Related Experiment Video
Updated: May 4, 2026
Assessing Primary Motor Cortex Excitability and Excitability Modulation by Pairing Transcranial Magnetic Stimulation with Electromyography
Published on: October 7, 2025
Time-dependent changes in motor cortical excitability by electrical stimulation combined with voluntary drive
Kenichi Sugawara1, Tomofumi Yamaguchi, Shigeo Tanabe
1aDivision of Physical Therapy, Faculty of Health and Social Work, Kanagawa University of Human Services, Kanagawa bDepartment of Rehabilitation Medicine, Keio University School of Medicine, Tokyo cJapan Society for the Promotion of Science, Tokyo dSchool of Health Sciences, Faculty of Rehabilitation, Fujita Health University, Aichi eDepartment of Physical Therapy, Niigata University of Health and Welfare, Niigata fGraduate School of Health Science, Division of Physical Therapy and Occupational Therapy Science, Nagasaki University, Nagasaki, Japan.
Abstract:
Prolonged changes in primary motor cortex excitability in response to combined neuromuscular electrical stimulation (NMES) and voluntary contraction with motor evoked potentials (MEPs) were investigated by transcranial magnetic stimulation and recorded by mechanomyography. Participants included 22 healthy individuals. NMES was applied to the extensor carpi radialis (ECR) by voluntary ECR contraction with 20% maximum voluntary contraction (MVC) of wrist extension. MEPs were recorded from the flexor carpi radialis (FCR) and ECR at rest with NMES, at 20% MVC with NMES (combined), and at 20% MVC alone. Significant conditional effects were revealed in ECR and FCR. In the combined condition, MEPs showed gradual enhancement, and those in FCR were more inhibited than those in the control condition. Voluntary contraction with NMES increased primary motor cortex excitability in the agonist muscle, whereas the antagonist muscle might affect reciprocal modulation in the combined condition.
