Question for Coach Steve Hill

[Dwayne_KONG_Wint]

Hi Steve,

I've been trying to understand the difference in the physics of how the foot interacts with a flat shoe versus a heeled shoe in lifting. I'm wondering if "midfoot" is different with a heel because I've noticed that I can truly feel "midfoot" with a flatter shoe during a squat whereas with a higher heeled shoe, the assuredness of "midfoot" is much less.

My mechanics skills are very rusty (graduated BSEE in 2002) and I wasn't that great with it when those skills were fresh 15 years ago. I understand that you are a mechanics expert. So, I was wondering if you could discuss the differences in how the forces are distributed if there is a difference at all. Also, if there is no difference, could you explain why. I would greatly appreciate it.

Dwayne

[Steve Hill]

It's an interesting question. Yes, mechanically, it there would be difference. The question is "How much?" From a perspective of simply looking at the effective length of the foot, the answer depends on A) size of the foot (length) and B) how much lift the heel gives. As an example, a 3/4" heel is going to have a much larger effect on a person with a size 4 foot than a size 14.

I need to think about it before I say more.

[Dwayne_KONG_Wint]

I think it would depend on the magnitude of the force from the foot into the wedge. OK. So lets use me to make the assumptions:
1. Large foot (size 12)
2. typical heel ( 3/4 inch)
3. Little to no give (ideally)
4. Force on the foot to the wedge: my weight (260 lbs) + 500 lbs


My mech fu sucks. I asked a couple new hires who have Mech E degrees here but I didn't give them the context; so their answers, while helpful, were not useful. You are my only hope.

[Tom Campitelli]

You are my only hope.

Where's Wolf? This is very Star Wars-esque.

[wk105]

The level of shoe science in this thread makes me think it's the right place for this question:

Is a heeled shoe mechanically advantageous in the press? Or, assuming a non-compressible sole, is a flat shoe just as good?

Thanks.

[Steve Hill]

Where's Wolf? This is very Star Wars-esque.

It's as if millions of voices suddenly cried out in terror, and were suddenly silenced.

[Steve Hill]

I'll be working on my thoughts on all this tonight. Understand that Rip has some questions in to me on a different topic and so you guys go to the back of the line.

[Steve Hill]

OK,

First off, sorry for the delay. I've been slammed at work since I got back from the San Antonio Fire Department seminar. Off we go.

First, my initial thoughts still apply - depends on foot size and amount of heel. BUT, in a large foot / 3/4" heel, the maths don't work out for much displacement for what feels like the "mid-foot." When the heel lifts it moves the ankle joint SLIGHTLY forward ( and up, for those who want me to state the obvious) - in all, back of the envelope, about 1/8". and that's it. That means that the mid foot might (dependent on the construction of the shoe) move forward as much. HOWEVER, it won't change relative to the toes or the heel because the segment length is still the same. So the answer to your question is "not really much at all." So why do people feel (and occasionally see WRT amount of weight lifted) when using a heeled shoe? Well, off the top of my head:

1) Lifting the heel means that there is a slightly shorter calf muscle, so there may be less tension initially in the gastroc / achilles / plantar fascia system, giving the feel of less tightness / stability (or perception)
2) It also moves the knee slightly forward during the lift (though this should reduce or eliminate the issue in #1), but it may contribute to the perception.
3) You are, as you noted, standing on an inclined plane. Now, as far as sliding down the sole of the show, well, that's what tight laces and a metatarsal strap are for. The carcass of the shoe is supposed to handle this, so I suppose if your laces / strap are lose, this could also contribute to a feeling of instability.

But the lift of the heel itself does not move the midfoot in relation to the rest of the foot - the segment length of the foot is the same - or the barbell, since you place the bar over the midfoot, no matter where it is. The foot, in a shoe with a raised heel, is very slightly shorter in length when looked at in reference to the contact patch on the floor, but I don't see 1/8" making all that much different. I suggest that you just need a shoe with a little less lift.

[Andres Onu]

Thinking of it in an extreme, suppose you squatted in a 6" heeled shoe.

When with the bar over the mid foot and the mid foot remaining in the same place relative to the rest of the foot as you stated AND the carcass of the shoe doing its job; you'd still feel a lot more pressure toward your toes. But perhaps this is a limitation of the shoe marital being able to spread the weight evenly in such a case.

[Dwayne_KONG_Wint]

Thanks Steve.

Yep, I lace and metatarsal strap tightly. I do have a narrow foot though and my shoes are wider.

I ordered some no heel and lower heel shoes. The no heels come this weekend. Delivery date on the lower heel is still on hold although I know it has shipped.

Maybe my perception is just very sensitive at this point.