Hamstring Injuries

The hamstring muscles are located in the back of the thigh and injuries can be acute or chronic. Sprinting subjects these muscles to high tension loads and sudden tears can occur. The recent Olympic games in Atlanta saw several sprinters go down in agony with acute hamstring injuries. Conditions that predispose to acute injury are,
inadequate warm-up/stretching,
poor lower back flexibility, and
abnormal biomechanics (e.g., anterior pelvic tilt).

Chronic hamstring injuries usually arise from an improperly rehabilitated acute injury, but may occur as the result of small amounts of trauma repeated over a long period (i.e., distance running). Poor hamstring flexibility increases the likelihood of small tears, which in turn cause the muscle to shorten and get tighter. A vicious circle can become established. Prompt and appropriate initial treatment can break this spiral.
The initial care of an acute hamstring injury involves the R.I.C.E. regimen. This acronym stands for,

rest,
ice,
compression (e.g., an ace bandage), and
elevation.