Toe-ing the line: What I think about this whole shoe thing

Oldest discovered leather shoe: 5500 years old

I’ve had a few emails asking me to review some of the literature on the new shoe trend. Every company is jumping on the bandwagon to create their version of the Vibram five TOE shoes (sorry, I’m going to be a hand and wrist sub-specialist. Toes are NOT fingers). It’s a little reminiscent of the “body-toning” shoe thing, without all of the wildly outrageous claims, and a trend that I think will live long enough to warrant weighing in on. Most studies to date have really focused on how the shoes alter foot and gait biomechanics. I would argue that most of the claims on the Vibram website are still largely unsubstantiated or just what I call “motherhood statements”, like: “Eating your greens is good for you,” and “Puting on your jacket when it’s cold outside is good for you.” (basically, statements that don’t really have any clout one way or another, but just make you feel better.)

The claims (according to their website) are that they:

1) Strengthen your foot and lower leg muscles
2) Improve range of motion in your ankles, feet and toes
3) Stimulate neural function for improved balance and agility
4) Improve posture by removing heel lift, which aligns the spine
5) Allow the foot and body to move naturally

Oddly, the Vibram website also recommends that you consult your physician or a medical professional to see if natural running in their shoes is right for you. I’m pretty sure most physicians have about as much knowledge on running and gait biomechanics as I know about dark matter (that is, to say, I’m sure someone knows a lot about it, but I don’t know who and I sure as hell wouldn’t know if I saw it.)

In terms of possible running benefits, we know that barefoot running does tend to produce a gait that strikes more in the mid foot than the heel. Interestingly, this is the same gait change that Masai Barefoot Technology shoes (which then evolved into the rocker toning shoes) sought to achieve with a distinctly different approach to shoe design.

In a culture of increasing complexity and options in almost all dimensions of life, there is a counter-culture of minimalism, and also “naturalism” that has also sprung up. The Paleo diet is an excellent example of going back to “evolutionary roots”, and using retrospective vision to justify evolutionary arguments.

There are two main points I want to make about the new shoe issue:

1) “Everything works. Nothing works forever.”

I don’t know if Alwyn Cosgrove came up with this on his own, but he’s the one I remember saying it, so I’m going to credit him for it. It is only in the past year that the five-toed barefoot shoe trend has really caught on. Epidemiologically speaking, we’re going to experience “lag-time bias” when it comes to evaluating the effectiveness and “safety” of these shoes. The number of early adopters was small compared to the number of projected users to come before the trend hits a peak. Therefore, the number of injured individuals is going to be tiny until the denominator hits a critical mass for a pattern of injury to become apparent. It’s also going to take time for the “barefoot injury” to appear since it’s going to emerge only after prolonged chronic use. “Nintendo thumb” didn’t become apparent until well after the first generation Nintendo console had been produced. It took millions of kids hundreds of hours to develop a cohort big enough for medical professionals to make the association, and then the _causal_ association.

Barefoot shoes change your gait. There’s no dispute on that. If you have a chronic injury that is somehow linked to your gait or your posture in your non-barefoot shoes, then changing your gait or posture is going to make your injury feel different. It’s great that the general trend is that these chronic issues tend to feel better in barefoot shoes, but I like to think of it as being similar to putting a knee in a brace. Sure, your knee feels better in the brace, but that doesn’t mean your knee is any better off for it.

Do I think barefoot five-toed shoes are harmful? Not in the immediate term. Do I think that in the next few years, there will be at least a few epidemiological studies on injury patterns associated with barefoot five-toed shoes? You betcha.

2) Evolution doesn’t necessarily proceed in a beneficial direction.

One of first things a biology undergrad has to learn is to let go of the idea that evolution is always making things better. It’s easy to look backwards in time at a giraffe and say, “Well, of course the longer neck is a survival advantage because it allows giraffes to exploit a food source,” when in fact, there could have been a whole genetic start-up of longer necked pigs that never made it to the present day, or into the fossil record because there weren’t many trees in their habitat. To say that the human foot has evolved to run bare has similar pitfalls, and to state that the human foot is _meant_ to run barefoot is a La Brea tar pits full of pitfalls.

Evolving to run barefoot assumes that running provided a survival benefit; and while we all have been fed romanticized notions of hunters stalking and chasing prey and escaping vicious wild predators, I would posit that in fact, the evolutionary pressure on ancestral man was not to run, but rather to survive. Running towards or away from something is merely a single factor in successful survival. Successful _hiding_ could arguably be just as important as running; and you don’t need special shoes for that.

Lastly, there is no question that human behaviour is influenced by technology. The idea that behaving “au naturel” is the best way probably has more to do with our own romanticized ideas of battling increasing technology and further “evolution” than it does with figuring out what’s “better”. Even if feet were meant to run bare, there’s nothing that says that it’s the best way to run any more than there is anything behind the statement, “The best way to see is without glasses,” or that, “Cold weather is best experienced without clothes.”

When it comes to lifting, I think similar arguments apply, with the additional caveat that minimal-sole shoes with no toes are probably just as good. I’m not entirely convinced that the stiff sole allows for much independent toe movement, or that independent toe movement is actually that pivotal to performance or injury prevention. I’m not trying to paint all toed-shoe-users with the same brush (because some of them are my very good friends) but there’s something disconcerting about seeing a guy squat in Vibrams with 10-pound plates under his heels.

So in the end, I don’t think barefoot five-toed shoes are better than conventional shoes. I think they’re just different. If they’re a good motivational tool or a psychological support for you, then it’s probably worth your investment in them. Likewise, it’s probably not a bad thing if they’re relieving chronic symptoms–even if there’s probably a different host of aches and pains that we’re going to read about in the future. But I think their contribution to your success as an athlete, a weekend-warrior, a marathon runner, or just a joe at the gym trying to lift heavier things without getting too injured is tiny compared to the other factors that are probably in play. Wear’ em if you like, but don’t feel like you’re missing out if you’re not.

P.S. This Thursday, November 24th is Evolution Day, the anniversary of the publication of “The Origin of Species” Happy Evolution Day!