Chronological changes in neuromuscular cooperativeness before and after muscle fatigue loading using the silent period of the quadriceps and hamstrings in young female athletes

• Published in: Journal of Physical Therapy Science Vol. 33; no. 12; pp. 908 - 911
• Main Authors: Ito-Oonishi, Sakiko, Takemura, Masahiro, Kanamori, Akihiro, Kusumoto, Yasuaki, Miyakawa, Shumpei
• Format: Journal Article
• Language: English
• Published: Tokyo The Society of Physical Therapy Science 01.01.2021; Japan Science and Technology Agency
• Subjects: Muscle fatigue; Neuromuscular cooperativeness; Original; Sports injuries; Switching silent period
• ISSN: 0915-5287; 2187-5626
• DOI: 10.1589/jpts.33.908

[Purpose] Understanding the neuromuscular cooperativeness functions when an athlete is fatigued is essential in preventing sports injuries and examining post-injury return standards. This study aimed to investigate the kinds of changes in neuromuscular cooperativeness before and after fatigue loading. [Participants and Methods] Fifteen female university athletes were examined for chronological changes in neuromuscular cooperativeness. Muscle fatigue loading was performed using BIODEX (180°/s) during knee flexion and extension exercises on one side. Surface electromyography of the rectus femoris and biceps femoris was performed on both sides before and immediately, 5 min, 10 min, and 15 min after loading. The switching silent period and pre-motor time were calculated from the electromyographic waveforms to indicate neuromuscular cooperativeness. [Results] The switching silent periods in the loading side immediately and 5 min after loading were significantly prolonged compared with that before loading. [Conclusion] Muscle fatigue loading instantaneously prolonged the switching silent period and decreased the neuromuscular cooperativeness. Furthermore, recovery generally occurred within 10 minutes after loading.