CMCC Research Report 2012-2013

Research Report 2012–13 A selection of published research by CMCC faculty

Featured articles include: 14 Lumbar Facet Joint Compressive Injury Induces Lasting Changes in Local Structure, Nociceptive Scores, and Inflammatory Mediators in a Novel Rat Model Henry JL, Yashpal K, Vernon H, Kim J, Im H-J 33 The Association Between Workers’ Compensation Claims Involving Neck Pain and Future Health Care Utilization: A Population-Based Cohort Study Côté P, Yang X, Kristman V, Hogg-Johnson S, Van Eerd D, Rezai M, Vidmar M 47 Changes in Primary Care Physician’s Management of Low Back Pain in a Model of Interprofessional Collaborative Care: an Uncontrolled Before-After Study Mior S, Gamble B, Barnsley J, Côté P, Côté E

Canadian Memorial Chiropractic College

Our Mission An academic institution recognised for creating leaders in spinal health

Our Vision Deliver world class chiropractic education, research and patient care

CMCC is dedicated to pursuing innovation in education, research and patient care. In this way, the institution effectively prepares its students to become tomorrow’s leaders in spinal health.

CMCC’s achievements this year demonstrate the success of this approach in paving the way toward increased collaboration with other health care professions, and helping to define the profession within the changing Canadian health care landscape.

CMCC Research Report 2012–13 A selection of published research by CMCC faculty

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Message from the President and the Dean

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Compressive Force Magnitude and Intervertebral Joint Flexion/ Extension Angle Influence Shear Failure Force Magnitude in the Porcine Cervical Spine Howarth SJ, Callaghan JP

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Cerebral Perfusion in Patients with Chronic Neck and Upper Back Pain: Preliminary Observations Bakhtadze MA, Vernon H, Karalkin AV, Pasha SP, Tomashevskiy IO, Soave D The Association Between a Lifetime History of a Work-Related Neck Injury and Future Neck Pain: A Population Based Cohort Study Nolet PS, Côté P, Cassidy JD, Carroll LJ Elevated Production of Inflammatory Mediators Including Nociceptive Chemokines in Patients With Neck Pain: A CrossSectional Evaluation Teodorczyk-Injeyan JA, Injeyan HS, McGregor M, Triano JJ, Woodhouse L

10 The Relationship Between Self-Rated Disability, Fear-Avoidance Beliefs, and Nonorganic Signs in Patients with Chronic Whiplash-Associated Disorder Vernon H, Guerriero R, Soave D, Kavanaugh S, Puhl A, Reinhart C 11 Prognosis of Patients with Whiplash-Associated Disorders Consulting Physiotherapy: Development of a Predictive Model for Recovery Bohman T, Côté P, Boyle E, Cassidy JD, Carroll LJ, Skillgate E 12 Comparison of Force Development Strategies of Spinal Manipulation Used for Thoracic Pain Cambridge EDJ, Triano JJ, Ross JK, Abbott MS 13 Interprofessional Collaboration and Turf Wars. How Prevalent are Hidden Attitudes?

Chung CL, McGregor M, Manga J, Michailidis C, Stavros D, Woodhouse LJ 14 Lumbar Facet Joint Compressive Injury Induces Lasting Changes in Local Structure, Nociceptive Scores, and Inflammatory Mediators in a Novel Rat Model Henry JL, Yashpal K, Vernon H, Kim J, Im HJ 26 Postural Influence on the Neutral Zone of the Porcine Cervical Spine Under Anterior–Posterior Shear Load Howarth SJ, Gallagher KM, Callaghan JP 26 Manikin-Based Clinical Simulation in Chiropractic Education McGregor M, Giuliano D 27 The Association Between Self-Reported Cardiovascular Disorders and Troublesome Neck Pain: A Population-Based Cohort Study Nolet PS, Côté P, Cassidy JD, Carroll LJ 28 Short-Term Effects of Manipulation to the Upper Thoracic Spine of Asymptomatic Subjects on Plasma Concentrations of Epinephrine and Norepinephrine — A Randomized and Controlled Observational Study Puhl A, Injeyan HS 28 Connective Tissue Infiltration and Subcutaneous Fat in Fascioscapulohumeral Muscular Dystrophy-Affected Biceps Brachii Muscle Sovak G, Triano JJ, Soave D, Tran S, Johnston L, Edwards M

29 Biomechanics – Review of Approaches for Performance Training in Spinal Manipulation Triano JJ, Descarreaux M, Dugas C 30 Validation of a Novel Sham Cervical Manipulation Procedure Vernon HT, Triano JJ, Ross JK, Tran SK, Soave DM, Dinulos MD 31 A Diachronic Study of the Language of Chiropractic Budgell BS, Kwong A, Millar N 31 The Language of Integrative Medicine Budgell BS 32 Coping and Recovery in Whiplash-Associated Disorders: Early use of Passive Coping Strategies is Associated With Slower Recovery of Neck Pain and Pain-Related Disability Carroll LJ, Ferrari R, Cassidy JD, Côté P 33 The Association Between Workers’ Compensation Claims Involving Neck Pain and Future Health Care Utilization: A Population-Based Cohort Study Côté P, Yang X, Kristman V, Hogg-Johnson S, Van Eerd D, Rezai M, Vidmar M 43 Assessing Bias in Studies of Prognostic Factors Hayden J, Cartwright JL, van der Windt DA, Côté P, Bombardier C 43 Towards Establishing an Occupational Threshold for Cumulative Shear Force in the Vertebral Joint — An In Vitro Evaluation of a Risk Factor for Spondylolytic Fractures Using Porcine Specimens Howarth SJ, Callaghan JP 44 Development of an Equation for Calculating Vertebral Shear Failure Tolerance Without Destructive Mechanical Testing Using Iterative Linear Regression Howarth SJ, Giangregorio LM, Callaghan JP 45 Does Prolonged Seated Deskwork Alter the Lumbar Flexion Relaxation Phenomenon?

Howarth SJ, Lee JGB, Glisic D, Beach TAC 46 Viscoelastic Creep Induced by Repetitive Spine Flexion and its Relationship to Dynamic Spine Stability Howarth SJ, Kingston DC, Brown SH, Graham RB 47 Changes in Primary Care Physician’s Management of Low Back Pain in a Model of Interprofessional Collaborative Care: An Uncontrolled Before-After Study Mior S, Gamble B, Barnsley J, Côté P, Côté E 54 Pain-Related Work Interference is a Key Factor in a Worker/Workplace Model of Work Absence Duration Due to Musculoskeletal Conditions in Canadian Nurses Murray E, Mustard C, Franche RL, Ibrahim S, Smith P, Carnide N, Gibson J, Koehoorn M, Côté P, Guzman J 55 Self-Rated Disability, Fear-Avoidance Beliefs, Non-Organic Pain Behaviors are Important Mediators of Ranges of Active Motion in Chronic Whiplash Patients Vernon H, Guerriero R, Kavanaugh S, Soave D, Puhl A 56 Assessing the Attitudes, Knowledge and Perspectives of Medical Students to Chiropractic Wong JJ, Soave D, Di Loreto L, Kara A, Yu K, Mattia A, Weyman K, Kopansky-Giles D 57 Conference Proceedings 2012-13

CMCC Research Report 2012–2013

Introduction

Message from the President and the Dean

We are pleased to provide you with the 2012-2013 Research Report, reflective of a growing body of research undertaken by CMCC faculty.

Many of the scientists within the Division of Research are focused on methods to reduce the burden of disease affecting the musculoskeletal system, particularly of the spine and related disorders. Working independently, and through collaborations with counterparts at the University of Ontario Institute of Technology, (UOIT) the University of Toronto, the University of Alberta, and other world class institutions, CMCC researchers have sought ways to improve patient care by assessing work environments, and improving the understanding of chiropractic treatment and its role in health care delivery.

During this period, CMCC welcomed the addition of the UOIT-CMCC Centre for the Study of Disability Prevention and Rehabilitation to campus. Under the direction of Dr. Pierre Côté, the centre increases the number of on-campus research centres to three and offers an opportunity for increased collaboration and scientific exchange between our institutions. The official opening was celebrated in November 2012 with a ribbon cutting ceremony attended by the Honourable Deb Matthews, Minister of Health and Long-Term Care.

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In collaboration with other academic institutions, industry and government agencies, the centre examines questions about the prevention and management of chronic conditions and is dedicated to understanding and preventing musculoskeletal disability on a level that involves not only chiropractors, but physical therapists, psychologists, orthopaedic surgeons and general practitioners. Côté‘s research will define best practices for the prevention and rehabilitation of disability and contribute to policy development through knowledge transfer and exchange.

Resources for the centre include a $2.8 million grant from the Ministry of Finance, Financial Services Commission of Ontario, to develop a Minor Injury Treatment Protocol.

Through its three research centres, CMCC has presented and published over 100 articles across an array of journals covering clinical sciences, education, pain and disability, sports, biomechanics and ergonomics, and interprofessional collaboration. The global community has recognised these efforts and in the past 24 months alone, 14 awards and honours were presented to CMCC researchers, students and graduates.

The promise of more groundbreaking research has been made possible through the successful application for a grant through the US National Institutes of Health (NIH)

A selection of published research by CMCC faculty

in support of a study of spinal manipulation. The grant which is just under $1 million is the highest level of grant awarded by the NIH. Led by Drs. Howard Vernon, John J. Triano and Tony Tibbles, the study aims to establish a manipulation control to provide a baseline against which treatment outcomes may be measured. Results from this research could improve the rigour of future studies by better defining and controlling study variables and demonstrate the benefits of chiropractic care for a variety of conditions to inform patient care.

In addition to this achievement, CMCC researchers have accelerated and expanded efforts to seek funding by reaching out to funders from all areas including the Canadian and US governments, foundations and corporate parties. This activity has been instrumental in raising awareness with organizations such as the WSIB and WCB

Jean A. Moss, DC, MBA President

Manitoba, the Canadian Dental Health Association and firefighters across the greater Toronto area where further funding opportunities may exist in the future.

All of this is made possible thanks to the contributions of CMCC members and donors and the many funding agencies that support this work.

This report contains a selection of the papers and abstracts published by CMCC faculty in 2012-13 and reflects the depth and breadth of CMCC’s research in addition to its collaborative efforts which are shaping the future of chiropractic care.

We hope you will find it an informative cross section of the work accomplished this year and that it will give you a sense of its potential.

John J. Triano, DC, PhD Dean, Graduate Education & Research Programs

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CMCC Research Report 2012–2013

CMCC Funding Contributors and Collaborators CMCC is grateful for the contributions of collaborating researchers who have partnered with us to advance scientific understanding in areas such as clinical sciences and practice, professional jurisdiction, interprofessional health dynamics, mechanobiology and spine stability among others.

CMCC is also thankful to the following agencies and institutions who have provided funding in support of ongoing research projects and personnel.

• Canadian Institutes of Health Research • National Institutes of Health

• McMaster University

• Ministry of Health and Long-Term Care

• National University of Health Sciences

• Higher Education Quality Council of Ontario

• University of Alberta

• Workplace Safety & Insurance Board Ontario

• University of Guelph

• Workers Compensation Board of Manitoba

• University of Toronto • University of Ontario Institute of Technology • University of Waterloo

Research Activity Grant Submissions By Funder

Corporate

13%

0%

Private Federal Government

23%

US Government

3% 57%

3% Provincial Government

Foundation

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A selection of published research by CMCC faculty

Grant Success 30 25 20 Total of grants where final status known

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Total grants awarded 10 5 0 2008 - 09 2009 -10 2010 -11 2011 - 12 2012 - 13

Faculty Productivity 2007-2013 70 60 50 40

Publications

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Presentations

20 10 0 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 5

CMCC Research Report 2012–2013

CMCC Research Infrastructure Research Ethics Board

President

Animal Care Committee

Dean, Graduate Education & Research

Administrative Coordinator

Research Methodologist

UOIT-CMCC Centre for the Study of Disability Prevention and Rehabilitation

Centre for Interprofessional Health Care Dynamics

Director

Coordinator, Integrated Care and Care Research

Director, Neurophysiology Laboratory

Research Chair, Mechanobiology

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Clinical Research Coordinator

Laboratory Technician

Lab Technician, Biomechanics

Disability Prevention & Rehabilitation 6

Office of Research Administration

Health Policy & Resources

Clinics

Centre for Mechanobiology

Health, Wellness, Injury & Repair

A selection of published research by CMCC faculty

Mechanobiology, Injury and Health

Compressive Force Magnitude and Intervertebral Joint Flexion/Extension Angle Influence Shear Failure Force Magnitude in the Porcine Cervical Spine Howarth SJ1, Callaghan JP 2 1

Canadian Memorial Chiropractic College, 2 University of Waterloo

Abstract Despite the findings that peak anterior shear load is highly correlated with low-back pain reporting, very little research has been conducted to determine how vertebral shear injury potential is influenced. The current study quantified the combined effects of vertebral joint compression and flexion/extension postural deviation from neutral on ultimate shear failure.

Ninety-six porcine cervical specimens (48C3–C4, 48C5–C6) were tested. Each specimen was randomly assigned to one of twelve combinations of compressive force (15%, 30%, 45%, or 60% of predicted compressive failure force) and flexion/extension postural deviation (extended, neutral, or flexed). Vertebral joint shear failure was induced by applying posterior shear displacement of the caudal vertebra at a constant rate of 0.15 mm/s. Throughout shear failure tests, vertebral joint kinematics were measured using an optoelectronic camera and a series of infrared light emitting diodes while shear force was measured from load cells rigidly interfaced in series with linear actuators that applied the shear displacement. Measurements of shear stiffness, ultimate force, displacement, and energy stored were made from the force–displacement data. Compressive force

and postural deviation demonstrated main effects without a statistically significant interaction for any of the measurements.

Shear failure force increased by 11.1% for each 15% increment in compressive force (p<0.05). Postural deviation from neutral impacted ultimate shear failure force by a 12.8% increase with extension (p<0.05) and a 13.2% decrease with flexion (p<0.05).

Displacement at ultimate failure was not significantly altered by either compressive force or postural deviation. These results demonstrate that shear failure force may be governed by changes in facet articulation, either by postural deviation or by reducing vertebral joint height through compression that alter the moment arm length between the center of facet contact pressure and the pars interarticularis location. However, objective evidence of this alteration currently does not exist. Both compression and flexion/ extension postural deviation should be equally considered while assessing shear injury potential.

Originally published in the Journal of Biomechanics, 2012 Feb 2;45(3):484-90. doi: 10.1016/j.jbiomech.2011.11.051.

Epub 2011 Dec 21. Reprinted with permission from Elsevier.

Clinical Sciences

Cerebral Perfusion in Patients with Chronic Neck and Upper Back Pain: Preliminary Observations Bakhtadze MA1, Vernon H2 , Karalkin AV 3, Pasha SP4, Tomashevskiy IO5, Soave D2 1 5

Center for Manual Therapy, 2 Canadian Memorial Chiropractic College, 3 The 1st City Clinical Hospital, 4 1st Moscow State Medical University, Semashko Central Clinical Hospital

Abstract Objective The purpose of this study was to determine the correlation between cerebral perfusion levels, Neck Disability Index (NDI) scores, and spinal joint fixations in patients with neck pain.

Methods Forty-five adult patients (29 were female) with chronic neck/upper thoracic pain during exacerbation were studied. The subjects were grouped according to NDI

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CMCC Research Report 2012–2013

scores: mild, moderate, and severe. The number of painful/ blocked segments in the cervical and upper thoracic spine and costovertebral joints, pain intensity using the visual analog scale, and regional cerebral blood flow of the brain using single-photon emission computed tomography (SPECT) were obtained. The SPECT was analyzed semiquantitatively. Analysis of variance tests were conducted on total SPECT scores in each of the NDI groups (P < .05). Univariate correlations were obtained between blockage, pain, and SPECT scores, as well as age and duration. A multivariate analysis was then conducted.

Results Group 1 (mild) consisted of 14 patients. Cerebral perfusion measured by SPECT was normal in all 8 brain regions.

Group 2 (moderate) consisted of 16 patients. In this group, a decrease in cerebral perfusion was observed (range, 20%35%), predominantly in the parietal and frontal zones. Group 3 (severe) consisted of 15 patients. In this group, the decrease

in cerebral perfusion observed was from 30% to 45%, again predominantly in the parietal and frontal zones. A significant difference was found between NDI groups (“moderate” and “severe” showed significantly greater hypoperfusion than “mild”). Total blockage score correlated with SPECT scores at r = 0.47, P = .001. In a multivariate analysis, NDI scores contributed 39% of the variance of SPECT scores.

Conclusion In this group of patients with neck and/or upper back pain, NDI scores strongly predicted cerebral hypoperfusion.

Spinal joint dysfunction may be involved via hyperactivity in the regional sympathetic nervous system.

Originally published in the Journal of Manipulative and Physiological Therapeutics, 2012 Mar-Apr;35(3):209-15. doi: 10.1016/j.jmpt.2012.01.012. Epub 2012 Feb 17. Reprinted with permission from Elsevier.

Mechanobiology, Injury and Health

The Association Between a Lifetime History of a WorkRelated Neck Injury and Future Neck Pain: A Population Based Cohort Study Nolet PS1, Côté P1, 2, 3 , Cassidy JD2, 3 , Carroll LJ4 1

Canadian Memorial Chiropractic College, 2 University of Toronto, 3 Toronto Western Hospital, 4 University of Alberta

Abstract Objective The purpose of this study was to investigate the association between a lifetime history of a work-related neck injury and the development of troublesome neck pain in the general population.

Methods We formed a cohort of randomly sampled Saskatchewan adults with no or mild neck pain in September 1995. At baseline, participants were asked if they had ever injured their neck at work. Six and 12 months later, participants were asked if they had troublesome neck pain defined as grades II to IV on the Chronic Pain Grade Questionnaire.

Multivariable Cox regression was used to estimate the association between a lifetime history of work-related neck injury and the onset of troublesome neck pain while controlling for age and sex.

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Results Our cohort included 866 individuals at risk for developing troublesome neck pain. Of those, 73.8% (639/866) were followed up at 6 months, and 63.0% (546/866), at 1 year. We found a positive association between a history of a work-related neck injury and the onset of troublesome neck pain (age- and sex-adjusted hazard rate ratio [HRR], 2.4; 95% confidence interval, 1.3-4.7).

Conclusion Our analysis suggests that a lifetime history of workrelated neck injury is associated with an increased risk of troublesome neck pain. Occupational neck injuries can lead to recurrent episodes of neck pain.

Originally published in the Journal of Manipulative and Physiological Therapeutics, 2011 Jul-Aug;34(6):348-55. doi: 10.1016/j.jmpt.2011.06.006.Reprinted with permission from Elsevier.

A selection of published research by CMCC faculty

Basic Sciences

Elevated Production of Inflammatory Mediators Including Nociceptive Chemokines in Patients With Neck Pain: A Cross-Sectional Evaluation Teodorczyk-Injeyan JA1, Injeyan HS1, McGregor M1 , Triano JJ1, 2 , Woodhouse L 2 1

Canadian Memorial Chiropractic College, 2 McMaster University

Abstract Objective This study investigated whether the production of inflammatory mediators and chemotactic cytokines (chemokines) is altered in patients with chronic and recurrent neck pain (NP).

Methods Cross-sectional data evaluating blood and serum samples were obtained from 27 NP patients and 13 asymptomatic (control) subjects recruited from a chiropractic outpatient clinic. Cell cultures were activated by lipopolysaccharide (LPS) and phytoheamagglutinin for 24 to 48 hours. The levels of tumor necrosis factor α (TNF-α), monocyte chemotactic protein 1, also known as CCL2 (CCL2/MCP-1), and macrophage inflammatory protein 1α or CCL3 (CCL3/MIP-1α) were determined by specific immunoassays. Serum levels of nitric oxide metabolites were evaluated simultaneously, in vanadium III–reduced samples, by Griess reaction.

Results Low levels of constitutive (spontaneous) TNF-α production were present in 7 of the 27 cultures from patients with NP.

Both LPS-induced TNF-α production and inducer (LPS/ phytoheamagglutin)-stimulated production of CCL2 were significantly elevated (P = .00) in patients compared with controls. In patients, the constitutive synthesis of CCL3 occurred significantly more frequently (P = .00) and ranged from 30 to more than 2000 pg/mL. Finally, serum levels of nitric oxide were significantly elevated (P = .00) in NP patients.

Conclusions Production of inflammatory mediators was consistently elevated in NP patients in this study, both in vitro and in vivo, and activation of inflammatory pathways was accompanied by up-regulation of CC chemokine synthesis.

This suggests that, in NP patients, CC chemokines may be involved in regulation of local inflammatory response through recruitment of immune cells to the inflamed tissue and exert pronociceptive effects.

Originally published in the Journal of Manipulative and Physiological Therapeutics, 2011 Oct;34(8):498-505. doi: 10.1016/j.jmpt.2011.08.010. Reprinted with permission from Elsevier.

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CMCC Research Report 2012–2013

Clinical Sciences

The Relationship Between Self-Rated Disability, FearAvoidance Beliefs, and Nonorganic Signs in Patients with Chronic Whiplash-Associated Disorder Vernon H1, Guerriero R1, Soave D1, Kavanaugh S2, Puhl A1, Reinhart C1 1

Canadian Memorial Chiropractic College, 2 Private Practice

Abstract Objectives The purpose of this study was to determine the role of standard and novel (cervical) nonorganic signs in patients with chronic whiplash-associated disorder (WAD).

Methods Chronic WAD I to III patients (>3 months) were recruited from private chiropractic practice in Canada. Subjects completed a Neck Disability Index (NDI), Tampa Scale for Kinesiophobia (TSK), pain visual analog scale, and pain diagram. Clinical and demographic data were also obtained. Nine standard nonorganic pain behavior tests and 4 novel cervical nonorganic simulation signs (C-NOSS) tests were applied.

Bivariate correlations were obtained with the Pearson correlation coefficient. Items achieving statistical significance on univariate analysis were loaded in a sequential linear regression analysis. Post hoc analyses were conducted with analysis of variance tests of NDI and TSK scores.

Results Ninety-one subjects were investigated (49 males and 42 females), with a mean age of 41.7 (SD, 14.7) years and a mean duration of 9.4 (SD, 11.2) months. Because mean NDI

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scores were 57.5 (SD, 17.8) and mean pain scores were 68.3 (SD, 21.0), this sample represents moderate-to-severe WAD. Fair to moderately strong correlations were obtained between the NDI and the TSK, pain visual analog scale and nonorganic symptoms and signs (NOS-9) and C-NOSS scores, but not with “age,” “sex,” or “duration.” The NOS9 and C-NOSS scores correlated most strongly at 0.70.

A multivariate model accounting for 53% of the variance of the NDI scores (P < .001) was obtained with the TSK, pain severity, and NOS-9 scores. There was no significant correlation between C-NOSS and TSK scores. At least 25% of subjects scored either 5 of 9 or 2 of 4 on the NOS-9 and C-NOSS tests, respectively.

Conclusions Based on the findings of this study, nonorganic signs should be considered in the interpretation of self-rated disability in patients with moderate-to-severe chronic WAD.

Originally published in the Journal of Manipulative and Physiological Therapeutics, 2011 Oct;34(8):506-13. doi: 10.1016/j.jmpt.2011.08.011. Reprinted with permission from Elsevier.

A selection of published research by CMCC faculty

Mechanobiology, Injury and Health

Prognosis of Patients with Whiplash-Associated Disorders Consulting Physiotherapy: Development of a Predictive Model for Recovery Bohman T1, Côté P2,3,4 , Boyle E4,5,6, Cassidy JD2,3,4,5 , Carroll LJ7, Skillgate E1,8 Institute of Environmental Medicine, 2 Canadian Memorial Chiropractic College, 3 University of Ontario Institute of Technology, 4 University of Toronto, 5 Toronto Western Research Institute, 6 University of Southern Denmark, 7University of Alberta, 8 Skandinaviska Naprapathögskolan (Scandinavian College of Naprapathic Manual Medicine) 1

Abstract Background Patients with whiplash-associated disorders (WAD) have a generally favourable prognosis, yet some develop longstanding pain and disability. Predicting who will recover from WAD shortly after a traffic collision is very challenging for health care providers such as physical therapists.

Therefore, we aimed to develop a prediction model for the recovery of WAD in a cohort of patients who consulted physical therapists within six weeks after the injury.

Methods Our cohort included 680 adult patients with WAD who were injured in Saskatchewan, Canada, between 1997 and 1999. All patients had consulted a physical therapist as a result of the injury. Baseline prognostic factors were collected from an injury questionnaire administered by Saskatchewan Government Insurance. The outcome, global self-perceived recovery, was assessed by telephone interviews six weeks, three and six months later. Twenty-five possible baseline prognostic factors were considered in the analyses. A prediction model was built using Cox regression.

The predictive ability of the model was estimated with

concordance statistics (c-index). Internal validity was checked using bootstrapping.

Results Our final prediction model included: age, number of days to reporting the collision, neck pain intensity, low back pain intensity, pain other than neck and back pain, headache before collision and recovery expectations. The model had an acceptable level of predictive ability with a c-index of 0.68 (95% CI: 0.65, 0.71). Internal validation showed that our model was robust and had a good fit.

Conclusions We developed a model predicting recovery from WAD, in a cohort of patients who consulted physical therapists. Our model has adequate predictive ability. However, to be fully incorporated in clinical practice the model needs to be validated in other populations and tested in clinical settings.

Originally published in BMC Musculoskeletal Disorders, 2012 Dec 29;13:264. doi: 10.1186/1471-2474-13-264. Open access article.

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CMCC Research Report 2012–2013

Mechanobiology, Injury and Health

Comparison of Force Development Strategies of Spinal Manipulation Used for Thoracic Pain Cambridge EDJ1, Triano JJ2, 3, Ross JK 2, Abbott MS2 1

University of Waterloo, 2 Canadian Memorial Chiropractic College, 3 McMaster University

Abstract Introduction To date, there is a paucity of comparative analysis of manual therapeutic procedures for the treatment of pain in the same spinal region. This paper examines the cross correlation of force-time histories across three distinct strategies of force production for the same thoracic spine procedure. Secondary analysis includes examination of the characteristics that account for potential differences.

Methods A homogeneous sample of 21 male volunteers and three clinicians were selected as a convenience sample. The forcetime histories were recorded using a table mounted force plate (AMTI model number OR6-7-2000, London, ON), and crosscorrelation analysis was applied by strategy type, for analysis between group data. Secondary parameters included: peak force, preload force, slope of the thrust, instantaneous loading rate and thrust duration, of the total force magnitude.

Results Primary results indicate strong correlations among all

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strategies but with notably different cross-correlation coefficients (0.894 ≤ r ≤ 0.946) based on individual comparisons.

Classical descriptive components of the force-time curves (e.g. preload, peak force, slope) for each strategy group were examined. Significant differences in the raw data were noted on slope and loading rate (adjusted P < 0.01). One strategy of force development was significantly different from the others in four of the five characteristics. The effects of clinician stature were evaluated by normalizing force to body mass.

Conclusion Quantitative biomechanical differences in procedures may be responsible for differences in outcomes based on the method of treatment selected. This data set begins a basis for translational research to assist in identifying populations of thoracic spine pain patients for whom one procedure or other may be more effective.

Originally published in Manual Therapy, 2012 Jun;17(3):2415. doi: 10.1016/j.math.2012.02.003. Epub 2012 Mar 2.

Reprinted with permission from Elsevier.

A selection of published research by CMCC faculty

â&#x20AC;&#x201A; Interprofessional and Educational

Interprofessional Collaboration and Turf Wars. How Prevalent are Hidden Attitudes?

Chung CL1, McGregor M1, Manga J2, Michailidis C2, Stavros D2, Woodhouse LJ3 1

Canadian Memorial Chiropractic College, 2 Private Practice. 3 University of Alberta

Abstract Purpose: Interprofessional collaboration in health care is believed to enhance patient outcomes. However, where professions have overlapping scopes of practice (eg, chiropractors and physical therapists), "turf wars" can hinder effective collaboration. Deep-rooted beliefs, identified as implicit attitudes, provide a potential explanation. Even with positive explicit attitudes toward a social group, negative stereotypes may be influential. Previous studies on interprofessional attitudes have mostly used qualitative research methodologies. This study used quantitative methods to evaluate explicit and implicit attitudes of physical therapy students toward chiropractic.

Methods: A paper-and-pencil instrument was developed and administered to 49 individuals (students and faculty) associated with a Canadian University master's entrylevel physical therapy program after approval by the

Research Ethics Board. The instrument evaluated explicit and implicit attitudes toward the chiropractic profession.

Implicit attitudes were determined by comparing response times of chiropractic paired with positive versus negative descriptors.

Results: Mean time to complete a word association task was significantly longer (t = 4.75, p =.00) when chiropractic was associated with positive rather than negative words. Explicit and implicit attitudes were not correlated (r = 0.13, p =.38).

Conclusions: While little explicit bias existed, individuals associated with a master's entry-level physical therapy program appeared to have a significant negative implicit bias toward chiropractic.

Originally published in the Journal of Chiropractic Education, 2012 Spring;26(1):32-9. Reprinted with permission.

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CMCC Research Report 2012–2013

Basic Sciences

Lumbar Facet Joint Compressive Injury Induces Lasting Changes in Local Structure, Nociceptive Scores, and Inflammatory Mediators in a Novel Rat Model Henry JL1, Yashpal K1, Vernon H2 , Kim J3, Im HJ3 1

McMaster University, 2 Canadian Memorial Chiropractic College, 3 Rush University Medical Center

Abstract Objective: To develop a novel animal model of persisting lumbar facet joint pain.

Methods: Sprague Dawley rats were anaesthetized and the right lumbar (L5/L6) facet joint was exposed and compressed to ~1mm with modified clamps applied for three minutes; sham-operated and naïve animals were used as control groups. After five days, animals were tested for hind-paw sensitivity using von Frey filaments and axial deep tissue sensitivity by algometer on assigned days up to 28 days. Animals were sacrificed at selected times for histological and biochemical analysis.

Results: Histological sections revealed site-specific loss of cartilage in model animals only. Tactile hypersensitivity was observed for the ipsi- and contralateral paws lasting 28 days. The threshold at which deep tissue pressure just elicited vocalization was obtained at three lumbar levels; sensitivity at L1 > L3/4 > L6.

Biochemical analyses revealed increases in proinflammatory cytokines, especially TNF-α, IL-1α, and IL-1β.

Conclusions: These data suggest that compression of a facet joint induces a novel model of local cartilage loss accompanied by increased sensitivity to mechanical stimuli and by increases in inflammatory mediators.

This new model may be useful for studies on mechanisms and treatment of lumbar facet joint pain and osteoarthritis.

1. Introduction Low back pain is ubiquitous in Western society [1–3]. Its lifetime prevalence is generally accepted to be around 80% and is estimated to be one of the most costly of all medical conditions [1, 4, 5]. The majority of low back pain cases are considered to be nonspecific, with a mechanical origin [2, 6–8]. One of the structures of the spinal motion segment that has been implicated in mechanical low back pain is the lumbar facet joint; however, the contribution of facet joints to low back pain is still controversial [9–11]. Facet joints participate in load bearing in the lumbar spine during spinal motions and compressions [12–16]; they are well innervated with nociceptors [17–26]; low back pain can be provoked in experimental conditions by irritation of the lumbar facet joints [27–29]. Anesthetic blockade can identify a contribution from facet joints in 15–67% of back pain cases [9, 11, 30–35]; neurotomy procedures can relieve chronic facet joint pain [36–39].

The human clinical studies cited above have major limitations with respect to investigating the underlying mechanisms

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of low back pain. While numerous animal models exist to investigate major spinal disorders [40–45], few animal models of lumbar facet joint injury exist [46–51]. To address the significant gaps in knowledge, we undertook to develop a rat model of mechanically induced lumbar facet joint injury.

2. Materials and Methods All experimental procedures were reviewed and approved by the McMaster University Animal Review Ethics Board, and animals were cared for and used according to the Guide to the Care and Use of Laboratory Animals of the Canadian Council on Animal Care, Volumes 1 and 2.

2.1 Model Induction. Male Sprague Dawley rats (225–250, from Charles River Inc., St Constant, QC, Canada) were anesthetized with a combination of ketamine (5 mg/100 g), xylazine (0.5 mg/100 g), and aceptomazine (0.1 mg/100 g), i.p. A midline incision was made and the fascia along the right side of the supraspinous ligament was scraped by blunt dissection. The

Vernon H et al

multifidus muscle at the L5 spinous process was similarly resected to expose the L5-L6 facet joint capsule. Subsequently the L5/6 facet joint was exposed unilaterally on the right side.

In model animals (n = 6), the joint was compressed to ~1mm with modified clamps applied for three minutes (average force = 400 grams); sham surgery animals (n = 6) underwent exposure of the joint without application of the clamp. The muscle was then sutured, and the skin closed using suture clips. Antibiotic ointment (Nitrofurazone 0.2%) was applied over the wound, and 0.03ml of the antibiotic Tribrissen 24% (trimethoprimsulfadiazine) was injected subcutaneously.

Animals were placed under a heating lamp until they recovered from the anaesthetic and then returned to their home cages. Following surgery, animals were allowed to recover and then were tested on days 5, 7, 14, 21, and 28 after surgery as described below. A third group of naïve control animals was also studied (n = 6). Baseline readings were taken before the induction of the model for mechanical sensitivity (von Frey Hair test) and pressure sensitivity (algometry).

2.2 Hind Paw Tactile Sensitivity. Measured by Von Frey Filaments. Von Frey test of plantar sensitivity was included in this study in view of the radiation of pain sensitivity below the knee in some patients with low back pain [52], even to the foot [53]. Further, inflammation in the area of the vertebrae induces increased sensitivity of the foot in animals [54]. Testing consisted of applying an ascending series of fine, calibrated von Frey filaments to the plantar surface of a paw until a fibre is found from which a withdrawal response is observed. The method described previously in Pitcher et al. [55] was used.

The total testing time for each rat usually lasted 35 to 40 min.

Withdrawal thresholds were obtained before surgery and on days 5, 7, 14, 21, and 28 after model induction.

2.3 Pressure Sensitivity of Axial Tissues Measured by Algometer.

For pressure algometry, the rat was acclimatized to a soft cloth and laid on a hard surface with a cylinder under its stomach so the back was slightly lifted. A pressure algometer [56] was then applied over the L6 spinous process and gently pressed until the animal demonstrated discomfort or vocalization. This process was repeated over the L3/4 and L1 spinous processes [23].

These three readings were taken again at 30 and 60 minutes later; this protocol was followed to avoid any additive effect of applying pressure. The data were averaged for each spinal level.

Algometer data were obtained before surgery and on days 7, 14, 21, and 28 after model induction. The controls consisted of naïve (no surgery) and sham surgery groups.

2.4 Histology. Animals in each group were sacrificed for histological examination of lumbar vertebral segments on day 28 after all sensory testing had been completed (n =3 per group).

A selection of published research by CMCC faculty

For histological assessment, the tissue was fixed in 4% formaldehyde, followed by decalcification in EDTA, which was changed every 3 days for 6 weeks. The decalcified facet joints were then cut in the transverse plane, and paraffin embedded. Serial facet joint sections of exact 5 μm thickness were obtained and mounted on histological slides. Sections were taken through xylene and a descending series of alcohol baths to remove the paraffin ready for staining with Safranin-O Fast Green to assess general morphology and the loss of proteoglycan in cartilage ground substance.

The staining solution, 0.1% (w/v) Safranin-O, was prepared in 0.1M sodium acetate buffer at pH 4.6. Staining was carried out for 10 min, and the sections were dehydrated in ethanol solutions and cleared in xylene. Samples were then evaluated for cartilage status, joint surface smoothness, and joint space dimension at day 28. Since histological samples were obtained only on day 28, we graded the cartilage as “healthy” or “completely degenerated.”

2.5 Cytokine Antibody Array and Quantification. Selected animals were sacrificed for biochemical and molecular biology evaluation on days 7, 14, and 28 after model induction. The anesthetized rat was decapitated and the entire rat spinal cord ejected by pressure injection of physiological saline through the L6/S1 vertebral junction. The spinal dorsal horn was dissected under light microscope. The ipsilateral lumbar spinal dorsal horn was immediately wrapped into a piece of chilled-labeled foil and immersed into dry ice and kept frozen until use. These tissues were then subjected to either tissue extraction or total RNA extraction for cytokine antibody array, Western blotting, and real-time two PCR experiments, respectively. Intact naïve rats (N = 3) were included as a control.

Tissues were lysed by homogenization in RIPA buffer (150mM NaCl, 1% NP-40, 0.5% deoxycholate, 0.1% SDS and 50mM Tris, pH 7.5) with protease cocktail inhibitors (Sigma, St. Louis, MO, USA). The total protein concentrations of cell lysates were determined by a bicinchoninic acid protein assay (Pierce, Rockford, IL, USA). An array for cytokine proteins (Cytokine Array, RayBio, Norcross, GA, USA) was used to determine relative alterations in the level of cytokines. Membranes with immobilized antibodies were incubated for 14 h with either 500 μg total protein of the sham control (asymptomatic) or experimental spinal tissues (symptomatic) extracted on day 7 or day 28, followed by biotin-conjugated antibodies, and further incubated with horseradish-peroxidase- (HRP-) conjugated streptavidin. Immunoreactivity was visualized using the ECL system (Amersham Biosciences, Piscataway, NJ, USA) and the Signal Visual Enhancer system (Pierce,

15

CMCC Research Report 2012–2013

Rockford, IL, USA), which magnifies the intensity of the signal.

Densitometric measurement was performed by calculating the integrated density values for each spot (area relative intensity) by using Molecular Imager Versadoc MP 4000 System (Bio-Rad, Hercules CA, USA) and Quantity One- 4.5.0 Basic 1-D Analysis Software (Bio-Rad, Hercules CA, USA).

The positive control signals on each membrane were used in normalization of signal intensity.

2.6 Total RNA Isolation and Reverse Transcription and Real-Time PCR. Lumbar spinal dorsal horns were disrupted and homogenized. Total RNA was isolated from lumbar dorsal horns using the Trizol reagent (Invitrogen, Carlsbad, CA, USA) following the instructions provided by the manufacturer.

Reverse transcription (RT) was carried out with 1`ıg total RNA using ThermoScript TM RT-PCR system (Invitrogen, Carlsbad, CA, USA) for first strand cDNA synthesis. For realtime PCR, cDNA was amplified using MyiQ Real-Time PCR Detection System (Bio-Rad, Hercules CA, USA). Relative mRNA expression was determined using the 2[Δ][Δ]CT method, as detailed by manufacturer (Bio-Rad, Hercules CA, USA). Beta-

actin was used as internal control. The primer sequences and the optimized conditions for use are summarized in Table 1.

2.7 Western Blot Analysis for ERK MAP Kinase Activity.

Tissue lysates from the ipsi- and contralateral dorsal horns of the spinal cords were prepared using homogenizer and modified cell lysis RIPA buffer: 20mM Tris (pH 7.5), 150mM NaCl, 1mM EDTA, 1mMEGTA, 1% Nonidet P-40, 0.25% deoxycholate, 2.5mM sodium pyrophosphate, 1mM glycerol phosphate, 1mMNaVO4, with 2mMphenylmethylsulfonyl fluoride (Sigma, St. Louis, MO, USA). Total protein concentrations of spinal cord tissue lysates were determined by a bicinchoninic acid (BCA) protein assay (Pierce). Equal amount of protein was resolved by 10% SDSPAGE gels and was transferred to nitrocellulose membrane for immunoblot analysis by using phosphospecific anti-ERK antibody (Cell Signaling, Danvers, MA). Nonphosphospecific total anti- ERK antibody (Cell Signaling, Danvers, MA) was used for internal control for normalization of the western blotting analyses. Immunoreactivity was visualized using the ECL system (Amersham) and the Signal Visual Enhancer system (Pierce) which magnifies the signal. All immunoblotting experiments were repeated at least three times.

Table 1 Primer TNF-α

IL-1β

CGRP

Substance P

MMP-2

BDNF

NK-1

NK-2

Galanin

Neuropeptide Y

β-actin

16

Sequences Forward: 5 -TCTGTGCCTCAGCCTCTTCTCATT-3 Reverse: 5 -TTGGGAACTTCTCCTCCTTGTTGG-3 Forward: 5 -TCATCTTTGAAGAAGAGCCCGTCC-3 Reverse: 5 -TGCAGTGCAGCTGTCTAATGGGAA-3 Forward: 5 -TCTAGTGTCACTGCCCAGAAGAGA-3 Reverse: 5 -GGCACAAAGTTGTCCTTCACCACA-3 Forward: 5 -TGGTCAGATCTCTCACAAAGG-3 Reverse: 5 -TGCATTGCGCTTCTTTCATA-3 Forward: 5 -ACCTCTTACAACAGCTGTACCACC-3 Reverse: 5 -TTTCCACCCACAGTGGACATAGCA-3 Forward: 5 -TCCTGGAGAAAGTCCCGGTATCAA-3 Reverse: 5 -TAGTTCGGCATTGCGAGTTCCAGT-3 Forward: 5 -TGGGCAACGTAGTGGTGATA-3 Reverse: 5 -CACGGCTGTCATGGAGTAGA-3 Forward: 5 -CCGAGCACCATTCTGTTTTT-3 Reverse: 5 -GGAGAGTCAACCGGTGTCAT-3 Forward: 5 -TTCCCACCACTGCTCAAGATG-3 Reverse: 5 -TGGCTGACAGGGTTGCAA-3 Forward: 5 -AGATCCAGCCCTGAGACACTGATT-3 Reverse: 5 -TGGAAGGGTCTTCAAGCCTTGTTC-3 Forward: 5 -TGTCACCAACTGGGACGATATGGA-3 Reverse: 5 -AGCACAGGGTGCTCCTCA-3

Tm

Gene No.

60

NM- 012675.3

60

NM- 031512.2

55

NM- 001033956.1

55

NM- 012666.2

60

NM- 031054.2

60

GQ395803.1

60

NM- 012667.2

60

NM- 080768.1

55

NM- 033237.1

55

M15793.1

55

NM- 031144

Vernon H et al

A selection of published research by CMCC faculty

1 mm

1 mm

(a) (b) Figure 1 An axial section of the facet joint from L5/L6 stained with Safranin-O (4 wk post-surgery). (a) Left side: sham control facet joint with exposed after open surgery, and right side: intact side of facet joint. (b) Left side: facet joint L5/L6 with open surgery followed by compression, and right side: intact side of facet joint (20x).

200 μm

(a) Sham control facet joint L5/L6 (right side)

200 μm

(c) Compressed facet joint L5/L6 (right side)

200 μm

(b) Sham control facet joint L5/L6 (left side)

200 μm

(d) Contralateral facet joint L5/L6 (left side)

Figure 2 A larger magnification (100x) to examine structural changes in the facet joint L5/L6. Facet joints with and without compression were stained with Safranin-O (4wk postsurgery) followed by microscopic examination.

2.8 Statistical Analysis. All results are expressed as mean ± SEM. (standard error of mean). Statistical analysis on VF and algometry data was carried out using two-way repeated measures nested ANOVA’s with the factors group and time. Post-hoc comparisons were conducted by evaluation of adjusted P-values using Tukey’s test or Holm’s method, depending on whether the analysis was pair-wise. P < 0.05 was accepted as significant in the ANOVA’s. The evaluation of real-time PCR data was done by one-way ANOVA with a post-hoc Tukey’s test using 2^[∆][∆] Ct values of each sample. A value of P < 0.05 was considered significant.

3. Results 3.1 Histology of Lumbar Facet Joint. In the model group, all samples scored “completely degenerated” while the sham surgery group samples all scored “healthy” cartilage.

Histological examination of articular cartilage in the facet joint on both sides of sham control (left and right) Figures 1(a) and 1(b) and the contralateral joint in the model group

(left) Figures 2(a)–2(d), shows no sign of tissue degeneration at any time. The articular surfaces were smooth and the matrix was densely stained (red) with Safranin-O. In the model group/compressed side, all rats demonstrated severe cartilage degeneration, proteoglycan loss, and structural changes in the ipsilateral facet joint components as reflected by surface irregularities and denudation at week 4.

3.2 Von Frey Test. The animals in the model group (n = 6) showed increased tactile sensitivity not only in the ipsilateral foot but also in the contralateral foot as shown in Figure 3(a).

In the ipsilateral foot, the withdrawal threshold to von Frey filaments had decreased by day 5, and it remained lowered throughout the testing period, as measured on days 7, 14, 21, and 28. The data are shown as mean (±SEM) for each point. The withdrawal threshold of the contralateral foot also decreased, reaching its lowest level on day 14, after which it showed an upward return toward baseline by day 28.

17

CMCC Research Report 2012–2013 Surgery Changes of baseline reading (s) (%)

Changes of baseline reading (s) (%)

Surgery

Days after surgery (a)

Days after surgery (b)

Figure 3 (a) von Frey data comparing tactile threshold between ipsilateral foot (■) with the contralateral foot (□) in animals after facet joint compression on day 5, 7, 14, 21, and 28. (b) Comparison of tactile sensitivity in the three groups: naïve (•; n = 6), sham (▲; n = 6) and model (■; n = 6) animals. The model animals showed a statistically significant difference from the sham and the naïve animals on all test days (P < 0.001).

Figure 3(b) illustrates the tactile sensitivity of the ipsilateral foot in the three animal groups: model (n = 6), sham surgery (n = 6) and naïve group with no surgery (n = 6). The naïve and sham groups remained at normal values on all days with no significant difference. As the figure shows, the model group is significantly different from both naïve and sham surgery groups on all the testing days (P < 0.0001). Post-hoc testing revealed that, at all time points, the model group’s difference from the sham surgery and naïve groups was statistically significant (P values ranged from 0.0096–0.0001).

3.3 Algometer Test. The pressure sensitivity measured by algometer at L1, L3/4, and L6 in model rats (n = 6), sham rats (n = 6), and naïve rats (n = 6) is shown in Figure 4. The data are mean (SEM) for each lumbar position in each group. L6 appears to be the least sensitive site as shown in Figure 4(a).

At L3/4, the model animals showed a significantly increased sensitivity compared to sham animals, but only on days 7 and 28 (P < 0.01). However, compared to naïve animals, the model animals were significantly more sensitive to pressure throughout the testing period (P < 0.01), except for day 21.

The data are shown in Figure 4(b). At L1 model animals exhibited increased sensitivity compared to sham and naïve animals (P < 0.001) throughout the testing period, including days 7, 14, 21, and 28 (Figure 4(c)).

3.4 Cytokine Antibody Array. In the model group, prominent increases in the levels of multiple proinflammatory cytokines and chemokines were observed at day 28 (Figure 5; all results P > 0.05). These cytokines include cytokineinduced neutrophil chemoattractant-3 (CINC3), IL-1α, IL-1β, RANTES, IL-6, IL-17, macrophage inflammatory protein 2α (MIP2α), and TNFα. Also, we observed significant induction of anti-inflammatory cytokines (e.g., IL-3, IL-4, IL-13) at day 28, but not at day 7. IL-1 receptor antagonist (IL-1ra)

18

which can antagonize inflammatory action mediated by IL-1 cytokine family members is highly expressed at day 7 after the facet joint injury and returned to the control level at day 28. Unexpectedly, we observed a robust and sustained induction of tissue inhibitor of metalloproteinase-1 (TIMP-1), a potent inhibitor of matrix metalloproteinases (MMPs), at both Day 7 and Day 28 time points.

3.5 Real-Time PCR Analyses. We further assessed whether cytokine protein levels correspond with changes in mRNA levels within the cellular components of the spinal cord (i.e. glial cells and neurons). We examined IL-1beta and TNFα mRNA as representative painassociated cytokines which are highly upregulated at the protein level in the spinal cord due to facet joint compression-induced pain (Figures 6(a)–6(d)). Real-time PCR results demonstrate that the mRNA level of TNFα is substantially increased at the chronic stages of facet joint injury-induced pain period (P < 0.05, Day 28), but not during earlier stages (day 7 or day 14). As expected, highly upregulated expression of TNFα was observed at the right spinal cord dorsal horn of compressed facet joint, (P < 0.05, day 28) compared to left spinal cord dorsal horn at the same level.

We observed almost identical expression patterns for IL- 1β in the spinal cord. Significantly induced expression of IL-1β at day 28 time point after facet joint injury (P < 0.05) was detected which is not observed during earlier time points (day 7 or day 14). We also observed highly upregulated expression of IL-1β at the right spinal cord dorsal horn of compressed facet joints (P < 0.05, day 28) compared to left spinal cord dorsal horn at the model level. Parallel experiments were performed using spinal samples from controls (surgery and naïve) in which we found no significant differences in the mRNA levels of

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A selection of published research by CMCC faculty

3.5

3

2.5

2.5

2

2

(kg/cm2)

(kg/cm2)

3

3.5 Surgery

1.5

1.5

1

1

0.5

0.5

0

Surgery

0 -7 0 7 14 21 28

-7 0 7 14 21 28

Days after surgery Model Sham Naïve

Days after surgery Model Sham Naïve

(a)

(b)

3.5 3 2.5

Surgery

(kg/cm2)

2 1.5 1 0.5 0

-7 0 7 14 21 28

Days after surgery Model Sham Naïve

(c)

Figure 4 Pressure sensitivity measured by algometer in naïve (n = 6), sham (n = 6) and model (n = 6) rats at lumbar levels 6, 3/4 and 1. (a) At L6, model animals showed a difference in sensitivity only on day 7 compared to either sham or naïve animals (P < 0.05). (b) At L3/4, model animals showed a higher sensitivity compared to sham animals on days 7 and 28 (P < 0.01) and compared to naïve animals on days 7, 14 and 28 (P < 0.01). (c) At L1, model animals showed a higher sensitivity to pressure on all test days compared to sham and naïve animals (P < 0.001).

either TNFα or IL-1β throughout the experimental time course. Notably, these mRNA expression levels are consistent with protein levels detected in cytokine antibody array results (Figure 5).

3.6 ERK MAP Kinase Activity in Dorsal Horn of the Spinal Cords. ERK/MAPK levels in the lumbar spinal dorsal horn (sham control (upper panel) versus experimental group (lower panel): days 7, 14, and 28) are shown in Figure 7. Compared to naïve controls (lanes 1, 2) and sham-surgery controls (upper panel, lanes 3, 4), we observed that the early induction of ERK activation within day 7 reflected by phosphorylation of a 44 kDa MAPK isoform (ERK1/MAPK) in the experimental group (L5/L6 facet joint compressed) (lower panel, lanes 3, 4).

These early inductions of ERK are significantly decreased in a

time-dependent manner (lower panel, lanes 5–8) whereas no change is observed in naïve controls.

4. Discussion The present study demonstrates that a brief compression of the right L5-L6 facet joint in the rat produces a localized intra-articular damage as evidenced by the substantial degradative changes in facet joint cartilage by day 28 as compared to sham surgery and naïve control animals. The histological findings of severe cartilage degeneration at 28 days compare favorably to those of Tachihara et al. [46], who used injection of Complete Freund’s Adjuvant, Kim et al. [51], who used monosodium iodoacetate (MIA) and to those of Yeh et al. [57], who injected collagenase into a single lumbar facet joint.

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CMCC Research Report 2012–2013

Sham versus compressed rat spinal cord DH (right, ipsilateral) fold change from sham in cytokine expression over time

60 50

Fold change

40 30 20 10

VEGF

TNFα

TIMP-1

Thymus

chemokine

MIP2α

Rantes

MIG

MIP1α

LIX

L-selectin

IL-17

IP-10

IL-10

11-13

II-4

IL-6

IL-2

IL-3

IL-1β

IL-1ra

IFN

IL1-α

GM-CSF

slCAM-1

CNTF

Fractaline

CINC3

CINC1

-10

CINC2 a/b

0

Day 7 Day 28

Figure 5 Cytokine array (all P values less than 0.05).

Our model also exhibited pain-related behavioral changes.

For this analysis, we employed one standard test— von Frey hairs for tactile hypersensitivity—as well as one novel test— pressure algometry over the spine. Our finding of sustained ipsilateral hypersensitivity, lasting at least to 28 days, is in contrast to that of Tachihara et al. [46] who reported model versus control differences only up to 7 days. The first week postsurgery and postmodel induction could be considered as a time when such behavioral signs represent reactions primarily to these interventions. It is of great importance, then, that the hypersensitivity induced by mechanical compression of the facet joint in the current model does persist beyond this stage and likely represents a manifestation of sustained nociceptive input from the injured facet joint rather than possible postsurgical input.

These findings are consistent with those of Lee et al.

[58–61] who have demonstrated similar findings of tactile hypersensitivity in the forepaw of a ratmodel of cervical facet joint mechanical injury up to 14 days postmodel induction.

Our finding of bilateral tactile hypersensitivity is novel, and suggests substantial spill-over of nociceptive input to the contralateral dorsal horn [62, 63]. Bilateral hypersensitivity argues against the explanation in Tachihara et al. [46] that their finding of unilateral hypersensitivity was the result of inflammatory exudation anterior to the facet joint irritating the nerve root, thus inducing a radiculopathy.

The algometry data are, to our knowledge, relatively novel within the group of studies of facet joint models. Only Kim et al. [51] have reported using spinal algometry; however, they measured pressure pain threshold at only the lesion site. In the present

20

study, for all test sites, model rats demonstrated significantly greater reductions in local spinal pressure thresholds for all test points, indicating, once again, that mechanical facet compression produces long-lasting changes that would be equivalent to low back “tenderness” in the human circumstance. It is noteworthy that the spinal pressure hypersensitivity also exhibits a spatial spread, whereby the greatest reduction in pressure threshold in model animals was at the L1-L2 vertebral level. This finding could be explained by the fact that the L5-6 facet joint (at least in the rat) has been shown to receive innervation from L2 via afferents which descend from that level in the paravertebral sympathetic trunk [23, 64]. This has been used to explain referred pain to the groin in cases of L5- 6 disc and facet pain [23]. Alternatively, the application of the pressure algometer at the L1-2 level may have resulted in larger bending moments at the L5-6 level with greater irritation of the model lesion.

The biochemical findings suggest that modulation in the expression of proinflammatory cytokines, such as IL- 1β or TNFα, and perhaps combinations of other cytokines, in dorsal horn neurons, is induced by mechanical facet joint compression and persists up to 28 days. Our findings cannot be directly compared to those of Tachihara et al. [46] because they only measured TNFα expression in dorsal root ganglion cells, while we studied dorsal horn cell expression.

Interestingly, they found upregulation in TNFalpha-expressing DRG neurons for only days 1 and 3; no difference was found between model versus controls from days 7–28. In our study, TNF-alpha and IL-1-β expression was largest in DH cells at day 28. Our findings are consistent with those of Lee et al. [65, 66] who demonstrated increased cytokine mRNA levels in the spinal cord of their cervical facet-injured rats.

A selection of published research by CMCC faculty

Sham versus compressed-right side of spinal cord TNFα P < 0.05

8 6 4 2 0

7 14 28 (days)

Relative TNFα gene induction (TNFα/β-actin)

Relative TNFα gene induction (TNFα/β-actin)

Vernon H et al

Left side of spinal cord versus right side of spinal cord TNFα 3 2.5 2 1.5 1 0.5 0

Sham L5/6 facet joint compressed

Left spinal cord (dorsal horn) of L5/6 facet joint compressed Right spinal cord (dorsal horn) of L5/6 facet joint compressed

(a)

(b) Sham versus compressed-right side of spinal cord IL-1β Relative IL-1β gene induction (IL-1β/β-actin)

Relative IL-1β gene induction (IL-1β/β-actin)

Control versus sham versus compressed-right side of spinal cord IL-1β 6

4

2

0

7 14 28 (days) L5/6 facet joint compressed

Control Sham

7 14 28 (days)

(c)

8 6 4 2 0

7 14 28 (days) Sham L5/6 facet joint compressed (d)

Figure 6 (a) Total dorsal horn TNF-alpha RNA. Sham control (gray, open surgery is performed as in the experimental group, but without facet joint compression) and the experimental group (black, open surgery followed by facet joint L5/L6 compression) during a time course (day 7, 14, and 28). Real-time PCR results were normalized by using β-actin as an internal control. (b) Total dorsal horn TNF-alpha RNA. Experimental group in a time course (day 7, 14, and 28), left versus right sides of lumbar spinal dorsal horn. Real-time PCR results were normalized by using β-actin as an internal control. (c) Total dorsal horn IL-1beta RNA. Sham control (gray, open surgery is performed as in the experimental group, but without facet joint compression) and the experimental group (black, open surgery followed by facet joint L5/L6 compression) during a time course (day 7, 14, and 28). Real-time PCR results were normalized by using β-actin as an internal control. (d)Total dorsal horn IL-1beta RNA. Experimental group in a time course (day 7, 14, and 28), left versus right sides of lumbar spinal dorsal horn. Real-time PCR results were normalized by using β-actin as an internal control.

Spinal cord ERK responses are a novel marker for facet pain studies. Mitogen-activated protein kinases (MAPKs), which encompass the three subgroups, ERK, p38, and JNK MAPKs, are important for intracellular signal transduction and play critical roles in regulating neural plasticity and inflammatory responses. In particular, ERK activation in spinal cord dorsal horn neurons by nociceptive activity plays a critical role in central sensitization by regulating the activity of glutamate receptors and potassium channels [67–73].

To our knowledge, this is the first animal model of mechanically induced facet joint pain to demonstrate cartilage degeneration. This is in contrast to prior models which induced an autoimmune reaction in the joint (with CFA [46]), cartilage cell apoptosis with collagenase injection [57], chondrocyte disruption with MIA [51], or pain with surgical incision [49, 50]. In the case of CFA injection, while a more rapid onset of autoimmune-induced inflammatory reaction appears to be induced, with signs of cartilage degeneration appearing within 3 days, significant differences in nociceptive

21

CMCC Research Report 2012–2013

Pain Research and Treatment

L5/6 facet joint compressed

Sham

Right dorsal horn of spinal cord in L5/6 facet joint compressed rat Naive

Day no.7

Day no. 14 Day no. 28

1

3

5

2

4

6

7

8

Phospho-ERK

44 kDa 42 kDa

Total ERK

44 kDa 42 kDa

Phospho-ERK

44 kDa 42 kDa

Total ERK

44 kDa 42 kDa

Early induction of p-ERK

Gradual reduction of p-ERK

Figure 7 Entire rat spinal cords were ejected and lumbar dorsal horns were dissected from intact control (naïve tissue), sham control (upper panel, open surgery is performed as in the experimental group, but without facet joint compression) and the experimental group (lower panel, open surgery followed by facet joint L5/L6 compression) in a time course (day 7, 14, and 28). Tissue lysates of spinal cords were prepared and equal amount of protein (25 μg each) was analyzed for the activation of ERK MAP kinase 1/2 (44 and 42 kDa, resp.) by using phosphospecific anti-ERK1/2 antibody. Nonphosphospecific total anti-ERK antibody was used for internal control for normalization of the western blotting analyses. All immunoblotting experiments were repeated at least three times.

behaviors in model animals are demonstrated for only 7 days postmodel induction. In the work of Yeh et al. [57], findings of cartilage degeneration are evident by day 7; however, no data were presented on nociceptive behaviors.

In the works of Miyagi et al. [49] and Sakuma et al. [50], only nociceptive-related findings were reported with no indications of facet joint arthritic changes. Kim et al. [51] report on nociceptive-related and histological changes but do not report on dorsal horn biomarkers. Our model appears to create significant changes in each of these domains, pain behaviors and mechanisms as well as degenerative joint changes, and it appears to do so in a timeframe that more closely emulates some conditions of low back pain in humans.

here, future studies could aim at larger sample sizes as well as additional time points.

To provide more details on the time course of the endpoints in this study and to examine the correlation between the histological, biochemical, and behavioral changes, we report

This work is supported by National Chiropractic Mutual Insurance Company (J.Henry, K. Yashpal,H. Vernon) 17 and NIH R01AR053220 (H-J. Im).

5. Conclusions The results of this initial study are encouraging and prompt further study on this model. A brief physical trauma to a single facet joint induces important structural and functional changes. The initial biochemical studies confirm that changes occur in mechanisms related to adaptive and maladaptive reactions to brief trauma. The results of this study may provide a basis for future investigation, understanding, and, eventually, treatment of lumbar facet-related pain.

Acknowledgment

References 1. N. Maniadakis and A. Gray, “The economic burden of back pain in the UK,” Pain, vol. 84, no. 1, pp. 95–103, 2000.

2. R. A. Deyo and J. N. Weinstein, “Low back pain,” The New England Journal of Medicine, vol. 344, no. 5, pp. 363–370, 2001.

3. R. A. Deyo, S. K. Mirza, and B. I. Martin, “Back pain prevalence and visit rates: estimates from U.S. national surveys, 2002,” Spine, vol. 31, no. 23, pp. 2724–2727, 2006.

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4. X. Luo, R. Pietrobon, S. X. Sun, G. G. Liu, and L. Hey, “Estimates and patterns of direct health care expenditures among individuals with back pain in the United States,” Spine, vol. 29, no. 1, pp. 79–86, 2004.

5. D. P. Ritzwoller, L. Crounse, S. Shetterly, and D. Rublee, “The association of comorbidities, utilization and costs for patients identified with low back pain,” BMC Musculoskeletal Disorders, vol. 7, article 72, 2006.

Vernon H et al

6. L. Manchikanti, V. Singh, V. Pampati et al., “Evaluation of the relative contributions of various structures in chronic low back pain,” Pain Physician, vol. 4, no. 4, pp.

308–316, 2001.

7. G. Waddell and A. K. Burton, “Concepts of rehabilitation for the management of low back pain,” Best Practice & Research Clinical Rheumatology, vol. 19, no. 4, pp.

655–670, 2005.

8. G. Waddell, “Subgroups within “nonspecific” low back pain,” The Journal of Rheumatology, vol. 32, no. 3, pp.

395–396, 2005.

9. N. Sehgal, R. V. Shah, A. M. McKenzie-Brown, and C. R. Everett, “Diagnostic utility of facet (zygapophysial) joint injections in chronic spinal pain: a systematic review of evidence,” Pain Physician, vol. 8, no. 2, pp.

211–224, 2005.

10. S. P. Cohen and S. N. Raja, “Pathogenesis, diagnosis, and treatment of lumbar zygapophysial (facet) joint pain,” Anesthesiology, vol. 106, no. 3, pp. 591–614, 2007.

11. Manchikanti, S. Pampati, and K. A. Cash, “Making sense of the accuracy of diagnostic lumbar facet joint nerve blocks: an assessment of the implications of 50% relief, 80% relief, single block, or controlled diagnostic blocks,” Pain Physician, vol. 13, no. 2, pp.

133–143, 2010.

12. M. Lorenz, A. Patwardhan, and R. Vanderby Jr., “Loadbearing characteristics of lumbar facets in normal and surgically altered spinal segments,” Spine, vol. 8, no. 2, pp. 122–130, 1983.

13. K. H. Yang and A. I. King, “Mechanism of facet load transmission as a hypothesis for low-back pain,” Spine, vol. 9, no. 6, pp. 557–565, 1984.

14. T. Videman, M. Nurminen, and J. D. G. Troup, “1990 Volvo award in clinical sciences: lumbar spinal pathology in cadaveric material in relation to history of back pain, occupation, and physical loading,” Spine, vol. 15, no. 8, pp.

728–740, 1990.

15. J. J. Triano, “Buckling: a model of subluxatio,” in Foundations of Chiropractic: Subluxation, M. Gatterman, Ed., pp. 283–295, Elsevier Mosby, St Louis, Mo, USA, 2nd edition, 2005.

16. J. S. Little and P. S. Khalsa, “Human lumbar spine creep during cyclic and static flexion: creep rate, biomechanics, and facet joint capsule strain,” Annals of Biomedical Engineering , vol. 33, no. 3, pp. 391– 401, 2005.

17. N. Bogduk and D. M. Long, “The anatomy of the socalled “articular nerves” and their relationship to facet denervation in the treatment of low back pain,” Journal of Neurosurgery, vol. 51, no. 2, pp. 172–177, 1979.

A selection of published research by CMCC faculty

18. N. Bogduk, “The innervation of the lumbar spine,” Spine, vol. 8, no. 3, pp. 286–293, 1983.

19. L. G. F. Giles and J. R. Taylor, “Innervation of lumbar zygapophysial joint synovial folds,” Acta Orthopaedica Scandinavica, vol. 58, no. 1, pp. 43–46, 1987.

20. L. G. F. Giles and J. R. Taylor, “Human zygapophyseal joint capsule and synovial fold innervation,” British Journal of Rheumatology, vol. 26, no. 2, pp. 93–98, 1987.

21. M. Gronblad, J. N.Weinstein, and S. Santavirta, “Immunohistochemical observations on spinal tissue innervation: a review of hypothetical mechanisms of back pain,” Acta Orthopaedica Scandinavica, vol. 62, no.

6, pp. 614–622, 1991.

22. J. M. Cavanaugh, A. C. Ozaktay, H. T. Yamashita, and A. I. King, “Lumbar facet pain: biomechanics, neuroanatomy and neurophysiology,” Journal of Biomechanics, vol. 29, no. 9, pp. 1117–1129, 1996.

23. K. Suseki, Y. Takahashi, K. Takahashi et al., “Innervation of the lumbar facet joints: origins and functions,” Spine, vol. 22, no. 5, pp. 477–485, 1997.

24. R. F. McLain and J. G. Pickar, “Mechanoreceptor endings in human thoracic and lumbar facet joints,” Spine, vol. 23, no. 2, pp. 168–173, 1998.

25. P. Lau, S. Mercer, J. Govind, and N. Bogduk, “The surgical anatomy of lumbar medial branch neurotomy (facet denervation),” Pain Medicine, vol. 5, no. 3, pp. 289–298, 2004.

26. M. Masini, W. S. Paiva, and A. S. Araujo Jr., “Anatomical description of the facet joint innervation and its implication in the treatment of recurrent back pain,” Journal of Neurosurgical Sciences, vol. 49, no. 4, pp.

143–146, 2005.

27. V. Mooney and J. Robertson, “The facet syndrome,” Clinical Orthopaedics and Related Research, vol. 115, pp.

149–156, 1976.

28. I. W. McCall, W. M. Park, and J. P. O’Brien, “Induced pain referral from posterior lumbar elements in normal subjects,” Spine, vol. 4, no. 5, pp. 441–446, 1979.

29. R. Marks, “Distribution of pain provoked from lumbar facet joints and related structures during diagnostic spinal infiltration,” Pain, vol. 39, no. 1, pp. 37–40, 1989.

30. S. J. Dreyer and P. H. Dreyfuss, “Low back pain and the zygapophysial (facet) joints,” Archives of Physical Medicine and Rehabilitation, vol. 77, no. 3, pp. 290–300, 1996.

31. M. Kaplan, P. Dreyfuss, B. Halbrook, and N. Bogduk, “The ability of lumbar medial branch blocks to anesthetize the zygapophysial joint: a physiologic challenge,” Spine, vol.

23, no. 17, pp. 1847–1852, 1998.

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CMCC Research Report 2012–2013

32. L. Manchikanti, V. Pampati, B. Fellows, and C. E. Bakhit, “Prevalence of lumbar facet joint pain in chronic low back pain,” Pain Physician, vol. 2, no. 3, pp. 59–64, 1999.

33. M. Laslett, B. McDonald, C. N. Aprill, H. Tropp, and B. Oberg, “Clinical predictors of screening lumbar zygapophyseal joint blocks: development of clinical prediction rules,” The Spine Journal, vol. 6, no. 4, pp.

370–379, 2006.

34. R. Manchukonda, K. N. Manchikanti, K. A. Cash, V. Pampati, and L. Manchikanti, “Facet joint pain in chronic spinal pain: an evaluation of prevalence and false-positive rate of diagnostic blocks,” Journal of Spinal Disorders & Techniques, vol. 20, no. 7, pp.

539–545, 2007.

35. D. S. Binder and D. E. Nampiaparampil, “The provocative lumbar facet joint,” Current Reviews in Musculoskeletal Medicine, vol. 2, no. 1, pp. 15–24, 2009.

36. G. Mikeladze, R. Espinal, R. Finnegan, J. Routon, and D. Martin, “Pulsed radiofrequency application in treatment of chronic zygapophyseal joint pain,” The Spine Journal, vol. 3, no. 5, pp. 360–362, 2003.

37. R. Lindner, M. E. Sluijter, and W. Schleinzer, “Pulsed radiofrequency treatment of the lumbar medial branch for facet pain: a retrospective analysis,” Pain Medicine, vol. 7, no. 5, pp. 435– 439, 2006.

38. C. Birkenmaier, A. Veihelmann, H. H. Trouillier, J. Hausdorf, and C. von Schulze Pellengahr, “Medial branch blocks versus pericapsular blocks in selecting patients for percutaneous cryodenervation of lumbar facet joints,” Regional Anesthesia and Pain Medicine, vol. 32, no. 1, pp.

27–33, 2007.

39. M. Gofeld, J. Jitendra, and G. Faclier, “Radiofrequency denervation of the lumbar zygapophysial joints: 10-year prospective clinical audit,” Pain Physician, vol. 10, no. 2, pp. 291–300, 2007.

40. J. A. DeLeo and B. A. Winkelstein, “Physiology of chronic spinal pain syndromes: from animal models to biomechanics,” Spine, vol. 27, no. 22, pp. 2526–2537, 2002.

41. K. Singh, K. Masuda, and H. S. An, “Animal models for human disc degeneration,” The Spine Journal, vol. 5, no.

6, supplement, pp. S267–S279, 2005.

42. J. W. Larson 3rd, E. A. Levicoff, L. G. Gilbertson, and J. D. Kang, “Biologic modification of animal models of intervertebral disc degeneration,” The Journal of Bone and Joint Surgery A , vol. 88, no. 2, supplement, pp.

83–87, 2006.

43. J. C. Lotz and J. A. Ulrich, “Innervation, inflammation, and hypermobility may characterize pathologic disc degeneration: review of animal model data,” Journal of Bone and Joint Surgery A , vol. 88, supplement 2, pp.

76–82, 2006.

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44. H. S. An and K. Masuda, “Relevance of in vitro and in vivo models for intervertebral disc degeneration,” Journal of Bone and Joint Surgery A , vol. 88, supplement 2, pp.

88–94, 2006.

45. M. Alini, S. M. Eisenstein, K. Ito et al., “Are animal models useful for studying human disc disorders/degeneration?”

European Spine Journal, vol. 17, no. 1, pp. 2–19, 2008.

46. H. Tachihara, S.-I. Kikuchi, S.-I. Konno, and M. Sekiguchi, “Does facet joint inflammation induce radiculopathy?

An investigation using a rat model of lumbar facet joint inflammation,” Spine, vol. 32, no. 4, pp. 406–412, 2007.

47. T. Taguchi, U. Hoheisel, and S. Mense, “Dorsal horn neurons having input from low back structures in rats,” Pain, vol. 138, no. 1, pp. 119–129, 2008.

48. T. Taguchi, V. John, U. Hoheisel, and S. Mense, “Neuroanatomical pathway of nociception originating in a low back muscle (multifidus) in the rat,” Neuroscience Letters, vol. 427, no. 1, pp. 22–27, 2007.

49. M. Miyagi, S. Ohtori, T. Ishikawa et al., “Up-regulation of TNFα in DRG satellite cells following lumbar facet joint injury in rats,” European Spine Journal, vol. 15, no. 6, pp. 953–958, 2006.

50. Y. Sakuma, S. Ohtori, M. Miyagi et al., “Up-regulation of p55 TNF alpha-receptor in dorsal root ganglia neurons following lumbar facet joint injury in rats,” European Spine Journal, vol. 16, no. 8, pp. 1273–1278, 2007.

51. J.-S. Kim, J. S. Kroin, A. Buvanendran et al., “Characterization of a new animal model for evaluation and treatment of back pain due to lumbar facet joint osteoarthritis,” Arthritis and Rheumatism, vol. 63, no. 10, pp. 2966–2973, 2011.

52. N. Attal, S. Perrot, J. Fermanian, and D. Bouhassira, “The neuropathic components of chronic low back pain: a prospective multicenter study using the DN4 questionnaire,” The Journal of Pain, vol. 12, no. 10, pp. 1080–1087, 2011.

53. H. Wang, M. Akbar, N. Weinsheimer, S. Gantz, D.-S. Wiss, and M. Schiltenworlf, “Longitudinal observation of changes in pain sensitivity during opioid tapering in patients with chronic low-back pain,” Pain Medicine, vol.

12, no. 12, pp. 1720–1726, 2011.

54. W.-R. Xie, H. Deng, H. Li, T. L. Bowen, J. A. Strong, and J.-M. Zhang, “Robust increase of cutaneous sensitivity, cytokine production and sympathetic sprouting in rats with localized inflammatory irritation of the spinal ganglia,” Neuroscience, vol. 142, no. 3, pp. 809–822, 2006.

55. G. M. Pitcher, J. Ritchie, and J. L. Henry, “Paw withdrawal threshold in the von Frey hair test is influenced by the surface on which the rat stands,” Journal of Neuroscience Methods, vol. 87, no. 2, pp. 185–193, 1999.

56. A. A. Fischer, “Pressure threshold meter: its use for quantification of tender spots,” Archives of Physical Medicine and Rehabilitation, vol. 67, no. 11, pp. 836–838, 1986.

Vernon H et al 57. T.-T. Yeh, Z.-H. Wen, H.-S. Lee et al., “Intra-articular injection of collagenase induced experimental osteoarthritis of the lumbar facet joint in rats,” European Spine Journal, vol. 17, no. 5, pp. 734–742, 2008.

58. K. E. Lee, M. B. Davis, R. M. Mejilla, and B. A. Winkelstein, “In vivo cervical facet capsule distraction: mechanical implications for whiplash and neck pain,” Stapp Car Crash Journal , vol. 48, pp.

373–395, 2004.

59. K. E. Lee, J. H. Thinnes, D. S. Gokhin, and B. A. Winkelstein, “A novel rodent neck pain model of facetmediated behavioral hypersensitivity: implications for persistent pain and whiplash injury,” Journal of Neuroscience Methods, vol. 137, no. 2, pp. 151–159, 2004.

60. K. E. Lee, A. N. Franklin, M. B. Davis, and B. A. Winkelstein, “Tensile cervical facet capsule ligament mechanics: failure and subfailure responses in the rat,” Journal of Biomechanics, vol. 39, no. 7, pp.

1256–1264, 2006.

61. K. P. Quinn, K. E. Lee, C. C. Ahaghotu, and B. A. Winkelstein, “Structural changes in the cervical facet capsular ligament: potential contributions to pain following subfailure loading,” Stapp Car Crash Journal, vol. 51, pp. 169–187, 2007.

62. H. S. Chen, J. Chen, and Y. Y. Sun, “Contralateral heat hyperalgesia induced by unilaterally intraplantar bee venom injection is produced by central changes: a behavioral study in the conscious rat,” Neuroscience Letters , vol. 284, no. 1-2, pp. 45–48, 2000.

63. N. G. Shenker, R. C. Haigh, P. I. Mapp, N. Harris, and D. R. Blake, “Contralateral hyperalgesia and allodynia following intradermal capsaicin injection in man,” Rheumatology, vol. 47, no. 9, pp. 1417–1421, 2008.

64. Y. Takahashi, S. Ohtori, and K. Takahashi, “Peripheral nerve pathways of afferent fibers innervating the lumbar spine in rats,” The Journal of Pain, vol. 10, no. 4, pp.

416–425, 2009.

65. K. E. Lee, M. B. Davis, and B. A. Winkelstein, “Capsular ligament involvement in the development of mechanical hyperalgesia after facet joint loading: behavioral and inflammatory outcomes in a rodent model of pain,” Journal of Neurotrauma, vol. 25, no. 11, pp. 1383–1393, 2008.

A selection of published research by CMCC faculty

66. K. E. Lee and B. A. Winkelstein, “Joint distraction magnitude is associated with different behavioral outcomes and substance P levels for cervical facet joint loading in the rat,” The Journal of Pain, vol. 10, no. 4, pp.

436–445, 2009.

67. H. J. Hu and R. W. Gereau, “ERK integrates PKA and PKC signaling in superficial dorsal horn neurons.

II. Modulation of neuronal excitability,” Journal of Neurophysiology, vol. 90, no. 3, pp. 1680–1688, 2003.

68. H. J. Hu, Y. Carrasquillo, F. Karim et al., “The Kv4.2 potassium channel subunit is required for pain plasticity,” Neuron, vol. 50, no. 1, pp. 89–100, 2006.

69. H. J. Hu, B. J. Alter, Y. Carrasquillo, C. S. Qiu, and R. W. Gereau, “Metabotropic glutamate receptor 5 modulates nociceptive plasticity via extracellular signal-regulated kinase-Kv4.2 signaling in spinal cord dorsal horn neurons,” Journal of Neuroscience, vol. 27, no. 48, pp.

13181–13191, 2007.

70. H. J. Im, X. Li, P. Muddasani et al., “Basic fibroblast growth factor accelerates matrix degradation via a neuro-endocrine pathway in human adult articular chondrocytes,” Journal of Cellular Physiology, vol. 215, no. 2, pp. 452–463, 2008.

71. H. J. Im, P. Muddasani, V. Natarajan et al., “Basic fibroblast growth factor stimulates matrix metalloproteinase-13 via the molecular cross-talk between the mitogen-activated protein kinases and protein kinase Cδ pathways in human adult articular chondrocytes,” The Journal of Biological Chemistry, vol.

282, no. 15, pp. 11110–11121, 2007.

72. X. Li, M. Ellman, P. Muddasani et al., “Prostaglandin E2 and its cognate EP receptors control human adult articular cartilage homeostasis and are linked to the pathophysiology of osteoarthritis,” Arthritis and Rheumatism, vol. 60, no. 2, pp. 513–523, 2009.

73. P. Muddasani, J. C. Norman, M. Ellman, A. J. vanWijnen, and H. J. Im, “Basic fibroblast growth factor activates the MAPK and NFκB pathways that converge on Elk-1 to control production of matrix metalloproteinase-13 by human adult articular chondrocytes,” The Journal of Biological Chemistry, vol. 282, no. 43, pp. 31409–31421, 2007.

Originally published in Pain Research and Treatment, Published online 2012, June 28. doi: 10.1155/2012/127636.

Open access article.

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CMCC Research Report 2012–2013

Mechanobiology, Injury and Health

Postural Influence on the Neutral Zone of the Porcine Cervical Spine Under Anterior–Posterior Shear Load Howarth SJ1, Gallagher KM2, Callaghan JP 2 1

Canadian Memorial Chiropractic College, 2 University of Waterloo

Abstract Segmental instability, characterized by excessive or aberrant movement of the vertebrae can be assessed quantitatively using mechanical characteristics within a region of minimal resistance called the neutral zone. The diagnosis of instability is often used to decide whether or not to surgically fuse the vertebrae. Alterations in flexion/ extension posture cause changes in both contact area and spacing between articulating facets that may lead to changes in the mechanical response of the functional spinal unit (FSU) within the neutral zone. This investigation quantified neutral zone (NZ) length under anterior and posterior shear loading and the influence of posture on the shear NZ characteristics of the vertebral joint. Thirty porcine cervical FSUs (15 C34 and 15 C56) were tested.

Endplate area was calculated from measurements of the exposed endplates while facet angles were measured from X-rays taken in the transverse plane. Specimens were exposed to a 300 N compressive preload followed by a test to determine flexion/extension NZ limits. These limits were used as target angles during shear passive tests performed in extended and flexed postures.

Displacement rate during shear passive tests was 0.2

mm/s and five cycles of anterior–posterior shear were performed to a target of ±400 N in a randomized order of extended, neutral and flexed postures. Shear NZ length and average stiffness were quantified. Stiffness within the shear NZ was 67 N/mm in the neutral posture.

Extended postures produced a 37% (P < 0.0001) increase in shear stiffness within the NZ compared to both flexed and neutral postures. Posture did not influence shear NZ length. Therefore, a true region of zero stiffness does not exist during shear loading with a baseline compressive load. Neutral zone length for the porcine FSU exposed to shear load was not influenced, despite known changes in facet articulation, by changing posture. Average stiffness increased likely as a result of increased contact area and force in extension. The results from this investigation demonstrate that postural deviation of the vertebral joint is not likely a significant confounding factor when assessing segmental stability.

Originally published in Medical Engineering and Physics.

Jul;35(7):910-8. doi: 10.1016/j.medengphy.2012.08.019.

Epub 2012 Sep 16. Reprinted with permission from Elsevier.

Interprofessional and Educational

Manikin-Based Clinical Simulation in Chiropractic Education McGregor M, Giuliano D Canadian Memorial Chiropractic College

Abstract Objective The purpose of this pilot investigation was to describe the development and implementation of simulation exercises and investigate the feasibility, satisfaction, and relative effectiveness of a manikin-based simulation program in chiropractic undergraduate education.

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Methods This investigation consisted of (1) a qualitative review of other simulation environments and evaluation of related simulation literature to develop the educational processes to be used, (2) implementation of simulation scenarios for 95 student interns and their 11 supervising clinicians, and (3) implementation

A selection of published research by CMCC faculty

of simulation scenarios in a random sample of 35 1st-year and 24 2nd-year chiropractic students. Assessment of success was based on results from satisfaction and usability questionnaires and perceived achievement of learning outcomes. Anxiety scores were measured for all participants via a visual analog scale. The level of successful integration of 2nd-year basic science material was assessed using a t test comparing test results between students who participated in the pilot and those who did not.

Results Implementation methods were developed on the basis of qualitative investigation. Simulation program feedback from all participants indicated high levels of satisfaction, usability, and perceived achievement of learning outcomes.

Anxiety levels among interns differed according to role chosen (F = 8.07, p =.00). Mean difference in course examination scores of students who participated in simulations versus those who did not was 3.25% favoring students who participated (t = 1.28, p =.10).

Conclusions High levels of student satisfaction and perceived achievement of learning outcomes were consistently achieved. A trend to successful integration of basic science knowledge provides reason for cautious optimism. More research is recommended.

Originally published in the Journal of Chiropractic Education, 2012 Spring:26(1):14-23. Reprinted with permission.

â&#x20AC;&#x201A; Mechanobiology, Injury and Health

The Association Between Self-Reported Cardiovascular Disorders and Troublesome Neck Pain: A PopulationBased Cohort Study Nolet PS1, CĂ´tĂŠ P1, 2, 3, Cassidy JD2, 3, 4 , Carroll LJ5 1

Canadian Memorial Chiropractic College, 2 University of Toronto, 3 Toronto Western Hospital, 4 University of Southern Denmark, 5 University of Alberta

Abstract Objective The purpose of this population-based cohort study was to investigate the association between self-reported cardiovascular disorders and troublesome neck pain.

Methods Using data from the Saskatchewan Health and Back Pain Survey (1995), we formed a cohort of 922 randomly sampled Saskatchewan adults with no or mild neck pain. We used the Comorbidity Questionnaire to measure the point prevalence of self-reported cardiovascular disorders and classified them into 3 levels of severity: (1) absent, (2) present but does not or mildly impacts on my health, and (3) present and moderately or severely impacts on my health. Six and 12 months later, we measured the presence of troublesome neck pain (grades II-IV) using the Chronic Pain Questionnaire. Multivariable Cox regression was used to estimate the association between cardiovascular disorders and the troublesome neck pain while controlling for confounders.

Results The follow-up rate was 73.8% (680/922) at 6 months and 62.7% (578/922) at 1 year. No association was found between selfreported cardiovascular disorders that had no or mild impact on health and the onset of troublesome neck pain. We found a crude association between self-reported cardiovascular disorders that moderately or severely impacted health and the onset of troublesome neck pain (crude hazard rate ratio, 4.3; 95% confidence interval, 1.8-10.0). The association was positively confounded by age, sex, and education (adjusted hazard rate ratio, 5.9; 95% confidence interval, 2.3-14.9).

Conclusions Our analysis suggests that self-reported cardiovascular disorders that moderately or severely impact one's health are a risk factor for developing troublesome neck pain.

Originally published in the Journal of Manipulative and Physiological Therapeutics, 2012 Mar-Apr;35(3):176-83. doi: 10.1016/j.jmpt.2012.01.006. Epub 2012 Feb 24. Reprinted with permission from Elsevier.

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CMCC Research Report 2012–2013

Basic Sciences

Short-Term Effects of Manipulation to the Upper Thoracic Spine of Asymptomatic Subjects on Plasma Concentrations of Epinephrine and Norepinephrine — A Randomized and Controlled Observational Study Puhl A, Injeyan HS Canadian Memorial Chiropractic College

Abstract Objective The purpose of this study was to investigate the short-term effects of spinal manipulation applied to a hypomobile segment of the upper thoracic spine (T1-T6), on plasma concentrations of norepinephrine (NE) and epinephrine (E) in asymptomatic subjects, under strictly controlled conditions.

Methods Fifty-six asymptomatic subjects were randomly assigned to receive either a chiropractic manipulative intervention or a sham intervention in the upper thoracic spine. A 20-gauge catheter fitted with a saline lock was used to sample blood before, immediately after, and 15 minutes after intervention. Plasma NE and E concentrations were determined using an enzyme-linked immunosorbent assay.

Changes in plasma catecholamine concentrations were analyzed within and between groups using 1- and 2-sample t tests, respectively.

Results The plasma samples of 36 subjects (18 treatment, 18 control) were used in the analysis. Mean plasma concentrations of NE and E did not significantly differ between the 2 groups at any time point and did not change significantly after either the manipulative or sham intervention.

Conclusions The results of this study indicate that a manipulative thrust directed to a hypomobile segment in the upper thoracic spine of asymptomatic subjects does not have a measurable effect on the plasma concentrations of NE or E. These results provide a baseline measure of the sympathetic response to spinal manipulation.

Originally published in the Journal of Manipulative and Physiological Therapeutics, 2012 Mar-Apr;35(3):209-15. doi: 10.1016/j.jmpt.2012.01.012. Epub 2012 Feb 17. Reprinted with permission from Elsevier.

Basic Sciences

Connective Tissue Infiltration and Subcutaneous Fat in Fascioscapulohumeral Muscular Dystrophy-Affected Biceps Brachii Muscle Sovak G, Triano JJ, Soave D, Tran S, Johnston L, Edwards M Canadian Memorial Chiropractic College

Background Facioscapulohumeral muscular dystrophy (FSHD) is the third most common of the inherited muscular dystrophies.

28

Quantitative ultrasound has been used to evaluate the severity of pathology and the relationship of pathology with strength

A selection of published research by CMCC faculty

and function. This feasibility study examined quantitatively the content of epimuscular fat and intramuscular connective tissue vs clinical severity scale (CSS) as a baseline for elastographic estimates of tissue strata strain, in progress.

Quantifying the differences between distributions of epimuscular fat and intramuscular connective tissue in FSHD and healthy controls may allow for a better understanding of how muscle distributes load during motion.

when compared to the healthy controls. There were no significant correlations found between CSS measurements and the amount of subcutaneous fat. A significant positive correlation was found between clinical severity and connective tissue/fat muscle infiltration (r=0.82) while a significant negative (r=−0.76) correlation was found between biceps muscle circumference and connective tissue/fat infiltration, and between muscle strength and connective tissue/fat infiltration (r=−0.91).

Methods A total of 17 subjects, including FSHD (n=8) and controls (n=9), were analyzed. The biceps brachii muscles of all subjects were evaluated using ultrasound technology (Ultrasonix, Burnaby, BC). Clinical severity was estimated by CCS. Echogenicity of connective tissue/fat and subcutaneous fat were calculated using MATLAB software specifically programmed to quantify the muscle content of connective tissue and fat.

Conclusion Patients with FSHD have an increased amount of connective tissue/fat infiltration in their biceps brachii and an increase in overlying subcutaneous fat compared to controls. The more severe the FSHD is the greater amount of connective tissue/fat infiltration. Subcutaneous fat was not related to clinical severity.

Results Patients with FSHD consistently demonstrated an increase in connective tissue/fat infiltration and subcutaneous fat

Originally published in the Journal of Bodywork and Movement Therapies, 2012 April;16(2):154-155. doi: 10.1016/ j.jbmt.2012.01.068. Reprinted with permission from Elsevier.

Interprofessional and Educational

Biomechanics – Review of Approaches for Performance Training in Spinal Manipulation Triano JJ1, Descarreaux M2, Dugas C2 1

Canadian Memorial Chiropractic College, 2 Université du Québec à Trois-Rivières

Abstract Motor skills development is an inherent part of clinical training in health disciplines. The conscious use of educational theory to ground learning is receiving increasing attention across health care education. There are three distinct, yet overlapping, stages of motor skill learning; the cognitive, the integrative or associative, and the autonomous; in which a contextual framework for learning content may be structured. The learning is associated with a mapping of changes within the central nervous system by the interactive mechanisms of adaptation, use-dependent plasticity and operant reinforcement.

Successful skill learning requires a sufficient amount of practice and the implementation of relevant feedback strategies in the form of knowledge of performance (KP) or

knowledge of results (KR). There is a natural maturation of skills that may be accelerated by feedback. Several factors contribute to stronger skills development. “Mixtureof-experts” models systematically sequence tasks into logical blocks of theory, practice and student reflection on performance. Feedback should involve both KP and KR that compares performance to a tangible standard. Rehearsals should balance use of simulators and volunteer simulated patients to provide the full range of safe and effective learning opportunities prior to students accepting a role as care givers to the public in any clinical setting.

Originally published in the Journal of Electromyography and Kinesiology, 2012 Oct;22(5):732-9. doi: 10.1016/ j.jelekin.2012.03.011. Epub 2012 Apr 28. Reprinted with permission from Elsevier.

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CMCC Research Report 2012–2013

Clinical Sciences

Validation of a Novel Sham Cervical Manipulation Procedure Vernon HT, Triano JJ, Ross JK, Tran SK, Soave DM, Dinulos MD Canadian Memorial Chiropractic College

Abstract Background context No clinical trial of spinal manipulation for chronic neck pain (NP), for either single or multiple intervention session(s), has used an effective manual sham-manipulation control group.

Purpose Validate a practical sham cervical high-velocity low-amplitude spinal manipulation.

Study design/setting Randomized experimental validation study in an institutional clinical research laboratory.

Patient sample Eligible subjects were males and females, 18 to 60 years of age with mechanical NP (as defined by the International Association for the Study of Pain Classification) of at least 3 months' duration. Subjects with arm pain, any pathologic cause of NP, or any contraindication to spinal manipulation were excluded.

Outcome measures The primary outcome was the patient's self-report or registration of group allocation after treatment. Secondary outcomes were numerical rating scale-101 for NP, range of motion (ROM; by goniometer), and tenderness (by pressure algometry).

Methods Eligible subjects were randomly allocated to one of two groups: real cervical manipulation (RM) or sham cervical manipulation (SM). All subjects were given two procedures in sequence, either RM+SM or SM+SM. Immediately after the two procedures, subjects were asked to register any pain experienced during the procedures and to identify

30

their treatment group allocation. Force-time profiles were recorded during all procedures. Secondary clinical outcome measures were obtained at baseline, 5 and 15 minutes after the intervention, including ROM, self-report of pain, and local spinous process tenderness. Data for each variable were summarized and tested for normality in distribution.

Summary statistics were obtained for each variable and statistically tested.

Results Sixty-seven subjects were randomized. Data from 64 subjects (32 per group) were available for analysis. There were no significant differences between the groups at baseline. One adverse event occurred in the “real” group, which was a mild posttreatment pain reaction lasting less than 24 hours. In the RM group, 50% of subjects incorrectly registered their treatment allocation; in the sham group, 53% did so. For the SM group, none of the procedures resulted in cavitation, whereas in the RM group, 87% of procedures resulted in cavitation. There were no significant changes between groups on pain, tenderness, or ROM. Force-time profiles of the RM and SM procedures demonstrated fidelity with significant differences between components as intended.

Conclusions The novel sham procedure has been shown to be effective in masking subjects to group allocation and to be clinically inert with respect to common outcomes in the immediate posttreatment stage. Further research on serial applications and for multiple operators is warranted.

Originally published in Spine Journal 2012 Nov;12(11):10218. doi: 10.1016/j.spinee.2012.10.009. Epub 2012 Nov 15.

Reprinted with permission from Elsevier.

A selection of published research by CMCC faculty

â&#x20AC;&#x201A; Interprofessional and Educational

A Diachronic Study of the Language of Chiropractic Budgell BS1, Kwong A1, Millar N2 Canadian Memorial Chiropractic College, 2University of Birmingham

1

Abstract This study investigates how the language of chiropractic has changed over time. A collection of material, published up until approximately 1950 and consisting of textbooks, monographs and lecture notes from Canadian Memorial Chiropractic College, was analyzed to identify commonly occurring words and phrases. The results were compared to a corpus of recent articles from the Journal of the Canadian Chiropractic Association. This permitted the identification of words which were over-represented in the historical literature and therefore likely have become somewhat archaic or represent themes which are of less import in the modern chiropractic literature. Words which

were over-represented in the historical literature often referred to anatomical, pathological and biomechanical concepts. Conversely, words which were comparatively over-represented in the modern chiropractic literature often referred to concepts of professionalism, the clinical interaction and evidence-based care. A detailed analysis is presented of trends in the use of the conceptually important terms subluxation and adjustment.

Originally published in the Journal of the Canadian Chiropractic Association, 2013 Mar;57(1):49-55. Reprinted with permission.

â&#x20AC;&#x201A; Interprofessional and Educational

The Language of Integrative Medicine Budgell BS Canadian Memorial Chiropractic College

Abstract Biomedical language, also known as biomedical English, is sufficiently different from general English to warrant treatment as a distinct language. Biomedical language has its own conventions of grammar, phraseology and discourse, as well as a lexicon which is complex and esoteric. Furthermore, each subdiscipline, such as integrative medicine, has a unique vocabulary which must be mastered in order to achieve fluency. In this

article, the vocabulary specific to acupuncture is identified, and strategies are introduced to master the use of that vocabulary.

Originally published in the Journal of Chinese Integrative Medicine: 2013 May;11(3):229-32. doi: 10.3736/ jintegrmed2013026. Open access article. Reprinted with permission from Dr. B.S. Budgell.

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CMCC Research Report 2012–2013

Mechanobiology, Injury and Health

Coping and Recovery in Whiplash-Associated Disorders: Early use of Passive Coping Strategies is Associated With Slower Recovery of Neck Pain and Pain-Related Disability Carroll LJ1, Ferrari R2, Cassidy JD2,5, Côté P3, 4 University of Alberta, 2University of Toronto, 3University of Ontario Institute of Technology (UOIT), 4 Canadian Memorial Chiropractic College, University of Southern Denmark

1 5

Abstract Objective Coping is shown to affect outcomes in chronic pain patients; however, few studies have examined the role of coping in the course of recovery in whiplash-associated disorders (WAD).

The purpose of this study was to determine the predictive value of coping style for 2 key aspects of WAD recovery, reductions in neck pain, and in disability.

Methods A population-based prospective cohort study design was used to study 2986 adults with traffic-related WAD. Participants were assessed at baseline, 6 weeks, and 4, 8, and 12 months post injury. Coping was measured at 6 weeks using the Pain Management Inventory, and neck pain recovery was assessed at each subsequent followup, using a 100 mm visual analogue scale (VAS). Disability was assessed at each follow-up using the Pain Disability Index (PDI). Pain recovery was defined as a VAS score of 0 to 10; disability recovery was defined as a PDI score of

32

0 to 4. Data analysis used multivariable Cox proportional hazards models.

Results Those using high versus low levels of passive coping at 6 weeks post injury experienced 28% slower pain recovery and 43% slower disability recovery. Adjusted hazard rate ratios for pain recovery and disability recovery were 0.72 (95% CI, 0.59-0.88) and 0.57 (95% CI, 0.41-0.78), respectively. Active coping was not associated with recovery of neck pain or disability.

Conclusions Passive coping style predicts neck pain and self-assessed disability recovery. It may be beneficial to assess and improve coping style early in WAD.

Originally published in the Clinical Journal of Pain, 2013 Feb 26. [Epub ahead of print]. Reprinted with permission from Wolters Kluwer Health.

A selection of published research by CMCC faculty

Mechanobiology, Injury and Health

The Association Between Workers’ Compensation Claims Involving Neck Pain and Future Health Care Utilization: A Population-Based Cohort Study Côté P1,2 , Yang X 3, Kristman V4,5, Hogg-Johnson S5, Van Eerd D6, Rezai M7, Vidmar M8 University of Ontario Institute of Technology, 2 Canadian Memorial Chiropractic College, 3Abbott Laboratories, 4Lakehead University, 5University of Toronto, 6University of Waterloo, 7University Health Network, 8Toronto Health Economics and Technology Assessment (THETA) Collaborative 1

Abstract Purpose To describe the health care utilization of injured workers who made a workers’ compensation claim for neck pain.

Methods We conducted a cohort study of injured workers who made an incident claim involving neck pain to the Ontario Workplace Safety and Insurance Board between 1997 and 1998. We linked their workers’ compensation and Ontario Health Insurance Plan files to collect all health care services accrued during the year prior to and 2 years after the claim was initiated. We report the 7 day simple moving average of health care services per 1,000 claimants per day. We stratified our analysis by age, sex, the pre-claim level of health care utilization, diagnostic category and health care specialty.

Results 58.1 % of claimants were males and 35.1 % were between

the ages of 35 and 44 years. The cumulative rate of health care utilization was stable (mean = 60.80 services/1,000 claimants/day; 95 % CI: 59.7–62.0) throughout the year prior to the claim. However, it peaked during the first 4 days following the onset of the claim (mean = 473.3 services/1,000 claimants/ day) and remained on average 311 % higher than baseline during the first month postclaim. On average in our sample, the health care utilization remained 11 % higher in the second year after the claim compared to the pre-claim level. This sustained increase was attributable to 6 % of claimants.

Conclusions We report a long-term increase in the average number of health care services utilized by injured workers who make a workers’ compensation claim involving neck pain. This increase was attributable to a minority of claimants. The health reasons for this increase deserve further investigation.

Introduction Neck pain is endemic in workers. International statistics suggest that the annual prevalence of neck pain ranges from 27.1 % in Norway to 47.8 % in Canada [1]. Each year, 11 to 14.1 % of workers experience neck pain that interferes with their daily activities [2, 3]. In Ontario, neck pain is involved in more than 10 % of all workers’ compensation claims [4]. While neck pain is a common cause of work absenteeism, it also impacts on work productivity. In Sweden, 49 % of workers with neck/upper back pain report that they went to work despite feeling that they should have taken time off work because of their pain [5].

Although neck pain is a benign and self-limiting condition, the current evidence suggests that it runs a persistent and episodic course. It is estimated that between 60 and 80 %

of workers with prevalent neck pain will report neck pain 1 year later [6]. Moreover, 14.2 % of injured workers who make a workers’ compensation claim involving neck pain will experience recurrences of work absenteeism during the 2 years following their initial claim [7]. Little is known about the impact of work-related neck pain on the health of workers, on their utilization of health care services and on the health care system. Gaining knowledge in this area is necessary to understand, from a public health perspective, the long-term impact of musculoskeletal disability claims on workers and on our health care system.

Reporting a sickness absence usually triggers interactions with the health care system. During these interactions, the

33

CMCC Research Report 2012–2013

clinician treats the injured worker with the goal of safely returning the worker to work. Therefore, it is assumed a worker’s health and utilization of health care services should return to its pre-claim levels after successful returnto-work. However, a study of health care workers who made a workers’ compensation claim for musculoskeletal disorders suggests that the rate of consultation with general practitioners remains elevated for more than 5 years after the claim [8]. Possible reasons for the sustained elevation in health care utilization include the need to seek care for persistent or recurrent musculoskeletal pain or for the care of other health conditions. Our primary objective was to determine whether the post-claim rate of health care utilization returns to its preclaim level in a cohort of Ontario injured workers who made a disability claim for neck pain to the Ontario Workplace Safety and Insurance Board. Given the nonpathological nature of most work-related neck pain and its favorable prognosis, we hypothesized that health care utilization would return to its pre-claim level. Our secondary objectives were to determine whether the pre and post health care utilization varied according to age, sex, preclaim levels of health care utilization, health care specialty and diagnostic categories. Finally, we compared health care utilization before and after the introduction of the new workers’ compensation law in Ontario.

Methods The Context In 2001, Ontario was a Canadian province of 11.4 million inhabitants with a universal health care system [9]. Work related injuries and diseases are compensable by the Workplace Safety and Insurance Board, a public no-fault insurer legislated by the Workplace Safety & Insurance Act [10]. Approximately 65 % of Ontario workers are covered by the Workplace Safety and Insurance Board. The health care costs incurred by injured workers are reimbursed by the workers’ compensation board. Workers who are self employed or employed by self-insured companies are not covered by the Workplace Safety and Insurance Board.

On January 1, 1998, the Ontario government introduced a new workers’ compensation law (Bill 99) which modified the management of return-to-work [10]. According to Bill 99, employers and workers are required to communicate with each other, identify early appropriate employment and provide the Workplace Safety and Insurance Board with information concerning the return-to-work process [10, 11]. The role of the Workplace Safety and Insurance Board is to assist employers and workers to achieve safe and early return-to-work. These measures were put in place to accelerate early and safe return-to-work. The Workplace

34

Safety and Insurance Act remains (in 2012) the law used to regulate workers’ compensation in Ontario.

Study Design We conducted a population-based cohort study of Ontario workers aged 18 years or older who made a lost-time claim to the Workplace Safety and Insurance Board between January 1, 1997 and December 31, 1998. This study period was selected because it corresponds to the introduction of a new workers’ compensation law in Ontario.

Study Population We included workers who filed an incident lost-time claim for a soft tissue injury to the neck. We defined incident neck pain claims as a workers compensation claim for a neck injury in 1997 and 1998 with no claims for neck injuries in the year prior to the index claim. We created the cohort using administrative data from the Workplace Safety and Insurance Board and identified cases by combining part of body and nature of injury codes. The part of body codes were used to determine the location of the injury.

The nature of the injury code was used to identify acute or repetitive injuries. The methodology used to identify losttime claimants is described in detail elsewhere [12]. We have reported that the positive predictive value for this method is 88.2 % in identifying soft tissue injuries to the neck [12].

We excluded workers with fractures or dislocations of the cervical spine or shoulder and those with burns, lacerations, or infections to the head, neck or shoulder area.

Data Sources We used two independent and complimentary sources of administrative data. First, data from the Workplace Safety and Insurance Board was used to collect the claimant’s age, sex, date of accident, part of body, nature of injury, dates of health care services and the health care specialty (medical doctors, chiropractors, physiotherapists and massage therapists).

Second, we used data from the Ontario Health Insurance Plan to collect the claimant’s age, sex, diagnostic information (ICD-9 codes), service dates and health care provider specialty (physicians, physiotherapists or chiropractors) for all services that were submitted to Ontario Health Insurance Plan for reimbursement [13]. All health care services accrued during the year prior to the injury date and during the 2 years following the claim were used in the analysis.

Data Linkage We used record linkage to link Workplace Safety and Insurance Board claim numbers to Ontario Health Insurance Plan health card numbers. We used two files maintained at the Workplace Safety and Insurance Board. The first one

Côté P et al

was derived from Workplace Safety and Insurance Board administrative records and included the claim number.

The second file included the health card number and was provided to the Workplace Safety and Insurance Board by the Ontario Ministry of Health and Long-Term Care. The files had four fields in common: first name, last name, date of birth and gender. We first linked the files deterministically by identifying exact matches on all four fields. Second, we considered various partial matches based on two or three fields. Two reviewers independently reviewed and agreed that all partial matches for mismatches were due to alterations in the spelling of names, the use of nick names or switches between the day and month of birth.

The Workplace Safety and Insurance Board and Ontario Health Insurance Plan data were linked by the Ontario Ministry of Health and Long-Term Care using the health card number, a unique identifier assigned to each registered beneficiary. To protect confidentiality, the Ontario Ministry of Health and Long-Term Care removed all identifiers from the study files. The University of Toronto Research Ethics Board approved the study (Protocol Reference: #00011747).

Health Care Utilization We measured the daily number of health care services made to the most frequently used providers (general practitioners, medical specialists, chiropractors, physiotherapists and massage therapists) during the year before and 2 years after the claim. A service is defined as a consultation with a specific type of health-care provider that is reimbursed by the Ontario Health Insurance Plan or the Workplace Safety and Insurance Board. For example, an injured worker who consults a general practitioner and a rheumatologist on the same day would contribute two services for that day.

Individuals with multiple reimbursements to the same health car provider on a single day were allocated one service to that specific provider for that day.

Analysis We first determined whether our sample was representative of all Workplace Safety and Insurance Board claimants with neck pain by comparing the age, sex and claim duration (cumulative number of days receiving disability benefits) of claimants whose data were linked to the characteristics of those whose data were unable to be linked. We computed the rates of health care utilization and 95 % confidence intervals (CI) as a 7 day simple moving average of health care services per 1,000 claimants per day. We did not restrict our analysis to services provided for neck pain; rather we used all health care services accrued during the study period. We describe the health care utilization for six consecutive periods: (1)

A selection of published research by CMCC faculty

the pre-claim period (the year prior to the claim) and five post-claim periods: (2) 0–4 weeks; (3) 5–12 weeks; (4) 13-24 weeks; (5) 25–52 weeks; and( 6) 53–104 weeks post-claim.

We computed the proportion of claimants that contributed to the variation in health care utilization at follow-up. This was achieved in three steps. First, we calculated the monthly pre-claim proportion of claimants with higher utilization than in the twelfth month prior to the claim. Similarly, we computed the monthly proportion of claimants with higher utilization at follow-up than in the twelfth month prior to the claim. Finally, the proportion of claimants that contributed to the change in the rate of utilization above and beyond expected fluctuations was computed by subtracting the preclaim from the follow-up proportions.

We report the rates stratified by age group, sex, preclaim level of health care utilization (low users:<median vs. high users: ≤median), claim duration (≤90 days vs. <90 days), health care specialty, broad diagnostic categories and by year (1997 and 1998). All analyses were conducted using SAS, version 9.1, statistical software (SAS Institute, Inc., Cary, North Carolina).

Results Study Sample A total of 6,434 claimants made an incident lost-time claim involving neck pain between January 1, 1997 and December 31, 1998. Of those, 29 were excluded because they were younger than 18 years of age. Of the remaining 6,405 claimants, data linkage was not possible for 1,601 claimants because their Ontario Health Insurance Plan card numbers could not be retrieved. Finally, data linkage was not possible for 128 claimants whose Workplace Safety and Insurance Board health care services could not be found. Therefore, we were able to link the data for 74.7 % of the eligible population (n = 4,804). The health card numbers could not be retrieved because they were missing from the Workplace Safety and Insurance Board data file or because we could not identify a match in the record linkage process. Duringthe study period, these claimants accrued 393,318 billing records from the Ontario Health Insurance Plan and 14,055 billing records from the Workplace Safety and Insurance Board.

We found differences between the claimants whose data were linked versus those whose data were not linked.

Specifically, the proportion of females was higher in claimants whose data were not linked (47.9 %) compared to those whose data were linked (41.9 %) (Table 1). Similarly, the proportion of claimants with claim duration B90 days was higher in claimants whose data were not linked (79.8 %) compared to those whose data were linked (74.1 %) (Table 1).

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CMCC Research Report 2012–2013

The cohort of claimants included in our analysis included mainly males (58.1 %) and 35.1 % were between the ages of 35 and 44 years (Table 1). Most injured workers included in the analysis (54.7 %) filed their claim in 1997 and 45.3 % in 1998 (Table 1). There were no important differences between the characteristics of the 1997 and 1998 claimants (data not shown).

Cumulative Health Care Utilization The cumulative rate of health care utilization was stable (mean = 60.80 services/1,000 claimants/day; 95 % CI: 59.7–62.0) throughout the year prior to the claim (Table 2).

The rate peaked during the first 4 days following the claim (mean = 473.3 services/1,000 claimants/day) and remained on average 311 % higher than baseline during the first month post-injury (mean = 250.0 services/1,000 claimants/day; 95 % CI: 192.6–307.4). The rate of utilization declined rapidly but did not return to its pre-claim level. From the sixth to twelfth month post-claim, an average of 82.6 services/1,000 claimants/day (95 % CI: 80.7–84.5) were made by our cohort.

The rate of health care utilization was stable during the second year of follow-up but remained 11 % higher (67.7 services/1,000 claimants/day; 95 % CI: 66.7–68.7) than the pre-claim level (Table 2).

Table 1 Baseline characteristics for claimants with linked data versus claimants without linked data Characteristic

Claimants with linked data (n = 4,804)

Claimants without linked data (n = 1,601)

No.

%

No.

%

Male

2,793

58.1

834

52.1

Female

2,011

41.9

766

47.9

Sex

Age 18 ≤ Age <25

401

8.4

143

8.9

25 ≤ Age < 35

1,495

31.1

513

32.0

35 ≤ Age < 45

1,684

35.1

563

35.2

45 ≤ Age < 55

941

19.6

305

19.1

Claim duration Duration ≤ 90 days

3,559

74.1

1277

79.8

Duration > 90 days

803

16.7

122

7.6

No information

442

9.2

202

12.6

Claim year

36

1997

2,629

54.7

837

52.3

1998

2,175

45.3

764

47.7

Côté P et al

A selection of published research by CMCC faculty

Table 2 Cumulative rate of health care utilization (HCU) per 1,000 workers per day (95 % CI) among injured workers who made a workers’ compensation claim for neck pain to the Ontario Workplace Safety and Insurance Board in 1997–1998 Characteristic Overall

Baseline

0–4 week

5–12 week

13–24 week

25–52 week

53–104 week

60.8 (59.7, 62.0)

250.0 (192.6, 307.4)

123.4 (116.6, 130.2)

96.1 (92.9, 99.4)

82.6 (80.7, 84.5)

67.7 (66.7, 68.7)

Sex Male

47.3 (46.1, 48.4)

242.7 (178.2, 307.2)

105.4 (98.6, 112.2)

78.2 (75.0, 81.4)

66.6 (64.7, 68.5)

53.3 (52.3, 54.3)

Female

79.6 (77.7, 81.5)

260.1 (212.3, 307.9)

148.5 (140.3, 156.6)

121.0 (116.5, 125.5)

104.8 (102.1, 107.5)

87.6 (86.1, 89.1)

18 ≤ Age < 25

43.0 (40.3, 45.8)

204.2 (134.8, 273.6)

83.9 (74.5, 93.4)

67.6 (60.6, 74.6)

54.7 (50.8, 58.6)

46.6 (44.9, 48.6)

25 ≤ Age < 35

54.0 (52.4, 55.6)

223.8 (164.9, 282.7)

104.9 (98.5, 111.2)

83.3 (79.7, 86.9)

73.4 (71.0, 75.8)

59.0 (57.8, 60.2)

35 ≤ Age < 45

60.0 (58.4, 61.7)

266.3 (208.8, 323.9)

129.3 (121.4, 137.3)

94.6 (89.7, 99.4)

80.1 (77.7, 82.5)

66.7 (65.4, 68.0)

45 ≤ Age < 55

71.5 (69.2, 73.9)

257.9 (204.3, 311.5)

136.3 (127.2, 145.5)

114.6 (108.7, 120.5)

98.5 (94.8, 102.3)

82.1 (80.2, 84.1)

Age C 55

90.9 (86.0, 95.7)

329.8 (274.9, 384.6)

199.0 (180.3, 217.7)

151.8 (142.9, 160.7)

132.7 (125.8, 139.7)

101.0 (97.4, 104.7)

Age

Baseline HCU < Median

15.5 (15.1, 15.9)

214.3 (153.5, 275.2)

87.6 (81.6, 93.7)

60.3 (57.6, 63.0)

53.7 (52.1, 55.3)

32.2 (30.8, 33.6)

≤ Median

105.3 (103.2, 107.5)

285.0 (230.7, 339.4)

158.6 (150.3, 166.8)

131.3 (126.6, 136.1)

111.0 (108.2, 113.8)

102.5 (101.1, 104.0)

Claim duration ≤ 90

58.9 (57.7, 60.2)

242.0 (184.7, 299.4)

106.3 (99.6, 112.9)

79.0 (76.2, 81.8)

71.8 (70.1, 73.6)

63.4 (62.4, 64.4)

> 90

71.0 (68.3, 73.6)

335.4 (277.5, 393.4)

224.7 (211.9, 237.5)

181.7 (173.3, 190.1)

138.9 (134.3, 143.5)

90.1 (87.7, 92.6)

1997

61.0 (59.6, 62.4)

248.6 (194.6, 302.6)

124.3 (116.5, 132.1)

97.7 (93.8, 101.6)

85.2 (82.9, 87.5)

69.2 (67.9, 70.4)

1998

60.6 (59.0, 62.1)

251.7 (189.9, 313.5)

122.3 (115.9, 128.8)

94.2 (90.5, 97.9)

79.5 (77.2, 81.8)

65.9 (64.7, 67.0)

Claim year

37

% of injured workers

CMCC Research Report 2012–2013

Health Care Utilization by Pre-Claim Utilization and Claim Duration Workers classified as low pre-claim utilization users (<median) continued to use fewer services than the high users (≤ median) (Table 2). The rate of utilization grew by 13.8 times among low users after the onset of the claim; while it only grew by 2.7 times for the high users. During the second year of follow-up, the average number of health services accrued by high users was slightly below the preclaim period while it was twice as high for low users (Table 2). Despite this difference in post-claim utilization the low users were still substantially lower than the high users in the second year.

100 90 80 70 60 50 40 30 20 10 0 -12 -1 0 - 8 - 6 - 4 - 2 1 3 5 7 9 11 1 3 15 17 19 2 1 2 3

30-day time period relative to date of injury Fig. 1 Monthly-specific percentage of injured workers with higher health care utilization compared to baseline (–12 months) covering a period of one year prior to 2 years after the claim

On average during the eleven months prior to the claim, 28 % (range 26 % to 29 %) of claimants used more health care services than in the twelfth month prior to the claim (Fig. 1). This proportion increased to 90 % in the month following the claim but was down to 40 %, 36 % and 34 % respectively 6, 12 and 24 months after the claim.

Therefore, the sustained increase in health care utilization was attributable to 62 %, 12 %, 8 % and 6 % of claimants respectively at 1, 6, 12 and 24 months post claim.

Age- and Sex-Specific Health Care Utilization Women and older claimants had higher rates of health care utilization throughout the study (Table 2). However, men and those younger than 45 years experienced a more rapid growth in their utilization than women and older workers.

For example, men used 5.1 times more services during the first 4 weeks following the onset of the claim than during the pre-injury period. During the same period, the utilization for women grew by a factor of 3.2.

Claimants who were on benefits for more than 90 days had a utilization rate that was 1.95 times higher at 25 to 52 weeks compared to before the claim (Table 2). While the increase was smaller for workers who received lost time benefits for ≤90 days it was nevertheless higher (1.22 times) than the pre-claim level.

1997 Versus 1998 Cohorts We found no difference in the pre-claim cumulative rate of utilization for workers who initiated their claims in 1997 and those who did in 1998. Similarly, the rates were similar between the 1997 and 1998 cohorts for the first 6 months after the onset of the claim. However, 6 to 12 months following the claim, workers in the 1997 cohort used an average of 5.7 more health care services per day per 1,000 claimants than those in the 1998 cohort (Table 2).

This difference decreased to 3.3 services per day per 1000 claimants during the second year of follow-up.

Health Care Utilization by Health Care Specialty Most health care services reimbursed by the Ontario Health Insurance Plan were provided by general practitioners and family physicians (Table 3).

Table 3 Cumulative rate of health care utilization per 1,000 workers per day (95 % CI) stratified by health care specialty Health Care Specialty

Baseline

0–4 week

5–12 week

13–26 week

27–52 week

53–104 week

General and family practice

23.9 (23.5, 24.4)

127.7(96.9, 158.4)

53.9 (50.7, 57.2)

39.3 (37.8, 40.8)

33.1 (32.3, 33.9)

26.2 (25.9, 26.6)

Pathology

11.2 (10.7, 11.7)

16.0 (14.5, 17.5)

13.3 (11.8, 14.9)

13.0 (12.0, 14.1)

13.2 (12.4, 14.0)

12.2 (11.8, 12.6)

Chiropractic

4.3 (4.2, 4.4)

13.7 (12.6, 14.8)

6.6 (6.2, 7.0)

7.2 (6.9, 7.5)

6.3 (6.1, 6.5)

4.6 (4.5, 4.7)

Diagnostic radiology

2.7 (2.6, 2.8)

18.2 (10.7, 25.8)

5.2 (4.8, 5.5)

4.5 (4.2, 4.8)

3.9 (3.8, 4.1)

3.2 (3.1, 3.3)

Microbiology

3.1 (2.9, 3.4)

3.0 (2.1, 3.8)

4.2 (3.5, 5.0)

3.6 (3.0, 4.2)

3.7 (3.3, 4.1)

3.9 (3.7, 4.1)

Physiotherapy

0.7 (0.6, 0.7)

4.9 (4.2, 5.7)

3.5 (3.2, 3.9)

2.7 (2.6, 2.9)

2.1 (2.0, 2.1)

1.0 (1.0, 1.1)

The percentages do not add up to 100 %. We were unable to report specialties with low health care utilization

38

C么t茅 P et al

A selection of published research by CMCC faculty

Compared to baseline, the first 4 weeks following the claim were associated with a 534.3 % increase in the average number of services provided by general practitioners and family physicians. These medical services contributed 51.1 % of the total service usage for that period. During the first 4 weeks on benefits, injured workers increased their utilization of chiropractic and physiotherapy services by 318.6 % and 700.0 % respectively. Chiropractic and physiotherapy services represented 5.5 % and 2.0 % of the overall utilization during the initial post-claim period.

In the second year following the claim, general practitioners and family physicians provided 10 % more services compared to the pre-claim period and contributed 36 % of the overall increase in health services. Within the same period, chiropractors and physiotherapists provided 7 % and 42.8 % more services than during the pre-claim period.

Most services directly reimbursed by the Workplace Safety and Insurance Board were provided by chiropractors, physiotherapists and general hospitals (Table 3). The sharp decrease in chiropractic utilization between the onset of the claim (14.3 services/1,000 claimants/day) and the 6 month follow-up (0.3 services/1,000 claimants/day) suggests that most chiropractic treatments ended within the first 6 months following claim. A similar pattern of utilization was observed for services provided by physiotherapists or in general hospitals.

Health Care Utilization by Diagnostic Category Prior to making a claim, most health care services accrued (including chiropractic and physiotherapy) by workers were related to accidents, musculoskeletal disorders, diseases of the respiratory system and mental health disorders (Table 4).

As expected, services related to musculoskeletal disorders and accidents were most common during the first year after the claim. However, we also observed an increase in the

Table 4 Cumulative rate of health care utilization per 1,000 workers per day in the first year post-claim stratified by diagnostic category Baseline average 95 % CI)

% of all services during baseline

Year-1 average 95 % CI)

% of all Year 1 services

% Change from baselinea

Infectious and parasitic disease

0.92 (0.87, 0.98)

1.52

0.84 (0.79, 0.89)

0.87

-8.74

Diagnostic category

Neoplasms

0.33 (0.29, 0.36)

0.53

0.62 (0.58, 0.67)

0.65

91.39

Endocrine, nutritional, metabolic diseases and immunity disorders

0.74 (0.69, 0.79)

1.22

0.83 (0.78, 0.88)

0.86

12.15

Diseases of blood and blood-forming organs

0.13 (0.11, 0.15)

0.21

0.08 (0.07, 0.10)

0.08

-36.16

Mental disorders

2.94 (2.84, 3.03)

4.83

3.74 (3.64, 3.84)

3.88

27.44

Diseases of the nervous system and sense organs

2.46 (2.38, 2.57)

4.07

3.39 (3.26, 3.52)

3.51

36.9

Diseases of the circulatory system

1.57 (1.48, 1.65)

2.57

1.81 (1.72, 1.88)

1.87

14.93

Diseases of the respiratory system

3.68 (3.57, 3.79)

6.05

3.59 (3.49, 3.70)

3.72

-2.29

Diseases of the digestive system

1.76 (1.67, 1.85)

2.89

1.92 (1.83, 2.01)

1.99

9.26

Diseases of the genito-urinary system

1.79 (1.66, 1.83)

2.87

1.83 (1.74, 1.91)

1.89

4.61

Complications of pregnancy, childbirth and the peurperinium

0.27 (0.23, 0.30)

0.44

0.53 (0.47, 0.58)

0.54

98.27

Diseases of the skin and sub cutenaous system

1.28 (1.21, 1.35)

2.1

1.23 (1.17, 1.29)

1.27

-4.03

Diseases of the musculoskeletal system and connective tissue

3.48 (3.37, 3.59)

5.72

11.78 (10.78, 12.85)

12.2

238.66

Congenital anomalies

0.03 (0.02, 0.04)

0.05

0.04 (0.03, 0.05)

0.04

26.42

Perinatal morbidity and mortality

0.01 (0.00, 0.01)

0.01

0.01 (0.00, 0.01)

0

-11.11

Symptoms, signs and ill-defined conditions

0.55 (0.51, 0.59)

0.9

0.68 (0.63, 0.73)

0.71

24.48

Accident, poisoning and violence

3.53 (3.41, 3.65)

5.81

13.45 (11.19, 15.71)

13.93

280.75

Supplementary classification Without diagnosisb Chiropractic and physiotherapy

1.00 (0.94, 1.06)

1.65

0.98 (0.93, 1.04)

1.02

-1.71

29.41 (28.57, 30.26)

48.36

39.35 (37.90, 40.80)

40.77

33.79

5.00 (4.87, 5.12)

8.21

9.84 (9.49, 10.20)

10.19

97

Change rate = (Year 1 rate - baseline rate/baseline rate) * 100 Services without a diagnosis refer to visit for services where the submission of a diagnosis is necessary. These include imaging, laboratory testing and immunization a

b

39

CMCC Research Report 2012–2013

Table 5 Cumulative rate of health care utilization per 1,000 workers per day (95 % CI) in the second year post-claim stratified by diagnostic category Baseline average (95 % CI)

% of all services during baseline

Year 2 average (95 % CI)

% of all Year 2 services

% Change from baselinea

Infectious and parasitic disease

0.92 (0.87, 0.98)

1.52

0.77 (0.72, 0.83)

1.05

-16.23

Neoplasms

0.33 (0.29, 0.36)

0.53

0.81 (0.75, 0.86)

1.10

148.15

Endocrine, nutritional, metabolic diseases and immunity disorders

0.74 (0.69, 0.79)

1.22

1.06 (1.00, 1.12)

1.44

43.27

Diagnostic category

Diseases of blood and blood-forming organs

0.13 (0.11, 0.15)

0.21

0.11 (0.09, 0.13)

0.15

-12.50

Mental disorders

2.94 (2.84, 3.03)

4.83

3.76 (3.66, 3.86)

5.11

28.02

Diseases of the nervous system and sense organs

2.46 (2.38, 2.57)

4.07

2.78 (2.66, 2.89)

3.78

12.15

Diseases of the circulatory system

1.57 (1.48, 1.65)

2.57

2.02 (1.93, 2.10)

2.74

28.66

Diseases of the respiratory system

3.68 (3.57, 3.79)

6.05

3.57 (3.46, 3.68)

4.86

-2.92

Diseases of the digestive system

1.76 (1.67, 1.85)

2.89

1.95 (1.85, 2.05)

2.66

10.98

Diseases of the genito-urinary system

1.79 (1.66, 1.83)

2.87

1.99 (1.90, 2.08)

2.71

14.01

Complications of pregnancy, childbirth and the peurperinium

0.27 (0.23, 0.30)

0.44

0.56 (0.52, 0.61)

0.77

112.96

Diseases of the skin and subcutenaous system

1.28 (1.21, 1.35)

2.10

1.32 (1.26, 1.38)

1.79

3.27

Diseases of the musculoskeletal system and connective tissue

3.48 (3.37, 3.59)

5.72

6.19 (6.03, 6.35)

8.42

78.01

Congenital anomalies

0.03 (0.02, 0.04)

0.05

0.03 (0.02, 0.04)

0.04

1.89

Perinatal morbidity and mortality

0.01 (0.00, 0.01)

0.01

0.01 (0.01, 0.02)

0.02

144.44

Symptoms, signs and ill-defined conditions

0.55 (0.51, 0.59)

0.90

0.66 (0.61, 0.70)

0.89

20.19

Accident, poisoning and violence

3.53 (3.41, 3.65)

5.81

5.11 (4.96, 5.25)

6.94

44.52

Supplementary classification

1.00 (0.94, 1.06)

1.65

0.96 (0.90, 1.01)

1.30

-4.40

29.41 (28.57, 30.26)

48.36

33.67 (32.79, 34.56)

45.8

14.48

5.00 (4.87, 5.12)

8.21

6.19 (6.04, 6.35)

8.43

24.01

Without diagnosis

b

Chiropractic and physiotherapy

Change Rate = (Year 2 rate - baseline rate/baseline rate) * 100 Services without a diagnosis refer to visits for services where the submission of a diagnosis is necessary. These include imaging, laboratory testing and immunization a

b

number of services for: neoplasms; mental disorders; diseases of nervous systems and sense organs; diseases of the circulatory system; and for diagnoses reported as ‘‘symptoms, signs and ill-defined conditions’’ (Table 4). Finally, the number of services without a diagnosis increased during the first year following the claim. This increase is related to imaging and laboratory tests services.

Although it was significantly reduced compared to the first year of follow-up, the proportion of services related to musculoskeletal disorders (including chiropractic and physiotherapy) and accidents was still higher during the second year of follow-up than during the year that preceded the claim (Table 5). However, we also observed a sustained increase in the rate of services for: neoplasms; endocrine, nutritional, metabolic diseases and immunity disorders; mental disorders, diseases of nervous systems and sense

40

organs; diseases of the circulatory system; and for diseases of the genito-urinary system (Table 5).

Discussion We found that being sick-listed for neck pain is associated with a long-term increase in the utilization of health care services.

The sustained long-term increase in health care utilization is attributable to 8 % and 6 % of claimants respectively one and 2 years after the claim. In our cohort, the pre-claim rate of health care utilization was stable and peaked on the day the claim was initiated. Although the utilization of health care services decreased gradually thereafter, it did not return to its pre-claim level.

Our study has limitations. First, we were unable to link the data for the entire cohort. Compared to claimants without linked data, our sample (claimants with linked data) was

Côté P et al over-represented with males and claimants who were on benefits for more than 90 days. Therefore, it is possible that we analyzed a cohort with a disproportionately high number of injured workers with serious injuries or complicated claims. Second, we created our cohort using administrative data. Although we used code combinations that have a high positive predictive value (88.2 %) to identify claimants with neck pain, it is possible that we also included claimants with other disorders. Third, it is possible that we underestimated the number of post-claim services to physicians because it is likely that some workers received medical care from occupational physicians who are salaried by employers. Similarly, we were unable to capture services to physiotherapists or chiropractors that were reimbursed by other insurance programs or laboratory or imaging services provided in hospitals. Fourth, we cannot rule out the presence of misclassification on the coding of health care services from the Workplace Safety and Insurance Board and Ontario Health Insurance Plan databases. Finally, our data represents the health care utilization of injured workers who made a claim in 1997 and 1998. It is likely that the management of workrelated neck pain has evolved since that period which may limit the generalizability of our results.

Our results support the findings of Koehoorn et al. who previously reported a long-term increase in health care utilization in British Columbia hospital workers who filed a claim for musculoskeletal disorders [6]. In contrast to Koehoorn et al., our cohort did not have a gradual increase in utilization in the year leading up to the claim [8]. It is possible that the nature of the injuries in the British Columbia cohort was different from the occupational injuries experienced by our cohort. In addition, the British Columbia cohort included a wide range of musculoskeletal disorders while we focused on injured workers with neck pain. Our results suggest that most neck injuries may have been acute in nature. The difference between these two studies may also be attributable to differences in the study population.

The British Columbia cohort was restricted to injured health care workers while our cohort included all claimants to the Workplace Safety and Insurance Board (13.5 % were health care workers) [4, 8].

On January 1, 1998, the Ontario government introduced a new workers’ compensation law to facilitate return-to-work [10]. The Workplace Safety and Insurance Board also started to use nurse case managers to coordinate the delivery of health care services to injured workers. Relative to 1997, this change was associated with a reduction (6 months after the claim) in health care utilization for workers who made a

A selection of published research by CMCC faculty

claim in 1998. Although we cannot infer that the reduction is attributable to the legislative change, the similarity between the 1997 and 1998 cohorts suggest that it is a plausible explanation that warrants further investigation.

We observed a sustained increase in the utilization of medical, physiotherapy and chiropractic services postclaim.

It is possible that this increase is related to the recurrent and persistent nature of neck pain [6, 7]. However, as evidenced by the increase rate of utilization of pathology, diagnostic radiology and microbiology services, it is possible that the Workplace Safety and Insurance Board claim served as a doorway into the medical system and led to the investigation of other health conditions. It is also supported by the increase in number of health care services for comorbidities such as neoplasms; endocrine, nutritional, metabolic diseases and immunity disorders; mental disorders; diseases of the circulatory system; and diseases of the genito-urinary system.

We found a long-term increase in the average number of health care services utilized by injured workers who make a workers’ compensation claim involving neck pain.

It is important to note that this increase is attributable to between 6 % and 8 % of claimants. The increase may prove to be beneficial to the health of injured workers if it is associated with the diagnosis and management of health conditions that would otherwise have remained undiagnosed. However, our observation deserves validation. Moreover, further research to understand the relationship between making a workers’ compensation claim for neck pain and a long-term increase in health care utilization is warranted. The generalizability of our results may be restricted to jurisdictions with a similar no-fault workers’ compensation system and a universal health care system.

Acknowledgments This study was funded through a grant of The Ontario Ministry of Health and Long-Term Care (Special Chiropractic Research Fund). Dr. Côté was supported by the Canadian Institute of Health Research through a New Investigator Award. Dr. Kristman was supported by a Doctoral Training Award from the Canadian Institutes of Health Research in partnership with the Canadian Institute for the Relief of Pain and Disability’s (formerly the Physical Medicine Research Foundation) Woodbridge Grants and Awards Program and by the Institute for Work & Health by the Workplace Safety and Insurance Board of Ontario. Finally, we thank Dr. Dorcas Beaton for her scientific advice.

41

CMCC Research Report 2012–2013

References 1. Côté P, van der Velde G, Cassidy JD, Carroll LJ, HoggJohnson S, Holm LW, Carragee EJ, Haldeman S, Nordin M, Hurwitz EL, Guzman J, Peloso PM. The burden and determinants of neck pain in workers. Results of the bone and joint decade 2000–2010 task force on neck pain and its associated disorders. Spine. 2008; 33(4):S60–74.

2. Palmer KT, Walker-Bone K, Griffin MJ, et al. Prevalence and occupational associations of neck pain in the British population Scandinavian. J Work Environ Health.

2001;27:49–56.

3. Leroux I, Dionne CE, Bourbonnais R, Brisson C. Prevalence of musculoskeletal pain and associated factors in the Quebec working population. Int Arch Occup Environ Health. 2005;78:379–86.

4. Côté P, Kristman V, Vidmar M, Van Eerd D, HoggJohnson S, Beaton D, Smith PM. The prevalence and incidence of work absenteeism involving neck pain: a cohort of Ontario lost-time claimants. Spine.

2008;33(4s):s192–8.

5. Aronsson G, Gustafsson K, Dallner M. Sick but yet at work. An empirical study of sickness presenteeism.

J Epidemiol Commun Health. 2000;54:502–9. J Occup Rehabil 123 Author's personal copy 6. Carroll LJ, Hogg-Johnson S, Côté P, van der Velde G, Holm LW, Carragee EJ, et al. Course and prognostic factors for neck pain in workers: results of the bone and joint decade 2000–2010 task force on neck pain and its associated disorders. Spine. 2008;33(4):S93–100.

42

7. Van Eerd D, Côté P, Kristman V, Rezai M, Hogg-Johnson S, Vidmar M, Beaton D. The course of work absenteeism involving neck pain. A cohort study of Ontario lost-time claimants. Spine. 2011;36:977–82.

8. Koehoorn M, Cole DC, Hertzman C, Lee H. Health care use associated with work-related musculoskeletal disorders among hospital workers. J Occup Rehabil.

2006;342:1179–86.

9.

Statistics Canada. 2001 Census. http://www12.statcan.ca/ english/census01/products/standard/popdwell/tables.cfm.

10. Government of Ontario. Workplace Safety and Insurance Act, 1997. http://www.e-laws.gov.on.ca/html/source/ regs/english/2008/elaws_src_regs_r08035_e.htm.

11. Government of Ontario. Workers’ Compensation Act. 1994. http://www.e-laws.gov.on.ca/ html/repealedstatutes/english/elaws_ rep_ statutes_90w11_e.htm.

12. Van Eerd DV, Côté P, Beaton D, Hogg-Johnson S, Vidmar M, Kristman V. Capturing cases in workers’ compensation databases: the example of neck pain. Am J Ind Med. 2006;49: 557–68.

13. World Health Organization. Manual of the international statistical classification of diseases, injuries and causes of death, 9th Revision. Geneva: World Health Organization; 1977.

Originally published in the Journal of Occupational Rehabilitation, 2013, doi:10.1007/s10926-012-9415-8, Reprinted with permission from Springer Science + Business Media.

A selection of published research by CMCC faculty

Mechanobiology, Injury and Health

Assessing Bias in Studies of Prognostic Factors Hayden J1, Cartwright JL1, van der Windt DA 2, Côté P3, 4, 5 , Bombardier C6 Dalhousie University, 2Keele University, 3University of Ontario Institute of Technology, 4Canadian Memorial Chiropractic College, 5 University of Toronto, 6 Toronto General Hospital 1

Abstract Previous work has identified 6 important areas to consider when evaluating validity and bias in studies of prognostic factors: participation, attrition, prognostic factor measurement, confounding measurement and account, outcome measurement, and analysis and reporting. This article describes the Quality In Prognosis Studies tool, which includes questions related to these areas that can inform judgments of risk of bias in prognostic research. A working group comprising epidemiologists, statisticians, and clinicians developed the tool as they considered prognosis studies of low back pain. Forty-three groups reviewing studies addressing prognosis in other topic areas used the tool and provided feedback. Most reviewers (74%) reported that reaching

consensus on judgments was easy. Median completion time per study was 20 minutes; interrater agreement (κ statistic) reported by 9 review teams varied from 0.56 to 0.82 (median, 0.75). Some reviewers reported challenges making judgments across prompting items, which were addressed by providing comprehensive guidance and examples. The refined Quality In Prognosis Studies tool may be useful to assess the risk of bias in studies of prognostic factors.

Originally published in the Annals of Internal Medicine 2013;158(4):280-286. doi:10.7326/0003-4819-158-4201302190-00009. Reprinted with permission from the American College of Physicians.

Mechanobiology, Injury and Health

Towards Establishing an Occupational Threshold for Cumulative Shear Force in the Vertebral Joint — An In Vitro Evaluation of a Risk Factor for Spondylolytic Fractures Using Porcine Specimens Howarth SJ1, Callaghan JP 2 Canadian Memorial Chiropractic College, 2 University of Waterloo

1

Abstract Background Injury models for spondylolytic fracture of the pars interarticularis have long considered repetitive shear loading as a risk factor without quantifying the relationship between shear force magnitude and fatigue life. This investigation sought to quantify the relationship using a basic in vitro approach.

Methods Thirty-two (16 C3-C4, 16 C5-C6) porcine cervical specimens were exposed to repetitive shear loading to 20%, 40%, 60%, or 80% of their calculated ultimate anterior shear failure tolerance. Shear force was cyclically applied at 1Hz for 21,600 cycles or until bone failure was detected. Cumulative shear force and the number of cycles sustained until failure were calculated. Failure patterns were also documented.

43

CMCC Research Report 2012â&#x20AC;&#x201C;2013

Findings Cumulative shear and the number of cycles sustained prior to failure demonstrated a strong non-linearly decreasing relationship with increased force magnitude. In particular, sustained cumulative shear by the 40% group was 2.52 and 2.63MN*s higher than for the 60% and 80% groups (P<0.0001). Despite undergoing an average of 230 more loading cycles, cumulative shear force sustained by the 60% group was not statistically different from the 80% group. Bilateral fractures of the cranial vertebra's pars interarticularis were most common, but less consistent at higher force magnitudes.

Interpretation Our investigation suggested that pars interarticularis damage may begin non-linearly accumulating with shear forces between 20% and 40% of failure tolerance (approximately 430 to 860N). Models of pars interarticularis injury and estimates of cumulative shear exposure may be enhanced from a tissue-based weighting method for lowback shear.

Originally published in Clinical Biomechanics, 2013 Mar;28(3):246-54. doi: 10.1016/j.clinbiomech.2013.01.003.

Epub 2013 Jan 27. Reprinted with permission from Elsevier.

â&#x20AC;&#x201A; Mechanobiology, Injury and Health

Development of an Equation for Calculating Vertebral Shear Failure Tolerance Without Destructive Mechanical Testing Using Iterative Linear Regression Howarth SJ1, Giangregorio LM2, Callaghan JP 2 1

Canadian Memorial Chiropractic College, 2 University of Waterloo

Abstract Equations used to determine vertebral failure tolerances without the need for destructive testing are useful for scaling applied sub-maximal forces during in vitro repetitive loading studies. However, existing equations that use vertebral bone density and morphology for calculating compressive failure tolerance are unsuitable for calculating vertebral shear failure tolerance since the primary site of failure is the pars interarticularis and not the vertebral body. Therefore, this investigation developed new equations for non-destructively determining vertebral shear failure tolerance from morphological and/or bone density measures. Shear failure was induced in 40 porcine cervical vertebral joints (20 C3-C4 and 20 C5-C6) by applying a constant posterior displacement to the caudal vertebra at 0.15 mm/s. Prior to destructive testing, morphology

44

and bone density of the posterior elements were made with digital calipers, X-rays, and peripheral quantitative computed tomography. Iterative linear regression identified mathematical relationships between shear failure tolerance, and morphological and bone density measurements.

Along with vertebral level, pars interarticularis length and lamina height from the cranial vertebra, and inferior facet height from the caudal vertebra collectively explained 61.8% of shear failure tolerance variance. Accuracy for this relationship, estimated using the same group of specimens, was 211.9 N or 9.8% of the measured shear failure tolerance.

Originally published in Medical Engineering & Physics, 2013 Aug;35(8):1212-20. doi: 10.1016/j.medengphy.2012.12.009.

Epub 2013 Jan 20. Reprinted with permission from Elsevier.

A selection of published research by CMCC faculty

Mechanobiology, Injury and Health

Does Prolonged Seated Deskwork Alter the Lumbar Flexion Relaxation Phenomenon?

Howarth SJ1, Lee JGB1, Glisic D2, Beach TAC2 1

Canadian Memorial Chiropractic College, 2 University of Toronto

Abstract Sustained maximum lumbar spine flexion can increase the angle at which the low back flexion relaxation phenomenon (FRP) is observed. This adaptation has been hypothesized to have implications for the control of lumbar spine stability and increase the potential for low back injury. The objective of this study was to investigate if similar changes in the FRP would occur from sub-maximal spine flexion induced by an extended continuous duration of seated office deskwork. Twenty-three participants (12 male and 11 female) performed three bouts of full forward spine flexion interspersed with two 1-h periods of seated deskwork.

Lumbar spine angular kinematics and electromyographic activity from the lumbar erector spinae were obtained throughout all trials. The angles at which myoelectric silence occurred (FRP onset) were documented. Lumbar

flexion at FRP onset increased by 1.3 ± 1.5° after 1-h of sitting (p < 0.05) with no further increase after 2-h. However, when the angle at the FRP onset was normalized to the total range of flexion, there was no difference in the FRP onset.

These results suggest that the seated posture may induce residual deformation in the viscoelastic passive tissues of the low back; this could increase the challenge of controlling spine motion and reduce the load-bearing capacity of the lumbar spine system during activities performed following extended bouts of sitting.

Originally published in the Journal of Electromyography and Kinesiology, 2013 Jun;23(3):587-93. doi: 10.1016/j. jelekin.2013.01.004. Epub 2013 Feb 4. Reprinted with permission from Elsevier.

45

CMCC Research Report 2012–2013

Mechanobiology, Injury and Health

Viscoelastic Creep Induced by Repetitive Spine Flexion and its Relationship to Dynamic Spine Stability Howarth SJ1, Kingston DC2, Brown SH3, Graham RB2,4 1

Canadian Memorial Chiropractic College, 2 Queen’s University, 3 University of Guelph, 4 Nipissing University

Abstract Repetitive trunk flexion elicits passive tissue creep, which has been hypothesized to compromise spine stability. The current investigation determined if increased spine flexion angle at the onset of flexion relaxation (FR) in the lumbar extensor musculature was associated with altered dynamic stability of spine kinematics. Twelve male participants performed 125 consecutive cycles of full forward trunk flexion. Spine kinematics and lumbar erector spinae (LES) electromyographic (EMG) activity were obtained throughout the repetitive trunk flexion trial. Dynamic stability was evaluated with maximum finite-time Lyapunov exponents over five sequential blocks of 25 cycles. Spine flexion angle at FR onset, and peak LES EMG activity were determined at baseline and every 25th cycle.

Spine flexion angle at FR increased on average by 1.7° after

46

baseline with significant increases of 1.7° and 2.4° at the 50th and 100th cycles. Maximum finite-time Lyapunov exponents demonstrated a transient, non-statistically significant, increase between cycles 26 and 50 followed by a recovery to baseline over the remainder of the repetitive trunk flexion cycles. Recovery of dynamic stability may be the consequence of increased active spine stiffness demonstrated by the nonsignificant increase in peak LES EMG that occurred as the repetitive trunk flexion progressed.

Originally published in the Journal of Electromyography and Kinesiology, 2013 Aug;23(4):794-800. doi: 10.1016/j. jelekin. 2013.04.002. Epub 2013 May 1. Reprinted with permission from Elsevier.

A selection of published research by CMCC faculty

Interprofessional and Educational

Changes in Primary Care Physician’s Management of Low Back Pain in a Model of Interprofessional Collaborative Care: An Uncontrolled Before-After Study Mior S1,4 , Gamble B2,3, Barnsley J3, Côté P1,4, Côté E1 1

Canadian Memorial Chiropractic College, 2 Private practice, 3 University of Toronto, 4 University of Ontario Institute of Technology

Abstract Background Tracking how clinicians treat patients provides an opportunity to explore how the clinical management of common musculoskeletal disorders evolves over time. We present an uncontrolled before-after study of a primary care physician’s management of low back pain and describe how his involvement in an interprofessional collaborative practice was associated with a change in the management of patients with low back pain.

Method Data from the electronic medical record of one primary care physician who participated in a study of a model of chiropractic-medical collaboration were retrospectively collected. Records of a sample of consecutive patients prior to the start (i.e. pre-study, n = 51) and at the end of the collaborative study (i.e. study, n = 49) were collected.

Results Demographics were similar in both groups but median

number of physician visits (2.5 and 1.0), average prescriptions per patients (1.24 and 0.47), and total number of narcotic prescriptions (14 and 6) differed between pre-study and study groups, respectively.

Separate analysis of only the records of low back pain study patients revealed that 61% were referred for chiropractic care during the study period. Patients who were not referred had more neurological deficits and leg pain but back pain severity and average number of prescriptions was about the same. Referred patients in the study group had about 25% fewer physician visits and imaging requests.

Conclusion Based on this study of a single primary care physician, we hypothesize that doctors may change their prescribing behaviours and consultation rate for patients with low back pain when engaged in interprofessional collaborative care. Further research is required to test this observation in the population.

Introduction Chronic musculoskeletal conditions are a significant cause of disability and health care utilization [1, 2]. Côté et al. reported that 31% of people with low back or neck pain seek care from both physicians and chiropractors [3]. The nature of this care varies greatly across health care specialities. For example, patients with chronic musculoskeletal conditions who consult a physician and chiropractor take more medication than those who only consult a chiropractor [4]. But it is unknown if there was any level of interprofessional collaboration in the management of patients attending both health care providers.

However, evidence suggests that communication between

chiropractors and physicians is limited, which may foster fragmentation of care and impact its continuity and quality [5,6].

Evidence also suggests that a multidisciplinary approach to chronic conditions improves patient outcomes and patient and provider satisfaction [7-9]. Empirically, such improvement is founded on care being delivered by the appropriate health care provider with the greatest expertise for a given problem [10]. Health care providers working in primary care settings promoting collaborative practice, as in Family Health Teams (i.e. interprofessional collaborative health care teams delivering coordinated

47

CMCC Research Report 2012â&#x20AC;&#x201C;2013

quality care by various health care providers [11]), are well positioned to deliver such multidisciplinary care [12]. For instance, Kopansky-Giles et al. noted clinically important improvements in patients with musculoskeletal complaints who had access to chiropractic care in a hospital-based primary care setting [9].

We present a study of a primary care physicianâ&#x20AC;&#x2122;s management of low back pain and describe how his involvement in an interprofessional collaborative practice was associated with a change in his management of patients with low back pain.

Method Design This uncontrolled before-after study was nested in a two year observational study designed to evaluate the implementation of an interprofessional collaborative model [13].

The main observational study had as its objective to describe the implementation of a process-based model upon the professional relationship of chiropractors and primary care physicians, the continuity of patient care, the level of satisfaction of providers and patients, and the reimbursement of chiropractic services. The model involved strategies that addressed four key attributes of collaborative practice: communication (structured clinical notes, educational sessions, newsletters); defined musculoskeletal scope of practice; service delivery (no patient pay, provider capitated payments, access to diagnostic testing); and patient-centred care (patient choice, focus on prevention/ supportive care) [12,13]. Participants included primary care physicians, their patients and chiropractors.

Patients We formed two case series of consecutive patients with low back pain who presented before and after the implementation of the observational study to one of the study primary care physicians (physician) who belonged to a Family Health Team (FHT) in rural Ontario, Canada. Deidentified patient data were collected at two different points in time from the electronic medical record (EMR) of patients who presented with a chief complaint of low back pain (LBP).

The first case series included patients who consulted the primary care physician prior to the start of (i.e. pre-study

48

group) and the second included patients who were enrolled in the collaborative study (i.e. study group).

Data collection and outcome measures Information extracted from the EMR included the patientsâ&#x20AC;&#x2122; age, sex and patient-reported subjective rating of pain severity (on scale of 0 to 5, where 0 equated to no pain and 5 was worse pain ever). Our outcome measures included number of physician visits related to the presenting complaint, number and category of medications prescribed and clinical symptoms (location, neurological deficits, presence of co-morbidities).

All data were extracted using discrete patient identifiers and stored on an excel spreadsheet. Data were then entered into a statistical program (SPSS 14.0) and descriptively analyzed.

Ethics approval was obtained from the Canadian Memorial Chiropractic College and the University of Toronto.

Results There were 51 and 49 available LBP patient records extracted in the pre-study and study groups, respectively (see Table 1). The age of the patients and severity of LBP were similar in the two groups; however, there were more females in the pre-study group. The average number of physician visits during both time periods was about the same but the median number of visits was fewer in the study group compared to the pre-study group.

Table 2 summarizes the number and type of medications prescribed by the physician to patients in each group. There were twice as many patients in the pre-study group who were prescribed medication compared to the study group. Almost 33% of patients in the pre-study group were concurrently prescribed a second, and 4% a third medication, compared to 6% of patients in the study group who received only a second prescription. Despite the similarity in recorded pain severity, there were about 2.6 times more medications prescribed in the pre-study group compared to those in the study group.

There were more patients in the pre-study group who received prescriptions for either an NSAID or a Cox 2 inhibitor compared to the study group. Of note, for those receiving a second medication, there was a greater percentage in the pre-study group receiving a narcotic prescription. There were about twice the number of narcotic prescriptions provided to patients in the pre-study group as in the study group.

Mior S et al

A selection of published research by CMCC faculty

Table 1 A descriptive summary of variables extracted from the EMR comparing pre-study and study patients EMR selected variable

Pre-study

Study

51

49

Number of females (%)

27(53)

21 (43)

Mean patient age (sd)

59 (17.6)

59 (13.6)

2 of 5

2 of 5

44 (86.3

21 (43.9)

63

24

1.24 (0.71)

0.47 (0.62)

132

101

2.6 (1.3)

2.1 (1.6)

2.5 (5)

1.0 (6)

Number of cases

Severity of presenting condition (median) Number patients prescribed medication (%) Total number of medications prescribed Average number of prescriptions (sd) Total number of patient visits Average number of physician visits (sd) Median number of physician visits (range)

Table 2 Summary of the categories and the number of medications prescribed to patients in both groups Category

Pre-study group (n=51)

Study group (n= 49

Drug 1

Drug 2

Drug 3

Drug 1

Drug 2

Drug 3

12 (23.5)

2 (3.9)

0

8 (16.3)

1 (2.0)

0

7 (13.7)

6 (11.8)

1 (2.0)

5 (9.8)

1 (2.0)

0

Cox 2

12 (23.6)

1 (2.0)

0

6 (12.2)

1 (2.0)

0

SSRI

7 (13.7)

2 (3.9)

0

2 (4.1)

0

0

Other

6 (11.8)

6 (11.8)

1 (2.0)

0

0

0

Total

44 (86.3)

17 (33.3)

2 (3.9)

21 (42.9)

3 (6.1)

0

NSAID n (%) Narcotic

Table 3 shows that the physician referred 61% of patients in the study group for chiropractic services compared to none in the pre-study group. The sex, age and severity of pain of the study patients who were referred were similar to those who were not referred for chiropractic services. A greater percentage of the study group patients who were not referred for chiropractic care had more distal leg radiations and neurological deficits than those who were referred. Study patients who were referred by the physician to the chiropractors also had fewer co-morbidities but the nature of the co-morbidities (e.g. diabetes, depression, cardiovascular disease, rheumatoid arthritis) were about the same as in the not-referred study patients. More patients in the study group who were referred to a chiropractor were prescribed medications but the overall average number of

prescription medications was about the same as in the nonreferred group. The majority of medications prescribed were NSAIDs and Cox-2 inhibitors. Narcotics were prescribed in about 14% of the patients who were referred for chiropractic services and about 43% who were not referred. Patients referred for chiropractic services had almost 24% fewer physician visits. About 25% fewer patients in the study group who were referred for chiropractic care had imaging compared to the non-referred group.

Discussion We observed significant changes in the primary care physicianâ&#x20AC;&#x2122;s clinical management of patients with low back pain following his involvement in an interprofessional model of collaborative care. The physician prescribed

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CMCC Research Report 2012â&#x20AC;&#x201C;2013

Table 3 Summary of variables from the EMR of study patients who attended for care during the study EMR selected variable

Not referred

Referred to chiropractor

19

30

9 (47)

12 (40)

60 (16.3)

58 (11.7)

Severity of presenting condition (median)

2 of 5

+

2 of 5 +

Low back pain +/â&#x2C6;&#x2019; buttock pain (%)

5 (26)

24 (80)

Low back pain + leg radiations (%)

9 (47)

5 (17)

Presence of neurological deficits

11 (58)

12 (40)

Presence of co-morbidities (%)

12 (63)

13 (43)

Medication was prescribed (%)

7(37)

14 (47)

0.42 (0.61)

0.50 (0.63)

2.6 (2.0)

1.8 (1.1)

14 (74)

15 (50)

Number of cases Number of female cases (%) Mean patient age (sd)

Average number of prescriptions (sd) Average number of physician visits (sd) Imaging was requisitioned (%)

(+ Severity graded between 0 and 5, where 5 was most severe.).

fewer medications to study patients compared to prestudy patients, yet the patients had similar pain severity. This difference may have been related to the physicianâ&#x20AC;&#x2122;s participation in the collaborative model of care that facilitated patient access and choice to an alternative treatment modality, as well as to the educational sessions that highlighted evidence based care and LBP guidelines.

A study conducted by Bishop et al. provides some support for the use of a multi-modal guidelines-based plan in treating low back pain [14]. They compared the outcomes of multi-modal guidelines-based care, which included a chiropractor delivering manipulative care, to that of primary care physician-directed usual care. Interestingly, the use of narcotic analgesic medications was 78% in the usual care group, compared to 0% in the multi-modal group. Despite this difference in medication use, improvement in bodily pain was comparable between the two groups. However, they found the guideline-based multimodal treatment to be associated with significantly greater improvement in condition-specific functioning. This appears to support our results that patients seeing both a chiropractor and a primary care physician in an evidence based collaborativelike setting use less medication.

The study group patients who were referred by the physician for chiropractic care had fewer physician visits than nonreferred patients, the latter having the same average number of visits as the pre-study group. However, the non-referred study patients tended to have more radiating pain and

50

neurological deficits, suggesting a more complicated condition that could possibly explain the greater number of physician visits. It is possible that the physician was pre-selecting patients for chiropractic referral based on his experience participating in the study or applying evidence based care.

Patients in the study group, who were referred, had fewer subsequent primary care physician visits suggesting a possible opportunity for primary care physicians to see other patients, thus decreasing their wait lists. The visits to the chiropractor were not tracked and hence the overall impact of the referral on the health care system was not considered.

Previous studies have suggested that socioeconomic factors, such as employment, play a significant role in the use of prescription medications and alternative treatments [15,16]. Recently, opioid use among socioeconomically disadvantaged patients in Ontario has increased substantially [17]. Similarly, patients using opioids were more likely to be unemployed, implying economic disadvantage [18]. As well, higher socioeconomic status was found to be related to decreased use of analgesics and sedatives [16]. The authors suggested that a reason for the difference in medication use was that such patients could afford paying for alternative therapies. Participating in a collaborative model of care with access to no cost alternative therapy appeared to decrease the frequency of prescribing regardless of whether the patient was referred.

This decrease could have been attributed to increased primary care physician choice to access alternative care,

Mior S et al

more discriminating prescription use of medications by the primary care physician, or simply primary care physician involvement in the study, which allowed patient referral without considering ability to pay for chiropractic services.

The decreased use of medications in patients referred for chiropractic services has been reported previously [19-21]. Rhee et al. conducted a retrospective study using administrative claims data from a sample of 13,670 LBP patients [20]. They reported patients seeing a chiropractor were found to be less likely to use narcotic medications, supporting a previous finding that chiropractic care could be used as “a substitute treatment to pain medication and other health care services in patients with LBP” [20: 2610].

Finally, studies have reported that patients with chronic musculoskeletal conditions tend to visit physicians and chiropractors, and take more medications than patients seeing only a chiropractor [3,4]. It may be that such visits to both providers occurred with limited interprofessional collaboration. The findings reported herein suggest that patients with musculoskeletal conditions whose physician participated in a collaborative model of care were prescribed fewer medications, frequently referred to another health care provider, and had fewer physician visits. Also, fewer patients were prescribed two and three medications for low back pain, thus decreasing potential drug-drug interactions. This is important because approximately one third of patients taking opioids for chronic low back pain are at an increased risk of an adverse drug-drug interaction [22]. Furthermore, this enhanced level of interprofessional collaboration led to greater communication between providers and improved continuity of care, i.e. care delivered in a coordinated and timely manner [23]. These findings raise interesting questions about how interprofessional collaborative care can change provider behaviour and influence the overall utilization of health care resources and quality of care.

Evidence suggests improving patient care depends partly on the ability of health care providers to change their behaviour [24]. The application of a particular behaviour change theory may provide understanding of the array of factors that influence such change. The theory of planned behaviour hypothesizes that an individuals’ perceived control over, and their intention to perform a behaviour are determining factors to its engagement [25]. The strength of this intention is influenced by the attitudes and beliefs towards a particular behaviour, the normative beliefs, and motivation to comply. The physician in our study was a site champion, involved in planned site administrative and education

A selection of published research by CMCC faculty

meetings, and had previous interprofessional experience, variable factors that could influence intention and behaviour change. Further work may help inform how behavioural theory can influence interprofessional collaboration and enhance the delivery of quality patient centred care.

There are significant limitations to an uncontrolled before-after study. In our study, the data were extracted from a consecutive sample of patients from the EMRs of a single primary care physician who may have been biased due to his involvement in the study. As such, the results noted could also have been favourably confounded by the Hawthorne effect [26], where the physician’s behaviour was modified by their participation.

Although this is a fundamental concern with our selected study design, the noted observed changes in the number of medication prescriptions and the referral patterns of study patients suggests that the implementation of the collaborative model did have some influence upon the physician’s management of low back pain patients. In addition, coding bias or recording errors of various aspects of the patients’ visit and medication used may have occurred. However, the frequency of medication prescription and trend to decreased drug use are similar to previously reported larger studies.

Conclusion This uncontrolled before-after study suggests that interprofessional collaborative practice between primary care physicians and chiropractors, where patients were provided optional full access to chiropractic services, may influence primary care physician’s management of and prescribing pattern for patients with low back pain.

Further research is required to confirm such findings. If similar findings are found in a more robust study design, they may have important health policy implications related to collaboration in primary care, primary care physician workloads, and accessible health care.

Competing interests The authors declare that they have no competing interests.

Authors’ contributions SM and BG conceived the study, conceptualized the data and drafted the manuscript. JB and PC participated in its design and analyzed and interpreted the data. EC reviewed and summarized the literature and helped draft the manuscript.

All authors read and approved the final manuscript.

Acknowledgement This pilot study incorporates data collected from a study funded by the Primary Health Care Transition Fund (Grant # G03-05422), Ontario Ministry of Health and Long-Term Care.

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CMCC Research Report 2012–2013

References 1. Hawker G: Epidemiology of arthritis and osteoporosis. In Patterns of Health Care in Ontario: Arthritis and Related Conditions. Edited by Williams J, Badley EM. Toronto: Institute for Clinical Evaluative Sciences; 1998:1–10.

2. Von Korff M, Lin EH, Fenton JJ, Saunders K: Frequency and priority of pain patients’ health care use. Clin J Pain 2007, 23:400–408.

3. Côté P, Cassidy JD, Carroll L: The treatment of neck and back pain: Who seeks care? Who goes where? Med Care 2001, 39:956–967.

4. Hurwitz EL, Chiang L: A comparative analysis of chiropractic and general practitioner patients in North America: findings from the joint Canada/United States survey of health, 2002–03. BMC Health Serv Res 2006, 6:49. http://www.biomedcentral.com/1472-6963/6/49.

5. Mainous AG 3rd, Gill JM, Zoller JS, Wolman MG: Fragmentation of patient care between chiropractors and family physicians. Arc Fam Med 2000, 9:446–450.

6. Greene BR, Smith M, Allareddy V, Haas M: Referral patterns and attitudes of primary care physicians towards chiropractors. BMC Complement Altern Med 2006, 6:5. http://www.biomedcentral.com/14726882/6/5.

7. Garner MJ, Birmingham M, Aker P, Moher D, Balon J, Keenan D, Manga P: Developing integrative primary healthcare delivery: adding a chiropractor to the team.

Explore 2008, 4:18–24.

8. Maddison P, Jones J, Breslin A, Barton C, Fleur J, Lewis R, McSweeney L, Norgain C, Smith S, Thomas C, Tillson C: Improved access and trageting of musculoskeletal services in northwest Wales: trageted early access to musculoskeletal services (TEAMS) programme. BMJ 2008, 329:1325–1327.

9.

Kopansky-Giles D, Vernon H, Boon H, Steinman I, Kelly M, Kachan N: Inclusion of a CAM therapy (chiropractic care) for the management of musculoskeletal pain in an integrative, inner city, hospital-based primary care setting. J Alter Med Res 2010, 2:61–74.

10. Goldman J, Meuser J, Rogers J, Lawrie L, Reeves S: Interprofessional collaboration in family health teams.

Can Fam Physician 2010, 56:368–74.

11. Skolardis S, Oandasan I, Kimpton S: Family health teams: can health professionals learn to work together?

Can Fam Physician 2007, 53:1198–1199.

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12. Mior SA, Barnsley J, Boon H, Ashbury FD, Haig R: Designing a framework for the delivery of collaborative musculoskeletal care involving chiropractors and physicians in community-based primary care. J Interprof Care 2010, 24:678–689.

13. Mior S, Barnsley J, Boon H, Côté P, Gamble B, Haig R, Hayes R: Patient Outcomes in a Model of Interprofessional Patient-Centered Collaborative Practice. In-depth Case Study Design. In Proceedings of WFC’s 9th Biennial Congress and ECU’s 75th Anniversary Convention: 17–19 May 2007; Vilamoura.

Toronto: World Federation of Chiropractic; 2007:209– 212.

14. Bishop PB, Quon JA, Fisher CG, Dvorak MF: The Chiropractic Hospital-based Interventions Research Outcomes (CHIRO) study: a randomized controlled trial on the effectiveness of clinical practice guidelines in the medical and chiropractic management of patients with acute mechanical low back pain. Spine J 2010, 10:1055–1064.

15. Northcott HC, Bachynsky JA: Concurrent utilization of chiropractic, prescription medicines, non-prescription medicines and alternative health care. Soc Sci Med 1993, 37:431–435.

16. Haetzman M, Elliott AM, Smith BH, Hannaford P, Chambers WA: Chronic pain and the use of conventional and alternative therapy. Fam Pract 2003, 20:147–154.

17. Gomes T, Juurlink DN, Dhalla IA, Mailis-Gagnon A, Paterson JM, Mamdani MM: Trends in opioid use and dosing among socio-economically disadvantaged patients. Open Med 2011, 5:13–22.

18. Fitzcharles MA, Ste-Marie PA, Gamsa A, Ware MA, Shir Y: Opioid use, misuse, and abuse in patients labeled as fibromyalgia. Am J Med 2011, 124:955–960.

19. Vogt MT, Kwoh K, Cope DK, Osial TA, Culyba M, Starz TW: Analgesic usage for low back pain: impact on health care costs and service use. Spine 2005, 30:1075–1081.

20. Rhee Y, Taitel MS, Walker DR, Lau DT: Narcotic drug use among patients with lower back pain in employer health plans: a retrospective analysis of risk factors and health care services. Clin Ther 2007, 29:2603–2612.

21. Gurden M, Morelli M, Sharp G, Baker K, Betts N, Bolton J: Evaluation of a general practitioner referral service for manual treatment of back and neck pain. Prim Health Care Res Dev 2012, 30:1–7.

Mior S et al

22. Pergolizzi JV Jr, Labhsetwar SA, Puenpatom RA, Joo S, Ben-Joseph RH, Summers KH: Prevalence of exposure to potential CYP450 pharmacokinetic drug-drug interactions among patients with chronic low back pain taking opioids. Pain Pract 2011, 11:230–239.

A selection of published research by CMCC faculty

25. Walker AE, Grimshaw JM, Armstrong EM: Salient beliefs and intentions to prescribe antibiotics for patients with a sore throat. Br J Health Psychol 2001, 6:347–360.

23. Haggerty JL, Reid RJ, Freeman GK, Starfield BH, Adair CE, McKendry R: Continuity of care: multidisciplinary review. BMJ 2003, 327:1219–1221.

26. Grimshaw J, Campbell M, Eccles M, Steen N: Experimental and quasiexperimental designs for evaluating guideline implementation strategies. Fam Pract 2000, 17(Suppl 1):S11–16.

24. Michie S: Designing and implementing behaviour change interventions to improve population health. J Health Serv Res Policy 2008, 13(Suppl 3):64–69.

Originally published in Chiropractic and Manual Therapies, 2013 Feb 1;21(1):6. doi: 10.1186/2045-709X-21-6. Open access article. Reprinted with permission.

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CMCC Research Report 2012–2013

Mechanobiology, Injury and Health

Pain-Related Work Interference is a Key Factor in a Worker/Workplace Model of Work Absence Duration Due to Musculoskeletal Conditions in Canadian Nurses Murray E1, 2, Mustard C2, Franche RL 2, 3, 4, 8, Ibrahim S2, 8, Smith P 2, 8, Carnide N2, 8, Gibson J2, 9, Koehoorn M3, Côté P6, 8, 10, Guzman J7 Harvard School of Public Health, 2 Institute for Work & Health, 3 University of British Columbia, 4 Simon Fraser University, 5 Monash University, University of Ontario Institute of Technology, 7 University of British Columbia, 8 University of Toronto, 9 Knowledge Transfer & Exchange Consultant, 10 Canadian Memorial Chiropractic College 1 6

Abstract Objective To examine the role of pain experiences in relation to work absence, within the context of other worker health factors and workplace factors among Canadian nurses with workrelated musculoskeletal (MSK) injury.

Methods Structural equation modeling was used on a sample of 941 employed, female, direct care nurses with at least one day of work absence due to a work-related MSK injury, from the cross-sectional 2005 National Survey of the Work and Health of Nurses.

Results The final model suggests that pain severity and pain-related work interference mediate the impact of the following worker health and workplace factors on work absence

54

duration: depression, back problems, age, unionization, workplace physical demands and low job control. The model accounted for 14 % of the variance in work absence duration and 46.6 % of the variance in pain-related work interference.

Conclusions Our findings support a key role for pain severity and pain-related work interference in mediating the effects of workplace factors and worker health factors on work absence duration. Future interventions should explore reducing pain-related work interference through addressing workplace issues, such as providing modified work, reducing physical demands, and increasing job control.

Originally published in The Journal of Occupational Rehabilitation 2013 Jan 26. [Epub ahead of print]. Reprinted with permission from Springer Science + Business Media.

A selection of published research by CMCC faculty

â&#x20AC;&#x201A; Clinical Sciences

Self-Rated Disability, Fear-Avoidance Beliefs, Non-Organic Pain Behaviors are Important Mediators of Ranges of Active Motion in Chronic Whiplash Patients Vernon H, Guerriero R, Kavanaugh S, Soave D, Puhl A Canadian Memorial Chiropractic College

Abstract Abstract Purpose The influence of self-rated disability and fear-avoidance beliefs on whiplash sufferers in their performance of active ranges of motion has not been studied well. We undertook a cross-sectional study to determine this.

Methods Chronic whiplash subjects completed a standard clinical examination. They completed the Neck Disability Index (NDI), the Tampa Scale for Kinesiophobia (TSK) and pain visual analog scale (VAS). Active ranges of motion (goniometer) and cervical nonorganic simulation signs (C-NOSS) were obtained by the examiner. Univariate and multivariable analyses were conducted on these scores.

Results Sixty-four subjects (37 female) with a mean age of 41.4 (SD 16.1) years completed all scores. NDI, pain VAS and C-NOSS correlated significantly with ROM. In a multivariable model, only the NDI score contributed significantly to the variance of the ROM scores (14%). Conclusion: As chronic whiplash sufferers perform ROM in a clinical examination,

these ranges are importantly influenced by their selfperceived disability. Cervical nonorganic simulation signs can be helpful in distinguishing high from very high levels of disability and motion restriction. The lack of correlation with the TSK may present a challenge to the Fear Avoidance Model in whiplash. Implications for Rehabilitation Selfratings of disability in chronic whiplash sufferers are influenced by their fear-avoidance beliefs. While selfratings of disability are known to predict chronicity of whiplash, there is less known about how these ratings affect impairment assessment during recovery. This study shows that self-ratings of disability influence the presentation of impairment by chronic whiplash sufferers with respect to their ranges of neck motion. Signs of nonorganic behavior also influence ranges of motion and self-ratings of disability.

These findings should be incorporated into the interpretation of impairment findings in chronic whiplash sufferers in order to improve management.

Originally published in Disability and Rehabilitation, 2013 Apr 24. [Epub ahead of print]. Reprinted with permission from Informa Healthcare.

55

CMCC Research Report 2012–2013

Interprofessional and Educational

Assessing the Attitudes, Knowledge and Perspectives of Medical Students to Chiropractic Wong JJ1, Soave D 1, Di Loreto L 2, Kara A 2, Yu K 2, Mattia A 3, Weyman K 4, Kopansky-Giles D 1,5 1

Canadian Memorial Chiropractic College, 2 Private Practice, 3 University of Western Ontario, 4 University of Toronto, 5 St. Michael’s Hospital

Abstract Objective To assess second-year medical students' views on chiropractic.

Methods A three-step triangulation approach was designed, comprising a 53-item survey, nine key informant interviews and one focus group of 8 subjects. ANOVA was used to assess attituderesponse survey totals over grouping variables. Constant comparison method and NVivo was used for thematic analysis.

Results 112 medical students completed the survey (50% response rate). Subjects reporting no previous chiropractic experience/ exposure or interest in learning about chiropractic were significantly more attitude-negative towards chiropractic.

56

Thematically, medical students viewed chiropractic as an increasingly evidence-based complementary therapy for low back/chronic pain, but based views on indirect sources.

Within formal curriculum, they wanted to learn about clinical conditions and benefits/risks related to treatment, as greater understanding was needed for future patient referrals.

Conclusion The results highlight the importance of exposure to chiropractic within the formal medical curriculum to help foster future collaboration between these two professions.

Originally published in the Journal of the Canadian Chiropractic Association, 2013 Mar;57(1):18-31. Reprinted with permission.

A selection of published research by CMCC faculty

Conference Proceedings 2012-13 Erwin WM, Islam D, Eftekarpour E, Inman R, Fehlings M. Intervertebral disc-derived stem cells: Implications for regenerative medicine and neural repair. 11 Jun 14; Gothenburg, Sweden: ISSLS Annual Meeting.

Triano JJ. Differential Tissue Strain Estimation Across Strata of Lumbar Tissues Under Intrinsic Motion. 11 Oct 12; Arlington, TX: 10th International Tissue Elasticity Conference.

Kopansky-Giles D. Musculoskeletal Conditions – What are the differences across the globe? Rehabilitation. 11 Oct 14; Beirut, Lebanon: Bone and Joint Decade World Network Conference Beirut.

Triano JJ. Site of Care: A review of evidence and consensus process. 12 Jan 24; New York, NY: NYCC Research Symposium.

Arts J, Mei A, McManus E, Gleberzon B. The use of spinal manipulative therapy for pediatric health conditions: A systematic review of the literature. 12 Mar 17; ACC RAC Conference: 2012.

Dougherty P, Gleberzon B, Killinger L, Hawk C. Chiropractic Management of the Older Adult. 12 Mar 17; ACC RAC Conference: 2012.

Kopansky-Giles D. Advances in the management of back pain.

11 Oct 14; Beirut, Lebanon: Bone and Joint Decade World Network Conference Beirut.

Erwin WM, Islam D, Eftekarpour E, Inman R, Fehlings M. Intervertebral Disc-Derived Stem Cells: Implications for Regenerative Medicine and Neural Repair. 12 Mar 17; ACC RAC Conference: 2012.

Kopansky-Giles D. Closing the gaps – successful innovations and initiatives: World Spine Care. 11 Oct 16; Beirut, Lebanon: Bone and Joint Decade World Network Conference Beirut.

Gleberzon B, Lamarche G. Implementing Ethical Practice Management Concepts into Chiropractic College Curricula. 12 Mar 17; ACC RAC Conference: 2012.

Gooyers CE, McMillan RD, Howarth SJ, Eger TR, Callaghan JP. Impact of posture and prolonged vibration exposure on the low-back – an in vitro study. 11 Oct 18; London, ON: 42nd Annual Conference of the Association of Canadian Ergonomists.

Gleberzon B, Perle S, Lamarche G. Developing a model curriculum for ethical practice building at chiropractic colleges: opinions from an international workshop. 12 Mar 17; ACC RAC Conference: 2012.

Howarth SJ, Callaghan JP. Cumulative Shear Injury: Implications for Occupational Low-Back Injury Evaluation. 11 Oct 18; London, ON: 42nd Annual Conference of the Association of Canadian Ergonomists.

Huggins T, Luburic-Boras A, Gleberzon B, Popescu M, Bahry L. The use of the Activator Adjusting Instrument in the management of musculoskeletal disorders: A descriptive and systematic review of the literature. 12 Mar 17; ACC RAC Conference: 2012.

Vernon H. Upper Cervical Spine: Neurophysiologic considerations. 11 Oct 20; Norway: Norwegian Chiropractic Association Annual Convention.

Kinsinger S, Lawrence D. It's My Decision. Autonomy: Understanding How This Core Bioethical Principle Impacts Chiropractic Research, Education and Patient Care. 12 Mar 17; ACC RAC Conference: 2012.

Vernon H. Considerations of the upper cervical spine and its influence in older patients. 11 Oct 20; Norway: Norwegian Chiropractic Association Annual Convention.

Vernon H. Is kinematics useful for motion palpation of the upper cervical spine? 11 Oct 20; Norway: Norwegian Chiropractic Association Annual Convention.

Budgell BS. Neuroscience articles are largely incomprehensible - the results of a quantitative lexical analysis.

11 Nov 12; Washington, DC: Neuroscience 2011.

Budgell BS. Peripheral somatic stimulation mitigates ischemia in the rat spinal cord. (poster) 11 Nov 15; Washington, DC: Neuroscience 2011.

Kopansky-Giles D, Peranson J, Reeves S. Teaching an interprofessional approach to the management of musculoskeletal problems in primary care. A pilot study Part 1: Students. 12 Mar 17; ACC RAC Conference: 2012.

Kopansky-Giles D, Peranson J, Vernon H, Soave D. Development and evaluation of the Health Professional Collaborative Competency Perception Scale (HPCCPS). 12 Mar 17; ACC RAC Conference: 2012.

Laframboise M, Gringmuth R, Greenwood C. Kienbock's disease in a varsity football player: a case report and review of the literature. (poster). 12 Mar 17; ACC RAC Conference: 2012.

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CMCC Research Report 2012–2013

Lavigne V, Gleberzon B. The clinical effectiveness of ultrasound as a treatment for ductal blockage affecting optimal breastfeeding among 25 postpartum lactating women: a retrospective case series. (poster). 12 Mar 17; ACC RAC Conference: 2012.

Peranson J, Kopansky-Giles D, Reeves S. Teaching an interprofessional approach to the management of musculoskeletal conditions in primary care. A pilot project.

Part 2 – Educators. 12 Mar 17; ACC RAC Conference: 2012.

Piper S, Bozzo S, Bonar J, Meldrum D. Manipulation training and lumbar spine stability: An investigation using a modified prone instability test. (poster) 12 Mar 17; ACC RAC Conference: 2012.

Kumka M, Bonar J. Development of classifications and descriptions of fascia based on literature review. 12 Mar 28; Vancouver, BC: Third International Fascia Research Congress.

Erwin WM. Notochordal Cells Protect Nucleus Pulposus Cells From Degradation And Apoptosis: Implications For The Mechanisms Of Intervertebral Disc Degeneration. 12 Apr 26; Chicago, IL: 2012 Lumbar Spine Research Society.

Kopansky-Giles D. Teaching an Interprofessional Approach to the Management of Musculoskeletal Problems in Primary Care – A Pilot Study. (poster) 12 May 15; Portland, OR: 2012 International Research Congress on Integrative Medicine and Health.

Porr J, Laframboise M, Kazemi M. Traumatic hyoid bone fracture: a case report and review of the literature. (poster). 12 Mar 17; ACC RAC Conference: 2012.

Boon H, Mior S, Rozmovits L. Exploring the Safety Culture of Spinal Manipulative Therapy: Interviews with key informants and frontline practitioners. (poster) 12 May 15; Integrative Medicine and Health - International Research Congress; Portland, Oregon.

Quesnele J, Wells J, Wells G, Triano JJ, Noseworthy M, Rayner T. A novel technique for measuring changes in vertebral artery blood flow. 12 Mar 17; ACC RAC Conference: 2012.

Howard L. Walking the talk: Applying adult education principles to influence change. 12 May 28; Waterloo, ON: Canadian Association for Studies in Adult Education (CASAE) 2012.

Riva JJ, Busse JW, Wong JJ, Brunarski D, Chan AHY, Lobo RA, Aptekman M, Gupta A. Consideration of chronic pain in trials to promote physical activity for diabetes: a systematic review of randomized controlled trials. 12 Mar 17; ACC RAC Conference: 2012.

Wadey V, McDonald H, Kopansky-Giles D, Cividino A, Wessel J, Herold J, Archibald D. On-line vs paper format learning: identifying inflammatory arthritis early: Randomized control trial.

12 Jun 8; Ottawa, ON: Canadian Orthopaedic Association Meeting.

Sadr S, Soave D, Moss J, Mior S. Female Chiropractors in Ontario: Current Practice profiles and graduate demographics.

12 Mar 17; ACC RAC Conference: 2012.

Soave D, Mior S. Analysis of reported patient visit frequencies and costs from the patient management program database in Ontario. 12 Mar 17; ACC RAC Conference: 2012.

Wadey V, McDonald H, Kopansky-Giles D, Cividino A, Wessel J, Herold J, Archibald D. On-line vs paper format learning: identifying inflammatory arthritis early: Randomized control trial. (poster) 12 Mar 28; Vancouver, BC: Canadian Rheumatology Association's Annual General Meeting.

Wadey V, McDonald H, Kopansky-Giles D, Cividino A, Wessel J, Herold J, Archibald D. On-line case simulation versus paper format: The ability to screen for arthritis using GALS. (poster) 12 Jun 8; Ottawa, ON: Canadian Orthopaedic Association Meeting.

Cambridge EDJ, Triano JJ, Ross JK, Abbott MS. Spinal manipulation technique modifications affect force-time profiles. (poster) 12 Jun 9; Vancouver, BC: 17th biannual meeting of the Canadian Society of Biomechanics/Societe Canadienne de Biomechanique (CSB/SBC).

Tibbles A. Educational Theory in Teaching and Learning of Manual Skills in Chiropractic. 12 Sep 26; Perth, Australia: WFC Education Conference Translating Evidence into Practice.

Wadey V, McDonald H, Kopansky-Giles D, Cividino A, Wessel J, Herold J, Archibald D. On-line case simulation versus paper format: The ability to screen for arthritis using GALS. (poster) 12 Mar 28; Vancouver, BC: Canadian Rheumatology Association's Annual General Meeting.

Moss JA. Enhanced Learning of Manipulation Techniques Using Force-Sensing Table Technology (FSTT): Student vs Supervisor Perceptions of Skill Competence. 12 Sep 26; Perth, Australia: WFC Education Conference Translating Evidence into Practice.

Sovak G. Connective Tissue Infiltration and Subcutaneous Fat in Fascioscapulohumeral Muscular Dystrophy-Affected Biceps Brachii Muscle. 12 Mar 28; Vancouver, BC: Third International Fascia Research Congress.

Kopansky-Giles D, Sully M. Preparing chiropractic graduates to work effectively in mainstream health care settings. 12 Sep 26; Perth, Australia: WFC Education Conference Translating Evidence into Practice.

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A selection of published research by CMCC faculty

Howard L. Integrating Evidence Based Teaching (EBT) Strategies into Health Science Curricula. 12 Oct 24; Washington, DC: International Congress for Educators in Complementary and Integrative Medicine.

Pierre E, Howard L. Crossing boundaries: A visual conversation about education development. 13 Feb 20; Waterloo, ON: Education Developers Council (EDC) Conference, Wilfred Laurier University.

Howard L, Pierre E. Integrating theory and practice: Employing an emergent ID model to adapt face to face to online environments. 12 Oct 24; Hamilton, ON: International Society for the Scholarship of Teaching and Learning (ISSOTL) conference.

Lee A, Mok W, Siu K, Kwan H, Li L. Differences in clinical approach between dentists and chiropractors analyzing the same set of temporomandibular joint dysfunction cases. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Peranson J, Kopansky-Giles D. Teaching an Interprofessional Approach to Managing Low Back Pain in the Primary Care Setting. 12 Oct 24; Washington, DC: International Congress for Educators in Complementary and Integrative Medicine.

McManus E, Mior S. Impact of provincial subsidy changes on chiropractic utilization in Canada. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Peranson J, Kopansky-Giles D. Development and Evaluation of the Health Professional Collaborative Competency Perception Scale (HPCCPS). 12 Oct 24; Washington, DC: International Congress for Educators in Complementary and Integrative Medicine.

Triano JJ, Giuliano D, McGregor M, Howard L. Perceptions of Competence and Confidence: Student-Intern vs. FacultyClinician. 12 Oct 24; Hamilton, ON: International Society for the Scholarship of Teaching & Learning (ISSOTL) 2012.

Archibald D, Wadey V, McDonald-Blumer H, Cividino A, Levy D, Wessel J, Kopansky-Giles D, McIlroy J. Online case simulation versus paper format: the ability to screen for arthritis using GALS. Family Medicine Forum, Toronto, ON. November 15-17, 2012.

Wong JJ. Examining the relationship between theory-driven policies and allowed lost-time back claims in workers’ compensation: a system dynamics model. 12 Nov 29; Toronto, ON: Financial Incentives Symposium (FIS) 2012.

Starmer D, Morano R, Sweeney A, Miele P, Netley S. Does muscular strength and power of second year chiropractic students correlate with peak force-production during a maximal effort bilateral hypothenar contact manipulation: a pilot study. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Starmer D, Duquette S, Howard L. Participation strategies and student performance: a case study. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Stainsby B, Piper S. The impact of the 2012 Arctic Winter Games on athletes' health behaviors: a cross-sectional survey. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Grondin D, Triano JJ, Tran S. The effect of a semi-customized, dual-contoured pillow on muscle activation, posture and contact pressures of the head and neck. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Quesnele J, Triano JJ, Wells G. Changes in vertebral artery blood flow following various head positions and manipulation.

13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Starmer D, Duquette S, Giuliano D, Finn K, Miners A, Tibbles A. Does participating in a simulated cardiac arrest scenario, using high fidelity manikins, improve an interns’ technical emergency care skills: a case study. (poster) 12 Dec 5; Toronto, ON: SIMone’s annual Ontario Simulation Exposition.

Abboud J, Marchand A, Sorra K, Descarreaux M. Musculoskeletal physical outcome measures in individuals with tension-type headache: a review. (poster) 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Starmer D, Duquette S, Stainsby B. Does soft tissue compliance of thoracic para-spinal musculature change based on body type. 12 Dec 5; Toronto, ON: SIM-one’s annual Ontario Simulation Exposition.

Kanga I, Stern P, Giuliano D. Proximal tibiofibular ganglion cyst in a recreational runner: a case report. (poster) 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Howard L. Employing Evidence Based Teaching (EBT) Strategies to Create More Effective Learning Spaces. 13 Jan 13; Orlando, FL: Higher Education Teaching & Learning (HETL) Conference.

Lameris M, Schmidt C, Gleberzon B, Ogrady J. Attitudes towards vaccination: a follow up survey of students at the Canadian Memorial Chiropractic College. (poster) 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Howard L. Crossing boundaries, building capacity and effecting educational change: A case study. 13 Feb 20; Waterloo, ON: Education Developers Council (EDC) Conference, Wilfred Laurier University.

Malone S, Gleberzon B, Cerulli M, Osmond T. The use of social media among a random sample of Ontario chiropractors. (poster) 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

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CMCC Research Report 2012â&#x20AC;&#x201C;2013

Piper S, Walters J, Harris G. Acute spinal cord compression resulting in myelomalacia: a case report. (poster) 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Starmer D, Duquette S, Giuliano D, Finn K, Miners A, Tibbles A. Does participating in a simulated cardiac arrest scenario, using high fidelity manikins, improve an interns' technical emergency care skills: a case study? (poster) 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Kinsinger S. Continuing education for professionals on ethics and boundaries: a survey of the chiropractic profession. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Kinsinger S. A proposed bioethics curriculum for accredited chiropractic colleges. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Giuliano D, McGregor M. Feasibility study evaluating a checklist tool for simulation. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Starmer D, Duquette S, Stainsby B. Does soft tissue compliance of thoracic para-spinal musculature change based on body type. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Gleberzon B, Stuber K. Frequency of use of diagnostic and manual therapeutic procedures of the spine taught at CMCC: a preliminary survey of chiropractors. 13 Mar 14; Washington, DC: ACC RAC Conference 2013.

Boon H, Mior SA, Rozmovits L. Exploring the safety culture in spinal manipulative therapy: interviews with key informants.

International Society for Complementary Medicine Research 8th Annual Congress; London, UK, Apr 11-13, 2013.

Kazemi M, Hashemvarzi SA, Mohammadi ZF. The Combined Effect of Creatine and Sodium Bicarbonate Supplementation on Blood Lactate and Anaerobic Power in Young Taekwondo Players.

13 Apr 10; Durban, South Africa: FICS Assembly & Symposium.

Harris G, Tahir S, Rakkar A, Kang M. The Effects of InstrumentAssisted Soft-Tissue Mobilization (IASTM) and Sham Microcurrent Therapy (MT) on Hamstring Flexibility When Performed on the Plantar Fascia of Healthy Subjects: A Pilot

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Study. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Triano JJ. Identifying the site of care for manual treatment methods: what does the evidence say? 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Inoue N, Senoo I, Espinoza OrĂ­as AA, An HS, Andersson GB, Triano JJ. In Vivo Measurements of 3D Lumbar Foraminal Geometry. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Lishchyna N. Intrarectal spinal adjustments for traumatic coccydynia: a report of two cases. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Kopansky-Giles D. EBP in the Management of Chronic Spinal Pain. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Kopansky-Giles D, Chang YL, Glazier R, Ghatan K, Peranson J. PAASSPORT: Primary care Advanced Access Study - Spreading the Practice and Optimizing Interprofessional Resources and Treatment. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Kazemi M, Hashemvarzi SA, Mohammadi ZF. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Sovak G, McGregor M, Howard L. Study guide drawings, learning style and student performance. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Quesnele J, Triano JJ, Wells G. Changes in vertebral blood flow following various head positions and manipulation. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

Wong J, McGregor M, Mior SA, Loisel P. Examining the relationship between theory-driven policies and allowed losttime back claims in workers' compensation: A system dynamics model. 13 Apr 10; Durban, South Africa: World Federation of Chiropractic (WFC) Biennial Congress 2013.

The CMCC Research Report 2012-2013 is produced by the Division of Marketing and Communications.

Director: Mara Bartolucci Copyeditor: Shannon Clark Art Director: Dora Kussulas Designer: Ashley Hagen Contributors: Mark Fillery, Margaret McCallen To request a copy, contact the Division of Marketing and Communications at: Phone: 416 482 2340 Fax: 416 482 3629 Email: communications@cmcc.ca Canadian Memorial Chiropractic College 6100 Leslie Street, Toronto, ON, M2H 3J1 www.cmcc.ca Copyright 2013 Canadian Memorial Chiropractic College

Canadian Memorial Chiropractic College 6100 Leslie Street, Toronto, Ontario M2H 3J1 Telephone: 416 482 2340 www.cmcc.ca