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.

Strengthening the Hamstrings Attach a 5-pound weight to the foot on the injured side and lie face down on a bed with the lower part of the body (from the waist down) off the bed and the toes touching the floor. Keeping the knee straight, slowly raise and lower the leg. Do 3 sets of 10 every other day. As strength returns, use increasingly heavier weights. This exercise strengthens primarily the upper part of the hamstrings. Attach a 5-pound weight to the foot on the injured side. Stand on the other leg. Slowly raise the weighted foot toward the buttocks by bending the knee, and lower it toward the floor by straightening the knee. Do 3 sets of 10 every other day. As strength returns, use increasingly heavier weights. This exercise strengthens primarily the lower part of the hamstrings.

Last full review/revision February 2003