Barefoot, minimal, drop, stack … we sort out terminology confusion

As the barefoot/minimal movement shifts from trend to acceptance, it is becoming just one of many choices for consumers. Adventure Network + Total Fitness Network took a look at a couple of new studies on the now-mainstream trend as well as some background in a story on. Click here to read that story, one of many we will be tackling to keep you well informed.

“The trend looks as if it’s lasting,” Seth Cobb, vice president and general manager at Merrell, told AN+TFN recently. Merrell is one brand that has indeed revamped its entire line to be less-is-more. “There is a customer benefit.”

As more consumers recognize the benefits of barefoot or minimalist shoes – and mainstream acceptance occurs — one dilemma starts to emerge: There is no one definition of what makes a barefoot shoe actually “barefoot “or a minimal shoe really “minimal;” rather we see blurring and even a bit of BS from some companies, all leading to customer confusion. With differences important to note in your choices, we’re going to help sort this out for you. Some widely and mostly accepted parameters exist with two variables typically coming into play in the discussion: Drop, and stack height.

• Drop is reported in millimeters and is the difference between heel thickness to toe thickness – more “drop” means your heel is more raised. Thus, a 15-mm heel and an 11-mm forefoot sole measurement is a 4-mm drop. However, a 9-mm heel and a 5-mm forefoot is also a 4 mm drop. And of course a 4, 11 or even 15mm reading in BOTH heel and forefoot would then be “zero drop.” The thing to remember is that zero drop does not mean zero cushioning or flat on the ground and thus “barefoot,” since you can have some cushioning layer running the full length of the shoe while maintaining a 0-mm difference.

• Stack height is of course the measurement under the foot, i.e. the “stack” of the cush. As the product arena in the barefoot/minimal segment has expanded, one can find everything from zero drop to pretty significant drop with all kinds of stack/cush. As noted, above, you can easily find 15-22mm stacks underfoot that are still zero drop (what has been traditional shoes are often 20-25mm underfoot, while of course racing flats and cross-country spikes were the minimal shoes of yesteryear).

In the end – with wide variations – “barefoot” seems to have come to mean little or nothing under foot (up to about 4mm) while maintaining zero drop, and “minimal” seems to be interpreted as adding a bit more overall drop – perhaps up to 4-6 mm difference from heel to toe – while the stack is frankly still widely debated. Some companies told Adventure Network® recently that it mean as little as 4-6 mm underfoot, while some have introduced shoes at recent trade shows that were as much as 18 mm at some point underfoot yet were still called was minimal.

“When you start to get into the minimalism concept, things start to get fuzzier,” Merrell’s Cobb told AN+TFN.

Merrell, with its first introductions barely a year ago, has revamped its entire line to include only barefoot or minimal pieces. Newcomer Altra touts more stack overall but always a zero drop. Vibram’s Five Fingers has introduced slightly more protection and support, especially in winter styles, but maintains the barefoot mantra of 4 mm or less in stack and zero drop.  Others taking on the market strongly include Saucony and New Balance (the company’s Minimus shoes and accompanying chart were used in our image example for this article), as well as a slew of smaller companies looking to grab a piece of the barefoot/minimal pie. AN+TFN is going to take another look at new and coming products in a future piece.

All are touting the benefit of encouraging a forefoot strike, although exercise physiologists over the years have often talked of a midfoot strike being perhaps ideal, with forefoot striking only occurring in sprinting, racing or faster running overall. New on the market are a few models from Skechers that actually are said to promote the midfoot strike due to a slightly higher stack in the midfoot (for example, 15 mm in the heel, with 18 mm in the midfoot and 11 mm in the forefoot). It’s too early to draw conclusions on comfort, viability or safety and no studies have been done as of yet.

As a key development in running, walking and training, AN+TFN will continue to bring news about trends, studies and products in this area.

–Therese Iknoian

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The “Coach,” Therese Iknoian, has her Master’s degree in kinesiology with an emphasis in exercise physiology and is an American College of Sports Medicine-certified instructor. To read more about Therese’s coaching, outdoor and fitness background, click here.