Barefoot Science Foot Strengthening System

Simon:

Then why would a podiatrist want to use the medial heel skive on their patients if the evidence for the medial heel skive is "poor"? I suppose good mechanical reasoning skillls and common-sense applications of known mechanical principles to the human body are all considered to be "poor" within this glorious tower we now have standing before us, the "hierarcy of evidence", unless there is some level I or II research to confirm that Newton's Laws of Motion do actually apply to the foot also.

In other words, why would anyone be so bold to suggest that pushing harder on the medial heel with a foot orthosis would cause an increase in external subtalar joint supination moment since the evidence for this common sense mechanical prinicple is "poor" within this "hierarchy of evidence" that you are suggesting that we must all strive toward.

 

Like you said, Simon, playing Devil's advocate.....

 

I wasn't aware of the study you attached until now. So now we have a study which elevates the evidence base for the use of the medial heel skive within the hierarchy. Haven't read the study yet but I assume it is some form of observational study so we may be up to the "good" level within the hierarchy. But does it measure clinical outcomes though? I'll need to read it before we can look at where we are now within the hierarchy. It does say that there was no difference with the 2mm heel skive compared to no skive; do you still make devices with 2mm heel skives in light of this evidence? If so, why?

There are many reasons why a podiatrist might want to use a technique. One is that they have a vested interest in it of some form or another. Equally there are many reasons why a clinician might observe what they believe are positive outcomes with a given technique. Yet as scientists what we try uncover is the exact nature and the reason behind those outcomes; are they simply down to placebo effect?

Now take your medial heel skive technique. While you may have theorised based on the known application of mechanical principles that the modification should create a shift in the plantar pressures, you could not say for sure whether it did or not without actually measuring it; which the recent study obviously did. Now, like I said I haven't read the study yet, but does it go on to say why there was a medial shift in plantar pressures in association with the medial heel skive? Was it due to the feet pronating more in association with the modification? This is a common sense answer based on known mechanical principles is it not? Moreover, is the external supination moment increased or decreased in association with a medial heel skive?


What if we ran another study of the medial heel skive technique and noted that 95% of subjects developed peroneal tendonitis in association with the devices? Should we continue to use the modification since it's "based on common sense and Newtonian physics?" "I got evidence that it increases the pressure under the medial heel, but I didn't think it was necessary to do any further testing". But you are injuring your patients. "It's based on common sense and Newtonian physics". But you are injuring your patients, you might want to reconsider your actions. etc

Personally, my ego can live with the fact that my opinion only ranks as "poor" within the hierarchy. I can see how some peoples personalities might make it difficult for them to accept that as fact. However, I would rather trust a well designed controlled trial than what someone else might view as common-sense. Here take this tablet, it's common sense that it should work. Have you tested to see if there are any side-effects? No not yet, but it's based on sound pharmaceutical principles.... just like thalidomide was. Err no thanks. :drinks

 

Actually what the study you cited showed Kevin was that despite common sense and an under pinning knowledge of Newtonian mechanics which might have suggested otherwise, the 2mm skive didn't actually make a significant difference to the pressure. So here we have an example of science perhaps questioning personal opinion. Who is it that sells those prefabricated orthoses with a 2mm heel skive in them?

 

I realised that the study you cited was just an abstract from an oral presentation, so there is no more to read- shame.

Found them here http://langergrp.com/rx-skive-p-1249.html

I remembered this had come up before and found the thread here: http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=4160&page=2
post no's. 48-50

Now this is the interesting bit. The study you cited Kevin revealed no significant change in the pressure in association with a 2mm heel skive. We know that because some research was done rather than us relying only on expert opinion and the "common sense application of Newtonian mechanics". Which is a good job because you'd previously said that you:

When actually we now know (thanks to the study that you cited) that the kinetics are pretty much unaltered by the addition of a 2mm heel skive, which is basically what was being marketed by Ray Anthony at the time- a prefabricated device with a 2mm heel skive.

So there we have an excellent example of where the expert opinion has been demonstrated to be incorrect or at least questionable. Your expert opinion at the time appears to suggest you believed that the 2mm heel skive product being marketed by Ray should result in a medial shift of reaction forces (it may do, but not because of the 2mm heel skive within it); research carried out 4 years later shows that this opinion could be incorrect. Viz. the expert opinion may be wrong. This is why expert opinion only ranks as poor on the evidence hierarchy because it is just untested opinion. When such opinion is tested it is sometimes demonstrated to be erroneous. Which is why we need a hierarchy of evidence- Q.E.D.

Indeed, we also now have at least one published paper which says that a medial shift in ground reaction force doesn't necessarily equate to an increase in supination moment. We know that because of common sense and the sound application of Newtonian mechanics. Funny how common sense changes with time and how what we thought was the sound application of Newtonian mechanics a few years ago, might not be what we think of as sound today. But since you are one of the experts who's opinions formed that paper, we'll put that down to evolution in thought processes and understanding. :drinks