Muscle Injury: Pathophysiology, Diagnosis, and Treatment.

Skeletal muscle tissue has the largest mass in the human body, accounting for 45% of the total weight. Muscle injuries can be caused by bruising, stretching or laceration. The current classification divides these injuries into mild, moderate and severe. The signs and symptoms of grade I lesions are edema and discomfort; grade II, loss of function, gaps and possible ecchymosis; and grade III, complete rupture, severe pain and extensive hematoma. The diagnosis can be confirmed by ultrasound, which is dynamic and cheap, but examiner dependent; and magnetic resonance imaging (MRI), which provides better anatomical definition. The initial phase of the treatment consists in protection, rest, optimal use of the affected limb, and cryotherapy. Nonsteroidal anti-inflammatory drugs (NSAIDs), ultrasound therapy, strengthening and stretching after the initial phase and range of motion without pain are used in the clinical treatment. On the other hand, surgery has precise indications: hematoma drainage and muscle-tendon reinsertion and reinforcement.