Avis F J, Toussaint H M, Huijing P A, van Ingen Schenau G J
Eur J Appl Physiol Occup Physiol. 1986;55(5):562-8. doi: 10.1007/BF00421653.
Negative and positive work performed during leg extension movements of 53 well trained subjects was measured with the help of a special dynamometer. The subjects performed four maximal push off trials against five different loads (25-105 kg): two two-legged extensions from a squatting position (SM) with a knee angle of 70 degrees and two trials with a preliminary counter movement (CM) but with the same extension range as in the SM. Positive work differed only by about 4% between CM and SM in spite of large differences in initial forces at the onset of concentric contraction. Based on simulations, it is suggested that in CM the advantage of stored elastic energy can almost completely be nullified by the disadvantage of a limited shortening distance of the contractile elements. It is hypothesised that elastic energy in CM can only cause considerable extra work during concentric contraction compared to the maximal positive work done in SM if the total range of lengthening and shortening of the muscle(s) involved is larger in CM than in SM.
借助一种特殊的测力计，对53名训练有素的受试者在腿部伸展运动中所做的负功和正功进行了测量。受试者针对五种不同负荷（25 - 105千克）进行了四次最大蹬伸试验：两次从蹲姿开始的双腿伸展（SM），膝关节角度为70度，以及两次有预摆动作（CM）但伸展范围与SM相同的试验。尽管在向心收缩开始时初始力存在很大差异，但CM和SM之间的正功仅相差约4%。基于模拟结果表明，在CM中，储存弹性能量的优势几乎完全被收缩元件缩短距离受限的劣势所抵消。据推测，与SM中所做的最大正功相比，只有当CM中涉及的肌肉拉长和缩短的总范围大于SM时，CM中的弹性能量才会在向心收缩期间产生相当大的额外功。
