Feasibility and reliability of using an exoskeleton to emulate muscle contractures during walking.
Contracture is a permanent shortening of the muscle-tendon-ligament complex that limits joint mobility. Contracture is involved in many diseases (cerebral palsy, stroke, etc.) and can impair walking and other activities of daily living. The purpose of this study was to quantify the reliability of an exoskeleton designed to emulate lower limb muscle contractures unilaterally and bilaterally during walking. An exoskeleton was built according to the following design criteria: adjustable to different morphologies; respect of the principal lines of muscular actions; placement of reflective markers on anatomical landmarks; and the ability to replicate the contractures of eight muscles of the lower limb unilaterally and bilaterally (psoas, rectus femoris, hamstring, hip adductors, gastrocnemius, soleus, tibialis posterior, and peroneus). Sixteen combinations of contractures were emulated on the unilateral and bilateral muscles of nine healthy participants. Two sessions of gait analysis were performed at weekly intervals to assess the reliability of the emulated contractures. Discrete variables were extracted from the kinematics to analyse the reliability. The exoskeleton did not affect normal walking when contractures were not emulated. Kinematic reliability varied from poor to excellent depending on the targeted muscle. Reliability was good for the bilateral and unilateral gastrocnemius, soleus, and tibialis posterior as well as the bilateral hamstring and unilateral hip adductors. The exoskeleton can be used to replicate contracture on healthy participants. The exoskeleton will allow us to differentiate primary and compensatory effects of muscle contractures on gait kinematics.
Willy Taillard Laboratory of Kinesiology, Geneva University Hospitals and Geneva University, Switzerland; HES-SO University of Applied Sciences and Arts Western Switzerland, School of Health Sciences, Geneva, Switzerland; Univ Lyon, Université Lyon 1, IFSTTAR, LBMC UMR_T9406, F69622, Lyon, France. Electronic address: Michael.attias@hcuge.ch.
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Attias
Willy Taillard Laboratory of Kinesiology, Geneva University Hospitals and Geneva University, Switzerland.
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Bonnefoy-Mazure
Pediatric Orthopaedic Service, Department of Child and Adolescent, Geneva University Hospitals and Geneva University, Geneva, Switzerland.
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De Coulon
Univ Lyon, Université Lyon 1, IFSTTAR, LBMC UMR_T9406, F69622, Lyon, France.
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Cheze
Willy Taillard Laboratory of Kinesiology, Geneva University Hospitals and Geneva University, Switzerland.
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Armand
D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002547:Cerebral Palsy / Q000503:physiopathology; D003286:Contracture / Q000503:physiopathology*; D000067190:Exoskeleton Device; D005240:Feasibility Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D020233:Gait Disorders, Neurologic / Q000503:physiopathology*; D006801:Humans; D035002:Lower Extremity; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D052097:Quadriceps Muscle; D015203:Reproducibility of Results; D020521:Stroke / Q000503:physiopathology; D013710:Tendons; D016138:Walking / Q000502:physiology*; D055815:Young Adult
contracture; emulation; exoskeleton; gait; kinematics; simulation