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The VMO (vastus medialis oblique) is a quadriceps muscle, mainly used in knee extension, and stabilization of the knee during movement (6). The VMO is important because it assists in, and is directly activated when extending the knee. This is important in everyday movement, but also when lifting heavy loads, such as during squats, lunges, and leg presses.
Before I delve any deeper, I want to get this out of the way up front. I am not a doctor, medical practitioner, or physical therapist. I am a personal trainer. While I have worked with clients in a post-rehab setting, and helped many clients manage and work with their pain and injuries through strength training, this has been done in the context of the scope of practice of a personal trainer. This article will be written as such.
What does that mean? It means that nothing in this article is meant to diagnose, treat, or heal your injuries. However, the things contained in this article may help you manage pain or injury during your training, give you some context on the evidence for returning to training after a setback, and provide you with a path forward towards reducing pain and improving performance. I will also try to keep this article fairly general, succinct, and actionable, while still attempting to be accurate. Now that that is all sorted, let's get moving, shall we?!
In my estimation, there are essentially two, sometimes conflicting, schools of thought on the matter of strengthening, building, and rehabbing the VMO, and other similar injuries. The first, is that a general strengthening protocol is better. You needn't worry about direct VMO work, because the VMO will be trained sufficiently by doing things like squats, lunges, and leg extensions. Therefore, it is unnecessary, and possibly even a waste of time / training resources, to engage in VMO work that focuses solely on activating or stabilizing the VMO.
Moreover, it may actually be counterproductive. Direct VMO work removes time from your program that you COULD spend getting better at more general movements. These general movements provide a more broad base of strength and muscle development than VMO specific exercises. These movements are also more applicable to everyday activities, such as standing up, ascending stairs, and bending down. This is likely more pertinent for the average person / goals.
Direct VMO training also artificially limits load. Severe load reductions may be necessary in the beginning or the recovery process, depending on the severity of the injury or weakness. However, limiting load too much may slow progression and increase the amount of time it takes to recover (1). It is a difficult balance, for sure.
The second school of thought is that direct VMO work is necessary, or at least the most direct way to rehab the VMO. It makes sense right? That principle of specificity states that training adaptations are tightly coupled to mode and frequency of exercise (2). If you want to strengthen the VMO, the principle of specificity would hold that the best way to do this would be through direct VMO work, correct? Not necessarily.
The problem with option 2 is that it may not optimize the load component of training. You will likely be able to squat more weight than you can lift on an adductor machine, and also systematically subject your entire body to more load and training stress by doing so. We know that muscle hypertrophy is a complex process, and limiting it to simply "do exercises that target this muscle" is a very one dimensional approach that I do not subscribe to (3). Though the adductor machine may activate the VMO more in EMG analysis, does this really give the results we're looking for (I.E. more motor control, increased strength / muscle cross sectional area, and ultimately, recovery to normal movement / activity)?
For example, this 2010 study looked at the difference between direct VMO retraining, and a general quad strengthening protocol for strength (4). The study found that in the short-term, the specific VMO rehab exercise protocol that centered on motor control retraining did indeed create a larger change in a stair ascent test, but this change was not significant compared to the general training group. In the stair descent test, both groups saw a significant improvement, with the improvement favoring the more specific VMO targeted exercises. However, the general quadriceps strengthening group saw increases in quad / VMO strength, while the motor control retraining group did not. Further, both groups saw similar functional changes in a follow-up test after training, indicating both protocols lead to similar long-term recovery. What does this mean?
Like many exercise recommendations, VMO training, rehab and strengthening should be specific to each person’s situation and the goals. This study I quoted comparing interventions also did not include an intervention utilizing compound exercises. Compound exercises are exercises that move multiple joints at the same time under load. There is statistically significant data that favors implementing compound exercises in a training program, when reduction in pain is the goal (8). This isn’t to say that single joint exercises should be avoided, just that perhaps we shouldn’t look to ONLY isolate the muscle that we are interested in rehabbing.
Based on all of the above, I would perhaps suggest implementing a program solidly footed in compound movements, like squats, lunges, and leg presses, that also incorporates single joint movements like leg extensions. Finally, I would add a bit of the VMO protocols used in the study (source 4), if you are rehabbing a VMO injury specifically. What this may look like, is simply taking an existing well-rounded exercise program, and adding in a few of the exercises from the table below, taken directly from “Effects of vastus medialis oblique retraining versus general quadriceps strengthening on vasti onset”, Bennell 2010. In order to do so, you may need to temporarily reduce the volume of your current training program to make room.
QS exercises are “quad strengthening exercises”, whereas MCR exercises are “motor control retraining exercises”. Depending on the severity of your VMO deficiency, you may need to start with more or less of one type of exercise. Since the VMO motor control targeting exercises (MCR) tend to work better in the short term, I would likely use more of those in the beginning, but ditch them as you progress. If you already have decent strength, you might not need to use them at all. I may include some of the quad strengthening (QS) exercises as permanent fixtures in your program, while maintaining compound exercises like squats, deadlifts, leg presses, and lunges, as the main core of your regimen.
I hope you find this article helpful. If you have any questions or concerns, please direct them to JonnyReps@gmail.com.
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