Electrical stimulation of the upper extremity in stroke: cyclic versus EMG-triggered stimulation

Objective: To compare the effect of cyclic and electromyography (EMG)-triggered electrical stimulation on motor impairment and function of the affected upper extremity in chronic stroke. Design: Randomized controlled trial. Setting: Outpatient clinic of a rehabilitation centre. Subjects and intervention: Twenty-two subjects in the chronic stage after stroke were randomly assigned to receive either cyclic (n = 11) or EMG-triggered electrical stimulation (n=11) of the wrist and finger extensor muscles for a six-week period. Outcome measures: The primary outcome measure was the Action Research Arm test (0-57 points) to assess arm function. Grip strength, Fugl-Meyer Motor Assessment and Motricity Index were secondary outcome measures. Assessments were made at the start of the treatment and after 4, 6 and 12 weeks. Results: Both groups improved on the Action Research Arm test. The group receiving cyclic stimulation improved by 2.3 points, and the group receiving EMG-triggered stimulation improved by 4.2 points. The difference in functional gain was not statistically significant. Differences in gain on the secondary outcome measures were not significant either, Conclusion: The present study did not detect a significant difference between EMG-triggered and cyclic electrical stimulation with respect to improvement of motor function of the affected arm in chronic stroke.