Over the summer we had several people who emailed us about a problem they were having with their sandals. The sandals were drifting slightly to the outside of the foot and in the case of the Pah Tempe models, the foot was coming off the front. One case was especially bad. Since I founded Unshoes over 5 years ago I had only seen this problem a few times. It seemed more prevalent this year so I began to worry that maybe it was a design flaw. While we have changed some small design elements, the basic design of the sandals is the same and has remained unchanged. We got some of the sandals returned so we tested them on other people. The problem didn’t repeat so I could only assume that it was being caused by individual gait patterns. I took my sandals and walked around trying different things until I could (more or less) replicate the problem. To me it felt like a very strange way of walking but in my experience and after reading this book, by Biomechanist Katy Bowman, I know that the mechanical environment that we spend most of our time in will shape and mold your gait and movement patterns. It might feel weird to me but for others it might feel completely normal.
Later that day I was at the grocery store and because I’m the weirdo that’s always looking at people’s feet, shoe choices, and gait patterns, I happened to see someone walking just the same way that I had earlier to replicated! I watched the person for a moment as he walked with feet drastically turned out clapping his forefoot down in a scuffing motion. I did notice that he was wearing a pair of cheapo flip flops. The very next day I was at the thrift shop when I saw someone else walking the same way. Immediately, I noticed what they were wearing. You guessed it, flip flops! I was intrigued so I started actively looking at gait patterns everywhere I went (In case you’re getting embarrassed imagining me staring rudely at everyone’s feet, rest assured that I’ve developed a talent for discreet foot staring methods, or DFSM). Of course each individual had a slight variation, all of the people I observed shuffling along like that were wearing flip flops. Most of them were the really cheap, or ill fitting flip flops. I started calling it the flip-flop-clop.
After observing this gait all summer I came up with my very unofficial and unscientific hypothesis. In a more natural walking gait pattern you shift the weight of the body from the back of the foot to the front of the foot while using leg (glute) muscles and pushing off with the toes to propel your body forward. Now imagine wearing flip flops. They are not secured to your foot so after the forward propelling motion of walking and pushing off the ground with the toes, your foot is left for an instant with your toes pointing downward which means that the sandals fall off slightly. To keep the sandals on, the wearer must “clench” their toes. You can read Katy’s blog for more information on the consequences of excessive toe clenching. Now suppose that you don’t want to clench your toes but you still want your flip flops to stay on. What do you do? First of all, after the toe push off, you don’t let your toes straighten as you lift your foot. This works but the sandals still slide off a bit. To get them back on securely, you come down on your foot with a scuffing/breaking motion so the sandal stops when it makes contact with the ground but your foot keeps going forward just a bit. This forces the thong part of the sandal back between the toes. Of course people are not really thinking this motion through. Their bodies are just adapting to their environment and most of it happens subconsciously. The smooth and efficient forward propelling motion of walking becomes a jerky, inefficient, falling forward motion that some people call walking (but is really more like controlled falling).
Next time you enjoy the effortless ability to slip your feet into your favorite pair of flips, just keep in mind that your body is constantly trying to adapt to its environment. Pay a little bit more attention to how you walk in them. Even Unshoes, as much as we want them to be natural, have an effect on the way you walk. All shoes change the natural gait pattern of the body but some are more intrusive and can come with unexpected or undesired consequences.