Background Ice hockey is a popular winter sport in Canada. Concussion accounts for the greatest proportion of all injuries in youth ice hockey. Research has informed policy change enforcing the no head contact rule in all leagues in Canada in 2011.

Objective To determine if the risk of game-related concussion and other injury differ for Pee Wee (ages 11–12) and Bantam (ages 13–14) players following a 2011 rule enforcement policy change compared to players in similar divisions prior to the rule change.

Design Historical cohort study.

Setting Ice hockey rinks.

Participants Historical cohort included Pee Wee (most elite 70%, 2007/08) (n=891) and Bantam (most elite 30%, 2008/09) (n=378) players before the rule change and Pee Wee (2011/12) (n=589) and Bantam (2011/12) (n=244) players in the same levels of play after the policy change.

Risk factor assessment Exposure of ice hockey teams before and after a “zero tolerance for head contact” rule enforcement policy change. Risk factors include position, and previous injury/concussion.

Main outcome measurements Suspected concussions were identified by a team designate (Pee Wee) or team therapist (Bantam) and referred to a sport medicine physician. Hockey injuries included those requiring medical attention and/or time loss.

Results Based on multivariate Poisson Regression (adjusted for cluster, exposure hours, position and previous injury/concussion) the risk of game-related concussion increased following the head contact rule enforcement change in Pee Wee (IRR=1.83 [95% CI; 1.18–2.86]) and Bantam (IRR=2.74 [95% CI; 1.41–5.32]). The risk of injury (excluding concussion) did not change in Bantam (IRR=1.03 [95% CI; 0.59–1.81]).

Conclusions The “zero tolerance for head contact or head checks” rule change did not reduce game-related concussion risk in Pee Wee or Bantam ice hockey players. This study will inform future research examining mechanism of injury leading to concussions in youth ice hockey.