Low-dose, EMG-triggered electrical stimulation for balance and gait in chronic stroke

Although promising for the affected arm, evidence supporting efficacy of surface electromyographytriggered neuromuscular stimulation (ETMS) is equivocal. Furthermore, the optimal ETMS dosing for any impairment remains unknown.

To determine the impact of a low-dose (20 min/day) ETMS regimen on affected ankle movement, balance, and ambulation in a chronic stroke patient (>12 months post stroke) exhibiting no active, affected ankle movement.

Goniometry, the Berg Balance Scale (Berg), and an automated measure of ambulation (the GAITRite) were administered. The subject then used ETMS once every weekday in 20-minute increments during a 4-week period. One week after completing the ETMS regimen, the outcome measures were again administered.

After intervention, the subject exhibited 25 degrees of active ankle flexion and 17 degrees active ankle extension. He also exhibited a 6-point increase on the Berg, indicative of score increases on 5 of the 14 Berg items: standing unsupported (3 to 4), standing to sitting (2 to 3), retrieving an object from floor (3 to 4), turning to look behind (1 to 3), and turning 360 degrees (1 to 2). He also exhibited increased gait velocity, cadence, step length, and stride length. Functionally, the subject reported safer and more rapid walking and improved transfers.

Even though the maximum ETMS dosing remains unknown, it appears that 20 minutes/day is a minimum amount that produces functionally relevant motor, balance, and ambulation changes. A larger ETMS dosing and efficacy trial is now planned.