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Plantar fasciitis and plantar pressures

Discussion in 'Biomechanics, Sports and Foot orthoses' started by NewsBot, Nov 7, 2009.

  1. NewsBot

    NewsBot The Admin that posts the news.


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    Comparative trial of the foot pressure patterns between corrective orthotics,formthotics, bone spur pads and flat insoles in patients with chronic plantar fasciitis.
    Chia KK, Suresh S, Kuah A, Ong JL, Phua JM, Seah AL.
    Ann Acad Med Singapore. 2009 Oct;38(10):869-75.
  2. Bruce Williams

    Bruce Williams Well-Known Member

    I'll say two things here; 1) can anyone post the PDF on this paper please?,
    2) rarely does a decrease in pressure mean any thing in this
    patient population. Timing, in my experience, is a much more important factor
    in determining whether any treatment will be beneficial.
  3. I too would like to read the full paper.

    Timing in terms of what?
  4. Bruce Williams

    Bruce Williams Well-Known Member

    you use f-scan and know what I personally am refering to as we
    have discussed this many times.

    Let's read the paper and then discuss from there.
  5. Asher

    Asher Well-Known Member

    Hello Bruce,

    I use FScan but I don't know precisely what you are referring to. Would you mind elaborating for me?

  6. Craig Payne

    Craig Payne Moderator

    attached -- I can only leave it here for a day or two..

    Attached Files:

  7. Bruce Williams

    Bruce Williams Well-Known Member

    Thanks Craig! Will give it a look see today.
  8. Bruce Williams

    Bruce Williams Well-Known Member

    Ok, read it thru once quickly now.

    First this was a static study and focused on pressures primarily.

    I admit I don't understand the calculation of the power that they did and hope that Simon or someone else can explain that for me.

    I can see that this discussion may verge into compressive vs tensile causes of PF as others have before. I'm not convinced that tensile forces are not the primary cause here, but I've changed my opinions before and will surely do so again when thoroughly convinced.

    My comments re: timing relate to the fact that with in-shoe pressure, using F-Scan anyway, you can box out the heel and forefoot and compare the F/T loading curves of those regions.

    In my experience, eliminating the platueas or stoppage of motion in those regions will usually eliminate the complaints of the patients with PF pain.

    This could I suppose be related to compressive as well as tensile forces, but as yet I don't understand the differences or potential relatinships to make a final judgement myself.

    cheers and thanks for the post Craig!
  9. Bruce, I think what they were doing is basically along the lines of this- http://en.wikipedia.org/wiki/Signal-to-noise_ratio

    To clean up the f-scan data?

    I agree with Bruce. There are a number of limitations in this study design, not least their use of static analysis.
  10. Bruce Williams

    Bruce Williams Well-Known Member

    Thanks for the link Simon.

    I was also wondering if they used only one device on a foot at a time? Did anyone else get that impression from the paper? I wish that the journal people would see this issue more often and ask the authors to make a definitive statement on how they gathered their data. pet peeve on my end.

    Asher, if you have questions on the F/T data please ask. I know you posted the cases from Tekscan a month or so ago. I did not respond on that and apologize. we can go over that here or in that link, if you direct me to it please, if you like.

  11. Mart

    Mart Well-Known Member

    I am a bit confused by the intent of this paper. Most of the discussion suggests to me that that the goal is, as Bruce suggested, to shine some light on compression at point of maximum tenderness.

    the study states

    “They were then asked to localise the pain they
    experience. The location of the pain was correlated with
    the high-pressure zones shown on the pressure map. To
    minimise bias, patients were not informed of the specific area
    of interest in the pressure measurements and were instructed
    to adopt the most natural stance when measurements were
    taken. ………………….
    The foot pressure scans were converted to greyscale and
    cropped down to the fixed area in the heel. The cropped
    images were processed in MATLAB where Fast Fourier
    Transformation (FFT) was performed. This shows the
    relative strengths of frequencies in the image data and the
    highest frequency power were selected for analysis. The
    power ratio (proportion of the highest frequency power to
    the total power of the image) was one of the parameters

    I don’t understand what data was processed in MAtlab, what was point of grey scale? was the analysis of rate of change in pixilation of image or ??

    My assumption is that this was the only analysis done to point of maximum tenderness “mask”.

    The paper states

    “This is particularly important in view of the
    current finding of elevated rearfoot pressure in subjects with
    plantar fasciitis with forces in the rearfoot approaching that
    of peak total pressure.”

    Would anyone think that for standing with bipedal resting stance position this would be unexpected? I would anticipate (not withstanding pain avoidance) that the peak pressure ratio, forefoot/rearfoot would be mostly a function of balance (speed of response to perturbation) if barefoot and with shod foot also a function of heel height. I am not sure of the point that is being made by this statement.

    My assumption is that the study was done static to eliminate variables of effect of lower limb contact angle (step length), body velocity, between trials and individuals.

    I would have been interested to have looked at the data of peak pressures at masked point of maximum tenderness symptomatic vs normal. I have thought about trying that as an experiment but it may be confounded by variability of plantar fibro-fatty pad compliance. If the compliance could be estimated however that would interesting.

    Food for thought because I believe that chronic plantar fasciosis may be a “normal” adaptive response to increased compression stress in addition to or rather than tensile stress.



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  12. Bruce Williams

    Bruce Williams Well-Known Member


    just wondering why you think that it is more compression than tensile?
    just curiously looking for a line of reasoning!;)

  13. Craig Payne

    Craig Payne Moderator

  14. I guess the power ratio was white/ grey versus black- hence the transform to greyscale. I am guessing though.

    One of my biggest issues is that they used in-shoe pressure measurement over surfaces of vastly different geometry.
  15. Mart

    Mart Well-Known Member

    Yes . . . Craigs pointer is a major influence on my current belief. I guess it is plausible that an enthesite might be an adaptive responce to tensile loading initialy and then develop compressive adaptive responce (trabecular allignment) subsequent to morphological effects on GRFs.

    Also I feel that it is likely that, given the microscopic structure and the physiological responces to stress, for the mechanical elements of the Pl Fascia to compressive and tensile forces are inextricably connected particularly if thinking about pain response to stresses. Although FEA modeling indicated point of max tensile stress at enthesis, although to knowledge similar modelling of compressive forces has not been published, it would be suprising not to see a similar picture.

    If I think about inate "evolutionary intelligence" of repair/adapation of the fascia, the changes suggested by inferences from US, MRI and histology, though limited and debatable are equally consitent to compressive and tensile injury. However the enthesiste evidence for trabecullar alignment tips the ballance for me currently.



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