持续的,对称的前臂曲任务对失败的扭矩和神经肌肉反应在3个肘部关节角度的影响
Dolores G Ortega1, Terry J Housh1, Robert W Smith1
1Department of Nutrition and Health Sciences, Exercise Physiology Laboratory, University of Nebraska-Lincoln, Lincoln, Nebraska; and.
Journal of strength and conditioning research
|December 12, 2023
概括
这项研究表明,持续的同度前臂运动减少了最大的自愿收缩,并改变了神经肌肉反应,影响因肘部关节角度而异. 这些变化表明,疲劳引起的代谢问题会影响特定的关节角度机制.
科学领域:
- 运动生理学 运动生理学
- 神经肌肉生理学 神经肌肉生理学
- 生物力学 生物力学
背景情况:
- 了解持续的等距离收缩如何影响最大自愿等距离收缩 (MVIC) 和神经肌肉反应对于优化训练和康复至关重要.
- 肘部关节角度 (JA) 可能会影响疲劳的发展和神经肌肉适应在等比前臂曲期间.
- 以前的研究已经探索了疲劳,但往往缺乏对多个关节角度的神经肌肉参数的详细分析.
研究的目的:
- 为了研究持续的等值前臂曲任务对任务失败对MVIC和神经肌肉反应 (电肌图和机械肌图) 在75°,100°和125°肘部关节角度的影响.
- 为了确定是否疲劳诱导的神经肌肉参数的变化是特定于肘部关节角度.
主要方法:
- 十一名女性在疲劳的同度收缩任务之前和之后,在三个肘部关节角度进行了前臂曲MVIC.
- 电肌图 (EMG) 的振幅 (AMP) 和平均功率频率 (MPF),以及机械图 (MMG) 的AMP和MPF从双腕中记录下来.
- 疲劳任务在100°肘部关节角度执行,直到任务失败,固定在8.8的感知劳动力评级上.
主要成果:
- 在所有关节角度上,MVIC和EMG MPF从预测到后测显著下降.
- 与100°和125°肘部关节角度相比,EMG MPF在75°显著更高.
- 在疲劳后,神经肌肉效率在100°和125°肘部关节角度下降,而EMG AMP在75°下降.
结论:
- 持续的同度前臂曲导致MVIC的减少和EMG MPF的改变,表明中心和/或外围疲劳.
- 观察到的MVIC下降和神经肌肉参数的变化表明,疲劳诱导的代谢干扰导致关节角度特定的神经肌肉反应.
- 神经肌肉参数,特别是EMG,可以提供有价值的见解,了解在同度收缩期间关节角度特定疲劳背后的机制.
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