在疲劳的收缩过程中,当扭矩但不是EMG匹配时,振荡驱动会增加,稳定性会受到损害
Justine R Magnuson1, Christina D Bruce1, Brian H Dalton1
1School of Health and Exercise Sciences and Centre for Heart, Lung and Vascular Health, The University of British Columbia, Kelowna, British Columbia, Canada.
Journal of neurophysiology
|November 6, 2024
概括
研究与EMG收缩匹配的肌肉疲劳表明,保持运动神经元池输出可以保持神经通信和性能. 相比之下,匹配扭矩收缩增加了脑肌肉交流,但影响了表现并增加了感知力的努力.
科学领域:
- 神经科学是一个神经科学.
- 运动生理学 运动生理学
- 发动机控制器的控制器
背景情况:
- 调查肌肉疲劳是具有挑战性的,因为难以将神经刺激性变化与下降驱动隔离出来.
- 匹配表面电肌图 (EMG) 越来越多地用于在疲劳研究期间保持运动神经元池输出.
- 匹配的EMG收缩对持续任务中的皮质贡献和肌肉间通信的影响仍然不清楚.
研究的目的:
- 使用匹配扭矩与匹配EMG协议,在持续的同度收缩期间比较神经和性能变化.
- 在不同的疲劳诱导条件下,研究皮质肌肉连贯性 (CMC) 和肌肉间连贯性 (IMC) 的变化.
- 为了确定保持运动神经元池输出是否会影响神经战略,在疲劳期间保持肌肉功能.
主要方法:
- 16名参与者在20%的最大自愿收缩 (MVC) 扭矩下进行了10分钟的对称肘部曲收缩,或者匹配了双臂臂EMG.
- 电脑电图 (EEG) 和表面EMG从感觉运动皮质,双肩肌和三脚肌肌肉中记录.
- 测量包括MVC扭矩,自动激活,扭矩稳定性,CMC,IMC和感知力度的额定值.
主要成果:
- 匹配扭矩收缩增加了CMC (~75%) 和IMC (~97%),但降低了MVC扭矩 (~33%),自愿激活 (~9%) 和扭矩稳定 (~83%).
- 匹配的EMG收缩减少了MVC扭矩 (~21%) 没有改变CMC,IMC或EMG稳定性.
- 在匹配扭矩条件下,与匹配EMG相比,感知力在6分钟内更高.
结论:
- 匹配扭矩收缩诱导更大的神经同步 (CMC,IMC),但导致性能降低和更高的感知力度.
- 匹配的EMG收缩,通过保持运动神经元池输出,利用不同的神经战略来保持肌肉输出和任务性能.
- 这些发现突出了不同的神经适应疲劳,这取决于用于维持肌肉活动的实验协议.
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