ACL injuries plague women's soccer
04:01 - Source: CNN
CNN  — 

You know it the moment it happens. Sometimes it comes with an audible pop. Other times it’s just enough pain to signal that something isn’t quite right.

When you tear your anterior cruciate ligament or ACL, it’s less about the pain in the moment, but more about the pain of knowing that surgery and a year-long recovery lie ahead.

I know this because I’ve torn mine twice. Both times, the same knee. Both times, playing soccer.

After seeing the headlines of how many of the world’s top players are missing out on this year’s Women’s World Cup — including two from the US team — it’s hard not to think of this injury as an inevitable part of the sport, especially as a woman.

Different studies have found female athletes are two to eight times more likely than their male counterparts to tear their ACLs.

“This issue has been around for a long time, it’s gotten worse and worse,” says Dr. Andrew Pearle, chief of sports medicine at the Hospital for Special Surgery in New York City.

But then why haven’t we done anything about it?

It may be too late for me or the countless others who have already suffered from this injury, but there are things that can and should be done starting with even our youngest players.

Ahead of the Women’s World Cup, CNN Chief Medical Correspondent Dr. Sanjay Gupta and I spoke to trainers, physical therapists and doctors, and it’s clear that there are ways to prevent this, starting with even the youngest players.

Many of these things, I really wish I had known.

Why women?

The people we spoke to say there are many risk factors that can play into injuries, including the level of resources going to players, possibly the type of field, specializing too early in one sport; maybe it’s anatomy or biomechanics.

When it comes to women, I had always heard that we were more likely to tear their ACLs because of their wide hips, but Holly Silvers-Granelli, chair of Major League Soccer’s medical assessment research committee, says it’s more than that.

“When we started looking at this data, literally 23 years ago, back in 2000, we had determined that there’s anatomic risk factors, there’s hormonal risk factors, there’s environmental risk factors,” says Silvers-Granelli, who has a masters in physical therapy.

Let’s start with a quick ACL primer. The ACL is a ligament that runs diagonally from the outside of your femur to the inside of your tibia. “If you slide your hands into your pockets, that’s the direction the ACL runs,” explains Silvers-Granelli.

This ligament is what helps people move laterally, but women’s ACLs tend to be smaller.

The Q angle is the ratio of hip width to femur length; women have larger Q angles, which can put more stress on the ACL.

Women also have larger Q angles — the ratio of hip width to femur length. This matters because this angle can cause someone to more easily go into a knocked-knee position and that puts more stress on the ACL.

Think of that position like Elvis’ famous dance, says Pearle. “That’s how people pop their ACL. Their knees come together. Twenty-five years ago, when they first discovered it, they were watching films, they’re like, oh, they look like Elvis, because their knees come together, but we call it dynamic valgus.”

Elvis Presley, rock and roll star of the 1950's performing on stage.

These are the risk factors we can’t control, but the good news is, the ones we can control can make a big difference.

Injuries aren’t inevitable

On April 19, Leah Williamson, captain of the England national team, was playing for her club, Arsenal, against Manchester United. As she stepped to intercept the ball, she went down right away.

Silvers-Granelli says she could tell almost immediately what had happened.

“Her foot is outstretched. She’s basically, there’s zero bend to her knee and hip. Her hip is to the side, we call that hip abduction and then she inwardly rotates. It’s a classic mechanism.”

Williamson tore her ACL just three months ahead of the World Cup.