Therapeutic exercise.

Physical activity provides the biologic stimulus for a number of body adaptive mechanisms and therefore is a potent force in both prevention and treatment of sports injury. It has been shown, however, that therapeutic exercise must be prescribed with precision and care if it is to be of optimal value. There are no "general" effects of exercise. The effects of exercise on the cellular structure of muscle, connective tissue, and the nervous system are specific to the intensity, duration, and frequency of exercise and dependent on the length of time after injury.