That's the conclusion of a study in the May issue of The Journal of Bone and Joint Surgery.

The University of Michigan study compared 12 female and 12 male athletes playing sports associated with ligament injury risk to 14 women and 14 men active in sports with a low risk of such injuries, including bicycling and running.

In several tests that measured knee stiffness, the researchers found voluntary increase in knee stiffness after contracting knee muscles during pivoting, jumping and turning sports was greater in men than in women participating in the same sports.

Women taking part in non-pivoting sports had a higher increase in knee stiffness on muscle contraction than either men in non-pivoting sports or women playing pivoting sports.

The researchers concluded that, because women exhibited less muscular protection of the knee ligaments during pivoting or jumping sports compared to men, the rate of knee injury among women may be decreased by improving active muscle protection of the knee while women are training.

Ligaments are tough, complex structures that hold bones together. The cruciate ligaments crisscross in the knee joints and provide stability to the knees. The anterior cruciate ligament is located toward the front of the knee.

The cruciate ligaments can be injured or ruptured when athletes pivot, change direction rapidly, land from a jump, or slow down from running.

Voluntarily contracting the muscles supporting the knees stiffens the knees and may help protect the ligaments. The lower the stiffness of the muscles bracing the knee, the greater the load on the ligaments. That means that insufficient muscle stiffness increases the risk of damage to knee ligaments.

More information

Here's where you can learn more about knee injuries and disorders.