Every high school sports season, there are athletes who tear their ACL. When a teenager jumps or pivots fast to get a ball they may feel a pop in their knee, but usually can walk off the field. But within 24 to 48 hours the teen’s knee is severely swollen.
If your teenage athlete is a girl, her risk of tearing her anterior cruciate ligament (ACL) is four to six times greater than a boy’s. Why? At first, researchers thought hormones and girls’ body structure increased their risk. But studies now indicate those are minor points.
More likely, girls are at greater risk for ACL tears because of two factors, both preventable:
- Biomechanics. Girls tend to hold their bodies more upright than boys when they jump, cut and pivot. They also tend to let their knees turn inward into a knock-knee position.
- Muscle imbalance in the thighs. Girls’ hamstrings — the muscle in back of the thigh — are generally weaker than their quadriceps, the main muscle in front of the thigh. Girls’ quadriceps can overpower their hamstrings, which puts pressure on the knee.
Research shows that prevention programs can reduce the risk of ACL tears in girls by over 80%. Unfortunately, many coaches aren’t aware of prevention programs and don’t incorporate them into training programs.
Girls who strengthen their hamstrings and learn to place their knee directly over their foot can protect themselves. Physical therapy can help teens develop workouts and habits to help protect them from knee injuries. Unlike other ligaments, a torn ACL cannot heal itself. Young athletes who want to stay active throughout their life usually require surgery to repair a torn ACL.
The surgery is very successful in stabilizing the knee and restoring function, but if you’ve torn your ACL once, you have a higher risk of premature arthritis and tearing the ACL again in the same knee or the opposite knee. Prevention is a far better solution.
Reviewed by: Richard Gayle, MD
Last reviewed: March 2024
