Back

Knee Ligamentous Laxity: It's a Gender Thing

Joint laxity may be a factor in anterior cruciate ligament (ACL) tears. Since women have more ACL injuries than men, laxity may be the cause. In this study joint laxity in men and women was measured. All subjects were involved in intercollegiate athletics.

A special device called an arthrometer was used to measure the motion of the lower leg bone (tibia) as it moves forward against the thighbone (femur). This motion is called a "drawer" motion. Too much forward motion, called the anterior drawer sign, suggests ligamentous laxity.

Range of motion in other joints was also measured. These measures were used to judge overall ligament laxity. Several positions were also used to assess laxity such as being able to touch the thumb to the forearm with the wrist bent. Bending forward and touching the palms to the floor with the knees straight was also measured.

The results of measurements taken showed that general joint laxity is linked with ACL tears in women. The ability to hyperextend the knee was found in both mend and women with ACL injuries. Both groups of men and women with ACL injuries had greater elbow extension, too.

The authors conclude that this study shows a link between knee hyperextension and ACL tears in all athletes. It still doesn't explain why women have higher injury rates. More study of this problem is needed to find a way to prevent ACL injuries in all athletes, but especially among women.

References: Tamara A. Scerpella, MD, et al. Ligamentous Laxity and Non-contact Anterior Cruciate Ligament Tears: A Gender-Based Comparison. In Orthopedics. July 2005. Vol. 28. No. 7. Pp. 656-660.

Back