A tear of the anterior cruciate ligament (ACL) in the knee can lead to chronic pain—and cut short athletic careers. ACL injury brings both weekend warriors and professional athletes to massage. ACL injuries can also contribute to osteoarthritis, another condition many massage clients present with.

Women are two to eight times more likely than men to suffer an ACL tear, and a new study indicates a combination of body type and landing techniques may behind this discrepency.

In two new studies published online this week in the Journal of Athletic Training, lead author Marc Norcross of Oregon State University documents how women who were asked to undergo a series of jumping exercises landed more often than men in a way associated with elevated risk of ACL injuries, according to a university press release.

Men and women both tend to land stiffly, which can lead to ACL injuries, but women were 3.6 times more likely to land in a “knock-kneed” position, which the researchers say may be the critical factor leading to the gender disparity in ACL tears.

“We are trying to create a prevention strategy that is sustainable and will be widely used by high school coaches,” Norcross said. “A lot of athletes do come back from an ACL injury, but it is a long road. And the real worry is that it leads to early onset arthritis, which then impacts their ability to stay physically active.”