With just three months to go until the start of the World Cup, women's football has been rocked by a new wave of anterior cruciate ligament (ACL) injuries to star players

Last Friday, it was confirmed that England captain Leah Williamson will miss the tournament in Australia and New Zealand after rupturing her ACL during her club side Arsenal's 1-0 defeat to Manchester United in the Women’s Super League (WSL).

The 26-year-old defender is the latest unfortunate addition to a growing list of top names who have suffered similar injuries recently, including her Arsenal teammates Beth Mead – voted player of the tournament at Euro 2022 – and Dutch striker Vivianne Miedema, the all-time WSL top-scorer.

Bayern Munich and Germany star Guilia Gwinn is also in a race against time to be fit for the World Cup after tearing her ACL in October while Spain star Alexia Putellas has only just returned to full training with Barcelona after missing Euro 2022 with an ACL injury, along with France's Marie-Antoinette Katoto and Northern Ireland forward Simone Magill.

It was reported on Wednesday that Putellas' Barcelona teammate Lucy Bronze has undergone keyhole surgery on her right knee, although whether the operation was conducted with the potential for an ACL injury in mind is unclear.

After all, with female footballers "three to six times" more at risk of suffering such an injury than their male counterparts, according to a July 2021 study, the attraction of preemptive measures is understandable.

But why are women more susceptible to ACL injuries than men?

The ACL gender gap

Germany midfielder Sara Däbritz, who suffered the injury in 2019, says it is "important to invest even more in research, because the female body is different from the male body."

One of the authors of the aforementioned study was Joanne Parsons, an associate professor at the physical therapy department at the College of Rehabilitation Sciences of the University of Manitoba in Canada.

She told DW that biological factors, including hormones (particularly in puberty when ACL injuries in girls often occur), along with other biological and anatomical differences between the sexes (knee, thigh and hip shapes) undoubtedly play a part. However, they are far from the only reason for the disparity. Genetic factors and injury history are also highly relevant, but so are societal factors.

Parsons says scientists were once puzzled by the fact that annual ACL injury rates in the general population have decreased for males and stayed the same for females in recent years. Parsons believes a crucial piece of the puzzle has been ignored.

Inherent vs. acquired risk

"We need to think beyond the biological," she said. "So rather than [just] look at the inherent risk, we need to look at what kind of acquired risk they [women] are getting. What kinds of environments and exposures are they experiencing that may make them higher risk?

"I always default back to a weight-room analogy. There's been a fair bit of research done on girls and women in the weight room. It's a highly gendered environment where girls and women often don't feel welcomed or supported. So if we have an environment that doesn't really support strength training, which is highly relevant and needed for injury prevention, then we've created increased risk to athletes rather than it being an inherent risk."

ACL stops sport for some

Among other potential reasons for the different rates of injury are: the way in which girls and boys are encouraged to move by their parents or coaches (for example dancing vs. playing football) at a young age; that less visible pathways to professional sports mean that strength and conditioning training is perceived as less useful for young women; that women are offered surgery to resolve the issue less readily than men; and the fact that puberty is a danger point for girls injuring their ACLs, which stops many from carrying on with the sport.

Brooke Patterson among those who sustained an ACL injury at a young age, while playing basketball. She had to wait several months for surgery in her native Australia as her health insurance didn't cover the operation, a situation doubtless echoed around the world. She was eventually operated on, but now wonders whether it was even required. Some medical professionals and researchers now suggest rest, strength and conditioning, and allowing the muscle to heal may be equally effective in some cases.

Patterson went on to play in the women's Australian Football League (Aussie Rules) before becoming a physio and coach while studying for a PhD at the Sport and Exercise Medicine Research Centre at LaTrobe University, Melbourne.  

Coming back stronger after injury

She says that elite athletes, whatever their gender, will likely return to their sport after a minimum of about nine months, often better than ever. That's true of many players at the Euros.

"That's the biggest thing I've learned," Patterson told DW. "Seeing athletes, whether I'm coaching or rehabbing, become better athletically, and their football performance as well. Like most athletes who go through an ACL [injury], we have actually come out the other end a lot fitter and stronger."

Germany star Däbritz told DW before the Euros that this was the case for her, after she had her injury in December 2019.

"This injury made me even stronger — mentally, as a person — but also on the pitch," she said. "It helped me going through all of those challenges during the injury."

But it's often a different story for those who play recreationally, and many women are lost to sport after picking up such a serious injury at an early age.

"A lot of the community athletes don't really do rehab for as long as they should, or as frequently as they should. So if they don't return to sport, they're obviously not at risk of reinjuring, but they are at risk of early-onset arthritis. It's more of those general health things that those community athletes might not know about," Patterson said.

The lack of proper support structures can also have an impact on mental health for athletes, whether recreational or professional. Though it doesn't solve everything, the rapid professionalization of the top women's clubs and national teams may offer the likes of Magill, Katoto and Putellas more help than they would have received 20 years ago, or if they were playing lower down the sporting pyramid.

"I think it's a big reason why a lot of community athletes don't go back to sport — the trauma of the actual injury, it's super painful," Patterson said.

"The thought of having to do that again creates a lot of fears for people going back … they become very aware of their knee and sometimes people have persistent symptoms. It can really affect their confidence just to run and do normal everyday things."

The early days of injury and post-surgery can be particularly difficult, with mobility severely restricted. For Williamson, Mead, Miedema and Gwinn — as it was for Putellas, Katoto and Magill — watching their teammates play while they're largely immobile at home could make it even tougher.

Meanwhile, those seeking to address the gender disparity in ACL injuries hope future major tournaments will see their field of expertise crop up in the headlines less and less.

Edited by: Chuck Penfold and Matt Ford. This piece was first published in July 2022 and updated in April 2023.