Background Concussion risk in ice hockey is amongst the highest for youth sport. To reduce this burden, in 2011 Hockey Canada implemented a national ‘zero tolerance for head contact (HC)’ policy mandating referees to penalize all player HCs; however, higher concussion rates have been observed following this policy in players aged 11–14.
Objective To compare HC rates and HC-policy enforcement in U15 (previously Bantam) ice hockey leagues before (2008–09) and after (2013–14) the ‘zero tolerance for HC’ policy implementation.
Design Prospective cohort.
Setting Calgary, Alberta, Canada.
Participants Thirty-two elite (upper 30% by division, allow body checking) U15 games pre (n2008–09=16, n=510 players) and post (n2013–14=16, n=486 players) HC-policy implementation.
Assessment of Risk Factors The 2011 HC-policy change mandates the penalization of any intentional or unintentional player/direct HC.
Main Outcome Measurements Dartfish video-analysis software with validated criteria for identifying HC types [direct HC (HC1), indirect HC (e.g., boards) (HC2)] and other player-to-player contact behaviours were used. Univariate Poisson regression [adjusted for cluster by team-game, offset by game length (minutes)] was used to estimate HC incidence rates (IR) and incidence rate-ratios (IRR) between cohorts.
Results A total of 506 HCs (n2008–09=261, n2013–14=245) were analyzed (IR2008–09=16.6/100 team-minutes; IR2013–14=15.5/100 team-minutes). The rate of HC1 (IRR=1.05, 95% CI: 0.86–1.28) and HC2 (IRR=0.74, 95% CI: 0.50–1.11) did not differ with the implementation of the HC-policy. Only 12.0% and 13.6% of HC1s were penalized pre- and post-policy respectively. Pre-policy, HC1s were commonly penalized as roughing or elbowing penalties (59%), while post-policy HC1s were penalized with the HC penalty (76%).
Conclusions Despite policy implementation for mandatory enforcement of direct HCs, there was no difference in the rate of HC1s and HC2s, or the proportion of HC1 penalized pre- and post-HC-policy enforcement. This research will be instrumental to inform Hockey Canada’s future referee training and rule enforcement modifications.