Gajdosik R L, Vander Linden D W, Williams A K
Physical Therapy Department, University of Montana, Missoula 59812, USA.
Eur J Appl Physiol Occup Physiol. 1996;74(3):279-86. doi: 10.1007/BF00377451.
The purpose of this study was to investigate the influence of age on concentric isokinetic torque (CIT) and passive extensibility (PE) variables of the calf muscles of healthy women. Ten younger women [31.9 (SD 6.1) years] and ten older women [71.1 (SD 6.6) years] were tested using a KIN-COM 500H dynamometer. The PE was tested by stretching the muscles from relaxed plantarflexion to the maximal dorsiflexion (DF) angle at 5 degrees.s-1 without raw electromyogram (EMG) activity exceeding 0.05 mV. The maximal CIT was tested from the maximal DF angle 60 degrees into plantarflexion at four randomly ordered velocities of 30,60, 120, and 180 degrees.s-1. Separate analysis of variance (ANOVA) tests showed that the standardized (% body mass) concentric peak and mean torques were lower for the older women for all isokinetic velocities (p < 0.001). The "angular delay" from the onset of concentric activation to peak torque was smaller for the older women at 120 and 180 degrees.s-1 (p < 0.05). Age showed negative relationships (Pearson r) with all standardized peak torques (p < or = 0.001) and mean torques (p < 0.001), and the "angular delay" at 120 and 180 degrees.s-1 (p < or = 0.05). Independent t-tests showed that the maximal DF angle and the change in the PE angle from an initial angle (defined at 10% of the maximal passive torque) to the maximal DF angle were less for the older women (p < 0.05). Age was negatively related to the maximal DF angle and the change in the PE angle (p < 0.01). The results suggest an age-related decrease in calf muscle CIT, muscle length and PE. The smaller "angular delay" for the older women at 120 and 180 degrees.s-1 indicates that CIT testing at rapid velocities can be used to examine age-related changes in calf muscle contractile properties in relation to rapid velocities of movement.
本研究的目的是调查年龄对健康女性小腿肌肉的等速向心扭矩（CIT）和被动伸展性（PE）变量的影响。使用KIN-COM 500H测力计对10名年轻女性[31.9（标准差6.1）岁]和10名年长女性[71.1（标准差6.6）岁]进行测试。通过在5度·秒⁻¹的速度下将肌肉从放松的跖屈拉伸到最大背屈（DF）角度来测试PE，且原始肌电图（EMG）活动不超过0.05 mV。从最大DF角度60度开始，以30、60、120和180度·秒⁻¹这四个随机排序的速度向跖屈方向测试最大CIT。独立方差分析（ANOVA）测试表明，在所有等速速度下，年长女性的标准化（%体重）向心峰值扭矩和平均扭矩均较低（p < 0.001）。在120和180度·秒⁻¹时，年长女性从向心激活开始到峰值扭矩的“角度延迟”较小（p < 0.05）。年龄与所有标准化峰值扭矩（p ≤ 0.001）和平均扭矩（p < 0.001）以及120和180度·秒⁻¹时的“角度延迟”呈负相关（Pearson相关系数r）。独立t检验表明，年长女性的最大DF角度以及从初始角度（定义为最大被动扭矩的10%）到最大DF角度的PE角度变化较小（p < 0.05）。年龄与最大DF角度和PE角度变化呈负相关（p < 0.01）。结果表明，小腿肌肉的CIT、肌肉长度和PE存在与年龄相关的下降。年长女性在120和180度·秒⁻¹时较小的“角度延迟”表明，快速速度下的CIT测试可用于检查与快速运动速度相关的小腿肌肉收缩特性的年龄相关变化。
