The anterior cruciate ligament (ACL) is an important stabilizer of the knee. The ACL is often injured in sports while jumping, cutting, and sidestepping. A torn ACL often requires surgery, and can sometimes end an athlete's career. For some reason, women athletes have two to four times more ACL injuries than men. Much research has been done to try to figure out why.
This study analyzed the way high-level male and female athletes used their knees and muscles when landing jumps. Men and women basketball players from the University of Iowa were tested doing three different types of jumps: jumping as high as possible from the floor, jumping off a box about one foot high, and jumping off a box about two feet high. The athletes were tested both fresh and fatigued. In all jumps they landed on their dominant leg (the leg they would use to kick a ball).
The authors expected to find that women landed with less bend in their knees and with less activity in the hamstring muscles (the muscle on the back side of the thigh). These are known risk factors for ACL injuries. However, the results showed that women had about the same activity in their hamstring muscles, and they tended to have more bend in their knees. The results actually suggested that women should be less likely to injure the ACL when landing.
The significance of this study is unclear. The authors point out that this study had many limitations. It was small, and it only analyzed simple, planned jumps, rather than the unplanned jumps and continuous movement of real competitive play. However, the study does seem to suggest that physical differences in landing jumps is likely not the reason for the higher rate of ACL injuries in women athletes.
Ray Fagenbaum, MS, and Warren G. Darling, PhD. Jump Landing Strategies in Male and Female College Athletes and the Implications of Such Strategies for Anterior Cruciate Ligament Injury. In The American Journal of Sports Medicine. March/April 2003. Vol. 31. No. 2. Pp. 233-240.'