Hamstring Strain

Hamstring strain is characterized by inflammation and pain in the back of the thigh along the hamstring muscles. There are three muscles that comprise the hamstring muscle group (the biceps femoris, the semimembranousus, and the semitendinosus), going from the hip or upper thigh across the back of the knee to the leg. This structure is important for bending the knee, straightening the hip, and helping stabilize the knee. It is also important for running and jumping. These tendons feel like ropes in the back of the knee. This is the most common injury of the thigh. Hamstring strains are usually grade one or two strains. A Grade 1 Strain is a mild strain. There is a slight pull without obvious tearing (it is microscopic tearing). There is no loss of strength, and the muscle-tendon unit is the correct length. A Grade 2 Strain is a moderate strain. There is tearing of fibers within the substance of the muscle or tendon or where the tendon meets the bone or muscle. The length of the muscle-tendon unit may be increased, and there is usually decreased strength. A Grade 3 Strain is a complete rupture.