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. 2023 Nov 1;6(11):e2344399.
doi: 10.1001/jamanetworkopen.2023.44399.

Concussion Characteristics in the National Hockey League Before and After the Introduction of Rule 48

Affiliations

Concussion Characteristics in the National Hockey League Before and After the Introduction of Rule 48

Michael G Hutchison et al. JAMA Netw Open. .

Abstract

Importance: A rule prohibiting a direct hit to the lateral side of the head (ie, Rule 48-Illegal Check to the Head) was introduced in the National Hockey League (NHL) in the 2010-2011 season and refined in the 2011-2012 season to widen the application to include direct contact to all areas of the head.

Objective: To compare the incidence and proportion of concussions that occurred following hits to the head before and after the implementation of Rule 48.

Design, setting, and participants: This retrospective cohort study used a before and after design to evaluate concussions among NHL players in regular season games. Data from the 4 seasons preceding the implementation of Rule 48 (2006-2007 to 2009-2010) were compared with data from 5 seasons following its implementation (2014-2015 to 2018-2019). Data were analyzed from October 31, 2021, to November 30, 2022.

Main outcomes and measures: The incidence and relative proportion of concussion characteristics and mechanisms before and after the introduction of Rule 48.

Results: In the analysis of 688 concussions for NHL seasons spanning 2006 to 2010 (n = 231) and 2014 to 2019 (n = 457), there was an overall increase in the incidence of concussion between the 2 time frames, although the incidence of concussions due to hits to the lateral aspect of the head decreased from 1.6/100 games to 1.0/100 games (estimated difference, 0.6/100 games [90% credible interval (CrI), 0.30/100 games to 0.90/100 games). There was also a reduction of 18.8 (90% CrI, 13.0-23.7) percentage points in the proportion of concussions due to hits to the lateral aspect of the head from 80 of 231 concussions (34.6%) to 61 of 457 concussions (13.3%). The incidence of concussions following hits to the head from body checks using the shoulder, arm, and glove was similar before and following the implementation of Rule 48. However, the proportion was reduced 14.7 percentage points from 113 of 231 concussions (48.9%) before to 149 of 457 concussions (32.6%) after implementation of Rule 48 (90% CrI of the difference, 8.9-20.7 percentage points).

Conclusions and relevance: The findings of this cohort study of NHL players suggest that after the introduction of Rule 48, the incidence rate and proportion of concussions from contact to the lateral aspect of the head decreased, as did the proportion of concussions following direct hits to the head.

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Conflict of interest statement

Conflict of Interest Disclosures: Dr Hutchison reported receiving consulting fees from the National Hockey League Players’ Association (NHLPA) during the conduct of the study and owning shares in Rhea Health Inc outside the submitted work. Dr Di Battista reported receiving consulting fees from the NHLPA. Dr Meeuwisse reported serving as the Chief Medical Officer for the NHL. Dr Bruce reported receiving personal fees from the NHL during the conduct of the study and receiving consulting fees from Sporting Kansas City, Med-IQ, and EyeGuide Inc and grant funding from Genzyme outside the submitted work. Dr Echemendia reported receiving consulting fees from the NHL, Major League Soccer, Princeton University Athletic Medicine, and the US Soccer Federation outside the submitted work; receiving grant funding from the NFL to Boston Childrens Hospital outside the submitted work; providing expert testimony in matters related to mild traumatic brain injury and sports concussion; and serving as the cochair of the NHL-NHLPA Concussion Subcommittee. Dr Delaney reported serving as Chief Medical Consultant for the NHLPA and Chief Medical Officer for CF Montreal. Dr Comper reported receiving consulting fees from NHLPA outside the submitted work and serving as the cochair of the NHL-NHLPA Concussion Subcommittee. No other disclosures were reported.

Figures

Figure.
Figure.. Difference in the Proportion and Incidence of Concussions Before and After Rule 48
The difference (contrast) in the proportion and incidence of concussions across characteristics relating to game situation, location, and mechanism in a cohort of National Hockey League players following the implementation of Rule 48 (2014-2019) compared with a cohort measured prior to its implementation (2006-2010). The vertical dotted line represents zero estimated difference between groups in both panels. A, Blue shading indicates the portion of the mass of the posterior distribution where there is a lower estimated proportion of concussions in the 2014-2019 cohort, while gray shading represents the portion of the mass of the posterior distribution where the proportion of concussions is higher in the 2014-2019 cohort. B, Orange shading indicates the portion of the mass of the posterior distribution where there is a lower estimated incidence of concussions in the 2014-2019 cohort, while gray shading represents the portion of the mass of the posterior distribution where the incidence of concussions is higher in the 2014-2019 cohort. Black dots represent the posterior mean estimate; the thicker black line, the 70% credible interval; and the thinner black line, the 90% credible interval. Plots are comprised of 4000 posterior sample draws. BC indicates body check.

References

    1. Emery CA, Black AM, Kolstad A, et al. What strategies can be used to effectively reduce the risk of concussion in sport? a systematic review. Br J Sports Med. 2017;51(12):978-984. doi: 10.1136/bjsports-2016-097452 - DOI - PubMed
    1. Baker HP, Lee CS, Qin C, Fibranz C, Rizzi A, Athiviraham A. Playing rule article eight decreases the rate of sport related concussion in NFL players over two seasons. Phys Sportsmed. 2021;49(3):342-347. doi: 10.1080/00913847.2020.1836945 - DOI - PubMed
    1. Baker HP, Volchenko E, Athiviraham A. Does the MLB’s collision at home plate rule change prevent concussion injuries in catchers? Phys Sportsmed. 2020;48(3):354-357. doi: 10.1080/00913847.2020.1718565 - DOI - PubMed
    1. Stokes KA, Locke D, Roberts S, et al. Does reducing the height of the tackle through law change in elite men’s rugby union (The Championship, England) reduce the incidence of concussion? a controlled study in 126 games. Br J Sports Med. 2021;55(4):220-225. doi: 10.1136/bjsports-2019-101557 - DOI - PubMed
    1. Beaudouin F, Aus der Fünten K, Tröß T, Reinsberger C, Meyer T. Head injuries in professional male football (soccer) over 13 years: 29% lower incidence rates after a rule change (red card). Br J Sports Med. 2019;53(15):948-952. doi: 10.1136/bjsports-2016-097217 - DOI - PubMed

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