The research, published in the February issue of Pediatrics, is thought to be the most comprehensive look at shoulder injuries to date in teen athletes.
Researchers say the study should help coaches and trainers identify settings where problems are most likely to occur. That way, they can begin to take steps to prevent serious shoulder injuries, which can have lasting and, in rare cases, career-ending consequences.
For the study, researchers used a national database to tally shoulder injuries to athletes participating in nine high school sports over seven seasons, from 2005 through 2012. Sports surveyed for the study included boys' football, wrestling and baseball; girls' volleyball and softball; and boys' and girls' soccer and basketball.
The good news is that shoulder injuries are relatively rare, although the shoulder is still the one of the most commonly injured joints.
During those years, there were about 2,800 reports of shoulder injuries sustained during more than 13 million times players took to the field for competition or practice. That's an overall rate of just over two injuries for every 10,000 athletic exposures, or more than 820,000 injuries nationwide.
But some players were more vulnerable than others.
Football players made up about half the total number of injuries seen in the study. Wrestlers were the second most frequently wounded group, accounting for about 15 percent of the total.
Players in all sports were more likely to damage their shoulders in competition, rather than practice. And football players were about six times more likely to hurt their shoulders during a game.
Sprains and strains were the most commonly reported injuries, followed by dislocations and bruises. Fractures accounted for about 10 percent of all injuries.
Boys were more likely to hurt their shoulders than girls, because they're more likely to play contact sports. In sports dominated by overuse injuries like basketball, baseball and softball, boys and girls had more equal chances of ending up with their arms in a sling.
"For the most part, these injuries are happening in male-dominated sports whose sole job is to make contact with other players, every single play," said study author Dr. T. Walker Robinson, a pediatric sports medicine specialist at Nationwide Children's Hospital in Columbus, Ohio.
Robinson said competition is often the setting for these injuries because it's where players are really pushing themselves and testing their limits.
An expert who was not involved in the research praised the study for giving doctors and parents a better idea of which competitors are most vulnerable.
"Studies like this really help to give numbers. You need a baseline before you can see if what you're doing to prevent injuries or treat injuries is working," said Dr. Joshua Dines, a sports medicine orthopedic surgeon at the Hospital for Special Surgery, in New York City.
"There's a lot of focus now on different training methods, more functional workouts," Dines said. "We theoretically know why these injuries occur, so then it's important to say, is that knowledge translating to decreasing these injuries occurring? We can't do that without these kinds of studies."
For more about common shoulder injuries, visit the American Academy of Orthopaedic Surgeons.