Debunking the Myth of the Vastus Medialis

The quadriceps complex is comprised of four main muscles: the rectus femoris, the vastus intermedius, the vastus lateralis, and the vastus medialis (which seems to have become the most buzzworthy muscle of the four). The vastus medialis obliquus (commonly referred to as the VMO) is the middle “tear drop” shaped muscle of the quadriceps complex. Both personal trainers and physical therapists often blame generic knee pain on this guy being weak, but the literature just does not seem to substantiate that concept. If a doctor or physiotherapist has ever told you that you need to strengthen your vastus medialis, then he or she is spouting off outdated and false information.

I have seen many an article claiming that one can “isolate” the vastus medialis, or emphasize its activation, by raising the heels in a squat, by narrowing one’s squat stance, or by doing some wild exercises. These exercises are frequently prescribed to individuals with patellar tendinopathy, patellar tracking, or post-op ACL tear patients. While these concepts sound excellent in theory, the data has shown that those ideas are effectively no more than broscience. The vastus medialis and lateralis muscles contract together, and no amount of heel raise, hip external rotation, or close-stance squats will change that.

Do decline squats increase VMO activation?

The first exercise myth about the VMO is that raising the heels will increase its activation in the squat. While using Olympic lifting shoes or standing on a board will undoubtedly increase total quadriceps recruitment, as your torso will be more upright, the vastus medialis receives no preferential treatment. Rather, the vastus lateralis and medialis simultaneously work harder to squat when the heels are elevated. Similarly, the high bar squat is more quad-dominant than a powerlifting low-bar squat, and a front squat is the most quad-dominant of the three.

Does squat depth influence VMO activation?

When analyzing the angles at which the vastus medialis and lateralis are most active, Lee et. al. found that 90° or less of knee flexion was optimal. Essentially, deeper squats allow for greater vastus medialis and vastus lateralis contraction. Again, both muscles are being targeted in this instance, so the VMO is working harder, but so too is the vastus lateralis.

The other take home here is that if you want quads of the Gods, you can’t skimp on your depth. If you have to ask someone if you’re going low enough, you’re probably not! If mobility is an issue for you, then you should seek the advice of a qualified professional and dedicate time at the end of your sessions to improving your bottom position.

What about narrow-stance squats?

None of the research to date indicates that squatting with a narrow stance impacts the vastus medialis to a higher degree. In fact, it doesn’t appear that it changes the activation in any of the quadriceps muscles at all. I’m not quite sure where this myth arose, but it seems to be contradicted by the literature.

Squatting with your feet close together won't increase VMO activation,
but it may result in faulty mechanics and potential for hip impingement.

One study with Paoli et. al. looked at the EMG in 8 different thigh muscles, measuring activity in three different squatting widths and three different intensities (no load, 30% of 1 RM, and 70% of 1 RM). They tested both quadriceps and hamstrings muscles, and there was effectively no statistical difference in any of the muscles except for the gluteus maximus. No matter how close the lifters stances, their quadriceps muscles (vastus medialis included) were no more or less active at any intensity.

Surely foot position matters?

This is one that I have heard for years, and even believed myself for a while: trainers boast that externally rotating the feet will preferentially recruit the VMO, whereas a parallel foot position would lead to more evenly divided muscular recruitment. Unfortunately, no studies to date have confirmed this concept.

Murray et. al. tested twenty physically active adults in 4 different foot positions during a partial squat on the Power Tower machine. They found no real differences in EMG amplitude in differing levels of external/internal rotation. Similarly, Ninos and colleagues tested two varying foot positions (externally rotated and neutral) in the Olympic squat, and there was no noteworthy difference in vastus medialis activation.

The take home? If you have strong quads, you have a strong VMO.

Trainers have managed to come up with many creative circus-trick exercises for targeting the vastus medialis muscle, but while they might look exciting to try in videos, the basic foundational leg movements are all you need; squats, lunges, step-ups, and split squats will help you build strong quadriceps muscles, and, in turn, strong vastus medialis muscles. You can perform your leg extensions with your feet externally rotated all day, and you still won’t be able to isolate your medial quadriceps. Instead, just stick to those previously mentioned core movements and reap the benefits of your tree trunk legs!

Works Cited:

1. Caterisano, A., Moss, R. E., Pellinger, T. K., Woodruff, K., Lewis, V. C., Booth, W., & Khadra, T. (2002). The effect of back squat depth on the EMG activity of 4 superficial hip and thigh muscles. The Journal of Strength & Conditioning Research, 16(3), 428-432.
2. Dionisio, V. C., Azevedo, B. M. S., & Siqueira, D. A. (2013). Horizontal and Declined Squats in Healthy Individuals: A Study of Kinematic and Muscle Patterns. ISRN Rehabilitation, 2013. Chicago
3. Murray, N. G., Cipriani, D., O’Rand, D., & Reed-Jones, R. (2014). Effects of Foot Position during Squatting on the Quadriceps Femoris: An Electromyographic Study. International Journal of Exercise Science, 6(2).
4. Paoli, A., Marcolin, G., & Petrone, N. (2009). The effect of stance width on the electromyographical activity of eight superficial thigh muscles during back squat with different bar loads. The Journal of Strength & Conditioning Research, 23(1), 246-250.

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Where Does Your Knee Pain Really Come From?

The knees are the largest joints in the human body. Unfortunately, these large joints also seem to be an even bigger area for pain and injury. In the U.S. alone, surgeons perform around 700,000 knee replacements annually--that's a lot of bionic knees! Other knee-related injuries include ACL tears, MCL tears, patellar tendon tears, patellar tendonitis, dislocated patellas and osteoarthritis. In my opinion, many of these surgeries or injuries are easily preventable. With the proper training protocol, you can avoid knee pain and inevitable surgery down the line.

We use our knees for a lot of different activities from walking and running to jumping, squatting and lunging, and therefore they withstand a lot of impact. It is incredibly important to prioritize solid movement patterns to avoid any further stress.

I should warn you, that this post will be fairly heavy in anatomical jargon. Brace yourself.

The "knee" covers an area of four bones: the femur, the fibula, the tibia, and the patella. As a hinge joint, the knee can only flex and extend. Though its actions are simple, the muscles around it are vast and complex. Some of the important muscles that directly help the movement of this joint are the hamstrings complex (semimembranosus, semitendinosus, and biceps femoris), the quadriceps complex (vastus medialis, vastus lateralis, vastus intermedius, and rectus femoris), the calf muscles (gastrocnemius, popliteus, tibialis anterior, and the peroneals). If you feel overwhelmed with the laundry list of muscles I just mentioned, fear not! I will elaborate.

Now, we need to remember that the body acts as a chain. One part of the body reacts to the feedback of another part. What are the two major joints near the knee? If you guessed the hip and the ankle, high five! We cannot just consider the knee in the case of knee pain, but rather, we must think about how the surrounding joints are compromising the integrity of the knee. If you have poor hip or ankle stability, the knee is going to work a lot harder to compensate for the lack of stability elsewhere.

Let's start from the ground up, at the ankle. The ankle can plantarflex (point), dorsiflex (flex upwards), invert/supinate, or evert/pronate. Check your feet. Are your arches exceedingly high or collapsed? What happens to them as you squat or jump? Ideally, we want to strive for a perfect balance between pronation and supination when standing. Both of these two movements are completely natural ankle movements when walking or running, but we do not want either in excess.

If, for example, you squat and your ankle collapses (pronates) completely, you will likely experience some collapse of the knee with it. The muscles on the inside of your leg (adductors) are over-active or tight, while the antagonists (abductors) will be lengthened. Do you often feel pain in your IT bands? Well, you may fit into this category of people. Your IT bands may be tense because they're working really hard for some other guys. Think about how this position is going to effect the ligaments and tendons in your knee!

Look at the relationship between his knees and ankles in the squat.

Conversely, if you drive your knees out too much and shift your weight laterally (supinate) your feet, the opposite will happen. Your adductors are going to be lengthened while your abductors will work over time. I was one of these people. The lateral areas of my knee always caused me pain, because I was nearly rolling my ankles as I squatted.

Obviously, the ankle position will effect the knee and hip mechanics, and vice versa.

If one lacks sufficient strength in the gluteus medius and the peroneals, the lifter will, again, revert to a valgus (collapse) of the knees. Weak gluteus maximus will result in an abuse of the quadriceps complex, which is going to pull onto the patellar tendon for dear life. Put more simply, if your glutes aren't strong enough, your knees are going to pay the price.

As I said, we want to maintain a balance in how we shift our weight as we move. Too much outward shifting of the hip or ankle is just as counter-productive as shifting too much weight inward. True strength comes from a balance.

Some of these inefficiencies may be a matter of learning. You might not understand what a proper squat should look like, and there for cueing and repetition will go a long way. If cueing has not helped, then you need to follow a strengthening and mobility routine. The exercises I've listed below will be tremendously helpful.

Now that we've made it through the meat of this article, it's time to learn how to correct these faults. Figure out where you lie on this spectrum of movement dysfunction, and correct your mechanics as necessary.

Here are some great ways to mobilize the hips and the ankles:

• Subtalar eversion and inversion
• Resisted half-kneeling ankle mobility
• Soleus and gastrocnemius release
• Gluteus medius release
• Plantar fascia mobilization

Once you've mobilized, the next step is to strengthen the targeted muscles:

• Single leg RDL
• Banded squats
• Ankle step downs
• Squat off of box
• Banded eversion
• Banded inversion
• Barbell hip thrusters

Where there is pain, there is weakness and dysfunction. You don't have to "accept" being in pain. Strengthening the hip and ankle muscles are vital in perfecting your mechanics and preventing unnecessary stresses on the soft tissues of the knee. Pay attention to those stabilizers and you will save your knees for many years of heavy lifting to come.

Works Cited:

1. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 06 Jan. 2015. Web. 29 June 2015.
2. Myers, Thomas W. Anatomy Trains: Myofascial Meridians for Manual and Movement Therapists. Edinburgh: Churchill Livingstone, 2001. Print.
3. Weinstock, David. "Neurokinetic Therapy®." Neurokinetic Therapy. N.p., 22 Apr. 2012. Web. 29 June 2015.

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