Therapy for Abnormal Muscle Synergies in Stroke Using the ULIX Low-Impedance Robot

Patients who suffer from stroke often experience synergistic movements that make completion of activities of daily living (ADL) difficult. Robotics is useful for therapy for these patients due to providing varying levels of assistance to complete tasks or promoting more efficient movements through targeted resistance. A 5 degrees of freedom upper extremity low impedance exoskeleton (ULIX) was developed for stroke therapy. Various therapy modes were tested with three chronic stroke patients with abnormal synergies. Increased support and assistance led to improved hand opening force and completion of tasks. EMG data had positive changes in the biceps and extensor digitorum. Targeted resistance to certain joints led to improved arm trajectories.