"You run like a girl!'

When it comes to knee injuries, that old taunt - sexists as it is - could actually have some truth behind it.

The risk of painful anterior cruciate ligament injuries is between two and eight times higher in female athletes than in their male counterparts.

Why that is, exactly, is still somewhat unclear. Hormones are a possibility, as ligaments are more lax during menstruation. Anatomy offers another list of possible causes - wider hips that cause the knees to point in toward each other and a smaller notch in the femur that can cause rubbing and fraying of the ligament.

Even if those are the true causes, however, there's little anyone can do to change them. As someone once said, anatomy is destiny.

So the focus is turning to what can be controlled - specifically, how female athletes run, jump and move.

Girls on average - especially in basketball and soccer - play more upright, more mechanically, said Dr. Joseph Congeni, director of sport medicine at Akron Children's Hospital, which puts the knees at increased peril.

It doesn't have to be that way, though. Girls' ACL injury-prevention program have sprouted nationwide, teaching how to run, jump, land and pivot differently.

To be worthwhile, prevention programs need three basic elements - strength training, not just for the quadriceps and hamstring, but also for trunk muscles like the abdominal; balance training coupled with spatial awareness; and jumping exercises, such as one-legged hops, doctors say.