With the increasing focus on tackling obesity and other lifestyle-related illnesses and conditions, participation in sports and physical activity is growing. The consequences are that injuries and unwanted side-effects of healthy activity are becoming major health problems. Prevention is crucial to health gain, both in the short-term (preventing immediate injury), and in the longer term (reducing the risk of recurrence and prolonged periods of impairment). Prevention follows 4 main steps: 1) the sports injury problem must be described in incidence and severity, 2) the etiological risk factors...