Epidemiology of National Football League training camp injuries from 1998 to 2007

Background: Football is one of the leading causes of athletic-related injuries. Injury rates and patterns of the training camp period of the National Football League are unknown. Hypothesis: Injury rates will vary with time, and injury patterns will differ between training camp practices and preseason games. Study Design: Descriptive epidemiology study. Methods: From 1998 to 2007, injury data were collected from 1 National Football League team during its training camp period. Injuries were recorded as a strain, sprain, concussion, contusion, fracture/dislocation, or other injury. The injury was further categorized by location on the body. Injury rates were determined based on the exposure of an athlete to a game or practice event. An athlete exposure was defined as 1 athlete participating in 1 practice or game. The injury rate was calculated as the ratio of injuries per 1000 athlete exposures. Results: There were 72.8 (range, 58-109) injuries per year during training camp. Injuries were more common during weeks 1 and 2 than during weeks 3 to 5. The rate of injury was significantly higher during games (64.7/1000 athlete exposures) than practices (12.7/1000 athlete exposures, P < .01). The rate of season-ending injuries was also much higher in games (5.4/1000 athlete exposures) than practices (0.4/1000 athlete exposures). The most common injury during the training camp period was a knee sprain, followed by hamstring strains and contusions. Conclusion: Muscle strains are the most common injury type in practices. Contact type injuries are most common during preseason games, and the number of significant injuries that occur during preseason games is high.