Muscle fibers have great plastic properties, responding to different stimuli with their weight increase or reduction, length and serial sarcomere number. The aim of this study was to analyze the static passive stretching in 3 daily bouts of 30 s and the free remobilization effects for two weeks, in the soleus muscle of rats immobilized in shortening position. For this purpose, 12 rats (Wistar) were used and divided in 2 groups: G1 (n=6) - left soleus muscle (LSM) immobilized and free in the cage (GIF); G2 (n=6) - LSM immobilized and stretched daily (GIS). The variations found between the LSM and RSM (right) of each group have been compared. The variables were: soleus muscle weight, length, serial sarcomeres number and sarcomere length. The results comparing LSM with RSM were: muscle weight: GIF=-23.16%, (p=0.0007), GIS-32.43% (p=0.0008); muscle length: GIF=-5.47% (p=0.0120); GIS=-9.99% (p=0.0034); serial sarcomere number: GIF=-15.42% (p=0.0047); GIS=-8.08% (p=0.0008); sarcomere length: GIF=11.16% (p=0.0142); GIS=-1.92% (p=0.3783). It can be concluded through these results that neither the stretching nor the free remobilization promotes restoration in the skeletal muscles structure submitted to prolonged immobilization.
immobilization; remobilization; muscle stretching
