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. Everything that you are ever going to want to know about running shoes: Running Shoes Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
  2. Have you considered the Critical Thinking and Skeptical Boot Camp, for taking it to the next level? See here for more.
    Dismiss Notice
  3. 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.

Research parameters for evaluating casting methods

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Redman, Jan 27, 2009.

  1. Redman

    Redman Member

    Members do not see these Ads. Sign Up.
    If a clinician has a repeatable and reliable method of casting for the manufacture of orthotics, what would be the best research parameters, to prove or disprove whether the method is valid?

  2. Re: Research Parameters

    Depends what you mean by valid.

    That link seems to be unstable so:
    In psychology, validity has two distinct fields of application. The first involves test validity, a concept that has evolved with the field of psychometrics but which textbooks still commonly gloss over in explaining that it is the degree to which a test measures what it was designed to measure. The second involves research design. Here the term refers to the degree to which a study supports the intended conclusion drawn from the results. In the Campbellian tradition, this latter sense divides into four aspects: support for the conclusion that the causal variable caused the effect variable in the specific study (internal validity), support that the same effect generalizes to the population from which the sample was drawn (statistical conclusion validity), support for the intended interpretation of the variables (construct validity), and support for the generalization of the results beyond the studied population (external validity).
    Contents [hide]
    1 Introduction
    2 Types
    2.1 Internal validity
    2.2 External validity
    2.3 Ecological validity
    2.4 Population validity
    2.5 Construct validity
    2.6 Intentional validity
    2.7 Representation validity or translation validity
    2.8 Content validity
    2.9 Face validity
    2.10 Observation validity
    2.11 Criterion validity
    2.11.1 Concurrent validity
    2.11.2 Predictive validity
    2.12 Convergent validity
    2.13 Discriminant validity
    2.14 Social validity
    3 Statistical conclusion validity
    3.1 Factors jeopardizing validity
    3.1.1 internal validity
    3.1.2 external validity
    4 See also
    5 External links

    An early definition of test validity identified it with the degree of correlation between the test and a criterion. Under this definition, one can show that reliability of the test and the criterion places an upper limit on the possible correlation between them (the so-called validity coefficient). Intuitively, this reflects the fact that reliability involves freedom from random error and random errors do not correlate with one another. Thus, the less random error in the variables, the higher the possible correlation between them. Under these definitions, a test cannot have high validity unless it also has high reliability. However, the concept of validity has expanded substantially beyond this early definition and the classical relationship between reliability and validity need not hold for alternative conceptions of reliability and validity. Within classical test theory, predictive or concurrent validity (correlation between the predictor and the predicted) cannot exceed the square root of the correlation between two versions of the same measure — that is, reliability limits validity.
    Test validity can be assessed in a number of ways and thorough test validation typically involves more than one line of evidence in support of the validity of an assessment method (e.g. structured interview, personality survey, etc). The current Standards for Educational and Psychological Measurement follow Samuel Messick in discussing various types of validity evidence for a single summative validity judgment. These include construct related evidence, content related evidence, and criterion related evidence which breaks down into two subtypes (concurrent and predictive) according to the timing of the data collection.
    Construct related evidence involves the empirical and theoretical support for the interpretation of the construct. Such lines of evidence include statistical analyses of the internal structure of the test including the relationships between responses to different test items. They also include relationships between the test and measures of other constructs. As currently understood, construct validity is not distinct from the support for the substantive theory of the construct that the test is designed to measure. As such, experiments designed to reveal aspects of the causal role of the construct also contribute to construct validity evidence.
    Content related evidence involves the degree to which the content of the test matches a content domain associated with the construct. For example, a test of the ability to add two-digit numbers should cover the full range of combinations of digits. A test with only one-digit numbers, or only even numbers, would not have good coverage of the content domain. Content related evidence typically involves subject matter experts (SME's) evaluating test items against the test specifications.
    Criterion related evidence involves the correlation between the test and a criterion variable (or variables) taken as representative of the construct. For example, employee selection tests are often validated against measures of job performance. Measures of risk of recidivism among those convicted of a crime can be validated against measures of recidivism. If the test data and criterion data are collected at the same time, this is referred to as concurrent validity evidence. If the test data is collected first in order to predict criterion data collected at a later point in time, then this is referred to as predictive validity evidence.
    Face validity is an estimate of whether a test appears to measure a certain criterion; it does not guarantee that the test actually measures phenomena in that domain. Indeed, when a test is subject to faking (malingering), low face validity might make the test more valid.
    In contrast to test validity, assessment of the validity of a research design generally does not involve data collection or statistical analysis but rather evaluation of the design in relation to the desired conclusion on the basis of prevailing standards and theory of research design.

    [edit]Internal validity
    Internal validity is an inductive estimate of the degree to which conclusions about causes of relations are likely to be true, in view of the measures used, the research setting, and the whole research design. Good experimental techniques in which the effect of an independent variable on a dependent variable is studied under highly controlled conditions, usually allow for higher degrees of internal validity than, for example, single-case designs.
    [edit]External validity
    The issue of External validity concerns the question to what extent one may safely generalize the (internally valid) causal inference (a) from the sample studied to the defined target population and (b) to other populations (i.e. across time and space).
    [edit]Ecological validity
    This issue is closely related to external validity and covers the question to which degree your experimental findings mirror what you can observe in the real world (ecology= science of interaction between organism and its environment). Ecological validity is whether the results can be applied to real life situations. Typically in science, you have two domains of research: Passive-observational and active-experimental. The purpose of experimental designs is to test causality, so that you can infer A causes B or B causes A. But sometimes, ethical and/or methological restrictions prevent you from conducting an experiment (e.g. how does isolation influence a child's cognitive functioning?) Then you can still do research, but it's not causal, it's correlational, A occurs together with B. Both techniques have their strengths and weaknesses. To get an experimental design you have to control for all interfering variables. That's why you conduct your experiment in a laboratory setting. While gaining internal validity (excluding interfering variables by keeping them constant) you lose ecological validity because you establish an artificial lab setting. On the other hand with observational research you can't control for interfering variables (low internal validity) but you can measure in the natural (ecological) environment, thus at the place where behavior occurs.
    [edit]Population validity
    [edit]Construct validity
    Construct validity refers to the totality of evidence about whether a particular operationalization of a construct adequately represents what is intended by theoretical account of the construct being measured. (Demonstrate an element is valid by relating it to another element that is supposively valid.) There are two approaches to construct validity- sometimes referred to as 'convergent validity' and 'divergent validity'.
    [edit]Intentional validity
    Validity proves no bias
    [edit]Representation validity or translation validity
    [edit]Content validity
    This is a non-statistical type of validity that involves “the systematic examination of the test content to determine whether it covers a representative sample of the behaviour domain to be measured” (Anatasi & Urbina, 1997 p114).
    A test has content validity built into it by careful selection of which items to include (Anatasi & Urbina, 1997). Items are chosen so that they comply with the test specification which is drawn up through a thorough examination of the subject domain. Foxcraft et al (2004, p. 49) note that by using a panel of experts to review the test specifications and the selection of items the content validity of a test can be improved. The experts will be able to review the items and comment on whether the items cover a representative sample of the behaviour domain.
    [edit]Face validity
    Face validity is very closely related to content validity. While content validity depends on a theoretical basis for assuming if a test is assessing all domains of a certain criterion (e.g. does assessing addition skills yield in a good measure for mathematical skills? - To answer this you have to know, what different kinds of arithmetic skills mathematical skills include ) face validity relates to whether a test appears to be a good measure or not. This judgment is made on the "face" of the test, thus it can also be judged by the amateur.
    [edit]Observation validity
    [edit]Criterion validity
    Criterion-related validity reflects the success of measures used for prediction or estimation. There are two types of criterion-related validity: Concurrent and predictive validity. A good example of criterion-related validity is in the validation of employee selection tests; in this case scores on a test or battery of tests is correlated with employee performance scores.
    [edit]Concurrent validity
    Concurrent validity refers to the degree to which the operationalization correlates with other measures of the same construct that are measured at the same time. Going back to the selection test example, this would mean that the tests are administered to current employees and then correlated with their scores on performance reviews.
    [edit]Predictive validity
    Predictive validity refers to the degree to which the operationalization can predict (or correlate with) with other measures of the same construct that are measured at some time in the future. Again, with the selection test example, this would mean that the tests are administered to applicants, all applicants are hired, their performance is reviewed at a later time, and then their scores on the two measures are correlated.
    [edit]Convergent validity
    Convergent validity refers to the degree to which a measure is correlated with other measures that it is theoretically predicted to correlate with.
    [edit]Discriminant validity
    Discriminant validity describes the degree to which the operationalization does not correlate with other operationalizations that it theoretically should not correlated with.
    [edit]Social validity
    [edit]Statistical conclusion validity

    [edit]Factors jeopardizing validity
    Campbell and Stanley (1963) define internal validity as the basic requirements for an experiment to be interpretable — did the experiment make a difference in this instance? External validity addresses the question of generalizability — to whom can we generalize this experiment's findings?
    [edit]internal validity
    Eight extraneous variables can interfere with internal validity:
    1. History, the specific events occurring between the first and second measurements in addition to the experimental variables
    2. Maturation, processes within the participants as a function of the passage of time (not specific to particular events), e.g., growing older, hungrier, more tired, and so on.
    3. Testing, the effects of taking a test upon the scores of a second testing.
    4. Instrumentation, changes in calibration of a measurement tool or changes in the observers or scorers may produce changes in the obtained measurements.
    5. Statistical regression, operating where groups have been selected on the basis of their extreme scores.
    6. Selection, biases resulting from differential selection of respondents for the comparison groups.
    7. Experimental mortality, or differential loss of respondents from the comparison groups.
    8. Selection-maturation interaction, etc. e.g., in multiple-group quasi-experimental designs
    [edit]external validity
    Four factors jeopardizing external validity or representativeness are:
    9. Reactive or interaction effect of testing, a pretest might increase the scores on a posttest
    10. Interaction effects of selection biases and the experimental variable.
    11. Reactive effects of experimental arrangements, which would preclude generalization about the effect of the experimental variable upon persons being exposed to it in non-experimental settings
    12. Multiple-treatment interference, where effects of earlier treatments are not erasable.
    [edit]See also

    Validity (logic)
    [edit]External links

    Cronbach and Meehl, 1955, Construct Validity in Psychological Tests
    Categories: Philosophy of science | Psychometrics | Educational psychology | Logic and statistics
    Last edited: Jan 27, 2009
  3. David Smith

    David Smith Well-Known Member

    Re: Research Parameters

    I guess you mean 'if a clinician thinks he has a repeatable and reliable method of casting'

    Reasonable, reliable, repeatable. Valid

    How I would interpret these criteria:

    Reasonable = Are the Theory, premise and assumptions made ones that could be applied in a logical and rational manner to the particular Research. E.G. Do they follow convention (Inductive reasoning from citations) or have you just plucked them from thin air. Can you argue from deductive reasoning that these criteria are valid?

    Reliable = Was the research constructed in such a way that the results are reliable. E.G. did you exclude as many unknown variables as possible? was the intervention likely to have changed the results? How do they compare to other similar research?

    Repeatable = If this research was done several times is it likely that each set of results is similar?
    How similar are they and is the range of difference acceptable and reasonable.

    Valid = Does the research fulfil the above criteria?

    From a purely academic point of view that should answer your question. If you wish to see how accurate, precise and repeatable your casting technique is or how repeatable and reliable it is compared to someone else's then, choose any parameters you like. It will have no bearing on clinical outcome.

    However I suspect that by the term 'Valid' you mean that - it is one that is most likely to produce good positive outcomes in the clinical situation? In that case you need to compare casting techniques to outcomes.

    I would contend however that how ever much the statistical data favoured one type of casting method, when it comes to the individual patient the statistics are not very useful. You need to cast for that individual, which maybe completely different from anyone else but exactly right for them.

    One must remember that especially in medical and paramedical research statistical data is not valid for the individual since statistics are indications of probability within large groups.

    If you were making nuts and bolts and you wanted statistical data to show which machine produced the most precise, reliable and repeatable product, then it would be reasonable and valid to use that data to make your choice of machine since all your nuts and bolts are the same. Indeed it is required that they are the same within a small tolerance and each and every nut and bolt fit each other perfectly.

    Humans are not identical or even similar and so how can you expect one process to be the best for any individual.

    Having said that - for the large organisation like the NHS, who wish to standardise treatment for the sake of financial considerations the statistical data is useful since this will indicate that for their large group of patients a certain intervention gives the best chance of a positive outcome. It's like betting only on the favourites at the the Horse track without considering form and conditions.

    Cheers Dave
  4. Re: Research Parameters

    Use Mz twins with identical foot pathology, cast one twin using one method and another using another.

    P.S. Anyone else smell Ed here?
  5. Re: Research Parameters


    I would agree with dave here. There is a gulf of difference between repeatable and valid. Repeatable just means consistent. This does not make it valid. So I would say your question is actually two questions.

    Testing for repeatability is straightfoward enough and there are several studies around on pop and foam which have attempted to do this. Validity is much harder because it would have to be linked to outcome measures. To do this one would need to carry out a double blinded comparison rct where once the cast is taken neither the person issueing the insole nor the patient knew which method had been used. If the same prescription casted both ways produced equal or better outcomes in such a trial I would consider the method valid.

    Mind you let's not get too caught up in research fever, lest the pragmatic gods of applied science wax wroth! In the absence of inductive evidence I am always willing to consider new techniques based on solid deductive reasoning, particularly if it can then be backed with some positive empiricism.

    Don't be coy. Lets hear it! I'm guessing you think it is good based on experience and reasoning. The latter is highly prized here. But be warned, if it IS MASS you're talking about we've been around that stump faaaaar to often.:eek:

  6. Re: Research Parameters

    Fee, fi, fo, fum.....I smell the blood of a MassCast-man!!:rolleyes:
  7. Redman

    Redman Member

    Re: Research Parameters

    No, not MassCast-man.

    How do we best scientifically evaluate and compare different orthotic devices effect on function.

    Sheldon Redman
  8. David Smith

    David Smith Well-Known Member

    Re: Research Parameters

    In my opinion there is no magic bullet.

    You use your skill and experience and education to prescribe and cast the right orthoses for the patient. You know you're getting it right when they keep coming back with positive results.

    EG a UCLB might in the research setting give more consistent changes in STJ angle than an EVA root style orthosis. Does this = improved outcomes? Only those that require this change need the UCBL and so it is down to the clinician to decide when this is.

  9. Re: Research Parameters


    I'm struggling to see where you are coming from. Are you looking for a research protocol? Are you speaking of different orthotics as in different devices? Different prescriptions? Different Casting techniques? Different modifications? Are we speaking of comparing kinetic / kinematic effects or patient outcomes? There are so many potential variables to what you are asking!

    It might help you to get the answers you seek if you can either be more precise with your questions or give us some idea of where you are coming from. Otherwise i fear you will not get an answer which will satisfy you.


    (PS, don't mind the giant at the top of the beanstalk ;), He's really very friendly and almost never eats people.)
  10. Re: Research Parameters

    I suspect Sheldon wants to know if one casting technique is "better than another". The questions, as intimated by me learned colleagues, then become: better at what? And better for what? And for whom?

    Methodological issues here are multiple, not least we have the problem of comparing like with like. Custom devices are unique and cannot be compared across individuals within research populations, since the mechanical effects that the orthoses have are dependent upon their physical characteristics, the subjects themselves and their activities during the study period. Research that attempts to do this is, frankly, a whole load of cack. I still await a counter argument to this conjecture and for the guys from planet X to get back....

    I won't hold my breath; I shall expectorate.

    I've had it with blondes- The Cud Band http://www.last.fm/music/CUD/_/I've Had It With Blondes

    I was a teenage stamp collector,
    I'd lay on my back and you'd stamp on my face,
    And in the towns where I live,
    There's stamp collectors all over the place.

    I never said your dress was saggy,
    That I thought your tights were baggy,
    But I kept in mind,
    Your intellect I felt in kind.

    I know you've already been told,
    But let me say it again,
    Let me say it one more time,
    Things Get Worse When You Get Older.

    This might sound like a whole load of cack,
    But just wait till the guys from Planet X get back,
    7AM July 5th 1998,
    But don't hold your breath expectorate.

    BTW: 7AM July 5th 1998 - http://www.subgenius.com/bigfist/answers/x-day/X0001_DATE.TXT.html

    Don't you just love chat rooms...
    Last edited: Jan 28, 2009
  11. Redman

    Redman Member

    Re: Research Parameters

    As a profession how can it progress if we can't compare orthotic casting and prescription techniques??

    One therapist who see's 10 different professionals will have 10 different orthoses, that may or may not work. If we have a fair idea on why orthoses do work then why can't we measure how effective they are comparitively. Are we left as artists with some science and experience only.

    I'm writing because I am interested in what the best minds have to say. We all THINK we are doing the best job and we only know if we are on how our patients respond. We can't say with scientific fact that this orthotic is as usefull as a sockliner and that one is functional. Surely we can measure something that is statistically significant, rate the comfort, reliabilty etc and say this orthotic technique and device is the best for......... rearfoot pronation or navicular drop...etc etc
  12. Re: Research Parameters


    As you can see from the responses generated by your query, your question is not an easy one to answer. To produce an orthosis that works for a patient requires much more than making a cast of a foot by a "valid method", but it obviously is a good first step.

    Are you interested in performing this research yourself, or are you asking more for informational purposes? What type of casting do you use? What type of casting procedures do you hope to study?

    Come on up the beanstalk.....I promise I'll be good.....:cool:

    Attached Files:

  13. vcameron

    vcameron Welcome New Poster

    Re: Research Parameters

    Hello Sheldon,

    In order to investigate validity you have to compare your method to the gold standard. So I think this is the prolem with casting foot orthoses - I am not aware that there is a gold standard. You could perhaps compare your negative cast impressions to the cadcam - this is perhaps the closest there is at the moment to a gold standard that is objective and quantifiable. You could easily look at intra-rater and inter rater reliability to start with.

    Best Wishes
  14. Redman

    Redman Member

    Re: Research Parameters

    Up the beanstalk or entering the Matrix??

    We have more reliabilty and comfort then NWB casting. The negative is in no way modified. The cast is taken in full weightbearing. The rearfoot, medial and lateral midfoot plus forefoot can all be adjusted with vertical, translational and rotational forces once soft tissue slack has been taken up. The 1st ray can be planta flexed. Metatarsal raises can be used whilst casting. Deflections, planta-fascia grooves can be marked exactly where they are. The foot can be supinated and pronated. The heel height, width and transverse plane angle can be adjusted. The joints can be palpated. The force required can be felt. The posture of the foot and lower limb can be seen. The result is a comfortable orthotic that gets great results. It's not perfect but it sure seems better. Would be nice to be able to test if it is compared to every other casting methods/orthotics.

    I don't want to do the research myself. I simply believe I make better orthotics using the FAS compared with NWB methods. Would be nice to prove it.
  15. David Smith

    David Smith Well-Known Member

    Re: Research Parameters


    Exactly! good point well made

  16. JPod

    JPod Member

    Re: Research Parameters

    Surely the problems here are much greater than just the validity and reliability of your method of casting? Even if you could prove, perhaps by comparing your own cast with a cad-cam cast in a repeated-measures type study, that you can turn out an exact replica each time (although surely this misses the point of casting? You could just use off-the-shelf...) there are many more issues you would need to take into account. You state that we know what works and why in orthosis prescription, however there is in fact no gold standard: much evidence is anecdotal and attempts at designing research studies to test exactly what effect a certain prescription has are often flawed. If you could completely standardise your casting method and you wanted to compare the effect of orthoses made using your casts with those made using another cast and if you could say with certianty what aspects of orthotic control were beneficial to the wearer, what effect each modification has on gait parameters and could justify why this occurred then a study would be simple: Collect force, pressure and kinematic data for your own orthosis and another for x number of participants and compare the deviations from your 'gold standard'. If yours results in less deviation from your 'norm' then your orthosis is best. If there is little deviation from the 'norm' for every participant using your orthoses you know they are reliable. However...
  17. Re: Research Parameters


    Great quote. :bang: By the way, what is a FAS? Are you sure it isn't a cousin to MASS? So I smelled a FAS-Cast man, not a MASS-Cast man?:cool:
  18. David Smith

    David Smith Well-Known Member

    Re: Research Parameters


    You promised to be good
    And then you wrote
    And I would like to know as well please Sheldon
    Just an thought - F.A.S. Free Association System. I have an idea, then you make up the first theory that comes into your head and we use it as a design for reliable repeatable casting system. Then we vaguely test it on Pod Arena.

    Now look what you've made me do Kevin:hammer:

    Sorry Sheldon, just a friendly ribbing, all done in the best possible taste - blame Kevin, I'm easily led.

    All the best Dave
  19. Re: Research Parameters

    I meant good in a bad sort of way.;)

    Attached Files:

    Last edited: Jan 29, 2009
  20. Re: Research Parameters

    Now boys. Be nice to the nice man. He's not crossed the line yet (although nudging towards it.;)

    Hey Sheldon

    It has been said that Pod arena is like swimming with the sharks. This is of course a vicious lie, we're all lovely soft kittenish types. However some things can be relied upon to provoke a response. One is to make a claim that your way is better than another without backing it up with anything more than your testimonial.

    You say your way has more "comfort". How was this tested? Against what NWB protocol? Against what type of orthotic? Treating what kind of problem? How many clinicians were involved? You can't just say something is better without something to justify or back your statement up!

    All sounds rather interesting! Certainly something i'd like to hear more about. Please don't be shy, show us this method!


    See my first point. With sincere respect, this sounds like self agrandisement. Who here would say that they make UNcomfortable orthotics with poor results? Are you seeking to impress us or any lay people who wander by?

    Better how? You can't be that vague!

    So You're saying YOU don't want to do the research... but you would like your hypothesis to be proved!? Who do you think is going to do it for you?!

    Some advice. And this holds for any who come with an "innovation"

    1. DON'T say its better than the existing methods unless you have something to back it with! It just P**ses people off. You can't possibly know all of the other methods which are out there. By all means say that your way is good in your experiance. By all means tell us what it is and let us decide its merit for ourselves. But by saying its better you are comparing your way (which we don't know) to a hugely diverse and varied selection of methods (which YOU don't know all of) and expecting it to carry weight!

    2. Don't hedge. You have a new method. You're excited about it. Thats great! Come tell us what it is and if we like the sound of it we'll be excited too! But don't came asking for research parameters then tell us you don't want to do any research! Thats just irritating!

    Come now. Show us the goods.

    What is your method of casting?

    What devices have you been producing with it?

    What is your rationale for why this is better than the method you were using before?

  21. Re: Research Parameters

    I have. And if you think you never have, you either haven't made many pairs of devices or you're kidding yourself. You learn more from these cases than the ones where you get it right first time.
  22. efuller

    efuller MVP

    Re: Research Parameters

    One of the many definitions of validity has to relate to the idea that plantar flexing a ray or supinating the STJ when taking an impression will lead the foot attaining the same position when standing on an orthosis made from that impression. This concept is not valid.

    Many other points you made can also be done in pop casts and can be incorporated in orthoses made from those casts.

    Also, those modifcations will increase the variables in a study. Another question to ask is which casting method is most often succesful without any modifications. Still another question to ask, if you took a bunch of different casts of the same foot, but altered the prescription to the pathology (e.g. medial heel skive with PT dysfunction) would that be better than a consistant cast without the change in prescription.

    I have worn 2 different MASS casted orthoses and both were extremely painful. My neutral suspension casted devices relieve my hallux limitus pain just fine. Adding a reverse Morton's extension makes them better. No one method will work for all feet. Knowing when to alter your basic technique is important.


  23. Re: Research Parameters

    You're being pedantic Simon :-0 ;-) you know what I meant. We've all MADE individual devices which did'nt work. However I was speaking as sheldon was in terms of broad claims of types of orthotics in the present future tense not of individual failiure in the past tense.

    I would agree that learning from failiures is a vital part of developing as a clinician.

  24. Steve The Footman

    Steve The Footman Active Member

    Re: Research Parameters

    Perhaps we need a research study with a different device or casting method made with each foot. Then the subject could say what foot felt best. Of course few people are symmetrical so you would have to eliminate everyone with the slightest deformity. That would leave about 5% of people still. You could then find some athletes with bilateral problems and see how it works with them.

    In the end there are so many variables that validity becomes a near impossibility.
  25. Redman

    Redman Member

    Re: Research Parameters

    So Its official....The Natives are Restless, the sharks are circling, I'm up the stalk and in the matrix....

    Ask C. Payne about the studies for reliabilty and comfort.

    FAS....c'mon gentlemen.........."you can do it"

    I'm a clinician. I read the research, not do it. Plus how much credence would you give a paper titled: FWB casted orthoses better then the rest. Author S. Redman

    I would like to remain impartial. I'll simply pay for it to be done....plus a new car to anyone who proves it......

    Force, pressure, kinematic comparison data sounds good. We have to start somewhere...

    Rational? LOGIC, absolutely no positive cast modification, using force in 3 planes to manipulate the foot and lower limb, directing the force exactly where you want, soft tissues accounted for.

    When a foot is manipulated using the FAS at first nothing changes to the eye or feel as the soft tissue slack is taken up, then resistence is met. The supination force continues to be added. The forefoot is everted to plantaplane the MLA is adjusted, again with a supination force until the weight of the rearfoot correction and midfoot correction is balanced. There is a point where the supination force required is maximal and also a point when it becomes very easy to manipulate the foot. This point is not necessarly a visual neutral position but my assumption is that this point is where the STJA and the MTJA are in equilibrium. Thats what I cast too for most cases. As the cast is taken whilst standing on a thickish but soft EVA foot bed and the shell is usually covered with a thin EVA then we are not exactly replicating the cast condition but the shape of the orthotic is replicating the forces used. Orthotics work by applying orthotic reaction forces. I am replicating what an orthotic does ie pushing on a foot when I cast. The cast is not modified. It's easy, comfortable and reliable. My patients are happy. I'm happy.

    FWB, NWB, prefab, Mass...they all work so does a rolled up sock wrapped in tape..... seen that one a few times....

    Go ahead sharks feeding time has begun!!!
  26. Re: Research Parameters

    For those of you who don't why Sheldon is so excited about the FAS casting system..........http://footalignmentclinic.com.au/index.html

    All the testimonials remind me a little of Ed Glaser's and Brian Rothbart's websites.....maybe the "sharks" have found a new food source.....
  27. Re: Research Parameters

    Ye gods that was hard! Thanks for the link Kevin. Could have saved a lot have bush beating if we'd had that from the get go!

    Looks like an interesting system! I'm gonna go have a proper read of the website, see what i think. Then maybe we can finally get down to brass tacks.

  28. N.Smith

    N.Smith Active Member

    Re: Research Parameters

    It's late (only 10-30pm but I've got 2 young kids!) I'm tired but I'll respond tomorrow
    and hopfully answer some questions.


  29. Re: Research Parameters

    I just took a 30 second glance at the website. From the website:
    "An Orthotic works by forcing your foot into its most anatomically aligned position, which also has an affect on your upper body, allowing it to function in an optimum way."

    :bang: No they don't:hammer:. Please provide data to support this claim. You may want to ask C. Payne about this ;););); Optimum function? And you measure this how?

    "To make an Orthotic, plaster bandage is wrapped around your foot while you're sitting or lying down on your back or stomach. Your foot is then held in its neutral position so it lines up with the rest of your leg. The cast is then balanced, poured and modified by adding plaster to the positive cast which is done to try and replicate what your foot would look like in a Corrected Weight Bearing Position, which is a calculated guess at best."

    Naive. I use plaster bandage, foam boxes and I've even tinkered with scanning. I sometimes cast in neutral, sometimes I don't. Which ever way I capture a negative, I rarely carry out my positive prep with the design of trying to "replicate what your foot would look like in a Corrected Weight Bearing Position". Utter b@!!@cks. See my final point here. And the corrected position obtained using this tool is not "a calculated guess at best" because..........?

    "The Foot Alignment System works because of the patented Rearfoot, Forefoot and Arch Alignment Curves, which force the three segments of your foot into their corrected position. No two feet are the same, so the shape and force needed on each foot is different."

    So if it wasn't patented, would it still work? :D A quick glance at this contraption reminds me of something seen at an Rx summer school in about 1998 which went down like a lead balloon. I'm guessing that you can alter angles between forefoot and rearfoot segments etc. Sheldon, can you tell me the difference in the moment exerted about the STJ axis by two orthoses when a given foot is casted using the system with the rearfoot 2 degrees inverted and 4 degrees inverted respectively? Moreover, how is the "corrected position" determined?

    "Because the feet are corrected and aligned in a weight bearing position the forces and the shape of the orthotic are extremely accurate so the orthotic is not only corrective, but very comfortable."

    Yeah, because feet are fixed on top of the orthoses and cannot move once placed upon them. Again, very naive. Further, how does the casting device determine forces? How do these forces measured in static stance relate to the forces in a) walking b) running c) jumping etc.?

    All yours Robeer...... I await "correction".

    P.S. Something for the weekend for all. if the repeatability of this machine means you can set the platforms to the same angle repeatedly- great. But does this mean the joints of the foot are in the same position and that the 3d geometry of the foots outer surface is the same?.

    O.P.S. just thought of a brilliant way of comparing casts! More on that one later>
    Last edited: Jan 30, 2009
  30. Steve The Footman

    Steve The Footman Active Member

    Re: Research Parameters

    There seems to be a schism going on in podiatry between those who believe in the significance of their measurements and those who no longer cling to them as a "valid" measure.

    Simon I would say that for most podiatrists the comment...
    "To make an Orthotic, plaster bandage is wrapped around your foot while you're sitting or lying down on your back or stomach. Your foot is then held in its neutral position so it lines up with the rest of your leg. The cast is then balanced, poured and modified by adding plaster to the positive cast which is done to try and replicate what your foot would look like in a Corrected Weight Bearing Position" ... is actually what is done. It also reflects the thought processes of many podiatrists.

    If someone needed an orthotic to stand in all day then this may actually be a reasonable method and rationale of producing a workable orthotic.

    However if you are more interested in dealing with someone's active injury and the forces that have led to the injury then these methods/measurements become insignificant.

    Is biomechanics a static measure? Can static measurements be relevant or valid for a dynamic system? What does the reliability or repeatability of a measurement or method matter if it has no relevance to a patients problems?

    While the tissue stress model may be in the ascendancy I believe the static measurement model currently has many more proponents.
  31. Re: Research Parameters

    Perpetuating myths is not healthy.

    Name me one person who put's their shoes on in a morning and stands still all day. Irrelevant conjecture.

    Then I believe they should go back to school and try reading more and engaging in some common sense. As I said, perpetuating myths is not healthy; a lack of critical thinking is even more pathologic. And your assessment of the current beliefs of the international podiatric community and what "most podiatrists" do is based on? Jack.
  32. David Smith

    David Smith Well-Known Member

    Re: Research Parameters


    Ok! now we have found out a bit more about the system and FAC I can see the point of your questions. One has to ask tho why all the secret squirrel vagaries and vagueness? Wouldn't it have made more sense to state your interests at the beginning.

    Also what is you interest in FAS I don't see your name mentioned on the web site at all. I am assuming from your post that you're are something to do with FAS and Vertical Orthotics

    Anyway in the light of new knowledge lets have a look at your earlier replies.

    Are you asking, telling, or just making a statement of fact. From the sound of it you have made your mind up and really only want to confirm you theory rather than research it.

    Speaking of research your web site appears to say that this has already been done??

    "Neil, Gavin and Heidi have collaborated to create a clinic dedicated to providing a scientific and biomechanical solution to foot, lower limb and spinal pain."

    "He has tested the product through highly reputable third party research and used the outside expertise required to refine the product"

    What is it that you need from Pod Areana? You seem to have it all sorted??

    Quote from FAC web site
    "Research conducted at Latrobe University in Melbourne with 23 Podiatry students issued with The Foot Alignment System orthotics and traditional Non-Weight Bearing orthotics showed that 22 students preferred The Foot Alignment System orthotics with one having no preference to either."

    8 out of ten cats prefer Whiskas brand cat food (www.whiskas.co.uk) but that does not infer anything about its nutritional value.

    Can you give us a reference for this paper or perhaps attach the paper for us to read.

    Again why are you asking about research parameters when you don't want to do any and you appear to have all the publicity research you need. EH??

    What does this mean? Sounds good? so does Football a pint of Larger and a Steak pie.

    Is this the science bit?

    Sheldon, I don't really understand what your saying here but if your happy then everything is tickety boo. I can see that you could manipulate the weight bearing foot using your machine but then couldn't I do the same by getting my patient to stand in a foam box in a STN position.

    Can you explain in a more conventional manner what you mean and how you think orthoses work and how the FAC system knows anything about the forces applied or required. Does the reaction force of an orthosis rely solely on how hard you press the foot into a required shape or are these two thing entirely unrelated.
    What if you pressed really hard but your orthotic was made of ice cream wafers, could it apply the orthotic reaction force that the FAS system somehow calculates it to need.

    Your argument is full of sound bites and fancy scientificesque (good word eh?) terminology but has no substance. The FAS looks interesting but so far your argument looks a little weak.

    Perhaps Neil will shed some clarity and light on the whole subject when he gets back to Pod Arena.

    Cheers Dave
  33. Steve The Footman

    Steve The Footman Active Member

    Re: Research Parameters

    I did not say that it was right but was implying in fact the opposite.

    There is no doubt in my mind that the perspectives that are strongest on Podiatry Arena are not representative of the bulk of podiatrists worldwide. If you need proof then it would be easily found in the orthotic prescriptions of labs worldwide. Most podiatrists are still doing exactly what the FAS website suggests. This comment in no way makes the FAS system valid.

    While the Root system of making orthotics has lost favour on the cutting edge, it is still a simple logical system that many practicing podiatrists find comfort with. The fact that it has been largely disproved and has too many gaps to be clinically relevant does not change that. To deny the truth of this is disingenuous.

    Being out of touch with reality is not healthy either!
  34. Re: Research Parameters

    "And if 8 out of 10 cats all prefer whiskas, do the other two prefer Leslie Judd?": 99% Of Gargoyles Look Like Bob Todd- Half Man Half Biscuit, from the stunning and probably contemporary album- "Back in the DHSS"

    This, I've no doubt dates me and the whiskas advert dubbed by Leslie Judd- have you seen her lately? But who gives a ****, it's Friday night. Google, Youtube, enjoy.

    Jesus Christ, come on down!

    If you've ever wondered how you get triangles from a cow
    You need butter milk and cheese and an equilateral chainsaw...
    In debt I owe someone a fiver
    Maybe I should try my hand at drag
    James Dean was just a careless driver
    And Marilyn Monroe was just a slag

    99% of gargoyles look like Bob Todd

    Mary had a little lamb, the doctors were astounded
    Everywhere she went gynaecologists surrounded
    They've been cooking on Blue Peter now they're sampling the dishes
    'I don't normally like tomatoes, John, but this is delicious!'

    The son of Jimmy Clitheroe is shouting out,
    'Where's my Fiorrouci?'

    The Krona rumours spread, but they didn't tell the bread
    Did you honestly think that they would?
    And if eight out of ten cats all prefer Whiskas
    Do the other two prefer Lesley Judd?

    Last edited: Jan 30, 2009
  35. Steve The Footman

    Steve The Footman Active Member

    Re: Research Parameters

    My point exactly. Can't you read between the lines?

    What percentage of Podiatrists undertake continuing education? In Australia there is a Accredited Podiatrist scheme. It requires a pathetically small amount of continuing education in order to be accredited every two years. I suspect that significantly less than 50% of podiatrists are accredited. The percentage of those that graduated more than 15 years ago would be even less. I will try to find out the actual figures.

    Just because you keep up to date and all the podiatrists that you know do, does not make you representative.

    Furthermore having your head in the sand about the current beliefs does not help to change things for the better.
  36. Re: Research Parameters

    Clearly, I missed your ironic intimation that lay too subtle "between the lines" for me.

    Yeah, read it again and missed it again.

    Ironically, your sweeping statements here may be too decisive and clear-cut. What percentage of podiatrists live and work in Australia? Your parochial view-point does not make you representative of the global community either. What experience do you have of the casting techniques employed outside of your back-yard? What is your knowledge of global CPD requirements? BTW, in the UK in order to maintain HPC registration it is a requirement that CPD is undertaken, without registration one cannot use the title podiatrist. You may naively believe then that 100% of UK podiatrists undertake CPD; personally I don't. Regardless, go find the "actual figures" for all podiatrists, not just those on your door-step before making statements like:

    Prove it! Show me the data. I look forward to reading the results of your research- don't look upon this as an arduous task, look upon it as CPD.

    Luckily for me and my patients I do my utmost to keep on top of current "beliefs" and don't attempt to hang on to an invalid system of orthoses prescription because it's "simple", "logical" and something that I "find comfort in". While that may not (in your eye's) make me representative, I believe (and so does the HPC) it makes me a better practitioner. Since 1991 I've been working with podiatrists around the world in providing education about "current beliefs" in an attempt to "change things for the better"- what have you been doing in this time? I may, or may not have made a difference with these efforts. I have certainly ****** off a lot of people who found "comfort" in a system that seemed "logical", but in reality was "invalid". I will continue in that shared goal, regardless of your perceived popular endorsement of an out-moded status quo.

    Steve, I wish you well with your future, and "reading between the lines", I'm sure that you feel "comfort" in the techniques that you employ.

    Is there anybody in there?
    Just nod if you can hear me.
    Is there anyone home?

    Come on, now.
    I hear youre feeling down.
    Well I can ease your pain,
    Get you on your feet again.

    I need some information first.
    Just the basic facts:
    Can you show me where it hurts?

    There is no pain, you are receding.
    A distant ships smoke on the horizon.
    You are only coming through in waves.
    Your lips move but I cant hear what youre sayin.
    When I was a child I had a fever.
    My hands felt just like two balloons.
    Now I got that feeling once again.
    I cant explain, you would not understand.
    This is not how I am.
    I have become comfortably numb.

    Just a little pinprick. [ping]
    Therell be no more --aaaaaahhhhh!
    But you may feel a little sick.

    Can you stand up?
    I do believe its working. good.
    Thatll keep you going for the show.
    Come on its time to go.

    There is no pain, you are receding.
    A distant ships smoke on the horizon.
    You are only coming through in waves.
    Your lips move but I cant hear what youre sayin.
    When I was a child I caught a fleeting glimpse,
    Out of the corner of my eye.
    I turned to look but it was gone.
    I cannot put my finger on it now.
    The child is grown, the dream is gone.
    I have become comfortably numb.

    "Comfortably" numb= Pink Floyd
    Last edited: Jan 31, 2009
  37. Steve The Footman

    Steve The Footman Active Member

    Re: Research Parameters

    Clearly you are more interested in ****-stirring here than meaningful debate.

    I personally think a forum is a perfect place for generalisations as it is by default people giving their opinion unless referenced otherwise.

    Perhaps you recognise these generalisations:

    "What the world needs now is more people selling foot orthoses, who don't have the faintest idea of what they are doing."

    "want my bored with your smart ass answers (which in fact make you look foolish because what they really show is that you haven't read the post properly) reply?"

    "if you look at the origins of qualitative research it was developed as a backlash to the perceived masculinity of science."

    "Most labs will blend the medial addition to end roughly in the area of the navicular."

    There is a name for someone who holds other people up to a higher standard than themselves:
    Considering your difficulty in comprehending my posts, click between the lines to find out.

    Without any hint of sarcasm I think you are an excellent role model as a podiatric clinician and educator. I aspire to someday attain a fraction of what you have learned and achieved. I agree with most of your posts and admire your humour and no bull**** attitude. The profession is enhanced by people who are willing to "**** off a lot of people" for the good of us all - even those who resist it. I personally have gained a lot from your insights and look forward to the continued wisdom that you are willing to share.

    However that does not make me fall for this.

    Saying that I will review my posts in the future to reduce unfounded generalisations and speculations.

    THIS IS THE COMMENT that has got your gander up:
    Simon I would say that for most podiatrists the comment...
    "To make an Orthotic, plaster bandage is wrapped around your foot while you're sitting or lying down on your back or stomach. Your foot is then held in its neutral position so it lines up with the rest of your leg. The cast is then balanced, poured and modified by adding plaster to the positive cast which is done to try and replicate what your foot would look like in a Corrected Weight Bearing Position" ... is actually what is done. It also reflects the thought processes of many podiatrists.

    This generalisation was prefaced as an opinion. Perhaps it was a mistake to use your name but I was responding to your criticisms in someone's previous post as being naive.

    Whether you want to believe it or not my comments were not an endorsement of the status quo or the FAS method. When I was at Uni there was significant pressure to prescribe at least one Root device to a patient. I refused to do so, despite the fallout, because I felt there was enough evidence that it was no longer the best treatment option. I also do my utmost to keep on top of current practices. I embrace the scientific method where no idea or concept is sacrosanct. Even the most cherished beliefs and methods have a chance to be disproved someday.

    We will all be better practitioners if we continually challenge the current system rather than take comfort in the status quo. (another good generalistion for you)

    Unruly boys
    Who will not grow up
    Must be taken in hand
    Unruly girls
    Who will not settle down
    They must be taken in hand

    A crack on the head
    Is what you get for not asking
    And a crack on the head
    Is what you get for asking

    Unruly boys
    Who will not grow up
    Must be taken in hand
    Unruly girls
    Who will not settle down
    They must be taken in hand

    A crack on the head
    Is what you get for not asking
    And a crack on the head
    Is what you get for asking

    No ... a crack on the head
    Is what you get for not asking
    And a crack on the head
    Is what you get for asking

    A crack on the head
    Is just what you get
    WHY ? Because of who you are !
    And a crack on the head
    Is just what you get
    WHY ? Because of what you are !
    A crack on the head
    Because of :
    Those things you said
    Things you said
    The things you did

    Unruly boys
    Who will not grow
    Must be taken in hand
    Unruly girls
    Who will not grow
    They must be taken in hand
    Ah ... oh, no ... oh, no
    The Smiths "Barbarism Begins at Home"
  38. N.Smith

    N.Smith Active Member

    Re: Research Parameters

    Firstly. I didn't ask Sheldon to post about the FAS, and he has no part of the Foot Alignment Clinic. He dose have a FAS machine, but works from NZ and is obviously very passionate about it. He knows I was given a Govt. Grant and was going to use some of that money to do research, so was puttinig the feelers out as to the best way to go about it.

    I never came up with the idea to make the Foot Alignment System to take over the world or to get under anyones skin and can't see what all the fuss is about.
    There are only 21 machines being used in private practice with the Foot Alignment Clinic having 4.

    I've been in the industry for 27 yrs now, and in that time made 80+ thousand jobs, all by hand, (my 99 yr old grandmother has nicer looking hands than me!) with a lot of thought going into each one. When I first started we didn't even balance or modify the casts, they were just poured, cleaned and jobs made.
    Now, there are so many techniques with casting and orthotic manufacture ie: Non-WB, Semi-WB Supine, Prone, 4th and 5th load, Suspention, Invert, Evert, Skive, Flanges.... it's hard for the average practitioner to know what's best. IMO and from what I've seen , most practitioners find a formula and stick to it by prescribing the same thing for each patient, but hey if it works, why not!

    The hardest part about orthotics (for me) has always been teaching someone to balance and modify the positive cast. No matter how much you explain yourself or how long they do it for, no one dose it as good as they were taught. Close, but not the same! This was always frustrating and the main reason for the invention. If the patient wasn't happy with the orthotic, 9 out of 10 times it's the labs fault ie: MLA too high, not long enough, Wide enough, uncomfortable etc... etc... It all comes back to the cast.

    With the FAS, the onus is on the practitioner to get it right. Why leave it up to the lab technicians skill or not. The shape and forces through the foot you produce are in the cast and this is what you get back in the orthotic. Position the foot where ever you want! Under-correct, over-correct the heel, MLA or F/F, deflect areas on an elongated WB foot shape, Raise and tilt the heel to mimic the shoe shank and height and get the correct angle and base of gait before casting. The choice of where the foot ends up and how it feels in the orthotic is up to the clinician.

    Someone said you can do the same thing with foam boxes or semi-WB casts by positioning the foot into where you want it to sit and that's where the foot will be in the orthotic. How? there are no vertical, translational or rotational forces acting on the foot to keep it there. The same goes with positioning the foot Non-WB in a cast, modifying it and the orthotic will hold the foot where you want it.

    You're right when you say that having a study done on repeatability is a start but doesn't mean much because you could be repeating the wrong thing! The study done on comfort and control had all the Non-WB casts taken by C.Payne and sent to a leading lab in Melbourne with a set manufacturing protocal. All FAS casts were taken by CP and sent to my lab for manufacture. All but one person (having no prefference to either) preffered the comfort and fit, with negligent difference in
    control. Obviously not enough, but it was a start. Both studies were also done on one of the first versions of the machine and I feel the improvements on the newest version give a far better cast so it would be great to get some advice on research from you guys, being the leaders in the industry.


    Neil Smith
  39. Re: Research Parameters

    http://en.wikipedia.org/wiki/Sarcasm. And I stand by this sarcastic comment when I read things like: "An Orthotic works by forcing your foot into its most anatomically aligned position, which also has an affect on your upper body, allowing it to function in an optimum way." Yep, there's another one. Steve, does this sound like these individuals have a firm grasp of how orthoses work to you? Five minutes googling and I could provide hundreds of statements like this from companies selling foot orthoses. When I'm not busy and I've got the time I will.

    Read the posts in context, just the lines, no need to look for imaginary meaning between them in this: http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=23630

    Westmarland, N.: The Quantitative/Qualitative Debate and Feminist Research: A Subjective View of Objectivity. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research
    Volume 2, No. 1, Art. 13 – February 2001

    "Research methods are "technique(s) for ... gathering data" (HARDING 1986) and are generally dichotomised into being either quantitative or qualitative. It has been argued that methodology has been gendered (OAKLEY 1997; 1998), with quantitative methods traditionally being associated with words such as positivism, scientific, objectivity, statistics and masculinity. In contrast, qualitative methods have generally been associated with interpretivism, non-scientific, subjectivity and femininity. These associations have led some feminist researchers to criticise (REINHARZ 1979; GRAHAM 1983; PUGH 1990) or even reject (GRAHAM & RAWLINGS 1980) the quantitative approach, arguing that it is in direct conflict with the aims of feminist research (GRAHAM 1983; MIES 1983). It has been argued that qualitative methods are more appropriate for feminist research by allowing subjective knowledge (DEPNER 1981; DUELLI KLEIN 1983), and a more equal relationship between the researcher and the researched (OAKLEY 1974; JAYARATNE 1983; STANLEY & WISE 1990)."
    ANTHONY RJ: The fabrication protocol for the manufacture of a functional foot orthosis. J Br Pod Med 47: 91, 1992 "a prominent and distinctly defined shaft of plaster added along the inferior aspect of the 1st metatarsal, back to the sustentaculum tali". I did say "roughly".

    I'm just an average guy, full of the faults and traits that make us human, but I do like to be able to put my money wear my mouth is. Now back to your research into global trends in casting and orthoses fabrication protocols, Steve....
    Last edited: Jan 31, 2009
  40. Re: Research Parameters

    Steve and Simon:

    Dueling song lyrics......what a great idea as a way to have an academic discussion as to the benefits of different casting techniques!!!!:rolleyes::boxing::drinks

Share This Page