Over the last 12 months, the letters ‘ACL’ have almost become synonymous with women’s football. From Arsenal’s Beth Mead and Leah Williamson to Manchester United’s Gabby George and Chelsea’s Aniek Nouwen, the last two WSL seasons have been plagued by players sustaining injuries to their anterior cruciate knee ligament.

And now, for the first time, the issue is getting some investigation. Yesterday, UEFA announced it would be launching an initiative to investigate and better understand the prevalence of ACL injuries in the women’s game.

The plan, which will form the centrepiece of a wider ACL injury awareness campaign scheduled to launch at the end of next year, is the result of a recommendation from the European governing body’s recently established health expert panel. One of the group’s first steps has been to create an awareness questionnaire open to anyone affected by ACL injuries including players, coaches, physicians and physiotherapists.  

“Addressing the prevalence of ACL injuries in women’s football is crucial for the wellbeing of athletes and the advancement of the sport,” UEFA’s chief medical officer Zoran Bahtijarevic said. “UEFA’s proactive step in establishing a panel of experts reflects a commitment to understanding and reducing these injuries in the future.”

Up until now, experts have put forward several theories as to why the number of ACL injuries in the women’s game far surpasses the men’s. Research shows that female athletes are up to six times more likely to have a non-contact ACL injury than their male counterparts – but what’s going on here? Strong Women took a closer look at the story so far.  

To unpick why so many players are suffering from ACL injuries, we first need to understand what’s happening when they occur.

As one of the body’s main hinge joints, our knee is made up of three key bones: the thigh bone (femur), shin bone (tibia) and kneecap (patella). These bones are held together by four key ligaments, which stabilise the joint while allowing movement.

Two of these ligaments are known as cruciate ligaments, which sit deep inside the joint and cross over one another.

The ACL is one of these ligaments and is responsible for controlling rotational movement of the knee as well as preventing our shin bone from sliding in front of the thigh bone.  

It’s for this reason that sports which involve a lot of ducking, diving and twisting – such as football, netball, rugby and skiing – are most associated with ACL injuries. Sudden changes in direction can cause the ACL to overstretch and tear.

“ACL injuries can also be caused by excessive bending or straightening of the leg, a blow to the knee, twisting movements or awkward landings when jumping,” explains Saket Tibrewal, a consultant trauma and orthopaedic knee surgeon at Cromwell Hospital.

“Injuries to the ACL usually involve a popping sound and severe pain in the knee; it may feel unstable or give way, or feel like it will, and you may not be able to put any weight on it.” 

If we’re going to prevent more ACL injuries from occurring in the future, we need to understand why women are so much more likely than men to sustain this kind of injury. This is especially important for young athletes, who have seen the biggest increase in injuries.

Unfortunately, we don’t really know what the key issue is, but we do know that there are several factors that may contribute.

“It is thought to be a combination of multiple factors including structural differences and hormone levels,” Tibrewal explains.

“Women have a wider pelvis, which changes the mechanics of how the thigh bone, tibia and femur function. This puts more stress on the soft tissues that support the joints, and this higher stress can lead to either a chronic (overuse) or acute (sudden) injury.” 

Women typically have less muscle mass around their knees than men, too – and this can also lead to instability and a higher chance of tearing a ligament if the knee is overstretched.

Lastly, it’s thought that hormonal changes could play a role. “As oestrogen levels fluctuate through the cycle, this might make women more prone to injury when levels are higher,” Tibrewal adds. This is because higher oestrogen levels have been linked to increased joint stability.

The lack of certainty surrounding what causes the disproportionate number of ACL injuries in women is an issue in and of itself.

Indeed, as Mead highlighted during an interview with FIFPRO earlier this year, more research is needed to provide players and coaches with concrete information they can use to help prevent and treat injuries going forward.  

“I think it’s important that we as a collective try and get more done for ACLs and research into it,” she told the worldwide union for professional footballer players. “I think it is way too common in the women’s game. If that ever happened in the men’s game, a lot more would have been done sooner.”

She continued: “It’s important for us to drive the different factors and aspects around why it’s happening so often and it will be something that we’ll be delving into and pushing out there to try and get to the bottom of it.” 

While more research is needed to confirm what’s really driving the ACL injury epidemic, Tibrewal believes there are several changes which could be made to try and prevent injuries in the meantime.

On top of raising awareness of the problem to drive that research, he believes placing more emphasis on strength and conditioning training for younger players could help to protect younger athletes.

“Across all sports, integrated neuromuscular training programmes (biomechanical, neuromuscular control and strength training techniques) have effectively improved performance levels and decreased the risk of ACL injury,” he adds. 

At the end of the day, however, this crisis is indicative of a wider issue in women’s health: the lack of research into how female bodies function differently from our male counterparts.

With so few studies carried out into women’s bodies in particular, it’s hardly surprising they remain a mystery to experts. As the women’s game grows and excitement around the World Cup continues, we can only hope the hype leads to tangible progress. 

Images: Getty