In brief: To avoid the bias of injury studies based only on coaches' perceptions, four athletic trainers served in high schools in a two-year study to identify and evaluate all injuries resulting from athletic participation. There were 1,181 injuries in 3,049 participants in 19 sports. Sprains and strains accounted for two thirds of the injuries, and the most common injury was the ankle sprain. Thirty-nine percent of injuries were evaluated by a physician, and 25 injuries required hospitalization. The athletic trainers probably increased physician visits and x-ray examinations and sensitized the schools to the need for injury prevention, recognition, treatment, and rehabilitation.