{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,6]],"date-time":"2026-06-06T00:42:04Z","timestamp":1780706524504,"version":"3.54.1"},"reference-count":26,"publisher":"American Medical Association (AMA)","issue":"11","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAMA Netw Open"],"abstract":"Importance<\/jats:title>A rule prohibiting a direct hit to the lateral side of the head (ie, Rule 48\u2013Illegal 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.<\/jats:p><\/jats:sec>Objective<\/jats:title>To compare the incidence and proportion of concussions that occurred following hits to the head before and after the implementation of Rule 48.<\/jats:p><\/jats:sec>Design, Setting, and Participants<\/jats:title>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.<\/jats:p><\/jats:sec>Main Outcomes and Measures<\/jats:title>The incidence and relative proportion of concussion characteristics and mechanisms before and after the introduction of Rule 48.<\/jats:p><\/jats:sec>Results<\/jats:title>In the analysis of 688 concussions for NHL seasons spanning 2006 to 2010 (n\u2009=\u2009231) and 2014 to 2019 (n\u2009=\u2009457), 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,\u20090.6\/100 games [90% credible interval (CrI),\u20090.30\/100 games to 0.90\/100 games). There was also a reduction of 18.8 (90% CrI,\u200913.0-23.7) 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,\u20098.9-20.7 percentage points).<\/jats:p><\/jats:sec>Conclusions and Relevance<\/jats:title>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.<\/jats:p><\/jats:sec>","DOI":"10.1001\/jamanetworkopen.2023.44399","type":"journal-article","created":{"date-parts":[[2023,11,22]],"date-time":"2023-11-22T16:34:39Z","timestamp":1700670879000},"page":"e2344399","source":"Crossref","is-referenced-by-count":6,"title":["Concussion Characteristics in the National Hockey League Before and After the Introduction of Rule 48"],"prefix":"10.1001","volume":"6","author":[{"given":"Michael G.","family":"Hutchison","sequence":"first","affiliation":[{"name":"Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada"},{"name":"David L. MacIntosh Sport Medicine Clinic, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alex P.","family":"Di Battista","sequence":"additional","affiliation":[{"name":"Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Willem","family":"Meeuwisse","sequence":"additional","affiliation":[{"name":"National Hockey League, New York, New York"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jared M.","family":"Bruce","sequence":"additional","affiliation":[{"name":"Department of Biomedical and Health Informatics, University of Missouri\u2013Kansas City School of Medicine"},{"name":"Department of Neurology, University of Missouri\u2013Kansas City School of Medicine"},{"name":"Department of Psychiatry, University of Missouri\u2013Kansas City School of Medicine"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruben J.","family":"Echemendia","sequence":"additional","affiliation":[{"name":"Concussion Care Clinic, University Orthopedic Center, University of Missouri\u2013Kansas City"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J. Scott","family":"Delaney","sequence":"additional","affiliation":[{"name":"Department of Emergency Medicine, McGill University Health Centre, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul","family":"Comper","sequence":"additional","affiliation":[{"name":"Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada"},{"name":"Toronto Rehabilitation Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"10","published-online":{"date-parts":[[2023,11,22]]},"reference":[{"issue":"12","key":"zoi231295r1","doi-asserted-by":"publisher","first-page":"978","DOI":"10.1136\/bjsports-2016-097452","article-title":"What strategies can be used to effectively reduce the risk of concussion in sport? a systematic review.","volume":"51","author":"Emery","year":"2017","journal-title":"Br J Sports Med"},{"issue":"3","key":"zoi231295r2","doi-asserted-by":"publisher","first-page":"342","DOI":"10.1080\/00913847.2020.1836945","article-title":"Playing rule article eight decreases the rate of sport related concussion in NFL players over two seasons.","volume":"49","author":"Baker","year":"2021","journal-title":"Phys Sportsmed"},{"issue":"3","key":"zoi231295r3","doi-asserted-by":"publisher","first-page":"354","DOI":"10.1080\/00913847.2020.1718565","article-title":"Does the MLB\u2019s collision at home plate rule change prevent concussion injuries in catchers?","volume":"48","author":"Baker","year":"2020","journal-title":"Phys Sportsmed"},{"issue":"4","key":"zoi231295r4","doi-asserted-by":"publisher","first-page":"220","DOI":"10.1136\/bjsports-2019-101557","article-title":"Does reducing the height of the tackle through law change in elite men\u2019s rugby union (The Championship, England) reduce the incidence of concussion? a controlled study in 126 games.","volume":"55","author":"Stokes","year":"2021","journal-title":"Br J Sports Med"},{"issue":"15","key":"zoi231295r5","doi-asserted-by":"publisher","first-page":"948","DOI":"10.1136\/bjsports-2016-097217","article-title":"Head injuries in professional male football (soccer) over 13 years: 29% lower incidence rates after a rule change (red card).","volume":"53","author":"Beaudouin","year":"2019","journal-title":"Br J Sports Med"},{"issue":"11","key":"zoi231295r6","doi-asserted-by":"publisher","first-page":"2704","DOI":"10.1177\/0363546519861525","article-title":"Association between a rule change to reduce home plate collisions and mild traumatic brain injury and other injuries in professional baseball players.","volume":"47","author":"Green","year":"2019","journal-title":"Am J Sports Med"},{"issue":"8","key":"zoi231295r7","doi-asserted-by":"publisher","first-page":"547","DOI":"10.1136\/bjsports-2013-092234","article-title":"A systematic video analysis of National Hockey League (NHL) concussions, part I: who, when, where and what?","volume":"49","author":"Hutchison","year":"2015","journal-title":"Br J Sports Med"},{"issue":"2","key":"zoi231295r8","doi-asserted-by":"publisher","first-page":"125","DOI":"10.1136\/bjsports-2012-092059","article-title":"An observational method to code concussions in the National Hockey League (NHL): the heads-up checklist.","volume":"48","author":"Hutchison","year":"2014","journal-title":"Br J Sports Med"},{"issue":"8","key":"zoi231295r9","doi-asserted-by":"publisher","first-page":"552","DOI":"10.1136\/bjsports-2013-092235","article-title":"A systematic video analysis of National Hockey League (NHL) concussions, part II: how concussions occur in the NHL.","volume":"49","author":"Hutchison","year":"2015","journal-title":"Br J Sports Med"},{"issue":"11","key":"zoi231295r12","doi-asserted-by":"publisher","first-page":"838","DOI":"10.1136\/bjsports-2017-097699","article-title":"Consensus statement on concussion in sport: the 5th International Conference on Concussion in Sport held in Berlin, October 2016.","volume":"51","author":"McCrory","year":"2017","journal-title":"Br J Sports Med"},{"issue":"2","key":"zoi231295r16","doi-asserted-by":"publisher","first-page":"667","DOI":"10.1214\/20-BA1221","article-title":"Rank-normalization, folding, and localization: an improved R^ for assessing convergence of MCMC.","volume":"16","author":"Vehtari","year":"2021","journal-title":"Bayesian Anal"},{"issue":"2","key":"zoi231295r21","doi-asserted-by":"publisher","first-page":"389","DOI":"10.1111\/rssa.12378","article-title":"Visualization in Bayesian workflow.","volume":"182","author":"Gabry","year":"2019","journal-title":"J R Stat Soc Ser A Stat Soc"},{"issue":"24","key":"zoi231295r24","doi-asserted-by":"publisher","first-page":"3439","DOI":"10.1001\/jama.1985.03360240051033","article-title":"The National Football Head and Neck Injury Registry: 14-year report on cervical quadriplegia, 1971 through 1984.","volume":"254","author":"Torg","year":"1985","journal-title":"JAMA"},{"key":"zoi231295r25","doi-asserted-by":"publisher","DOI":"10.1136\/bjsports-2020-102072","article-title":"Use of the Sport Concussion Assessment Tool 5 (SCAT5) in professional hockey, part 2: which components differentiate concussed and non-concussed players?","author":"Bruce","year":"2020","journal-title":"Br J Sports Med"},{"key":"zoi231295r26","doi-asserted-by":"publisher","DOI":"10.1136\/bjsports-2020-102071","article-title":"Use of the Sport Concussion Assessment Tool 5 (SCAT5) in professional hockey, part 1: cross-cultural normative data.","author":"Echemendia","year":"2020","journal-title":"Br J Sports Med"},{"key":"zoi231295r10","first-page":"212","volume-title":"National Hockey League Official Rules 2010-2011","author":"National Hockey League","year":"2010"},{"key":"zoi231295r11","first-page":"223","volume-title":"National Hockey League Official Rules 2011-2012","author":"National Hockey League","year":"2011"},{"key":"zoi231295r19","volume-title":"ggplot2: Elegant Graphics for Data Analysis","year":"2016"},{"key":"zoi231295r13","unstructured":"Stan Modelling Language. Version 2.27. 2021. Accessed October 26, 2023. https:\/\/mc-stan.org"},{"key":"zoi231295r14","unstructured":"R: a language and environment for statistical computing. Version 4.1.0. R Foundation for Statistical Computing. 2021. Accessed October 26, 2023. https:\/\/www.r-project.org\/"},{"key":"zoi231295r15","unstructured":"RStudio: integrated development environment for R. Version 1.4.1717. PBC. 2021. Accessed October 26, 2023. https:\/\/dailies.rstudio.com\/version\/1.4.1717\/"},{"key":"zoi231295r17","unstructured":"rethinking: Statistical Rethinking book package. Version R package version 2.13. 2020. Accessed October 26, 2023. https:\/\/www.rdocumentation.org\/packages\/rethinking\/versions\/2.13"},{"key":"zoi231295r18","unstructured":"RStan: the R interface to Stan. R package version 2.21.2. 2021. Accessed October 26, 2023. https:\/\/mc-stan.org\/rstan\/"},{"key":"zoi231295r20","unstructured":"bayesplot: plotting Bayesian models. R package version 1.8.1. 2021. Accessed October 26, 2023. https:\/\/mc-stan.org\/bayesplot\/"},{"key":"zoi231295r22","unstructured":"Kay? M. tidybayes: Tidy data and geoms for Bayesian models. R package, version 3.0.4. 2023. Accessed October 26, 2023. https:\/\/mjskay.github.io\/tidybayes\/"},{"key":"zoi231295r23","unstructured":"GitHub. Hutchison-et-al-2023-JAMA-Open-Rule-48. Accessed October 31, 2023. https:\/\/github.com\/dibatti5\/Hutchison-et-al-2023-JAMA-Open-Rule-48-"}],"container-title":["JAMA Network Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/articlepdf\/2812265\/hutchison_2023_oi_231295_1700083527.41096.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,22]],"date-time":"2023-11-22T16:34:43Z","timestamp":1700670883000},"score":1,"resource":{"primary":{"URL":"https:\/\/jamanetwork.com\/journals\/jamanetworkopen\/fullarticle\/2812265"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,22]]},"references-count":26,"journal-issue":{"issue":"11","published-print":{"date-parts":[[2023,11,1]]}},"URL":"https:\/\/doi.org\/10.1001\/jamanetworkopen.2023.44399","relation":{},"ISSN":["2574-3805"],"issn-type":[{"value":"2574-3805","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,22]]}}}