Since female athletes tear their anterior cruciate ligament (ACL) six to eight times more than men who play the same sport, a sports medicine surgeon suggests a new approach: teach women how to jump more like men.

"Studies have shown up to a 50 per cent decrease in ACL tears in female soccer players who took part in a jumping and landing program," says Dr. Patrick McCulloch, an orthopedic surgeon with the Methodist Center for Sports Medicine in Houston.

"Most of these injuries occur in sports with a lot of cutting and pivoting such as basketball and soccer."

McCulloch says the problems center around the fact that many women land with their knees straight and kneecaps pointing inward, which puts a lot of stress on the ACL.

Men, he says, tend to jump with their feet further apart with more bend in the knees.

By teaching women to jump more like men, through a six-week plyometric exercise program, women can train their muscles to develop a "muscle memory" to help their hamstrings fire off at the right time and help them land with a bend in their knees, he says.

"The jump program not only strengthens the knee, but it also helps teach female athletes the motor control required to cut, jump and land properly," says Kelly Osburn, a Methodist Center for Sports Medicine physical therapist who helps female athletes recover from ACL injuries.

"Most of my patients leave physical therapy stronger than they were before their injury."

In a separate study, women were found to be more vulnerable to knee injuries from high-impact sports a week before their period is due.

Researchers from the University of Texas at Austin and University of North Carolina at Chapel Hill found that the bundles of nerves in the knee had firing rates that were significantly higher in the late luteal phase, about a week before a woman's next period, compared to earlier in the menstrual cycle.

The researchers noted that this difference in firing rate could affect the stability of the joint, potentially affecting its susceptibility to injury. That study was presented in October at The Integrative Biology of Exercise conference held in Colorado, US.