This has been a hot topic in the running, sports medicine, and, obviously, marketing for the past few years. There are two major camps in this debate. One supports modern running shoes stating that they help prevent chronic running injuries like tendonitis and stress fracture, through cushioning, supporting the arch and preventing excess motion like pronation. The other argues that humans have been running with no, or minimal, shoes for thousands of years and modern running shoes are messing with normal biomechanics that generally work just fine. I will attempt to address this issue with what information we have to date.
Running is a repetitive sport and its risk lies in the repetition of the impact forces on the body when the foot strikes the ground. This impact is absorbed by every body part from head to toe (but in reverse order). How much each body part absorbs depends somewhat on your size and running style. Nonetheless, we can divide it up into two areas: 1) muscles and tendons, 2) bones and joints. Generally, people that land towards the front of their foot put more of the stress on their muscles and tendons and people that land on the back of their foot (heel strike) put more stress on the bones and joints. Some people just naturally prefer running one way or another, but what we wear on our feet can greatly influence this.
To understand this we have to dissect the modern running shoe. Really, there are three objectives with making these shoes: 1) Cushion-mostly in the heel which makes the heel elevated above the toes. 2) Arch support. 3) Stability or Motion control-this is an attempt to prevent ankle and foot wobble, mostly pronation in the end. This is done by providing some stiffness to the area behind the toes and making the base of the shoe wider.
All of these things sound good, but some would argue that they are influencing people to heel strike and that heel strike is not natural. It may throw-off the natural gait and make you at greater risk for stress fractures. Anyone who has tried to heel strike while running barefoot has quickly found out that it doesn’t work. It just hurts after a little while. One recent study showed that running barefoot generated less ground collision forces than running in modern, cushioned running shoes. It was argued that heel striking creating increased ground collision forces. One study from the eighties showed that people wearing more expensive running shoes were two times more likely to be injured than those with cheaper shoes. If you assume that more expensive shoes in the eighties were more supportive, then this supports the barefoot camp.
Another argument against running shoes is that a taller/wider heel lengthens the lever arm of heel motion. This may actually be increasing the wobble forces that contribute to pronation. A comparison can be made to trying to walk or even run in high heels (I am not admitting to anything!). This is not an easy thing to do. Sure, it looks neat, but from behind you can really see how instability is maximized.
Enemies of the unshod would point to the anecdotal evidence that over-pronators with pain or people with plantar fasciitis feel better with arch support. And we can’t forget about the potential for cold injury and skin trauma.
Conversely, many will point to the Tarahumara people of Mexico or runners in Africa as support for people who have run incredible distances successfully for centuries with no or minimal shoes as proof that we were meant to run without the added support of modern running shoes. The only problem with this theory is that in the U.S. we have grown up wearing shoes. We were them to school, to work, and through most of the winter, and our feet become accustomed to them. If we wore sandals throughout the year it might be a different.
Herein lies much of the problem with switching to barefoot, or minimalist, running: most of our feet aren’t ready for it. If you have ever tried to do your running on the beach you have likely paid for it the next day with a lot of soreness in the muscles in your lower leg and foot. Many people jump into it too fast and get into trouble with tendonitis, strains, skin problems, and plantar fasciitis. This transition needs to be done slowly. Most of the injuries we are seeing with barefoot runners are related to switching too quickly. Walk barefoot first, then only running a mile or so barefoot initially and gradually increasing thereafter. Gradually progressing your running surface is also a good idea (grass to dirt to road). This transition can take more than a month to allow the muscles of the lower leg and foot to grow stronger and to build up the callous needed. Strengthening exercises are a good idea if you decide to make the switch. There are some people for whom barefoot running is not going to work. This is likely best addressed on a case by case basis.
In the end there is no good evidence out there that shows that modern running shoes cause injuries or barefoot running decreases injuries. Perhaps the most important question is not what you wear while you are running, but what you wear when you are not running to predict how successful you are going to be with it.
Matt Evans, MD
- Do you run barefoot?
- Minimalist shoes, are they a fad or are you a believer?
- How long did it take you to transition to running barefoot or in minimalist shoes?
- Do you think you’ll get there eventually?