Leah Williamson: Why are so many female footballers suffering ACL injuries?

Not another.

When England captain Leah Williamson went down in agony during Arsenal's defeat by Manchester United on Wednesday, onlookers were already fearing the worst.

Two days later it was confirmed - another of the world's best female players had suffered an anterior cruciate ligament (ACL) injury, regarded as one of the worst injuries to have as a footballer.

The 26-year-old defender s an ever-expanding list which includes her Arsenal team-mates Beth Mead, who was the Euro 2022 player of the tournament, and Vivianne Miedema, the Women's Super League's all-time top scorer.

Once again, there are renewed calls from players, fans and managers for more research into why this type of injury is more prevalent in female footballers than male.

England striker Chloe Kelly has said the "fear" and "negativity" around ACL injuries "needs changing". So what is being done to try and reduce the risk?

Research has long suggested that ACL injuries - the most serious kind of knee damage - are more prevalent in female footballers, with estimates ranging from two to eight times more likely than in male.

Dr Katrine Okholm Kryger, a senior lecturer in sports medicine at St Mary's University in London who specialises in football, said recent discussions have focused on whether the injury risk is sex related - the female anatomy and hormones, or whether it could be gender related - the way female athletes are raised and managed compared to male athletes.

"I think there's some truth in all of these areas," she said.

"We have to be really careful when we talk about this in women's football because there is a tendency within research and within the media of being like 'oh, women are so unstable, fragile, because of their anatomy, their hormonal fluctuations' but we haven't proven that is the cause of these injuries.

"Maybe it is the way we're treating women. I'd like to see that changed in people's perceptions of female athletes and women's football in general."

1. Anatomy/biomechanics

The physical differences between men and women, such as women generally having wider hips, which increase the leg's angle into the knee, and under-developed muscles which prevent the knee from turning in upon landing, have been the subject of research looking at whether that increases the risk.

However, Dr Okholm Kryger says that there is no strong evidence from the research that this is the main risk factor.

2. Hormones

The role of the menstrual cycle has also been put forward as potentially making females more predisposed to injury at certain times. During the menstrual cycle when oestrogen is elevated, which usually happens in the second week, it can affect the stability of ts, making them looser and more lax.

However, Dr Okholm Kryger is keen to stress that there is a lack of research to whether this increases the risk of injury. "There has been some not very high quality research done on the relationship between the menstrual cycle and the ACL risk," she said. "It's very difficult because you need either continuous blood samples or saliva.

"Most of it is done predicting where in the phase women are, based on when their period starts, most studies haven't actually measured hormonal levels in the body. So it's all predictions. When you put all the data together it shows very little difference."

Dr Okholm Kryger also pointed out players often report that they are more likely to get injured when they are on their period at the start of their cycle, but actually the risk should be higher during ovulation.

3. Gender disparities

A 2021 study published in the British Journal of Sports Medicine, external suggested looking at the influence of gender - pointing at external factors such as access to training, sport science, facilities and rehabilitation.

Female footballers are likely to have significantly lower training ages - the amount of time and exposure an athlete has had to structured, coached and progressive training - compared to their male counterparts.

Other gender disparities highlighted by Dr Okholm Kryger include the pitches used in the WSL compared to the Premier League and the design of football kit such as boots. Women move and run in a different way to men and yet the length of studs on boots are designed around male movement and traction, she pointed out, which increases the risk of women getting their boot stuck in the surface and an injury being caused.

4. Workload

As women's football grows rapidly, the amount of games and the level of intensity is also growing quickly, which is leading to increasing concern among managers and players in the game.

"Obviously you can do everything to put the players in the best condition possible but with the volume of games and the limited recovery time at the moment, it's difficult to do anything about it," said Dr Okholm Kryger.

Northern Ireland striker Simone Magill had waited her whole career for 7 July, when her country made their debut at a major tournament at Euro 2022.

But 79 minutes into her side's first game against Norway, the dream was cut short.

"I went to stick my leg out to balance, and as soon as I stuck my leg out, I literally felt the ligament pull away from my leg so I knew straight away it wasn't great.

"It was horrendous. I was a mess."

Magill, 28, was helped by being surrounded by eight international team-mates who had gone through it before her.

"They were brilliant in of reassuring me. They were all examples to me that they had had it, gone through it and come back.

"I had no idea the things you have to go through. I heard about so many people doing [their ACL] but I didn't actually know what that involved."

What makes the injury so difficult is the longevity, she said, as well as having to learn the mechanics of walking again.

"I completely forgot the natural way you would walk. I was having to learn that in the house, standing in front of a mirror and just focus on doing knee to toe, I had no idea that would happen!

"I just assumed I would get surgery, be sore for a week or two, and then it would all come back to me.

"It was the mental side of all that. I kept thinking, it's not my knee, it doesn't feel like my knee. Will it ever feel like my knee again">