Youth Ice Hockey Concussions Reported at US Emergency Department’s from 2002-2016: A Peak in 2011 and the Impact of Rule Modifications
Authors: Morrissey Patrick , Shah Neil V. , Hayden Andrew J. , Zhou Jack J. , Bloom Lee R. , Aylyarov Alex , Chatterjee Dipal , Newman Jared M. , McCarthy Matthew T. , Urban William P. 
Published: July 2019

Objectives: Ice hockey has one the highest incidences of concussions among youth sports. To combat this, several national campaigns have attempted to increase awareness since the early 2000’s. USA Hockey, the governing body for youth ice hockey in the US, also addressed the issue by instituting new checking rules in 2011. The new rules outlawed contact to the head at all ages and pushed the minimum age for body checking from 11 years old to 13 years old. The purpose of this study was to investigate the incidence of ice hockey-related concussions during a critical 15-year period from 2002-2016. We hypothesized that awareness campaigns would increase concussion reporting during the 2000’s and a 2011 rule change would decrease reporting. Methods: This is a descriptive epidemiological study utilizing the National Electronic Injury Surveillance System (NEISS). The NEISS was queried for all cases of concussion from January 1, 2002 to December 31, 2016 that included the product code 1279. Cases over the age of 18 and females were excluded. We reviewed the narrative text field and categorized each injury by mechanism (e.g. player contact, contact with boards, fall, etc). USA Hockey membership statistics were used to calculate population at risk and incidence. Incidences were reported per 10,000 person-years. Players were grouped by age according to USA Hockey divisions. Results: The national estimate of ice hockey-related concussions increased significantly from 656 in 2007 to 2,042 in 2011 (p<0.01). During the same period, the incidence increased significantly from 21.8 to 66.8 (p<0.05). After 2011, concussion incidence decreased significantly to 40.7 (p<0.05) and overall, the number of concussions decreased from 1,965 in 2012 to 1,292 in 2016 (p=0.055). The 13-14, 15-16, and 17-18 age groups drove both the increase and decrease in concussions over the study period. The gap in concussion incidence between the 11-12 and 13-14 age divisions widened significantly after 2011 (before 2011: 41 vs 49 (p=0.8); after 2011: 45 and 89 (p<0.01)). During the study period, incidence of concussion increased significantly with each successive age division. The incidences of concussion in the 0-8, 9-10, 11-12, 13-14, 15-16 and 17-18 age groups were 6.3, 22, 33.3, 59, 69.4, and 89.2, respectively. The top three mechanisms of concussion were player contact, falls and board contact. The incidence of concussion by player contact increased in each successive age division, especially between the 11-12 and 13-14 age groups (14.4 and 26.6 respectively, p<0.01). Conclusion: Ice hockey went through a monumental shift during the study period. From 2007-2011, concussion reporting increased significantly as players, coaches and parents became more aware and educated. In response, the rules of the game were changed in 2011 to outlaw hitting to the head and push back body checking to older divisions. Immediately after the rule changes in 2011, a significant decrease in concussion incidence occurred. Adding to this effect was the elimination of body checking in the 11-12 age division, which likely mitigated the rise of concussion incidence in that age group. Since we’ve shown that concussion incidence increases with age, it stands to reason that increasing the body checking age further would result in even decreased incidence of concussions. This study lends credence to the theory that rule changes aimed at protecting players can help decrease the incidence of concussions in youth ice hockey.