Effects of Rat Hind Limb Unweighting on the Extensibility of the Soleus and Skin around a Joint Contracture

Abstract

[Purpose] The purpose of this study was to clarify the effects of unweighting the lower limbs on the extensibilities of the skin and soleus muscle around a contracted joint. [Subjects and Methods] Twelve wistar rats were divided into two experimental groups. The right ankle joints of the first experimental group were fixed in full plantar flexion (F). The hind limbs of the second experimental group were suspended, and their right ankle joints were fixed in full plantar flexion (FS). The period of fixation was one week. On the last day, the extensibilities of the soleus muscles and skin of the right ankle joint were measured. [Results] The extensibility of the soleus muscle of the FS group decreased more than that of the F group. [Conclusion] Our results indicate that unweighting the hind limbs of rats may cause severe joint contractures by decreasing muscle extensibility.