急性normobaric缺氧导致扭矩-频率关系向右转移,但对后激活电位化没有影响
Christina D Bruce1, Mathew I B Debenham1,2, Brian H Dalton1
1Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada.
Journal of applied physiology (Bethesda, Md. : 1985)
|September 19, 2024
概括
低氧水平 (低氧) 会损害膝盖延伸器的强度,但不会影响后激活潜能 (PAP). 然而,缺氧会改变扭矩-频率关系,需要更高的频率才能达到最大扭矩.
科学领域:
- 运动生理学 运动生理学
- 骨肌肉生理学 骨肌肉生理学
- 缺氧研究 缺氧研究
背景情况:
- 低比例的吸入氧气 (低氧) 影响人类骨肌肉功能.
- 低氧对后活化强化 (PAP) 和扭矩-频率 (T-F) 关系的影响尚未完全理解.
研究的目的:
- 为了研究2小时和4小时的诺莫巴里克缺氧对膝盖延伸器中的PAP的影响.
- 为了检查2小时的normobaric缺氧对dorsiflexors的T-F关系的影响.
主要方法:
- 参与者接受了常态低氧暴露 (FiO2 = 0.11).
- 在最大自愿收缩 (MVC) 之前和之后,通过大腿神经刺激来评估PAP.
- 通过在不同频率上刺激常神经来确定T-F关系.
主要成果:
- 缺氧降低了膝盖伸缩器中的MVC力和自愿激活,但没有改变PAP大小.
- 随着时间的推移,PAP的大小在对照日期间增加.
- Dorsiflexor MVC扭矩和自愿激活不受低氧的影响.
- 缺氧导致T-F关系向右转移,需要更高的频率来达到50%的最大扭矩.
结论:
- 两小时的正常性缺氧会损害神经驱动到膝盖延伸器的神经驱动,而不会影响PAP机制.
- 缺氧会改变背肌的收缩性质,从而改变T-F关系.
- 这些发现提高了对急性缺氧对骨肌肉功能的影响的理解.
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