Feasibility of a new soft ankle exoskeleton on people with dropfoot post-stroke

Dropfoot gait pattern during walking commonly persists after stroke and is often associated with muscle weakness and pathological muscle activation. Exoskeletons have demonstrated the potential to improve mobility in people with neurological conditions. We have developed a novel soft ankle exoskeleton and shown its ability to correct simulated dropfoot and excessive inversion in nondisabled people. In this study, we evaluate its feasibility in five persons with chronic stroke and dropfoot gait patterns. 3D gait analysis was performed in three conditions: walking with only shoes, with the exoskeleton unpowered, and powered. Foot and ankle kinematics and step length asymmetry were evaluated. The participants also reported satisfaction with QUEST 2.0 and a study-specific questionnaire. Compared with only shoes, the powered exoskeleton partially corrected dropfoot by increasing dorsiflexion angle and foot clearance height in swing, facilitating heel contact, neutralizing ankle inversion, and increasing step length symmetry slightly. The participants expressed satisfaction with the exoskeleton's effectiveness, though some comfort-related issues were identified. This feasibility study suggests that the exoskeleton prototype can improve dropfoot gait patterns and be accepted by individuals in the chronic stage after a stroke.