Age-related muscle fatigue after a low-force fatiguing contraction is explained by central fatigue.
Age-related muscle fatigue after a low-force fatiguing contraction is explained by central fatigue.
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低力疲劳收缩后与年龄相关的肌肉疲劳可以用中枢疲劳来解释。
DOI：
10.1002/mus.20969
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发表时间：
2008
期刊：
影响因子：
3.4
通讯作者：
Hunter,SandraK
中科院分区：
文献类型：
--
作者：
Yoon,Tejin;De-Lap,BonnieSchlinder;Griffith,ErinE;Hunter,SandraK
在低力和高力等长收缩期间和之后，中枢疲劳的贡献随着年龄的增长而持续直到失败。我们比较了失败的时间和自愿激活的变化测量使用运动点刺激的15名年轻人和15名老年人的等长收缩持续与手肘屈肌在20%和80%的最大随意收缩（MVC）的力量。年轻人有一个短暂的时间任务失败比老年人的20%MVC疲劳收缩，但类似的持续时间为80%的任务。自愿激活减少在20%MVC任务结束时，但老年人比年轻人的幅度更大。低力任务后MVC扭矩的减少与自主激活的减少相关。在完成80%的任务后，年轻人和老年人的自愿激活下降到相似的水平。肱二头肌和肱桡肌在疲劳收缩过程中的肌电图活动水平（% MVC）大于年轻人的20%MVC任务，但与年龄相似的80%MVC任务。我们的研究结果表明，在年轻人和老年人中，收缩的强度和持续时间可以被操纵，以诱导中枢神经系统内不同程度的疲劳。老化加剧：（1）低力疲劳性收缩后中枢神经系统内立即出现疲劳，以及（2）老年人神经肌肉康复期间可能出现大的神经适应。肌肉神经，2008年
The contribution of central fatigue during and after low‐ and high‐force isometric contractions sustained until failure with age is not established. We compared the time to failure and changes in voluntary activation measured using motor point stimulation of 15 young and 15 old adults for an isometric contraction sustained with the elbow flexor muscles at 20% and 80% of maximal voluntary contraction (MVC) force. Young adults had a briefer time to task failure than old adults for the 20% MVC fatiguing contraction, but a similar duration for the 80% task. Voluntary activation was reduced at the end of the 20% MVC task, but by greater magnitudes for old than young adults. The reduction in MVC torque after the low‐force task was associated with the reduction in voluntary activation. After the 80% task, voluntary activation declined to similar levels for the young and old adults. Electromyographic activity levels (% MVC) of the biceps brachii and brachioradialis muscles during the fatiguing contraction were greater for the old than young for the 20% MVC task, but similar with age for the 80% MVC task. Our findings indicate that intensity and duration of contraction can be manipulated in young and old adults to induce varying magnitudes of fatigue within the central nervous system. Aging increases: (1) fatigue within the central nervous system immediately after a low‐force fatiguing contraction, and (2) the potential for large neural adaptations during neuromuscular rehabilitation in old adults. Muscle Nerve, 2008