Vandervoort A A, McComas A J
J Appl Physiol (1985). 1986 Jul;61(1):361-7. doi: 10.1152/jappl.1986.61.1.361.
The effects of aging on maximal voluntary strength and on the isometric twitch were determined in the ankle dorsiflexor and plantarflexor muscles of 111 healthy men and women aged 20-100 yr. Men were found to be stronger than women at all ages. In both sexes, the average values for maximum voluntary strength of the dorsiflexors and plantarflexors began to decline in the 6th decade. Although the absolute loss of strength was greater for the plantarflexor muscles, the relative losses were similar in the two muscle groups. During maximum voluntary effort, stimulation of motor nerves produced no additional torque in the majority of elderly men and women, indicating that these subjects remained able to utilize their descending motor pathways for optimal muscle activation. Comparisons of muscle compound action potentials, twitch torques, and muscle cross-sectional areas suggested that a decrease in excitable muscle mass was entirely responsible for the lower strength of the elderly. An additional effect of aging was the gradual prolongation of twitch contraction and half-relaxation times throughout the adult life-span.
在111名年龄在20至100岁的健康男性和女性的踝背屈肌和跖屈肌中，研究了衰老对最大随意肌力和等长收缩的影响。发现在所有年龄段男性都比女性更强壮。在两性中，背屈肌和跖屈肌最大随意肌力的平均值在60岁时开始下降。尽管跖屈肌的绝对力量损失更大，但两个肌肉群的相对损失相似。在最大随意用力期间，刺激运动神经在大多数老年男性和女性中并未产生额外的扭矩，这表明这些受试者仍能够利用其下行运动通路实现最佳肌肉激活。对肌肉复合动作电位、收缩扭矩和肌肉横截面积的比较表明，可兴奋肌肉质量的减少完全是老年人力量较低的原因。衰老的另一个影响是在整个成年期抽搐收缩和半松弛时间逐渐延长。
