Women are at greater risk of concussion than men, head trauma experts warn as the major codes ramp up their focus on women's leagues.
A growing body of research internationally suggests female athletes are more likely to suffer concussion from less brutal blows and report more symptoms than male athletes.
As football codes embark on a massive recruitment drive for female players, their organisations and the broader community need to improve the surveillance and responses to concussion at every age and competition level, said Dr Alan Pearce at La Trobe University.
Every major football code in Australia is chasing the hearts and minds of young women and girls. In the space of two years, rugby union, rugby league and AFL have either launched or announced new domestic women's competitions, in the form of the Aon7s universities competition, Super W, the NRL Women's Premiership and the AFLW.
Dr Pearce said it was crucial that women's leagues do not repeat the mistakes their male counterparts did in the 1980s and 1990s, when concussion was seen as a "badge of honour".
"The anecdotal evidence we're getting from AFLW observers is that the players are trying to impress and show how strong and athletic they are.
"They're great athletes, but they've had less of an opportunity to [develop safe] tackling skills than the boys, who started at much younger ages," he said.
Last year, AFLW star Daisy Pearce said she noticed an "unprecedented physicality and intensity, almost at the expense of regard for personal safety" in the early rounds of competition.
"My guess is many players felt they had a point to prove," said Pearce, who last year publicly spoke of her own "nasty concussion" and why the physicality of AFL was a big part of why she loved the sport.
Dr Adrian Cohen at the University of Sydney said a lack of robust concussion research overall meant it was not clear what caused the reported gender disparities, but researchers suspected genetic predisposition left women more susceptible.
The fact that women often came to contact sports later in life than male athletes meant they had less time to develop protective musculature – particularly at head and neck – and had fewer opportunities to hone safe tackling techniques.
"We should be encouraging more research to address these questions, so we don't have people making sensationalist claims [like] women suffer catastrophic injuries that will discourage women from playing these sports," Dr Pearce said.
Emerging evidence also suggested women were more likely to report concussion symptoms, whereas men were more likely to play them down.
An increased risk of concussion should not deter women and girls from playing contact sports, Drs Pearce and Cohen said.
Quite the opposite. Attracting girls at younger ages to the sports would give them more of an opportunity to develop the protective musculature and tackling techniques that could help ameliorate the risk.
But organisations at every sporting level needed to ensure women and girls were given the same focus on protection and responses for concussion as their male counterparts, they said.
Jillaroo fullback Sam Bremner spent five weeks off the field after she fell and hit her head during a training session in April last year.
"I was knocked out but I didn't have any symptoms like headaches or nausea … the NRL doctor said 'we still don't want you to play'," Bremner said.
"If you'd asked me then whether the NRL took concussion seriously I would have blown up ... I would've said they were really strict, because I wanted to play … but you can't take your head for granted," she said.
"We do so much training and strength work and conditioning for this game ... We are so educated about [concussion]. We're told not to be brave and think we could play on … they actually encouraged us to come off the field."
Bremner and her teammates also undergo cognitive testing to monitor any changes that may occur after hard hits.
Dr Cohen said the top-level female teams usually had comparable protocols and medical personnel to those of the elite male teams, but that support fell away in the lower-level and amateur female competitions.
"Where we are for women, it's not close to the same level as the men," Dr Cohen said.
"We can all do more by being aware of concussion and design specific programs to increase education among players, parents, coaches, organisations, schools and viewers," Dr Cohen said.
Concussion researcher at Monash University Dr Catherine Willmott said the lack of robust studies that controlled for other factors such as family history and lifestyle (including alcohol consumption) meant "the jury is still out" when it came to assessing the risk factors and effects of concussion on the brain in the long term.
"We'll need five to ten years to conclusively answer these questions," Dr Willmott said.
Much of the gender-based research was based on US and European studies of women in ice hockey, lacrosse and soccer. It was only now as codes continue to ratchet up women's league offerings that researchers will have the opportunity to strengthen our understanding of the gender differences in concussion risk in Australia, she said.
A spokesperson for the NRL said it was currently working through their women's protocols for concussion, which would be based on international best practice.
A spokesperson for the AFL said the league was conducting research into the effects of concussion in both the women's and men's leagues, including the annual surveillance of concussion cases and an investigation into the efficacy of headgear.
"Clubs are also sent periodic updates to encourage coaching of appropriate protective actions for players and the minimisation of head contact," the spokesperson said in a statement.
The league also hope to promote the HeadCheck app to underage leagues, which provided information about the management of children suspected to have been concussed.
A Rugby Australia spokesperson said rugby's laws reinforced the rule that the "head is sacred" and the sport had strictly enforced high tackle rules.
"At every professional game there is a Head Injury Assessment Doctor, to manage the issue of concussion on field, independent from team medical staff," the spokesperson said.
This year the code will introduce the Blue Card System for all Rugby Australia competitions that gives referees the power to remove players from the field who they believe may be showing symptoms of concussion.
With Tim Cowie and Georgina Robinson