Department of Life Science, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
Eur J Appl Physiol. 2010 Oct;110(3):507-14. doi: 10.1007/s00421-010-1528-1. Epub 2010 Jun 10.
The purpose of this study was to investigate the mechanical properties of muscle and tendon in long distance runners and their relations to running performance. Fifteen long distance runners (LDR) and 21 untrained subjects (CON) participated in this study. Muscle strength and activation level of knee extensors and plantar flexors were measured. Tendon elongation was determined using ultrasonography, while subjects performed ramp isometric knee extension and plantar flexion up to the voluntary maximum. Relative MVC (to body mass) of LDR was significantly lower than that of CON for knee extensors, but not for plantar flexors. No significant difference in the neural activation levels was found between LDR and CON for both sites. Maximal tendon elongation of LDR was significantly lower than that of CON for knee extensors, but not for plantar flexors. Furthermore, faster running time in a 5,000 m race (best official record of LDR) was associated with lower tendon stiffness for both sites. In conclusion, the tendon of long distance runners is less extensible than those of untrained subjects for knee extensors, but not for plantar flexors. For both sites, however, the lower tendon stiffness may be in favor of the running performance in long distance runners.
本研究旨在探讨长跑运动员肌肉和肌腱的力学特性及其与跑步表现的关系。本研究纳入了 15 名长跑运动员（LDR）和 21 名未经训练的受试者（CON）。测量了膝关节伸肌和跖屈肌的肌肉力量和激活水平。使用超声检查确定肌腱伸长，同时受试者在斜坡等长膝关节伸展和跖屈至最大自愿收缩。与 CON 相比，LDR 的膝关节伸肌的相对 MVC（相对于体重）明显较低，但跖屈肌则不然。在两个部位，LDR 和 CON 之间的神经激活水平没有显著差异。与 CON 相比，LDR 的膝关节伸肌的最大肌腱伸长明显较低，但跖屈肌则不然。此外，在 5000 米比赛中（LDR 的最佳官方记录），更快的跑步时间与两个部位的肌腱刚度降低有关。总之，与未经训练的受试者相比，长跑运动员的膝关节伸肌的肌腱伸展性较低，但跖屈肌则不然。然而，对于两个部位，较低的肌腱刚度可能有利于长跑运动员的跑步表现。
