ACL

Anterior cruciate ligament (ACL) injuries are a significant concern for female athletes, particularly in sports requiring rapid cutting, pivoting and landing, such as soccer, gymnastics, rugby and lacrosse. There has been a notable increase in these injuries over the last few decades, especially among children and adolescents.

Data reveal a clear sex disparity; compared to male athletes, females are two to eight times more likely to suffer an ACL tear. While this sex disparity tends to lessen with age and at the professional level, risk factors are multifactorial, involving potential anatomical, hormonal and biomechanical differences between males and females.

Fortunately, ACL injury risk can be significantly reduced through neuromuscular training programs that focus on improving strength, balance and proper movement mechanics.

What is the ACL?

The anterior cruciate ligament (ACL) is a ligament (a type of tissue that connects two bones) that plays a crucial role in keeping our knees stable during sports and in daily life.

It runs diagonally through the center of the knee, connecting the femur (thigh bone) to the tibia (shin bone). Its primary function is to maintain knee stability by preventing excessive forward movement and rotation of the tibia relative to the femur. This stabilization role makes the ACL especially important during dynamic, high-intensity activities that require twisting, pivoting and landing movements.

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How do ACL Injuries Occur?

An ACL injury occurs when the ligament is stretched beyond its capacity– resulting in a sprain or a tear– typically during sports involving rapid deceleration and direction changes.

Injuries frequently stem from non-contact movements like cutting, pivoting or landing after a jump, but they can also result from direct contact like a tackle or collision.^1,2 When the ligament is torn, athletes may hear or feel a “pop,” experience immediate pain and swelling at the knee and/or have a feeling of instability with activities.

More than 200,000 ACL tears are predicted to occur annually in the United States, more frequently in adolescent and young adult athletes.³ One meta-analysis assessing ACL injuries of adolescents estimated that female athletes engaging in multiple sports have nearly a 10% risk of ACL injury over their high school careers.⁴ This meta-analysis also found that, in female athletes, ACL injuries are more than eight times more common during competition versus standard practice.⁴

ACL tears are typically treated with surgical reconstruction, but the recovery can be lengthy and there is an elevated risk of re-injury with returning to sport too soon.⁵ Thus, focusing on injury prevention through athletic training is important.

Why Female Athletes Are at Higher Risk

Research consistently finds that female athletes experience ACL injuries up to two to eight times more frequently than male athletes and the general population.^4,6

Despite prevention efforts, the incidence of these injuries continues to rise, especially among youth and adolescent athletes.^{4, 7-9}

As mentioned above, the risk of ACL injuries in female athletes is highest during adolescence (age 12-16), though this disparity tends to narrow as athletes mature, with ACL injury rates becoming more comparable between male and female athletes competing at the professional level.^{1, 9}

The reasons for elevated risk of ACL injury in females are multifactorial and research in this field is expanding to uncover more information on the topic. It is important to note that study methodologies and terminology are inconsistent and often lack important information (e.g., menstrual cycle phases may not be clearly defined, hormonal measurements are not performed), so it is important to be cautious when interpreting research outcomes.

Injury Prevention

Research has shown that neuromuscular training programs can successfully reduce the risk of ACL injuries in female athletes by up to nearly 50%.^15-18

Treatment and Long-Term Outcomes of ACL Injury

For athletes wishing to return to sports that involve cutting and pivoting movements, surgical reconstruction of the ACL is often recommended.⁶

After adhering to proper rehabilitation with benchmarks for progression, athletes can achieve a successful return to their sport following surgery.^20-22 Alternatively, some ACL tears can be managed conservatively with bracing and physical therapy, without surgery. Regardless, physical therapy is an essential component of rehabilitation, helping to restore strength and agility and supporting a safe return to activity.

Despite successful surgical reconstruction, female athletes face a continued risk of re-tearing the ACL on either the same side (ipsilateral) or the opposite side (contralateral) of the knee.^23-26 Beyond re-injury, ACL tears are also associated with significant long-term sequelae, including an increased risk of early-onset knee osteoarthritis and various psychological impacts like a heightened fear of re-injury and depression.^{6, 26}