New research indicates that women are more likely than men to suffer an ACL tear.
ACL tears occur when the anterior cruciate ligament — one of the most crucial ligaments in promoting stability of the knee — ruptures, usually after a sudden change in force or direction. For this reason, they’re particularly common in professional athletes, but ACL tears can, and do, happen to anyone.
While the causes of ACL tears are well-documented, a recent study published in The American Journal of Sports Medicine has provided even more insight into them. By using multivariate analysis to identify common risk factors, the researchers found that men and women are more likely to tear an ACL if certain conditions are present. Confirming previous research, which has long shown that women are more likely to suffer an ACL injury than men, the study advances these findings by revealing some key reasons for these differences.
The Importance of Loose Ligaments
Prior studies of ACL tears reveal that women are more susceptible to them because they land quite differently from men. Women, for example, land with greater extension in their knees, and their knees often land in valgus, an outward angling of the leg, because their hips tend to internally rotate. These risks can be minimized with proper conditioning, correct landing techniques, and neuromuscular training, but they can’t be entirely eliminated.
The Journal’s study identified some additional contributors to ACL tears in men and women alike. It concludes that stiffness in the back of the knee, navicular drop, and decreased standing angles in the quadriceps all increase a man’s risk of tearing an ACL, suggesting that structural defects are a major contributor to ACL tears in men. In contrast, a family history of ACL tears, particularly in one’s parents, and a higher body mass index raise a woman’s risk of an ACL tear. It’s unclear why women seem to suffer from a hereditary predisposition to this injury, but future research may clarify this question.
While the Journal of Sports Medicine’s study suggests that risk factors vary for men and women, it does indicate that both sexes share one major risk factor: increased anterior-posterior laxity of the knees. What this means is that people with looser ligaments in both the front and backs of the knees are at greater risk of suffering an ACL injury. While loose ligaments aren’t necessarily abnormal, they can be a cause for concern if they are the result of previous injuries. Fortunately, loose ACL ligaments can be treated with a specialized exercise regimen and physical therapy designed to stabilize the knee.