Non-Contact ACL Injuries in Females
The Anterior Cruciate Ligament (ACL) is one of the most commonly injured ligaments in the human body, especially amongst athletes. But did you know that females are at an increased risk for ACL injuries? But why is that? And hey, what exactly is the ACL anyways? Where is it located and what does it do? And what can female athletes (and other athletes) do to help reduce their risk of ACL injuries? I will talk about these things and answer those questions in this blog post!
What is the ACL?
The ACL is one of the key ligaments that help to stabilize the knee joint. It connects the femur to the tibia and helps to stabilize the knee during rotation. It also helps to prevent the tibia from moving too far forward in relation to the femur during sudden stops, twists, and when landing or jumping. But this ligament, just like any other structure of the body, can only take so much stress before it gives out.
Mechanics of ACL Injuries
According to The American Orthopedic Society for Sports Medicine, about 150,000 ACL injuries occur every year in the US. Out of these, only 30% are due to contact (like a football tackle or car accident) and recent studies reveal that young female athletes are 4 to 6 times more likely to suffer a serious non-contact ACL injury than males. And while there’s some debate as to why this is the case, there are some factors that singularly, or in combination with each other, greatly increase the risk of ACL injuries in females.
Intercondylar Notches And Parking Spaces
One reason why females are at greater risk for non-contact ACL injuries is that they tend to have a more narrow intercondylar notch. The intercondylar notch is the groove in the femur through which the ACL passes. It tends to be smaller and more narrow in women, which makes an ACL injury more likely to occur. Think of it like trying to park a car: the more narrow the parking space is, the more likely it is that you’re going to accidentally scrape the side of your car along with the neighboring car. In this case, your ACL is the car being parked, and the intercondylar notch is represented by the neighboring cars that are determining the size of the parking space. The smaller the parking space (or, the more narrow the intercondylar notch is) the more likely it is that an undesired outcome will occur.
Q-Angles And ACL Injuries
Another risk factor for non-contact ACL injuries in females is that they tend to have a wider pelvis than men. This causes the bottom of the femur to go in toward the midline of the body at more of a steep angle. This angular relation of the pelvic, femur and knee is referred to as the Q-Angle. The increased Q-Angle in females means that they’re more likely to push their knees toward each other during movements, especially when squatting or landing from a jump. And when that inward knee movement occurs, it greatly increases the risk of the ACL being injured.
This is also one of the reasons why it’s important that athletes (all athletes, not just female) land on the balls of their feet instead of flat-footed when jumping. When landing flat-footed, it doesn’t allow the force of the impact to be absorbed in the feet and calves, which leaves the knees in a more vulnerable position for injury.
Reduce The Risk of Non-Contact ACL Injuries
There are a few specific ways that females can reduce the risk of an ACL injury with training. Some of those include: proper and equalized strength training of the legs and hips (specifically, the lateral hip muscles), proper neuromuscular (balance and speed) training and training on proper jumping and landing techniques. Many of these require the supervision of a exercise specialist, but here’s a video of an exercise that female athletes (or any athlete) can do at home to help strengthen the lateral hip muscles, which are critical in protecting your ACL’s during athletic activities:
And remember: while being physically active and involved in sports is beneficial in many ways for people of all ages, training with proper form and function is critical in reducing your risk of injury. Moving, in general, is good, but moving correctly is key to injury prevention. I would recommend participating in a FMS screen test in order to learn more about how your body moves, and the ways you can improve your movement patterns in order to reduce your risk of injury.