Effects of therapeutic ultrasound on the regeneration of skeletal myofibers after experimental muscle

Therapeutic ultrasound is used by many in the treatment of muscle injuries, but no previous attempts to objectively assess its effects on regenerating skeletal myofibers have been published. In this descriptive study, we foll owed the regeneration of contusion injury to the rat gastrocnemius muscle d uring treatment with pulsed ultrasound, The speed of myoregeneration in ult rasound-treated animals was compared with that in control animals by immuno histochemical, morphometric, and scintigraphic analyses. Although satellite cell proliferation was enhanced significantly (up to 96%) by the ultrasoun d treatment during the early stages of regeneration, there was no such effe ct on myotube production. The period of rapid fibroblast proliferation was extended from 3 to 4 days in the control group to 7 to 10 days in the ultra sound therapy groups, whereas recapillarization was virtually unaffected. W e conclude that although treatment with pulsed ultrasound can promote the s atellite cell proliferation phase of the myoregeneration, it does not seem to have significant effects on the overall morphological manifestations of muscle regeneration.