The Cold Hard Facts About ACL Tear Risk Factors

All athletes cringe at the sound of the words “ACL tear”. Fortunately as our understanding of the nature of ACL injuries and medical technology advances, these injuries have become less common, and less of a risk to an athletic career. But what exactly leads to an ACL tear in the first place?

What Causes an ACL Tear?

Commonly accepted research figures show that 30% of ACL tears occur as a direct result of a blow to or contact with the knee. The remaining 70% of ACL tears occur without contact. These incidents happen when the athlete pivot or “cut”.

Girls vs. Boys: Anatomic Risk Factors

Did you know that boys and girls actually have distinctly different figures related to their likelihood for ACL injury?

In fact, ACL tears are actually more common in females than in males. Much of this can be attributed to the fact that women tend to have hips which are set wider than those of their male counterparts. This angle causes increased stress on the knee joint.

A Nervous Contribution: Biomechanical Factors

Neuromuscular control plays a surprisingly large role in the risk of ACL injury. Neuromuscular control is, more or less, the ability of your nerves to control your muscles. This plays hand in hand with something called proprioception, the ability of your body to provide information from the body to the brain.

If there are issues with either of these functions it can lead to the knee being put under compromising levels/angles of force. Either the muscular groups supporting your knee are unable to stabilize the joint, or don’t register than they are supposed to be stabilizing the joint.

Trunk Stability

It’s been found that individuals who cannot stabilize their hips and trunk are at especially high risk for non-contact ACL tears. This inability to stabilize the trunk and hips causes an increased transfer of force through the knee joint accompanied by irregular muscle activation in the leg, further exposing the joint to injury. This trunk stabilization is often lead by the proper activation of the hamstrings and gluteus medius as the athlete moves through a plane of motion.

‍