Gait analysis with A novel approach for clinical gait analysis
Outline 2
1.
Gait analysis − −
Introduction Measurement systems
2. RehaWatch® − − − −
System Measurement Parameter Examples
3. Studies 4. Conclusion
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – introduction 3
Gait − Walking represents the ordinary manner of locomotion − The human gait is a periodic and reliable cycle and follows basic patterns − Gait is suitable to evaluate the functionality of the musculoskeletal system − The gait cycle produces many information over a short time, which an observing person can‘t fully memorize − Thus, and the necessity of documentation led to the development of instrumented gait analysis
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - basics 4
Situation in European Clinics − Better - but more expensive treatments of patients are available (new technologies) − The structure of the society is changing – more elderly persons − So costs for treatment of patients are increasing dramatically − Pressure of insurances for quality examination is increasing − Patients want to get objective information for the results of the treatment – they pay for treatment − Tools for objective measurements for effects of the treatment are necessary Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - basics 5
Gait analysis is a very important issue in the rehabilitation of patients with different indications concerning gait
Focus Neurological Rehabilitation − Only in Germany more then 250.000 new patients per year with stroke – nearly 80% of these patients have disturbances in locomotion
Focus Orthopedic Clinics − Surgery of artificial knees and hips has very increased
Focus Geriatric Clinics Focus Pediatric Clinics
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - basics 6
3 Phases using objective measurement of locomotion 1. Help to make a decision for a certain kind of treatment (treatment intervention planning) 2. Documentation of results during and at the end of the treatment for insurances and patients 3. Helping to decide whether to continue or to finish a treatment (a pro when talking with the health insurances to extend the treatment)
Gait analysis with RehaWatch • Š Hasomed 2011
1. Gait analysis - basics 7
How we can describe gait? − Most popular scheme is published by J. Perry and colleagues of RLARC (California, USA)
Modified by Perry & Burnfield 2010
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - basics 8
Perry & Burnfield 2010, 10
Gait analysis with RehaWatch • Š Hasomed 2011
1. Gait analysis – problems in clinical use 9
− Visual gait observation underlies verifiable subjective influence. Every people has its own subjective gait. − During early stages of rehabilitation patients have many abnormalities (e.g. no detection of gait phases is possible) − Other parameters to quantify gait are necessary − Gait cycle provides too much information in short time to observe and memorize everything without device
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – observation vs. instrumented analysis 10
− Today in many rehabilitation centers subjective, visual gait observation by physician or therapist is most commonly used. Different scales for observing gait are available (e.g. Tinetti test, 6 Minute Walking Test). but the results are … … subjective … not accurate … hardly comparable
Therefore objective measurements of the gait are necessary. Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – assistive systems 11
− Over the time different gait assessment systems with different measurement methods were developed: − 3 D ultrasound systems (e.g. Zebris)
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – assistive systems 12
Optical marker based infrared systems (e.g. Vicon) or videobased systems (e.g. SIMI Motion)
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - basics 13
Such systems are − Cost intensive (20.000 to >100.000€) − special laboratory/ room necessary only for gait analysis − Special education necessary for therapist – no automatic analysis – markers must positioned very exact − Limited to a small observation area - no independent gait – the results do not show the actual movement − Mostly connected to a treadmill – no independent gait possible But : you can document the movement of the whole body Mostly used in research institutes – not for clinical use Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – assistive systems 14
Foot pressure systems (e.g. Medilogic) Only a small component of gait is documented – not movement but effected pressure Not used in rehabilitation. Mostly used for optimization of orthopedic shoes e.g. for diabetic patients.
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – clinical expectations 15
What do Clinics need? Clinical expectations regarding instrumented gait analysis: − − − − − − −
Objective and reliable data Fast and easy to use Economic Possibility of documentation of the treatment Therapy supervision Verification of therapeutic success Use in authentic situations
It should secure and establish high quality in daily gait therapy
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - inertial sensor based systems 16
Therefore a new generation of gait measurement with inertial sensors was developed by the German company HASOMED GmbH in close cooperation with clinical partners
System
Gait analysis with RehaWatch • Š Hasomed 2011
Outline 17
1.
Gait analysis − −
Introduction Measurement systems
2. RehaWatch® − − − −
System Measurement Parameter Examples
3. Studies 4. Conclusion
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch - Overview 18
− RehaWatch is a mobile, inertial sensor based gait analysis system. − Sensors attached to lateral ankle measure linear acceleration and angle velocity − Processing raw data leads on − Position of the foot on earth and at the air − Gait events, − Orientation in space
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch - Package 19
− 2 inertial sensors, one for each foot − Data logger for controlling the measurement and storing the collected data − foot holds in different sizes − USB flash drives − Power supply − Velcro straps − Software for PC on CD − User manual
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Mounting/ Preparation 20
− The Easy and fast preparation and operation takes 3-5 minutes only 1. Fix the foot holds to the shoes 2. Sensors mounted with the foot holds 3. Cables fixed with adjustable straps to the legs 4. Data logger fixed with a belt on the back 5. Cables connected to the logger 6. Start measurement
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch - Measurement 21
Place for Measurement: − Straight, even floor, e.g. clinic corridor − distance min. of 10m – better 15m 2 Markers at the floor
Measurement: − Start (3s) – walking – stop (3s) During measurement: − Patient uses regular but sturdy shoes − Patient walks with self selected speed − Allows use of walker or special aid device or help from therapists − The device controls the assessment and guides the user – useable by a nurse or assistant Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Analyse with PC-Software 22
After Measurement: − Transfer of measurement data to PC via USB flash device − Automatic analysis with PC-software − Calculates gait parameters for each step − Diagrams and visualization of parameters
− Runs on standard Windows-PC and allows full patient and measurement data management − Export and report functionalities − Compares the results with norm data of healthy people Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch - Parameters 23
− Time and space parameters − − − − −
Number of steps Stride duration Stride length Cadence Velocity
− Gait phases − Loading response, foot flat, pre swing, swing
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch - Parameters 24
− Kinematic parameters − Foot height -> − Circumduction − Angle ground-foot
− Special events − Forefeet first, early heel off
− Symmetry − For all bilateral parameters (e.g. stand phase)
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – report 25
Report for the documentation
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – norm data 26
− Software includes reference values for comparison measurements data with data of healthy subjects − −
Based on 1,860 healthy subjects (data collected together with Prof. Leuchte, Martin-Luther-University Halle-Wittenberg) Norm data are in dependency of age, body height and gender Ranges from 5 - 100 years and 1,18m – 2,06m body height
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch - Parameters 27
− Score based on reference values − Allows graphical and customizable one-view assessment in comparison with healthy subjects
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Therapy progression 28
− Provides an overview of the therapy progression for each gait parameter − Values from multiple measurements at different times
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Therapy progression 29
Progress in symmetry of gait
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Example 1 30
− 58 years old woman − Uses walker − Patient in a neurological rehabilitation center
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Example 1 31
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Example 2 32
− 27 years old man − Patient in a Chinese clinic
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Example 2 33
Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch – Example 2 34
Gait analysis with RehaWatch • © Hasomed 2011
Outline 35
1.
Gait analysis − −
Introduction Measurement systems
2. RehaWatch® − − − −
System Measurement Parameter Examples
3. Studies 4. Conclusion
Gait analysis with RehaWatch • © Hasomed 2011
3. Studies – Reliability/ Reference values 36
Performed by Prof. Leuchte/ Dr. Schwesig, Martin-Luther University Halle-Wittenberg, Germany Published in Gait & Posture 33 (2011): „ Inertial sensor based reference gait data for healthy subjects“, pages 673–678 Aim: − Obtain spatio-temporal gait parameters using a large cohort of healthy persons of all ages and to identify relationships between gait parameters and subject characteristics − Test of reliability
Gait analysis with RehaWatch • © Hasomed 2011
3. Studies – Reliability / Reference values 37
Methods − − − − −
1860 healthy subjects, 5-100 years Self selected walking speed 20m floor walking distance Own comfortable shoes 3 trials per subject
Results − Large database over complete life span − Base for RehaWatch reference data − Allows more precise evaluation of specific gait parameters, not only in comparison to age groups but also at specific time points throughout a person’s life span − RehaWatch is highly reliable
Gait analysis with RehaWatch • © Hasomed 2011
3. Studies - Validation 38
Performed by Prof. Smolenski, Dr. Derlien, University Jena, Germany, Department of Physiotherapy Published in Manuelle Medizin 2010: „Validation studies for new, innovative gait analysis system RehaWatch from Hasomed” Aim:
− Validation of RehaWatch in comparison with foot pressure measurement system “MediLogic” − Does normal or soft floor influence the results? Methods: − 51 healthy subjects (21 male, 30 female, age: 25 ± 5 years) − 15 to 20 steps per measurement with 3 trials each − Randomized measurement system order − Normal and soft floor Gait analysis with RehaWatch • © Hasomed 2011
3. Studies - Validation 39
Results
Strideduration (s)
− High correlation for spatio-temporal gait parameters − Pearson-correlation shows good results for normal and soft floor − Conclusion: “ From our point of view the new gait analysis system RehaWatch® is suitable for monitoring the course in the clinical routine.” (Derlien et al.)
Subjects Gait analysis with RehaWatch • © Hasomed 2011
3. Studies - Fatigue measurement 40
Pilot study „Long term analysis with RehaWatch“ performed by Dr. Röpke, University Magdeburg, Clinic for Orthopedics
Aim: − Determine the time at which the subject/ patients shows changes in gait-specific parameters − How can fatigue be identified and evaluated?
Methods: − 12 subjects from a senior sports group (5 male, 7 female, age: 64,75 ± 3,25 years) TEP group: 6 subjects with knee or hip TEP Test group: 6 subjects with no orthopedic intervention − Each subject walks 400m
Gait analysis with RehaWatch • © Hasomed 2011
3. Studies - Fatigue measurement 41
Results: − TEP group shows a significantly greater fatigue than the test group at 400m (left picture) − Decrease in dependant parameters cadence, stride duration and stride length. Symmetry of gait is different.
Minutes
Test group Gait analysis with RehaWatch • © Hasomed 2011
TEP group
Outline 42
1.
Gait analysis − −
Introduction Measurement systems
2. RehaWatch® − − − −
System Measurement Parameter Examples
3. Studies 4. Conclusion
Gait analysis with RehaWatch • © Hasomed 2011
43
Gait analysis with RehaWatch • © Hasomed 2011
4. Conclusion – take home messages RehaWatch 44
− Offers objective and reliable measurement of gait parameters − Easy and fast to use - measurement including preparation and analysis takes maximum 5 minutes − Usable everywhere, no specific gait-location necessary (10-15 m clinic floor) − Further equipment is not necessary (e.g. treadmill) − No influence on the gait by the system. Very small Sensors. Own shoes can be used. − Large accumulator capacity for several hours measurements − Automatic analysis of the data on PC. No special education necessary. − Patient data compared with norm data − Important for quality management and documentation of treatment − Cost effective System Gait analysis with RehaWatch • © Hasomed 2011
45
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - history 46
− Gait observation was first described by Aristoteles (384 - 322 BC) − First steps of scientific gait analysis were done by Boreli (1608 – 1679 AD) with the publication „de motu animalum“ − Modern scientific elaboration of gait mechanisms was formed by the brothers Weber in the 19th century − Most important milestone was led by Braune & Fischer with the first 3 D movement analysis (early 20th century)
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – assistive systems 47
− Comparison of different measurement methods in relation to the clinical rehabilitation relevance :
System
Foot Pressure
Video Based
Inertial Sensor
Optical infrared
Ultrasound
Cost
++
+
++
--
-
Capture volume
-
--
++
-
--
Accuracy
+
+
+
++
++
Usability
+
-
++
--
-
Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis - inertial sensor based systems 48
That’s why a new generation of gait measurement with inertial sensors was developed from a German company
System This technology combines the benefits of visual gait monitoring and instrumented gait analysis: − Provide objective, reliable and exact gait parameters − No place boundary (e.g. laboratory) – walking 15m on clinic floor − Easy and time saving to use – 5 minutes − Expansive equipment is not necessary (e.g. treadmill) − Large data capacity recording (number of steps) − If necessary, data can be recorded for up to 2 hours for long time observation Gait analysis with RehaWatch • © Hasomed 2011
2. RehaWatch - Sensors 49
− Inertial sensors = „use the inertia of mass for detection of motion“ − Each sensor consists of accelerometers and gyroscopes − Build as MEMS – Technology: electronic and mechanical elements on 1 silicon chip − 3-axis accelerometer − 3-axis gyroscope
Gait analysis with RehaWatch • © Hasomed 2011
3. Studies – Reliabilitation/ Reference values 50
− RehaWatch is highly reliable − Pictures below shows regression lines of corrected stride length for men (left side) and women (right side)
Men
Gait analysis with RehaWatch • © Hasomed 2011
Women
4. Conclusion / outlook - Future development directions 51
− 7-sensor system − Measuring ankle, knee and hip joint − Primary in sagittal plane, later also in coronal and transverse plane − Biomechanical model of lower body
− Therapy system − Supplements traditional therapy to recover gait − Online analysis − Real time feedback for patients and suggestions for improvement − Multiple training programs − Adjustable for each subject All these future developments are actually possible with RehaWatch Gait analysis with RehaWatch • © Hasomed 2011
1. Gait analysis – observation vs. instrumented analysis 52
− Instrumented gait analysis is traditionally used for surgical applications, rehabilitation and treatment intervention planning, because… … it provides detailed kinetic and kinematic parameters … the results are objective … the systems are reliable but the application is … … limited to laboratory use … cost intensive … time consuming Gait analysis with RehaWatch • © Hasomed 2011
3. Studies - Fatigue measurement 53
Results: − TEP group shows a significantly greater fatigue than the test group at 400m (left picture) − Decrease in dependant parameters cadence, stride duration and stride length − Test group has less deviation in symmetry (right picture)
m/s
Minutes
Test group Gait analysis with RehaWatch • © Hasomed 2011
TEP group