Sliding Knees

[mgil]

Is there a solid argument that knee slide creates a lack of efficiency in the squat?

[Cellist]

No

[damufunman]

Just walking through a couple possible (counter?)arguments here:

ETA: Knee slide is purported to shorten the hamstrings, which kills hip drive out of the hole. Though I see no mechanism of the hamstrings contributing to knee extension, and in fact, if anything, they work against it. If your glutes muscular buttocks are strong enough though this might be ok due to Lombard's paradox, but it seems having the hamstrings contracting hard is counter to standing up. Well shit, I can't even come up with an argument FOR it.

Original response:
Knees sliding forward at the bottom is lengthening of the calf muscles/tendons. With the Achilles tendon being the thickest in the human body, and also I believe pretty long, should be good for storing elastic energy, a la part of the stretch-shortening cycle. So knees sliding forward then back at the bottom of the squat could conceivably give some assistance in hips shifting backward, or shortening of the moment arm for the knee in the hole/near parallel, which is the least mechanically efficient point.
So knee slide might actually help you through the sticking point? At which you then bring your hips forward to take some load off the glutes so you can finish the lift.

I think I just argued against knee slide being bad?
Don't know how valid it is though...

[mgil]

So knee slide might actually help you through the sticking point?

I think knee slide might help with getting out of the bottom, basically by the mechanism you described.

[damufunman]

So knee slide might actually help you through the sticking point?

I think knee slide might help with getting out of the bottom, basically by the mechanism you described.

I tried arguing for it in update to above... still can't get my head around it (or hamstrings for that matter).

[ChasingCurls69]

So knee slide might actually help you through the sticking point?

I think knee slide might help with getting out of the bottom, basically by the mechanism you described.

I tried arguing for it in update to above... still can't get my head around it (or hamstrings for that matter).

That seems to be an argument for why we should squat-morning our squats by having the hips move back that way and then forward again. I don't have a convincing argument off the top of my head, but some vague consideration that the hamstring's isometric contraction helps maintain the back angle alongside the erectors, and that squatting in the way described above with knee slide feels like shit and kills my bar speed on heavy squat reps.

[OCG]

ETA: Knee slide is purported to shorten the hamstrings, which kills hip drive out of the hole. Though I see no mechanism of the hamstrings contributing to knee extension, and in fact, if anything, they work against it. If your glutes muscular buttocks are strong enough though this might be ok due to Lombard's paradox, but it seems having the hamstrings contracting hard is counter to standing up. Well shit, I can't even come up with an argument FOR it.

The hamstring vs. quads works like every other opposing muscle group. The hamstring has real good leverage/a good lever on the pelvis and real poor leverage on the tibia and fibula. The quads have really, really fucking good leverage on the tibia and no leverage on the pelvis (except for rec fem, but fuck rec fem). So when they "oppose" the quad pulls on the tibia, which pulls on the hamstring which pulls on the pelvis. The hamstrings don't counter standing because they simply don't have the leverage to do so and because one side of the pull (the pelvis) is unbalanced.

That seems to be an argument for why we should squat-morning our squats by having the hips move back that way and then forward again. I don't have a convincing argument off the top of my head, but some vague consideration that the hamstring's isometric contraction helps maintain the back angle alongside the erectors, and that squatting in the way described above with knee slide feels like shit and kills my bar speed on heavy squat reps.

112% this. I have seen no one in person that "knee slides" their squat and makes it look good. Almost everyone comes down too upright, bounces into their knees, then kicks their hips back and gets too bent over and it fucks with everything. And it makes bar path look like shit too. Theoretically it may be fine, practically no one rotates their torso around the bar perfectly as their back changes angle to keep the bar in line.

[ChasingCurls69]

ETA: Knee slide is purported to shorten the hamstrings, which kills hip drive out of the hole. Though I see no mechanism of the hamstrings contributing to knee extension, and in fact, if anything, they work against it. If your glutes muscular buttocks are strong enough though this might be ok due to Lombard's paradox, but it seems having the hamstrings contracting hard is counter to standing up. Well shit, I can't even come up with an argument FOR it.

The hamstring vs. quads works like every other opposing muscle group. The hamstring has real good leverage/a good lever on the pelvis and real poor leverage on the tibia and fibula. The quads have really, really fucking good leverage on the tibia and no leverage on the pelvis (except for rec fem, but fuck rec fem). So when they "oppose" the quad pulls on the tibia, which pulls on the hamstring which pulls on the pelvis. The hamstrings don't counter standing because they simply don't have the leverage to do so and because one side of the pull (the pelvis) is unbalanced.

That seems to be an argument for why we should squat-morning our squats by having the hips move back that way and then forward again. I don't have a convincing argument off the top of my head, but some vague consideration that the hamstring's isometric contraction helps maintain the back angle alongside the erectors, and that squatting in the way described above with knee slide feels like shit and kills my bar speed on heavy squat reps.

112% this. I have seen no one in person that "knee slides" their squat and makes it look good. Almost everyone comes down too upright, bounces into their knees, then kicks their hips back and gets too bent over and it fucks with everything. And it makes bar path look like shit too. Theoretically it may be fine, practically no one rotates their torso around the bar perfectly as their back changes angle to keep the bar in line.

The wildest thing is watching olympic lifters basically see-saw their squats up while making 50000 posts about how they squat high bar and super upright for specificity.

[OCG]

Maybe not the best example, but close enough.



Yes, gif is for ants.

[damufunman]

Good points, @OCG and @ChasingCurls69. Though it seems like you're arguing against knees sliding back, right? I think the OP was referring to knees sliding forward during a low bar squat and why is that a problem? @mgil could you clarify?

[mgil]

Yeah, end of ROM knee slide forward that’s a result in change of angle at the ankle as opposed to the knees sliding backwards when the hips are also sliding backwards on the way up. The latter seems to be from weak quads.

[Wilhelm]

112% this. I have seen no one in person that "knee slides" their squat and makes it look good. Almost everyone comes down too upright, bounces into their knees, then kicks their hips back and gets too bent over and it fucks with everything. And it makes bar path look like shit too. Theoretically it may be fine, practically no one rotates their torso around the bar perfectly as their back changes angle to keep the bar in line.

A lot of my squats are now really good with knee position staying pretty close to fixed in at the bottom.
This actually surprised me because it happened by working on other parts of the movement, namely upper back and bar path.
I have a pretty upright back angle, but i don't always hit it right still.
I don't think i have any sessions when at least a few reps are less than ideal.
Some sessions more than others. I'm trying to get it more ironed out while i'm doing mostly lighter weights at the start on doing MM.

When i do get a good bit of knee travel in the bottom, i get that "bouncing into" my knees you describe, and that brings the back angle down further and that affects bar path out of the hole.
I think maybe it's the bouncing on my legs that causes the knee travel.
It's still hard to decode everything when i watch back.
Maybe reaching forward more than sitting down.

I have widened my stance a little, and i think that has helped keep my torso from bouncing against my legs as much.
And i try "sit my butt down more" as a cue.
This is where the answer lies for me, afaict.

[Cellist]

The (oversimplified) idea is that the knees reach their final forward position at 1/3 to halfway down and the rest of the descent is accounted for by the hips. The problem comes if this is accomplished by compromising tightness of the torso.

Knee slide + tight toro is fine:

[KyleSchuant]

Is there a solid argument that knee slide creates a lack of efficiency in the squat?

Well, the bar speed certainly slows down when they good morning it. But really it just looks ugly. Unless it's a third at a meet, if it looks ugly it's probably wrong.

[Wilhelm]

The (oversimplified) idea is that the knees reach their final forward position at 1/3 to halfway down and the rest of the descent is accounted for by the hips. The problem comes if this is accomplished by compromising tightness of the torso.

Knee slide + tight toro is fine:

I think that's right.
And it's not entirely rare that i will get loose at the bottom trying to do it right.
Not super often though.

Sometimes, almost inexplicably, i will have nearly "perfect" knee position.
But i maybe more often get a similar bit of travel as CWS there on that first, squat and can still not get the tilting forward of the torso into GM.
My knees and hips do come back and then up, i guess.
This for me is a decent rep. I think avoiding the worst is what i can attain on an overal average if i'm doing well.

[mbasic]

The wildest thing is watching olympic lifters basically see-saw their squats up while making 50000 posts about how they squat high bar and super upright for specificity.

Yes, I used to think this too.
Sure, some people not self-aware and egos kick in, I get it.
And most people doing what you are describing are probably not good lifters.....or aren't good squatters...or don't have the body type for being a good upright squatter. Good luck to them in their Olympic lifting and back squatting.

But if you think about it....

You might see that (GM+seesaw) on limit sets/reps or 95%+1RMs.
....think instagram, etc.... "nEw HeAvY FrIDaY TRaInInG!! ViDeo", etc

But if the bulk of their squat/volume training is in 70-85% range, which is common place, yes 90-95% of the backsquats they perform over the course of a their training cycle WILL BE more upright tidy looking squats, and these loads are probably closer to their max clean&jerk weights. These are the squats you'll normally NOT see on social media, or NOT pay attention to in a gym setting.

[ChasingCurls69]

Good points, @OCG and @ChasingCurls69. Though it seems like you're arguing against knees sliding back, right? I think the OP was referring to knees sliding forward during a low bar squat and why is that a problem? @mgil could you clarify?

Because they happen together and I think the knees sliding forward causes them to slide back on the way up.

[mgil]

Good points, @OCG and @ChasingCurls69. Though it seems like you're arguing against knees sliding back, right? I think the OP was referring to knees sliding forward during a low bar squat and why is that a problem? @mgil could you clarify?

Because they happen together and I think the knees sliding forward causes them to slide back on the way up.

Looking at the CWS video, the knees do slide fore and aft at the very bottom, but the hips are going pretty much vertical. Mainly because he’s changing angle at the ankle. The ugly knee slide is when they start coming back and the hips do also.

Also, reference @Austin’s post in the other thread about knee slide.

[asdf]

The wildest thing is watching olympic lifters basically see-saw their squats up while making 50000 posts about how they squat high bar and super upright for specificity.

Maybe not the best example, but close enough.

Here's a video of Clarence standing up a 215kg clean. Looks to me like his mechanics are exactly the same as with his high-bar back squat -- so yeah, specificity. His back angle doesn't change *quite* as much on the front squat, but it's pretty close. And in neither squat is his back angle anywhere near what Rip would advocate for a low-bar back squat.

[ChasingCurls69]

@asdf in the back squat you can see the see-saw thing happen a bit but not particularly bad, and I'm not really seeing it at all for the front squats.

CWS in that video has a bit a knee-slide, but yeah his knees don't shift back right away either. I'd argue if the knees slide forward, but stay in that position coming out of the bottom so the hips don't shift back/back angle doesn't dramatically change, then it doesn't matter. I also think that's less common than the usual results of knees coming back too early as a consequence of knee slide.