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 pre-season games, and the number of significant injuries that occur during preseason games is high.