Aura O, Komi P V
Int J Sports Med. 1986 Jun;7(3):137-43. doi: 10.1055/s-2008-1025751.
Mechanical efficiency of positive work (eta+) and elastic behavior of human skeletal muscles were investigated on a special sledge apparatus which allowed the use of the normal stretch-shortening cycle exercises. Twenty-five young men were investigated in a total of 92 exercise situations, in which the intensity of the prestretch (eccentric contraction) was different, but the shortening phase (concentric contraction) was kept constant in all conditions. The results demonstrated that eta+ was on the average 35.8% +/- 6.4% and correlated positively with the prestretch intensity (r = 0.413; P less than 0.001), reaching a highest individual value of 51.5%. Estimation performed on the elastic characteristics of the leg extensor muscles confirmed an earlier suggestion that the pure muscle elasticity plays an important role in potentiating performance in stretch-shortening cycle exercises. The analysis of the myoelectrical activity of the leg extensor muscles showed that the nervous system plays an essential role in regulating muscle stiffness and thus utilization of muscle elasticity in ballistic exercises.
利用一种特殊的雪橇装置对正向功的机械效率（η+）和人体骨骼肌的弹性行为进行了研究，该装置允许进行正常的拉长-缩短周期运动。对25名年轻男性进行了总共92种运动情况的研究，其中预拉伸（离心收缩）强度不同，但在所有条件下缩短阶段（向心收缩）保持恒定。结果表明，η+平均为35.8%±6.4%，与预拉伸强度呈正相关（r = 0.413；P<0.001），个体最高值达到51.5%。对腿部伸肌弹性特征的评估证实了先前的一项推测，即纯肌肉弹性在增强拉长-缩短周期运动的表现中起重要作用。对腿部伸肌肌电活动的分析表明，神经系统在调节肌肉僵硬度以及因此在弹道运动中利用肌肉弹性方面起着至关重要的作用。
