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

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.

Randomized controlled trial.

Outpatient clinic of a rehabilitation centre.

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.

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.

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.

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.