There is no definitive answer as to why women are up to eight times more likely to suffer an ACL injury than men. The reasons are often multifaceted and based on the differences between male and female anatomy, but there is a growing body of evidence that the “biological” argument often associated with ACL injury may be misrepresenting an underlying cause.
A 2020 study in the British Medical Journal for Sport and Exercise Science, published in the wake of an alarming rise in ACL injuries in Australian football, suggested that when equal opportunity in age training exists, the disparity in ACL injury rates and greatly reduce, or even disappear, risk factors between female and male athletes.
“There is fairly compelling evidence that if you train girls and women to the same extent as boys and men, their risk of injury goes away,” said Dr. Georgina Stebbings, a lecturer in sports and exercise physiology at Manchester Metropolitan University. “It shows that men’s sports and boys’ sports are much better supported, in the longer term, while women are chronically underfunded and supported.”
Genetics have also been found to play a role: Peer-reviewed research published this year in the Sports Medicine Journal found that having a family history of ACL injury is more than double the chance of getting one. . However, differences in male and female anatomy are the oft-cited factor. Women’s knees, for example, have smaller ligaments, making them more prone to injury.
“When you look at women landing from a jump, especially if they’re not properly trained, their knees sink in,” says Dr. Stebbings. “It’s in that inward collapse position where the ACL works really hard to make sure they don’t collapse. Men have narrow hips because they don’t have to accommodate a growing baby, so they don’t have that inward collapsing knee.”
Therefore, range of motion is considered one of the most important strategies to prevent ACL injuries. When Gilbert finished training at an elite women’s soccer club in the United States in 2011, he was surprised by how many ACLs were on everyone’s radar.
“Football players in America were almost everywhere women because men played football, baseball, and ice hockey,” he says.
“Parents were really concerned if their daughter had an ACL tear, because playing football in college would mean a scholarship, meaning a university education was massively discounted. So many high schools have ACL prevention programs aimed at women and girls, knowing they have a higher risk of ACL tear.
“You would hope that over time this would trickle down to amateur clubs or schools in England. There are certain things you should do to strengthen girls’ knees to avoid the risk of ACL tears. They look at the strength of girls, how they jump and land, because all that stuff is really important to reduce that risk.”
‘We need to understand that women are not short men’
It was 2014 when the Football Association rolled out its first injury prevention pilot program in youth football. More than 600 girls in the FA’s now-disbanded Advanced Coaching Centers received physical activity training, some for eight years. Coupled with a commitment to upskilling coaches, the initiative resulted in an estimated 1,800 girls’ injury reduction.
Gilbert points to the explosion in women’s football as one of the reasons behind the current high incident rate: 12 players from 23 clubs in England’s top two had ACL problems during the 2019-20 season.
“Suppose there was a boy who tore his ACL when he was playing for Liverpool,” he says, “he might play for a lower club and you’ll never see him again. In the women’s game they come because the play pool is smaller, probably more forward at the highest level.”
There remains a heated debate about whether a woman’s menstrual cycle is related to an ACL rupture due to fluctuations in the female sex hormone estrogen, which is thought to increase the laxity of the soft tissue structures around the knee. “All the workouts we do on women are largely based on what we know is effective in men,” says Dr. Stebbings.
“There is an assumption that if it works well for men and boys, we want similar results in women. We have to understand that women are not short men.”
The sooner that mantra is embraced, perhaps major tournaments will no longer be marred by ACL injuries from some of the game’s biggest stars.