Lower extremity overuse injuries.

Increased number of overuse injuries, particularly of the lower extremity, occurs in exercise. It is important for the physician who prescribes exercise to understand the mechanism of injury-repetitive microtrauma-and the risk factors for occurrence of these injuries. In the lower extremity, risk factors include inappropriate progression of the rate, intensity and duration of training; anatomic malalignment; muscle-tendon imbalances of strength, endurance, or flexibility; shoewear; surface; and pre-existent disease states. Specific recommendations for training progression, technique, and sports equipment may have to come from the physician, since the recreational athlete often does not have access to coach or athletic trainer. These are described.