Foot orthoses: how much customisation is necessary?

New ground! :drinks

Is there such a beast as an "ideal" function? I contend that what is ideal for one may be pathological for another. So I'd count myself out of that working group because I think it is seeking a mythical creature in the same way as the search for the "best" type of curry or the "best" car.

In fact, thats a good analogy. What is the "ideal" car? For some its a mini cooper. For others a BMW Z4. For still others a renault Espace. We can't decide the "best" car then try to establish parameters to apply to car design to make them more like the ideal because the ideal is itself subject specific. Can't cram a family of 5 in a pagani Zonda. Can't go a quarter mile in 9 seconds in a people carrier.

So before we try to determine the ideal we must ask Is the search for an single ideal function a valid one?

Is it?

Regards
Robert

 

Graham,

Sorry to join so late in the debate, but the discussion of 'ideal' or 'normal' is one which I struggle to keep out of no matter how hard I try.

Do you honestly envisage a time when we have a list of measurements/criteria which would be considered ideal?

Despite all the points Robert has already raised regarding variation of our species, there is of course the age old issue of poor reliability/repeatability of any measurement.

Is 'ideal' simply not a very individual and specific thing? If someone is performing every single activity they wish to at the level they desire (and is doing so asymptomatically) would that not be 'ideal' for them, even if they fell outside an 'ideal range' as dictated by a working groups research?

Ian

 

Robert,

Now we re talking the same language. The search for the holy grail is always worth it. Who know's where it will take us?

But where to start?

Don't count yourself out just yet. You have just made perhaps the most valuable contribution to this debate to date.

regards

 

Yeah.....and the first time I tried to cross the street in New Zealand at my first international conference in August 1991, I almost got run over by a car coming at me from the right!!!! Thank goodness Dick Bogdan, DPM, grabbed my collar from behind to keep me from being mowed over by one of those crazy Kiwis! Now I'm very careful on "two way streets".:drinks

 

I have done lot of work with fairly elderly folks, and believe that much of what I do is "fascilitation of what's left", so that what has not worn out yet may work less painfully and for a few more years until they have finished with their feet. There is nothing ideal about this set of clinical conditions......it just is.
regards Phill Carter

 

This thread started with a challenge from an Editorial Written by Hylton:

He continued the challenge:

...and again in response to posts:

Others chipped in:

I added:

and then:

and

to which Hylton responded:

Kevin responded:

Phil responded:

Lets take up the challenge.

Here is what I propose:

1. Can we agree with my statement above in 101047 (or a modified version of it):

2. I will set up a sub forum here at Podiatry Arena specifically to discuss a consensus

3. If and when we agree on something to start from (I using my suggestion above as an eg), we then use that subforum to go through all the different clinical tests that can possibly be done that are used to derive prescription variables. We can look at the evidence; the anecdotes; the rationale; etc etc to see if we can arrive at a consensus on that clinical test indicating a particular prescription variable. If no consensus can be reached, then we note that and where the differences are.

4. Once we gone through all the clinical tests we come up with, we can then work our way through all the different design variables and what the evidence; rationale; theory; anecdotes; indications are for each of them to reach a consensus. If no consensus can be reached, then we note that and where the differences are.

5. I have registered a domain name and will set up a separate website to document the outcome of each discussion (with links back to the discussion, so modifications can be made to the consensus).

What say you?

 

Craig, I should very much like to be involved in this sub-forum. I've kept quite on this thread for reasons that will become apparent when the paper that I and others have been writing is published!

 

Hello Simon

I thought you were very quiet!

Does the paper have a title??

 

Great ides Craig and a logical development for the Arena. No reason other areas of clinical development and research can follow on a similar model. It just gets better....:drinks

 

Yes

 

Craig will this be a seperate private forum? as I would like to follow the discussion.

Cheers

Col.

 

I will admit there are many parameters that people can look at. The working group that we are talking about can perhaps agree, or suggest, which ones are the most important. We can limit those somewhat by looking at what variable in the prescription orthotic is changed. (For example, I measure standing arch height and others measure the absence or presence of equinous. Some of those who measure equinous will cast the foot in a more pronated position, which lowers the height of the arch of the finished orthosis.) So, if two different parameters effect only one part of the finished orthosis (arch height) we may be able to narrow down the research.

Once we choose a few parameters then we can move on to performing research. This is where the hard work comes in. Because there are many orthotic parameters we will have to do studies on large numbers of subjects to get trends, because some individuals will not get all of the prescription variables that an experienced clinician would add to that particular device. Or, perhaps, the subject could get two devices with many prescription variables the same on both except for one variable that changes. For example, an orthotic with all the bells and whistles with or without a medial heel skive.

I'd like to be part of the group discussing the prescription variables.

Cheers,

Eric

 

It will interesting to see if we can actually develop a consensus with the widely divergent theories that are present within the podiatric profession . It all depends on who is on the panel. As long as we don't have widely diverging opinions on how the foot works, how foot orthoses work, how injuries in the foot and lower extremity are caused, and what the goal for foot orthoses should be, then we should be fine and a consensus should easily be developed. However, having seen many theories wax and wane during my practice career, it will be a very difficult task to come to a consensus unless we can all have some basic agreements regarding the function of foot orthoses and the biomechanics of the human foot and lower extremity (i.e. pronation is not the cause of all foot problems).

 

I have no doubt what I am proposing is going to be a challenge. It will be a subforum open to all. I will activly invite people who do not normally contribute here to participate.

While I have no doubt in many areas there will be differences; but lets document those differences with a consensus as to the differences with a non-emotive statement.

The challenge will be can we incorporate things like MASS position and functional foot typing into it? and non-emotively come to a consensus on it.

The eg of how I hope this would work, is that for eg:
Lets take the clinical test of 'supination resistance' as I think this would be an easy one to get consensus on. There is stuff published on its reliability; I have unpublished data on it (eg relationship to injury etc); I think we have a sound rationale for the test; I think we can get a consensus on this test.

So the idea would be to have a discussion on this test, bring all the info and opinions we have on it together and reach a consensus --- then formulate a concise consensus statement (and this would go in the site that I will build to summarise this).

For eg (and without prempting the discussion), the consensus statement would include something like the use of supination resistance testing to determine how much force is needed from the orthotic. This is what I kept meaning earlier on about using a systematic clinical assessment to derive the prescription variables. How much force is needed is the prescription variable.

In a later discussion we can look at the design parameters to deliver that prescription variable and reach a consensus on that. eg if the decide the prescription variable of supination resistance is high, then the design parameter would be more rearfoot wedging. Assuming we first agree that this is the design parameter to deal with high supination resistance (especially in the context of the lack of evidence; but relying on a good rationale; good clinical expereince and consensus of opinion), we can then decide how best to deliver that design parameter ... or maybe not how best, but what are the options there are to deliver that design parameter (currently we have things like, rearfoot wedging a prefab; blake inverted; kirby medial skive; the DC wedge; the MOSI orthotic; etc) .... so you can see the challenge.

The threads discussing each clinical test, prescription variable and design parameter can stay open indefinitily and the consensus modified as more experience, theory and evidence becomes available.

Is this the way forward?

 

:santa2:

Properly classifying foot orthoses is a prerequisite to conducting and evaluating research if one hopes to draw meaningful conclusions about foot orthoses. I was reading this thread because there is some discussion and certainly a need to update or replace the antiquated Healthcare Common Procedure Coding System (HCPCS) codes for foot orthoses here in the U.S. It is imperative for the scientific community (researchers, biomechanists, etc.), practitioners, consumers and third parties (insurance companies, government, etc.) to have the ability to differentiate orthoses for purposes of research, evaluation and reimbursement.

There is increasing confusion amongst practitioners and/or their patients as to the nature of the foot orthoses that they are receiving. As an example, an ethical and major lab here in the U.S. sells and properly advertises a line of library orthoses. These devices were (and still are) purchased by at least one other “orthotic lab” that modifies them with posting, covers, etc. and sells them as “custom orthoses”. The owner of the lab stated in a letter to editor of a podiatry publication that “In my opinion, an orthotic is 'custom' when a negative patient model or 3-D scan is used to produce an accurately corrected shape for that specific patient's foot. Then additional customization is accomplished through the shaping of the shells and the addition of covers, accommodations, and posting. This is exactly what the System Rx method and plaster cast corrections accomplish.”

Unfortunately, if the practitioner codes and bills these devices as custom, functional orthoses (ie L-3000 code), they would be billing improperly because they are not made (formed) from a model of the patient’s own foot. This example of prefabs being sold as custom orthoses shows how clouded the water has become and how this has been taken advantage of by some. Why not just advertise these devices as library or prefabs and let the research tell the rest of the story? Is it because the prefabs are reimbursed at a much lower rate?

There is no single system of classification that serves all needs. Custom vs. prefab tell us when the devices are made but tells us nothing about the nature of the devices. Classifying orthoses as functional, accommodative, or hybrid tells us a little about the purpose of the device but doesn’t tell us how or when it is made (ie custom or prefab). The term custom has traditionally been reserved for a device that was made from a model of the patient’s own foot, but even that has changed, largely due to technology and/or deceptive advertising.

The Prescription Foot Orthotic Lab (PFOLA) has begun an effort to distinguish orthoses based on their nature of manufacture (see Technical Standards at www.pfola.org). This method is cumbersome but does give us the ability to technically differentiate orthoses. I would like to see PFOLA improve this document so I am asking for your input, advice, criticism, etc! Please feel free to contact me directly and privately at jroot@root-lab.com or on this forum.

Thank you,
Jeff Root
www.root-lab.com

p.s. Kevin et al previously provided some constructive criticism of the PFOLA document on this forum. Can someone provide me with a link to the archive of that discussion?

 

Here:
Foot orthotic terminology and classification

 

That was fast! Thanks Craig!!!

 

yes it is

 

I don't think it needs to be a goal of ours to include every casting technique or foot classification system invented by someone with a financial interest in it. in addition, our goal should not be to please everyone just because they have had some new idea. Our goal, should be, instead to work together to find a way to use the most common and accepted methods of evaluation and orthosis design techniques to arrive at optimum therapeutic design for foot orthoses.

As long as the supination resistance test is understood as having its own set of limitations then this should present no problem. However, this test needs to be used in conjunction with the knowledge that the tissue stress on one part of the foot/lower extremity will be increased when the tissue stresses are decreased by using the results of this test to design the optimum foot orthosis for the patient.

Possibly.....should be interesting to see how much fur flies in the process!:boxing:

 

As I see it we don't necessarily have to create a unified theory of foot biomechanics. We have to create individual tests and then look to see if modifications to orthoses in response to those measurements improve outcomes. For example, we have a foot with a high force needed to cause supination. We then change the heel cup of the orthosis to a more varus wedge shape and assess if that is better than a heel cup without a varus wedge.

As I understand MASS there is no underlying measurment parameter. Everyone is supposed to get casted that way. I know from personal experience that everyone should not be casted this way. I would suggest that if there is a large change in MASS arch height to standing arch height then the MASS cast might be contraindicated. Another predictor of who will hurt when wearing MASS devices might be the lunge test. Which is a similar parameter to what Root, Weed, et al. were describing when they looked at equinus and then casted the foot more pronated.

In the discussion on functional foot typing I've asked how the typing changes the shape of the finished orthotic and not gotten any ansers. If the orthotic shape is the same for each foot type, then there is nothing to study.

I don't think we are going to get a consensus on every test from proponents of each theory. In my discussions with Ed Glasser he had a problem with adding a medial heel skive to a MASS casted device. I don't see where the problem is. If we come up with a parameter to test, we don't have to have everyone on board as to it being valid. If a study shows that a medial heel skive is better for people with posterior tibial dysfunction there is no reason that you cannot add that to your MASS casted device.

It is a great way forward. We don't have to let consensus get in the way of promising ideas.

Cheers,

Eric Fuller

 

Another way to look at all this is to define the angles and dimensions af all orthoses in the same way, a top view map (which is the individual thing) with a height from the underlying horizontal plane and angle from horizontal and a specified material rigidity. I would have thought this kind of mapping was already being done by some of the CADCAM systems? Could it form the basis of a more controlled comparative system?
As far as research goes, making sure that you don't include anyone you don't fundamantally agree with in the first place is called the Hawthorn effect? or somebody elses' name I think isn't it? It kind of influences the outcome before you even start doesn't it?
regards Phill Carter