Why Are ACL Tears So Common in Girls? Understanding the Risks and Prevention Strategies

Anterior cruciate ligament (ACL) tears are among the most feared injuries in sports, known for their lengthy recovery times and potential long-term effects on athletes' careers.  In this blog, we’ll explore the factors contributing to the higher incidence of ACL tears in girls and discuss prevention strategies that can help protect young female athletes.

1. Anatomical Differences

One of the primary reasons girls are more prone to ACL tears is due to anatomical differences between males and females. These differences, while natural, can create biomechanical challenges that increase the risk of injury.

• Wider Pelvis: Girls generally have a wider pelvis than boys, which affects the alignment of the legs. This can lead to a greater angle at the knee, known as the Q-angle, which increases stress on the ACL during activities that involve cutting, pivoting, or jumping.

• Narrower Intercondylar Notch: The intercondylar notch is a groove in the femur through which the ACL passes. In females, this notch tends to be narrower, which can make the ligament more susceptible to injury during high-stress movements.

• Joint Laxity: Girls often have greater joint laxity, or looseness, which can lead to less stable joints. While flexibility is generally a good thing, excessive joint laxity can increase the risk of the knee joint moving beyond its safe range of motion, leading to ACL tears.

2. Hormonal Factors

Hormones also play a significant role in the higher rate of ACL injuries among girls. The hormone estrogen, which is present in higher levels in females, can affect ligament strength and the way muscles function.

• Estrogen and Ligament Strength: Research suggests that estrogen may reduce the strength and stiffness of ligaments, including the ACL. This makes the ligament more prone to stretching or tearing, especially during the phases of the menstrual cycle when estrogen levels are higher.

• Menstrual Cycle Influence: Some studies have found that ACL injuries are more likely to occur during certain phases of the menstrual cycle when hormone levels fluctuate. These hormonal changes can impact muscle control and joint stability, increasing the risk of injury.

3. Neuromuscular Differences

Neuromuscular factors, which involve the coordination and control of muscles and joints, are also crucial in understanding why ACL tears are more common in girls.

• Muscle Activation Patterns: Girls and boys tend to use different muscle activation patterns during physical activity. Girls are more likely to rely on their quadriceps muscles (the muscles at the front of the thigh) rather than their hamstrings (the muscles at the back of the thigh) when performing movements like jumping and landing. This imbalance can put more stress on the ACL.

• Landing Mechanics: Girls often land with their knees more straight and inwardly rotated, a position that increases strain on the ACL. This poor landing technique is a significant risk factor for ACL injuries.

• Balance and Coordination: Differences in neuromuscular control can also affect balance and coordination. Girls may have less efficient neuromuscular control during dynamic movements, which can lead to improper knee alignment and increased risk of injury.

4. Sports Participation and Training Factors

The types of sports girls often participate in, as well as their training practices, can also contribute to the higher incidence of ACL tears.

• High-Risk Sports: Girls are increasingly participating in sports like soccer, basketball, and volleyball, which involve a lot of cutting, pivoting, and jumping—movements that put a significant strain on the ACL.

• Inadequate Training: Many young female athletes do not receive proper training in techniques that can reduce ACL injury risk. For example, learning how to jump and land properly, strengthening the hamstrings, and improving overall neuromuscular control can all help protect the ACL.

• Early Specialization: Some girls specialize in a single sport at a young age, leading to repetitive stress on the same joints and muscles. This lack of varied physical activity can contribute to overuse injuries, including ACL tears.

5. Prevention Strategies

While the risk of ACL tears cannot be entirely eliminated, there are several effective strategies that can help reduce the incidence of these injuries in girls.

• Neuromuscular Training Programs: Structured programs that focus on improving strength, balance, and coordination can help reduce the risk of ACL injuries. These programs often include exercises that emphasize proper landing mechanics, knee alignment, and muscle activation patterns.

• Strengthening Exercises: Strengthening the muscles around the knee, particularly the hamstrings, can help protect the ACL. Strong hamstrings can counterbalance the force exerted by the quadriceps, reducing the strain on the ACL during high-risk movements.

• Flexibility and Mobility Training: While joint laxity can be a risk factor, maintaining appropriate flexibility and mobility in the hips, knees, and ankles is important. Balanced flexibility training can help ensure that joints move through their natural range of motion without excessive strain.

• Proper Technique Training: Educating young female athletes on proper techniques for jumping, landing, cutting, and pivoting can significantly reduce the risk of ACL injuries. Coaches and trainers should emphasize these techniques during practices and games.

• Awareness of Menstrual Cycle: For older female athletes, being aware of the phases of their menstrual cycle and how it might affect their risk of injury can be beneficial. Some athletes may choose to adjust their training intensity or focus on injury prevention exercises during higher-risk times.

Conclusion

ACL tears are a significant concern for female athletes, with a variety of factors contributing to their higher risk. Anatomical differences, hormonal influences, neuromuscular control, and sports participation all play a role in making girls more susceptible to these injuries. However, with proper training, awareness, and preventive measures, the risk of ACL tears can be reduced. By focusing on strength, technique, and neuromuscular control, young female athletes can protect their knees and continue to participate in the sports they love with confidence and safety.

At Princeton Sports and Family Medicine, P.C., our doctors specialize in sports medicine services, including exercise counseling and physician services to assess your risk for injury and assist in your performance goals.

Call or click to book a session with our professionals at Princeton Sports and Family Medicine, P.C. In addition to problem-focused visits, we offer sports performance evaluations to stop problems before they start. Plan your visit today!

Author

Peter Wenger, MD Peter C. Wenger, MD, is an orthopedic and non-operative sports injury specialist at Princeton Sports and Family Medicine, P.C., in Lawrenceville, New Jersey. He is board certified in both family medicine and sports medicine. Dr. Wenger brings a unique approach to sports medicine care with his comprehensive understanding of family medicine, sports medicine, and surgery. As a multisport athlete himself, he understands a patient’s desire to safely return to their sport.