With the 40th anniversary of Title IX upon us, our nation has seen huge advancements in striving for equality for women in the realm of sports and athletics. With this increase in sports participation, however, we have seen an increase in sports-related injuries in female athletes.
Specifically, in the last decade research has shown that females are now 8-10 times more likely to sustain an ACL tear compared to males playing similar sports. There are many factors that contribute to this gender-based discrepancy such as differences in ACL anatomy, neuromuscular control, limb alignment and hormones.
ACL tears are no longer career-ending injuries the way they once were back a few decades ago, however, it can still take around 6-9 months to return to play even with modern reconstructive techniques. This raises many concerns for people, specifically parents of pediatric and adolescent female athletes. The main question most parents have for me as a sports surgeon is what can be done to prevent such a devastating injury from happening in the first place. If we look at all the risk factors, it becomes apparent that a lot of the risk is inherent to the athlete’s body and can’t be altered.
The ACL connects the thigh bone (femur) to the shin bone (tibia) and prevents the shin bone from moving forward and rotating underneath the tibia. It resides in an area at the end of the thigh bone called the intercondylar notch. In female athletes, the intercondylar notch tends to be narrower than in males. Further, the ACL itself tends to be narrower and thinner on average than in males. These are body characteristics unique to the genetic make-up of the individual that cannot be modified.
Extensive research has shown that there are gender-related differences in how males and females control their lower extremities when they are landing from jumps and engaging in cutting/pivoting activities. The majority of the muscles that stabilize the knee during these activities are the quadriceps and hamstring muscle groups of the thigh. Research has shown that females not only recruit different muscles during these activities, but they recruit them in a different order.
Prevention measures have focused on neuromuscular training and plyometrics as ways to decrease ACL injuries. There are equal data that disagree about the effectiveness of these measures. Higher quality, long-term studies need to be performed before definitive recommendations can be made about formally recommending neuromuscular training.
Females tend to be more knock-kneed and have forward-rotated thigh bones compared to males. During cutting, pivoting, and landing activities, this particular limb alignment puts excessive force on the knees and makes the ACL susceptible to rupture. It is possible to correct abnormal limb alignment but it typically involves extensive surgery that is not indicated as a routine prevention measure.
Obviously, there are extensive hormonal differences that exist between males and females. The hormone estrogen has been shown to decrease the biomechanical properties of the ACL and make it weaker. There has been research that shows females may be more susceptible to ACL injury during particular phases of the menstrual cycle. In addition, hormonal contraception has been implicated but with inconclusive data.
If you or your child is a female athlete trying to reduce your risk of ACL injury, always ensure that you are adequately warmed-up, rested, and hydrated prior to athletic participation. In addition, you can consult with a sports medicine specialist on how to enroll in a neuromuscular or plyometrics training program.
There are no guarantees that you’ll avoid an ACL injury with these preventive exercises, but there are also no risks associated with them. At the very least, you’ll increase tone and become more limber.
-Alfred Atanda, M.D.