Yet another study they fell for!

by admin on February 2, 2010

In the January issue of Nature is a study by David Liebermann et al (Foot strike patterns and collision forces in habitually versus shod runners). Like the recent Kerrigan study the barefoot running community have fallen for this one as well (see Hook, line and sinker to see how intellectually dishonest they were about that one). Now they done it again with this study!

Like the Kerrigan study, the Liebermann one has been widely picked up by the media and touted on the barefoot running web sites and on running forums. I doubt these people even bothered to read the research and just parroted the press release (how irresponsible is that?). It is clear that they never bothered to read the publication! They are making claims for it that the research did not show! The authors even had to take the unusal step of putting a statement on their website about how the research had been misinterpreted and misreported! (good on them for that).

Here is the study’s abstract (and NOT the overhyped press release):

Humans have engaged in endurance running for millions of years, but the modern running shoe was not invented until the 1970s. For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes. We wondered how runners coped with the impact caused by the foot colliding with the ground before the invention of the modern shoe. Here we show that habitually barefoot endurance runners often land on the fore-foot (fore-foot strike) before bringing down the heel, but they sometimes land with a flat foot (mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast, habitually shod runners mostly rear-foot strike, facilitated by the elevated and cushioned heel of the modern running shoe. Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.

The full text is available from Nature by subscription. All the study did is compare barefoot to shod running. No where did they prove that one was better than the other, yet somehow the barefoot running community have interpreted that as being the case. They have a habit of doing that!

Read the last sentence in the abstract: “and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners“. Really? Can someone point me to one piece of evidence that shows high impacts actually cause any injury? I know no one can as there are none! A high percentage of runners do NOT get impact related injuries! The barefoot running community want us to believe that impact is bad, because it supports their cause. They want to believe. But nowhere has it ever been shown that high impacts are bad and that they cause injury. In fact, the opposite has shown to be the case – we need impact for bone health and to prevent osteoporosis.

The study did not also address the higher loads that go through the forefoot and Achilles tendon in those who run with a midfoot and forefoot strike. Why is that? Why do those touting this research not mention this? They think it’s ok to mention that high impacts cause injury (when the evidence is that it does not). Is it becasue they have an agenda? (and we all know that the author of the study is a barefoot runner. Why is it that research done by drug companies on their drugs is treated with suspicion, but the barefoot running community believes that a barefoot running study done by a barefoot runner should not be scrutinised?).

Vibram Five Fingers partially funded the research. In the drug industry, drug company sponsored research is looked upon very cynically by many people. Should we also look cynically at any research on barefoot running that is funded by a barefoot running company? Personally, I have no problems with industry funded research. The problem I have is when the funding source is not declared. The source of funding was not disclosed in this publication.

Let’s take a closer look as the research:
Problem number one:
Look at the age differences in the habitually shod group and the barefoot group. They claimed in the methods to have controlled for age, but they did not. The age difference was almost double! (19.1yrs for the shod group vs 38.3 for the barefoot group). The differences in age could have accounted for the results, or at the very least skewed them.

Problem number two:
The statistical analysis is really questionable and they seem to be very deliberate in which variables they decided to analyse. Why not analyse them all and tell us the results of them all? They tried to argue that “because the preferred speed was approximately 1ms21 slower in indoor trials than in outdoor trials, we made statistical comparisons of kinematic and kinetic data only between groups 1 and 3”. This is not normally acceptable to do this.

Problem number three:
This should have been presented as a pilot study, The two groups that they actually did the statistical comparison on (groups 1 & 3) had only 8 in them (and they were the USA groups and not the groups from Kenya! – why did all the video’s and media attention focus on the Kenyan groups when they were not even included in the analysis!). How can you draw any real conclusions from such small numbers?

Problem number four:
They clearly where using some 2D analysis, yet were claiming 3D (the biomechanists will know what I mean and the problems with that).

Even the authors acknowledge that the media got it wrong. There is this on their website:

There are many discrepancies in the way the press has reported our paper “Foot strike patterns and collision forces in habitually barefoot versus shod runners” ….Please note that we present no data on how people should run, whether shoes cause some injuries, or whether barefoot running causes other kinds of injuries.

Yet again, the barefoot running community have shown their true colors in misrepresenting research and twisting the results to make statements about running shoes and barefoot running that the research did not show – let alone acknowledge the shortcomings. Why do they keep digging these holes for themselves?

If you not believe me or do not want to believe me, then critically read the research article, visit the barefoot running websites and running forums and read what they wrote about what they think this study shows … you will know exactly what I mean when you read it! Notice how they attack anyone who says anything negative about barefoot running, but never actually address the issues being raised!

{ 2 trackbacks }

What does the barefoot running community continually fall for this nonsense?
February 21, 2010 at 5:41 am
Where are all these impact injuries that runners are supposed be getting an epidemic of?
February 23, 2010 at 11:28 pm

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