Rule Modifications to Reduce Checking-Related Injuries in High School Boys' Lacrosse

The National Federation of State High School Associations previously implemented 2 lacrosse rule modifications: Rule 5.4 in the 2012-2013 academic year to heighten the penalty for a head or neck hit to the head, face, or neck (HFN) and Rule 5.3.5 in the 2013-2014 academic year to minimize body checking. To determine if the rates of overall injury, HFN injuries, and concussions due to intentional contact (checking) differed for boys' high school lacrosse players after Rule 5.4 and 5.3.5 modifications were enacted. Descriptive epidemiology study. Web-based online surveillance system. Boys' high school lacrosse players during the 2008-2009 to 2016-2017 seasons whose teams involved athletic trainers participating in the High School Reporting Information Online sports injury-surveillance system. Rule 5.4 in the 2012-2013 academic year increased the penalty for any intentional hits to the HFN, and Rule 5.3.5 in the 2013-2014 year eliminated body checking to a player in a defenseless position. Overall, HFN, and concussion injury rate ratios (IRRs) by checking mechanism; overall and checking-related injury ratios by competitions and practices. A decrease was shown in checking-related HFN injuries (IRR = 0.29, 95% CI = 0.13, 0.65) and checking-related concussions (IRR = 0.29, 95% CI = 0.12, 0.70) during practices in the seasons after both rule modifications were imposed, but no decreases occurred in any checking-related injuries during competitions. By injury mechanism, no decreases were evident after the Rule 5.4 modification. When both rule modifications (Rules 5.4 and 5.3.5) were enacted together, concussion rates due to delivering body checks (IRR = 0.51, 95% CI = 0.29, 0.91) and overall injury risk due to being body checked (IRR = 0.72, 95% CI = 0.53, 0.97) decreased. When both Rule 5.4 and 5.3.5 modifications were in effect, concussion and overall injury risks decreased for the body checker and the player being body checked, respectively.