Duke Medicine: Just bend

Our knees are meant to bend, so let them. Research suggests that most knee injuries happen when athletes land or turn with their knees too straight.

“If you were to jump up one inch off the floor and land with your knees straight, you would feel the shock going from your feet to your head,” says William Garrett, MD, PhD, an orthopedic surgeon at Duke and chairman of the sports medicine advisory committee for the U.S. Soccer Federation.

“But if you let yourself bend a lot," he says, "you are absorbing all that energy with your muscles rather than your joints.”

The most serious knee injuries happen when a ligament tears or breaks, and the most commonly torn is the anterior cruciate ligament (ACL).

Women are five to 10 times more likely than males to suffer a torn ACL. Why women?

“Some of the factors are things we can’t control, primarily hormonal factors such as the increase in estrogen and the lack of testosterone,” says orthopedic surgeon Alison Toth, MD, director of the Duke Women’s Sports Medicine Program and team physician for Duke’s women’s athletic teams. These hormonal differences can result in women having more lax ligaments than men.