Doctor explains why knee injuries are 3-times more common in teenage girls

As many as 250,000 people suffer an ACL injury each year in the U.S., and teenage female athletes are three-times more likely than their male counterparts to suffer an ACL injury.

Experts say anatomical differences, hormones and a lack of conditioning and balance training may all factor into why girls are more likely to get hurt.

When we met Peyton Thomas in the winter of 2020, she was working to come back from her first ACL injury.

It happened when she was 14 years old and trying out for a club soccer team.


"I was going into a tackle and my foot got stuck in the ground and I hyperextended my knee," Thomas said. "And, then, I walked off the field to get some ice and stuff, and I felt really shaky."


An MRI at Children’s Healthcare of Atlanta showed she had a complete tear of her ACL as well as tears in her medial and lateral meniscus.

She was crushed because tearing her ACL meant she would be sidelined for 9 months to a year.

"They said I would have to have surgery, and I would have to get my ACL repaired, and my meniscus repaired," she said.

Thomas underwent two ACL surgeries for separate injuries with Children's Healthcare of Atlanta pediatric orthopedic surgeon Dr. Crystal Perkins.

Typically, she says, these are not high-contact sports injuries.

"So the majority of ACL injuries are open field, non-contact injuries," Dr. Perkins said. "The knee shifts, and the ACL tears as the knee shifts. But, most commonly, they're twisting, pivoting or cutting injuries."

Perkins said 60% of her ACL patients are teenage girls, and most are single-sport athletes, who train for and play the same sport all four seasons of the year.

That singular focus, she said, can leave them vulnerable to a knee injury.

"Each sport brings out different muscle balances and muscle strengths, and when you're focused solely on one sport year-round, it sets you up for some of those imbalances," Dr. Perkins said. "We know that hip and core strength is a big component of why people tear their ACL."

It is not clear why young women are more likely to suffer an ACL injury, but Perkins says, their anatomy, hormones and biomechanics may all play a role.

Helping players like Thomas build up their core and hip muscle strength and balance can help.

"We know, as you jump and land, your glute muscles and hip and core muscles contribute to the mechanics of how you land," Dr. Perkins said. "So, when you jump and you land and your knee turns inward, that has a significant impact on the ability to tear your ACL, as opposed to if you jump and land with your hip and ankle all in a straight line."

Dr. Perkins believes the best way to protect younger players is to teach them how to prevent injuries as part of their training.

"The difficult thing with sports, is, oftentimes you show up, you work on some drills, you scrimmage and then practice is over, and you go home, and there was not a great warm-up or cool down or strength-training component to things," Perkins said. "So, we spend a lot of time working with them on jumping and landing mechanics and strength training and discussing that those are really the key elements that allow people to successfully move from being high school athletes to college athletes."

Peyton Thomas has recovered from her ACL injuries and is now playing again. She plays for Campbell High School and the club soccer team SSA.