A Comparison Between Electromyography-Driven Robot and Passive Motion Device on Wrist Rehabilitation for Chronic Stroke

Abstract

Background. The effect of using robots to improve motor recovery has received increased attention, even though the most effective protocol remains a topic of study. Objective . The objective was to compare the training effects of treatments on the wrist joint of subjects with chronic stroke with an interactive rehabilitation robot and a robot with continuous passive motion. Methods. This study was a single-blinded randomized controlled trial with a 3-month follow-up. Twenty-seven hemiplegic subjects with chronic stroke were randomly assigned to receive 20-session wrist training with a continuous electromyography (EMG)-driven robot (interactive group, n = 15) and a passive motion device (passive group, n = 12), completed within 7 consecutive weeks. Training effects were evaluated with clinical scores by pretraining and posttraining tests (Fugl-Meyer Assessment [FMA] and Modified Ashworth Score [MAS]) and with session-by-session EMG parameters (EMG activation level and co-contraction index). Results. Significant improvements in FMA scores (shoulder/elbow and wrist/hand) were found in the interactive group ( P < .05). Significant decreases in the MAS were observed in the wrist and elbow joints for the interactive group and in the wrist joint for the passive group ( P < .05). These MAS changes were associated with the decrease in EMG activation level of the flexor carpi radialis and the biceps brachii for the interactive group ( P < .05). The muscle coordination on wrist and elbow joints was improved in the interactive groups in the EMG co-contraction indexes across the training sessions ( P < .05). Conclusions. The interactive treatment improved muscle coordination and reduced spasticity after the training for both the wrist and elbow joints, which persisted for 3 months. The passive mode training mainly reduced the spasticity in the wrist flexor.