ORIGINAL RESEARCH article

Front. Hum. Neurosci.

Sec. Motor Neuroscience

Volume 19 - 2025 | doi: 10.3389/fnhum.2025.1629003

This article is part of the Research TopicEfficacy, Neuromechanisms, and Human-AI Interface Integration: Neural-Adaptation Training Paradigms for Sports and RehabilitationView all 5 articles

Dual 500-µs Wide Pulse Neuromuscular Electrical Stimulation Enhancing Sensorimotor Cortical Excitability

Provisionally accepted
Yun  ZhaoYun Zhao*Yanying  YanYanying YanXiaoling  ZhangXiaoling ZhangGuanghui  XieGuanghui XieRenqiang  YangRenqiang YangShuaidong  ZouShuaidong ZouFengmei  GaoFengmei GaoWencheng  SunWencheng Sun
  • School of Smart Health, Chongqing Polytechnic University of Electronic Technology, Chongqing, China

The final, formatted version of the article will be published soon.

Background: Neuromuscular electrical stimulation (NMES) is an effective tool to improve motor activation of patients with motor dysfunction. However, to enhance the cortical activities induced by NMES, the corresponding strategies should be carefully designed with optimal stimulation parameters. The aim of the present study is to investigate whether the pulse assignment with wide-pulse-based Variable Frequency Trains improves sensorimotor cortical excitability.Methods: A block-designed experiment was conducted with NMES delivering current to right biceps brachii muscle in nine healthy right-handed adults to evoke repetitive elbow flexion under similar kinetic parameters (p>0.05). A new NMES pattern with the combination of wide-pulse and Variable Frequency Trains (wDFT, variable-frequency trains with 2-let frequency train) was set to compare with other NMES patterns, i.e., variable-frequency trains with narrow-pulse (nVFT, 8-let frequency train), constant-frequency trains with narrow-pulse (nCFT, one pulse), and CFT with wide-pulse (wCFT, one pulse). The excitability levels of sensorimotor regions were investigated based on beta event-related desynchronization (ERD) analysis. cortical excitability 删除[赵云]: of subjects 删除[赵云]:Results: Although evoking similar elbow flexion movements, variable-frequency trains (VFT) could induce stronger cortical activities than constant-frequency trains (CFT). Moreover, the sensorimotor cortex responded significantly more preferably to the dual 500µs wide pulse VFT (wDFT) stimulation pattern (p<0.05). In general, VFT induced higher amplitudes and descending slopes of beta ERD than CFT did during evoking elbow flexion movements, among which wDFT induced the highest beta ERD intensity and its descending slope (p<0.05). In addition, the current efficiency of VFT to modulate sensorimotor cortical activities was higher than that of CFT pattern.The VFT pattern, especially dual 500µs wide pulse VFT, could enhance sensorimotor cortical excitability, and the central neural activities improvements may attribute to the fact that more afferent fibers are effectively activated. Therefore, our findings indicated the high potential of utilizing DFT with wide pulses to optimize NMES applications in motor rehabilitation.

Keywords: neuromuscular electrical stimulation, variable-frequency trains, cortical excitability, Afferent fibers, EEG

Received: 15 May 2025; Accepted: 15 Jul 2025.

Copyright: © 2025 Zhao, Yan, Zhang, Xie, Yang, Zou, Gao and Sun. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Yun Zhao, School of Smart Health, Chongqing Polytechnic University of Electronic Technology, Chongqing, China

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.