Molly Federl of Scituate, Massachusetts, started out shaking pom-poms and doing forward rolls as a cheerleader in sixth grade. By high school she was performing acrobatic midair maneuvers like the front hurdler and the pike, at both varsity games and statewide competitions. In February 2007, while the 16-year-old was performing a tricky series of jumps at a league meet, she heard her knee literally pop. It didn't hurt too much, so she kept going. By the time the two-minute routine was over, Molly had to be carried out of the gym and rushed to the ER. She'd ripped her front knee ligament, or ACL, clear off the bone. After reconstructive surgery, she hobbled on crutches to the prom that spring and endured extensive rehab therapy all summer. Still, Molly has no regrets. "Maybe staying out there wasn't the best idea," she says. "But if I hadn't, our team would have lost. Instead, we came in second."
One of the most common type of sports injuries, ACL tears are the bane of athletes whose sports require quick pivoting or jumping. Soccer, basketball, and football players, along with cheerleaders and skiers, are especially vulnerable. Some 20,000 cases occur among high school students each year -- most of them girls -- according to the American Orthopedic Society for Sports Medicine. Compared with boys, girls have looser muscles overall, offering them greater flexibility but less support for bones and ligaments. And their leg muscles tend to be unevenly developed, with stronger quadriceps at the front of the thigh and weaker hamstrings at the back. As a result, girls are two to eight times more likely to incur ACL damage -- and suffer the long-term consequences, which include progressive and permanent loss of cartilage, stiffness, pain and, in some cases, osteoarthritis of the knee showing up as early as 30 years of age.
The good news is that ACL injuries can largely be avoided with strength training, which corrects the muscle imbalance, and plyometrics, a form of jumping exercise that increases power and speed. Unfortunately, many coaches don't put enough stress on preventive measures, and even when they do, it's still up to students to do their part. "The routines we do are so hard and take so long to learn, there's not a lot of time left over for conditioning," says Molly. Since returning to cheerleading last August, she tries to hit the gym three times a week, but admits she often doesn't make it. At her doctor's recommendation, Molly now uses a knee brace, which reduces the risk of re-injury. "She has to wear it when she does her routines," says her mom, Beth Baron. "As long as she is in good physical shape, we're happy."