Hamstring injury

Overview

A hamstring injury involves straining or pulling one of the hamstring muscles — the group of three muscles that run along the back of the thigh. These muscles are attached to bones by tendons. The hamstring muscles start at the sitting bone at the lower back of your pelvis or the back of your thigh bone. They end at the shinbone on the lower leg.

Hamstring injuries often happen in people who play sports that involve sprinting with sudden stops and starts. Examples include soccer, basketball, football and tennis. Hamstring injuries also can occur in runners, especially sprinters, and in dancers.

Self-care measures such as rest, ice and pain medicine are often all that is needed to relieve the pain and swelling of a hamstring injury. Rarely, surgery is needed to repair a hamstring muscle or tendon.

Symptoms

A hamstring injury typically causes sudden, sharp pain in the back of the thigh. There also might be a "popping" or tearing sensation.

Swelling and tenderness usually develop within a few hours. There might be bruising or a change in skin color along the back of the leg. Some people have muscle weakness or are not able to put weight on the injured leg.

When to see a doctor

Mild hamstring strains can be treated at home. But see a healthcare professional if you can't bear weight on the injured leg or if you can't walk more than four steps without a lot of pain.

Causes

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. The muscles are attached to the bone by tendons. The hamstring muscles make it possible to extend the leg back and to bend the knee. Stretching or overloading any one of these muscles beyond its limit can cause injury.

Risk factors

Hamstring injury risk factors include:

• Sports. Sports that require sprinting or running might make hamstring injury more likely. So might other activities that require extreme stretching, such as dancing.
• Earlier hamstring injury. People who have had one hamstring injury are more likely to have another one. This is especially true for people who try to go back to the same activities before the muscles have time to fully heal.
• Tired muscles, weak muscles and muscles that do not stretch well. Tired or weak muscles are more likely to be injured. Muscles with poor flexibility might not be able to bear the force of the action that certain activities require.
• Muscle imbalance. Muscle imbalance may lead to hamstring injury. If the muscles along the front of the thigh, called the quadriceps, are much stronger and more developed than the hamstring muscles, injury to the hamstring muscles might be more likely.
• Age. Risk of injury increases with age.

Complications

Returning to tiring activities before hamstring muscles are completely healed might cause the injury to happen again.

If the tendons attaching the muscles to the pelvis bone or the shin bone are completely torn off the bone, the hamstring muscles won't work as they should. Surgery may be needed to reattach the tendons.

Prevention

Being in good physical condition and doing regular stretching and strengthening exercises can lessen the risk of a hamstring injury. Try to be in shape to play your sport. Don't try to get in shape by playing your sport.

If you have a job that is physically demanding, staying in shape can help prevent injuries. Ask your healthcare professional about good exercises to do regularly to avoid injury.