"肌肉智慧"重新审视:刺激速度下降可以减轻扭矩损失
Raaj A Dudani1, Alexander M Zero1, Charles L Rice1,2
1School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada.
Experimental physiology
|January 31, 2025
概括
在高强度收缩过程中,降低动力单元发射率 (MUFRs) 通过匹配肌肉减速来保持扭矩,支持肌肉减速.
科学领域:
- * * 人体生理学 人体生理学
- * 神经肌肉功能
- * 运动科学 运动科学
背景情况:
- * 在最大自发收缩 (MVCs) 期间,发动机单元发射率 (MUFRs) 降低,伴随着扭矩损失.
- * 假设这种下降是一种保护机制 ("肌肉智慧"),可以保护肌肉功能.
- * 然而,减少的MUFR是否有助于扭矩损失仍有争议.
研究的目的:
- * 调查MUFR下降在疲劳收缩期间扭矩维持中的作用.
- * 为了比较在恒定下扭矩损失与衰减的电刺激率,模仿MVC MUFRs.
主要方法:
- * 八名男性和五名女性 (21-30岁) 接受了三次60秒的筋疲力尽状态.
- *条件包括持续的MVC,持续的40Hz电刺激和指数式衰减刺激 (40Hz至20Hz).
- *评估了扭矩损失和电生理反应 (M波,抽).
主要成果:
- * 与恒定刺激和MVC相比,衰减的刺激速率导致扭矩损失显著减少.
- *刺激频率的突然降低 (40 Hz 到 20 Hz) 增加了扭矩,而增加 (20 Hz 到 40 Hz) 加快了扭矩损失.
- *引起的抽在所有条件下都减慢了速度,但只有在持续的高频刺激下,M波幅度的减少才发生.
结论:
- * 降低刺激率,模仿MUFR下降,通过优化激活与疲劳诱导的收缩减速来保持扭矩.
- * 这支持"肌肉智慧"假设,表明减少激活率可以防止扭矩损失.
- * 保存的外围电导率也有助于在疲劳收缩期间保持扭矩.
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