Hamstring strains are common among runners. Athletes at risk include those with poor flexibility of the hamstring muscles, inadequate pre-participation warm-up, and previous injury. Older athletes are also at higher risk. As with any muscle strain, the amount of force that caused the muscle to tear determines the degree of injury.
The hamstrings are three posterior thigh muscles: the semimembranosus, the semitendinosus, and the biceps femoris.
Symptoms and Signs of Hamstring Strain
Strains of the hamstring muscles can manifest as an acute painful area in the posterior thigh when sprinting or running or develop more slowly, usually because of inadequate flexibility training.
Diagnosis of Hamstring Strain
The diagnosis is confirmed by finding hamstring pain with knee flexion against resistance as well as on palpation of the posterior thigh. In mild strains, tenderness and mild swelling are present. In more severe strains, ecchymosis, moderate to severe swelling, and poor muscle function caused by pain and weakness are present.
Treatment of Hamstring Strain
Rest, ice, and compression
Stretching, then strengthening exercises
Ice and compression with use of a thigh sleeve should begin as soon as possible. Nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics are prescribed as necessary, and crutches may be required initially if walking is painful.
Once pain begins to resolve, patients should begin gentle hamstring stretching. When the pain has completely resolved, gradual strengthening of the quadriceps and hamstrings is begun.
Only when satisfactory strength has been achieved should patients resume running. Athletes must be made aware that recovery from hamstring injury can often take up to several months, depending on the severity.