How We Move [Part 2 in The Case for Minimalist Footwear]

This article was originally published on May 15, 2009 at ADVENTUREinPROGRESS. It has been moved to this site so that all of my minimalist footwear articles exist in one place.

When I first started to investigate the possible options for my foot, knee, and back problems I approached it from the standpoint that my body was flawed and I needed a solution to compensate. I looked at shoes, orthotics, knee wraps, and anything else that I could find. As I began to familiarize myself with products, something struck me about how many of them were marketed: they were being billed as natural, ergonomic, and bio-mechanical technologies to support and strengthen the feet and legs as if one were barefoot. Some examples of the products I found were MBT (Masai Barefoot Technology) shoes, Nike Free shoes, Birkenstock shoes, and Barefoot Science insoles. After thinking about it for some time, I asked myself the questions:

If barefoot and natural foot function are so important, why do I need special products to achieve that?"

What would happen if I just go barefoot?

In order to answer those questions, I decided that a good place to start would be to learn about how the feet were designed to work.

Our bodies are designed with an amazing shock absorption system. It is capable of handling everything from the mild impact caused by walking, all the way up to the large impact experienced when jumping over or off of an obstacle. Our body behaves like a spring, bending at the joints and using the tension of the muscles to absorb impact. The nerves of the feet are used to sense the impact and provide real-time feedback to the rest of body to minimize the shock.

When walking on uneven terrain (you can try this yourself by walking barefoot on a rough surface), the forefoot - the pad on the bottom of the foot which sits back from the toes - is the first part of the body to touch the ground. This can be observed in the the following photos I took of my daughter on a treadmill:

Walking - Note that the forefoot is the first point of contact when taking a step

Running - As with walking, the forefoot again is the first point of contact

As our foot comes down to make contact with ground, several observations can be made. First, all of the major joints in the foot and leg are bent. The bent joints provide the flexibility (vertical travel) required to dissipate the shock. A second observation is that the the muscles in the feet and legs are flexed and ready. The muscles are prepared to provide the stability for the joints and resistance to the load. A third observation (not seen in the photos) is that there is a heightened sensitivity in the feet. The nerves of the feet are like pressure sensors, ready to provide feedback regarding the severity of the shock.

As the body transfers weight to the forefoot, the toes spread and mold to the terrain, providing a stable platform on which to land. The muscles of the foot engage the arch, the heel begins to drop down towards the ground, and the load starts moving to the calves. The joints in the feet, ankles, knees, and hips bend while the muscles flex and absorb the the shock as can be seen in the following photos:

Walking - Because walking is lower impact, the knee is bent only slightly

Running - Because running is higher impact, the knee is bent more to absorb the shock

The same nerves, joints, and muscles that provide shock absorption also provide stability. The human foot has thousands of nerve endings. When we walk, the primary feedback our bodies get regarding the terrain on which we are walking is through touch. Through touch, our body is able to determine whether the surface is hard, soft, textured, slippery, uneven, or unstable. Based on this information the body is able to make adjustments to compensate as appropriate. It may do this any number of ways:

• by molding the foot to the shape of the terrain
• by engaging muscles in different parts of the foot or leg for stability
• by shifting weight to different parts of the foot
• by re-distributing weight to the other foot
• by bailing-out if the situation is deemed precarious

Of prime importance to stability is having joints that are free to move through their full range of motion, and muscles that are developed to support them. When the joints are bent, the muscles are engaged and able to do their job of stabilizing he body. The joints of the feet, especially the toes, must be able to bend and spread in order to follow the contours of the ground providing a stable platform on which to step. If the joints are restricted, straight, or locked, the muscles dis-engage and the body becomes more rigid and less stable.

The following photos illustrate how the flexibility of the foot is used to mold to uneven terrain:

Putting it all together... the nerves, bones, joints and muscles and how they work in concert to provide locomotion, shock absorption, and stability is nothing short of amazing. In fact, all the subtleties that make the system work so well cannot be fully appreciated until you do something to hinder it: put on footwear. For most of us, however, it is the exact opposite. We are so accustomed to being hobbled by shoes that we don't know what it is like to move naturally.

Enough theory, back to my story. After researching and discovering that there might be some benefit to going barefoot, I decided I may as well give it a try. I was willing to do anything at this point, I had nothing to lose: my feet were in pain, my knee hurt, my back hurt, and going barefoot was free. It was kind of like hitting rock-bottom, there was nowhere to go but up. Want to know how it felt? Let's just say at first, not so great. But you'll have to come back next time to find out more.

Other Articles in the Series

• Part 1 - My Journey to Discovery
• Part 3 - How Footwear Affects the Way We Move
• Part 4 - What Does the Research Show
• Part 5 - Selecting Minimalist Footwear
• Part 6 - Making the Transition