Kylie Howe has been playing sports year-round since first grade, and her Uncle Paul says she's a tough competitor.
"Kylie's not one to back down," Paul Hansbury explained.
But last January, that tenacity got Kylie in trouble during a basketball game.
Kylie tells us, "Me and this girl were kind of going at it the whole game, and she came at me laterally...and I fell instantly."
Kylie had torn the ACL and meniscus in her left knee and she needed surgery.
Dr. Theodore Ganley is a sports medicine specialist at Children's Hospital. He's seen this injury often in his studies of Philadelphia area schools.
"We noticed a 400% increase in ACL injuries in kids in the past 10 years," said Dr. Ganley.
And there is a big difference between the boys and girls.
Dr. Ganley says, "The girls have up to 8 times as much chance of having an ACL as the guys."
Dr. Ganley thinks the trend toward starting sports at a younger age and doing a single sport year-round are contributing to both ACL and overuse injuries. So he and his colleagues developed an injury prevention program called Ready, Set, Prevent.
Videos on the hospital's website detail exercises for warm-ups, flexibility, strength, and balance aimed at preventing lower extremity injuries.
Kylie should be cleared for track this spring, but she missed her last season in her favorite sport - soccer. Dr. Ganley says better preparation won't prevent every injury, but it will keep more kids in the game.
You can get more information on the Ready, Set, Prevent exercises here.