The ACL Vaccine

The Anterior Cruciate Ligament (ACL) is a structure in the knee that stabilizes that joint from rotation and shearing forces. If you follow sports or know an athlete, you've probably heard of the ACL. An ACL injury can mean the end of an athlete's season or sports career. And although surgery is very successful at restoring knee stability and function, the limb is never quite the same after a traumatic injury and surgery.

What if we could develop an ACL vaccine? It would prevent ACL injuries from happening in the first place and help athletes have long, successful seasons and careers. But before I tell you about the ACL vaccine, let's talk a little about the ACL and how it gets injured.

Rotation and injury

Most ACL injuries commonly occur during quick movements that are non-contact (not involving a collision with another athlete) and rotational in nature, like jumping and landing, pivoting, running or quick changes of direction. The ACL can be sprained, where it remains intact but is quickly stretched beyond its normal length, or it can be torn.

If the ACL is torn, surgery is an option but it's not necessarily the only option. It depends on the athlete's needs and what their physician recommends. You can live without an ACL, but it won’t allow that athlete to perform any running with quick changes of direction or jumping and landing. If the ACL is only sprained, it can be rehabbed successfully with physical therapy.

So now you know a little bit about the ACL and what it does, how can we vaccinate athletes from getting injured? Since the majority of ACL tears are non-contact, we can vaccinate athletes by reducing or abolishing their risk of injury by analyzing their body mechanics and improving their ability to withstand eccentric and rotational forces.

How to vaccinate against ACL injuries

The vaccination begins with a movement analysis and physical exam. We look at the risk factors that lead to ACL injury and assess whether the athlete is at high risk, moderate risk, or minimal risk. From there, we can develop an exercise program to mitigate that risk and improve the athlete's body mechanics.

First, the physical exam will assess basic measurements for the trunk, hip, knee, ankle, and foot. We’ll measure range of motion, joint mobility, strength, and tissue extensibility. Special tests that assess the integrity and strength of the ACL and other ligaments in the knee can be performed as well.

Using slow motion video analysis, we can assess running and landing mechanics. The risk of ACL injuries increase when the knee gets into a bad position when running, jumping, or landing. Once we do all the testing, then be can start a customized exercise program that address any deficits we find.

The exercise program will include several things: ankle mobility, hip strength, knee mobility, hip and ankle motor control/coordination, balance, and single-limb stability. The program should be very individualized because not all athletes are alike nor are the loads from sports alike. By performing a customized program that addresses single-limb stability and strength, we can reduce and abolish the risk of ACL injuries with sport. We start with a bilateral exercise like squats. Then move onto single limb exercises. The movement mechanics that make for a good squat also can help to stabilize the body for single limb exercises.

We have several different techniques to improve single limb stability, but the two exercises above are a good starting point to vaccinate against ACL injuries.

If you want more information on how to vaccinate yourself or an athlete you know, please contact PAR 5 Physical Therapy to schedule a free consult.