Muscle contusions or extrinsic muscle lesions are frequently encountered in sports medicine; indeed they represent the second most common cause of morbidity in athletes. Participation in contact sports is a major risk factor. Because of the high frequency and the severity of muscle contusions, some of the governing bodies in some sports, like American football and ice hockey, have implemented prevention strategies and changed their regulations by authorizing helmets and protective padding. However, there is no validated scientific evidence to prove that these measures provide any meaningful benefit. The site of the muscle contusion depends on the type of sport, with the lower limb being the most commonly cited location in the literature. Despite its high incidence, there is no evidence from studies human on the optimal treatment. In the literature, contusions of the quadriceps muscle are the most well studied. On the other hand, numerous animal studies have shed light on the pathogenesis and the healing process of muscle lesions. The healing process must be clearly understood to provide the most efficient treatment plan. Moreover a thorough clinical examination associated with imaging is required. A detailed grading system of the images helps to develop the optimal treatment strategy.
