Rabu, 05 Maret 2008

Running shoes continued

Running shoes and injuries: Debate continued

Yesterday, we did a short post looking at the debate around running shoes, and whether the shoes which claim to reduce injury risk are in fact part of the problem! Thanks to everyone for the spirited input on the debate - it's been lively and interesting so far. I thought it better to respond in a new post and perhaps lead the discussion based on those comments than bury my response in the Comments section to that post.

Another study on expensive shoes - money doesn't buy you comfort

First, thanks to Clyde for providing the link to the article from BJSM. You can find the article abstract here if you would like to read it. I have a copy of the article as well, and it makes for some interesting reading.

Basically, the researchers set out to evaluate three differently priced running shoes:
  • Expensive - priced over 70 Pounds (around $140 or R1100)
  • Medium price - around 60 Pounds ($120 or R900)
  • Low cost - 40 Pounds ($80 or R600)
The shoes were evaluated primarily on the basis of pressure under the foot and comfort, which is a subjective rating. So they didn't really tackle the issue of motion-control/anti-pronation devices, which is a pity (but more on that later).

Their findings? As you probably might have guessed based on Clyde's comments and the general trend, there were no differences between the shoes for either of these two factors - the cheap shoes produce the same pressure (cushioning), and the same perception of comfort as the expensive shoes. The difference in price of R500, then, results in little difference in terms of cushioning or comfort or pressure distribution.

In a follow up letter to this article, the reasons for this were pointed out - it's simply not feasible to change pressure by shoe-design, because the result would be a dramatic change in biomechanics - the analogy would be to switch from running on tarmac to running on soft, spongy sand. So in effect, the above-mentioned study was "doomed" to find no difference anyway. And of course, this might be true, but then it introduces the obvious question - if shoes can't change the pressure/cushioning, why the enormous price difference? And that's where the debate leads next...

What is missing - research on the 'gadgets'

This study is interesting in that it evaluates one aspect of running shoe design - pressure or cushioning. However, it fails to tackle what I believe is the bigger source of "controversy" around the shoe industry - all the gadgets and gimmicks that are inserted to provide MUCH NEEDED support to runners who over-pronate.

And a good many of the comments to our previous article are from runners who do pronate and have had experience in these shoes. Basically, the premise for these shoes is that upon landing, excessive pronation, which refers to the rolling in motion of the ankle (called eversion of the foot), is responsible for injury, since the pressures and loads placed on the shins and knees is excessively high. Therefore, control the pronation and you control the injury risk...

So shoe companies have all developed their own unique devices to do this. Apart from the devices that are proposed to aid with cushioning (Nike Air, Asics Gel, Adidas Adiprene, and so on), I would dare say that most of the product (and price) differentiation takes place with regards to these motion-control devices. Yet so little research has been done on them. Well, let me qualify that - there is "overwhelming evidence" on all of them, but they're done exclusively by the shoe companies and never published! The funny thing is, I can almost guarantee that one company will have research that proves their device superior, while another, having done almost identical research, will conclude that theirs is the best available!

So it's hardly surprising that Dr Richards and most of you writing into this post are suggesting that anti-pronation shoes are being over-emphasized, and that a well-cushioned shoe is the way to go.

My personal take on the issue - it's the training, not shoes

So let me take that one step further and actually put my head on the block on this one. I fully agree with that assessment - I don't believe that huge, heavy anti-pronation shoes are the solution for running injuries. I stated yesterday that if I were advising an athlete with injury problems, I'd look first, second, and third at their training, and then start to consider their footwear! The point is, training errors are responsible for injury, the rest is detail!

Of course, factors like biomechanics, muscle strength or flexibility imbalances are contributing factors, and so if a runner is "biomechanically correct" (incidentally, that term is thrown around with freedom but without a clear definition of what it actually means! But that's another issue!), they will get away with training that would cause injury to someone who is not so fortunate. Body size and weight are key factors, and then of course, you get leg length discrepancies that throw off alignment, making some people far more susceptible to injury - the result is that one person's ideal programme is another's "boot camp", guaranteed to break them down in a few weeks!

However, I don't believe that simply changing the shoe is the solution - changing the training, and gradually increasing the load is far more likely to resolve the injury.

At the two extremes (high arches or very flat feet), I believe that orthotics may be helpful. I myself have very flat feet (I could probably walk on water if I tried, and certainly on snow!) and I've been in orthotics before. However, I found they caused more problems than they resolved - super rigid, stiff and heavy. So I eventually ditched them, went back to the drawing board as far as training goes (did I mention that I believe training is the key to injury?), and basically started running as a beginner again - I spent a month doing a walk-run programme, consisting of 5 minutes jogging, 2 minutes walking, and eventually managed to phase out the walking part, and the problems are a thing of the past. And all in a pair of very well cushioned, neutral shoes. I certainly lie on the far end of the pronation continuum, but I really am convinced that given the right training, anyone can wear neutral shoes. I don't believe that buying a super-expensive motion control shoe will improve your chances, rather look at orthotics if you feel you have to obtain some support.

To sum up - when you buy your shoes, try them on for comfort and cushioning and fit, and once you find what works, then stick with it. But don't commit to the 'gadgets', well cushioned is sufficient.

The future of the shoe industry

Finally, if I may put on my marketing hat for a moment, I would predict that the heavy motion-control shoe will one day become an extinct species - it may already be on the endangered list! It's difficult to know what stimulated the massive growth in the area, but I suspect what happened was that in the 1970's, when the running "boom" hit, a good many people with "less than perfect" biomechanics took up running. And of course, marketing is all about meeting people's NEEDS. And when the NEED doesn't exist, then you simply create it - "science" is often a big help in this regard!

So the companies recognized that perhaps a million people who never ran before were now running and this represented a huge market to be tapped into. But they needed a selling point, and Point of Differentiation, and the "combat overpronation" campaign was just the ticket!

Now, in 2008, I feel the opposite is happening. More and more people are talking about barefoot running, which is probably a little too extreme, a case of over-compensation, perhaps. But the point is, there is a shift in the market, and I'm sure the companies will respond and try to create a new need - I suppose they already have, with the barefoot shoe concept. But all this adds up to the beginning of the end for the heavy, anti-pronation shoe, which will probably become a relic in the next 20 years. But then again, those may be famous last words!

Thanks again for the debate, keep it coming!

Ross

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