Appeared in: Podiatry Today
By: Kevin A. Kirby, DPM
At the beginning of my freshman cross-country season for the University of California (UC)-Davis Aggies, our coach provided all of the runners on the team a pair of new running shoes for us to train in for the 1975 cross-country season. The running shoe in question, the Brooks Villanova, much to our surprise, was very different from the harder rubber-midsoled running shoes that we had trained in previously. The Villanova seemed to be more cushioned, with greater “rebound” in the sole, than any other shoe in which we had ever run. The extra comfort and rebound included within the cushiony midsole made me decide, at an early age, running 70 or more miles every week, that “cushioning was king” when it came to running shoes.
At the time, little did I know the reason this Brooks shoe felt so different to run in was that it was the first running shoe to include ethylene vinyl acetate (EVA), a newly developed material, in the midsole. EVA is a rubber-like foam material, which contains thousands of tiny gas bubble cells with elastic cell walls. This material has the ability to compress a relatively large amount and then spring back to its original shape upon loading and unloading of the midsole. This subsequently returns energy to the running stride. Since the time I first ran in the EVA-cushioned Villanova shoe 44 years ago, the extra cushioning within the shoe was definitely right for me. I loved the feel of running in this particular cushioned shoe.
Ethylene vinyl acetate has been the favored midsole cushioning material for running shoes over the past four decades. Nine years ago, however, thick and cushioned midsole running shoes were claimed to be “harmful” by many “running shoe experts” due to the short-lived barefoot/minimalist running shoe fad that swept the industry from 2010 to 2015. At the peak of this fad, many running shoe companies jumped aboard the minimalist bandwagon and started to produce thinner-soled, less-cushioned running shoes. However, at approximately the same time, seemingly out of nowhere, a small startup company, Hoka One One, was going in the opposite design direction. This company was building the first thick-soled, super-cushioned “maximalist” running shoe.
The shoe company Hoka One One (Hoka) was started in 2009 by two Frenchmen, Nicolas Mermoud and Jean-Luc Diard, with the wild belief that they could produce a better running shoe with more cushion. As accomplished adventure athletes, Mermoud and Diard decided to develop a “fat-tire” running shoe for mountain running that provides cushioning over the running trails much in the same way that fat-tire bikes provide cushioning over mountain biking trails.
The result was the first Hoka running shoe, which had over an inch of midsole material under the rearfoot and forefoot, but was no heavier than traditional running shoes. Interestingly, the thick-soled, maximalist Hoka running shoe started to hit the marketplace at the height of the minimalist running shoe fad, which had, as its shoe “darling,” the ill-fated, five-toed Vibram FiveFinger shoe. Even though the Hoka running shoes were initially derided by many runners and running shoe companies as looking like “clown shoes,” Hoka has now become an extremely popular brand. Many major running shoe companies are now making thicker-soled, cushioned maximalist shoes to compete with the Hoka model.
Even though the thicker-soled, mega-cushioned Hoka is not for everyone, its widespread use in northern California among runners, walkers and workers who stand and walk on hard surfaces throughout the day is quite remarkable. Like I first discovered over four decades ago when I ran in the Brooks Villanova, having extra midsole cushioning in a running shoe seems to make a definite difference in comfort for many individuals. This applies not only to running but also walking and other daily weight-bearing activities. Maybe those who wear maximalist running shoes for comfort are telling podiatrists that, as far as they are concerned, cushioning is still king.
Dr. Kirby is an Adjunct Associate Professor within the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University in Oakland, Calif. He is in private practice in Sacramento, Calif.