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by Jonathon Sullivan MD, PhD, SSC, PBC

You have to bend your knees. Sorry if there was any misunderstanding about that.

Knee movement in the squat.
Yes, Virginia, you use your knees when you squat.

We talk all the time about hip drive in the squat, and with good reason. “Hip drive” integrates so much of this big compound movement into a single concept that the cue is indispensable.

People also talk a lot about how the hip-dominant low-bar back squat (or, as we call it, “The Squat”) preferentially loads the hips over the knees, and how the knees-out position with hips-back and prohibition of knee slide all serve to mitigate and balance the forces around the knee in a salutary manner. That's all good stuff.

On occasion I’m at pains to point out that, while going below parallel is essential (where possible, and depending on the lifter’s capacities), going “ass-to-grass” is not required or even desirable, in part because it puts additional and unnecessary stress on the knee, among many other evil effects.

However, none of this obviates the simple fact that you do, indeed, use your knees when you squat. Hip drive is essential, but there must also be leg drive and use of the quads. We don’t want knees sliding back and forth, true, but we do want knees flexing and extending. We don’t want to go so deep that our hams and calves squash together and pry the knee apart, but we do want to go below parallel, and that means that the knees do, in fact, flex.

Yes, it’s true: You have to bend your knees. Sorry if there was any misunderstanding about that.

We’ve put up videos fairly recently, on Squat Economics and the Bar-High/Hips-Low concepts, and in both cases we were skirting around the same issue. In Squat Economics, we use the idea of a “movement budget:” You can slide your knees or lower your hips, but not both. You can lean into the hole and lower your hips, but not both.

In Bar-High/Hips-Low, we’re talking about the same thing, but with a different cue. The bar-chest-shoulder complex has to stay Way Up High, and only the hips descend into the bottom. This cue helps many lifters keep a vertical bar path, which is essential.

But it all comes down to the same thing: As you approach the bottom of the squat, with the bar in the slot and your knees posted and anchored just over your toes, you have to lower only your hips. And that means that your knees have to bend.

There’s just no way around this that doesn’t lead to a miserable or failed squat. The knees, not the hips, are the primary hinge at the bottom of the movement, and that’s what they have to do: hinge! Not slide.

You can’t avoid it, so I’m asking you to embrace it: At the bottom of the squat, lower your hips by hinging your knees. This must be done without changing the back angle (Bar High! Hips Low!) and without letting the knees wave back and forth and all around (Squat Economics!).

Your knees are creaky? You have arthr-itis? Tendin-itis? Burs-itis? Old-itis?

Yeah, I get that. I’m right there with you. My knees are like bad roommates: Can’t live with ‘em, can’t make rent without ‘em. But you and I are going to have that whether we’re squatting or not. Our knees don’t want to bend, which means we don’t want to bend them.

Barring big-time joint destruction, paralysis, or instability, we just have to move past that.

It’s better to have strong creaky knees than weak creaky knees. So make the necessary accommodations. Use the Tiger Balm or the NSAID cream. Use the Icy-Hot or the Lido. Use the wraps. Use the knee sleeves. Use whatever makes your knees feel better and more supple. Do the extra set or two of light warmups to get things “oiled up.” (They do, you know: synovial fluid gets snottier and more shock-resistant and cushion-y as it’s used.)

And practice your knee hinge in daily life. We’ve talked about that, too. Use your knees. Keep them in the game, and they’ll be there when you need them, including on the platform.

Your knee joint, old or young, supple or cranky, is technically classified as a hinge joint. Use it as it was designed to be used, in life and in training: HINGE!

Jonathon Sullivan MD, PhD, SSC, PBC is a retired emergency physician and research physiologist, and the owner and head coach of the Greysteel Strength and Conditioning Clinic in Farmington Hills, Michigan, which specializes in training adults over 50. He is the author of The Barbell Prescription: Strength Training for Life After Forty, with Coach Andy Baker.

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