The Effects of Stretching on Collagen Fibril Arrangements in the Endomysium of Rat Skeletal Muscle

Abstract

[Purpose] The purpose of this study was to clarify quantitative relations with the degree of an endomysium collagen fiber network change and the extension at the time of the rat soleus muscle extension. [Subjects] The subjects of this study were Wistar rats. [Method] Rats were divided into four experimental groups. The first group did not have the soleus muscle extended. In the second group, the soleus muscle was extended 10 mm. In the third group, the soleus muscle was extended 20 mm. In the fourth group, the soleus muscle was extended to the maximum. We examined the correlation between the extension distance and endomysium collagen fiber arrangement. [Result] The morphological changes of collagen fibers in the muscle membrane and the stretching muscle distance was significantly correlated. [Conclusion] It appears that collagen fibril arrangement in the endomysium move longitudinally toward the axis of the muscle fibers during muscle stretching.