Timothy Hewett, PhD, FACSM; Director of Research, The Ohio State University Sports Health and Performance Institute. Dr. Hewitt specializes in researching ways to prevent ACL injuries in young women.
100,000 – 250,000 ACL injuries occur each year in the U.S. Females are between 2 and 10 times more likely to tear their ACL than men, especially women participating in high-risk landing/cutting/jumping activities. The ACL is a sensor full of mechano-receptors and the tissue senses the positioning of the knee joint in three-dimensional space. Once the ACL is torn, this sensor does not work properly. Deficient neuromuscular control may contribute to ACL injury risk. Following an ACL tear, the ability to generate power is significantly reduced. The female athletes have a lot more force, with less power to control that force. Women have significantly less ability to balance on a single limb after ACL tear/surgery than men in a similar situation.
Once you tear one ACL, your risk of tearing another ACL is much more likely. Neuromuscular repair is limited once an ACL tear occurs. When athletes return to sports, post-ACL reconstruction, their landing force profiles are abnormal. Force on non-operated limb is reduced. 23% (1 in 4) women will tear a second ACL. Five times higher risk in women than in men for a second ACL tear.
Those with a second ACL injury had an internal hip turn when jumping and landing. A neuromuscular control loss will cause the non-injured side of your body to drop to equalize.
Coupled biomechanical studies identify risk of ACL tears in women. We need to evaluate a greater number of athletes to get more data. After evaluation, athletes go out and play as usual and follow-up is done with athletes if they at some point tear their ACL.
Physical therapy is changing to try and address potential issues in advance. Move toward technique progression, stability progression, single leg lateral progression, symmetry side to side, single leg rotator progression and lateral trunk progressions are being done with athletes in this study. The goal is to get athletes back to their sport, while also evaluating their movements.
ACL injuries are genetically based. Filing information in web portals is helping keep data in one place. “Understanding and Preventing ACL Injuries” is a great resource for additional information about preventing ACL injuries.
Would this screening ever be incorporated into school physicals?
Yes. We are hoping to get these studies incorporated into PPEs (already being done). Encourage your local study reviewer to support the grant to help get this incorporated into pre-sports physicals.