07/21/2011

For the past few years, I’ve been following the research on minimalist, or barefoot, running. My interest, and really fascination, in this research is twofold. First, I am a long time runner who used to compete in 5 and 10 kilometer races, but I also have a career in physical rehabilitation, and have worked with hundreds of runners. After seeing a myriad of running-related injuries in my patients, I began to question whether or not shoes may be contributing to these injuries. And I began to wonder if I should try going barefoot to find out.

 

vibramIn December of 2009, the American Academy of Physical Medicine and Rehabilitation published this article on the effect of running shoes on lower joint forces. The results were extremely interesting:“Increased joint torques at the hip, knee, and ankle were observed with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.”

Then Daniel Lieberman, professor of Human Evolutionary Biology at Harvard University, published this study in Nature in 2010. It was also a feature on NPR, (which really pushed me over the edge). From NPR: “Lieberman found that runners in shoes usually landed heel-first. Barefoot runners landed farther forward, either on the ball of their foot or somewhere in the middle of the foot, and then the heel came down — much less collisional force.” And I found it intriguing that when people in this study swapped shoes for barefoot running, eventually they adopted the barefoot style bio-mechanically. The reason, according to Lieberman (who runs marathons himself), is it hurts to strike heel-first without shoes (I can verify this, trust me). That is what running shoes were designed to do; lessen the impact of that strike.

In the Nature study, the discussions on impact and foot strike mirrored what had already been confirmed in the American Academy study. For rear foot strike (RFS) runners, “impact transients associated with RFS running are sudden forces with high rates and magnitudes of loading that travel rapidly up the body and thus may contribute to the high incidence of running related injuries.” So common injuries such as plantar fasciitis could be avoided if these impact forces were reduced, right? I’m beginning to believe this, but let me continue.

One of the most incredible and thought-provoking statements Lieberman makes in the Nature study is this:

“Differences between RFS and FFS running make sense from an evolutionary perspective. If endurance running was an important behaviour before the invention of modern shoes, then natural selection is expected to have operated to lower the risk of injury and discomfort when barefoot or in minimal footwear.”

And that paragraph is what made me go out and purchase a pair of Vibram FiveFingers shoes. I wanted to be the Guinea pig in my own study, and if it was all true, perhaps I could help my patients more and improve my running. The Vibram shoes are designed to fit like a glove, and mimic barefoot running, as they consist of only a thin strip of rubber as a sole. After doing careful research, I knew I’d have to prepare my feet and gradually extend my mileage over a period of time. Part of the argument of shod vs. barefoot running is that running shoes have weakened our foot musculature. So I began wearing the Vibrams all the time to help strengthen my intrinsic foot muscles, and ran the beach barefoot at least twice a week.

Now it’s not hard to FFS in these “shoes;” as Lieberman said, it’s natural because it hurts to RFS. Yet as I began to run on pavement, I found myself overcompensating the FFS. (I only discovered this after a one mile run crippled me the next day. My gastrocnemius muscles were so tender I could barely walk.) On my next run I closed my eyes as I ran (good advice from another barefoot runner) and realized what I was doing. I was trying to stay in a plantar flexed position as I ran, overcompensating the FFS. Once I let my body tell me how to run, everything changed. And I mean everything.

In the past 6 months, I’ve progressed to 6-8 miles on pavement. The best way to describe what I feel when I run now is liberated. I feel light, my stride has shortened (a natural result of the FFS), and I often want to keep running because it feels so damn good. Yet there is also a sensory element when I run now that I did not experience when I wore shoes. I feel the ground, every bump, pebble, leaf. And there is something bordering on spiritual in this kinesthetic element; running is an experience now. Physically, my body feels different, both while running and after. I don’t hurt. My neuroma and tarsal issues are gone.

While I will never wear running shoes again, the big question professionally is would I recommend patients to do the same? Yes and no. Anyone who knows me understands I loath braces, wraps and inserts. And they understand I’d rather strengthen foot arches and ankles when treating something like plantar fasciitis (instead of taping and inserts). So I do believe that strengthening the foot musculature could help a lot of people (and for most I mean walking, not running). The problem is getting there. Most people are in such poor stages of chronic inflammation and injury that you cannot expect them to start wearing minimalist shoes to walk in all the time. But I do believe if they are helped with other exercise protocols they can get there.

Should every shoe runner switch to the barefoot style? While most runners have an incredible base of running years behind them, most people do not. People that run occasionally, are overweight, and have legs as thick as linebackers, probably will have a hard time acclimating to the no-shoes style. (Although I do know a few such linebackers that are running in minimalist shoes without injury.) Body type plays a large role in foot bio-mechanics and impact forces, so not everyone should run (there is nothing wrong with walking). What remains clear to me is that everyone could- and really should try – walking in minimalist shoes, and strengthen those muscles that shoes help destroy.

At a recent Sports Medicine symposium I attended in Atlanta, barefoot running came up in a discussion lecture. The speaker was a well known orthopedic surgeon from Emory Healthcare. The question was simple: “What do you think of barefoot running?” The simple answer? “We need to do more research.” While I agree with the doctor, I’m going to slip on my Vibrams and run.