刺激频率对人体四头肌同位素收缩功能的同位素和同位素收缩功能的不同影响
Alexander M Zero1, Michael T Paris1,2, Charles L Rice1,3
1Faculty of Health Sciences, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada.
Journal of applied physiology (Bethesda, Md. : 1985)
|June 6, 2024
概括
电刺激的肌肉收缩表明,同度扭矩不是动态收缩功能的可靠替代品. 机械输出功率需要比同度扭矩更高的刺激频率,突出显示了肌肉评估的差异.
科学领域:
- 人类肌肉生理学 人类肌肉生理学
- 评估神经肌肉功能的评估.
- 运动科学运动科学
背景情况:
- 电气引起的收缩对于特征肌肉功能至关重要,通过检查刺激频率和收缩输出之间的关系.
- 之前的研究主要利用同度收缩,限制了对动态肌肉反应的理解.
- 对等度和等度收缩之间的区别对于准确解释肌肉性能至关重要.
研究的目的:
- 为了比较电刺激的频率和收缩功能关系之间的同位数和同位素收缩.
- 为了研究在动态膝盖延伸器收缩过程中不同负荷如何影响这些关系.
- 为了确定同度扭矩是否可以作为动态收缩功能的替代措施.
主要方法:
- 16名休活动参与者 (5名女性) 接受了14个频率 (1-100赫兹) 的膝盖伸缩器电刺激.
- 在四个条件下进行了收缩:以0%,7.5%和15%的最大自发收缩 (MVC) 负荷为同位数和同位数.
- 包括扭矩,角速度和机械功率在内的收缩参数被测量并作为100 Hz刺激的百分比进行比较.
主要成果:
- 机械功率与频率的关系与等比扭矩,同心扭矩和速度与频率的关系相比,无论负载如何,都始终向右移动.
- 增加的同位荷载 (0-15% MVC) 导致同心扭矩-频率关系向左移,速度-频率关系向右移.
- 扭矩和速度频率关系之间的相对转移因负载而异,表明动态肌肉功能的负载依赖变化.
结论:
- 同度扭矩不是评估动态同位素收缩功能的合适替代品,原因是频率依赖的响应不同.
- 电气唤起的收缩功能的解释受到收缩的类型 (同位数与动态),施加的负载和刺激频率的显著影响.
- 这些发现强调了在解释肌肉功能评估时考虑特定任务要求的重要性.
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