Effects of robotic therapy on motor impairment and recovery in chronic stroke.

OBJECTIVE To examine whether robotic therapy can reduce motor impairment and enhance recovery of the hemiparetic arm in persons with chronic stroke. DESIGN Pre-posttest design. SETTING Rehabilitation hospital, outpatient care. PARTICIPANTS Volunteer sample of 20 persons diagnosed with a single, unilateral stroke within the past 1 to 5 years, with persistent hemiparesis. INTERVENTIONS Robotic therapy was provided 3 times weekly for 6 weeks. Subjects able to reach robot targets were randomly assigned to sensorimotor or progressive-resistive robotic therapy groups. Robotic therapy consisted of goal-directed, planar reaching tasks to exercise the hemiparetic shoulder and elbow. MAIN OUTCOME MEASURES The Modified Ashworth Scale, Fugl-Meyer test of upper-extremity function, Motor Status Scale (MSS) score, and Medical Research Council motor power score. RESULTS Evaluations by a single blinded therapist revealed statistically significant gains from admission to discharge (P<.05) on the Fugl-Meyer test, MSS score, and motor power score. Secondary analyses revealed group differences: the progressive-resistive therapy group experienced nonspecific improvements on wrist and hand MSS scores that were not observed in the sensorimotor group. CONCLUSIONS Robotic therapy may complement other treatment approaches by reducing motor impairment in persons with moderate to severe chronic impairments.