Acute effects of multipath electrical stimulation in patients with total knee arthroplasty

Abstract

Objective: To compare maximal evoked torque, discomfort, and fatigue-related outcomes between multipath neuromuscular electrical stimulation (NMES) and conventional NMES of the quadriceps muscle in patients with total knee arthroplasty (TKA).

Design: Randomized, single-blind, crossover study with 2 experimental sessions (multipath NMES, conventional NMES).

Setting: Research laboratory.

Participants: Patients (N=20; mean age, 68y) 6 to 12 months after TKA surgery.

Interventions: None.

Main outcome measures: We quantified NMES-evoked knee extension torque at the maximally tolerated current intensity, self-reported discomfort, and fatigue induced by NMES intermittent contractions in both conditions.

Results: Compared with conventional NMES, multipath NMES resulted in higher evoked torque (33%, P<.001), lower discomfort scores (-39%, P<.001), and less quadriceps muscle fatigue (P=.034).

Conclusions: The use of multiple current pathways distributed to large electrodes allowed multipath NMES to generate stronger contractions and reduce discomfort and fatigue compared with conventional NMES. Therefore, multipath NMES has the potential to be more effective than conventional NMES.

Keywords: Electric stimulation; Muscle fatigue; Rehabilitation; Torque.