Evaluation of rats´ soleus muscle submitted to remobilization protocol with therapeutic ultrasound associated with static stretching

ABSTRACT

Despite the deleterious effects, immobilization, is still often used in the treatment of musculoskeletal disorders, even with the occurrence of muscular atrophy, its reversal is a major challenge to rehabilitation. The aim of this study was evaluate the tropism of rats soleus muscle submitted to remobilization with static stretching, preceded by ultrasound, thermal and non thermal. We used 28 rats divided into four groups G1‑immobilized and remobilized with static stretching, G2-remobilized with stretching preceded by ultrasound 1.0 W.cm–²; G3 – ultrasound at 0.5 W.cm–² , G4 – ultrasound with 0.2 W.cm–². All animals were immobilized in plantarflexion, producing shortening of the right soleus muscle for 15 days. For the groups subjected to remobilization with ultrasound doses were used according to the group, for 3 minutes, for 10 days with an interval of 2 days after the 5th treatment. After treatment with ultrasound (or not for the G1), the animals were subjected to 3 sets of 30 seconds, with 30 seconds interval between them, of static stretching of the soleus. The soleus were dissected, weighed and processed for preparation of histological slides in cross section, and evaluated the smallest diameter of 100 fibers per muscle. There was significant reduction in weight between left and right muscles in all groups, for diameters G3 showed no difference. Conclusion: stretching with or without ultrasound, was unable to reverse the deleterious effects of immobilization on muscle weight, but in the mean dose there was protective effect on the diameter of the fibers.