior labral compression with hip abduction.21 Differing from cam impingement, pincer type impingement results from an acetabular deformity.

Focal or global over coverage of the femoral head by the acetabulum are terms used to further describe pincer impingement.19 Superior focal over coverage results from the anterior and superior acetabular rim extending laterally over the femoral head. This deformity can cause the femoral head-neck junction to abut the anterior-superior labrum when the hip moves into internal rotation, flexion, and adduction.21 Excessive acetabular retroversion and anteversion are also potential causes of focal over coverage. Acetabular retroversion results in anterior over coverage but posterior under coverage of the femoral head.

This anterior over coverage will cause the head-neck junction to come into contact with anterior-superior labrum when the hip is internally rotated in flexion.

Conversely, acetabular anteversion causes posterior over coverage but anterior under coverage with the head-neck junction abutting the posterior-superior labrum in a position of hip external rotation and extension.21 Coxa profunda and protrusio are acetabular global over coverage deformities.19 Depending on the severity of the over coverage, labral damage from compression can occur in locations where the headneck junction comes into contact with the labrum.

Acetabular deformities can also cause the femoral head to be levered out of the acetabulum and result in cartilage and/or labral pathology in a location opposite to the labral compression. These types of injuries are called ‘countra-coup’ lesions.22,23 In addition to cam and pincer type FAI, mechanical impingement may be caused by rotational deformities of the femur in the transverse plane.24 The femoral head-neck is normally rotated approximately 15⬚ anteriorly. Decreased anteversion is noted when the femoral head-neck is rotated less than 15⬚. The anterior-superior head-neck junction will be closer to the anterior rim of the acetabulum when angle

of anteversion is decreased. Therefore, movements that incorporate hip internal rotation in 30-60⬚ of flexion may cause the femoral head-neck junction to compress the anterior-superior labrum. Excessive femoral anteversion is said to be present when the femoral head-neck is rotated greater than 15⬚ anteriorly. When anteversion is greater than 30⬚ the posterior head-neck junction will be close to the posterior rim of the acetabulum and compress the posterior-superior labrum with the femoral head-neck junction with combined hip external rotation and extension.21 Prospective studies have demonstrated potential diagnostic indicators of FAI. These studies have found those with FAI commonly complain of an insidious onset of sharp or aching groin pain that limits activity.25,26 Those with FAI also have physical examination findings of limited hip flexion, internal rotation, and abduction range of motion and positive Flexion-Adduction-Internal Rotation Impingement (FADDIR) and FABER tests.4,27-29 Special tests to identify the specific source of impingement as either anterior, superior, and/or posterior have been developed and include two dynamic impingement tests.30 The Dynamic Internal Rotation Impingement test (DIRI) circumducts the hip through an arc of flexion, adduction, and internal rotation in order to cause contact of the femoral head-neck junction with the anterior and anteriorsuperior rim of acetabulum.30 The dynamic external rotation impingement test (DEXTRI) circumducts the hip through an arc of extension, abduction, and external rotation in order to cause contact of the femoral head-neck junction with the posterior and posterior-superior rim of acetabulum.30 The position(s) that recreate the pinching pain can be used to identify the potential location of impingement.

While the DIRI and DEXTRI have been described to potentially assess for the source of Cam and Pincer impingements, Craig’s test may be used to identify those with abnormal femoral version. This method involves positioning an individual prone and flexing the knee to 90 degrees. The greater trochanter is then palpated as the thigh is internally and externally rotated, until the greater trochanter is at its most prominent position laterally. Femoral anteversion is

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 258

measured as the angle formed by the long axis of the lower leg and the vertical, and is quantified using a goniometer or inclinometer.31 A normal test is a position of 15⬚ hip internal rotation when the greater trochanter is parallel to the floor/table. Individuals in a position of more than approximately 15⬚ may be considered to have increased femoral anteversion, which would lead to a greater anterior exposure of the femoral head.

INSTABILITY Labral-chondral pathology can also be caused by either focal rotational or global hip laxity.32 Although there are many causes of instability27 in a young active population, localized laxity of ligamentous and capsular structures is commonly caused by excessive repetitive forceful hip rotation. This type of injury is defined as focal rotational instability.33-35 The most common injury is iliofemoral ligament laxity caused by repetitive forceful hip external rotation beyond the limit of normal motion. Although less common, excessive internal rotation could potentially lead to ishiofemoral ligament laxity.30 Instability is usually combined with some form of acetabular undercover.36 This can be from acetabular anteversion, retroversion, or global under coverage. Although any malformation of the acetabular shape could be termed dysplasia, hip dysplasia is a term commonly associated with global under coverage resulting from a shallow acetabulum. Abnormal loading of the anterior-superior labrum and subsequent labral-chondral damage can occur with either focal rotational or global hip laxity.34,35,37 Regarding the femoral head neck deformities, coxa valgum may also lead to instability and abnormal loading of the superior labrum, thus contributing to labral-chondral pathology(38,39).

The diagnosis of instability can be suspected when complaints of hip pain are associated with findings of hypermobility. Individuals may note movement dependent hip instability or apprehension. Clinically, range of motion measurements, the log roll test, and Beighton Scale can be used to assess for hypermobility. Hip range of motion measures that exceed established normative values or that are increased compared to the uninvolved side without the presence of an anteverted or retroverted femur should raise suspicion of hypermobility. Signs for

select iliofemoral ligament laxity include increased hip external rotation but normal internal rotation range of motion.40 The log roll test specifically assesses rotational motion and is used to observe asymmetrical increases in internal and external rotation as well as quality of end-feel.30 Excessive external rotation motion with softer than normal end-feel would indicate iliofemoral ligament laxity.

Additionally, the Beighton Scale can be used to identify those with general ligament laxity.41 Using this scale three or more of the following would indicate general ligament laxity: extension of the 2nd metacarpal phalangeal joint beyond 90⬚, flexion of the thumb to the forearm, extension of the knee beyond 10⬚, extension of the elbow beyond 10⬚, and palms touching the floor while bending at the waist.

History and physical examination can be useful to classify young active individuals with non-arthritic hip pathology as having impingement or instability.

However, the specific type of deformity leading to symptoms may not be apparent from this evaluation. For example, an individual may have signs and symptoms consistent with impingement, including a positive DIRI. While FAI would be suspected, the bony deformity being an anterior-superior cam, acetabular retroversion, or global over coverage, may be difficult to determine solely from the physical examination. Also, prognosis for conservative care may be linked to the degree of boney deformity. An individual with signs and symptoms consistent with instability and excessive global acetabular under coverage may have a worse prognosis than an individual with similar signs and symptoms but only a slight degree of under coverage. Therefore, physical therapists may use the results of radiographic assessment of acetabulum and femur to help verify the classification; more precisely identify the type of bony deformity, and assist in determining a potential prognosis based on the degree of the deformity.17 While there are not absolute values that define how the degree of deformity will relate to prognosis, severe deformities are likely to be associated less favorable outcomes.

RADIOGRAPHIC ASSESSMENT Radiographic examination is widely used because it is readily available, simple, and fairly inexpensive.

However, as with any tool it must be performed

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 259

Figure 2. Anteroposterior X-ray of the pelvis in neutral position (A). The black line indicates the distance between the coccyx and the public symphysis. The acceptable distance is considered to be between 3 and 5 cm (B).

properly. Standard conventional radiographic imaging for femoroacetabular investigation includes two radiographs: an anteroposterior (AP) view and an axial cross-table view.4 Some alternatives to the axial view are the Ducroquet and Dunn radiographs and because they provide similar information which will not be discussed. In the case of an anteroposterior (AP) X-ray, neutral rotation of the pelvis in the transverse plane is defined when the lower end of the coccyx is located perpendicular to the pubic symphysis (Figure 2). In relation to sagittal plane, neutral pelvic inclination is established when the distance between the coccyx and pubic symphysis is approximately 3 cm for men and 5 cm for women.4,42 Determining that the radiograph was taken with neutral pelvic inclination is critical and must be done before the radiograph can be interpreted. An AP radiograph that does not follow this standardization cannot reliably diagnose boney deformities of the hip joint.4 The cross-table radiograph is performed with the hip in neutral position or internally rotated at 15 degrees in order for the femoral neckhead junction to be appropriately visualized.43 ACETABULAR CONDITIONS Acetabular depth The AP radiograph can be used to identify abnormal acetabular morphology in terms of focal or global over or under coverage (Figure 3). There are a number of indexes that can be used to assist in quantifying acetabular depth and include acetabular

index (also known as acetabular roof angle), femoral head extrusion index and lateral center edge angle of Wiberg.44,45 The acetabular index in the AP X-ray (Figure 3) is determined by making a horizontal line from the most medial point of the sclerotic zone of the acetabulum (line A). Another line is placed from this same point to the lateral edge of acetabulum (line B). When the angle formed by these two lines is equal or less than 0âŹ&#x161; superior focal over coverage of the acetabulum is suggested.46 The femoral head extrusion index (Figure 3) is determined by measuring the distance between a vertical line over the most medial point of the sclerotic zone of the acetabulum and a vertical line over the lateral most edge of the acetabulum. The distance between these two lines in the frontal plane corresponds to line A. Another vertical line is placed from the femoral head-neck junction and the distance between this point and the vertical line over the lateral edge of the acetabulum corresponds to line B. The distance of line B is then divided by the distance of lines A+B and a percentage is created. This index defines the percentage of the femoral head that is without acetabular coverage. Femoral head extrusion index greater than 25% would indicate global undercoverage.19,44 The lateral center edge angle of Wiberg (Figure 3) is created between a vertical line from the center of the femoral head (line A) and a line connecting the

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 260

Figure 3. A) Anteroposterior X-ray of a normal hip; B) Acetabular index–angle formed by a horizontal line (line A) and a line connecting the medial point of the sclerotic zone with the lateral edge of the acetabulum (line B); C) Femoral head extrusion index–line C corresponding to the connection of both extremities of the acetabulum esclerotic zone and line D corresponding to the connection of the femoral head-neck junction and the sclerotic zone of the acetabulum; and D) Lateral center edge angle of Wiberg–a vertical line from the femoral head center (line E) and a line connecting the femoral head center with the lateral edge of the acetabulum (line F).

center of the femoral head with the lateral edge of the acetabulum (line B). The angle formed is normally between 25⬚ and 39⬚. Values less than 25⬚ indicate global acetabular under coverage where values above 39⬚ indicate superior focal over coverage or excessive global acetabular over coverage.24,44-47 As previously noted, excessive acetabular retroversion and anteversion result in focal over coverage in one direction and under coverage in the opposite.

An increased anterior wall characterizes an acetabular retroversion and is detected by the cross-over sign in an AP X-ray of the hip. In those with anatomically normal acetabular anteversion, the edge of the anterior wall (line A) is visualized medially in relation to the posterior wall (line B) (Figure 4). In the case of an acetabular retroversion, the anterior wall is more lateral than the posterior wall and then crosses it medially and noted as a positive cross-over sign (Figure 4).42,44,48 Coxa profunda and protrusio as noted are acetabular deformities that cause global over coverage. Coxa profunda is defined radiographically when the teardropped shaped articular surface of the acetabulum lies medial to the ilioischial line from an anterior-posterior view. Protrusio refers to a medialization of the

femoral head position within the acetabulum.19,49 In the AP image, the line traced over the medial wall of the acetabulum (line A) would normally be visualized laterally to the ilioischial line (line B). When line A touches or surpasses line B, it is classified as a coxa profunda.4 The protrusio index is determined by tracing a line over the medial extremity of the femoral head (line C), which would normally be visualized laterally to the ilioischial line (line B). When the line over the femoral head surpasses the ilioischial line medially, this is classified as acetabular protrusio (Figure 5).4,50 Evidence for interpretation of acetabular deformities Several authors have discussed the validity of these indices, as well as the frequency at which they are found in symptomatic and asymptomatic populations. When those with a surgically identified labral tear were compared to controls, Peelle et al51 found a larger acetabular index (9.6⬚ vs 6.2⬚; p=0.02), but no difference in lateral center edge angle of Wiberg and acetabular retroversion. The Wiberg angle and retroversion may better correlate to the presence of osteoarthritis.52 A Wiberg angle higher than 45⬚, i.e., a deep acetabular socket, was considered a risk factor for hip osteoarthritis.53 Corroborating

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 261

Figure 4. Anterosposterior X-ray of normal hip (A)–anterior wall (line A) being projected more medially than posterior wall (line B); Acetabular retroversion (B)–anterior wall (line C) being more lateral than posterior wall (line D), i.e., showing a crossover sign.

this information, Ezoe et al54 showed that subjects with osteoarthritis were more likely to have acetabular retroversion than are normal subjects. Radiographic acetabular retroversion was present in 20% of patients with hip osteoarthritis compared to 5-7% among the general population.

FEMORAL CONDITIONS Cam quantification The cam type impingement is identified in the cross-table radiographic views and quantified by measuring the alpha angle and anterior offset distance.22,44,55 Figure 6 displays the measurement of

Figure 5. Anterosposterior X-ray–A) The acetabular fossa line (line A) overlapping the ilioischial line medially (line B), indicating a coxa profunda; and B) The femoral head line (line C) touching or overlapping the ilioischial line medially (line D), indicating an acetabulum protusio.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 262

Figure 6. Cross-table X-ray of the right hip (A); Alpha angle (B)–circumference of the femoral head; line A which connects the head center of the femoral neck and line B connecting the head center witht the point of beginning asphericity of the head-neck junction. An angle exceeding 50⬚ is an indicator of an abnormally shaped femoral head-neck junction; Anterior offset (C)–two horizontal lines touching the anterior femoral head (line C) and femoral head-neck junction (line D). The distance between both lines corresponds to the anterior offset (line E).

the alpha angle. The circumference of the femoral head is first outlined. Then, a line is traced (A) from the center of the femoral head towards the central neck region. Another line (B) is traced from the center of the femoral head to the point where the neck ends and the sphericity of the femoral head begins.

The angle formed by the two lines is normally less than 50⬚.4,28,56,57 Values greater than 50⬚ indicate an enlarged anterior-superior femoral head-neck junction. A greater alpha angle has been also identified in those with clinical signs of impingement,58 labral tears,28,51,59 acetabular rim chondral defects, and osteoarthritis28 when compared to asymptomatic controls.

A) and a line drawn along the axis of the femoral neck passing through the femoral head center (line B) (Figure 7).3,60 If a subject exhibits a cervico-diaphyseal angle less than 120⬚, it is classified as coxa vara, whereas an angle greater than 130⬚ is classified as a coxa valga61 Coxa vara is thought to be associated with instability and coxa valga associated with anterior superior labral tears.

The femoral anterior offset distance (Figure 6) is an index that is defined by the distance between the anterior the femoral head and anterior femoral neck.

This distance is measured between a horizontal line at the most superior point of the femoral head (line A) and another horizontal line at the point where the femoral head ends and the neck begins (line B).

The perpendicular distance (line C) between the two lines is the anterior femoral offset distance. An offset less than 10 mm also indicates an enlarged anterior-superior femoral head-neck junction.4,44,57 Cervico-diaphyseal angle The femoral neck is tilted upwards in relation to the diaphysis of the femur at an angle of approximately 125⬚ during adulthood. This cervico-diaphyseal angle can be determined by an AP radiograph. It is the angle formed by the axis of the femoral shaft (line

Figure 7. Cervico-diaphyseal angle–it is the angle formed by the axis of the femoral shaft (line A) and the line a drawn along the axis of the femoral neck passing through the femoral head center (line B).

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 263

Table 1. Physical Exam Findings, Radiographic Findings, and Interpretation in Young Active Individuals with Non-Arthritic Hip Pain

Evidence for Interpretation of Femoral Deformities An alpha angle higher than 50.5ยบ had sensitivity and specificity values of 72% and 100%, respectively, in identifying those with clinical signs of impingement from controls.55 Patients with a clinical exam consistent with FAI showed a significant reduction in head-neck offset in the lateral and anterior aspect of the femoral neck.62 However it is important to highlight that this study used an MRI-assessment.

INTEGRATION OF CLINICAL AND RADIOGRAPHIC ASSESSMENT It is important to highlight the necessity of using radiographs in conjunction with physical exam finding because the imaging findings are not always related to the presence of pain, and vice-versa. A summary relating the sign, radiographic measures

and interpretation can be found in Table 1. Related to acetabular conditions, a recent study conducted

by Kang et al63 evaluated 100 hips in asymptomatic population and found an increased Wiberg angle in 16%, acetabular retroversion in 14%, and positive cross-over sign in 20% of subjects. Moreover, Tannast et al4 evaluated the cross-over sign in 55 patients with FAI and it was present in only 53% of hips. Although, the cross-over sign had a sensitivity of 71% and specificity of 88% for hip impingement, the authors noted that this sign by itself was not enough to diagnose FAI. Similarly, femoral changes found in radiological analysis are not sufficient to ensure the presence of pain or functional deficits.

Kang et al63 also found an increased alpha angle in 10% of the hips and changes in the femoral head sphericity in 74% of asymptomatic population. In clinical terms, the bone abnormalities may provoke

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 264

pain by causing repetitive microtrauma in the hip joint, especially in subjects with abnormal movement patterns of lower limbs during physical activity of functional tasks.4,21,61,64-66 Clinicians should be aware of the large number of false positive findings associated with the radiographic measures discussed in the paper. This exemplifies the notion that radiographic findings must be used in conjunction with history and clinical examination in order to be properly interpreted.

CONCLUSION History and physical examination can be useful to classify young active individuals with non-arthritic intra-articular hip pathology as having impingement or instability. However, the specific type of deformity leading to symptoms may not be apparent from this evaluation. Several radiological indexes have been described in the literature for individuals with non-arthritic hip pathology. The paper outlines the clinical indications, methods, and interpretation of hip radiological images as it relates to physical examination findings for those with non-arthritic hip pathology.

REFERENCES 1. Martin RL, Sekiya JK. The interrater reliability of 4 clinical tests used to assess individuals with musculoskeletal hip pain. J Orthop Sports Phys Ther.

2008;38(2):71-7.

2. Pfirrmann CWA, Mengiardi B, Dora C, Kalberer F, Zanetti M, Hodler J. Cam and pincer femoroacetabular impingement: characteristic MR arthrographic findings in 50 patients. Radiology.

2006: 240(3): 778-85.

3. Robertson DD, Britton CA, Latona CR, Armfield DR, Walker PS, Maloney WJ. Hip Biomechanics: Importance to Functional Imaging. Semin Musculoskelet Radiol. 2003;7(1):27-41.

4. Tannast M, Siebenrock KA, Anderson SE. Femoroacetabular Impingement: radiographic diagnosis - what the radiologist should know. AJR. 2007;188:1540–52.

5. Kivlan BR, Martin RL. Classification-based treatment of hip pathology in older adults. Topics Ger Rehab.

29:218-226; 2013.

6. Martin RL, Enseki KR: Nonoperative Management and Rehabilitation of the Hip. In: Sekiya JK, Safran M, Ranawat A, Leunig M, eds. Techniques in Hip Arthroscopy and Joint Preservation Surgery.

Philadelphia PA: Elsevier; 67-73; 2010.

7. Goodman CC, Snyder TEK, Differential Diagnosis for Physical Therapists. Screeing fro Referral. 4th ed. 2007, Philadelphia, PA: Saubders Elsevier.

8. Brown MD, Gomez-Marin O, Brookfield KF, Li PS. Differential diagnosis of hip disease versus spine disease. Clin Orthop Relat Res. 2004;(419)(419):280-284.

9. Fritz JM, Cleland JA, Childs JD. Subgrouping patients with low back pain: Evolution of a classification approach to physical therapy. J Orthop Sports Phys Ther. 2007;37(6):290-302.

10. Laslett M, Young SB, Aprill CN, McDonald B. Diagnosing painful sacroiliac joints: A validity study of a McKenzie evaluation and sacroiliac provocation tests. Aust J Physiother. 2003;49(2):89-97.

11. Maher C, Adams R. Reliability of pain and stiffness assessments in clinical manual lumbar spine examination. Phys Ther. 1994;74(9):801-9; discussion 809-11.

12. Sugioka T, Hayashino Y, Konno S, Kikuchi S, Fukuhara S. Predictive value of self-reported patient information for the identification of lumbar spinal stenosis. Fam Pract. 2008;25(4):237-244. doi: 10.1093/ fampra/cmn031.

13. Leunig M, Werlen S, Ungersbock A, Ito K, Ganz R. Evaluation of the acetabular labrum by MR arthrography. J Bone Joint Surg Br. 1997;79:230-4.

14. Maslowski E, Sullivan W, Forster Harwood J, et al.

The diagnostic validity of hip provocation maneuvers to detect intra-articular hip pathology.

PM & R J Injury, function, and rehabilitation.

2010;2:174-81.

15. Sutlive TG, Lopez HP, Schnitker DE, et al.

Development of a clinical prediction rule for diagnosing hip osteoarthritis in individuals with unilateral hip pain. J Orthop Sports Phys Ther.

2008;38:542-50.

16. Cacchio A, Borra F, Severini G, Foglia A, Musarra F, Taddio N, De Paulis F. Reliability and validity of three pain provocation tests used for the diagnosis of chronic proximal hamstring tendinopathy. Br J Sports Med. 2012;46(12):883-7.

17. Martin HD. Clinical examination of the hip. Oper Tech Orthop. 2005;15:177-81.

18. Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res. 2003;417:112-20.

19. Ganz R, Leunig M, Leunig-Ganz K, Harris WH. The etiology of osteoarthritis of the hip: an integrated mechanical concept. Clin Orthop Relat Res. 2008;466:264-72.

20. Anderson LA, Peters CL, Park BB, Stoddard GJ, Erickson JA, Crim JR. Acetabular cartilage

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 265

21.

22.

23.

24.

delamination in femoroacetabular impingement.

Risk factors and magnetic resonance imaging diagnosis. J Bone Joint Surg Am. 2009;91:305-13.

Klingenstein GG, Martin R, Kivlan B, Kelly BT. Hip injuries in the overhead athlete. Clin Orthop Relat Res. 2012;470:1579-85.

Beck M, Kalhor M, Leunig M, Ganz R. Hip morphology influences the pattern of damage to the acetabular cartilage: femoroacetabular impingement as a cause of early osteoarthritis of the hip. J Bone Joint Surg Br. 2005;87(7):1012-8.

Beck M, Leunig M, Parvizi J, Boutier V, Wyss D, Ganz R. Anterior femoroacetabular impingement: part II. Midterm results of surgical treatment. Clin Orthop Relat Res. 2004;418:67-73.

Tonnis D, Heinecke A. Acetabular and femoral anteversion: relationship with osteoarthritis of the hip. J Bone Joint Surg Am. 1999;81:1747-70

25. Anderson SE, Siebenrock KA, Tannast M. Femoroacetabular impingement. Eur J Radiol.

2012;81(12):3740-4.

26. Banerjee P, Mclean CR. Femoroacetabular impingement: a review of diagnosis and management. Curr Rev Musculoskelet Med. 2011;4:2332.

27. Clohisy JC, Knaus ER, Hunt DM, Lesher JM, HarrisHayes M, Prather H. Clinical presentation of patients with symptomatic anterior hip impingement. Clin Orthop Relat Res. 2009;467:638-44.

28. Johnston TL, Schenker ML, Briggs KK, Philippon MJ. Relationship between offset angle alpha and hip chondral injury in femoroacetabular impingement.

Arthroscopy. 2008;24:669-75.

29. Philippon MJ, Maxwell RB, Johnston TL, Schenker M, Briggs KK. Clinical presentation of femoroacetabular impingement. Knee Surg Sports Traumatol Arthrosc. 2007; 15(7):908-14.

30. Martin HD, Shears SA, Palmer IJ. Evaluation of the hip. Sports Med Arthrosc. 2010;18:63-75.

31. Souza RB, Powers CM. Concurrent criterion-related validity and reliability of a clinical test to measure femoral anteversion. J Orthop Sports Phys Ther.

2009;39(8):586-92.

32. Boykin RE, Anz AW, Bushnell BD, Kocher MS, Stubbs AJ, Philippon MJ. Hip instability. J Am Acad Orth Surg. 2011;19:340-9.

33. Martin RL, Enseki KR, Draovitch P, Trapuzzano T, Philippon MJ. Acetabular labral tears of the hip: Examination and diagnostic challenges. J Orthop Sports Phys Ther. 2006;36:503-15.

34. Philippon MJ. The role of arthroscopic thermal capsulorrhaphy in the hip. Clin Sports Med. 2001;20:817-29.

35. Schenker ML, Weiland DE, Philippon MJ. Current Ttrends in Hip Arthroscopy: A review of injury Diagnosis, Techniques and Outcome Scoring. Current Opnion in Orthopaedics. 2005;16:89-94.

36. Li H, Mao Y, Oni JK, Dai K, Zhu Z. Total hip replacement for developmental dysplasia of the hip with more than 30% lateral uncoverage of uncemented acetabular components. Bone Joint J. 2013;95(9):1178-83.

37. Smith CD, Masouros S, Hill AM, Amis AA, Bull AM. A biomechanical basis for tears of the human acetabular labrum. Br J Sports Med. 2009;43:574-8.

38. Martin RL, Palmer I, Martin HD. Ligamentum teres: a functional description and potential clinical relevance. Knee Surg Sports Traumatol Arthrosc.

2012;20:1209-14.

39. Mitchell B, McCrory P, Brukner P, O’Donnell J, Colson E, Howells R. Hip joint pathology: clinical presentation and correlation between magnetic resonance arthrography, ultrasound, and arthroscopic findings in 25 consecutive cases. Clin J Sports Med. 2003;13:152-6.

40. Neumann DA. Cinesiologia do aparelho musculoesquelético. Fundamentos para reabilitação física. 1st ed. 2006, Rio de Janeiro, RJ: Guanabara Koogan.

41. Beighton P, Solomon L, Soskolne CL. Articular mobility in an African population. Ann Rheum Dis. 1973;32:413-8.

42. Siebenrock KA, Kalbermatten DF, Ganz R. Effect of pelvic inclination on determination of acetabular retroversion: a study on cadaver pelvis. Clin Orthop Relat Res. 2003;407:241–8.

43. Polesello GC, Nakao TS, Queiroz MC, et al. Proposal for standardization of radiographic studies on the hip and pelvis. Rev Bras Ortop. 2011;46(6):634-42.

44. Armfield DR, Towers JD, Robertson DD. Radiographic and MR imaging of the athletic hip.

Clin Sports Med. 2006;25:211–39.

45. Wiberg, G. Studies on Dysplastic Acetabula and Congenital Subluxation of the Hip Joint. Acta Chirurgica Scandinavica. 1939;83, Supplementum 58.

46. Murphy SB, Kijewski PK, Millis MB, Harless A. Acetabular dysplasia in the adolescent and young adult. Clin Orthop Relat Res. 1990;261:214–23.

47. Philippon MJ, Wolff AB, Briggs KK, Zehms CT, Kuppersmith DA. Acetabular rim reduction for the treatment of femoroacetabular impingement correlates with preoperative and postoperative center-edge angle. Arthroscopy. 2010;26(6):757-61.

48. Reynolds D, Lucac J, Klaue K. Retroversion of the acetabulum: a cause of hip pain. J Bone Joint Surg Br. 1999;81:281–8.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 266

49. Samora JB, Ng VY, Ellis TJ. Femoroacetabular Impingement: A Common Cause of Hip Pain in Young Adults. Clin J. Sport med. 2011;21(1):51-6.

50. Sotelo-Garza A, Charnley J. The Results of Charnley Arthroplasty of the Hip Performed for Protrusio Acetabuli. Clin Orthop. 1978;132:12-8.

51. Ecker TM, Tannast M, Puls M, Siebenrock KA, Murphy SB. Pathomorphologic alterations predict presence or absence of hip osteoarthrosis. Clin Orthop Relat Res. 2007;465:46-52.

52. Gosvig KK, Jacobsen S, Sonne-Holm S, Palm H. Troelsen A. Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey.

J Bone Joint Surg Am. 2010;92:1162-9.

53. Ezoe M, Naito M, Inoue T. The prevalence of acetabular retroversion among various disorders of the hip. J Bone Joint Surg Am. 2006;88:372-9.

54. Meyer DC, Beck M, Ellis T, Ganz R, Leunig M. Comparison of six radiographic projections to assess femoral head/neck asphericity. Clin Orthop.

2006;445:181-5.

55. Hack K, Di Primo G, Rakhra K, Beaule PE. Prevalence of cam-type femoroacetabular impingement morphology in asymptomatic volunteers. J Bone Joint Surg Am. 2010;92:436-44.

56. Pollard TCB, Villar RN, Norton MR, Fern ED, Williams MR, Simpson DJ, et al. Femoroacetabular impingement and classification of the cam deformity: the reference interval in normal hips.

Acta Orthop. 2010;81(1):134–41.

57. Clohisy JC, Nunley RM, Otto RJ, Schoenecker PL. The frog-leg lateral radiograph accurately visualized hip cam impingement abnormalities. Clin Orthop Relat Res. 2007;462:115-21.

58. Peele MW, Della Rocca GJ, Maloney WJ, Curry MC, Clohisy JC. Acetabular and femoral radiographic abnormalities associated with labral tears. Clin Orthop Relat Res. 2005;441:327-33.

59. Narvani AA, Tsiridis E, Kendall S, Chaudhuri R, Thomas P. A preliminary report on prevalence of acetabular labrum tears in sports patients with groin pain. Knee Surg Sports Traumatol Arthrosc.

2003;11:403-8.

60. Millis MB, Kim YJ, Kocher MS. Hip joint-preserving surgery for the mature hip: the Children’s Hospital experience. Orthop J Harv Med S. 2004;6:84–7 61. Polkowski GG, Clohisy JC. Hip Biomechanics. Sports Med Arthrosc Rev. 2010;18(2):56–62.

62. Ito K, Minka MA, Leunig M, Werlen S, Ganz R. Femoroacetabular impingement and the cam-effect.

A MRI-based quantitative anatomical study of the femoral head-neck offset. J Bone Joint Surg Br. 2001;83:171-6.

63. Kang ACL, Gooding AJ, Coates MH, Goh TD, Armour P, Rietveld J. Computed tomography assessment of hip joints in asymptomatic individuals in relation fo femoroacetabular impingement. Am J Sports Med. 2010,38(6):1160-5.

64. Austin AB, Souza RB, Meyer JL, Powers CM. Identification of abnormal hip motion associated with acetabular labral pathology. J Orthop Sports Phys Ther. 2008;38(9):558-65.

65. Emara K, Samir W, Motasem H, Ghafar KA. Conservative treatment for mild femoroacetabular impingement. J Orthop Surg. 2011;19(1):41-5.

66. Yazbek, PM, Ovanessian, V, Martin, RL, Fukuda, TY. Nonsurgical treatment of acetabular labrum tears: a case series. J Orthop Sports Phys Ther. 2011:41(5):34656.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 267

IJSPT

CLINICAL COMMENTARY

ACL RECONSTRUCTION ď&#x161;ş ITâ&#x20AC;&#x2122;S ALL ABOUT TIMING Stephanie Evans, PT, DPT1 Justin Shaginaw, MPT, ATC2 Arthur Bartolozzi, MD2

ABSTRACT Injury to the anterior cruciate ligament (ACL) is the most common ligamentous injury, ranging from up to 200,000 injuries per year in the United States. Sports such as soccer, football, and skiing have been reported to be high-risk sports that can cause injury to the ACL when compared to other sport activities. Due to the high incidence of ACL injuries, approximately 100,000 ACL reconstructions are performed each year.

Although conservative treatment can potentially be successful in the appropriate population, patients with goals of returning to high levels of sport activity may not be successful with conservative treatment. Even though reconstruction is the most common treatment for ACL rupture, there remains debate in the literature regarding the optimal timing of surgery. Therefore, the purpose of this clinical commentary is to review the available evidence to provide insight into the optimal timing of ACL reconstruction.

Keywords: Anterior cruciate ligament, arthrofibrosis, reconstruction, timing

CORRESPONDING AUTHOR 1

Aria Health Department of Physical Therapy, Fairless Hills, PA, USA 2 Aria 3B Orthopaedic Institute, Philadelphia, PA, USA The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 268

INTRODUCTION Injury to the anterior cruciate ligament (ACL) is the most common ligamentous injury, ranging up to 200,000 injuries per year in the United States.1 Sports such as soccer, football, and skiing have been reported to be high-risk sports and individuals who participate in these sports are 10 times more likely to rupture the ACL when compared to other sport activities.2 Additionally, women who participate in intercollegiate soccer, basketball, and rugby are approximately four times more likely than males (who participate in those same sports) to rupture their ACL.3 The mechanism of injury to the ACL is associated with neuromuscular and biomechanical abnormalities, including large frontal and transverse plane movements of the knee, mutations within collagen producing genes, hormonal factors related to the female menstrual cycle, and primary anatomical and structural influences.4 For example, motions that occur with cutting and pivoting, such as varus/ valgus and internal/external rotation movements at the knee, can result in rupture of the ACL.5 Due to the high incidence of ACL injuries, approximately 100,000 ACL reconstructions are performed each year.6 Although conservative treatment can potentially be successful in the appropriate population, patients with goals of returning to high levels of sport activity are typically not successful with conservative treatment.7 Even though reconstruction is the most common treatment for ACL rupture, there remains debate in the literature regarding the optimal timing of surgery.8 Smith et al9 concluded from their systematic review that there were no differences in clinical outcomes between early (less than 3 weeks) and delayed (greater than 6 weeks) ACL reconstruction (ACLR); however, their conclusion is based on present literature that has limitations, such as non-randomization and lack of appropriate blinding.9 From a patient perspective, high level athletes frequently request surgery as soon as possible in order to return to play whereas individuals who are not involved with physically demanding activities may delay surgery due to personal or societal obligations. In both instances, adverse complications, which will be discussed throughout this clinical commentary, can negatively affect patient outcomes.

Healthcare providers, including physical therapists,

must be knowledgeable regarding the risks of early and delayed surgical intervention in order to educate patients appropriately; therefore, the purpose of this clinical commentary is to review the available evidence in order to provide insight into the optimal timing of ACLR. REVIEW OF EXISTING EVIDENCE Shelbourne and colleagues10 retrospectively studied 169 acute ACL reconstructions and evaluated the effect of timing of surgery and accelerated rehabilitation on patient outcomes. Patients who had undergone reconstruction within the first week of injury had a significant increase in arthrofibrosis compared to those who had surgery greater than 21 days from injury.10 Interestingly, patients who underwent reconstruction between 8 and 21 days from injury and underwent an accelerated rehabilitation program had a decreased incidence of arthrofibrosis as compared to those who underwent a conventional rehabilitation program. However, the results of this study are now greater than 20 years old and there have been multiple advancements in the acute management and surgical technique associated with ACLR, thus the results must be interpreted cautiously. Shelbourne and Patel11 reviewed the perioperative factors that are important to consider prior to surgery. The authors concluded that mental preparation, scheduling, associated knee joint pathology and preoperative knee condition (i.e. minimal to no swelling, adequate strength, and full range of motion) should be carefully assessed to determine timing of reconstruction.

Furthermore, Almekinders and colleagues12 studied 70 adults who underwent ACLR using a bone-patella tendon-bone autograft. Patients who underwent reconstruction less than one month from injury had limitations in knee range of motion early in rehabilitation; however, after one year, there were no differences in motion between patients who underwent early or delayed surgery. Passler et al13 assessed complications associated with timing of surgical intervention in 283 patients. Approximately 18% of individuals that had surgery within 7 days of injury developed arthrofibrosis, compared to only 6% of patients who waited at least 4 weeks.13 However, Bottoni and colleagues8 found no differences in knee

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 269

range of motion (ROM) between patients who underwent early reconstruction versus those who waited at least 6 weeks. But, the patients who participated in the study were active military personnel and may not be representative of the general population, thus generalization is limited.

Mayr et al14 studied the effect of timing as well as preoperative knee status on ACLR outcomes. The authors documented the irritability of the knee before surgery (i.e. swelling, effusion, hyperthermia), ROM, and additional injuries. The authors reported a correlation between reconstruction within the first 4 weeks of injury and the development of arthrofibrosis. However, the authors also found a strong association between preoperative irritation of the knee and arthrofibrosis. Interestingly, those who underwent surgery after 4 weeks with an irritated knee had a similar chance of developing arthrofibrosis as those who underwent an earlier reconstruction. Preoperative deficits in knee extension and knee flexion ROM were also predictive of postoperative arthrofibrosis. The results of this study indicate that the status of the knee prior to surgery may be a more important factor than injury-to-surgery interval in determining optimal timing of reconstruction.14 Conversely, delayed ACLR is another topic of interest when investigating optimal timing of ACLR. Operational definitions for delayed versus early ACLR may

vary between authors, thus careful analysis and interpretation of results is critical. For example, Frobell et al15 defined early reconstruction as being performed within 10 weeks after injury. The authors did not specifically define delayed reconstruction; however, in their study, delayed reconstruction was performed between 5.5 and 19 months following randomization.

Alternatively, Meighan et al16 defined early as surgery occurring within 2 weeks and delayed as occurring within 8-12 weeks (Table 1).

Patients with ACL-deficient knee often have chronic rotational and translation instability that can cause giving way episodes as well as further knee damage including meniscal tears, osteochondral defects, and ligament tears.17 Church and Keating18 reviewed 183 patients who had undergone ACLR to analyze the incidence of meniscal tears and degenerative change in relation to the timing of surgery after injury.18 Their results showed that there was a significant increase in meniscal tears in those individuals who had undergone surgery greater than 1 year after injury. Using the French Society of Arthroscopy (SFA) system, a higher incidence of knee degeneration was found in those who waited more than 12 months to have surgery.18 Kennedy et al19 found similar results regarding the relationship between timing of ACLR and prevalence of meniscal and chondral defects. Athletes

Table 1. Operational definitions of early versus delayed ACL

Study

“Early” ACLR Definition

Frobell et al15

Within 10 weeks after injury

Meighan et al16 Church and Keating18 Kennedy et al19

Within 2 weeks Within 12 months Offered no specific definition

Bottoni et al8

Early possible date from injury Within a mean of 3 weeks post-injury

Smith et al9

“Delayed” ACLR Definition Offered no specific definition; however, delayedwas performed between 5.5 and 19 months after randomization Within 8-12 weeks After 12 months Offered no specific definition; divided patients into groups A (0-2 months), B (2-6 months), C (6-12 months), D (12-18 months), E (greater than 19 months) A minimum of 6 weeks from injury A minimum of 6 weeks from date of injury

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 270

who had undergone reconstruction at least one year after their initial injury had a significantly higher incidence of medial meniscus tears. However, there was no association between lateral meniscus pathology and timing of surgery. The authors also found a higher occurrence of degenerative changes in those who had surgery six months after injury. Ă&#x2026;hlĂŠn and colleagues20 found that patients who underwent reconstruction within 5 months of injury had better outcomes on the Lysholm Knee Questionnaire and Tegner Activity scale as compared to patients who waited at least 24 months to have surgery. There was no statistically significant difference in the incidence of meniscal tears between groups; however, the authors state that this may be due to a Type 2 error that occurred due to low sample size.

Granan et al21 organized a large cohort study which prospectively collected information regarding all cases of ACLR in Norway. The authors analyzed 3699 patients who underwent primary ACLR in order to determine the association between timing of surgical intervention and the risk of developing additional pathology.21 The authors did not find an association between the development of articular cartilage or meniscal pathology in children (16 years or younger). However, in young adults (17-40 years) and older adults (41 years and older), for each month that passed from initial injury to surgery, the odds ratio for an articular cartilage lesion increased by approximately 1%. Anstey and colleagues22 found the prevalence of new medial meniscus tears in individuals who underwent surgery less than 6 months and more than 6 months to be 4.1% and 16.7%, respectively.

DISCUSSION The optimal timing of ACLR is an important clinical decision that affects patient outcomes significantly.

Even though there is no consensus in the literature, there are some trends regarding timing of ACLR. Various authors suggest that ACLR be performed at least 3 weeks after injury in order to avoid arthrofibrosis.10,11,12,13 More important than time alone, objective criteria including perioperative swelling, edema, hyperthermia, and ROM are important indicators of when surgery should be performed.14 Preoperative quadriceps strength has also been suggested to

influence outcomes following ACLR. Eitzen et al23 found that patients with quadriceps strength deficits greater than 20% prior to surgery had significantly greater deficits in strength two years following surgical intervention. Thus, these authors suggest that surgery be performed only when involved quadriceps muscle strength is 80% of the uninvolved lower extremity.

Timing of surgical intervention may only be one factor that should be considered when determining optimal timing of surgery. The decision of when to undergo ACLR is likely multifactorial and may include factors such as pre-operative status of the knee, family, school or work obligations, as well as mental preparation. More research is needed in order to identify a multifactorial objective algorithm that could be used to assist the surgeon and patient in determining when surgical interventions should occur in order to yield optimal clinical results.

Throughout the literature, there appears to be a lack of consensus regarding the operational definitions of early versus delayed ACLR (Table 1). Of the studies included in this clinical commentary, no two studies used the same definition of early versus delayed.

Church and Keating18 used 12 months as a marker to distinguish between early versus delayed. Bottoni et al8 defined early reconstruction as occurring at the earliest possible date from injury and delayed reconstruction as a minimum of 6 weeks from the date of injury. Due to the considerable variation in injury-to-surgery interval, it appears that a third definition of acute ACLR may be helpful in order to clearly delineate timeframes. More precise operational definitions of acute, early, and delayed may allow for better control and generalization of results across the literature.

Post-operative rehabilitation has changed substantially as improved surgical techniques have evolved.

In a recent clinical commentary, the authors advocated for an objective based rehabilitation program that focuses on meeting specific clinical milestones prior to progressing to the next stage of rehabilitation.24 Current surgical techniques allow for accelerated rehabilitation with emphasis on early mobilization, weight bearing, and lower extremity strength training following isolated ACLR.25 With advanced surgi-

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 271

cal techniques and accelerated rehabilitation, further research is needed to determine the effects of acute inflammation of the knee on the reconstructed ACL and other intra-articular structures, which may affect long-term post-operative outcomes. The option of surgical intervention within days of injury may appeal to professional athletes or other individuals who must return to their prior level of functional as soon as possible. Conversely, the option of delayed surgical intervention may appeal to others who have less rigid time constraints or may desire to prepare to a greater degree pre-operatively.

CONCLUSIONS There are significant potential complications associated with both early and delayed surgical reconstruction of the ACL, which can negatively affect clinical outcomes. The careful consideration of these complications is paramount when healthcare professionals, including both the physical therapist and surgeon, educate patients on the optimal timing of ACLR. As such, physical therapists should be diligent in regularly reviewing the literature in order to ensure that as new evidence emerges, accurate and effective education can be given to all patients considering ACLR. REFERENCES 1. Centers for Disease Control & Prevention, National Center for Health Statistics. National hospital discharge survey: annual summary. 1996 [monograph on the Internet]. Atlanta, GA: Centers for Disease Control and Prevention. 1996.

2. Dragoo JL, Bruan HJ, Durham JL, Chen MR, Harris AHS. Incidence and risk factors for injuries to the anterior cruciate ligament in National Collegiate Athletic Association football: data from 2004-2005 through 2008-2009 national collegiate athletic association injury surveillance system. Am J Sports Med. 2012; 40 (5): 990- 995.

3. Gwinn DE, Wilckens JH, McDevitt ER, Ross G, Koa TC. The relative incidence of anterior cruciate ligament injury in men and women at the United States Naval Academy. Am J Sports Med. 2000; 28:98– 102 4. Shultz SJ, Schmitz RJ, Benjaminse A, Chaudhari AM, Collins M, Padau DA. ACL research retreat VI: an updated on ACL injury risk and prevention. J Athl Train. 2012; 47(5): 591-603.

5. Siegel L, Vandenakker-Albanese C, Siegel D. Anterior cruciate ligament injuries: anatomy, physiology, biomechanics, and management. Clin J Sport Med. 2012; 22 (4): 349-355.

6. Hughes G & Watkins J. A risk-factor model for anterior cruciate ligament injury. Sports Med. 2006; 36: 411-428.

7. Wittenberg RH, Oxfort HU, Plafki C. A comparison of conservative and delayed surgical treatment of anterior cruciate ligament ruptures: a matched pair analysis. Int Orthop. 1998; 22:145–148.

8. Bottoni CR, Liddell TR, Trainor TJ, Freccero DM, Lindell KK. Postoperative range of motion following anterior cruciate ligament reconstruction using autograft hamstrings. A Prospective, Randomized Clinical Trial of Early Versus Delayed Reconstructions.

Am J Sports Med. 2008; (36)4: 656-662.

9. Smith TO, Davies L, Hing CB. Early versus delayed surgery for anterior cruciate ligament reconstruction: a systematic review and metaanalysis. Knee Surg Sports Traumatol Arthrosc. 2010; 18: 304-311.

10. Shelbourne KD, Wilcken JH, Mollabashy A, DeCarlo M . Arthrofibrosis in acute anterior cruciate ligament reconstruction. The effect of timing of reconstruction and rehabilitation. Am J Sports Med. 1991; 19(4): 332-226.

11. Shelbourne KD & Patel DV. Timing of surgery in anterior cruciate ligament-injured knees. Knee Surg Sports Traumatol Arthrosc. 1995; 3(3): 148-156.

12. Almekinders LC, Moore T, Freedman D, Taft TN. Post-operative problems following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 1995; 3(2): 78-82.

13. Passler JM, Schippinger G, Schweighofer F, Fellinger M, Seibert FJ. Complications in 283 cruciate ligament replacement operations with free patellar tendon transplantation. Modification by surgical technique and surgery timing. Unfallchirurgie. 1995; 21(5): 240-246.

14. Mayr HO, Weig TG, Plitz W. Arthrofibrosis following ACL reconstruction- reasons and outcomes. Arch Orthop Trauma Surg. 2004; 124: 518-522.

15. Frobell RB, Roos EM, Roos HP, Ranstam J, Lohmander LS. A randomized trial of treatment for acute anterior cruciate ligament tears. New Engl J Med. 2010; 363(4): 331- 342.

16. Meighan AAS, Keating JF, Will E. Outcome after reconstruction ligament in athletic patients: a comparison of early versus delayed surgery. J Bone Joint Surg. 2003; 85-B(4): 521-524.

17. Demirag B, Aydemir F, Danis M, Ermutlu C. Incidence of meniscal and osteochondral lesions in

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 272

18.

19.

20.

21.

patients undergoing delayed anterior cruciate ligament reconstruction. Acta Orthop Traumatol Turc.

2011; 45(5): 348-352.

Church S & Keating JF. Reconstruction of anterior cruciate ligament: timing of surgery and the incidence of meniscal tear and degenerative change.

J Bone Joint Surg. 2005; 87(12): 1639-1642.

Kennedy J, Jackson MP, O’Kelly P, Moran R. Timing of reconstruction of the anterior cruciate ligament in athletes and the incidence of secondary pathology within the knee. J Bone Joint Surg. 2010; 92(3): 362-366. Åhlén M & Lidén M. A comparison of the clinical outcome after anterior cruciate ligament reconstruction using a hamstring tendon autograft with special emphasis on the timing of the reconstruction. Knee Surg Sports Traumatol Arthrosc.

2011; 19: 488-494.

Granan LP, Bahr R, Lie SA, Engebretsen L. Timing of anterior cruciate ligament reconstructive surgery

22.

23.

24.

25.

and risk of cartilage lesions and meniscal tears. Am J Sports Med. 2009; 37(5): 955-961.

Anstey DE, Heyworth BE, Price MD, Gill TJ. Effect of timing of ACL reconstruction in surgery and development of meniscal and chondral lesions. Phys Sportsmed. 2012; 40(1): 36-40.

Eitzen I, Holm I, Risberg MA. Preoperative quadriceps strength is a significant predictor of knee function two years after anterior cruciate ligament reconstruction. Br J Sports Med. 2009; 43(5):371-376.

Adams D, Logerstedt D, Hunter-Giordano A, Axe MJ, Snyder-Mackler L. Current concepts for anterior cruciate ligament reconstruction: a criterion-based rehabilitation program. J Orthop Sports Phys Ther.

2012; 42(7):601-14.

Harvey A, Thomas NP, Amis AA. Fixation of the graft in reconstruction of the anterior cruciate ligament. J Bone Joint Surg Br. 2005: 87(5):593-603.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 273

IJSPT

CLINICAL COMMENTARY

CURRENT CONCEPTS OF ROTATOR CUFF TENDINOPATHY David Factor, DPT, EMT-P1 Barry Dale, PT, PhD, DPT, ATC, SCS, OCS, CSCS2

ABSTRACT Purpose/Background: Tendinopathies are a broad topic that can be examined from the lab to their impact upon function. Improved understanding will serve to bring this pathology to the forefront of discussion, whether in the clinic or the classroom. The purpose of this current concepts clinical commentary is to explore intrinsic and extrinsic mechanisms of rotator cuff (RC) tendinopathy in order to improve clinical and research understanding.

Methods: Pubmed, Medline, Cinahl, PEDro, and Cochrane databases were searched, limiting results to those published in the English language, between the years of 2005 and 2012. The key search terms utilized were intrinsic mechanisms, tendinopathy, stem cells, biologics, platelet-rich plasma (PRP), healing, rotator cuff tears, full-thickness tears, tests, impingement, imaging, ultrasound, Magnetic Resonance Imaging (MRI), radiograph, shoulder advances, treatment, diagnoses, tendon disorders, pathogenesis, matrix metalloproteinase, injections, and RC repair. Over 150 abstracts were reviewed and 43 articles were analyzed for quality and relevance using the University of Alberta Evidence Based Medicine Toolkit.

Results/Conclusions: Current evidence suggests that tendinopathies arise from a multivariate etiology.It is increasingly evident that intrinsic mechanisms play a greater role than extrinsic mechanisms in this process. Emphasis should be placed on patient information (i.e. background information and personal description of symptoms) and imaging/ injection techniques in order to aid in diagnosis. Future treatment technologies such as cell therapy and biological engineering offer the hope of improving patient outcomes and quality of life.

Level of Evidence: Level 5 â&#x20AC;&#x201C; Clinical Commentary Related to a Review of Literature Key Words: Rotator cuff, tendinopathy, tendinitis, tendinosis

1 2

Saint Louis, MO, USA University of Tennessee â&#x20AC;&#x201C; Chattanooga, Chattanooga, TN, USA

This project did not involve human subjects, and therefore did not require Institutional Review Board approval.

CORRESPONDING AUTHOR David Factor, DPT, EMT-P Saint Louis, Missouri, United States of America 4953 Kerth Road, Saint Louis, Missouri E-mail: dfact@hotmail.com

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 274

INTRODUCTION Shoulder pain is the third most common musculoskeletal complaint.1 Some commonly diagnosed shoulder problems include impingement of the rotator cuff tendons or subdeltoid bursa, bicipital tendonitis, frozen shoulder, and glenohumeral (GH), and acromioclavicular (AC) arthritis.2 With the unknown incidence of partial rotator cuff tears (PRCTs), defined as tears involving less than 50% of the muscle, the clinician needs to fully understand the condition in order to best address the patientâ&#x20AC;&#x2122;s problem.2 Authors have shown that full thickness tears are usually due to chronic degeneration.3,4 Furthermore, most rotator cuff pathologies can be treated with reasonable success using conservative therapy despite the lack of high quality evidence.2 If a diagnosis of tendinopathy has been made, it is important to take the diagnosis a step further and decipher whether the tendinopathy is from extrinsic causes, intrinsic causes, or a combination of the two.

When a patient partially tears their rotator cuff (RC), it is common that they present with reduced shoulder function (i.e. dyskinesis, weakness, pain, and stiffness).2 They may also have pain at rest, night pain, or a painful arc.2 Upon evaluation, the clinician may find weak external rotators, a weak supraspinatus, and signs of impingement.2 Signs of impingement may include painful overhead reaching, an inflamed subdeltoid bursa, or positive special tests meant to provoke symptoms. In patients over the age of 60 with two out of three of the aforementioned symptoms (i.e. weak external rotators, weak supraspinatus, impingement signs previously listed), there is a 98% chance of a RC tear.5 Patients can also present with pain radiating to the lateral mid-humerus or anterolateral acromion, pain while lying on the shoulder or sleeping with the arm overhead, and pain that occurs when reaching above the head.6 In addition, Fukuda observed that PRCTs are more painful than full thickness tears.7 Factors taken into account when considering surgery include the patientâ&#x20AC;&#x2122;s functional needs, age, health, size of the tear, and amount of fatty infiltration into the muscle.2,8,9 It is estimated that 75,000 RC surgical repairs are performed in the United States each year.10 Age plays a factor as it is unusual for young patients to have RC tears requiring surgery.11 If a young patient presents with acute, post-traumatic

weakness without any pre-existing RC problem, then it is generally accepted as an absolute indication for surgery.2 In terms of tear size, if the RC tendons are greater than 50% torn, then surgery is commonly recommended.2 Pre-operative rotator cuff tear size is the main factor in determining long-term outcome of repair in relation to range of motion (ROM), strength, and need for another surgery.12 Chronic tears are less likely to heal with surgery than acute tears.13 Surgery on chronic RC injuries has a wide ranging failure rate (30-94%) even with the use of newer techniques (e.g., double-row repairs), which could point to other variables for surgical failure such as aging, tendon to bone failure, and degeneration.14-21 Poor muscle quality, delamination of tendons, and longer postoperative follow-up, are all related to lower healing rates and inferior results.22,23 Even if the structural status of the repair is not ideal, the patientâ&#x20AC;&#x2122;s symptoms after surgery can still improve.14,24 In addition, better outcomes are associated with proper healing of the greater tuberosity and an intact repair,14,24 and acromioplasty appears to play a role in successful outcomes after surgery for reducing impingement.25-27 Physical therapy can also play a role in the success after a RC surgery, but often varies widely between therapists and typically orthopedic surgeons do not choose their therapist.28 Physical therapists may consider mechanisms involved in the genesis of tendon injury, but the treatment of both tendinopathy and subsequent RC repair is based on the impairments.29 Research supports strengthening the scapular stabilizers and RC muscles, addressing flexibility of the posterior shoulder structures, pectoralis minor muscle, the thoracic spine (with postural education), and activity modifications designed to reduce pain and disability from RC tendinopathy.30-32 There is a bias seen with exercise programs to target outlet impingement, which is an extrinsic mechanism.29 Limited evidence exists to support therapeutic exercise and manual therapy for the treatment of RC tendinopathy.2 The purpose of this clinical commentary is to present the findings of a literature review identifying various mechanisms proposed for the development of RC tendinopathy. These mechanisms, or factors associated with RC tendinopathy will then be discussed with emphasis on the supporting evidence.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 275

METHODOLOGY Pubmed, Medline, Cinahl, PEDro, and Cochrane databases were electronically searched, limiting articles to those published in the English language between the years of 2005 and 2012. Search terms included: intrinsic mechanisms, tendinopathy, stem cells, biologics, platelet-rich plasma (PRP), healing, RC tears, full-thickness tears, tests, impingement, imaging, ultrasound, magnetic resonance imaging (MRI), radiograph, shoulder advances, treatment, diagnoses, tendon disorders, pathogenesis, matrix metalloproteinase, injections, and RC repair. Over 150 abstracts were reviewed and 43 articles were analyzed for quality and relevance using the University of Alberta Evidence Based Medicine Toolkit.

DEFINING TENDINOPATHY It is important that tendinopathy, tendinitis, and tendinosis are systematically defined, in order to ensure that healthcare providers are effectively communicating regarding the condition to be treated. A tendinopathy is an overuse condition that manifests itself as pain in and around tendons28 and happens when the body fails to regenerate properly.33 This painful condition is associated with tendon disorganization and thickening that reduces its physical properties, which causes the tendon to fatigue, further exacerbating the painful condition with ultimate failure.33 Tendinitis, which is usually painful, is a generic term that has to do with overuse, irritation, strain, degeneration and poor mechanics.33 Degenerated and disorganized collagen that has increased vascularity and cellularity without obvious inflammatory cells is termed tendinosis.33,34 Tendinitis and tendinosis represent tendon pathology and are subsets of tendinopathy.29 Tendons must be able to handle tensile loads and their ability to do so relies on Type 1 collagen.35 However, a key feature of tendinopathy can be seen through collagen structure analysis by showing the disruption of tendon microarchitecture, which helps to understand the response to variable amounts of cyclic loading.35-37 The aging process and repetitive use of tendons are thought to be contributors to RC tendinopathy.35 The three general areas of tendinopathy that have been described in the literature are bursal sided, articular sided, and mid-substance.38,39 RC tendinitis is a term used to described chronic and acute conditions that involve the inflammatory pro-

cess.29 Histological research shows that there are a minimal number of inflammatory cells present in RC tendons and subacromial bursa.40 RC disease has traditionally been thought to be a progressive disorder.41 Neer believed the process started with tendonitis, then progressed to tendinosis with degeneration and partial thickness tears, and finally resulted in full thickness tears.41 RC tendinosis is the diagnostic label for tendon pathology that is degenerative with or without inflammation,29 whereas RC tendinopathy is used to signify a combination of pain and impaired performance associated with injury to the RC tendons.42,43 INTRINSIC MECHANISMS RC tendinopathy occurs for a multitude of reasons.

Intrinsic mechanisms are associated with the tendon itself and can be from aging,44,45 altered biology,46-48 microvascular blood supply,38,41,49 degeneration, tendon overload, overuse, or trauma.50-52 Intrinsic factors that contribute to RC tendon degradation with tensile/shear overload include alterations in biology, mechanical properties, morphology, and vascularity (See Table 1 for a summary of cellular changes associated with intrinsic mechanisms).29,46-48,53,54 As the human body ages, the properties of tendons are negatively impacted by processes such as calcification, fibrovascular proliferation, degeneration, decreased tensile loading, decreased toe-region on the stress strain curve, and decreased elasticity.55,46 Vascularization may be another intrinsic factor to consider.Codman described a critical zone where there was deficient blood supply within supraspinatus tendons.56 But the research of some authors refutes this thought process and describes the lack of this region of hypovascularity, or that the hypovascularity is only limited to the articular side and not the bursal side of the tendon.49,57 In RC tendinopathy, neovascularization occurs in regions that have sustained smaller tendon tears and degenerative changes.38,39,46,58-60 Levy et al showed that subjects with acute RC tendinopathy had hypovascularity in the supraspinatus tendon that compared to subjects without RC disease.58 In chronic tendinopathy, the tears showed hypervascularity near the degenerative changes.58 Thus, the literature is not clear on whether hypovascularity directly causes tendinopathy per se, but there is conjecture that the presence

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 276

Table 1. Proposed cellular changes associated with intrinsic mechanisms of rotator cuff tendinopathy

Cellular changes associated with injury, reduced mechanical stimulation, certain medications, etc.: 166-173 Increased matrix metalloproteinases (MMP); Reduced tissue inhibitors of MMP (TIMPs); Tendon cell apoptosis; Insulin-like growth factor (IGF-1); Nitric oxide synthetase (NOS); Chondroid metaplasia of the tendon and matrix changes; Fatty infiltration (following tears); Cytokines; Caspases

of blood vessels in the tendon matrix crowds out necessary collagen, which may further weaken the tendon prior to failure.61 EXTRINSIC MECHANISMS Extrinsic mechanisms for RC tendinopathy include anatomic variables that set up conditions for impingement (usually occurring at the anterior aspect of the acromion).62-64 It is currently thought that between 44-64% of all shoulder pain is from subacromial impingement syndrome (SAIS), the most common shoulder disorder.65 Seitz et al showed that anatomical variants (acromial shape, subacromial joint spurs, and AC joint spurs) can lead to RC tendinopathy29 and have proposed that these variables, along with overuse, could predispose an individual to the pathology.66 Also, the angle and shape of the acromion could be a possible cause of the pathology.29,67 The acromial shape has been broken down in to three types flat (Type 1), curved (Type 2), and hooked (Type 3).68 It is still unclear if the shape changes with age or if its shape is determined congenitally or if both may contribute to the occurrence of tendinopathy.51,69,70 Prior RC damage could cause increased stress to the coracoacromial arch and cause a hooked acromion to develop.51 Wang et al found that as age progressed so did the shape of the acromion from flat to curved or hooked.71 Shah et al found that this was possibly due to traction forces on the acromion,72 which could offer some explanation as to why there is a higher incidence of RC tears with age but still suggests an initiating intrinsic reason.51 It is believed that acro-

NOTE: All of these changes negatively affect the turnover rate of collagen, adversely affecting collagen proliferation, and likely lead to tendon changes such as degeneration and apoptosis.

mial shape and the severity of RC pathology are related.73,74 The AC joint could be another contributing factor.

Over time, this joint degenerates and osteophytes can form on the inferior aspect of the distal clavicle.69,75 These arthritic signs have been correlated with the presence of RC pathology.75 Whether bone spurs cause RC tears continues to be debated.51 The spurs are termed an enthesopathy and are thought to form from a coracoacromial ligament sprain.51 These spurs may also be a secondary formation after sustaining a bursal-side RC tear.76,77 Utilizing conservative treatment with a patient with the Type 1-acromion has a better outcome than conservative care in those with other types of acromion.78,79 The majority of patients with SAIS can be treated nonsurgically, however, many authors have demonstrated the success of a variety of surgical procedures.6 Further high-quality research is needed on the treatment and diagnosis of SAIS.6 Shoulder impingement is the main extrinsic cause of RC tendinopathy. It occurs with mechanical compression of the external portion (bursal side) of the tendon, which leads to inflammation and degeneration.41 Upon repeated occurrence, the coracoacromial ligament may thicken, decreasing the subacromial space.6 Overuse activity coupled with coracoacromial arch changes have a significant effect on tendon injury.6 Significant relationships have been demonstrated between acromion morphology, the patientâ&#x20AC;&#x2122;s self reported shoulder function, and the severity of the RC pathology.50

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 277

Decreased microvascular blood supply has been discussed as a possible cause of intrinsic pathology but it can also be from an extrinsic cause.51 For example, when the arm is in full abduction, and the supraspinatus is compressed by the humeral head, the reduction in perfusion may be significant.51 A tight posterior capsule may cause changes in GH movement which could set up the patient for the development of impingement.6 Harryman et al showed that when posterior capsule tightness was surgically induced in cadaveric specimens, there was an increase in anterior superior humeral head translation during passive GH flexion, leading to a narrowing of the subacromial space (SAS).80 Stretching should be used to address impairments in posterior shoulder tightness.81 Due to this relationship between posterior shoulder tightness and those with RC tendinopathy,82 horizontal adduction and internal rotation ROM should be examined.81,83-85 Newer models of impingement have been proposed with limited supporting evidence.51 Internal impingement (also known as posterior superior impingement or superior impingement) accounts for the majority of articular sided tears because the humeral tuberosity compresses the RC on the glenoid fossa.86 Internal impingement (extrinsic mechanism for tendinopathy) is unique and occurs in overhead throwing athletes.87-89 This is due to the extreme external rotation, abduction and extension of the arm, which can, in turn, cause the humerus to pinch the RC tendons on the superior glenoid rim.90,86 The articular side of the tendons, not the bursal side, compresses between the humerus and the upper rim of the glenoid fossa when the arm is in extension, abduction and full external rotation.6 In this case, the clinician will not usually see a narrowing of the SAS.29 Most PRCTs are articular sided as opposed to bursal-sided, are degenerative in nature, and occur before the acromion degenerates.91-93 Aberrant scapular muscle activity has been identified in patients with SAIS and has been directly linked to abnormal scapular motion.6,94-96 The serratus anterior and trapezius stabilize the scapula and induce scapular upward rotation, ER (external rotation), and/or posterior tilt, allowing the humeral head the appropriate amount of space for clearance

during elevation motions.94 Individuals can have reduced muscle performance or balance, latency in activation, and EMG (electromyography) activity of these muscles.94-96 Individuals who have some sort of impingement are thought to develop compensational movement patterns that relieve the compression and increase the subacromial space (SAS).97 Published evidence does not currently support scapular dyskinesis as a major finding and does not describe it as a prime extrinsic mechanism for individuals with RC tendinopathy.29 Scapular dyskinesis in subjects with RC tendinopathy has been theorized to include aberrant scapular and RC neuromuscular activation and muscle performance, thoracic kyphosis, pectoralis minor shortening, and posterior shoulder tightness.29 A shortened pectoralis minor muscle at rest has been indirectly correlated with RC tendinopathy, functional deficits, and pain.29,98-100 This is again thought to be attributed to abnormal scapular kinematics.29 In subjects with RC tendinopathy, it was found that the serratus anterior and lower trapezius muscles demonstrate reduced muscle force and performance.95,101 Muscle deficits, soft tissue tightness and abnormal posture directly influence shoulder kinematics.29 Weakness or dysfunction of the rotator cuff muscles can set up a situation that leads to SAIS due to a narrow SAS.6,102 Authors have shown that there is superior humeral head translation and decreased abduction torque when there is reduced force of RC muscles, especially infraspinatus.103,104 RC tendinopathy is seen in individuals with significant decreases in muscle peak isometric, eccentric and concentric torque when compared to those without these deficits.105,106 Decreased muscle co-activation ratios between subscapularis, infraspinatus, and supraspinatus during the first 30 degrees of arm elevation and an increase at above 90 degrees was seen in patients exhibiting impingement as compared to the control group with no impingement.29,107 HEALING After a tendon injury, the tendon normally heals through scar tissue formation which can take up to 24 months to fully mature.108 The types and characteristics of collagen in scar tissue are different from that which comprises normal tissue.33 A greater ratio

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 278

of Type 1 and Type 3 collagen is present in scar tissue (20-30%, instead of 1%).109 Type 3 collagen, although possessing excellent elastic properties, demonstrates inferior strength properties because the diameter of Type 3 fibers is smaller than Type 1 fibers.33 As the scar matures, it becomes much stronger because of improved interdigitation of collagen fibers and increased fiber diameter.33 However, the properties are still inferior to native tendon because of the structural organization and poor matrix formation.110 Therefore scar tissue must thicken to make up for its mechanical insufficiency, resulting in a stiffer tendon.33 Subjects who use tobacco products (e.g., cigarettes) are at greater risk for RC disease and poorer surgical outcomes.111,112 This relationship becomes stronger as the dose and length of exposure increases.51 Nicotine induces vasconstriction, which decreases oxygen delivery, and carbon monoxide reduces cellular oxygen levels.113,114 Nicotine also contributes to a decrease in collagen concentrations, mechanical properties, deposition and repair after surgical intervention, while also causing unrelenting inflammation.115,116 Postoperative outcomes of smokers are poorer than nonsmokers in terms of pain levels, postoperative satisfaction and overall function.112 Metabolic diseases can also negatively impact tendon healing and have a higher rate of complications, including infections (10%) and failures (7%).51,117 Gharaibeh et al stated “In vitro experiments showed that a Cox-2- specific inhibitor (NS-398) slows the proliferation and maturation of differentiated myogenic precursor cells and thus delays the regenerative myogenesis process.”118 This may impair skeletal muscle healing.118 Similar results have been seen using the Cox-2 selective inhibitor SC-236.119 Even in highly vascularized skeletal muscle, NSAIDs seem to impair the healing process and may affect the recovery of other soft tissues.118 HEALING: QUANTIFYING LEVELS OF MATRIX METALLOPROTEINASE – 13 (MMP-13) MMPs, aka zinc dependent proteases, are important for tendon repair and are associated with tenocyte cellular changes (see Table 1). Elevated levels of MMP-13, determined through equalized protein extracts in an enzyme-linked immunosorbent assay, could be an indicator of an impending tear

because they play a critical role in the degradation process of RC tissue. Appropriate pharmacological management is important, as ibuprofen appears to be associated with upregulation of MMP-13 and other enzymes associated with collagen-degradation.120 If MMP-13 activity is unchecked, then tears can occur.121-123 Furthermore, MMP-13 levels show a significant relationship with patients’ pain ratings,121 and it has been observed that MMP-13 contributes to the inflammation found in OA (Osteoarthritis), RA (Rheumatoid arthritis), and periodontal disease and is found at increased levels in full thickness RC tears.35,123-125 EVIDENCE IN IMAGING The function of the upper limb is critical in deciding the treatment approach and determining the patient’s prognosis.126 Clinical evaluation of the shoulder correlates well with magnetic resonance imaging (MRI) findings.126 MRI and ultrasound have comparably high accuracy for finding RC tears and biceps pathologies,126-130 clinical tests have moderate accuracy for both conditions.126 Patients with RC tendinopathy will not always show significant narrowing in SAS with the arm at rest.131133 Clinicians should look at the active range of motion biomechanics and then examine the SAS.134 Glenohumeral internal and external rotation have opposing effects on subacromial pressure with external rotation decreasing the pressure in this space.135,136 Some MRI studies show that active arm elevation reduces the acromial humeral distance (AHD) in those with RC tendinopathy but more research is necessary.134,137 AHD is the shortest distance between the acromion and the humerus and the term can be used interchangeably with acromial humeral interval.Ardic et al found that the basic office clinic exam (not radiography or ultrasound) has 78.3% sensitivity for patients with subacromial impingement syndrome.126 Advanced imaging plays an essential role when conservative therapy approaches fail after three weeks.126 Clinical exam impingement tests have 71.2% accuracy, far better than the 40.7% accuracy of Speed’s test for an injured biceps tendon.126 Musculoskeletal ultrasound had 93.2% accuracy in finding RC tears and was 100% accurate in displaying biceps pathology.126 MRI has been shown to be superior to ultrasonography for the detection of overall pathologies, except when there is

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 279

damage to the biceps tendon.126 Some studies found that ultrasonography and MRI had no significant difference when comparing their sensitivity and specificity ratings.127,128,130 Ultrasongraphy, however, is poorly correlated with surgery or arthrography for diagnosing RC tears.126,138-140 When measuring the coracoacromial arch in relation to the humerus and the AHD both have a similar measurements and can vary from 1.0 to 1.5 cm as seen on radiographs.6 Some studies place the AHD for healthy shoulders between 0.7 cm and 1.4 cm when viewed with ultrasonography, radiography, and MRI.6 When the AHD is less than 0.7 cm with the arm resting, a less favorable surgical outcome can be predicted.141 Mayerhoefer et al. stated that AHD and measurements of the acromial shape do not correlate using radiography or MRI and that the acromial shape does not actually mean that the subacromial space is smaller.142 This means that just because an acromion has a particular shape that it does not mean that the subacromial space is smaller or the acromial humeral distance is reduced.

The lateral acromial angle (LAA) is the relationship between the scapular glenoid plane and the slope of the inferior surface of the acromion. The LAA and acromial humeral interval (AHI) are reliable techniques when measured objectively on X-ray and MRI and their reliability increases with experienced observers.143 LAA measurements have shown that a downsloping acromion correlates to an increased incidence of RC tears.143-145 The significance of the AHI needs more research in examining its connection to impingement syndrome.143 INJECTIONS Various injections can and have been used to aid in the diagnosis or treatment of RC tendinopathy. Andres et al found that corticosteroid injections relieve pain in cases of tendinitis for up to six Proposed cellular changes associated with intrinsic mechanisms of rotator cuff tendinopathy weeks, but there is no evidence for benefit beyond six months.28,146-148 Arroll et al observed that corticosteroid injections into the SAS for RC tendinitis can be effective for up to nine months.149 It is thought that higher doses may be more effective than lower doses and that the injections are most likely more effective than NSAIDs.149 Additionally, accuracy

can be improved when using ultrasound guidance to ensure effective injection placement, which could help to improve outcomes.150,151 Bursal-sided PRCTs should receive a subacromial injection whereas intra-articular injections provide greater pain relief for articular sided PRCTs or in patients with PRCTs along with other conditions such as capsulitis.2 An indirect suprascapular nerve block may improve pain levels, allowing greater compliance with a rehabilitation program and improving comfort when sleeping.2 PLATELET-RICH PLASMA Platelet-rich plasma (PRP) is developed from autologous blood injections152 with the aim of improving tendon healing.152 Evidence points to specific growth factors within the blood that promote the healing process, but evidence refutes the effects of using whole blood injections.152,153 When using PRP, the platelets add more growth factors to the injection site for seven to ten days.152 These growth factors are transforming growth factor b1 (TBFb), plateletderived growth factor, vascular endothelial growth factor, hepatocyte growth factor, and insulin-like growth factor 1.152 These factors are biologically active and stimulate angiogenesis, epithelialization, cell differentiation, proliferation, and the formation of extracellular matrix and fibrovascular callus.154-156 Previous studies examining tenocyte cultures showed that cell proliferation and total collagen production was enhanced with platelet-rich plasmaclot releasate (PRCR).157,158 Recent studies provide evidence that PRP treatment in vivo may enhance tendon healing by increasing tenocyte number and production of collagen (types 1 and 3), which makes up a major portion of the tendon.110,159 PRP can be used to enhance extracellular matrix organization in the short term.152 Injections given one week post-op showed increased tendon strength after four weeks when combined with early therapy.160 There are have been no adverse effects reported after treatment.152 Some low level evidence exists of improved healing times and increased strength, and in some cases subjects have avoided surgery.152 It has also been used as a safe adjunct to surgery to improve healing.152 No studies exist proving that the use of NSAIDS affect the efficacy of PRP but it is currently recommended that NSAIDS

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 280

should not be taken 2 days before or 14 days after the injections.152 At this point, there is only limited clinical support for PRP when used for RC repair and cartilage healing, although it is safe for clinical use.13 STEM CELLS AND BIOLOGIC AIDS Stem cell research is rapidly evolving and the literature is uncovering evidence that could greatly improve the treatment of tendinopathy through cell therapy.33 The evidence is currently limited in humans and not many clinical trials exist,33 thus, discussion of this area will be limited.

Surgical repair failure rates range from 20 to 70%, which can be attributed to a host of factors.22,161,162 Biologically engineered scaffolds, exogenous growth factors, and stem cells may show potential when used to encourage RC repair and tendon healing.163-165 The best way to improve tendon healing is probably through a mixture of different growth factors, but the precise combination is unknown.165 The optimal proportion of catabolic and anabolic factors will create conditions for a superior repair and encourage the redevelopment of glenohumeral cartilage and tendon to bone insertion.13,165 Greater research is still needed encompassing animal and human trials.

CONCLUSION The common belief is that tendinopathy is generated from multivariate etiology. It is increasingly evident that intrinsic mechanisms play a greater role than extrinsic mechanisms in this process. Emphasis should be given on the evidence from patient information and imaging/injection techniques in order to aid in diagnosis of RC tendinopathy. It is the belief of the authors of this commentary that increased effort and research should be placed into future treatment technologies such as cell therapy and biological engineering in order to attempt to improve patient outcomes and quality of life.

REFERENCES 1. Urwin M, Symmons D, Allison T, et al. Estimating the burden of musculoskeletal disorders in the community: the comparative prevalence of symptoms at different anatomical sites, and the relation to social deprivation. Annals of the rheumatic diseases. Nov 1998;57(11):649-655.

2. Shin KM. Partial-thickness rotator cuff tears. The Korean journal of pain. Jun 2011;24(2):69-73.

3. Codman EA. Complete rupture of the supraspinatus tendon. Operative treatment with report of two successful cases. 1911. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Apr 2011;20(3):347-349.

4. Jozsa L, Kannus P. Histopathological findings in spontaneous tendon ruptures. Scand J Med Sci Sports.

Apr 1997;7(2):113-118.

5. Murrell GA, Walton JR. Diagnosis of rotator cuff tears. Lancet. Mar 10 2001;357(9258):769-770.

6. Umer M, Qadir I, Azam M. Subacromial impingement syndrome. Orthopedic reviews. May 9 2012;4(2):e18.

7. Fukuda H. Partial-thickness rotator cuff tears: a modern view on Codman’s classic. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Mar-Apr 2000;9(2):163-168.

8. Goutallier D, Postel JM, Gleyze P, Leguilloux P, Van Driessche S. Influence of cuff muscle fatty degeneration on anatomic and functional outcomes after simple suture of full-thickness tears. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Nov-Dec 2003;12(6):550554.

9. Liem D, Lichtenberg S, Magosch P, Habermeyer P. Magnetic resonance imaging of arthroscopic supraspinatus tendon repair. The Journal of bone and joint surgery. American volume. Aug 2007;89(8): 1770-1776.

10. Vitale MA, Vitale MG, Zivin JG, Braman JP, Bigliani LU, Flatow EL. Rotator cuff repair: an analysis of utility scores and cost-effectiveness. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Mar-Apr 2007;16(2):181-187.

11. Accousti KJ, Flatow EL. Technical pearls on how to maximize healing of the rotator cuff. Instructional course lectures. 2007;56:3-12.

12. Cofield RH, Parvizi J, Hoffmeyer PJ, Lanzer WL, Ilstrup DM, Rowland CM. Surgical repair of chronic rotator cuff tears. A prospective long-term study. The Journal of bone and joint surgery. American volume.

Jan 2001;83-A(1):71-77.

13. Killian ML, Cavinatto L, Galatz LM, Thomopoulos S. Recent advances in shoulder research. Arthritis research & therapy. Jun 15 2012;14(3):214.

14. Galatz LM, Ball CM, Teefey SA, Middleton WD, Yamaguchi K. The outcome and repair integrity of completely arthroscopically repaired large and massive rotator cuff tears. The Journal of bone and joint surgery. American volume. Feb 2004;86-A(2):219-224.

15. Harryman DT, 2nd, Mack LA, Wang KY, Jackins SE, Richardson ML, Matsen FA, 3rd. Repairs of the rotator cuff. Correlation of functional results with

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 281

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

integrity of the cuff. The Journal of bone and joint surgery. American volume. Aug 1991;73(7):982-989.

Koh KH, Kang KC, Lim TK, Shon MS, Yoo JC. Prospective randomized clinical trial of singleversus double-row suture anchor repair in 2- to 4-cm rotator cuff tears: clinical and magnetic resonance imaging results. Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. Apr 2011;27(4):453-462.

Chaudhury S, Carr AJ. Lessons we can learn from gene expression patterns in rotator cuff tears and tendinopathies. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Feb 2012;21(2):191-199.

Charousset C, Bellaiche L, Kalra K, Petrover D. Arthroscopic repair of full-thickness rotator cuff tears: is there tendon healing in patients aged 65 years or older? Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. Mar 2010;26(3):302-309.

Dodson CC, Kitay A, Verma NN, et al. The long-term outcome of recurrent defects after rotator cuff repair.

Am J Sports Med. Jan 2010;38(1):35-39.

Duquin TR, Buyea C, Bisson LJ. Which method of rotator cuff repair leads to the highest rate of structural healing? A systematic review. Am J Sports Med. Apr 2010;38(4):835-841.

Jost B, Zumstein M, Pfirrmann CW, Gerber C. Longterm outcome after structural failure of rotator cuff repairs. The Journal of bone and joint surgery.

American volume. Mar 2006;88(3):472-479.

Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? The Journal of bone and joint surgery. American volume. Jun 2005;87(6):1229-1240.

Tashjian RZ, Hollins AM, Kim HM, et al. Factors affecting healing rates after arthroscopic double-row rotator cuff repair. Am J Sports Med. Dec 2010;38(12):2435-2442.

Thomazeau H, Boukobza E, Morcet N, Chaperon J, Langlais F. Prediction of rotator cuff repair results by magnetic resonance imaging. Clinical orthopaedics and related research. Nov 1997(344):275-283.

Bigliani LU, Cordasco FA, McIlveen SJ, Musso ES. Operative treatment of failed repairs of the rotator cuff. The Journal of bone and joint surgery. American volume. Dec 1992;74(10):1505-1515.

DeOrio JK, Cofield RH. Results of a second attempt at surgical repair of a failed initial rotator-cuff repair.

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

The Journal of bone and joint surgery. American volume. Apr 1984;66(4):563-567.

Flugstad D, Matsen F, Larry I, Jackins S. Failed acromioplasty: Etiology and prevention. Orthop Trans. 1986;10:229.

Andres BM, Murrell GA. Treatment of tendinopathy: what works, what does not, and what is on the horizon. Clinical orthopaedics and related research. Jul 2008;466(7):1539-1554.

Seitz AL, McClure PW, Finucane S, Boardman ND, 3rd, Michener LA. Mechanisms of rotator cuff tendinopathy: intrinsic, extrinsic, or both? Clin Biomech (Bristol, Avon). Jan 2011;26(1):1-12.

Brox J, Staff P, Ljunggren A, Brevik J. Arthroscopic surgery compared with supervised exercises in patients with rotator cuff disease (stage II impingement syndrome). BMJ. 1993;307, 899-903.

Haahr JP, Ostergaard S, Dalsgaard J, et al. Exercises versus arthroscopic decompression in patients with subacromial impingement: a randomised, controlled study in 90 cases with a one year follow up. Annals of the rheumatic diseases. May 2005;64(5):760-764.

Lombardi JI, Magri AG, Fleury AM, Da Silva AC, Natour J, 59. Progressive resistance training in patients with shoulder impingement syndrome: a randomized controlled trial. Arthritis Rheum.

2008;59, 615-622.

Obaid H, Connell D. Cell therapy in tendon disorders: what is the current evidence? Am J Sports Med. Oct 2010;38(10):2123-2132.

Khan KM, Cook JL, Bonar F, Harcourt P, Astrom M. Histopathology of common tendinopathies. Update and implications for clinical management. Sports Med. Jun 1999;27(6):393-408.

Neviaser A, Andarawis-Puri N, Flatow E. Basic mechanisms of tendon fatigue damage. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Feb 2012;21(2):158-163.

Arya S, Kulig K. Tendinopathy alters mechanical and material properties of the Achilles tendon. J Appl Physiol. Mar 2010;108(3):670-675.

Longo UG, Franceschi F, Ruzzini L, et al.

Histopathology of the supraspinatus tendon in rotator cuff tears. Am J Sports Med. Mar 2008;36(3):533-538.

Fukuda H, Hamada K, Yamanaka K. Pathology and pathogenesis of bursal-side rotator cuff tears viewed from en bloc histologic sections. Clinical orthopaedics and related research. May 1990(254):75-80.

Hashimoto T, Nobuhara K, Hamada T. Pathologic evidence of degeneration as a primary cause of rotator cuff tear. Clinical orthopaedics and related research. Oct 2003(415):111-120.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 282

40. Sarkar K, Uhthoff HK. Ultrastructure of the subacromial bursa in painful shoulder syndromes.

Virchows Archiv. A, Pathological anatomy and histopathology. 1983;400(2):107-117.

41. Biberthaler P, Wiedemann E, Nerlich A, et al.

Microcirculation associated with degenerative rotator cuff lesions. In vivo assessment with orthogonal polarization spectral imaging during arthroscopy of the shoulder. The Journal of bone and joint surgery.

American volume. Mar 2003;85-A(3):475-480.

42. Alfredson H. Chronic midportion Achilles tendinopathy: an update on research and treatment.

Clinics in sports medicine. Oct 2003;22(4):727-741.

43. Alfredson H. The chronic painful Achilles and patellar tendon: research on basic biology and treatment. Scand J Med Sci Sports. Aug 2005;15(4):252-259.

44. Milgrom C, Schaffler M, Gilbert S, van Holsbeeck M. Rotator-cuff changes in asymptomatic adults. The effect of age, hand dominance and gender. The Journal of bone and joint surgery. British volume. Mar 1995;77(2):296-298.

45. Tempelhof S, Rupp S, Seil R. Age-related prevalence of rotator cuff tears in asymptomatic shoulders.

Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Jul-Aug 1999;8(4):296-299.

46. Kumagai J, Sarkar K, Uhthoff HK. The collagen types in the attachment zone of rotator cuff tendons in the elderly: an immunohistochemical study.

The Journal of rheumatology. Nov 1994;21(11):20962100.

47. Riley GP, Harrall RL, Constant CR, Chard MD, Cawston TE, Hazleman BL. Glycosaminoglycans of human rotator cuff tendons: changes with age and in chronic rotator cuff tendinitis. Annals of the rheumatic diseases. Jun 1994;53(6):367-376.

48. Riley GP, Harrall RL, Constant CR, Chard MD, Cawston TE, Hazleman BL. Tendon degeneration and chronic shoulder pain: changes in the collagen composition of the human rotator cuff tendons in rotator cuff tendinitis. Annals of the rheumatic diseases. Jun 1994;53(6):359-366.

49. Rudzki JR, Adler RS, Warren RF, et al. Contrastenhanced ultrasound characterization of the vascularity of the rotator cuff tendon: age- and activity-related changes in the intact asymptomatic rotator cuff. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. JanFeb 2008;17(1 Suppl):96S-100S. 50. Michener LA, McClure PW, Karduna AR. Anatomical and biomechanical mechanisms of subacromial impingement syndrome. Clin Biomech (Bristol, Avon).

Jun 2003;18(5):369-379.

51. Maffulli N, Longo UG, Berton A, Loppini M, Denaro V. Biological factors in the pathogenesis of rotator cuff tears. Sports medicine and arthroscopy review. Sep 2011;19(3):194-201.

52. Almekinders LC, Weinhold PS, Maffulli N. Compression etiology in tendinopathy. Clinics in sports medicine. Oct 2003;22(4):703-710.

53. Bey MJ, Song HK, Wehrli FW, Soslowsky LJ. Intratendinous strain fields of the intact supraspinatus tendon: the effect of glenohumeral joint position and tendon region. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. Jul 2002;20(4):869-874.

54. Malliaras P, Purdam C, Maffulli N, Cook J. Temporal sequence of greyscale ultrasound changes and their relationship with neovascularity and pain in the patellar tendon. British journal of sports medicine. Oct 2010;44(13):944-947.

55. Woo SL, An KN, Frank CB, Livesay GA, Ma CB, Zeminski J, et al. Anatomy, biology, and biomechanics of tendon and ligament. American Academy of Orthopaedic Surgeons. 2000.

56. Codman EA. The shoulder; rupture of the supraspinatus tendon and other lesions in or about the subacromial bursa. Boston, Mass.: T. Todd company; 1934.

57. Lohr JF, Uhthoff HK. The microvascular pattern of the supraspinatus tendon. Clinical orthopaedics and related research. May 1990(254):35-38.

58. Levy O, Relwani J, Zaman T, Even T, Venkateswaran B, Copeland S. Measurement of blood flow in the rotator cuff using laser Doppler flowmetry. The Journal of bone and joint surgery. British volume. Jul 2008;90(7):893-898.

59. Goodmurphy CW, Osborn J, Akesson EJ, Johnson S, Stanescu V, Regan WD. An immunocytochemical analysis of torn rotator cuff tendon taken at the time of repair. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. JulAug 2003;12(4):368-374.

60. Rathbun JB, Macnab I. The microvascular pattern of the rotator cuff. The Journal of bone and joint surgery.

British volume. Aug 1970;52(3):540-553.

61. Abate M, Gravare Silbernagel K, Siljeholm C, et al.

Pathogenesis of tendinopathies: inflammation or degeneration? Arthritis research & therapy.

2009;11(3):235.

62. Neer CS, 2nd. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. The Journal of bone and joint surgery. American volume. Jan 1972;54(1):41-50.

63. Brossmann J, Preidler KW, Pedowitz RA, White LM, Trudell D, Resnick D. Shoulder impingement

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 283

64.

65.

66.

67.

syndrome: influence of shoulder position on rotator cuff impingement--an anatomic study. AJR. American journal of roentgenology. Dec 1996;167(6):1511-1515.

Yamamoto N, Muraki T, Sperling JW, et al.

Impingement mechanisms of the Neer and Hawkins signs. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. NovDec 2009;18(6):942-947. van der Windt DA, Koes BW, de Jong BA, Bouter LM. Shoulder disorders in general practice: incidence, patient characteristics, and management. Annals of the rheumatic diseases. Dec 1995;54(12):959-964.

Soslowsky LJ, Thomopoulos S, Esmail A, et al.

Rotator cuff tendinosis in an animal model: role of extrinsic and overuse factors. Annals of biomedical engineering. Sep 2002;30(8):1057-1063.

Vaz S, Soyer J, Pries P, Clarac JP. Subacromial impingement: influence of coracoacromial arch geometry on shoulder function. Joint, bone, spine : revue du rhumatisme. 2000;67(4):305-309.

68. Bigliani LU, Morrison DS, April EW. The morphology of the acromion and its relationship to rotator cuff tears. Orthop Trans. 1986;10, 228.

69. Nicholson GP, Goodman DA, Flatow EL, Bigliani LU. The acromion: morphologic condition and agerelated changes. A study of 420 scapulas. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Jan-Feb 1996;5(1): 1-11.

70. Bonsell S, Pearsall AWt, Heitman RJ, Helms CA, Major NM, Speer KP. The relationship of age, gender, and degenerative changes observed on radiographs of the shoulder in asymptomatic individuals. The Journal of bone and joint surgery. British volume. Nov 2000;82(8):1135-1139.

71. Wang JC, Shapiro MS. Changes in acromial morphology with age. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Jan-Feb 1997;6(1):55-59.

72. Shah NN, Bayliss NC, Malcolm A. Shape of the acromion: congenital or acquired--a macroscopic, radiographic, and microscopic study of acromion.

Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Jul-Aug 2001;10(4):309-316.

73. Bigliani LU, Ticker JB, Flatow EL, Soslowsky LJ, Mow VC. The relationship of acromial architecture to rotator cuff disease. Clinics in sports medicine. Oct 1991;10(4):823-838.

74. Ogawa K, Yoshida A, Inokuchi W, Naniwa T. Acromial spur: relationship to aging and morphologic changes in the rotator cuff. Journal of shoulder and elbow

75.

76.

77.

78.

79.

80.

81.

82.

83.

84.

85.

surgery / American Shoulder and Elbow Surgeons ... [et al.]. Nov-Dec 2005;14(6):591-598.

Cuomo F, Kummer FJ, Zuckerman JD, Lyon T, Blair B, Olsen T. The influence of acromioclavicular joint morphology on rotator cuff tears. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Nov-Dec 1998;7(6):555-559.

Ozaki J, Fujimoto S, Nakagawa Y, Masuhara K, Tamai S. Tears of the rotator cuff of the shoulder associated with pathological changes in the acromion. A study in cadavera. The Journal of bone and joint surgery.

American volume. Sep 1988;70(8):1224-1230.

Chambler AF, Pitsillides AA, Emery RJ. Acromial spur formation in patients with rotator cuff tears.

Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Jul-Aug 2003;12(4):314-321.

Morrison DS, Frogameni AD, Woodworth P. Nonoperative treatment of subacromial impingement syndrome. The Journal of bone and joint surgery.

American volume. May 1997;79(5):732-737.

Wang JC, Horner G, Brown ED, Shapiro MS. The relationship between acromial morphology and conservative treatment of patients with impingement syndrome. Orthopedics. 2000;23, 557– 559.

Harryman DT, 2nd, Sidles JA, Clark JM, McQuade KJ, Gibb TD, Matsen FA, 3rd. Translation of the humeral head on the glenoid with passive glenohumeral motion. The Journal of bone and joint surgery. American volume. Oct 1990;72(9):1334-1343.

Myers JB, Oyama S, Wassinger CA, et al. Reliability, precision, accuracy, and validity of posterior shoulder tightness assessment in overhead athletes.

Am J Sports Med. Nov 2007;35(11):1922-1930.

Borich MR, Bright JM, Lorello DJ, Cieminski CJ, Buisman T, Ludewig PM. Scapular angular positioning at end range internal rotation in cases of glenohumeral internal rotation deficit. The Journal of orthopaedic and sports physical therapy. Dec 2006;36(12):926-934.

Laudner KG, Stanek JM, Meister K. Assessing posterior shoulder contracture: the reliability and validity of measuring glenohumeral joint horizontal adduction. Journal of athletic training. Oct-Dec 2006;41(4):375-380.

Tyler TF, Roy T, Nicholas SJ, Gleim GW. Reliability and validity of a new method of measuring posterior shoulder tightness. The Journal of orthopaedic and sports physical therapy. May 1999;29(5):262-269; discussion 270-264.

Warner JJ, Micheli LJ, Arslanian LE, Kennedy J, Kennedy R. Patterns of flexibility, laxity, and

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 284

86.

87.

88.

89.

90.

91.

92.

93.

94.

95.

strength in normal shoulders and shoulders with instability and impingement. Am J Sports Med. JulAug 1990;18(4):366-375.

Edelson G, Teitz C. Internal impingement in the shoulder. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. JulAug 2000;9(4):308-315.

Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology Part III: The SICK scapula, scapular dyskinesis, the kinetic chain, and rehabilitation. Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. Jul-Aug 2003;19(6):641-661.

Jobe CM. Posterior superior glenoid impingement: expanded spectrum. Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. Oct 1995;11(5):530-536.

Kibler WB. The role of the scapula in athletic shoulder function. Am J Sports Med. 1998;26, 325-337.

Davidson PA, Elattrache NS, Jobe CM, Jobe FW. Rotator cuff and posterior-superior glenoid labrum injury associated with increased glenohumeral motion: a new site of impingement. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Sep-Oct 1995;4(5):384-390.

Loehr J, Uhthoff H. The pathogenesis of degenerative rotator cuff tears. Orthopedic Trans.

1987;11:237.

Ogata S, Uhthoff HK. Acromial enthesopathy and rotator cuff tear. A radiologic and histologic postmortem investigation of the coracoacromial arch. Clinical orthopaedics and related research. May 1990(254):39-48.

Sano H, Ishii H, Trudel G, Uhthoff HK. Histologic evidence of degeneration at the insertion of 3 rotator cuff tendons: a comparative study with human cadaveric shoulders. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Nov-Dec 1999;8(6):574-579.

Diederichsen LP, Norregaard J, Dyhre-Poulsen P, et al. The activity pattern of shoulder muscles in subjects with and without subacromial impingement. Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. Oct 2009;19(5): 789-799.

Cools AM, Witvrouw EE, Declercq GA, Vanderstraeten GG, Cambier DC. Evaluation of isokinetic force production and associated muscle

activity in the scapular rotators during a protractionretraction movement in overhead athletes with impingement symptoms. British journal of sports medicine. Feb 2004;38(1):64-68.

96. Moraes GF, Faria CD, Teixeira-Salmela LF. Scapular muscle recruitment patterns and isokinetic strength ratios of the shoulder rotator muscles in individuals with and without impingement syndrome. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Jan-Feb 2008;17(1 Suppl): 48S-53S. 97. McClure PW, Michener LA, Karduna AR. Shoulder function and 3-dimensional scapular kinematics in people with and without shoulder impingement syndrome. Physical therapy. Aug 2006;86(8):1075-1090.

98. Brox JI, Staff PH, Ljunggren AE, Brevik JI. Arthroscopic surgery compared with supervised exercises in patients with rotator cuff disease (stage II impingement syndrome). BMJ. Oct 9 1993;307(6909):899-903.

99. Kuhn JE. Exercise in the treatment of rotator cuff impingement: a systematic review and a synthesized evidence-based rehabilitation protocol. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Jan-Feb 2009;18(1):138-160.

100. Lombardi I, Jr., Magri AG, Fleury AM, Da Silva AC, Natour J. Progressive resistance training in patients with shoulder impingement syndrome: a randomized controlled trial. Arthritis Rheum. May 15 2008;59(5):615-622.

101. Cools AM, Witvrouw EE, Declercq GA, Danneels LA, Cambier DC. Scapular muscle recruitment patterns: trapezius muscle latency with and without impingement symptoms. Am J Sports Med. Jul-Aug 2003;31(4):542-549.

102. Reddy AS, Mohr KJ, Pink MM, Jobe FW. Electromyographic analysis of the deltoid and rotator cuff muscles in persons with subacromial impingement. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.].

Nov-Dec 2000;9(6):519-523.

103. Hurschler C, Wulker N, Mendila M. The effect of negative intraarticular pressure and rotator cuff force on glenohumeral translation during simulated active elevation. Clin Biomech. 2000;15, 306-314.

104. Mura N, O’Driscoll SW, Zobitz ME, Heers G, Jenkyn TR, Chou SM, et al. The effect of infraspinatus disruption on glenohumeral torque and superior migration of the humeral head: a biomechanical study. J. Shoulder Elbow Surg. 2003;12, 179-184.

105. Leroux JL, Codine P, Thomas E, Pocholle M, Mailhe D, Blotman F. Isokinetic evaluation of rotational strength in normal shoulders and shoulders with

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 285

impingement syndrome. Clinical orthopaedics and related research. Jul 1994(304):108-115.

106. Tyler TF, Nahow RC, Nicholas SJ, McHugh MP. Quantifying shoulder rotation weakness in patients with shoulder impingement. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Nov-Dec 2005;14(6):570-574.

107. Myers JB, Hwang JH, Pasquale MR, Blackburn JT, Lephart SM. Rotator cuff coactivation ratios in participants with subacromial impingement syndrome. Journal of science and medicine in sport / Sports Medicine Australia. Nov 2009;12(6):603-608.

108. Goodship A, Birch H, AM W. The pathobiology and repair of tendon and ligament injury. Vet Clin North Am Equine Pract. 10:323-349. 1994.

109. Williams IF, Heaton A, McCullagh KG. Cell morphology and collagen types in equine tendon scar.

Research in veterinary science. May 1980;28(3):302-310.

110. Wang JH. Mechanobiology of tendon. Journal of biomechanics. 2006;39(9):1563-1582.

111. Baumgarten KM, Gerlach D, Galatz LM, et al.

Cigarette smoking increases the risk for rotator cuff tears. Clinical orthopaedics and related research. Jun 2010;468(6):1534-1541.

112. Mallon WJ, Misamore G, Snead DS, Denton P. The impact of preoperative smoking habits on the results of rotator cuff repair. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Mar-Apr 2004;13(2):129-132.

113. Mosley L, Fineseth F. Cigarette smoking: impairment of digital blood flow and wound healing in the hand. 9:97-101. 1977.

114. Leow YH, Maibach HI. Cigarette smoking, cutaneous vasculature, and tissue oxygen. Clinics in dermatology. Sep-Oct 1998;16(5):579-584.

115. Galatz LM, Silva MJ, Rothermich SY, Zaegel MA, Havlioglu N, Thomopoulos S. Nicotine delays tendon-to-bone healing in a rat shoulder model. The Journal of bone and joint surgery. American volume.

Sep 2006;88(9):2027-2034.

116. Jorgensen LN, Kallehave F, Christensen E, Siana JE, Gottrup F. Less collagen production in smokers.

Surgery. Apr 1998;123(4):450-455.

117. Chen AL, Shapiro JA, Ahn AK, Zuckerman JD, Cuomo F. Rotator cuff repair in patients with type I diabetes mellitus. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Sep-Oct 2003;12(5):416-421.

118. Gharaibeh B, Chun-Lansinger Y, Hagen T, et al.

Biological approaches to improve skeletal muscle healing after injury and disease. Birth defects research. Part C, Embryo today : reviews. Mar 2012;96(1):82-94.

119. Bondesen B, Mills S, Kegley K, Pavlath G. The COX2 pathway is essential during early stages of skeletal muscle regeneration. Am J Physiol Cell Physiol.

2004;287:C475–C483.

120. Tsai WC, Hsu CC, Chang HN, Lin YC, Lin MS, Pang JH. Ibuprofen upregulates expressions of matrix metalloproteinase-1, -8, -9, and -13 without affecting expressions of types I and III collagen in tendon cells. J Orthop Res. Apr 2010;28(4):487-491.

121. Jacob J, Eisemon E, Sheibani-Rad S, Patel A, Jacob T, Choueka J. Matrix metalloproteinase levels as a marker for rotator cuff tears. Orthopedics. Apr 2012;35(4):e474-478.

122. Bedi A, Kovacevic D, Hettrich C, et al. The effect of matrix metalloproteinase inhibition on tendon-tobone healing in a rotator cuff repair model. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Apr 2010;19(3):384-391.

123. Lo IK, Marchuk LL, Hollinshead R, Hart DA, Frank CB. Matrix metalloproteinase and tissue inhibitor of matrix metalloproteinase mRNA levels are specifically altered in torn rotator cuff tendons. Am J Sports Med. Jul-Aug 2004;32(5):1223-1229.

124. Vincenti MP, Brinckerhoff CE. Transcriptional regulation of collagenase (MMP-1, MMP-13) genes in arthritis: integration of complex signaling pathways for the recruitment of gene-specific transcription factors. Arthritis research.

2002;4(3):157-164.

125. Hernandez M, Valenzuela MA, Lopez-Otin C, et al.

Matrix metalloproteinase-13 is highly expressed in destructive periodontal disease activity. Journal of periodontology. Nov 2006;77(11):1863-1870.

126. Ardic F, Kahraman Y, Kacar M, Kahraman MC, Findikoglu G, Yorgancioglu ZR. Shoulder impingement syndrome: relationships between clinical, functional, and radiologic findings.

American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. Jan 2006;85(1):53-60.

127. Swen WA, Jacobs JW, Algra PR, et al. Sonography and magnetic resonance imaging equivalent for the assessment of full-thickness rotator cuff tears.

Arthritis Rheum. Oct 1999;42(10):2231-2238.

128. Kluger R, Mayrhofer R, Kroner A, et al. Sonographic versus magnetic resonance arthrographic evaluation of full-thickness rotator cuff tears in millimeters.

Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. Mar-Apr 2003;12(2):110-116.

129. Strobel K, Zanetti M, Nagy L, Hodler J. Suspected rotator cuff lesions: tissue harmonic imaging versus conventional US of the shoulder. Radiology. Jan 2004;230(1):243-249.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 286

130. Teefey SA, Rubin DA, Middleton WD, Hildebolt CF, Leibold RA, Yamaguchi K. Detection and quantification of rotator cuff tears. Comparison of ultrasonographic, magnetic resonance imaging, and arthroscopic findings in seventy-one consecutive cases. The Journal of bone and joint surgery. American volume. Apr 2004;86-A(4):708-716.

131. Azzoni R, Cabitza P. Sonographic versus radiographic measurement of the subacromial space width. La Chirurgia degli organi di movimento. Apr-Jun 2004;89(2):143-150.

132. Azzoni R, Cabitza P, Parrini M. Sonographic evaluation of subacromial space. Ultrasonics. Apr 2004;42(1-9):683-687.

133. Desmeules F, Minville L, Riederer B, Cote CH, Fremont P. Acromio-humeral distance variation measured by ultrasonography and its association with the outcome of rehabilitation for shoulder impingement syndrome. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine. Jul 2004;14(4):197-205.

134. Graichen H, Bonel H, Stammberger T, et al. Threedimensional analysis of the width of the subacromial space in healthy subjects and patients with impingement syndrome. AJR. American journal of roentgenology. Apr 1999;172(4):1081-1086.

135. Lewis JS. Rotator cuff tendinopathy: a model for the continuum of pathology and related management.

British journal of sports medicine. Oct 2010;44(13):918-923.

136. Werner CM, Blumenthal S, Curt A, Gerber C. Subacromial pressures in vivo and effects of selective experimental suprascapular nerve block.

Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. May-Jun 2006;15(3):319-323.

137. Hebert LJ, Moffet H, Dufour M, Moisan C. Acromiohumeral distance in a seated position in persons with impingement syndrome. Journal of magnetic resonance imaging : JMRI. Jul 2003;18(1):72-79.

138. Nelson MC, Leather GP, Nirschl RP, Pettrone FA, Freedman MT. Evaluation of the painful shoulder.

A prospective comparison of magnetic resonance imaging, computerized tomographic arthrography, ultrasonography, and operative findings. The Journal of bone and joint surgery. American volume. Jun 1991;73(5):707-716.

139. Martin-Hervas C, Romero J, Navas-Acien A, Reboiras JJ, Munuera L. Ultrasonographic and magnetic resonance images of rotator cuff lesions compared with arthroscopy or open surgery findings. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. SepOct 2001;10(5):410-415.

140. Burk DL, Jr., Karasick D, Kurtz AB, et al. Rotator cuff tears: prospective comparison of MR imaging with arthrography, sonography, and surgery. AJR. American journal of roentgenology. Jul 1989;153(1):87-92.

141. Weiner DS, Macnab I. Superior migration of the humeral head. A radiological aid in the diagnosis of tears of the rotator cuff. The Journal of bone and joint surgery. British volume. Aug 1970;52(3):524-527.

142. Mayerhoefer ME, Breitenseher MJ, Wurnig C, Roposch A. Shoulder impingement: relationship of clinical symptoms and imaging criteria. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine. Mar 2009;19(2):83-89.

143. Viskontas DG, MacDermid JC, Drosdowech DS, Garvin GJ, Romano WM, Faber KJ. Reliability and comparison of acromion assessment techniques on X-ray and magnetic resonance imaging (reliability of acromion assessment techniques). Canadian Association of Radiologists journal = Journal l’Association canadienne des radiologistes. Oct 2005;56(4):238-244.

144. Banas MP, Miller RJ, Totterman S. Relationship between the lateral acromion angle and rotator cuff disease. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.].

Nov-Dec 1995;4(6):454-461.

145. MacGillivray JD, Fealy S, Potter HG, O’Brien SJ. Multiplanar analysis of acromion morphology. Am J Sports Med. Nov-Dec 1998;26(6):836-840.

146. Day BH, Govindasamy N, Patnaik R. Corticosteroid injections in the treatment of tennis elbow. The Practitioner. Mar 1978;220(1317):459-462.

147. Hay EM, Paterson SM, Lewis M, Hosie G, Croft P. Pragmatic randomised controlled trial of local corticosteroid injection and naproxen for treatment of lateral epicondylitis of elbow in primary care.

BMJ. Oct 9 1999;319(7215):964-968.

148. Smidt N, Assendelft WJ, van der Windt DA, Hay EM, Buchbinder R, Bouter LM. Corticosteroid injections for lateral epicondylitis: a systematic review. Pain. Mar 2002;96(1-2):23-40.

149. Arroll B, Goodyear-Smith F. Corticosteroid injections for painful shoulder: a meta-analysis. The British journal of general practice : the journal of the Royal College of General Practitioners. Mar 2005;55(512):224228.

150. Naredo E, Cabero F, Beneyto P, et al. A randomized comparative study of short term response to blind injection versus sonographic-guided injection of local corticosteroids in patients with painful shoulder. The Journal of rheumatology. Feb 2004;31(2):308-314.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 287

151. Chen MJ, Lew HL, Hsu TC, et al. Ultrasound-guided shoulder injections in the treatment of subacromial bursitis. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists.

Jan 2006;85(1):31-35.

152. Mei-Dan O, Carmont MR. The role of platelet-rich plasma in rotator cuff repair. Sports medicine and arthroscopy review. Sep 2011;19(3):244-250.

153. de Vos RJ, van Veldhoven PL, Moen MH, Weir A, Tol JL, Maffulli N. Autologous growth factor injections in chronic tendinopathy: a systematic review. British medical bulletin. 2010;95:63-77.

154. Schnabel LV, Mohammed HO, Miller BJ, et al.

Platelet rich plasma (PRP) enhances anabolic gene expression patterns in flexor digitorum superficialis tendons. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. Feb 2007;25(2):230-240.

155. Sanchez M, Anitua E, Azofra J, Andia I, Padilla S, Mujika I. Comparison of surgically repaired Achilles tendon tears using platelet-rich fibrin matrices. Am J Sports Med. Feb 2007;35(2):245-251.

156. De Mos M, Van der Windt A, Jahr H, et al. Can platelet rich plasma enhance tendon repair? A cell culture study. Am J Sports Med. 2008;36:1171–1178.

157. Anitua E, Andia I, Sanchez M, et al. Autologous preparations rich in growth factors promote proliferation and induce VEGF and HGF production by human tendon cells in culture. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. Mar 2005;23(2):281-286.

158. de Mos M, van der Windt A, Jahr H, et al. Can platelet-rich plasma enhance tendon repair? A cell culture study. Am J Sports Med. 2008;36(6):1171-1178.

159. Zhang J, Wang JH. Platelet-rich plasma releasate promotes differentiation of tendon stem cells into active tenocytes. Am J Sports Med. Dec 2010;38(12):2477-2486.

160. Fufa D, Shealy B, Jacobson M, Kevy S, Murray MM. Activation of platelet-rich plasma using soluble type I collagen. Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. Apr 2008;66(4):684-690.

161. Bishop J, Klepps S, Lo IK, Bird J, Gladstone JN, Flatow EL. Cuff integrity after arthroscopic versus open rotator cuff repair: a prospective study. Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]. May-Jun 2006;15(3):290-299.

162. Bjornsson HC, Norlin R, Johansson K, Adolfsson LE. The influence of age, delay of repair, and tendon involvement in acute rotator cuff tears: structural

and clinical outcomes after repair of 42 shoulders.

Acta orthopaedica. Apr 2011;82(2):187-192.

163. Thomopoulos S, Das R, Birman V, et al.

Fibrocartilage tissue engineering: the role of the stress environment on cell morphology and matrix expression. Tissue engineering. Part A. Apr 2011; 17(7-8):1039-1053.

164. Garofalo R, Cesari E, Vinci E, Castagna A. Role of metalloproteinases in rotator cuff tear. Sports medicine and arthroscopy review. Sep 2011;19(3):207-212.

165. Gulotta LV, Rodeo SA. Growth factors for rotator cuff repair. Clinics in sports medicine. Jan 2009;28(1):13-23.

166. Archambault JM, Jelinsky SA, Lake SP, Hill AA, Glaser DL, Soslowsky LJ. Rat supraspinatus tendon expresses cartilage markers with overuse. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. May 2007;25(5):617-624.

167. Jones GC, Corps AN, Pennington CJ, et al.

Expression profiling of metalloproteinases and tissue inhibitors of metalloproteinases in normal and degenerate human achilles tendon. Arthritis Rheum. Mar 2006;54(3):832-842.

168. Lian O, Scott A, Engebretsen L, Bahr R, Duronio V, Khan K. Excessive apoptosis in patellar tendinopathy in athletes. Am J Sports Med. Apr 2007;35(4):605-611.

169. Longo UG, Franceschi F, Ruzzini L, et al. Light microscopic histology of supraspinatus tendon ruptures. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA. Nov 2007;15(11):1390-1394.

170. Scott A, Cook JL, Hart DA, Walker DC, Duronio V, Khan KM. Tenocyte responses to mechanical loading in vivo: a role for local insulin-like growth factor 1 signaling in early tendinosis in rats. Arthritis Rheum. Mar 2007;56(3):871-881.

171. Scott A, Khan KM, Duronio V. IGF-I activates PKB and prevents anoxic apoptosis in Achilles tendon cells. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. Sep 2005;23(5):1219-1225.

172. Szomor ZL, Appleyard RC, Murrell GA. Overexpression of nitric oxide synthases in tendon overuse. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. Jan 2006;24(1):80-86.

173. Yuan J, Murrell GA, Wei AQ, Wang MX. Apoptosis in rotator cuff tendonopathy. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. Nov 2002;20(6):1372-1379.

The International Journal of Sports Physical Therapy | Volume 9, Number 2 | April 2014 | Page 288

INTERNATIONAL JOURNAL OF SPORTS PHYSICAL THERAPY