The Number One Muscle Myth of Knee Rehab

Sometimes conversations go well. Sometimes they go down the toilet faster than the 2008 stock market.

A few years ago, a new surgeon had joined the practice of an orthopedist whom I had known all of my career. He wanted me to meet his new partner. So, we had lunch.

Our discussion turned technical when my longtime orthopedic friend asked me to explain my position on VMO (Vastus Medialis Oblique) strengthening for patellofemoral pain- one of the four muscles of the quadriceps muscle group – to his new partner. He said, “I think you’ll find Doug’s ideas very enlightening. He’s helped me and my patients for years.”

So, I explained that I didn’t focus on the VMO but rather on the controlled loading of the leg to promote health of the joint and neuromotor timing.

Who knew such an innocent subject about a muscle could cause such a riff.

The new surgeon said, “Well, everyone knows that you do VMO strengthening for patellofemoral pain. I can’t believe you don’t do this!”

To which I replied with a verbal left hook, “It’s a myth. You can’t isolate the VMO. It doesn’t have a separate nerve supply. You have to train all of the muscles and if you’re going to do that, you might as well be weight bearing.”

I’m not sure there’s a color of red that could describe the hue on his face right then.

He’s a surgeon. I thought he knew the anatomy. He didn’t or I guess he hadn’t stopped to think it through. He said, “Nice meeting you,” with the emotion of a piece of steel and got up and walked out. No handshake either.

I looked at my orthopedist friend and said, “I guess he won’t be sending any people our way.”

“Well, he’ll figure it out. You’re right. Don’t worry about it,” he replied.

People with knee pain, especially patellofemoral pain, are often told by clinicians, trainers, doctors  and Dr. Google to “strengthen” their VMO to improve the alignment and tracking of the patella. The thought being that by improving where the patella sits and travels, knee pain will improve. The exercises for this selective strengthening are typically quad sets, limited range of motion knee extensions with or without the addition of electrical stimulation.

But, since the VMO doesn’t have its own nerve supply, you can’t isolate the muscle from the rest of the quadriceps. And an isometric contraction of a muscle in a non-weightbearing position does very little to strengthen the muscle.

But, this isn’t just my opinion. Cerny examined this in 1995 and found no difference between the VMO activity and the rest of the quadriceps for a variety of common exercises used to target the VMO.

And another study reports:

A large number of PFPS patients can experience significant improvements in pain, function and Quality of Life, at least in the short term, with quadriceps femoris rehabilitation, with or without emphasis on selective activation of the VMO component.”

For those of you with knee pain, this means that working on your entire leg strength is preferred to attempting to isolate the VMO. Why? Because the knee serves at the pleasure of the hip and ankle. It’s stuck in between and needs to learn to work in harmony. And people with knee pain will almost always have weakness of the hip on the same side as the knee pain which means that the hip will have trouble directing and controlling motion at the knee. So, to get everyone to play together, the hip, knee, and ankle, you have to train on your feet (even if you have to reduce the effect of gravity to do it).

PS – get all the details you need to overcome knee pain – including video of tests and selected drills, in my book, The Runner’s Knee Bible. Click here for more information.

Lacey says

“I guess he hadn’t stopped to think it through.”

*This* is what separates you from the rest. And this is why I continue to follow you/your blogs through the years – I learn how to be a better thinker.

“Thinking it through” is a largely a lost skill, I have sadly realized. And “it” seems to be every field and vocation. Where have all the thinkers, creators, innovators gone?

    DD Kelsey says

    Thanks Lacey for following my writing and also for your comments. I really appreciate it.

Mike says

I’m glad that you emphasized multiple times the requirement of training on your feet. While there is a place for quad sets and similar base strengthening exercises, true function for most people includes being on their feet.

Not only is it impossible to isolate the VMO, but it’s counterproductive proprioceptively to train the VMO without considering what the rest of the body is doing during the exercise.

Thanks for continuing to teach me, DK!

    DD Kelsey says

    Mike –
    Thanks for reading and for your comments! Keep learning…it never ends 🙂

Jesse James says

Hi Doug,

Heidi Armstrong forwarded this to me. Thought I’d say hi. Love this article.

Last time I checked, we don’t walk or squat in isolated isometric movement patterns. Training a single muscle or muscle segment without training that muscle into the larger movement pattern is antiquated.

In my experience with many surgeons is they are very well trained in the structure, but not the movement. They fix structural problems. They are not movement specialists. Movement is outside of their realm of expertise. Which means that they should stay out of the movement therapy conversation entirely, unless they are also trained as movement therapists. Just like the rest of us, when it comes to something outside our realm of expertise… refer out.

I get so many clients with severe movement dysfunction post surgery, whose surgeon said “this is a simple recovery, you don’t need physical therapy;” or “just do some isometric leg extensions.” These are physical therapy protocols and should be provided by an experienced movement therapist.

Jesse James

    DD Kelsey says

    Hello Jesse –

    Thanks very much for your comments. From my view, removing the movement “threat”, which in most cases is pain, almost immediately changes a movement pattern but some ideology takes a very long time to change.

Omar says

My knees have been doing very well since starting Fusion and incorporating “on your feet” training.

I have no idea why a stronger VMO (relative to the other quad muscles) helps patellar tracking anyway. But if I wanted to focus on it, couldn’t I rotate my foot and hip in a way to lengthen that muscle more than the others, so that, while they may all be contracting together, I could put more strain on it during the contraction? Not that THAT sounds like a good idea at all 🙂

    DD Kelsey says

    Omar –

    The thinking is that because of the line of pull of the VMO (the vectors produced by the muscle fiber angulation), it would counter the lateral movement of the patella. But even if that were true, an isometric contraction performed in a non-weightbearing position would do little to counter the force experienced during something like a squat or stepping up a step.

Jimmy welsh says

I do know when I get someone to do a functional exercise like a squat, and just identify the “weak” points, and then figure out how to “train the movement”, have them do it and then everything falls into place. Like DK says, train the movement with controlled load along while training the neuromotor system, people get better and you usually find a reduction of pain. No sense with trying to isolate although open chain stuff have their place of course. Just keep it that simple. I guess I have learned over the years to do this thanks to Kelsey. Of course, always learning new and better ways.

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