Age differences in dynamic fatigability and variability of arm and leg muscles: Associations with physical function.
Age differences in dynamic fatigability and variability of arm and leg muscles: Associations with physical function.
复制标题
DOI：
10.1016/j.exger.2016.10.008
复制
发表时间：
2017-01
影响因子：
3.9
通讯作者：
Hunter SK
中科院分区：
文献类型：
--
作者：
Senefeld J;Yoon T;Hunter SK
目前尚不清楚下肢肌肉快速动态收缩的疲劳性是否也发生在上肢肌肉中。我们比较了年龄相关的疲劳性和最大努力重复动态收缩的膝伸肌和肘屈肌的变异性;并确定疲劳性之间的关联，收缩和功能性能之间的速度变异性。35名青年（16名男性; 21.0±2.6岁）和32名老年（18名男性; 71.3±6.2岁）成年人在不同的日子进行了一项动态疲劳任务，包括90次最大努力、快速、同心、等张收缩（1次收缩/3 s），负荷相当于手肘屈肌和膝伸肌最大随意等长收缩（MVIC）扭矩的20%。老年人也进行了平衡和步行耐力的测试。与年轻人相比，老年人手肘屈肌和膝伸肌的疲劳相关峰值速度降低更大（P<0.05），无性别差异（P>0.05）。老年人有更大的变异性峰值速度在膝伸肌，但不是手肘屈肌疲劳任务。膝伸肌疲劳性的年龄差异（35.9%）大于肘屈肌疲劳性的年龄差异（9.7%），P<0.05。在老年人中，膝伸肌的疲劳性较低与步行耐力（r=-0.34，P=0.048）和平衡（r=-0.41，P=0.014）较高相关。与年龄相关的增加疲劳性的动态疲劳任务是更大的膝伸肌相比，手肘屈肌肌肉的男性和女性，更大的疲劳性与较少的步行耐力和平衡。
It is not known whether the age-related increase in fatigability of fast dynamic contractions in lower limb muscles also occurs in upper limb muscles. We compared age-related fatigability and variability of maximal-effort repeated dynamic contractions in the knee extensor and elbow flexor muscles; and determined associations between fatigability, variability of velocity between contractions and functional performance. 35 young (16 males; 21.0±2.6 years) and 32 old (18 males; 71.3±6.2 years) adults performed a dynamic fatiguing task involving 90 maximal-effort, fast, concentric, isotonic contractions (1 contraction/3 s) with a load equivalent to 20% maximal voluntary isometric contraction (MVIC) torque with the elbow flexor and knee extensor muscles on separate days. Old adults also performed tests of balance and walking endurance. Old adults had greater fatigue-related reductions in peak velocity compared with young adults for both the elbow flexor and knee extensor muscles (P<0.05) with no sex differences (P>0.05). Old adults had greater variability of peak velocity during the knee extensor, but not during the elbow flexor fatiguing task. The age difference in fatigability was greater for the knee extensor muscles (35.9%) compared with elbow flexor muscles (9.7%, P<0.05). Less fatigability of the knee extensor muscles was associated with greater walking endurance (r=−0.34, P=0.048) and balance (r=−0.41, P=0.014) among old adults. An age-related increase in fatigability of a dynamic fatiguing task was greater for the knee extensor compared with the elbow flexor muscles in males and females, and greater fatigability was associated with lesser walking endurance and balance.