Yuichi Nishikawa1,2, Kohei Watanabe3, Tetsuya Takahashi4, Naohisa Hosomi4, Naoya Orita5, Yukio Mikami6, Hirofumi Maruyama4, Hiroaki Kimura6, Masayasu Matsumoto4. 1. Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan. yuichi@hiroshima-u.ac.jp. 2. Division of Rehabilitation, Department of Clinical Practice and Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan. yuichi@hiroshima-u.ac.jp. 3. Laboratory of Neuromuscular Biomechanics, School of International Liberal Studies, Chukyo University, 101-2 Yagotohonmachi, Showa-ku, Nagoya, 466-8666, Japan. 4. Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan. 5. Division of Rehabilitation, Department of Clinical Practice and Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan. 6. Department of Rehabilitation Medicine, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
Abstract
PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Entities:
Keywords:
Isometric contraction; Motor unit; Multi-channel surface electromyography; Vastus lateralis muscle; Young adult