Sex differences in variances of multi-channel surface electromyography distribution of the vastus lateralis muscle during isometric knee extension in young adults

• DOI: 10.1007/s00421-017-3559-3
• Publication Date: 2017-02-20T08:17:07Z
• Authors: Yuichi Nishikawa; Kohei Watanabe; Tetsuya Takahashi; Naohisa Hosomi; Naoya Orita; Yukio Mikami; Hirofumi Maruyama; Hiroaki Kimura; Masayasu Matsumoto
• Keywords: Vastus lateralis muscle; Motor unit; Coefficient of variation; Motor Unit Recruitment

The aim of the present study was to compare spatial electromyographic potential distribution during force production between healthy young female and male using multi-channel surface electromyography (multi-SEMG).Thirty healthy subjects (15 females) performed sustained isometric knee extension at 10% maximal voluntary contraction (MVC) task for 120 s. Multi-SEMG signals from the vastus lateralis muscle were detected and the modified entropy, coefficient of variation (CV), and correlation coefficient determined.The modified entropy and CV showed significant interaction and difference between females and males at all time points during the 10% MVC task. The correlation coefficient in females was significantly lower at 90 and 120 s than that of males.The multi-SEMG potential distribution pattern in females showed more varied motor unit recruitment during sustained low-intensity isometric contraction than that of males. Variations in motor unit recruitment may result from recruitment and/or de-recruitment of motor units.