Chronic stroke motor recovery: duration of active neuromuscular stimulation

Active neuromuscular stimulation is an effective behavioral intervention for motor recovery improvements after a stroke. However, the most effective active neuromuscular stimulation durations have not been determined. The present experiment investigated active stimulation durations (0, 5, and 10 s) coupled with bilateral movements on progress toward motor recovery in wrist and finger extension. Twenty-six stroke survivors with chronic hemiparesis were randomly assigned to the stimulation duration groups, and subjects completed 4 days of rehabilitation training over a 2-week period. Mixed design analyses of variance on the Box and Block scores, chronometric reaction times, and force modulation of the sustained muscle contraction task revealed distinct motor recovery improvements for both the 5 and 10 s stimulation duration groups in comparison to the 0 s duration control group. Further, the number of blocks moved by the 10-s duration group exceeded those moved by the 5-s duration group. In conclusion, the 5 and 10 s duration active stimulation/bilateral movement groups decreased residual motor dysfunctions that persisted beyond 12 months post stroke.