There is no difference structurally between the ACL of both men and women. But, there are differences in their laxity, commonly known as stretchiness, which is impacted by individual hormone levels and flexibility.
Some studies have shown that women tend to have more laxity in their ligaments in the knee as well as in other parts of the body. The menstrual cycle and changes in hormone concentrations may also play a role in ligament laxity.
Other studies show that female’s muscles respond differently during jumping activities than men’s—specifically showing less activation when landing. And they also show differences in muscle strength and have wider hips than males.
All of these factors also increase women’s risk of ACL tears.