Why Are Female Athletes More Likely to Tear Their ACL?

It has been a little while since we last looked at ACL injuries here on RDP Reports. In a previous article, we discussed what the ACL is, how these injuries occur, and the long road athletes face during recovery. But one question continues to come up in sports medicine and among fans alike: Why are female athletes so much more likely to tear their ACL?

If you've watched women's basketball, soccer, or volleyball over the past few years, you've probably noticed a troubling trend. Some of the biggest stars in sports, including JuJu Watkins and Paige Bueckers, have suffered ACL tears that changed the course of their seasons. These injuries often happen in a split second and can keep athletes out of competition for nine months or longer.

(ESPN)

In this article, we'll take a closer look at why female athletes face a higher risk of ACL injuries. We'll explore the anatomy, movement mechanics, and muscle control that contribute to these injuries, discuss what researchers have discovered over the past several decades, and most importantly, explain what athletes can do to help reduce their risk.

What Is the ACL?

Before we can understand why female athletes tear their ACL more often, we first need to revisit what the ACL actually does.

The anterior cruciate ligament, better known as the ACL, is one of the four major ligaments that stabilize the knee. It connects the femur, or thigh bone, to the tibia, or shin bone, and acts like one of the knee's main support systems. Every time you run, jump, cut, or change direction, your ACL helps keep your knee stable.

This is why ACL injuries are so common in sports like basketball, soccer, volleyball, lacrosse, and football. These sports require athletes to constantly stop, pivot, and explode in a new direction, putting a tremendous amount of stress on the knee.

When the ACL tears, athletes often hear or feel a "pop," followed by immediate pain, swelling, and instability. Most complete ACL tears require reconstructive surgery, and returning to sport usually takes nine to twelve months of rehabilitation.

(Cleveland Clinic)

So Why Are Female Athletes at Greater Risk?

Researchers have been trying to answer this question for decades, and the answer isn't as simple as one single cause.

Instead, several factors work together to increase the risk. Some of these, like anatomy, are things athletes are born with. Others, like strength and movement mechanics, can be improved through proper training. Let's start with the factors athletes can't control.

Anatomy

One of the first differences researchers noticed was anatomy.

On average, females have a wider pelvis than males. This creates a larger angle between the hips and knees called the Q-angle. While having a larger Q-angle doesn't automatically mean someone will tear their ACL, it can slightly change how forces travel through the knee during running, jumping, and cutting.

Researchers have also found that many women have a narrower space inside the knee where the ACL sits. Some studies suggest this may place the ligament at a greater risk of injury, although anatomy alone is not enough to explain why ACL tears happen more often in females.¹

The important thing to remember is that plenty of female athletes with these anatomical differences never tear their ACL, while many male athletes still do. Anatomy is only one piece of the puzzle.

(Runners Connect)

The Way We Move

If you've ever watched an athlete tear their ACL, you've probably noticed something surprising. Most of the time, nobody touched them.

Many ACL injuries happen when an athlete lands from a jump or plants their foot to quickly change direction.

Researchers have found that female athletes are more likely to land with their knees collapsing inward. This movement has a complicated name, dynamic knee valgus, but it simply means the knees cave toward each other instead of staying lined up over the feet.

Think about jumping off a small box. If your knees stay over your toes and your hips bend as you land, your muscles absorb most of the force. But if your knees cave inward and your legs stay stiff, much more of that force is placed directly on the ACL.

Over time, these movement patterns can increase the risk of injury, especially during fast-paced sports where athletes jump and change direction hundreds of times throughout a season.²

The good news is that movement mechanics can be improved. Unlike anatomy, this is something athletes can train.

Strength Matters More Than You Might Think

Strong muscles don't just make athletes faster or more powerful. They also help protect the knee.

The hamstrings are especially important because they help stabilize the knee and take some of the pressure off the ACL. The glutes also play a major role by keeping the hips and knees properly aligned during jumping, landing, and cutting.

Researchers have found that female athletes often rely more on their quadriceps during these movements while using their hamstrings less effectively. This can place additional stress on the ACL. Weak glutes can make the problem even worse by allowing the knees to collapse inward during landing.¹

This is why many ACL prevention programs spend so much time strengthening the hamstrings, glutes, and core. Stronger muscles help the body move more efficiently and reduce unnecessary stress on the knee.

(SimpliFaster)

What About Hormones?

You've probably heard people say hormones are the reason female athletes tear their ACL more often. While hormones may play a role, the answer isn't quite that simple.

Researchers have studied hormones like estrogen because they may affect how flexible or loose the ACL becomes during different phases of the menstrual cycle. Some studies have found a possible connection, while others have found little or no relationship at all.³

Right now, most experts agree that hormones are probably only one part of the story. They may slightly increase the risk, but they don't fully explain why female athletes experience more ACL injuries than males.

Instead, it's likely that anatomy, movement mechanics, muscle strength, and hormones all work together to influence an athlete's overall risk.

Final Takeaway

Learning that female athletes have a higher risk of tearing their ACL can sound discouraging, but it shouldn't be. The most important takeaway from years of research is that many of these injuries are not simply a matter of bad luck. While factors like anatomy can't be changed, many of the biggest risk factors, including strength, movement mechanics, and neuromuscular control, can all be improved through proper training.

For athletes, this means that injury prevention should become just as important as strength training or practicing sport-specific skills. Learning how to land properly, strengthening the glutes and hamstrings, improving balance, and completing an evidence-based warm-up before practices and games can all help reduce the risk of an ACL injury. These small habits may not seem significant on any given day, but over the course of a season they can make a meaningful difference.

As sports medicine continues to evolve, the goal is no longer just helping athletes recover from ACL tears. It's preventing them from happening in the first place. By understanding the science behind these injuries and taking prevention seriously, athletes can spend less time in rehabilitation and more time competing in the sports they love.

References

1. Hewett TE, Myer GD, Ford KR. Anterior Cruciate Ligament Injuries in Female Athletes: Part 1, Mechanisms and Risk Factors. American Journal of Sports Medicine. 2006;34(2):299-311. doi:10.1177/0363546505284183

2. Griffin LY, Agel J, Albohm MJ, et al. Noncontact Anterior Cruciate Ligament Injuries: Risk Factors and Prevention Strategies. Journal of the American Academy of Orthopaedic Surgeons. 2000;8(3):141-150. doi:10.5435/00124635-200005000-00001

3. Arendt EA, Dick RW. Knee Injury Patterns Among Men and Women in Collegiate Basketball and Soccer.American Journal of Sports Medicine. 1995;23(6):694-701. doi:10.1177/036354659502300611

4. Sugimoto D, Myer GD, Bush HM, Klugman MF, Medina McKeon JM, Hewett TE. Compliance With Neuromuscular Training and Anterior Cruciate Ligament Injury Risk Reduction in Female Athletes: A Systematic Review and Meta-analysis. Journal of Athletic Training. 2012;47(6):714-723. doi:10.4085/1062-6050-47.6.10

5. American Academy of Orthopaedic Surgeons. Management of Anterior Cruciate Ligament Injuries Clinical Practice Guideline. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2022.

6. Fédération Internationale de Football Association (FIFA). FIFA 11+: Complete Warm-Up Programme. FIFA Medical Network