I think part of this also has do with those who learned running through puberty. They dp not have to be runners from track or cross country but if they played sports with active running like football, soccer, basketball etc how these athletes are tuned to their running gait will be different than those who ran as toddlers and did no running sports through puberty till adult life. Much the same as adult onset swimmers who can almost never reach the same swim technique as youth long swim fish. Different groups will have different reaction to shoes because of what natural wiring they have developed for running (or not). Everyone seems to treat running like a technique-less sport, but that's not totally the case.

I'm not familiar with what exactly a yoga ball is, but if it is anything like a stability ball I think you're analogy is off point. Imagine if you held the stability ball tightly against your chest and ran into another person, they go flying and you stay put. That's what seems to be missing here, in the padded shoe the foot is held firmly against the padding and they move together against the ground. If the ground and foot were both moving toward the padding and striking at the same time it would be different, but that is not what happens.

This seems like a case of applying science without the use of common sense. Here is an easy test, punch the pavement with a closed fist; then strap a shoe over that same fist and punch the pavement that way. Did you notice any decrease in force applied to your hand and arm?

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Punch a brick wall with your bare fist then punch the wall wearing a boxing glove.

But that isn't the same as running.

You are running along the surface not stamping on it trying to hit it hard.

You're spot on that experience is important ... That adds an interesting element to this type of research. Trying to account for experience is not easy because everyone's experience is rather unique.

What you are missing is that a good runner does not punch the ground with his foot...the good runner compresses his entire body from the pelvis down to the feet stores energy and springs off.

The better analogy would be to stand 18 inches from a wall and fall forward and "land" on your open palm, and then "push off" like you are doing a push up. You should be able to do this against a brick wall without hurting your hands, Granted, all your weight on pavement is "harder" but the leg are also stronger and relatively more springy....we certainly don't punch the ground with our feet while running.... I THINK that's 95% of the point of this thread in the first place.

True, but when you lean into the wall you are only applying a fraction of your body weight to your palms, when you strike the ground running you are applying a multiple of your body weight each time, right? If that's true, then the fact that your body does a good job absorbing the forces doesn't change the fact that there are quite a lot of forces still at the foot. And to be honest, my running does feel like my foot is punching the ground with every stride. That might be wrong, and I would be very happy if there was a quick fix that would let me break this barrier of ~17:50 5k, but it seems unlikely. Every foot strike has to change your body's momentum from down to up in a fraction of a second; I'm not sure how you could do that without applying explosive forces through your foot to the ground.

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I don't recall any of these studies having anywhere near enough samples to do subgroup analysis. It may make for good/useful future hypotheses, but won't have anywhere near the stat significance (unless the effect is gigantic).

But I certainly hear you. Different runners will want different shoes. The same runner will want different shoes for different activities, or for different times in his/her life/training. It's madness! :)

* And I still find Dan's old article about Hokas being the second coming of Christ pretty hilarious...

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The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock

One thing that I found interesting about the heavily cushioned shoes relates to an observation of my daughter's experience. My oldest child has ms. She was never a runner as a youngster and has become a runner over the past few years ......

Here is a father's brag video where the ms society followed her around for a day and filmed us going for a run ....
https://www.youtube.com/watch?v=iGP5qV4C85c


When she started running using conventional shoes she got a lot of numbness in her feet. I bought her some Hokas and that problem went away. As she trained more and became a little smoother with her running, she was able to ditch the hokas (although she still likes them and wants a pair of their trail shoes) and move to more neutral/minimalist shoes (which is what both her sister and I usually wear) and no longer has the same issues.

Makes me wonder if the extra cushioning acted as a placebo or whether the improvement in her running form made a difference.

Tulkas wrote:

True, but when you lean into the wall you are only applying a fraction of your body weight to your palms, when you strike the ground running you are applying a multiple of your body weight each time, right? If that's true, then the fact that your body does a good job absorbing the forces doesn't change the fact that there are quite a lot of forces still at the foot. And to be honest, my running does feel like my foot is punching the ground with every stride. That might be wrong, and I would be very happy if there was a quick fix that would let me break this barrier of ~17:50 5k, but it seems unlikely. Every foot strike has to change your body's momentum from down to up in a fraction of a second; I'm not sure how you could do that without applying explosive forces through your foot to the ground.

I know what you are saying but this is only a strength of arms vs strength of legs issue as to why you would punch the ground if you had to use your arms. One can also do "clap" pushups where you "lift off the ground" with each pushup...arms just can't do this with slow twitch muscle fiber but it can be done.

If you watch Usein Bolt run, he's not punching the ground by any means or a top 110m high hurdler..Colin Jackson's 12.91 and Renaldo Nehmiah's 12.93 world records come to mind. No punching the ground at all, but huge stride length and ground forces at play. The fastest runners won't punch the ground. Also watch Mo Farah's acceleration finishing the London Olympic 5000m. Fast forward to race clock 12:47 and you'll get to watch what a 53 second closing lap (as part of a sub 4 closing mile) looks like:

https://www.youtube.com/watch?v=C93qwVmBseE

Allan, my "guess" is that there was something going on like when someone first starts weight training. When they first start, they are not able to push a lot of weight but rapidly in a span of less than 2 weeks there are dramatic gains not because of physiological adaptations, but because the brain learned how to fire the muscles in unison and deliver an "impulse" force effort.

So my hypothesis is that with MS and having less forceful muscle contractions to begin with due to the electrical "leakage" from nerve demylination, her brain needed to learn how to activate the muscles for sufficiently forceful contractions to run. The Hokas, would have helped reduce the eccentric forces, in other words she would not need to lengthen the muscles in the quads and the shins as forcefully and could slam down and let the shoe do some of that....but as her brain learned how to contract those muscles to deal with the impact, she has been able to more to less supportive shoes now that her body can do the work....to some degree, this is what bodies of able bodied folks won't do when the legs are tired/fried.....so no wonder Hokas feel good off the bike when our muscle contraction forces are low.

What do you think....you were there as she went through the learning process for running. It's not as natural an activity as most people think. We grew up as kids as runners and learned how to do it (unlike our pathetic swimming....).

I don't know, looks like he's hitting the ground pretty explosively with every stride. It would be interesting to see what the peak impact forces are for him at that pace.

However, I don't think maximal padded shoes are intended for world class runners, at those speeds your stride is naturally different. The average plodder will have far more vertical oscillation and, one would think, a more punchy stride. Also the maximal shoes are marketed to heavier runners, if force is multiplied upon impacting the ground then they would experience significantly higher forces each stride.

But that is a bit off track I think, I was mostly chiming in on the idea from the original post that maximal shoes don't result in reduced impact forces. I still think that's absurd and doesn't pass the common sense test. If more padding doesn't result in lower impact forces then why don't we wear a racing flat for all long runs and races? I've worn my ultra light flats for a half marathon race before and my legs were destroyed, I've literally recovered from full marathons quicker than I came back from that one. I have actually never even tried on a pair of maximal shoes (I like my Energy Boosts too much to bother with something else), but I have heard from numerous people the same story that these shoes allow them to run again without pain. If they aren't cushioning the impact any more than any other shoe then it has some impressive placebo qualities!

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All i'm trying to point out with my analogy is that the force the ground exerts on the shoe is (within a very small error) transmitted to the foot. I'm not arguing that the force is the same as it would be without the shoe. I'm only saying that if you're measuring the force at the ground-shoe interface you also know what's happening shoe-to-foot.

And yes, those things are simultaneously possible. It seems to be a difficult concept.