What is a hamstring strain?
A hamstring strain involves an over-stretch or a tear of one or more of the 3 hamstring muscles at the back of the thigh – biceps femoris, semimembranosus, and semitendinosus. Strains can vary from a mild tightening of the muscle to a rupture of the muscle. The injury may affect the muscle or the tendon attachment to the bone at the base of the buttock.
Symptoms depend on the severity but can include sharp pain at the back of the thigh, muscle spasm, tenderness of the muscles, pain on stretching the leg, bruising over the site, and with severe tears, an inability to stand or walk. A gap may be seen or felt in the muscle. Classically, the person is accelerating or decelerating whilst running, and a sudden pain is felt in the hamstring region, which causes them to grab the back of their thigh.
A strain usually happens when the muscles become overloaded or try to move too fast in an explosive action such as jumping or sprinting. The injury usually occurs in the push-off phase of gait, or just before the foot hits the ground after the leg swings through while running.
Treatment of hamstring strains and tears
Treatment may involve:
- ice packs every couple of hours for a few days;
- elevation of the leg;
- anti-inflammatory medicines;
- an elastic compression bandage; and
- crutches – if you have difficulty walking.
In the case of severe injuries, an MRI may be performed to assess the severity of the injury, to ensure appropriate treatment is recommended.
Special exercises to regain strength and mobility and encourage the body to repair the damage correctly are an important part of rehabilitation. These can be prescribed by a sports physician or physiotherapist. Surgery may be needed to repair a complete avulsion (where the tendon is pulled off the bone) of the hamstring tendon. Surgery is rarely performed for muscle tears, and these usually heal well with the appropriate rehabilitation. In severe tears, the person may be left with a visible defect in the muscle, but this should not cause symptoms.