Hamstring injuries can be classified with regard to the site of involvement. Traumatic disorders at the proximal bone-tendon origin are best defined as avulsion injuries, such as ischial tuberosity fractures and hamstring tendon tears. Musculotendinous lesions include muscle strains and muscle contusions. Most hamstring injuries occur after in-direct trauma from excessive stretching or forceful contraction, leading to avulsion injuries or muscle strains and tears. Insufficient warm-up, lack of flexibility, inadequate muscle strength and endurance, or abnormal contraction and running may predispose to such injuries. In the event of blunt direct trauma, a muscle contusion, intramuscular hematoma, myositis ossificans, or compartment syndrome may develop.