The definitions of an acute injury and injury severity were similar to the criteria used by Powell and Barber-Foss21 in their studies on high school athletes.For this study,an ankle sprain was defined as trauma that (1) disrupted the ligaments of the ankle;(2) occurred during a coach-directed competition, practice, or conditioning session; and (3) caused the athlete to miss the rest of a practice or competition or miss the next scheduled coach-directed practice or competition.