Researchers say the results suggest that many young varsity athletes may be under too much pressure to return to play before they've fully healed and aren't learning enough about injury prevention.
"It's shocking to me that high school kids have this rate of reinjury," says researcher Stephen Marshall, an associate professor of epidemiology in the University of North Carolina School of Public Health, in a news release.
He says lack of medical attention and resources at the time of injury and poor follow-up may be to blame. "Less than half of all high schools in the United States have even one certified athletic trainer," says Marshall.
The study of 15,000 high school athletes in North Carolina showed that football accounted for the largest number of injuries, followed by soccer. Injuries were also four times as likely to occur during a game vs. a practice session.
Repeat Sports Injuries Common
In the study, researchers followed boys and girls participating in 12 varsity sports at 100 high schools throughout North Carolina from 1996 to 1999.
Injuries were counted if they occurred in practices or games and if they resulted in limited play the day after the injury or required medical attention. Concussions, fractures, and eye injuries were counted regardless of severity.
The overall injury rate was about two per 1,000 games or practices, which is similar to the national rate of injuries among high school athletes found in a recent CDC study.
But researchers found the rate of injury was twice as high among those with a prior injury (two per 1,000 games or practices) compared with uninjured athletes (one per 1,000 games or practices). This increased with each additional year of playing.
The rate of injuries was highest among football players with an average of nearly four injuries per 1,000 exposures, followed by boys' soccer. The lowest injury rates were for track athletes.
Researchers found boys were 33 percent more likely to become injured than girls.
The results appear in the American Journal of Epidemiology.
SOURCES: Knowles, S. American Journal of Epidemiology, Sept. 29, 2006 advance access edition. News release, University of North Carolina, Chapel Hill. WebMD Medical News: "High School Sports Injuries Common."
By Jennifer Warner
Reviewed by Louise Chang