The focus of this research was to investigate the efects of acute blunt trauma, on the ultrastructural and protein content of skeletal muscles. A simple device for producing a humane and reproducible experimental model of blunt trauma to rat muscle was used. Ultrastructural events in the traumatized muscle were observed over 14 days. From 0 to 2 days after trauma there was a marked loss of muscle protein content, associated with an acute inflammatory response. From day 3 to 14 days, the muscle underwent regeneration with a rapid proliferation of sarcolemmal nuclei, activation of satellite cells, and the restoration of sarcomeres. By three days post trauma, muscle protein content decreased (35-47%) compared to muscle of control rats (p>0.05).