I got am email asking me what I thought of the recent study in the Physician and Sports Medicine about those with plantar fasciitis improving more in barefoot or minimalist shoes (Nike Free) compared to conventional shoes. Here is the abstract:

Plantar fasciitis is a common injury to the plantar aponeurosis, manifesting as pain surrounding its proximal insertion at the medial calcaneal tubercle. Pain is typically worse in the morning when getting out of bed, and may subside after the tissue is sufficiently warmed up. For running-based athletes and individuals who spend prolonged periods of time on their feet at work, plantar fasciitis may become recalcitrant to conservative treatments such as ice, rest, and anti-inflammatory medication. Exercise-based therapies have received only limited attention in the literature for this common problem, yet they are becoming increasingly validated for pain relief and positive tissue remodeling at other sites of similar soft-tissue overuse injury. This study reports on pain outcomes in individuals experiencing chronic plantar fasciitis while wearing a shoe with an ultraflexible midsole (Nike Free 5.0) (FREE) versus a conventional training (CON) shoe in a 12-week multielement exercise regimen, and after a 6-month follow-up. Adults with >or= 6-month history of painful heel pain were recruited and randomly assigned to wear 1 of the 2 shoes. All subjects completed the same exercise protocol. A visual analogue scale item tracked peak pain in the preceding 24 hours taken at baseline, 6- and 12-week points, and at the 6-month follow-up. Twenty-one subjects completed the program (9 FREE; 12 CON). Both groups reported significant improvements in pain by the 6-month follow-up, and the FREE group reported an overall reduced level of pain throughout the study as a result of lower mean pain scores at the midpoint and post-test compared with the CON group. The exercise regimen employed in this study appears to reduce pain associated with chronic plantar fasciitis, and in doing so, the Nike 5.0 shoe may result in reductions in pain earlier than conventional running shoes.

The data presented in the study did not support the conclusion made by the authors and this shows how easy it is to jump to conclusions based on just reading the abstract. The data may have actually shown the opposite to the authors conclusion!

When researchers publish their research, they like to publish it in what are called high impact journals. This is a complicated formula based on a number of factors. Due to competition only the best research theoretically makes it into the high impact journals. Because of this, poorer quality research theoretically makes it into the lower impact journals. The Physician and Sports Medicine is a lower impact journal. To publish a randomized controlled trial (like the above one) in a high impact journal, then the reporting almost always has to comply with the CONSORT standards. This is a standard method of analysing and reporting the results of randomized controlled trials agreed to by the editors of many of the high impact medical journals. This allows for a high level of transparency in analysis and reporting. Most of the low impact medical journals also adhere to this standard, but based on the above research, the Physician and Sports Medicine does not appear to.

In the above research, those with plantar fasciitis were given a standard treatment protocol with the only difference being one group kept their conventional running shoes and the other group were given the Nike Free. Their analysis showed non-statistically significant greater initial improvement in the group using the Nike Free (which is problematic conclusion on its own, but I won’t go that way). What the abstract does not say (but the full publication does say) is that the symptoms of two subjects in the Nike Free got so bad that they had to withdraw from the study, so their data was not included in the final analysis. One of the key tenants in the CONSORT statement for the analysis of randomised controlled trials is what is known as ‘intention to treat’ analysis, in that the data from those who withdraw need to be included in the analysis. So the pain scores from the two subjects who got worse in the Nike Free’s who had to withdraw should have been included in the analysis. I am sure you can see if they had done that, the results from the study would have been very different. The results would have probably have been no difference between the two groups or even the Nike Free group doing worse (as two subjects got that bad they had to withdraw!).

I do not know why the Physician and Sports Medicine allowed publication of this study without the ‘intention to treat’ analysis which is the accepted ‘gold standard’. One thing I do know is that this study will find its way into the teaching resources of research methods courses as a classic on how to understand ‘intention to treat’ analysis and why it is important.

I did check around the barefoot running websites and was pleasantly surprised that they were not touting this research as being evidence for minimalist running shoes (or even barefoot running!). Good on them for that. They will certainly be making fools of themselves if they did and providing more evidence of their intellectual dishonesty.

Who can remember the media flurry and hype on barefoot running sites when Craig Richards published his systematic review last year: Is your prescription of distance running shoes evidence-based in the British Journal of Sports Medicine? Here is the abstract:

Objectives: To determine whether the current practice of prescribing distance running shoes featuring elevated cushioned heels and pronation control systems tailored to the individual’s foot type is evidence-based.
Data sources: MEDLINE (1950–May 2007), CINAHL (1982–May 2007), EMBASE (1980–May 2007), PsychInfo (1806–May 2007), Cochrane Database of Systematic Reviews (2nd Quarter 2007), Cochrane Central Register of Controlled trials (2nd Quarter 2007), SPORTSDiscus (1985–May 2007) and AMED (1985–May 2007).
Review methods: English language articles were identified via keyword and medical subject headings (MeSH) searches of the above electronic databases. With these searches and the subsequent review process, controlled trials or systematic reviews were sought in which the study population included adult recreational or competitive distance runners, the exposure was distance running, the intervention evaluated was a running shoe with an elevated cushioned heel and pronation control systems individualised to the wearer’s foot type, and the outcome measures included either running injury rates, distance running performance, osteoarthritis risk, physical activity levels, or overall health and wellbeing. The quality of these studies and their findings were then evaluated.
Results: No original research that met the study criteria was identified either directly or via the findings of the six systematic reviews identified.
Conclusion: The prescription of this shoe type to distance runners is not evidence-based.

This was greeted with headlines in the news media, on running forums and on barefoot running websites as evidence that expensive running shoes are bad (do you remember the headlines?). Can anyone actually see anywhere in this study where they actually showed that? This is just further evidence of the intellectual dishonesty of the barefoot running community that they would interpret the research that way and promote it as saying that.

All the study found was that there was no evidence to support the prescription of distance running shoes. They found no evidence because there is no evidence as no one has done any good research on it! Just because there is no evidence for it, does not mean that running shoes do not help. It does not mean that they don’t either. Why did the barefoot running community take this as evidence that running shoes are bad?

I have no problems with the study and agree with the conclusion. I do have a slight problem with the way the article was written and its tone as it was obviously written by someone with an agenda (the author is a barefoot runner and has a financial interest in a barefoot running product). However, I will not dismiss the study because of that. The barefoot runners with their blinkers on will love the biased tone that the article was written with!

If a study did come out and did show that running shoes helped and was funded by the running shoe industry, how would the barefoot running community react to that? Would they dismiss it because the running shoe industry funded it? Are they prepared to dismiss the study above because it was done by a barefoot runner? Are they prepared to dismiss the Liebermann et al research because it was done by a barefoot runner and funded by a barefoot running company? It will be interesting to see how the barefoot running community react, as that research is coming.

Despite claims to the contrary by the barefoot community, there is NO evidence that barefoot running is better than running in running shoes. How should we interpet that lack of evidence? Should we do what the barefoot running community did and conclude that barefoot running is bad as there is no evidence to show that its good? Can you see the absurdity of that conclusion? Well, that is exactly what the barefoot running community did in the way they interpreted the Richards review above!

The key point is, you can’t have it both ways.

That is what the barefoot running community and the anti-running shoe community would have you believe.  You see this claim being made all the time on barefoot running websites, books and on running forums. We know that the barefoot running community are really good at all sorts of intellectual dishonesty, should we believe them on this one as well?

Given the strength of the claims being made, you would expect there would be at least some evidence to back it up wouldn’t you?, but there is none! They only want to believe it to be the case as it helps their agenda. Certainly many individuals who start barefoot running claim that their foot and leg muscles are stronger – but are they really stronger? Or do they just feel different as the barefoot running gait is different? Or do they deceptively feel stronger because they want them to feel stronger? (see this post on why individual experiences are flawed).

In the context of the lack of evidence either way as to if running shoes weaken muscles or not, what other information do we have that could guide us to some sort of rational conclusion rather than some uniformed nonsense due to the wearing of blinkers. What about foot orthotics? Do they weaken the foot? You certainly see it claimed a lot by those who have not read the evidence. Two studies have looked at muscle strength and the use of foot orthotics. One by Mayer et al actually showed the opposite and foot orthotics increased muscle strength! The other study that looked at this showed after 4 weeks of orthotic use that there was a non-statistically significant increase in strength, so certainly no signs of a decrease in muscle strength which I would have thought would start to show by 4 weeks if it was going to happen. Now, obviously foot orthotics are not running shoes, but despite widespread claims that foot orthotics decrease muscle strength, all the research evidence is that either they do not or they increase strength!. Can this be extrapolated to running shoes? Maybe? Maybe not? What this research does do is calls into question the unsupported claims that running shoes do weaken the muscles.

Then there is the one EMG (electromyography) study that compared running shoes to barefoot. They found no systematic differences between barefoot or running shoes. Some muscles activated earlier in barefoot and some activated earlier in the running shoe. If the running shoes were weakening muscles, then why are the EMG studies NOT showing a systematic decreases in timing and amplitude of muscle activation? Certainly no sign of any muscle weakening here!

What about the Bruggeman et al study that looked at muscle strength after runners were randomised to their conventional shoe vs the Nike Free (which is not really barefoot, but is a minimalist shoe). They showed what appeared to be an increase in muscle strength in the Nike Free group. I have no problems with the study (except a few minor issues and it was funded by Nike). But consider these two points:

1. The study was NOTHING to do with conventional running shoes weakening foot and leg muscles (which strangely has been interpreted as showing that by some!).
2. Why did the Nike Free group of runners get an increase in leg muscle strength? Was it because being close to running barefoot is a good thing? (this is the interpretation that the barefoot running community would like to put on it). But what about the opposite conclusion? Could it be that the muscles got stronger because they had to work harder in the Nike Free shoe? Increased muscle activity is a bad thing as it is a sign of an inefficient gait. If the muscles are having to work harder, then performance will be affected. Surely that is a bad thing? Strange how the barefooted community with blinkers on can draw one conclusion when there are other possible conclusions that can be drawn.

Conclusion: We actually have no idea if running shoes lead to weaker muscles or not. However, if we want to extrapolate the orthotics and the EMG evidence, then it could certainly be suggested that they do not. There is certainly more information pointing to running shoes not weakening muscles than the nonsenscial and unsupported claims by the barefoot running community.

You can often read comments or statements to the effect that running shoe technology has allegedly improved massively over the last 20-30-40 years, yet when you look at the epidemiological studies of running overuse injuries, there has been no change. The barefoot running community tend to use such statements as evidence that running shoes are bad. You also see many claims in barefoot running books and websites, that the injury rate is actually going up. But like other bits of intellectual dishonesty, they just do not seem to get it and repeatedly twist things to suit their agenda.

Yes, if you look at the marketing of running shoes and the technological development of running shoes, there is an apparent improvement in the features that are claimed to help reduce running injuries.

Yes, if you look at the old and more recent prevalence and incidence of running overuse injury studies, the rates of injury are pretty similar (as an aside, most comments I have seen in running barefoot books, on running forums and barefoot running websites on this, show that they do not even know the difference between the words ‘incidence’ and ‘prevalence’, so how can you trust any interpretation they make of the research of they can’t get the basics right?).

But, if you dig a little deeper, the comparisons between then and now do not stack up to scrutiny. You will not be able to find a single epidemiologist (the specialists who do these sorts of studies for a living) who would agree that the comparisons between the older studies and the newer studies are valid. If they are adamant you can’t do this, then why do the anti-running shoe community think they can do it?

Why can’t you compare them? Because:

• The populations used are different in different studies
• The selection of the populations are different in different studies
• The definition of an injury was different in different studies
• The collection of the data was different in different studies
• Running has changed over time (I came across a comment recently that the average marathon time in the 80’s was 3hr 8min and these days its around 4hr 20mins – how can you compare these two different populations?)

On the surface, it does appear the injury rate across studies over time has not changed, but dig below the surface and you cannot make that comparison. It’s simply not valid. If you want to beat up on running shoes, you are going to have to find something else rather than dig a bigger hole for yourself using this data.

When you look at many of the websites and blogs that promote barefoot running you cannot help but be left with the impression that running shoes are close to being the source of all evil on this planet. “Global warming can be reversed and world peace achieved if we just stop wearing those damn running shoes“.

Seriously, folks, do you honestly believe that the running shoe industry would deliberately make and sell running shoes that they know will actually cause harm (let alone global warming and wars). That is what many barefoot running commentators would want to have you believe.

Yet, I can find no evidence of running shoes doing any harm. I do see many comments on barefoot running websites, but like a lot on these sites, it not backed up with any evidence. The evidence that they help is also lacking, but the lack of that evidence does not mean that they don’t. However, the illogical rationale of some barefoot runners is that they do cause injury because there is no evidence that they help – I assume you can see the illogical argument they put forward.

If you check out some of the characteristics of what constitutes a conspiracy theory, then the barefoot running community (in general) meet all or almost all of the criteria in their belief of a big conspiracy by the running shoe companies. Seriously, folks, do you honestly believe that the running shoe industry would deliberately make and sell running shoes that they know will actually cause injury.

If you believe that, then I think it’s time you took off your tin foil hat*.

* If you do not know what this means, then check the Wikipedia entry.

A number of studies have compared the prevalence of foot problems in shoe wearing and non-shoe wearing populations. They quite clearly showed that there are more foot problems in the shoe wearing population. Why is it that the barefoot running community promote these types of study as supporting barefoot running? I just do not understand what they have to do with barefoot running.

But, is this another case of intellectual dishonesty by the barefoot running nutters? How do you actually know that the footwear was the cause of the higher number of foot problems? In many of the studies that have reported on this, there were ethnic, genetic and age differences between the two populations. How do you know that this was not the reason for the difference in the prevalence of foot problems and nothing to do with the shoes? How do you know that the shoe wearing populations did not spend more time on their feet and this was the reason for the increased prevalence and nothing to do with the shoes? How do you know that the shoe wearing population did not spend more of their time on hard surfaces than the non-shoe wearing population and the hard surface is the reason for the increased prevalence of the foot problems?

Why is it that when the barefoot runners tout these studies as supporting barefoot running and they do not acknowledge these possible shortcomings in the research? Why do they not acknowledge the other possible explanations? Is it because they are so blind in their faith, that they just want to believe?

I am not for one minute saying that the shoes are not to blame (they probably are), I am just pointing out that this sort of conclusion cannot be drawn from these sorts of studies and that the barefoot runners are distorting the results to suit their cause. Why do they continually to that for?

I still do not understand what this has to do with barefoot running.