Female athletes are six times more likely to injure the anterior cruciate ligament (ACL) of the knee than male athletes. The exact reason for this remains a mystery. There may be several factors involved. Scientists suggest anatomy, poor exercise training, or hormones as possible causes.

Sports scientists have also found greater forward slippage of the tibia (lower leg bone) during sudden stops or stop-jumps. The shear force during the landing phase of these activities may cause the ACL to tear. The ACL is one of two ligaments that cross inside the knee joint. It keeps the tibia from slipping too far forward.

Two new bits of news have been added to the data bank of information on ACL tears in women. First, it's been found that women have more coronal plane motion in the knee compared to men. This means there's more forward slippage naturally. A second new finding is the role of balance on knee joint stability.

Each new study brings us closer to finding ways to prevent ACL injuries. This information is also being used to study which exercises are best for retraining after injury to this ligament.