Rehabilitation After ACL Surgery: The Quadriceps

ACL

Nov 16

The quadriceps. What are they, what do they do, and why are they important for the ACL? In this blog post we will go over all you need to know about the quadriceps and some of our favorite ways to train it.

What are the quadriceps?

The quadriceps is a group of a 4 muscles (Vastus Intermedius, Vastus Lateralis, Rectus Femoris, and Vastus Medialis) located in the front of the thigh. The Vastus Intermedius, Vastus Lateralis, and Vastus Medialis run from the thigh bone to the patella tendon (via quad tendon) while the Rectus Femoris runs higher up on the pelvis then down to the patella tendon (via quad tendon).

What do the quadriceps do?

All four quadriceps muscles help to extend, or straighten the knee. Additionally, the Rectus Femoris helps to flex the hip. In weight bearing activities like walking, running, jumping, squatting, etc., the quadriceps help to produce force to help create motion but are vital in stabilizing the knee, decelerating the knee, and absorbing force to keep our knees healthy. The quads are often the muscle group that hold the keys to a successful rehab after ACL surgery. If they are not strong enough to absorb the forces from higher impact activities like walking, running, jumping, etc. then additional force goes through the knee and it’s passive structures (i.e. ACL), leaving them at risk of injury.

Quad strength should be 95% compared to the unaffected side before you are cleared to return to sport.

Considerations after ACL surgery:

After ACL surgery the quadriceps are inhibited due to swelling in the knee as well as the surgical procedure itself. In the early stages of rehabilitation, regaining quad function and strength are major points of emphasis as they are essential for maintaining a completely straight knee, a prerequisite to normal walking mechanics. As rehab progresses, improving strength continues to be a major focus as well as learning to load the them again in order to safely get back to running, jumping, change of direction, and ultimately return to sport. Oftentimes, ACLers have a difficult time learning to load the quads again, largely in part due to fear. By the end of rehab, your quad strength should ideally be within 95% compared to the unaffected side in addition to movement patterns that properly exhibit quadriceps loading.

How to train them:

There are a few ways you can bias quadriceps engagement during exercise: 1) Allow the knees to travel forward over the toes, 2) Keep your torso upright, and 3) front racking the weights.

Here are some of our favorite exercises to strengthen your quads:

1) Sissy Squat:

Start standing with your heels elevated on a 2 inch wedge.
Squat down, keeping your torso upright, and allow your knees to travel over your toes.
Once you’ve squat as low as you can manage, return to a full standing position.

2) Front Rack Forward Lunge:

Hold a dumbbell, barbell, kettlebell, etc. in front of your chest in a front rack or goblet position.
Step forward and lunge straight down, keeping the majority of your weight over the lead leg.
As you lunge down, allow your knee to travel over your toes.
Once you’ve lunged as far as you can manage, return to a full standing position.

In closing, the quadriceps are essential for successful ACL rehab. They are active in so many sport related movements as well as activities of daily living. Make sure that you adequately strengthen and learn to load your quads again so you can minimize the risk of re-injury after you return to sport.