Absent any social obligations, fashion expectations, or store regulations regarding the necessity of footwear, would you choose to go barefoot as often as possible?
I think you would. Most people, when they get home after work, or vacation in a tropical locale, kick their shoes off. It's a momentary whim satisfied, but you could never, ever, for example, go to a job interview in bare feet. It just isn't done, right?
But doesn't the existence of that instinct toward kicking your shoes off, that inclination toward freeing your feet, make you wonder why? Instincts, after all, are there for a reason. If you dig deep enough and go back far enough, any particular instinct conferred some survival benefit to the organism with the instinct. Now, some instincts are obsolete, or even detrimental, in the modern world -- like tribalism, which served a distinct purpose for hunter-gatherers but only sows discord, hate, and fear today. But others still make sense: an infant's propensity toward putting things in its mouth (introduces novel bacteria to their budding immune systems); a teen's, ahem, primal urges when it comes to sex (allows the propagation of the species, with some caveats, of course!); and our love of sunny days (sun exposure provides vitamin D, an essential micronutrient for health). I'd argue that our love of being barefoot is a similarly beneficial instinct.
If you look at the structure of the foot itself, it's a remarkably complex piece of machinery, with more than 26 bones, 33 joints, and over a hundred tendons, ligaments, and muscles. It's also one of our oldest bodily features, having been essentially unchanged since our graduation into full-on bipedalism at least four million years ago. Bipedalism was a really big deal for our early human ancestors. Walking upright freed our hands for tool making and usage, it gave us greater visibility across the Saharan grasslands for spotting prey and predators, and it reduced the amount of skin directly exposed to the sun when it was at its harshest and brightest. It allowed us to travel great distances more efficiently than quadrupeds. And it was all done without expensive Nikes. Anthropologists place the earliest footwear at about 40,000 years ago, probably a protective measure to guard against snow and ice. So, for the vast bulk of our evolutionary history, the human foot was designed to handle the rigors of walking and running in its completely natural, bare state.
We've still got those same feet, but we don't use them anymore. Instead, we cover them up. We wear shoes that alter the structure and function of our feet, and that weaken the myriad tendons, muscles, and ligaments through disuse. We strap on rubber soles that sever our proprioceptive connection with the ground and restrict our nervous system's ability to subconsciously respond to changing environments and protect us from tripping or turning an ankle.
An early 20th century orthopedist named Philip Hoffman had a similar idea. His mostly ignored 1905 study, titled "Conclusions Drawn From a Comparative Study of the Feet of Barefooted and Shoe-Wearing People," (gotta love the blunt frankness of early research) did exactly what the title states. He looked at the feet of people who spent their lives barefooted, of people who started out barefoot and then "graduated" to shoes, and of people who grew up in shoe-wearing cultures. The results were clear: lifelong bare footers displayed wider feet with wider toe beds and fewer foot dysfunctions, while shoe-wearers displayed narrower feet, narrower toe beds, and many more foot dysfunctions. And the shoes acted quickly, too; individuals who had spent most of their lives barefoot experienced significant, rapid alteration of the foot structure after a few weeks of wearing shoes. In the end, Hoffman concluded that of the "one hundred and eighty-six pairs of primitive feet examined, [he] did not find a single foot associated with the symptoms of weakness so common in adult shoe-wearing feet, which are weakened by the restraint the shoe exerts over function." Take a look at the linked PDF, because the pictures are startling.
This is not an appeal to the naturalistic fallacy. This is simply stating a fact: the human foot was designed by millions of years of natural selection to work in its unaltered state. Putting on thick, restrictive shoes with prominent heels and lots of padding puts us at a greater risk of lower body injuries, both chronic and acute. It allows the muscles in our feet to atrophy from disuse. And once that primary link between our bodies and the ground is compromised, the rest follows: ankle pain, knee pain, hip pain, back pain.
So, what can you do if you've been wearing shoes your entire life, or if you're already suffering from foot, leg, or knee pain? Throw in the towel and pony up the money for orthotics? No way! Need arch support? Use your built-in arch support! Just as dealing with the ramifications of tribalism, by ignoring the problem, only exacerbates the situation, sticking your feet in a desensitizing, immobilizing cast made of rubber and leather in order to reduce lower body pain avoids the root cause of the problem and focuses on the immediate symptoms.
Go barefoot as often as possible. It's as simple as that.
Ditch the shoes when and where it's acceptable: at home, on walks around the block, at the park. Working in the office? Go in socks and leave the shoes under the desk. Go to the beach and take a long walk. Grasp the sand with them and flex your foot muscles.
As with any muscle you haven't been using for an extended period of time, your feet are probably weak, and rushing into mile runs or two hours hikes in unprepared bare feet will be painful and potentially dangerous. Ease your way into it, especially if you're habitually shod.
Free your feet, pay attention to the sensations, and walk the way your genes intended.
Mark Sisson is a former elite marathoner and triathlete. He is the author of the best-selling health and fitness book, "The Primal Blueprint", and publisher of the health blog, MarksDailyApple.com. Become a fan on Facebook and visit Mark's blog for daily health tips.