Hamstring Injuries

Background

People involved in skiing, dancing, weight lifting and football may be at risk for these types of injuries.  The hamstring muscle group of muscles consists of three muscles that run from the bottom of the pelvis bone (ischium) to the shin bone (tibia).  They help you walk and to extend the hip and to flex the knee.

Risk Factors for Injury

Numerous risk factors have been suggested, including improper warm-up before sports, strength imbalances in the leg, lack of core muscle strength and stability, fatigue, and history of previous injury.  There is some controversy regarding flexibility as a risk factor.

Mechanism of Injury

Hamstring injuries can occur proximally (where the muscle attaches to the pelvis), in the middle (where muscle joins tendon), and distally (where the tendons attach to the shin bone).  Most commonly, injuries occur in the middle where the muscle fibers join the tendon.  The most severe injuries can occur when the tendon avulses from the pelvic bone.

Symptoms

A sharp pain or popping sensation in the buttock and upper leg that occurs during physical activity.  There can be significant bruising that occurs within the first 24-48 hours after injury down the back of the leg.  Often, there is discomfort with walking and sitting.  You may notice weakness with knee bending in cases of complete rupture.

Examination

The thigh is checked for bruising and injuries that may occur to the hip or knee.  Strength and motion is assessed.   A single x-ray of the pelvis may be taken to ensure there are no fractures or bony avulsions of the hamstrings.

Treatment

The majority of hamstring injuries can be treated without surgery.  Injuries to the area where muscle and tendon join are treated with activity modification, rest, ice and anti-inflammatories.  For tears from the pelvic bone, treatment depends on the severity of the injury.  As a general rule of thumb, if there is injury to 2 or more of the tendons that pull away from the bone by >2 cm, surgical re-attachment may be considered.  Surgical treatment consists of a small incision below the buttock where small anchors and sutures are used to re-attach the tendons back down to the bone so they can heal.  The patient wears a protective hip brace after surgery to restrict motion and allow for healing.  Physical therapy usually begins around 5 weeks after surgery once healing has occurred.