O'TOOLE, M. L. Prevention and treatment of injuries to runners. Med. Sci. Sports Exerc., Vol. 24, No. 9 Supplement, pp. S360-S363, 1992. Key Points: 1) Many otherwise healthy runners are prevented from participating fully in their chosen endurance sport because of overuse injuries. 2) The most important risk factor for incurring an overuse injury is a training error, such as excessive mileage, sudden change in training distance or intensity, too much hard interval training, improper footwear, and running on cambered surfaces. 3) Although the knee is the most frequent site of injury in runners, any part of the lower extremity may be affected. 4) Tendinitis, muscle strain, and stress fractures are the most common overuse injuries in endurance athletes. 5) Prevention of injury through elimination of risk factors is clearly preferable to treatment. If injury does occur, treatment should include appropriate medical care, athlete education, cross-training, specific rehabilitative exercises, and a programmed return to running.