Abstract
[Purpose] The purpose of this study was to verify the influence of the time duration of intermittent stretching on the inhibitory effects of disuse atrophy in the rat soleus muscle and to compare these effects across different sites along its longitudinal axis. [Subjects and Methods] Thirty 8-week-old male Wistar rats were divided into 4 experimental groups: control, hind-limb suspension (H), hind-limb suspension and stretching for 10 minutes every day (LST), and hind-limb suspension and stretching for 5 minutes every day (SST). At the end of the suspension period, the soleus muscle was excised and cut into proximal, middle, and distal samples, and the cross-sectional area (CSA) was measured. [Results] The cross-sectional area of muscle fibers was significantly higher in the LST and SST groups than in the H group in the middle and distal regions, and it was also higher in the SST group than in the LST group in the distal region. [Conclusion] These results suggest that the effect of intermittent stretching differs among the longitudinal sites of the rat soleus muscle, and depends on the duration of the stretching time.
