Duration of EMG-triggered electrical stimulation treatment is not associated with upper extremity motor outcomes in subacute stroke.

Abstract

The primary objective was to determine the association between electromyography-triggered neuromuscular stimulation (E-nMES) treatment duration and: (a) change in paretic upper extremity (UE) motor impairment; and (b) change in UE functional outcomes. This was a secondary analysis of multicenter, randomized, controlled trial in which E-nMES was applied to 41 participants' paretic UE wrist and finger extensors. The prescribed dose was two, 40-minute sessions per day, occurring 5 days/week, over an 8-week period. E-nMES duration was recorded in minutes by the device. The Fugl-Meyer Upper extremity assessment (FMA) and Arm Motor Ability Test (AMAT) were administered before and one week after intervention completion. Duration of use over the intervention period was 2346.7 + 987.9 min (range = 173 - 3773 min). FM and AMAT scores increased significantly from baseline to end of intervention (FM {Z = -4.58, <i>p</i> < 0.001}; AMAT {Z = -4.41, <i>p</i> < 0.001}). However, no association was found between total duration of E-nMES use and changes at end of intervention (FM {ρ = -0.072; <i>p</i> = 0.65}; AMAT {ρ = 0.079; <i>p</i> = 0.62}). Electrical stimulation duration does not significantly affect movement outcomes, highlighting the need for prioritizing individualized treatment approaches over standardizing stimulation dose.