foweyman wrote:It is not a properly controlled experiment. People run with different form when they remove their shoes (didn't save the ref.), mostly to reduce the increase in impact that occurs without the cushion of shoes. This change in form could easily cause changes in the measured parameters that were attributed to the shoes. Before thay can ascribe the observed differences to the shoes, the experimenters would have to make sure that the subjects run with the same form when barefoot and shod.
I didn't get the idea they were trying to control form or were ignorant of form as a variable. Indeed the point seems to be that the way that shoes change your form increases the impact forces beyond what the shoes are able to absorb. What exactly would be the point of a study that is controlled in the way you suggest? To test the prediction that it would be superfluous (save perhaps for fashion) to run in shoes that interact with the feet in the exact same way that the ground does?
I'm guessing that the best way to minimize impacts is to use barefoot form while wearing good shoes. It takes some kinesthetic awareness, but with practice and concentration it is reasonably obtainable.
I basically agree. I for one experience a lot less knee impact running barefoot-style in my shoes than running the heel-striking way that the shoes are designed for. However, except up steep hills, it's impossible to run exactly the same way in running shoes as barefoot, because the heel is elevated too high by the shoes. You have to understride and/or increase your forward lean to compensate if you don't want to either strain your calves (the calves can't extend enough to get a stretch-induced elastic recoil, so you have to flex them to absorb the landing force) or significantly weight your heels, which is the main source of the knee impact, not to mention creating potentially excessive pronation compared with a ball-of-foot landing. If you have to subvert the design of your shoe, or if it needs features like pronation control to compensate for the effects of its other features like an elevated and padded heel, then there's something wrong with that design, even if you can subvert it successfully, because you shouldn't have to subvert it at all, especially when you pay so much for it. Though by "good shoes" maybe you are talking about a more minimalist style that more easily permits barefoot-style technique, unlike mine and those of most runners. The only reason I run in my shoes this way anymore is because (a) I already paid for my shoes before I knew the design is crap, so I use them when the weather is too cold for bare feet or Vibram Five Fingers (still looking for a more permanent solution to this), and (b) I'm still transitioning to barefoot/VFF running and (less and less frequently and/or only at increasingly longer distances) use the shoes to give my developing feet and calves a break.
There is also a good bit of variation in the cushioning ability of "typical running footwear". Without controlling and specifying the model(s) it is difficult to ascribe the effects to running shoes in general.
They <a href="http://www.pmrjournal.org/article/S1934-1482%2809%2901367-7/fulltext">did</a> specify the model:
"...the control shoe used in this study was the Brooks Adrenaline (Brooks, Bothell, WA), selected for its neutral classification and design characteristics typical of most running footwear."
There is also no biomechanical reasoning provided for the conclusion that "These increases are likely caused in large part by an elevated heel and increased material under the medial arch, both characteristic of today's running shoes."
You're critiquing a summary; you should probably read the real article. Yeah, they didn't get too much into the biomechanics, but they didn't completely ignore the angle either.