Related Experiment Video
Updated: Mar 17, 2026

Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation
Published on: September 13, 2015
Interleaved neuromuscular electrical stimulation: Motor unit recruitment overlap
Matheus J Wiest1, Austin J Bergquist2, Helen L Schimidt1,3
1Laboratory of Neurophysiology, Faculty of Physical Education and Recreation, 4-218 Van Vliet Complex, University of Alberta, Edmonton, Canada, T6G 2H9.
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.
Related Concept Videos
Motor Unit Stimulation
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
Motor Units
Motor units come in different sizes, with smaller units...
Motor Units
Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Neuromuscular Junction And Blockade
The Neuromuscular Junction

