Upper limb loads during robotic assisted gait: A measuring system to guide training

Patients suffering from Spinal Cord Injury (SCI) can partially restore their walking function over ground and reduce of the secondary pathologies thanks to a frequent use of powered exoskeletons for robot-assisted gait. However, many of these devices require crutches to stabilize the body or to initiate the step. This could induce high loads on the shoulder joints, leading to shoulder pain and pathologies in SCI patients. This study presents a methodology to evaluate shoulder joints loads during robotic assisted gait, which was applied to an expert user of a Rewalk® exoskeleton. A pair of wireless instrumented crutches, designed by the authors[1], measure the crutches’ forces and movements. A simplified mechanical model of the patient is then simulated in OpenSim to perform both inverse kinematic and inverse dynamic analysis. Such a system could be applied during the initial training of new users, to help guide both patient and therapist towards an optimal usage of the exoskeleton.