A hamstring injury is a strain or tear to the tendons or large muscles at the back of the thigh. It is a common injury in athletes and can happen in different severities. The hamstring muscles are a group of three muscles that run along the back of the thigh from the hip to just below the knee. These muscles make it possible to extend the leg back and to bend the knee. Hamstring injuries often occur in people who play sports that involve sprinting with sudden stops and starts, such as soccer, basketball, football, and tennis. They can also occur in runners and dancers.

Symptoms of a hamstring injury include a sudden, sharp pain in the back of the thigh, swelling, tenderness, bruising, or a change in skin color along the back of the leg. Some people may also experience muscle weakness or not be able to put weight on the injured leg. Mild hamstring strains can be treated at home with self-care measures such as rest, ice, and pain medicine. However, it is important to see a healthcare provider if you cannot bear weight on the injured leg or if you cannot walk more than four steps without a lot of pain.

Hamstring injury risk factors include returning to tiring activities too quickly, poor conditioning, muscle fatigue, and choice of activity. Regularly doing stretching and strengthening exercises, and warming up before exercise, may help reduce the risk of injuring your hamstring. Most hamstring strains heal very well with simple, nonsurgical treatment such as RICE (rest, ice, compression, and elevation). However, in severe cases, surgery may be necessary to repair a hamstring muscle or tendon.