With an ever-growing variety of sports and exercise opportunities open to people of all ages, classes, and races, participation in casual sports has blossomed in recent decades, while interest in collegiate and professional sports has continued to soar. The field of sports medicine is thriving in response to the demand for health care professionals to care for people involved in vigorous exercise. Now more than ever, it is imperative that doctors, physical therapists, surgeons, nurses, and alternative medicine practitioners understand and are able to treat effectively the types of conditions stemming from all types of physical activity, ranging from pleasure walking to professional football.