A hamstring strain is an injury to the muscles in the back of the thigh. These muscles run from above the hip to the knee joint. A strain is a series of small tears in the muscle. The tendon attached to the muscle may also have some damage.

Hamstring strain is a common sports-related injury.

Posterior Thigh Muscles
Posterior Thigh Muscles
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A hamstring strain can be caused by:

  • Stretching the muscle too fast and/or too far.
  • Suddenly putting stress on the muscles when they are not ready for the stress.