ACL risk factors and prevention: what you need to know

The dreaded words no athlete, young or old, want to hear are “ACL tear”. ACL tears are a rising injury in the youth sports population with higher incidences with high school aged female athletes. With the raise in this injury, let’s look at some of the risk factors and some preventative measures you can take.


What is the ACL?

The ACL is short for the anterior cruciate ligament which is a ligament in the knee that prevents excessive anterior and valgus movement of tibia (leg bone) on the femur (thigh bone). The ACL does not work alone in providing the stability for this movement. The quadriceps, hamstrings and other muscles surrounding the knee can assist the ACL in providing stability of the knee when jumping, landing, cutting, running, etc.

Risk Factors

Female athletes have been found to be most at risk to getting a ACL injury with soccer being the most common. The reason behind this trend has been found to be partly due to anatomical differences between male and female. This difference leads to a greater knee valgus during dynamic movements.

Other risk factors that have been found to increase risk of ACL injury are related to movement impairments, muscle weakness, and/or imbalances. “These include hip musculature weakness3,12,faulty muscle-firing patterns, and improper running, jumping, landing, and cutting mechanics1,8; and they often lead to valgus collapse of the knee3.”1 You may be asking how do I know if I have these risk factors? These risk factors can be identifiable through a professional functional and clinical evaluations. Another aspect to consider when looking at these risk factors are that they are not independent of each other. Improper running, jumping, and landing for example are likely due to faulty muscle firing patterns and hip musculature weakness. One good thing however, is that these risk factors can be addressed before an injury occurs.



Preventative measures for ACL injuries can make a huge impact and also provide benefits of improved athletic performance. Obtaining an functional and clinical evaluation by a healthcare professional, such as a physical therapist, can help determine if any of these risk factors are present. Targeted exercises to the critical muscles that help stabilize the knee can assist in stabilization, performance, and improved muscle firing patterns.

As with most, if not all, sports related injuries can not be completely prevented as sports can be unpredictable. However, understanding your potential risk factors can make a great impact. As Benjamin Franklin once stated “An ounce of prevention is worth a pound of cure.”

Want to know some great exercises to gain better knee stability? Stay tuned for the follow up video post! Subscribe and follow us on Facebook and Instagram!

Written by: Robert Rojas PT, DPT