Female athletes are at a greater risk of tearing their ACL, yet most of the research focuses on men.
The anterior cruciate ligament (ACL) is the most crucial ligament in stabilizing your knee joint. It is a band of tissue that holds together the femur (thigh bone) and tibia (shinbone). The ACL provides control for rotation in the knee and prevents the tibia from moving in front of the femur. By ensuring that your knee is in proper alignment, the ACL is essential for peak physical performance and helps prevent injuries to the knee during physical activity. The ACL is vital in performance sports and the average day to day functions for everyone, non-athletes and athletes alike.
As is the case with every other part of the human body, the ACL is susceptible to injury. There are three types of ACL injuries. First, there is a grade 1 sprain, where the ACL is slightly stretched and damaged but it is still intact and working. Then there is a grade 2 sprain, which is considered a partial tear of the ACL. In a grade 2 sprain, the ligament is loose.
The final type of injury is a grade 3 sprain, also known as an ACL tear. As the name implies, a grade 3 sprain occurs when the ligament is fully torn in half or pulled off the bone and the kneecap is unstable. ACL injuries are most common in sports such as soccer, basketball and football. They can happen for a number of reasons such as slowing down too fast, moving in a different direction too suddenly, landing from a jump wrong or even a direct collision.
While ACL injuries can happen to anyone, there's evidence that female athletes are more affected than male athletes. Female basketball players are three-and-a-half times more likely to tear their ACL than their male counterparts. Additionally, female soccer players are 2.8 times more likely to tear their ACL than male soccer players. Overall, women are two to eight times more likely to tear their ACL, but it's difficult to pinpoint exactly what is the root cause.
When it comes to ACL injuries, it is rarely as simple as one cause injury. One way to think of ACL injuries is as a mixture of events creating a stars aligning moment. Hormones, biomechanics and anatomy are thought of three main reasons as to why women have a more difficult time with injuries.
It has been found that the ACL has cells in it that respond to female hormones such as estrogen and progesterone. The cells have a docking station where hormones like estrogen can attach and affect the way the cells behave. The estrogen slows how quickly the cells can grow and make collagen. Collagen is a protein that acts like the "glue" for ligaments, which allows them to stay strong and flexible. Since estrogen can fluctuate depending on the stage of the menstrual cycle, the cycle can influence a woman's susceptibility to an ACL injury.
The biomechanics of male and female athletes are different. When landing from a jump, women tend to land in a more upright posture. This means their knees aren't as bent as those of male athletes. Men also land with more core engagement than women do. This difference in landing styles shows how women's ACLs are put under more stress, which can eventually lead to an injury.
When it comes to anatomy, women generally have wider hips, and their knees tend to tilt more inward. Because of this knee alignment, the risk of injuring the ACL during physical activity is greater for women than it is for men. The ACL tissue in a woman's knees is also typically thinner than in a man's knees, which makes them more susceptible to a tear.
For these reasons, ACL injuries have plagued women's sports. Soccer stars like Tierna Davidson, Sam Kerr and Mia Fishel have injured their ACLs in recent years. There have been even more injuries in women's basketball; some notable instances are Georgia Amoore, Cameron Brink and Juju Watkins. The Seattle Storm have three players out for the season due to ACL tears: Katie Lou Samuelson, Jordan Horston and Nika Mühl. Recently, Kansas City Current player Alana Cook tore her ACL.
Despite the fact that ACL injuries disproportionately affect women, most of the current research is done on men. As outlined earlier, women and men have different physiques as their bodies react to things differently. Research needs to take that into account, especially when it comes to ACL injuries. This lack of research plays a part in the fact that men generally have better recovery than women do.
Even after recovery, women were 33.7 percent more likely to need surgery on their other knee after an ACL injury, which is something that we have seen in the past with athletes like Megan Rapinoe, Anna Heilferty and Bria Hartley. In contrast, men's knees were more stable, their legs were more evenly strong and they scored better on recovery tests. Women are also more likely to need another surgery done on the same knee (revision surgery).
Researchers also need to take into account that coming back from a serious injury isn't just a physical feat -- it's psychologically challenging. Psychologists have known for a long time that women, on average, have less confidence than men. This makes coming back from an injury especially more difficult for a female athlete. This is backed up by a study showing that women had lower confidence going into ACL surgery compared to men.
Women are also generally more anxious in life. This affects how they recover from an injury. Since they are more nervous to return after an ACL injury, it is harder for them to return to playing sports. In fact, research from 18 studies has shown that women are less likely than men to get back to the same level of sport they were at before their injury.
Fortunately, research has come a long way when it comes to treating ACL injuries. This predicament used to be thought of as career-ending injuries in cases like Derrick Rose's. Rose was the youngest MVP in the NBA and a generational talent before he tore his left ACL in 2012. Unfortunately, he was never able to fully regain his peak athleticism following the devastating injury.
ACL injuries today don't bring the same impending death of one's career like they used to. Athletes such as University of Connecticut basketball star Azzi Fudd have been able to bounce back stronger. Fudd tore her ACL as a junior in 2024, but has since made a full recovery and played an instrumental part in their 2025 March Madness championship run.