Effects of time in competition, phase of play, and field location on injury severity in high school football

Over 1 million United States (US) high school athletes play football. This study evaluated the effects of competitive intensity, represented by the variables time in competition, phase of play, and field location on injury severity among these athletes. Football-related injury data were collected during the 2005-06 school year from 100 nationally representative US high schools via High School RIO™ (Reporting Information Online). A weighting algorithm was used to calculate national injury estimates. Nationally, high school football players sustained an estimated 280,919 competition injuries during the 2005-06 school year. The rate of injury per 1,000 athlete-exposures was higher in competition (12.09) compared to practice (2.54) (RR=4.75, 95% CI: 4.34-5.20). The majority of competition injuries were mild (48.0%), with fewer moderate (32.3%) and severe (19.8%). Mild and moderate injuries were typically lower leg/foot/ankle sprains/strains (19.5% and 21.7%, respectively) and concussions (8.5% and 21.0%, respectively), while severe injuries were typically knee strains/sprains (22.3%) and arm fractures (21.4%). Compared to injuries sustained during the end/overtime of games, a greater proportion of injuries sustained during the beginning and middle were severe (IPR=1.83, 95% CI: 1.25-2.69). Compared to injuries sustained during general play, a greater proportion of injuries sustained during kickoff/punts were severe (IPR=1.69, 95% CI: 1.07-2.68) and were concussions (IPR=1.86, 95% CI: 1.05-3.30). Injury severity and diagnosis varied little by field location. Identifying factors contributing to severe injury is a crucial first step towards developing targeted evidence-based interventions aimed at reducing the incidence of severe injuries among the millions of high school football players.