Welcome to the Podiatry Arena forums

You are currently viewing our podiatry forum as a guest which gives you limited access to view all podiatry discussions and access our other features. By joining our free global community of Podiatrists and other interested foot health care professionals you will have access to post podiatry topics (answer and ask questions), communicate privately with other members, upload content, view attachments, receive a weekly email update of new discussions, access other special features. Registered users do not get displayed the advertisements in posted messages. Registration is fast, simple and absolutely free so please, join our global Podiatry community today!

  1. Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
Dismiss Notice
Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
Dismiss Notice
Have you liked us on Facebook to get our updates? Please do. Click here for our Facebook page.
Dismiss Notice
Do you get the weekly newsletter that Podiatry Arena sends out to update everybody? If not, click here to organise this.

Article on casting from Podiatry Today

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Simon Spooner, Jun 27, 2014.

  1. Tell me yours, and I tell you mine...;)

    Suffice to say: casts aren't feet; casts are not foot orthoses; foot orthoses are not feet; feet can move on foot orthoses viz. foot orthoses don't hold the foot in a certain position; the midtarsal joint doesn't "lock"; the midtarsal joint doesn't have oblique and longitudinal axes; the world of foot orthoses and biomechanics has moved on since Merton Root... shall I continue?

    A cast provides an initial shape, nothing more nor less. This initial shape may or may not go on to determine the shape of the orthosis at the foot/orthosis interface. More often than not, plaster is added and taken away and the shape of the orthoses bears little resemblance to the intial cast. The notion that there are right and wrong ways to cast the foot are as daft as the idea that there is one all encompasing ideal alignment of the foot. One can start with a cube of plaster and still design an efficacious foot orthoses with no cast ever being taken. Moreover, we now understand how foot orthoses generate reaction forces, and the shape at the foot/orthosis interface is only one factor in this.

    In my opinion, many of the views expressed in this article appear dated, biased and lacking in appreciation for how foot orthoses work. Oh, and there are a couple of cheap shot's in there too.
  2. I rarely cast for functional devices and more often than not use a simple base plate such as the Rx Instant and add mods. Casting these days usually for total contact insoles for direct pressure relief for specific pathology.
  3. I agree with you completely, Simon.:drinks

    I know the people involved in these debates very well. Their opinions don't surprise me since I've heard their opinions many times before.

    Unfortunately, for some podiatrists and their opinions on foot orthoses and foot biomechanics, the goal seems to be to first honor the memory of Mert Root and second try and explain why doing things the way Mert Root did them is somehow better than what we currently teach today. That is why I have basically given up on the hope that I can teach older US podiatrists anything new about foot orthoses or foot biomechanics since they are too deeply entrenched into the Root-based ideas of the past. I do, however, still enjoy teaching young podiatrists since they do not seem be stuck in the sticky mud of past podiatric biomechanics dogma.

    The way forward for our profession is not to continually try and explain why the things Mert Root did and thought are always better than what we do and teach today. Rather, applying Newton's Laws and basic engineering principles to foot orthoses and foot and lower extremity biomechanics is the way forward for our profession. Period.
  4. Round and round we go where it stops no one knows.

    ok I admit I stopped reading after the 1st page.

    I have my own form of casting ideas, I make my own devices I do all the modifications. Not sure I could ever get a lab to make my devices again, but when will the endless debate end.

    I do wonder if the next generation of US pods will still be having the to Root or not Root debate.

    Or will biomechanical learning and discussion be dead.
  5. I agree, Mike. We hear about the slow death of biomechanics in US podiatry. The article in this thread exemplifies some of the problems with US podiatric biomechanics education. As an outsider who frequently looks in, it is easy to see why young US podiatrists might be turned off when such dated and dogmatic views are being expressed by those that are suppossed to be "leaders" in the subject there. And heaven help you if you are from "the East coast"...
  6. I agree with Daryl on this though:
    "Failure of schools to actively recruit the brightest biomechanical minds for teaching. Dr. Phillips acknowledges that there are “extremely dedicated people” teaching biomechanics at the schools but there are far too few of them. He says few if any funds are dedicated to biomechanics research at the schools and faculty are not well rewarded for producing strong biomechanics research."

    I can do that, giz a job. Go on giz it.

    This is my favourite from Yosser:
  7. RobinP

    RobinP Well-Known Member

    Didn't get beyond page 2. I cried a little bit when I read some parts
  8. Dieter Fellner

    Dieter Fellner Well-Known Member

    All of the above is true. In England I had the luxury of an in-house orthotics lab equipped with excellent technicians. And the freedom to pop down to the lab and make or modify as necessary and ad infinitum.

    American practice is heavily shaped and influenced by the health care market. But consider this: Podiatrists are, for the most part, self employed. The US does not have the NHS. And no insurance carrier (there are hundreds) will cover payment for 'foot orthoses'. A great proportion of patients will be *very* reluctant to part with $$$ for an 'out-of-pocket' expense. Even when efficacy can be predicted, and that is no guarantee. For the most part, the US Podiatrist must be able to turn over patients - it's a numbers game. Bills must be paid, a living must be earned.

    Dr. D. Philips, in the article laments about the fact there is a much higher requirement for surgical logging than biomechanics. That should not be a surprise now, really? Surgery can inflict on a patient some very serious harm, potentially causing morbidity & mortality.... and law suits. Poor biomechanics might possibly hurt the wallet.

    Residency programs are almost exclusively surgical residency programs. It should be no surprise the focus in residency is on medicine and surgery. I am, in no way, defending this reality. But it is what it is. Many hospitals require a 3-year PMSR program. A 3-year program is also a requirement for Board Certification. And, in the event of a law suit (likely because of frivolous litigation) the prosecution invariably inquires of the defendant if he/she has such a qualification.

    All of my co-residents appreciate the role and value of biomechanics. When insurance carriers will not meet the fees, it is an economic reality, in real world Podiatry, to focus on those aspects of clinical practice that can help pay the bills. Our grandmasters, such as Dr. Kirby, have had decades to lay a solid foundation for their practice. In this ever changing political climate, is it still possible to follow his example? The sole practitioner appears to be a species now gravely at risk of extinction.

    While I too, once was critical, the reality here, in the US, is a complex set of multiple factors that shape and mold the practices of the contemporary Podiatrist.
  9. Dieter Fellner

    Dieter Fellner Well-Known Member

  10. Bill Bird

    Bill Bird Active Member

    Thank you Simon. Nicely put. I might even copy that and paste it on my wall. This quote struck me as that is just what I do when carving a last out of wood, not plaster.
    This quote struck me as that is just what I do when carving a last out of wood, not plaster. The insole of the shoe then becomes the footbed and the posting is done with the heel block.
  11. toomoon

    toomoon Well-Known Member

    I completely agree Simon.. my only comment, and this is basically for anyone just starting out.. is that there are actually some rules for casting, and it is important to know how to execute this correctly. It is super easy to induce errors, so it pays to get good at it if that is the way you wish to go..
  12. I agree, Simon B. I believe it does matter how you cast a foot for orthoses and it should be done with great precision to ensure the best results for patients, otherwise over-the-counter foot orthoses would work just as well for our patients as do custom foot orthoses.

    However, this doesn't mean that other methods of obtaining a three dimensional image of the foot can not work. What it does mean is that consistency in obtaining this three dimensional plantar foot image, whether it is with a supine or prone plaster cast, a foam box, a contact digitizer or with an optical scanner, is one of the keys to obtaining consistent therapeutic success with foot orthoses.
  13. Bill Bird

    Bill Bird Active Member

    I use a minimum of four inputs, chosen from a possible range of; Casting, (foam box or prone slipper casts) photographs, weight bearing ink impressions, computer gait analysis, palpation of tissues and traditional last making drafts. I agree that they all have to be done to a consistent standard, and yes I do capture the foot in a position I believe to give the most useful information which does originate from how I was taught in the 70s and 80s based on root mechanics.
    What I liked about Simon Bs thinking is he seems to be suggesting that it comes down to a synthesis between intuition based on years of experience and a wide range of observations and measurements of the totally unique individual I am dealing with in any particular case.
    With regards to teaching, I can see no other way to teach young inexperienced students other than following a carefully worked out accurate routine, based on the least inaccurate theory currently available. How else are they to gain the experience? The only other way is to spend thousands of hours working with a mentor.
  14. gez

    gez Member

    Many of you have alluded to the fact you look for certain things when casting a foot to make orthotics, as Simon said "there are some rules for casting".
    Do you mind if I ask what you look for when casting, how you determine if the cast is suitable for what you are trying to achieve with an orthoitc.

    I remember a youtube video from years ago called something like the 10 determinants of casting which was very based around a root theory. I'm curious how this will have changed with some of the newer ideas behind how foot orthotics work.

    Thanks in advance Gez
  15. Petcu Daniel

    Petcu Daniel Well-Known Member

    "A shape is the form of an object or its external boundary, outline, or external surface, as opposed to other properties such as color, texture, material composition." http://en.wikipedia.org/wiki/Shape

    Apart of any method of cast taking, I'm thinking that "information" is another property of an object [in this case the cast].
    The question is which useful "information" could [or should] contain the "shape" of a cast ?

  16. Bill Bird

    Bill Bird Active Member

    It depends what the pathology of the patient that you are trying to help with, Gez. If you are dealing with more or less healthy people who want to improve their gait a little, then there are formulas to follow. The majority of people I see are dealing with a significant pathology.
    If it's CMT for instance, I cast to anticipate bringing the ground reaction forces up through the shoe to compensate for the perineal muscular atrophy.
    If it is a ruptured or very weak PT tendon I will do the same only the opposite way around. Is it a 1st, 2nd or 3rd degree pronation deformity? If it's a 3rd degree I sense how much I can push back and where to do it and where to not do it because as the plaster sets, I can feel the soft and hard plantar tissues very accurately.
    If there is a significant windlass effect that's causing a problem I will be lifting just behind the 2,3,4th met heads, but dropping or subsequently adding material to the 1st met head to release the medial band at heel lift.
    These are all really important elements to capture and they will be relatively unique to the individual. There are dozens of such conditions and even two people with the same condition will differ in many ways with respect to what is needed. Work with and listen to people who have been doing it for a long time. When a patient presents, google the condition and study all the aspects of it. It has never been easier to do that. Then think through what could help. In some ways it is common sense once you have understood the underlying stresses and weaknesses.

Share This Page