ACL tears, which can end a promising athletic career and usually require surgical repair, occur during sudden stops and turns, or during an awkward landing, such as when a basketball player jumps up and lands on another player's foot. Women athletes are three to four times more likely than men to tear this ligament. A new study, which was presented at the American Academy of Orthopaedic Surgeons in California in early February, videotaped athletes. Researchers saw that women run differently than men, and as result, they rely more on the quadriceps muscles in the front of the knee, rather than the hamstrings in back.
Men run in a more crouched position, while women's knees and hips are straighter.
Edward G. McFarland, M.D., director of the Division of Sports Medicine and Shoulder Surgery for the Johns Hopkins Medical Institutions, explains in this InteliHealth interview why this difference in posture might be the answer to the puzzle. Women tend to run more upright than men when they run. Two recent studies show that women do indeed have different body mechanics than men when they run. They don't have as much flexion in the knee when they do cutting maneuvers, and they put more stress on the inside of the knee when changing direction. One of these studies was on recreational athletes so it may not extrapolate to highly-trained female athletes.