According to the American Academy of Orthopedic Surgeons (AAOS), anterior cruciate ligament (ACL) injuries, usually related to sports, have an incidence of approximately 252,000 annually, with women two to eight times more likely to have an ACL injury vs. men.
ORA Orthopedics Sports Medicine Surgeon, Dr. Ryan Dunlay, says his practice reflects this national trend. “Yes, we do tend to see a prevalence of ACL injuries among young women athletes compared to their male counterparts, especially in soccer, gymnastics, and girls basketball.” Why?
The ACL is a knee ligament that crosses with the posterior cruciate ligament (PCL) in the middle of the knee. While the PCL is primarily involved in stopping or starting motions, the ACL is enables athletes to pivot, jump, and turn quickly.
“The latest research reveals that the major cause for non-contact ACL injuries is the difference in neuromuscular knee motion between female and male athletes during athletic maneuvers,” explains Dr. Dunlay.
“It’s not the anatomical alignment of the female hip as once thought. We don’t think that the shape of the hip or angle of hip/knee contributes to the increase in ACL injuries. Instead, it’s a muscular control issue.
“Researchers think young women use their quadriceps muscles more than their hamstrings, so when they jump, they have less flexion when they land, compared to males. ACL injuries happen in non-contact situations when there is a hyperextension of the knee in what we call a ‘valgus’ or ‘knock kneed’ motion. Girls, in particular, are more at risk because they land with less flexion and more of a turned knee.”
Because ACL injuries are more likely to result in reconstructive surgery and lengthy rehabilitation and physical therapy, understanding the cause can point the way to prevention.
Dr. Dunlay says there are encouraging neuromuscular programs that retrain young athletes to land correctly, thereby helping to prevent ACL injuries from occurring. “If coaches, parents, and athletes are aware that retraining programs are available to avoid knock-kneed landings, studies are showing a significant reduction in injuries if the athletes stick to the program.”