van Schaik C S, Hicks A L, McCartney N
Department of Kinesiology, McMaster University, Hamilton, Ontario.
J Gerontol. 1994 May;49(3):B121-7. doi: 10.1093/geronj/49.3.b121.
Aging is thought to be associated with a decreased elasticity of skeletal muscle, which may be predicted to affect the optimal length at which peak tension is developed. This was assessed in the present study, in which we examined the effect of aging on the muscle length-tension relationship in the right ankle dorsiflexors of 60 subjects aged 20-40 years (M = 25.3; 15 males, 15 females) and 60-80 years (M = 68.8; 15 males, 15 females). Evoked contractile properties, 1-sec tetanic contractions (at 20, 50, and 80 Hz), and maximal voluntary contractions (MVC) were measured at 10 joint angles (15 degrees dorsiflexion to 30 degrees plantarflexion, in 5 degrees increments). Peak twitch torque occurred at the extreme of plantarflexion (30 degrees P) in both elderly and young adults, and although males had significantly greater twitch torques than females, there was no difference between the elderly and young adults. Maximum tetanic torque and MVC torque occurred at 30 degrees P and 20 degrees P, respectively, but in this case the young adults were significantly stronger than the elderly adults, and the males stronger than the females at all joint angles. There was no difference in the torque-angle relationship between elderly and young adults in any of the evoked or voluntary measures. At each of the three frequencies, the rise time of tetanic torque was also similar between elderly and young adults. These results suggest that any age-related change in the elastic properties of the ankle dorsiflexors does not affect the length (as inferred by joint angle)-tension relationship in this muscle group.
衰老被认为与骨骼肌弹性下降有关，这可能会影响产生峰值张力的最佳长度。本研究对此进行了评估，我们研究了衰老对60名年龄在20 - 40岁（平均年龄25.3岁；15名男性，15名女性）和60 - 80岁（平均年龄68.8岁；15名男性，15名女性）受试者右踝背屈肌肌肉长度 - 张力关系的影响。在10个关节角度（从背屈15度到跖屈30度，以5度递增）测量诱发收缩特性、1秒强直收缩（频率为20、50和80赫兹）以及最大自主收缩（MVC）。在老年人和年轻人中，峰值抽搐扭矩均出现在跖屈极限（30度P），尽管男性的抽搐扭矩明显大于女性，但老年人和年轻人之间没有差异。最大强直扭矩和MVC扭矩分别出现在30度P和20度P，但在这种情况下，年轻人明显比老年人更强壮，并且在所有关节角度男性都比女性更强壮。在任何诱发或自主测量中，老年人和年轻人之间的扭矩 - 角度关系没有差异。在三个频率中的每一个频率下，老年人和年轻人之间强直扭矩的上升时间也相似。这些结果表明，踝背屈肌弹性特性的任何与年龄相关的变化都不会影响该肌肉群的长度（由关节角度推断） - 张力关系。
