Alex Morgan, Megan Rapinoe, Brandi Chastain, Ali Krieger, Aly Wagner, Christie Rampone, Rachel Buehler, Shannon MacMillan, Heather Mitts. What do these athletes have in common? Apart from being members of the current or former US Women’s National Teams, they have all suffered ACL injuries. In fact, many of them have suffered the injury twice. And many other current and former US players have torn their ACLs and could be added to that list.
If there is one injury that could define a specific group of athletes, it is ACL injuries in female soccer players.
Noncontact ACL injuries
Read the descriptions of their injuries. You will usually notice a similar mechanism of injury for each athlete. She might have been planting her foot to change direction, such as making a quick lateral move to evade a defender or defend an opponent. Or she might have landed awkwardly from a jump. She feels a pop in her knee, and she collapses to the ground.
Statistics on ACL injuries in female athletes
These noncontact ACL tears afflict female athletes much more frequently than men. A 13-year study of ACL injuries in NCAA men’s and women’s soccer found that the rate of ACL tears for female soccer players is about three times higher than it is for males. Studies of other ages and sports show similar trends. Females athletes have anywhere from 2 to 8 times the risk of tearing their ACLs in sports.
Risk factors for ACL injuries in female athletes
Many factors have been proposed to explain this large injury discrepancy. Female athletes differ anatomically, having smaller ACLs and smaller notches in the knee where the ACL resides. They also have a more knock-kneed alignment at the knee. Hormones might play a role as well, as some research suggests that taking oral contraceptives might decrease the risk of a female athlete tearing her ACL.
The most important factor, though, might be biomechanical and neuromuscular differences. Female athletes tend to have different landing and cutting mechanics and different muscle firing patterns, which alter the forces at the hip and knee. These differences are important because we might be able to correct them.
Neuromuscular programs to prevent ACL injuries
The PEP (Prevent injury and Enhance Performance) Program, the FIFA 11, and other exercise programs aim to teach female athletes how to land and turn properly and build appropriate muscle strength to control forces at the knee. Players perform the exercises for 10-15 minutes as part of their warm-ups several times per week.
Some studies have shown tremendous success in decreasing the rates of ACL tears. The first study of the PEP Program implemented in the Coast Soccer League in Southern California showed an 88% decrease in the first year of the program and 74% decrease in the second for athletes who performed the PEP Program compared to players who didn’t. Other studies have shown a trend for lower risk but no statistically significant difference.
Are these programs worthwhile?
If you are a female high school or college soccer player, though, it makes sense to at least try such a program. At worst, you suffer the injury anyway despite doing the warm-up drills regularly. On the other hand, you might avoid collapsing on the field, requiring surgery and 5-6 months or more of rehab.
Of course, surgery to reconstruct the ACL can help an athlete return to soccer after this injury. Success rates for ACL reconstruction are good, but return to play is never guaranteed. Sure, many of the players on that list did return, and many of them won a World Cup. Hopefully, several others on that list win the World Cup this year. I would bet that all of them, though, would encourage young female soccer players to try to prevent ACL injuries.
Note: A modified version of this post appears as my sports medicine column in the June 12, 2015 issue of The Post and Courier.