Hamstring Injury

A hamstring injury (posterior femoral muscle strain, hamstring tear) is any injury to the hamstring muscles, the muscles in the back of the thigh.

The hamstrings, which extend the hip and bend the knee, are weaker than the opposing quadriceps (the muscles in the front of the thigh). If the hamstrings are not at least 60% as strong as the quadriceps, the quadriceps can overpower and injure them. A hamstring injury usually causes sudden pain in the back of the thigh when the hamstrings are contracted suddenly and violently, as can occur when a person sprints.

Immediate treatment includes rest, ice, compression, and elevation (RICE). A person should not run or jump but may jog in place, row, or swim--unless these activities cause pain--while the muscle heals. After healing begins, exercises to strengthen the hamstrings can help prevent a recurrence.

See the sidebar Strengthening the Hamstrings.