Both boys’ and girls’ LAX players catch a hard, rapidly moving ball using a stick with a webbed head frequently positioned near the player’s head to maintain ball possession, but substantial differences between the sports exist, with the sphere rule intended to protect against stick strikes to the head in girls’ LAX (Kelley 2018; US Lacrosse n.d.-b). Unfortunately, our observations indicate the sphere rule, as currently enforced, does not effectively prevent concussions resulting from contact with a stick in girls’ LAX. Thus, any increase in concussions sustained by stick or ball contact in girls’ LAX compared to boys’ LAX can reasonably be assumed to be related to the fact that girls are less protected from stick or ball impacts to the head because they are not allowed to wear the hard shell helmet mandated in boys’ LAX.
Based on our findings, playing girls’ LAX is a risk factor for concussion from stick or ball impacts. The rate of concussions sustained from stick or ball contact was 2.60 times higher among girls than boys. Additionally, the AR% indicates 61.5% of concussions sustained from stick or ball contact in girls’ LAX were attributed to girls not wearing the same hard shell helmet mandated in boys’ LAX. Thus, we estimate 44.7% of all concussions in girls’ LAX could have been prevented if girls were also required to wear these helmets. Even if better enforcement of the sphere rule could effectively prevent all stick strikes, when we looked only at the effectiveness of headgear in preventing concussions sustained from contact with the ball, we estimated nearly a quarter of all concussions in girls’ LAX could have been prevented if girls wore the same helmet required in boys’ LAX. Our study appears to be the first to utilize the AR%, a tool which can be used to drive targeted prevention efforts by identifying what percent of an outcome of interest can be attributed to one risk factor compared to others (Peterson et al. 2013; McKinney et al. 2017), to evaluate the effectiveness of a specific piece of protective equipment in reducing sports related injury, in this case evaluating headgear rules in high school LAX.
For nearly three decades whether the helmets required in men’s/boys’ LAX should also be required in women’s/girls’ LAX has been debated in the lay media (Pennington 2016; Miele 2017), by policy makers (Bull and Cavanaugh 2016; NFHS 2019b), and in discussion sections of peer-review publications (Lapidus et al. 1992; Harmer 1993; Diamond and Gale 2001; Otago et al. 2007; Dick et al. 2007; Lincoln et al. 2007; Xiang et al. 2014; Warner et al. 2018; Pierpoint et al. 2019a, 2019b). This ongoing debate motivated Acabchuk and Johnson to publish a manuscript which included a table titled “Relevant evidence to counter each argument against the use of helmets in women’s lacrosse” which described several arguments against helmets and, for each, provided “Evidence and/or arguments against rationale” (Acabchuk and Johnson 2017). The fact that hard shell helmets with full face masks are mandated for males demonstrates LAX sport’s US governing bodies (e.g., US Lacrosse, NCAA, NFHS) have acknowledged that male players are at risk of head/face injury, including concussion, and that they believe the hard shell LAX helmet is effective at reducing injury risk. Prior studies have demonstrated female LAX players are also at risk of head/face injury, including concussion (Marar et al. 2012; Warner et al. 2018; Barber Foss et al. 2018; Pierpoint et al. 2019a, 2019b). The main gender difference in LAX concussions is not the incidence of injury, but rather the mechanism of injury, with males most often sustaining concussions from athlete-athlete contact and females most often sustaining concussions from stick or ball contact (Lincoln et al. 2007; Xiang et al. 2014; Warner et al. 2018; Pierpoint et al. 2019a, 2019b). Although the hard shell helmets mandated in men’s/boys’ LAX have been demonstrated to be effective at reducing head injury potential from ball strikes (Rodowicz et al. 2015), these helmets are still prohibited in girls’ LAX (US Lacrosse n.d.-b). So, why aren’t females also required to wear this effective protective equipment?
“Sports culture” can be a serious impediment to athlete health and safety interventions, even when the intervention is a piece of effective and readily available protective equipment. A historical example relevant to the debate over LAX headgear is eye protection in field hockey. In 2004, the American Academy of Pediatrics and the American Academy of Ophthalmology recommended that protective eyewear be worn by all participants in sports like field hockey (AAP 2004). In the 2011–12 academic year, the NFHS mandated protective eyewear in field hockey (NFHS 2018), and research demonstrated the eyewear mandate in high school field hockey effectively reduced injury without unintended consequences (Kriz et al. 2012; Kriz et al. 2015). However other US field hockey governing bodies have resisted following the NFHS’ lead. People deeply embedded in sports culture often argue against changes in protective equipment due to fears that such measures will either change the culture of the sport, or unintentionally increase injury rates. Given the continued presence of these concerns despite a lack of supporting empirical data, we believe an evidence-based discussion surrounding the controversial issue of use of helmets in the context of girls’ LAX is warranted.
As noted above and in the introduction, epidemiologic research clearly shows girls’ LAX players sustain head/face injuries, including concussions. Further, because women’s/girls’ LAX rules mandate eyewear and mouthguard use, and as of 2017, allow the optional use of headgear meeting a new standard “developed to decrease ball-to-head and stick-to-head impact forces” (US Lacrosse n.d.-a; US Lacrosse n.d.-b), US LAX itself acknowledges that female LAX players are at risk of head/face injury and that the incidence and/or severity of such head/face injury may be reduced through use of protective equipment. It follows logically that if female LAX players are sustaining blows to the head/face that place them at risk of eye or dental injuries, these same blows to the head/face may also place them at risk of other head/face injuries, including concussion.
Our results show that allowing helmets in girls’ lacrosse would lower risk of concussion due to contact with the stick or ball. However, a real concern for public health professionals, shared by those in the sports community, is that in the process of implementing efforts to prevent one health issue, a new health issue may inadvertently be introduced or other health issues may be exacerbated. The only way to determine whether this concern is valid is to measure the prevalence of potential consequences before and after an intervention. In girls’ LAX, such research has been precluded to date because helmets are not allowed, though we can draw expectations from surrogates. For example, mandating hard shell helmet use in male LAX did not lead to an unacceptable level of unintended consequences because these helmets are still mandated, and retaining the helmet mandate if it had increased rather than decreased injury risk would have been unethical. We can reasonably conclude that introducing helmets in female LAX would likely not unacceptably increase injury risk if it did not do so in male LAX. A similar argument (that protective eyewear would actually increase injury risk) raised in opposition to the mandate of eyewear in female LAX, was proven unfounded by research showing no unintended consequences followed the eyewear mandate (Lincoln et al. 2012). Additionally, studies of the introduction of a high school field hockey eyewear mandate showed decreased injury rates without unintended consequences (Kriz et al. 2012; 2015). Finally, we can look at research on other sports such as a study of skiing and snowboarding injuries which concluded helmets clearly decreased risk of injury without any unintended consequences such as increased neck injuries (Haider et al. 2012). Although we should not expect an unacceptable increase in injuries if hard shell helmets are mandated in girls’ LAX, the only way to conclusively evaluate this concern is to introduce hard shell helmets and then monitor for unintended outcomes. If unintended consequences are observed, then hard shell helmets should be not be required.
An argument, frequently referred to as the “gladiator effect,” posits that once protective equipment is donned, athletes will feel a false sense of security and will play more aggressively and take greater risks, thus increasing injury rates. For example, the NFHS’ Soft Headgear in Non-Helmeted Sports Position Statement reads, “The use of soft headgear may produce unintended consequences, including providing a false sense of security to athletes. While a recent study shows that the use of soft headgear in soccer players did not result in an increase in other injuries, a false sense of security may result in athletes, coaches, and parents/ guardians, placing less emphasis upon other strategies that include, but are not limited to: avoidance of head impact and foul play, concussion education, and the immediate reporting of concussion symptoms.” (NFHS 2019b). There do not appear to be peer-reviewed publications reporting evidence to support this argument. Rather, a body of refuting evidence concludes there is no increase in risk taking behavior and/or injury rates associated with use of protective equipment (Lund and O’Neil 1986; Scott et al. 2007; Cusimano and Kwok 2010; Ouellet 2011; Haider et al. 2012; Ruedl et al. 2012; Brunner et al. 2015; Ruedl et al. 2019). The most pertinent examples include an RCT which found no increase in injuries, including concussion, among high school soccer players randomized to wear headgear (McGuine et al. 2019) and a study of the eyewear mandate in girls’ LAX which concluded “overall injury rates do not indicate rougher play with introduction of protective equipment” (Lincoln et al. 2012). Additionally, because hard shell helmets are still mandated in boys’ LAX, no appreciable gladiator effect resulting from their adoption must have occurred. Further, there is no evidence that females, traditionally described as playing less aggressively than males, would be expected to become more aggressive than their male counterparts should they be allowed to wear helmets. Also, if athletes truly believed protective equipment could enable them to play harder, we would expect near universal adoption of optional equipment because athletes want to play at their highest level. Yet, across sports, few athletes adopt optional protective equipment (e.g., few baseball pitchers wear head protection, few rugby players wear scrumcaps, few college field hockey players wear eyewear, and to date few female LAX players wear the newly available headgear). Finally coaches and officials have the ability to control rough/reckless play through reprimands, penalties, game ejections, and suspensions – in other words, by enforcing the rules. In short, the only way girls’ LAX players could exhibit the gladiator effect is if LAX coaches, officials, and policy makers allow them to violate the rules of play.
Finally, both sexes play with hard, fast moving lacrosse balls and sticks, yet headgear standards are vastly different. Although US LAX governing bodies have revised their rules to allow females to wear an optional piece of protective equipment (a flexible headgear), with the intention of reducing impacts due to ball and stick contact, they do not mandate their use. There is no evidence to indicate the hard shell helmet with full face mask currently mandated in boys’ LAX would not provide similar protection from stick and ball strikes in girls’ LAX, thus making irrelevant the new flexible headgear.
Like all studies, ours had limitations, largely associated with the data source. High School RIO captures LAX data from a convenience sample of schools with ATs and thus, our findings may not be generalizable to all US high schools with LAX teams. Concussion reporting was at the discretion of the individual AT and a uniform study definition of concussion was not provided, which may lead some to question the accuracy of the reported concussion data. However, ATs have proven to be highly reliable reporters of sports-related injuries, particularly concussions (Lombardi et al. 2016). In High School RIO, exposures are captured as number of AEs rather than hours or minutes of participation which prohibits more exact time-based injury rates. It is not reasonable to expect high school ATs, who are not present at all practices and competitions for all sports, can accurately capture minutes of practice and competition exposures for all athletes in all sports.
An additional limitation is our inability to evaluate the recent introduction of the optional flexible shelled LAX headgear on concussion rates in girls’ LAX. The headgear was first marketed in 2016, and US LAX only made it the only option for players seeking head protection in 2017 (prior to that girls’ LAX players could wear soft headgear designed for other sports). Between the product’s newness and the fact that its use is only optional, it is unclear whether or not the flexible shelled headgear is protective against concussions from stick and ball impacts. If epidemiologic studies establish that the flexible shelled headgear is effective, it should be mandatory protective equipment. To date, no evaluation of the effectiveness of this optional piece of equipment in preventing concussion has been published in the scientific literature.
Despite these limitations, this study contributes important information to the body of knowledge on the relative risk of concussion in girls’ and boys’ LAX and is novel for utilization of the AR% to evaluate concussions resulting from ball or stick impacts associated with the different gendered helmet rules.