Bodychecking is linked to a threefold higher risk of concussion and other injuries for 11- and 12-year-old hockey players, according to a new Canadian study meant to inform the debate on when checking should be allowed.

Researchers followed 1,108 peewee players in Alberta, where bodychecking is allowed and 1,046 players of the same age in a Quebec league that does not allow checking.

Researchers looked at injuries from bodychecking, elbowing, cross-checking, slashing and tripping. (Kevin Light/CBC)

Team trainers assessed injury rates during games, and the findings were published in Tuesday's online issue of the Journal of the American Medical Association.

If bodychecking was eliminated for the 8,826 players registered in Alberta peewee hockey, more than 1,000 game-related injuries per year and 400 concussions per year could be prevented, the study authors estimated after taking the amount of time played into account.

"I would argue that bodychecking is part of the game at certain levels of play," said study author Carolyn Emery, a sport epidemiologist at the University of Calgary.

"I think that the question at hand is whether or not all players that are 11- and 12-year-olds should be exposed to that particular element of the game in terms of the significant risk that we're seeing in those leagues, and the significant public health concern associated with the injuries that result from bodychecking," added the physiotherapist, coach and hockey parent.

Overall, the study showed bodychecking was associated with a threefold increased risk of all game-related injuries for 11- and 12-year-olds — including concussion, severe injury such as fracture close to a joint or severe concussion — that resulted in missing more than one week from hockey.

Players who suffered a previous injury or concussion, those in more elite levels of play, and athletes in the lowest 25th percentile for body weight were at significantly higher risk of injury than the rest of the players in the league, the researchers found.

The findings won't immediately change policy but will inform ongoing decision-making for Hockey Canada, which regulates minor hockey, Paul Carson, chair of Hockey Canada, said from Calgary.

"My feeling is that it's not that significant a number that there's a real concern at this point in terms of safety of youngsters playing the game," Carson said.

Aggression, skill differences

In the study, contact in hockey from elbowing, cross-checking, slashing and tripping also showed a more than double the risk of injury in the league that allows bodychecking, which suggests there was potentially greater aggression, said Emery, who is on sabbatical at the University of British Columbia in Vancouver.

Factors associated with bodychecking, such as skill development from playing a heads-up game, were not evaluated in the study.

There's a significant public health concern over injuries that result from bodychecking in peewee hockey, said study author Carolyn Emery. (CBC)

For example, elite level players might have a greater propensity to injury because they might take more risks, and these other factors need to be considered in minimizing the risks in youth hockey, Carson said.

Canadian data suggests hockey injuries account for 10 per cent of all youth sport injuries, the researchers noted.

Retired professional hockey player Keith Primeau, who has helped raise awareness about concussions in hockey, was asked what age is too young for contact hockey.

"I think there's some positives in it, in the sense the kids understand it, at a much younger age, they fear it less. But I also believe there's some truth to the fact that if you're getting hit in the head at an earlier age, especially repetitive times, then it could cause problems down the road," Primeau said.

Youth hockey players and their parents also continue to debate at what age bodychecking should start.

"There is a difference in the physicality and the momentum of the game," said Jonathan Hill, 11, of the Whitby Wildcats, who has played in leagues with and without bodychecking.

"As long as it's monitored properly and the kids are trained properly, then I think it's a part of the game," said mother Sylvia Hiller as she watched her 14-year-old play in Toronto.

In their next study, the researchers will compare the risk of injury in 13- and 14-year-old players at the bantam level in Quebec, where checking starts at that age, and Alberta, where they've had a couple of years' experience with bodychecking.