De Jaeger Dominique, Joumaa Venus, Herzog Walter
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; and Laboratoire de Physiologie et de Biomécanique de la Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; and.
J Appl Physiol (1985). 2015 Jun 15;118(12):1467-73. doi: 10.1152/japplphysiol.00515.2014. Epub 2015 Apr 2.
In humans, enhanced joint range of motion is observed after static stretch training and results either from an increased stretch tolerance or from a change in the biomechanical properties of the muscle-tendon unit. We investigated the effects of an intermittent stretch training on muscle biomechanical and structural variables. The left plantarflexors muscles of seven anesthetized New Zealand (NZ) White rabbits were passively and statically stretched three times a week for 4 wk, while the corresponding right muscles were used as nonstretched contralateral controls. Before and after the stretching protocol, passive torque produced by the left plantarflexor muscles as a function of the ankle angle was measured. The left and right plantarflexor muscles were harvested from dead rabbits and used to quantify possible changes in muscle structure. Significant mass and serial sarcomere number increases were observed in the stretched soleus but not in the plantaris or medial gastrocnemius. This difference in adaptation between the plantarflexors is thought to be the result of their different fiber type composition and pennation angles. Neither titin isoform nor collagen amount was modified in the stretched compared with the control soleus muscle. Passive torque developed during ankle dorsiflexion was not modified after the stretch training on average, but was decreased in five of the seven experimental rabbits. Thus, an intermittent stretching program similar to those used in humans can produce a change in the muscle structure of NZ White rabbits, which was associated in some rabbits with a change in the biomechanical properties of the muscle-tendon unit.
在人类中，静态拉伸训练后可观察到关节活动范围增加，这要么是由于拉伸耐受性提高，要么是由于肌肉 - 肌腱单元生物力学特性的改变。我们研究了间歇性拉伸训练对肌肉生物力学和结构变量的影响。七只麻醉的新西兰白兔的左侧跖屈肌每周被动静态拉伸三次，持续4周，而相应的右侧肌肉用作未拉伸的对侧对照。在拉伸方案前后，测量左侧跖屈肌作为踝关节角度函数产生的被动扭矩。从处死的兔子身上采集左右跖屈肌，用于量化肌肉结构的可能变化。在拉伸的比目鱼肌中观察到显著的质量和串联肌节数量增加，但在跖肌或内侧腓肠肌中未观察到。跖屈肌之间这种适应性差异被认为是它们不同的纤维类型组成和羽状角的结果。与对照比目鱼肌相比，拉伸后肌联蛋白异构体和胶原蛋白含量均未改变。平均而言，拉伸训练后踝关节背屈时产生的被动扭矩没有改变，但在七只实验兔中有五只降低了。因此，类似于人类使用的间歇性拉伸方案可以使新西兰白兔的肌肉结构发生变化，在一些兔子中这与肌肉 - 肌腱单元生物力学特性的变化有关。
