Abstract

Objective: The diagnostic of muscular lesions suffered by athletes is done through a clinical diagnosis accompanied by confirmation tests using imaging techniques on the lesion (ultrasonography and/or magnetic resonance) as well as laboratory techniques for blood analysis that detect usually the presence of non-specific muscle markers . The aim of the study is the evaluation of fast and slow-twitch fibres injury using specific muscle markers for those fibres. Design: Blood samples were obtained from 51 non-sport people and 36 sportsmen with skeletal muscle injury. Western blood was performed to determine fast and slow myosin and creatin kinase. Skeletal muscle damage was diagnosed according to physical examination, ultrasonography and magnetic resonance and biochemical markers criterion. Results: The imaging tests have been shown to be excellent for the detection and confirmation of Grade II and III lesions. However, Grade I lesions often remain unconfirmed by these techniques. Grade I lesions show higher fast myosin than slow myosin with very low CK increase. Grade II and III show high values of both myosin. Conclusions: The evaluation of fast and slow myosin in the blood 48 hours after the lesion occurs has been seen to be a good parameter for the detection of Type I lesions specially, based on the fact that fast myosin is an exclusive skeletal muscle marker. The correct diagnosis of Grade I lesions can promote prevention of the injury’s progression in athletes undergoing continual training sessions and competitions, thus aiding sports physicians in their decisions.