Copyright XKCD, by Randall Munroe.

Seeing With Your Feet

Do barefoot shoes reduce injuries or create them? The data is mixed. Here are 5 principles in support of a minimal footwear.

Barefoot shoes have been mocked as a paleo fad, with detractors turned off by toe-shoe-wearing non-conformists. But the basic idea behind a minimalist shoe is sound: you can have all the benefits of going barefoot — walking the way we evolved to walk — while protecting your feet from dirty streets and broken glass.

Still, it’s hard to cut through the marketing bias for any product, including minimalist shoes, and the science behind their efficacy is murky.

I switched from thick-cushioned to thin-soled barefoot shoes a few years ago and never looked back. My first pair lasted longer than any pair of shoes I’ve ever owned. My knee and ankle pain went away, and I could feel my feet, calves, and joints getting stronger just from walking.

With that said, my experience barefoot running has been more mixed. I’ve developed injuries, and gotten over them. Without delving into whether or not running is a natural activity, I will just deal with principles to support the use of minimalist shoes here.

The Five Principles of Minimalist Shoes

1. It’s not all about the shoes.

Michael Jordan didn’t win six NBA championships because he wore Air Jordans. Don’t be fooled by marketing. Wearing fancy shoes won’t make you an all-star athlete, or cure all of your injuries.

You should be deeply suspicious when shoe companies start talking about “shock-absorbing midsoles, contoured foot bed, superior arch support, and deep heel cups that stabilize and support feet.”

Still, shoes matter. Feet are the body’s foundation; if we screw them up, a lot can go wrong. Just like the bed you sleep in, or the person you marry, you spend a lot of time with your shoes. It’s better to have one really good pair than many mediocre pairs. Be a minimalist when it comes to minimalist shoes.

Minimalist shoes illustrate the principle of addition by subtraction, or “the art of adding by taking away.” While other shoes try to sell you on fancy features, like Reebok’s shock-absorbing “pumps,” minimalist shoes strip away all that is unnecessary, and let your foot do what it’s built to do.

2. Injuries from walking, running, and bad posture are lagging indicators — they only show up after years of misuse.

Paul Ingraham, a writer for PainScience.com, did a meta-study of sorts — looking at all the studies on barefoot running. He concludes that we really don’t know whether they lead to more injuries or fewer.

One well-designed study found no statistically significant difference in injury rates comparing barefoot runners with those who stuck with regular cushioned running shoes. A second study found that runners who transitioned to barefoot shoes had more injuries after 26 weeks.

These trials are misleading, though.

First, minimalist shoes are a lifestyle change that extends beyond exercise. The running world is not typical, and long-distance running is not a particularly natural activity (unless you are an African persistence hunter). Most people spend most of the time on their feet walking, not running. Thick soles and cushioning go against the natural method of walking, honed by millions of years of evolution.

Second, meaningful results cannot be achieved in such a short period of time. Every person is a walking experiment of n = 1, and we won’t know the results until we’re old. In my experiment, I’m going off of first principles, since the data is inconclusive. The main principle behind barefoot shoes is simple: the foot is a marvel of evolution, containing 200,000 nerves and 26 bones. Shoes are a useful technology for some kinds of terrain, and provide essential protection for certain kinds of work.

However, the “protection” shoes offer filters out important tactile feedback from the ground. Cushioned shoes make it so that you don’t notice gradually developing injuries and unnatural walking patterns. It’s the same reason boxers who wear padded gloves suffer more head injuries than MMA fighters who don’t, or why brain damage among NFL players is getting worse the “better” the helmets get.

The world’s oldest known leather shoe. Photo courtesy of Gregory Areshian.

Thick soles and cushioning go against the natural method of walking, honed by millions of years of evolution… The main principle behind barefoot shoes is simple: the foot is a marvel of evolution, containing 200,000 nerves and 26 bones.

3. Your foot nerves help you “see” the ground, like a dolphin “sees” with sonar.

Your foot should be constantly adapting its position to the terrain. Each foot’s nerves are there to “see” the ground like your eyes see light, or your ears hear sound waves. Bio-mechanist Katy Bowman describes it like this:

“There are nerves that interpret the shape of the ground by how the bones in the feet bend at 33 different points (joints). This creates a mental image in the brain (similar to how a dolphin uses sonar to avoid obstacles). Wearing shoes prevents any motion in these joints (except the ankle) and leaves the shoe-wearer “blind” to the environment. This is what makes stiff shoes the worst when it comes to natural development.”

One could rightly point out that sometimes we don’t want or need to know exactly what the terrain is. If we’re walking on craggy rocks or on dirty city streets, it’s nice to have a buffer between the skin and the ground. Therefore, it makes sense to wear a shoe that gives as much tactile feedback as possible while blocking out the unwanted “information.”

4. Better feedback makes your gait more efficient.

Shoes with an elevated heel incline you to land hard on the heel — especially when you run or walk — rather than striking the ground with the or forefoot (ball) or gently with the heel. The cushion prevents immediate pain at the point of contact, but over time the extra force grinds down your joints. This is a less economical way of moving, since the heel strike creates resistance and dissipates momentum. A ball or mid-foot strike makes your foot work like a spring that conserves your energy after each step. There’s actually no such thing as a mid-foot strike, since your ball or heel always makes contact with the ground first. As far as I can tell, the term mid-foot strike is used to indicate a gait that does not exclusively favor either the ball or the heel. It might alternate depending on your pace (faster means more forefoot), or the terrain (downhill means more heel). This makes sense if you consider the mechanics of the foot — a lever on the end of your foot that delicately balances your body as you move horizontally through space/time.

Shoe companies add hard materials in the mid-foot region to absorb the shock from a heel strike. But research shows that running shoes generate 37% higher internal torques on the knee and 54% higher torques in the hip joints.

In an ideal world we might all still be walking around barefoot, but that’s not the only option. Shoes with “zero drop” from heel to toe, and a wide toe box are the next best alternative. When your heel has to go level with your toes, it means more extension of your Achilles tendon. A shoe with positive elevation in the heel means your Achilles tendon is always slightly retracted and thus more prone to injury (think snapping) when fully extended.

A wide toe box eliminates the milder version of Chinese foot binding that happens whenever the tips of the shoes compress your toes together. Splayed toes also help with balance and sensory feedback.

5. The body is antifragile — it grows stronger from stress & disorder.

Nassim Taleb has popularized the word antifragility to denote “things that gain from disorder” (up to a certain point). The human body is the antifragile system par excellence. We thrive on stress in the right quantities. Too much (think falling out of a 3-story building) and you break. Not enough (think couch potato) and you atrophy.

Antifragility is a reason to wear minimalist shoes as much as possible, but not freak out when you have to wear uncomfortable shoes for some special occasion.

Studies on barefoot shoes focus on the impact or shock generated by the downward force of the leg against the ground. Some studies show that barefoot shoes increase impact while others find that they decrease impact. Taleb’s antifragility framework suggests that this is the wrong focus. We want stress in certain areas — bones, for example, get stronger under compression — while other kinds of stress like hip and ankle torque go against a natural walking movement and should be avoided.

The worst thing you can do is try to insulate your feet from any discomfort.

Taleb writes:

Tonight I will be meeting friends in a restaurant (tavernas have existed for at least 25 centuries). I will be walking there wearing shoes hardly different from those worn 5,300 years ago by the mummified man discovered in a glacier in the Austrian Alps.

…Technology is at its best when it is invisible. I am convinced that technology is of greatest benefit when it displaces the deleterious, unnatural, alienating, and, most of all, inherently fragile preceding technology.

Recall my walk to the restaurant wearing shoes not too dissimilar to those worn by the ancient, preclassical person found in the Alps. The shoe industry, after spending decades “engineering” the perfect walking and running shoe, with all manner of “support” mechanisms and material for cushioning, is now selling us shoes that replicate being barefoot — they want to be so unobtrusive that their only claimed function is to protect our feet from the elements, not to dictate how we walk as the more modernistic mission was.

Speaking of the shoe industry…

What are some good minimalist shoes?

I’ve worn Vivo Barefoots and Lems, and gotten good value, even though they are a bit on the expensive side. There are cheap hipster shoes offering zero drop, like Tom’s or Vans, but the flat bottom doesn’t conform to the foot’s natural shape, so you don’t get the full dolphin feedback Bowman is talking about.

If you are a Rich-and-Cool-Guy™, ICanChu makes a very nice looking hiking shoe (Chukka) and dress shoe (Derby).

The worst thing you can do is try to insulate your feet from any discomfort.

For the non-conformists, there’s TOD’s tan leather Moccasins, and Xero sandals. Freet are affordable, and like all barefoot shoes they offer “freedom for your feet.” Vibram’s FiveFingers and Sockwas (slogan: “Free Your Sole”) are the most odd-looking, but provide the most feedback short of going barefoot.

Vivo Barefoot makes normal looking shoes; while they’re not cheap, they will outlast most regular shoes.

If you’re on a budget, Tesla (not the car company) wins the award for the cheapest barefoot running shoe, but also check out Kigo for an affordable and stylish shoe. They sell just one shoe, making it a truly minimalist brand.

A Redditor has done a service of listing all of the lesser known companies here.

A Note on the Transition: Go Gradually, and Let the Ground Teach You to Walk and Run Properly

These principles illustrate how minimalist shoes prevent injuries from developing and promote better walking form over time. However, The New York Times highlighted some credible studies back in 2011 suggesting that people with significant injuries, weak arches, or poor walking form might make their injuries worse by switching over whole hog. These studies usually look at people who did not transition gradually. Giving up the cushion means less protection as your foot muscles and ankle joints are gaining strength, but if you don’t have injuries in the first place, then the protection will only be more likely to lead to injuries over time.

As soon as you start wearing a minimalist shoe, you will notice a natural tendency to switch from a heel- to a toe-strike or midfoot strike. But you still have to be mindful and consider your form. Barefoot running, for example, is optimized at a cadence of around three beats per second — that’s one-two-three, one-two-three, one-two-three (incidentally, 180 beats per minute is also the cadence of the song “Life is a Highway” by Tom Cochrane).

At this speed, your legs will automatically function more like springs or pistons that you “charge up” by leaning forward slightly, pulling one knee upwards, as if you are falling, and then accelerating the knee down. You will gradually build up more of a spring in your step as your achilles tendon becomes more elastic.

I don’t really know of any technique for barefoot walking other than to stand up straight, relax, and pay attention to the signals your feet are giving you. You will naturally land a little bit gentler on your heel, and you will feel your toes as they make contact with the ground with each stride. If it really hurts, you should probably consult someone who knows more about foot mechanics than I do, but be warned that podiatrists are not entirely reliable on this question. They have a vested interest in the narrative that we need special products and medical procedures to fix what’s not always broken.

This piece was originally posted at A Natural Method. Subscribe for advice on surviving the late anthropocene.

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