独特的神经机制是低力弹道收缩速度控制的基础
Joongsuk J Kim1, Stefan Delmas1, Yoon Jin Choi1
1Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
Journal of human kinetics
|February 21, 2024
概括
速度控制假设不适用于低力收缩. 达到峰值力的时间 (TPF) 随力幅度而变化,这表明在低而不是高的肌肉力水平上使用不同的神经控制策略.
科学领域:
- 人体生理学 人体生理学
- 神经肌肉控制控制神经肌肉控制
- 生物力学 生物力学
背景情况:
- 速度控制假设认为,力发展速度 (RFD) 是由力振幅限制的,这是由于不断的时间到峰值力 (TPF).
- 这种假设尚未在广泛的亚最大力输出范围内得到严格测试,特别是低于20%的最大自愿收缩 (MVC).
研究的目的:
- 调查RFD和力幅度在广泛的亚最大收缩 (2-85% MVC) 的频谱之间的关系.
- 探索影响TPF调节的基础肌肉活动模式 (EMG) 在不同的力量水平.
主要方法:
- 18名年轻成年人在7个强力级别 (2-85% MVC) 进行了弹道指指绑架.
- 每个试验的量化TPF,RFD和电肌图 (EMG) 爆发特征.
- 在不同的力输出中分析了TPF和EMG参数之间的关联.
主要成果:
- 在测试的力范围 (2-85% MVC) 中,TPF并非恒定,而是显著变化.
- 与较高的力 (30-85% MVC) 相比,RFD斜率在较低的力 (2-15% MVC) 时更.
- TPF调节在低力和高力之间有所不同,与EMG爆发持续时间的变化和整体有关.
结论:
- 速度控制假设是有限的,无法解释所有次最大水平的力调节.
- 神经元的可变性在30%以下的力量控制中显得至关重要,而神经元的振幅在30%以上的MVC中占主导地位.
- 需要修订理论框架,以解释不同强度的力量发育的独特神经机制.
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