Hip Flexors for Squatting...

Training Powerlifting
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[quote]clonewars2000 wrote:
wufwugy wrote:
i assume that OL shoes have a raised heel to help lifters get deeper in the catch. i also assume that the raised heel will negatively affect posterior chain recruitment. i dunno though; just speculating.

If you have a raised heel and you increase your shin angle, you are stretching your quads right? so wouldn’t you be using more of your posterior chain. Didn’t one thread say that the post. chain is 70% of the squat? I assume that by using a heel lift like the Oly. shoe would recruit more post. chain. And since these guys have more than adequate flexibility, it wouldn’t affect their quads as much and they could recruit more glute. Thoughts??? [/quote]

you’re probably thinking of Joe DeFranco’s assessment that the vertical jump is 70% p-chain. the prime muscles in full/oly squats are quads and glutes.

i dont see how raised heels will stretch the quads. a few seconds ago i sat in a full squat and did calf raises and experienced what seemed to be zero quad lengthening. i think that experiment applies to your question.

even then, if the quads were lengthened i dont think that specifically means the p-chain is more recruited. actually, that would make me think the quads are more recruited.

the reason i had for stating the heel lifts might be deleterious for p-chain involvement is because, when lifting, recruitment of the p-chain is influenced by ones “focus” on driving through their heels. if OL shoes helps quad recruitment then i’d hypethesize that we should all be able to squat more with 25 pound plates under our heels. i dont think that’s how it is, though, i’ve never focused on those kinds of squats.

but obviously, OLers get enought p-chain recruitment with their shoes so… i still think they’re for depth and catching purposes.

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[quote]wufwugy wrote:
ckeller14 wrote:
wufwugy wrote:
why does the knee joint hafta extend when the lower leg returns to perpendicular to the floor due to decrease in ankle flexion?

im still trying to understand this peculiar supposition???

If not you’ll fall on your ass. Either that or have to increase flexion of your trunk to compensate.

or come off your heels and onto your toes. still doesn’t make sense to me how the soleus can be considered a knee extensor, but i can understand how in certain movements the soleus and quads must move at the same time…that doesn’t mean one can call the soleus a knee extensor.[/quote]

I understand the difficulty in figuring this one out; I didn’t buy it at first either. It simply is a different parardigm from the one we’ve been conditioned to accept.

The traditional anatomy approach has given us muscle actions based on what the body does lying on a slab either prone or supine. So, lying prone or supine on a slab, the quads are knee extensors, agreed? Now in the same position, how do we stretch the soleus? Dorsiflex the ankle and for more of a stretch, bend the knee. Right? But what if the foot is fixed, say to the floor? The foot can no longer move freely in space, so in order to stretch the soleus you still have to dorsiflex the ankle, but you also have to bend the knee, as in your traditional soleus stretch. So, in order to turn that soleus stretch into a gastroc stretch, what do you do? Straighten the knee because the gastroc crosses the knee joint which you mentioned before.

So, in the ascent of the squat as the soleus contracts it plantarflexes the foot. Since the foot is in a fixed position–in contact with the floor–the shin returns to perpendicular to the floor and extends the knee. If the foot were not in contact with the floor the action of the soleus would plantarflex the foot and the shin wouldn’t move, like a seated calf raise.

Can you see it?

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[quote]Krollmonster wrote:

or come off your heels and onto your toes. still doesn’t make sense to me how the soleus can be considered a knee extensor, but i can understand how in certain movements the soleus and quads must move at the same time…that doesn’t mean one can call the soleus a knee extensor.
I agree.

I have a question. If the soleus and quads share that relationship, would squatting in olympic lifting shoes (which have a higher heel) lend itself to an advantage in squatting due to the greater possibility of contracting the soleus on the concentric part of the rep?

[/quote]

Interesting question Krollmonster.

I don’t think that originally the developers of the olympic lifting shoe were concerned about the relationship of the soleus to the quad. The heel is designed to help the lifter keep the torso perpindicular to the ground which is of utmost importance in the o-lifts. The heel also allows the lifter to keep the “arch” in his low back–we talked about this earlier–so it can be seen as a mechanical compensation for a lifter’s poor flexibility.

However, I think you may be right. With the heel or without the heel, the joint angle of the ankle is relatively the same. However, with the heel, the torso is more upright, increasing the load on the soleus (and the quadriceps), therefore increasing the stretch on it (as opposed to a flat soled shoe where the load tends to be shifted to the glutes and hams). If there is a greater stretch on a muscle, it stands to reason that there would be a greater contraction of that muscle.

So, in my humble opinion, the elevated heel on a weightlifting shoe increases the role of the soleus in knee extension.

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i think i see what you’re saying i just dont see how because of that the soleus can be considered a knee extensor. AFAIK, the soleus doesn’t cross the knee joint (only gastroc) and if it did, that would make it a knee flexor. saying that the soleus is a knee extensor is like saying a forearm muscle is an elbow extensor.

if the soleus was a knee extensor it would be evident during leg extensions, but it’s not. although, i can see how the soleus is a “knee extensor” during the squat because without simultaneous contraction of soleus and quads the squat fails. but that hardly means that the soleus can be considered a knee extensor just like the quads are.

are you saying that because the soleus is not active when the knee is locked that it’s somehow a knee extensor because the bent joint makes it so?

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The psoas has two roles in the concentric part of the squat: (1) to help the spinal erectors counteract the tendency for the pelvis to tilt backwards, and (2) to make sure you do not fall backwards.

In more detail:
The main drivers of the squat are the quadriceps which extends the knee joint, and the hamstrings and gluteus maximus which extend the hip joint. Above the hip joint is the joint of the lumbar spine (lower back). Above there, there is a heavy weight pressing downwards. The hip joint itself is fixed or moving upwards. Contraction of the hamstrings and gluteus maximus tends to cause a backwards pelvic tilt (they are both attached to the pelvis) which must be counteracted to avoid the lumbar spine to go into flexion.

This is done by the spinal erectors, but also by the psoas which is attached to the spine and pulls it forwards. This may be particularly important in the bottom position of a deep squat, where for most people there is some flexion in the lumbar spine, making the spinal erectors stretched and therefore less strong, while the psoas is in a shortened, strong form in this position. In this way the psoas makes the lower back more rigid, so that power can be transferred efficiently upwards to move the weight, instead of being absorbed by a wobbly lower back. This explains function (1).

To focus on function (2), assume the lumbar spine is adequately stabilized (i.e. the lower back is rigid). Now hip extension will tend to move your torso backwards. That is, it increases the angle (all angles measured in front of the body) between your thigh and your torso. For a given angle between ground and thigh, this will increase the angle between your torso and the floor, i.e. tending to make you fall backwards. Now, suppose the psoas exerted no force in this situation.

You could still avoid falling backwards (i.e. an excessively large angle between floor and torso) by balancing the amount of knee extension (which decreases the, still frontal, angle between floor and thigh) with hip extension (which increases the angle between thigh and torso). That is, you would make sure to lean sufficiently forwards. The problem with this is that since leaning forwards is the only thing you can do to make sure you do not fall backwards, you most likely have to overcompensate a bit, to make sure you stay well outside the angle where you would fall backwards.

Now introduce the psoas. It connects the thigh and torso (across hip and lumbar spine joints), and therefore its contraction prevents you from falling backwards. By using the psoas and not only gravity to prevent you from falling backwards, you have more freedom to adjust the position of your torso and the relative speed of knee extension and hip extension in the way that creates most power. Specifically, you can sit more upright, which reduces the length of the upper body lever and stretches your glutes and hamstrings less.

I hope this helps, if anyone still reads this thread.