Why don't people shove knees out?

[JimtheConquerer]

So, I'm guilty of this too. But what is the cause for people to do the charleston (bring knees in rather than keeping them shoved out as the weight gets heavy)?

It seems like dropping my knees gives a bit more oomph to getting the weight up.

[Tom Campitelli]

I am going to take a guess at this and I reserve the right to change my mind since I have not thought this through very much. When people's knees track medially, or valgus, to use the parlance of our times, during the squat, they are shortening the adductors. The adductors function largely as hip extensors during the squat, provided the knees stay out. Letting them come in tends to flex the knees slightly, shifting work to the quads, while removing some of the contributions of the hip extensors. Knees coming in also often occurs in conjunction with lifting the chest. So, knees coming in probably allows for a slightly more upright posture as the knees rebend and takes some moment force off of the torso. It also potentially slows the bar speed, deprives the spinal erectors and hip extensors of some work in favor of the quads, and puts a twisting force on the knee. It is a function of standing up "by any means necessary," instead of using the musculature in concert to drive the bar up. That's my first crack at this.

[tfranc]

I've noticed when I let my knees cave a little, it's easier to maintain lumbar extension. I'm guessing lumbar extension is coupled with inward rotation of the knee. But I agree, it does make the squat feel like crap when the knees really cave

[Tom Campitelli]

I think it is probably more correctly associated with lumbar overextension.

[Adam Nelson]

At what point does the "knees out" pattern become stronger, thus becoming the default ("by any means necessary")? At some point it has to, right? Otherwise it seems antithetical to the "most weight over largest ROM" criterion. Do the shear forces caused by the "knees in" pattern make it unsustainable in the long run? I'm not advocating for a "toes forward" squat model or anything, I'm mainly just wondering when, if ever, the urge to allow knee cave clears up.

[Josh K]

I've noticed that caving knees are usually accompanied by driving the hips backwards instead of up, and that making the hips drive straight up fixes or greatly improves knee cave without even needing to think about what the knees are doing. It's the first thing I look for now if the knees are caving in on the initial drive out of the bottom, and if it's happening then fixing it usually fixes the knees too.

[Tom Campitelli]

At what point does the "knees out" pattern become stronger, thus becoming the default ("by any means necessary")? At some point it has to, right?

Not necessarily, although ideally this would be the case. Some movement patterns die hard. I have trainees that I have to cue on the same things all the time.

Otherwise it seems antithetical to the "most weight over largest ROM" criterion. Do the shear forces caused by the "knees in" pattern make it unsustainable in the long run?

Remember, we are not talking about powerlifting here, but strength training. We want to train the most muscle mass, over the greatest effective ROM, and use the most weight possible. Taking muscle mass out of the equation in the hopes of moving more weight is rarely effective, but it also violates our criteria for strength training. We want everything to get strong. Letting the knees come in definitely subjects the connective tissues of the knee to higher stresses that can cause pain and injury.

I'm not advocating for a "toes forward" squat model or anything, I'm mainly just wondering when, if ever, the urge to allow knee cave clears up.

In some people, it never does. In other people, it happens quickly. While in others, their knees naturally stay out. The whole deal is entirely individual and dependent upon the trainee.

[Tom Campitelli]

I've noticed that caving knees are usually accompanied by driving the hips backwards instead of up,

That can definitely happen, too. That is a bad combo. Flexing the hip while shortening the hip extensors. It does not make for better squats, unfortunately.

and that making the hips drive straight up fixes or greatly improves knee cave without even needing to think about what the knees are doing.

Sometimes.

It's the first thing I look for now if the knees are caving in on the initial drive out of the bottom, and if it's happening then fixing it usually fixes the knees too.

Sometimes.

[marcf]

I was watching this Ben Rice video this morning and found it interesting that his knees didn't seem to move outward at all until the bottom of his squat, probably when it's most necessary to make room for his stomach so he can hit depth:

Use negativity, don't dwell in it - YouTube

He also seems to fold over quite a bit toward the bottom like Layne Norton does.

[tfranc]

I think it is probably more correctly associated with lumbar overextension.

Good point