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Determination of normal values for navicular drop during walking: a new model correcting for foot length and gender

Rasmus G Nielsen, Michael S Rathleff, Ole H Simonsen, Henning Langberg

Journal of Foot and Ankle Research 2009, 2:12 (7 May 2009)

Background
The navicular drop test is a measure to evaluate the function of the medial longitudinal arch, which is important for examination of patients with overuse injuries. Conflicting results have been found with regard to differences in navicular drop between healthy and injured participants. Normal values have not yet been established as foot length, age, gender, and Body Mass Index (BMI) may influence the navicular drop. The purpose of the study was to investigate the influence of foot length, age, gender, and BMI on the navicular drop during walking.

Methods
Navicular drop was measured with a novel technique (Video Sequence Analysis, VSA) using 2D video. Flat reflective markers were placed on the medial side of the calcaneus, the navicular tuberosity, and the head of the first metatarsal bone. The navicular drop was calculated as the perpendicular distance between the marker on the navicular tuberosity and the line between the markers on calcaneus and first metatarsal head. The distance between the floor and the line in standing position between the markers on calcaneus and first metatarsal were added afterwards.

Results
280 randomly selected participants without any foot problems were analysed during treadmill walking (144 men, 136 women). Foot length had a significant influence on the navicular drop in both men (p<0.001) and women (p=0.015), whereas no significant effect was found of age (p=0.27) or BMI (p=0.88). Per 10mm increase in foot length, the navicular drop increased by 0.40mm for males and 0.31mm for females. Linear models were created to calculate the navicular drop relative to foot length.

Conclusions
The study demonstrated that the dynamic navicular drop is influenced by foot length and gender. Lack of adjustment for these factors may explain, at least to some extent, the disagreement between previous studies on navicular drop. Future studies should account for differences in these parameters.

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Open Access - all papers full text for free

Good! Shame they did not tell these people about correcting for foot length!

As I said in this thread:

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Craig Payne
Department of Podiatry
La Trobe University
Melbourne, Australia
http://www.latrobe.edu.au/podiatry
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God put me on this earth to accomplish a certain number of things - right now I am so far behind, I will never die.
The views expressed above are those of the author and not that of La Trobe University
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Related threads:
Help needed interpreting Navicular drop & drift measurements?

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I assume your 280 subjects were randomly selcected in essence encompassing a bell curve of foot types.

Two Questions:
1. Theoretically, if you took your same 280 subjects and profiled them first into foot types, do you think that your important technique of measuring navicular sag would provide more information and expose the need for further investigation in foot type-specific areas.

i.e.the rigid/rigid would reflect small sag,
the rigid/ flexible type would have a greater sag, mostly forefoot and
the flexible /flexible would have the greatest sag coming from both rearfoot and forefoot.one level of sag

This means that, at that point, you could then examine the bell curve of each foot type instead of examining the bell curve of all feet and get more additional information from the study.

2. What treatment applications did your study evoke?

Dr Sha

just realized that you were not an authot, sorry
dennis

Interesting questions Dennis. However since FFT is unknown outside of your writings I suspect few would be interested in doing this research on FFT for you!

If you want question 1 answered you need to do the research yourself, find someone else who share's your passion to do it or pay an independent researcher to do it for you!

Be careful if you do though. Question 1 turned from a question to a statement. If you were to design this study you would need to be careful to avoid introducing bias to the methodology and write up . Otherwise the work would be wasted.

IF such a study were carried out and IF it found as you predict (which would, BTW, seem reasonable) it would indicate that FFT was predictive of Nav drop. However this would not make it unique nor especially diagnostically useful. The supranavicular line (feiss line) measurement is also predictive of nav drop so we already have an assessment tool for that.

A far more interesting question, for me, is, is nav drop predictive of pathology. Or indeed is pathology predictive of Nav drop. Either makes sense. Don't forget, correlation is not causation.

From your point of view I would be trying to design a study to show whether particular foot types are predictive of particular pathology. If, for eg, you were able to show that the rigid / flexible type was predictive of HAV, or that flexible / flexible was predictive of PF you might have the base (only the base mind) of the evidence you need to convince people.

Of course the next thing to prove would be that foot centering insoles have a measurably difference to other types of insoles, preferably with a randomized and blinded outcome study. THAT would be something to show us.

If you need a decent study design get the full text of this piece

http://archinte.ama-assn.org/cgi/con...ct/166/12/1305

Landorf went to considerable effort to attempt to remove bias and error from the methodology. Look to the way he blinded the participants. That would be a minimum pre requisite for your study.

Go for it! Three way study for PF. Foot centerings, pre fab soft foam and Root standard. Single blinded randomized control trial. If your system is as good as you say it is then there will be significantly better outcomes with your devices. If the study proves no such superiority you will be no worse of than you are now (and no worse off than the rest of us).

A good outcome in such a study is what you need if you wish to claim superiority.

Regards
Robert

PS. And no cheating by proving your insoles are better than a piece of flat foam.
Thats been done but it does not impress.

PPS. I suspect the "pain relief is not the outcome we should seek" argument is hurrying with ill advised enthusiasm toward this thread. If so I Invite it to design a study to show that one foot function is better than another without referring to improvement / prevention of pathology. The bravest of researchers would baulk at that one!

Of course you can't prove a negative but as the tireless newsbot reports

Here is an interesting question. If shock during running IS a risk factor and IF pronation has a role as a shock ABSORBER what makes more sense. More pronation = more knee pain or more pronation = less knee pain.

Would NO pronation be good? Does the future of biomechanics lie in ever more aggressive orthotics to supinate the foot or in the timing of the force they exert?

And is the amount of pronation as important as the quality and speed of the pronation.

Forward the Supination Resistance Test?

Kinematics or kinetics?

Questions questions, always questions. It used to be so simple.



Regards
Robert

DrSha

You wrote

What do you mean by this questioning statement ?

Isn't it quite likely that such a large sample population would return a normal distribution curve? Skew curves usually come from small samples or biased samples can give a skew curve. E.G. if you did a study to find the normal height of Americans and only drew your sample from one college basket ball team. The sample would be small skewed to the tall side. No matter how large you made the sample, e.g. it could be 2200 from a team of 15 players, it would most likely return a curve showing the mean as very tall. However, then though the curve would most probably be normal.

Was it rhetorical or does it require and answer?
Can you clarify please?

Nielson et al wrote
The title of this study was

Determination of normal values for navicular drop during walking: a new model correcting for foot length and gender

Wouldn't this would suggest that random was only random after it had been biased by some perception of normal selection criteria.

This will give an idea about the normal (1) distribution of navicular drop in a preselected population defined as normal (2).

Where, Normal (1) is some SD cluster around the mean value for a gaussian curve or data histogram.

And, Normal (2) is some arbitrary measure of normal, which one might assume in this study correlates to non pathological or some predetermines range of motion of some joints of interest. Both leave a lot to desire in terms of the definition of normal and how one gauges non pathological.

Shouldn't normal be based on a large randomly selected sample population from a population containing all foot variations (e.g. drawn from a database of everyone in Kentucky). Presumably then, the normal (2) might be expected to correlate with the normal (1) since it might be reasonable to assume that the general meaning of normal (2) is the condition of most people in a population' then this will be reflected by normal (1) would it not?

Cheers Dave

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Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.

In addtiion to skew, you also need to look at kurtosis:
http://en.wikipedia.org/wiki/Kurtosis
http://www.itl.nist.gov/div898/handb...on3/eda35b.htm

There are a number of tests that check for normal distribution, these ones are fairly common:

Kolmogorov–Smirnov test (named after the vodka!)
Lilliefors test
Shapiro–Wilks test
Normal probability plot

Nice wikipedia entry on all of this here:
http://en.wikipedia.org/wiki/Normal_distribution


You are joking, right Dave? You're asking Dennis, the man who took three days to come back to me with a cut and paste of my own post to him (Dennis , thanks for proving me right again ) in the need for orthotics thread.

Anyway, enough about lack of original thought, retrograde ideas in podiatric biomechanics and foot typing systems ripped off from Paul Scherer. My current problem is that I can't get the full paper because for some reason my mac won't load pdf's from certain sites, this being one of them.

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The timing, as well as the point of application, the direction and magnitude of the forces they exert will all be controllable in the future of foot orthoses.

What do you mean by the "quality of pronation"?

Supination resistance test tells us the amount of force required to initiate re-supination in static stance with a force exerted from below and superiorly directed to the navicular- if we are doing it as designed and described- right? How does this relate to the force required to resupinate the foot during gait using an orthosis? Moreover, how does this relate to the force exerted by an orthosis during gait? What if we could measure supination stiffness? (BTW we can), how would this help, if at all?. What if we could measure supination stiffness during gait? (I'm thinking about how to measure it... are you? I'm sure somebody smart at math can work all of this out Ma =? Surface stiffness=? deformation =?; ???+????), what if we could measure the stiffness of the orthoses ? We can. What if we could work out the direction of an orthoses reaction force vector for a given point on the orthosis surface (Can we?). How do we get from a to b- Robeer, Dave, Kevin, Eric, Craig et al.? We all "know" the science, but we aren't combining our talents to come up with the solutions yet- too much utopia for a Monday night, but it still beats trying to classify the feet we encounter into a dozen, two dozen or three hundred dozen "types", because what's on top of those "types" and what those "types" are doing and in which environments, is always going to confound any pseudo-classification systems- right? Or, does that just sum up the whole problem. Some times I just see it for what it is... to much to solve.

Both.

No, people just lied to you and you made the choice to believe the lie (which was always there: believe).

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OK, lets take the navicular during full foot contact as an example: GRF = Y and navicular height = X, If we work out y/x for a given foot at given intervals of time this the dynamic stiffness of the navicular- right?

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Supination resistance has many variables that may affect its determination and consistency of measurement. First of all, supination resistance will increase in magnitude as the individual leans forward and will decrease in magnitude as the individual leans backward while in bipedal stance. Also, supination of the subtalar joint will lag behind raising of the navicular with a supination resistance device so one must decide if one is going to measure the displacement of the navicular or angular change of the calcaneus for the parameters of a stiffness measurement. In addition, tonic muscle activity of peroneals and posterior tibial muscle will also affect any stiffness measurements and these muscles are active in many individuals while they are standing in relaxed bipedal stance, even though few podiatrists realize the fact that the peroneals and posterior tibial muscles are often tonically active during standing.

Should give you something to chew on, Dr. Spooner.

BTW, I will classify my new diagnosis of "Gravity Syndrome" into a 16 different subtypes and have already applied for a patent for my new antigravity orthoses and for each of the different subtypes of "Gravity Syndrome". In addition, I will be applying to trademark the term "Gravity Optimized Orthoses" so that I can try to make as much money over something I thought of just a few hours ago. Maybe I will also send my upcoming paper on "Gravity Syndrome" to Gait and Posture so it can (like other podiatrists that think they understand biomechanics better than others) be rejected by the reviewers to then get it published in another journal that is so anxious for anyone to submit a paper on biomechanics that it will print just about anything.

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Sincerely,

Kevin

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e-mail: kevinakirby@comcast.net

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Simon


My expectations are low and so easily fulfilled but not so readily frustrated.


Ah yes! I always forget about Kurtosis till I see it.

Not quite, unless you mean the summation of (x z y) at a certain point on the foot relative to the navicular i.e. Centre of Force * distance which will reveal the moments about the navicular in terms of the force vector. Your equation would give a coefficient of deflection (x) in terms of GRF (Y) but I'm not sure if this would be useful, would it? Maybe it would be some indication if one only had a pressure mat system, would this be useful??

Cheers Dave

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Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.

Having just read the full paper the methodology leaves a lot to be desired in my opinion.

Using 2D video with high speed camera recording at 87Hz and three adhesive skin markers on heel, 1st mpj and navicular they measured the navicular drop (ND) from heel contact to the point where the navicular was lowest relative to the ground. This was repeated 20 times.

Description of methods to collect data is very scant one assumes that they used a triangulation of the three markers and the change in geometry to calculate the arch height from navicular.

It is not stated how they would account for error due to change in angular foot placement perspective due to the toe in or toe out characteristics of the subjects. Especially since this angle often changes thru the stance phase.

Taking y as vertical x as anterior posterior and Z as medial lateral axes then:

Neither do they say how parallax was accounted for or how foot placement could always be congruent to the camera view in the Z axis.

I.E. for both these points the view of the markers by the camera will effectively reduce the distance between heel and 1st MPJ marker if they are not at 90dgs to the camera view. Therefore there will be considerable error in the trigonometrical calculations to find the ND.

There is in fact no description of data manipulation or processing or mathematical formulae used.

The Navicular Marker was placed on skin, the navicular joint moves quite freely under the skin and in my opinion this marker technique would be quite unsuitable for the precision required for this type of data collection. I would predict around a 50% error between skin marker and actual distance moved by the navicular.

If they took the navicular at its lowest point relative to the ground as the limit of ND then how did they correlate this with the triangulation method. In the paper it merely say " the distance between the heel and 1st MPJ markers and the ground was added afterwards"?????

How did they measure that? wouldn't that distance change as the load applied and the discreet plantar pressure changed and the soft tissue compressed. The load goes from zero at heel strike to around 120% bodyweight at peak load.

Seeing as they are using a range of 13mm and a precision of 0.3mm then I am sure that these limitations would significantly effect the results in terms of absolute values. In terms of the conclusion, that foot length significantly affects the range of ND, these errors are probably consistent, according to ICC test they are, and so seems reasonable in terms of increased lever arm = increased bending moments and so greater deviation.

BMI seems to be a red herring since it is only a normalised coefficient of height and bodyweight. Therefore tall or short the BMI could be approximately the same. However the foot length and moment arm would most likely be considerably more for the tall person. The tall person will also be heavier so this again will increase bending moments about the navicular.

Simple reasoning would predict that the larger foot would have a larger RoM in terms of ND. The graph below shows how the ratio of angular deflection to change in apex height (sine) is greater as the metatarsal length becomes longer I.E. 80mm, 100mm 120mm.






Now if one considers that the stiffness of the navicular joint comes from the resistance applied by the plantar aponeurosis and ligaments then even if they have the same tissue stiffness through out the range of subjects feet the stress / strain ratio (Young's modulus or E) will predict that for the same cross sectional load the longer tissues will have greater extension.

The moments about the navicular of the long foot will be greater and so the total load will be greater on the plantar tissues but they will likely be thicker and so cross sectional load may be similar through out the foot range.

Hey! my brain is hurting and I want to go home now so I'll carry on with this later.

I'm not sure if this paper had anything useful to say and what it does say must be approached with caution.

Cheers Dave

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Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.

Thank you Robert for continuing to direct me towards your way of working or enabling me to attach to it.
Dennis

Dave, I originally posed similar questions last night, but edited them out of my postings because I hadn't read the full paper. I agree that this appears to be a methodological flaw, at least I think it is- I changed my mind about three times last night How are they using the distance data between heel and 1st MPJ marker? Are they measuring this distance or just using this as a baseline to measure navicular height from?

Somebody e-mail the paper please:
skspooner@blueyonder.co.uk

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To pick up on a few points

Wow. We really are doing baby steps toward that!

I'm not exactly sure. I think I mean timing, velocity and amount of force involved in the movement. For EG. two feet which pronate at the same time, to the same degree and at the same velocity but move with different degrees of force and therefore require different amounts of supination moment to attenuate. Trouble is I don't have the language to express that clearly .



I'm going to disagree with you there. The people who taught me beleived what they were teaching so it was not really a lie. Also the "truth" of foot function is so complex it is probably beyond the capability of most (all?) of us to fully comprehend. Thats why we make models, to enable us to grasp some elements of the whole.

Consider the axial shadow in the SALRE model. WE KNOW it is only a shadow and not the true axis. We know that the axis is a 3 dimensional one not a two dimensional one. I think that the vector of force and the friction co-efficient of the orthotic (and the shoe) will have an effect partly dependant on the location of the axis in the sagital plane. However for most podiatrists at the coal face the 2d shadow model is a much more accessable, diagnostically useful and prescription relevant model to use day to day.

What is preferable, for the bulk of the profession to use a model which is flawed but useful, or for biomechanics to be taught in its full, glorious, horrible complexity and be grasped and used only by the few who can comprehend it?

How many GPs truly understand the biochemical mechanism for the drugs they issue? Does that make them poor GPs? Does it make it a lie when they say "paracetamol is a pain killer".

For me, the LIE, in biomechanics is when people mistake the model for the truth, or embrace the model so keenly they stop looking for the truth. That is where the rot sets in.

Regards
Robert
(or is it?...)

When I was into education and training Carl Rogers was king: http://www.panarchy.org/rogers/learning.html

The only time I think of the STJ axis in 2D is when I'm trying to explain to patients, in my prescription writing I always think in 4D. Is this an educational issue?

I was taught Root 101, but didn't attend the lectures as I was way to busy jamming with my band, chilling and maxing. Time revealed that this was a good thing as I didn't need to unlearn the Root dogma and when Kevin's early papers along with Daryl Phillips work on STJ axis jumped out at me, I got it early on. I learned through reading and the processes outlined by Rogers above. I'm no smarter than your average shamopodist, but I did dedicate the time to learning.

Yeah, that's when your lecturers just give out the same old same old because the summer holiday is just that, and not a time to be updating and improving the lectures with more recent knowledge.

Me, I was born cynical and slippy, I watched the X-files and know that the truth is out there.. But it isn't about to present itself to me on a plate. So you got to keep searching...

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Simon,

PDF of the full article

Ian

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Thanks Ian, but I need you to e-mail the pdf as an attachment not a link to the paper as for some reason this just crashes my browser.

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Done just now

Ian

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Originally Posted by Robertisaacs
For me, the LIE, in biomechanics is when people mistake the model for the truth, or embrace the model so keenly they stop looking for the truth. That is where the rot sets in.

Simon Says:
Yeah, that's when your lecturers just give out the same old same old because the summer holiday is just that, and not a time to be updating and improving the lectures with more recent knowledge.

The dictionary states:
Knowledge:
a1. the fact or condition of knowing something with familiarity gained through experience or association
(2): acquaintance with or understanding of a science, art, or technique
b (1): the fact or condition of being aware of something (2): the range of one's information or understanding <answered to the best of my knowledge>
c: the circumstance or condition of apprehending truth or fact through reasoning : cognition d: the fact or condition of having information or of being learned <a person of unusual knowledge>
Dennis States:
Your perversion that knowledge of biomechanics is based on a knowledge of engineering and on research that is questionable and biased is the root of your flaws.
There is no reason why utilizing architecture as a language to upgrade the foundational knowledge with modern (your definition, once again biased ) knowledge could not be a competitive model for clinical practice.
But competition does not live long on The Arena.

Dr Sha

Dennis:

There is no reason why the principles of architecture can't be used in modelling the foot. This is because architecture is based on the science of mathematics, physics and engineering. However, just because you use some of the terminology from architecture in your classification system of foot types, this does not also make your system of foot classification system meaningful or accurate.

The podiatrists on Podiatry Arena are not average podiatrists that will blindly start to believe everything that someone with a pretty slide show or a patent or a trademarked idea presents to them. I think you would do much better at selling your foot classification system to less sophisticated podiatrists, rather than to the ones who discuss biomechanics here on Podiatry Arena. No matter how hard you try, I'm afraid that we just aren't going to buy into it.

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Sincerely,

Kevin

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Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College

e-mail: kevinakirby@comcast.net

Private Practice:
107 Scripps Drive, Suite 200
Sacramento, CA 95825 USA
My location

Voice: (916) 925-8111 Fax: (916) 925-8136
**************************************************

I think thats a terribly cynical view of the "average" podiatrist.

I'm not sure its inaccurate though.

Perversion. How well you know us.

Is not biomechanics, by definition, the mechanics of biology? Are not mechanics and engineering inherently intertwined?

Kevin said:-
I think there is. Or rather I think there is a reason that architecture based models are inherently inferior to engineering based models and dangerous to use.

Architecture does not tend to move about much. Engineering does!

For me, one of the lies that Simon spoke of is that one can consider a static foot, either on the couch or in static WB, and use that as an analogue for function. How often on prescription forms or marketing does one see questions like "is the foot pronated?". This is one of the things which leads to sloppy thinking. Because of this I am always suspicious of ANY model which considers the foot as a static structure.

One of the "conversations which changed my world" in biomechanics was when Dave tried to explain inertia to me. Everything changes.

Kind regards
Robert

Kevin Stated the Kirby and Arena bias quite clearly when he posted:
The podiatrists on Podiatry Arena are not average podiatrists that will blindly start to believe everything that someone with a pretty slide show or a patent or a trademarked idea presents to them (what makes you think that the rest of us do?). I think you would do much better at selling your foot classification system to less sophisticated podiatrists, rather than to the ones who discuss biomechanics here on Podiatry Arena. No matter how hard you try, I'm afraid that we just aren't going to buy into it.

Kevindefines sophisticated podiatrists as “the ones that discuss biomechanics here on Podiatry Arena”.

Dennis States:
Every statement coming from The Arena must be prefaced by this perverted, evangelical, fundamentalist viewpoint!!!
but
I can these statements two ways. One that "I am sophisticated" as I discuss biomechanics here on The Arena or the other that by definition, all DPM’s not visiting The Arena are inferior to Dr. Kirby and The Arena members. It is the fundamentalist part of Dr. Kirby’s ideology that concerns me greatly not his valuable and brilliant additions to our science.
The dictionary defines sophisticated as:
1.sophisticated - having or appealing to those having worldly knowledge and refinement and savoir-faire; "sophisticated young socialites"; "a sophisticated audience"; "a sophisticated lifestyle"; "a sophisticated book"
2.sophisticated - ahead in development; complex or intricate; "advanced technology"; "a sophisticated electronic control system", advanced
3.sophisticated - intellectually appealing; "a sophisticated drama"; appealing to or using the intellect; "satire is an intellectual weapon”

I believe The Arena Sophisticates are light years ahead when it comes to engineering terminology applications and establishing and utilizing fundamental research protocols but they are far from sophisticated with their Subtalar Neutral Casting technique for plastic shells, their use of soft and forgiving materials in fabrication of “potentially” corrective orthotics and most important, in their clinical lack of an open mind and idealistic goals when it comes to offering care to the foot suffering public.
The Arena sophisticates have basically eliminated the placebo effect from practice. Statements like “there is absolutely no proof that an orthotic can do anything to prevent or correct a bunion” leave patients with no hope. My years of schooling, post graduate education and practice start me out with a better healing model than the average person, period and therfore I have placebo power. What a waste of yours (i.e. Simon played in a band and I assume honed his anger instead of going to class and getting a foundation in podiatry).
Your unsophisticated reverse morton’s extensions, your disregard of urban desires of patients to wear stylish shoes, your lack of flexibility and compassion, your lack of understanding what the foot suffering public is looking for beyond pain relief from the podiatry community is lost in your test tubes.

The saddest part is that your engineered and researched biomechanics focuses on gait, which is only a small part of our closed chain lives.
How does your orthotic fare when the forefoot is first contact as in backwards movement? How does it work when one foot contacts medially and the other laterally as in side to side movement? How much positive clinical impact does it have when the body is in static stance dividing weight evenly on the rear and fore pillars. How does your orthotic match up in the portion of the population who is ill, weak or old and cannot move through the phases of gait?
The "contact phase of gait" and "toe off" does not apply to a large portion (unproven and lacking in engineering terminology) of our daily lives.

In my opinion, the goals of biomechanics and the casting, prescribing and fabrication of sophisticated orthotics should be designed for closed chain life and not closed chain walking, as your unsophisticated debates and devices are.

I continue to cherry pick The Arena for knowledge and a better understanding of biomechanics and orthotics but I am pleased to remain unsophisticated in the self annointed eyes of Kirby, Spooner, Ian, Graham et al. Your anger and sarcasm fuels my passion to persevere and I thank you for that education.

“Sophistication might be described as the ability to cope gracefully with a situation involving the presence of a formidable menace to one's poise and prestige”.
James Thurber

Dr Sha/Mr Hyde, Arena Senior Member

Our problem is that our "older" forms of assessment eg measuring angular realtionships of rearfoot to leg or forefoot to rearfoot etc are not particularly predictive of dynamic function.

But as Robeer states we do need a model for understanding as the whole thing is otherwise to complex to compute in a clinical setting. Just because old tests dont give us the info we need doesnt mean a new test can't.

Thus we need simple, and yes probably static, tests that give us data to allow us to make assumptions about dynamic function and "risk factors" for injury. So when you visit your GP and they diagnose you with hypertension the will often do so with measurements based on you sat "comfortably" on their couch. Does this reflect your blood pressure a normal busy day running around at work and then dashing home to do your chores? No but sufficient data has been found to allow the clinician make some assumptions and start treatment.

Examples in Podiatry or workable predictors of dynamic function may be the STJ axis position and the supination resistance test. Are they 2D or 3D tests? Of course the "4D" is the crucial bit but are they tests that allow us to write a 4D prescription with "2D" data?

I used to think that in-shoe pressure was going to be "it" but having used one Im not so sure. There has to be a simpler way - I think belied by the fact that orthotic Rx's often tend to be reasonably similar from patient to patient.

Bevan Stated:
Thus we need simple, and yes probably static, tests that give us data to allow us to make assumptions about dynamic function and "risk factors" for injury. So when you visit your GP and they diagnose you with hypertension the will often do so with measurements based on you sat "comfortably" on their couch. Does this reflect your blood pressure a normal busy day running around at work and then dashing home to do your chores? No but sufficient data has been found to allow the clinician make some assumptions and start treatment.
Dennis States:
Brilliant!!
dennis

Gosh Mr Hyde, you're in fine voice today. And congrats on becoming a senior member btw.

Too much in your post to address point by point, and some not worthy of it. However I would pick up this point.

Several points spring to mind.

1. If we no something to be fallacious, is it ethical to continue to preach it to patients just to give them hope? Especially when one is charging them hansomly for the priviledge? Is this not the very definition of snake oil?

2. What makes you think you know what we do in clinical practice? What we discuss amongst ourselves may not be reflective of what we communicate with patients.

3. The placebo effect is all well and good. And undenyably powerful. But should our treatments lean on this? After all true medicine works whether you beleive it or not!

Once again you presume knowledge of how other podiatrists practice. Its irritating.

"FFT? Oh thats just a series of formula's which produces high arch and uncomfortable orthotics. The rest of us are using advanced materials and TRULY customised prescriptions! A foot centering orthotic isn't much better than a pre fab and can't hold a candle to a properly prescribed orthotic where the clinican can choose the material, casting postion and prescription WHICH IS RIGHT FOR THE PATIENT instead of just reading it off a chart! Unfortunatly Dennis is so evangelical about his cookie cutter system he can't open his mind to accept new ideas. Limiting the clinican to a single prescription, a single unforgiving and hard material and a single casting position reduces the podiatrist to being nothing more than a technician. By his own admission Dennis does not care about releiving pain but is only interested in putting the foot in the unnatural and uncomfortable position he thinks is best."

Annoying init. I would not dream of writing this, but this is pretty much what you are doing!

Regards
Robert
PS. I'm disappointed that in your diatribe (which adds little but pisses people off plenty) you neglected some interesting discussion points. For eg. How would you answer this

or this
Regards
Robert

Dennis - 6 more posts and you'll be a Podiatry Arena Veteran...

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Robert

If there is a placebo effect can there not be an anti placebo effect? I.E. Good clinically trialled ebm medicine doesn't work just because the recipient does not believe in it.

A young man goes to visit his rich uncle at his exclusive mansion. The uncle is a hard nosed no nonsense businessman who doesn't suffer fools gladly. But on his drawing room wall he has a silver horse shoe hanging. Upon seeing it the young nephew asks, "Hey Uncle I thought you weren't superstitious"? "I'm not" replies the uncle, "Then how come you have a lucky silver horse shoe on your wall" "Oh that" says the uncle, "well apparently it works even if you don't believe in it"


LoL Dave

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Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.