Epidemiology of concussions among United States high school athletes in 20 sports

Marar M., McIlvain, NM., Fields SK., Comstock JD., DR Comstock, American Journal of Sports Medicine. January 2012: ahead of print  

Concussions are a major health concern across many different sports. However, much of the research focuses on football despite evidence that women are at greater risk for concussions. Few authors have focused on comparing concussion rates within gender across sports. Therefore, the purpose of this study was to update and expand upon prior epidemiology studies by studying concussions among high school athletes across 20 sports. Information was analyzed from National High School Sports-Related Injury Surveillance System, High School Reporting Information Online. As part of the injury surveillance system, certified athletic trainers from high schools around the country reported injuries and exposures (playing/practice time per athlete) for 20 sports. This investigation describes the details of concussion injury patterns by sport in terms of severity (i.e., days lost), mechanisms, activities, symptoms, and amount of time for symptoms resolution. During the 2008-2010 seasons 1,936 concussions were reported during 7,780,064 athlete exposures. The injury rate was higher in competition (67%) than practice (33% of concussions). The majority of concussions were reported from participation in football (47%) followed by girls’ soccer (8%), wrestling (6%), and then girls’ basketball (5.5%). Concussion rate (number of concussions/number of exposures) was highest in football followed by boys’ hockey, and boys’ lacrosse. In gender comparable sports (e.g., soccer, basketball, what else?), girls had higher concussion rates than boys. The most commonly reported signs and symptoms were headache (94%), followed by dizziness (76%), difficulty concentration (55%), and then confusion (45%). Most common mechanism of concussion were player-to-player contact (70%) followed by player-player surface contact (17%). Athletes most commonly returned to play within 1 to 3 weeks (55%). Twenty-two percent returned in less than 1 week and 2% returned in less than 1 day.

Concussion rates vary by sport, gender, and exposure type (practice or competition). An understanding of concussion rates, patterns of injury, and risk factors can lead to a more specific education program of preventative measures for athletic trainers, referees, coaches, parents, and athletes to reduce the risk of concussions within high schools. This could lead to better protective equipment and regulatory efforts. Though there are some innate differences among sports, there were some consistent concussion variables across sports as well. For example overall concussion rates were higher during contests than in practice (except in cheerleading). Methods of reducing risk of player-to-player contact during game situations may help decrease concussion rates. This could be done via rule changes or more vigilant control over the rules in place. This is why it is important for referees to receive concussion education. Also, in all gender comparable sports (e.g., soccer) girls had higher concussion rates. Girls’ may have a biomechanical disadvantage, where they do not have sufficient neck strength to control deceleration of the head that could lead to a contra-coup brain injury. This difference in concussion rate could also be attributed to the recent discovery that girls may inheritably be more honest thus incorporating a reporting bias into the study. In addition concussed high school athletes on average missed more than 1 week of sports activity, no matter what sport they were playing. The concussion rate reported in this study was 13% of all reported injuries, which is higher than the last reported studies 5.5% (reported in 1999), 7.5% (reported in 2004), and 8.9% (reported in 2007). This possible trend in increasing concussion rates could be due to the inclusion of boys’ lacrosse and boys’ ice hockey or an increased awareness about the risk of concussions. This study also included concussions that led to time lost less than a day. However, this is a bit alarming since this violates the consensus that no high school athlete suspected of a concussion should to return to play on the day of the injury. Is your primary focus on concussion education within only high- risk sports? Do you believe rule changes are necessary to decrease concussion rates?

Written by: Jane McDevitt MS, ATC, CSCS
Reviewed by: Jeffrey Driban

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News Article of Interest:

Marar M, McIlvain NM, Fields SK, & Comstock RD (2012). Epidemiology of Concussions Among United States High School Athletes in 20 Sports. The American Journal of Sports Medicine PMID: 22287642