Interleaved neuromuscular electrical stimulation: Motor unit recruitment overlap

Muscle Nerve. 2017 Apr;55(4):490-499. doi: 10.1002/mus.25249. Epub 2017 Jan 22.

Abstract

Introduction: In this study, we quantified the "overlap" between motor units recruited by single pulses of neuromuscular electrical stimulation (NMES) delivered over the tibialis anterior muscle (mNMES) and the common peroneal nerve (nNMES). We then quantified the torque produced when pulses were alternated between the mNMES and nNMES sites at 40 Hz ("interleaved" NMES; iNMES).

Methods: Overlap was assessed by comparing torque produced by twitches evoked by mNMES, nNMES, and both delivered together, over a range of stimulus intensities. Trains of iNMES were delivered at the intensity that produced the lowest overlap.

Results: Overlap was lowest (5%) when twitches evoked by both mNMES and nNMES produced 10% peak twitch torque. iNMES delivered at this intensity generated 25% of maximal voluntary dorsiflexion torque (11 Nm).

Discussion: Low intensity iNMES leads to low overlap and produces torque that is functionally relevant to evoke dorsiflexion during walking. Muscle Nerve 55: 490-499, 2017.

Keywords: NMES; interleaved; motor unit; neuromuscular electrical stimulation; recruitment overlap; twitch torque.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Electric Stimulation
  • Electromyography
  • Female
  • Humans
  • Linear Models
  • Male
  • Muscle Contraction / physiology*
  • Muscle, Skeletal / physiology
  • Neuromuscular Junction / physiology*
  • Recruitment, Neurophysiological / physiology*
  • Torque
  • Walking / physiology
  • Young Adult