Certified Personal TrainerCESSports Medicine

Why is the tensor fascia latae and vastus lateralis overactive if a client’s knees cave inward during the Overhead Squat test?

By: Brian SuttonMS, MA, NASM-CPT, CES, PES

Q: Why is the tensor fascia latae and vastus lateralis overactive if a client’s knees cave inward during the Overhead Squat test?

I receive this question quite a bit from the NASM trainers. I hope this helps explain some of the rationale.

If the knees cave-inward during the Overhead Squat test, there are several muscles, connective tissues, and joints that can be implicated in this dysfunction. However the Overhead Squat test is designed to give fitness professionals a general overview of movement impairments and guidance for improving these dysfunctions. Diagnostic evaluations are beyond the scope of personal trainers and should be reserved for licensed professionals (i.e. physical therapists, MD’s).

The tensor fascia latae (TFL) is implicated as overactive because it can concentrically internally rotate the femur and can also externally rotate the tibia (due to its attachment to the IT-band) during closed-chain squatting movements. This often occurs in conjunction with overactive adductors. Typically the TFL and adductors compensate (synergistically dominate) for weak hip external rotators (i.e gluteus medius, gluteus maximus) to maintain frontal plane stability of the LPHC. Simply put, if the gluteals are weak, the TFL and adductors are forced to overwork to maintain pelvic stability. However, a byproduct of this will be knee valgus (knock knees).

The vastus lateralis is implicated because when overactive it can cause lateral tracking of the patella and influence (or become influenced) by knee valgus motions. This usually occurs in conjuction with abnormal contraction intensity and onset timing (i.e. weakness) of the vastus medialis oblique (VMO).

Each of the quadriceps muscles either exerts a medial or lateral pull of the patella as it slides in the groove (femoral trochlea). When these forces balance each other, they cooperate to track the patella through the groove with little stress to the joint surface. If they do not balance each other, the patella may not track optimally. The degree of lateral pull exerted by the quadriceps is often referred to as the Q-angle. Factors that increase the Q-angle also tend to increase knee valgus. These factors include an overstretched medial collateral ligament (MCL), hip internal rotation and adduction, and foot pronation.

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National Academy of Sports Medicine

National Academy of Sports Medicine

Since 1987 the National Academy of Sports Medicine (NASM) has been the global leader in delivering evidence-based certifications and advanced specializations to health and fitness professionals. Our products and services are scientifically and clinically proven. They are revered and utilized by leading brands and programs around the world and have launched thousands of successful careers.

14 Comments

  1. September 19, 2012 at 6:50 pm — Reply

    Thanks for a good explanation Brian! I just got my CES a few months ago and it has already more than paid for itself! I wish all trainers were required to take this cert!

    • November 18, 2012 at 6:48 am — Reply

      Understanding Knee Pain Sensible living Posted by root 25 menitus ago () Even though vastus lateralis is not used to flex the ankle joint it is used in the action of extension of the leave a comment name mail will not be published website powered by wordpress enhanced by one theme Discuss | Bury | News | Understanding Knee Pain Sensible living

  2. October 25, 2012 at 2:49 am — Reply

    I am so much excited after reading your blog. Your blog is very much innovative and much helpful.

    • November 16, 2012 at 6:03 pm — Reply

      Gage, Thanks for the comments. I think the need to do wehgit training in sprinting is probably far greater than soccer or other team sports. As you noted, the difference between winning and losing in sprinting is measured in hundreds of a seconds. These small differences will also determine whether you win or lose the ball in soccer, but the outcome will more likely be determined by a variety of skills such as anticipation, balance, coordination, game sense, agility, etc. Whereas in sprinting its a pure power game, far less skill involved. That being said, I would be curious to see how far one can go in sprinting with no wehgit training at all. My guess is that many of the top guys could have achieved world class status even without ever walking into the wehgit room. They probably wouldn’t reach their peak of course.

    • November 18, 2012 at 5:32 am — Reply

      , I would be curious to see how far one can go in spnintirg with no weight training at all. My guess is that many of the top guys could have achieved world class status even without ever walking into the weight room. They probably wouldn’t reach their peak of course.

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  5. August 14, 2015 at 12:32 pm — Reply

    […] the muscle imbalances – the overactive muscles and the underactive muscles. In this case, our overactive muscles would be our adductors (inner thighs), bicep fermoris – short head (little tiny muscle on the […]

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