Hamstring injury

[Dave Paprocki]

The muscles in the back of the thigh (hamstrings) can be strained (hamstring pull) in any running activity.
(See also Overview of Sports Injuries.)
The hamstrings move the hip and knee backward. A hamstring injury often occurs when the hamstrings are contracted suddenly and violently, as can occur when a person sprints. It causes sudden pain in the back of the thigh. Hamstring injury can also develop more slowly, usually caused by inadequate flexibility training.
Doctors make the diagnosis based on the person’s symptoms and results of a physical examination. Sometimes magnetic resonance imaging (MRI) is also needed.