The knees suffer injury more often than any other joint, in part because of their intricate system of ligaments. Women are especially prone to knee problems, and they injure the anterior cruciate ligament (ACL) twice as often as men. Knees & Hips: A Troubleshooting Guide to Knee and Hip Pain, a new report from Harvard Medical School, explains how a combination of anatomy and hormones contribute to women's weak knees. The report also outlines steps women can take to reduce their risk of knee injury.
According to Knees & Hips, the Q-angle, the angle formed at the knee where the slanting line of the femur (thigh) bone meets the vertical line from the kneecap to the ankles, is more pronounced in women than in men because women tend to have wider hips. This increases strain on the knee. Researchers also speculate that high levels of estrogen can make the knee ligaments more flexible while weakening their shock absorption.