Much Ado About Shoes
I hadn’t planned on writing a column on running shoes, even though the topic is among the most frequent questions asked of me (“which shoes should I buy”), for the simple reason that I don’t feel I’m any kind of expert in this area. Moreover, whatever I do know about shoes seems to become obsolete almost instantaneously as manufacturers discontinue one model in favor of a “new and improved” one. The technology seems to change so rapidly that it’s impossible to stay current and know what’s good and what’s bad. So when a runner asks the question, I usually give a very vague, non-committal answer.
Recently, however, a colleague passed along an article which appeared in the journal “Medicine and Science in Sports and Exercise” which I found to be quite thought-provoking. The authors’ basic contention is that not only despite, but actually because of, shoe manufacturers attempts over the past 15 years to improve the protective qualities of footwear, the incidence of running injuries has in fact increased! In other words, the very thing that is supposed to be helping us — more cushioning, greater stability — is actually resulting in greater susceptibility to injury. How can this be?
Well, the assumption the authors make in formulating this hypothesis is as follows: nerves in the plantar surface (sole) of the foot transmit information to the brain pertaining to impact forces, uneven surfaces, etc. This information is processed and then sent back down to moderate the gait pattern so as to avoid unpleasant sensations (pain) in the foot. This may involve greater knee flexion or foot pronation, for example, to decrease the shock to the sole of the foot. Modern footwear, with it’s high-tech cushioning, disrupts or even eliminates this “feedback,” thus altering our gait pattern to one in which impact forces are transmitted to a greater degree to the knee, hip, back, etc., resulting in overload injuries. The authors cite previous studies to support their argument which show a greater incidence of injury in shod vs. barefoot runners. They also perform their own experiment to show that humans will in fact tolerate far greater impact forces with shoes on (820% of body weight) than barefoot (190% of body weight).
Now, I’m not trying to make an argument here for throwing away our Reebok/Nike/Brooks and make like Zola Budd. To be honest, I’m more than a little skeptical about this article’s assumptions, use of statistics from previous studies and the experiment’s design. I think the authors make some pretty big “leaps of faith” in drawing some of their conclusions so I can’t really endorse their ideas entirely. But I do think they raise some interesting points which should make us pull back a little and consider whether we should be spending $100+ for running shoes to get that extra cushioning. Should we blindly follow the crowd to the store for the latest “energy-return/torsion bar/carbon cantilever system” technology without really knowing if it’s not only effective or helpful, but more importantly, safe?
My answer now to that familiar question? Save your money, stick with a simple, mid-price ($40-70) shoe that feels “good,” and take those shoe ad claims with a grain of salt. But do replace worn shoes promptly.
I hope this has been helpful. At the very least, it’s an article you’ll never see in Runner’s World!