Example: clinical gait analysis Cerebral Palsy

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1 TRAMA: Bruxelles (15 janvier 2008) "Motion analysis and clinics: why to set up a motion analysis lab". J. Duysens A gait lab to study more than gait Motor Control Laboratory Research Center for Movement Control and Neuroplasticity Dep. of Biomedical Kinesiology (FaBeR) K.U. Leuven, Belgium And : SMK-RDE, Nijmegen, The Netherlands Example: clinical gait analysis Cerebral Palsy

2 Nijmegen Motor Unit AMTI force plate SPLIT-BELT

3 EMG EMG stands for electromyography. It is the study of muscle electrical signals. Electrodes are placed on the skin overlying the muscle. Alternatively, wire or needle electrodes are used and these can be placed directly in the muscle. When EMG is acquired from electrodes mounted directly on the skin, the signal is a composite of all the muscle fiber action potentials occurring in the muscle(s) underlying the skin. These action potentials occur at somewhat random intervals so at any one moment, the EMG signal may be either positive or negative voltage. Individual muscle fiber action potentials are sometimes acquired using wire or needle electrodes placed directly in the muscle. Telemetric EMG

4 VICON Simi motion : digitale video TRAMA: Bruxelles (15 janvier 2008) "Motion analysis and clinics: why to set up a motion analysis lab". J. Duysens A gait lab to study more than gait Motor Control Laboratory Research Center for Movement Control and Neuroplasticity Dep. of Biomedical Kinesiology (FaBeR) K.U. Leuven, Belgium And : SMK-RDE, Nijmegen, The Netherlands

5 Project 1 Freezing in PD Anke Snijders Research question How to INDUCE freezing of gait on a treadmill? Obstacles Anke Snijders

6 Project 2: EM-SCI International Multi-Center study Project3: SPORTS injury nr 1 Peroneus REFLEXES Longus AS DEFENSE? Ankle sprains

7 PREVIOUS STUDIES: STANDING INVERSION 30 DEG. JOHNSON ET JOHNSON,1993 ISAKOV ET AL., 1986 Closer to real life 10 cm cm 50% inverting, 50 % non-inverting Grüneberg, Nieuwenhuijzen and Duysens, JPhysiol., cm cm 50% inverting, 50 % non-inverting Nieuwenhuijzen and Duysens, 2007 (JN, in press)

8 No inversion Project 4 Project 4: Falls/ Eurokinesis

9 Project 4: Eurokinesis Learn how to fall Project 5: Balance (Lars Oude Nijhuis/Bas Bloem)

10 Examples : postural responses Commissaris et al., 2002 Project 6 EXPECTED CONTACT ACTUAL CONTACT ANTICIPATION PASSIVE STIFFNESS REFLEX ACTUAL LOAD = EXPECTED LOAD

11 EXPECTED CONTACT ACTUAL CONTACT E R ANTICIPATION R PASSIVE STIFFNESS REFLEX O R ACTUAL LOAD < EXPECTED LOAD Lowering of support surface Lower visual field occluded Cadence standardized Infrared beam to detect expected foot contact Pressure plate detects touchdown Protocol Expected Level EL EL 1 EL 10 Unexpected Level Unexpected Down UL UL 1. UL 7-10 UD 1, UL 1. UL 7-10 UD 2, UL 1. UL 7-10 : UD } UD 10 Expected Down ED ED 1 ED 10

12 CONTROL subject HH 44 y EXPECTED CONTACT 90 ms ACTUAL CONTACT E R ANTICIPATION R PASSIVE STIFFNESS REFLEX O R ACTUAL LOAD < EXPECTED LOAD Young adults

13 Medial Gastrocnemius Actual HC Expected HC ED Medial Gastrocnemius Expected HC in UD (-90 ms) Actual HC UD ED Medial Gastrocnemius Actual HC N = 1 UD ED MGi N = Subtracted (UD-ED) Extra activation starting some 40 ms after passing through the expected contact level

14 -0.5 Similar responses are seen in the contralateral TA TA MG Ipsilateral Contralateral ms ms -0.5 HC HC Similar responses are seen in the contralateral TA TA MG Ipsilateral Contralateral ms ms HC HC Functional significance? 1 bin = 10 ms Hase and Stein, 1998

15 Do these fast responses depend on fast afferents? Experiments on adults -age-matched controls -hereditary motor and sensory neuropathy; HMSNIa Project 6: Hereditary motor and sensory neuropathy Why frequent falls? HMSNIa subjectrm 44y

16 RTA 1,6 1,1 0,6 HMSN 1a Healthy subjects 0,1-0, Onset latencies of the responses after expected contact were increased in the HMSNIa patient group Onset Latencies 140 * * * * * 120 Onset latency (ms) HMSN Healthy subjects 20 0 LTA LGM LRF LBF RTA RGM RRF RBF Co-workers: M. Van der Linden P.H.J.A. Nieuwenhuijzen V. Weerdesteyn C. Bastiaanse C. Grüneberg B. Smits-Engelsman G.P. van Galen, B. Nienhuis, B. Groen, R. Den Otter I. Schillings C. Hofstad

17 The End