Claims of Foot Orthosis Superiority

David

To save you going over old ground you might want to check out this thread

http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=18396

Some interesting stuff there before it degenerated into name calling and hair pulling.

Kind regards
Robert

 

For those of you who do not subscribe to Dr. Barry Block's PMNews e-mail list, Dennis Shavelson (Drsha) just posted this note on the PMNews site. I just wish Craig had "better skills" and all of you weren't so mean and so deviated to Dennis so he could have stuck around to debate his "new biomechanics paradigm".

 

"Welcome to the jungle
It gets worse here everyday" - Welcome to the Jungle: Guns n' Roses
:boxing::boxing::boxing::boxing:

"deviated thoughts"- I like that a lot.

deviate
Verb
[-ating, -ated]
1. to differ from others in belief or thought

Given the lack of support found here for his belief and thought, it was surely Dennis who was the "deviant"

deviant
Noun
a person whose behaviour deviates from what is considered to be acceptable

 

Funny how DrSha interprets everyone here as seeing him as being wrong as an "untamed jungle of personal comments, deviated thoughts, and downright meanness". The critical appaisal of all approaches is put under the microscope on this site is outstanding (well done to CP for his "lack of skills"). If its worthy, it will stand up to scrutiny.

BTW, DrSha, this is a forum, not a listserve.

 

This is actually quite funny. I was not following the relevant threads and just caught up with them. To me, this foot typing does not stack up to scrutiny and DrSha is so blinded by it, that he reacts negativity to the evaluation and now goes bleating about it elsewhere rather than stay here and provide some intelligent debate.

Its also ironic that he makes claims about the lack of editing skills here. A certain unmoderated UK forum regularly bags Podiatry Arena for being over moderated and edited! I just don't get this.

 

Robert,

Thank you for the reference. I did actually see that thread but did not follow it. I can now see that yes, that thread did become quite adversarial. I am not trying to evoke a similar response from Graham; I am trying to understand his points while expressing my own and hope to learn more.

With regard to Dennis I question the professional stones of anyone who repeatedly claims "he was led here" to be attacked after becoming the apologist for all things argument (especially when he cannot back them up with one iota of empirical evidence), using less than professional language and suggesting that one member “get l**d”. I think that really sums it all up.

I suppose he felt the title of this forum was misleading. I can see how he confused it with either the 'obseqious anonymous' or the “How to Win Friends in Influence People" internet sycophant forums.


Payne's 1st Law follows the precise logic of another famous quote I am going to butcher:

Me thinketh thou doth protesteth too much - Shakespeare

 

Why would we make orthotics that we believe are not the “best available”? Do you think that your orthotics are the “best available”? I would hope that every practitioner is making orthotics for his or her patients that they honestly believe are superior to the myriad of other options they can choose.

Where exactly is your glass house? I loved your “scientific justification” for the Kirby skive. Truly humorous….. I have to say I read this stuff for the entertainment value. It is refreshing to see the scientific standard that you hold your own theory to. Impressive. How many of your articles are nothing more than expert opinion? Most by far.

If you do not have a financial interest in orthotics, I would venture to guess that you are not reading this. It would be a rare bird indeed that finds this stuff amusing. PFOLA… I wonder if they have a financial interest in foot orthotics? LOL I would guess that it has been a substantial part of your income over your whole career. Mine too. Some are just more successful than others.

I personally find this Arena a fun diversion when I am not busy doing real work. My schedule is always full and I have to prioritize between running a growing company, family, building a new research lab (we move in next week), inventing new technology, taking care of 96 employees and supervising 10 different new projects. I am having a blast.

I did consider this. We were going to pull our clients into the discussion. I just did not want to subject them to attacks. They are making people better every day with our technology. The vast majority of our practitioners have had years of experience doing things the Rootian and Kirby-esque Post-rootian brand of BS and found it came up short. Now they are getting excellent results. Research is coming out. Three articles so far from Leslie Trotter at McMaster. She openly disclosed her connection to our company and that our technology was used in each study. More RCT’s on the way from several universities. We participate, execute and fund considerable research. We have so many great new developments coming out. Our technology is improving. I consider it a real sign of health that not one of the four SSI engineers are addressing a problem with our product. All of them and the rest of our execs are working on new technology as am I.
How many RCT’s have you published about the Kirby skive? Please provide references.

In keeping with your opinion of me, I doubt that my schedule will permit me to give the arena much time or attention between now and Feb.
Please keep the personal attacks on me and my company coming in my absence. We at Sole Supports have great laughs over it. Many have looked into our technology as a result of your baseless attacks and have switched successfully to our technology. Well Done. See, even you can sometimes make people better in a round about way.
You have done a fabulous job so far.
Thanks,
Ed Glaser, DPM
CEO and Founder, Sole Supports, Inc.
www.solesupports.com
New website coming soon.

 

Sometimes....I find that you must first throw your hook into the water to get a bite.....all I need now is for Brian Rothbart to respond and I'll consider this thread a successful fishing trip.....

 

It's eerily Pavlovian eh Kevin?

 

David,

appologies for the late reply, I don't work Fridays!

And this is why we are currently no better than the high street "joe blow" orthotic guy. Anyone can use testimonials and outcome measures to demonstrate a positive outcome. Unless we, as a profession (and David), can show that we take the actual biomechanical effect of our devices seriously, we appear to the insurance industry and wider medical community, and the public, no bettre than, Rothbart, DrSha, footmaxx, goodfeet, barefootscience etc.etc.etc.

Regards

 

Down boy

What's this. A bark from Kirby's newest lapdog. :empathy:

Go fish, :sinking:

Ed

PS: Thanks for the laugh. See ya'll in February.

 

This would be the RCT which showed the MASS cast to perform better than a thin flat piece of foam in the shoe UNLESS the foam went in the shoe first?

Way to go. I'm sold. Any podiatrist presently issueing 3mm poron blanks and wondering why they get poor outcomes should seriously consider switching to MASS casting!

Sorry Craig. More meaness. I'll behave.

In all seriousness a few people seem to be missing the point of Kirbyesque biomechanics. Its not based on oucome studies. Its not based on force plate systems. Its based on PHYSICS. In another thread graham asked what certainty we have that the joints work in the way Kevin describes with moments and axis etc. This is not a model in a "do this and this will happen" sense, nor even in a "this insole cures this problem" sense. Its a clarification of how the well understood universal science of physics works in biological tissues.

You don't NEED an RCT to conclude, for example, that a heel raise will planterflex the foot. Its Physics! You know that intuitivly because of your understanding of the way the world works. The Kirby school of thought, so far as i can see is nothing more than a better and clearer understanding of this on a more detailed and useful scale in more complex structures.

But hey what do i know. Lets all go smash the spinning jenny!

Regards
Robert

PS since we're quoting songs.

" We are the angry mob. We read the papers every day. We like who we like, we hate who we hate but we're oh so easily swayed "(by any decent argument) Kaiser Cheifs


PPS, I'm poised with my bingo dabber to shout HOUSE!!!! at a seconds notice if Brian shows up.

 

"better the hound of a king than a king among dogs" - David Gemmell

Kevins work has been respected and applauded by the best biomechanical minds of our generation. I'll not bother to list them. He was there at the birth of rootian biomechanics and refined the science into the shape it is today. It is an priviledge to rub mental shoulders and cross minds with him.

So lets see. On the one hand we have someone who's work has been accepted by the likes of Craig, Simon, Dave Smith, Eric Fuller, etc etc etc. And on the other we have you. How many of your admirers would we recognise Ed? Any names we know?

Lapdogs? Here's a crazy thought. Perhaps its because he is right. And you are not. Just a thought. Think ont.

Kindest regards
Rover

 

Re: Down boy

Well hello Ed,

I think Robert's quote summed up my response succinctly:

 

David,

Just in case you guys missed this in your gang rape of Ed:bang:

David said:

And this is why we are currently no better than the high street "joe blow" orthotic guy. Anyone can use testimonials and outcome measures to demonstrate a positive outcome. Unless we, as a profession (and David), can show that we take the actual biomechanical effect of our devices seriously, we appear to the insurance industry and wider medical community, and the public, no bettre than, Rothbart, DrSha, footmaxx, goodfeet, barefootscience etc.etc.etc.

Or is it OK for group theory to bash solo theory even though neither can claim any better or worse with just clinical outcomes!

Regards

 

Graham:

I believe that you are missing the point we are making in this thread. On the one hand we have individuals who, in their zeal to make money on their foot orthosis products, say that their company's orthoses are the best, their orthosis theory is the best or make other outlandish medical claims about their company's orthoses.

On the other hand, I don't know of many other podiatrists, including myself, who has ever said that their orthoses or orthosis techniques are the best, have said that their orthosis theory is the best or have made other outlandish claims about their orthoses. If you can find anywhere in my 2,000+ postings on Podiatry Arena, in my numerous postings on the JISC podiatry mailbase, in any of my two book chapters, in my 19 published peer-reviewed scientific articles or in my 2 books where I have said the the medial heel skive or lateral heel skive (both orthosis techiques I have invented but have never made any money off of) are the best orthosis techniques available or where I have said that any of the orthoses that I have made for my patients are the best orthoses available, then please indicate these to me, because I am always careful to not make such claims in which I have no factual basis of. Both Ed Glaser and Dennis Shavelson seem to think that the only orthoses I make have medial heel skives in them where I only use the medial heel skive in about 40% of the total number of orthoses I make (80-100 pairs of orthoses a month). There is much more to custom foot orthoses than "controlling pronation".

You are right in that we need to be careful in how we scientifically study foot orthoses and that we should not make unjustified claims without scientific study. However, I don't agree with you that clinical outcomes are of secondary importance in orthosis research since without improved patient comfort and improved functional status of the patient, all the changes in gait kinetics and gait kinematics mean very little to the individuals that we all treat with foot orthoses. For example, the orthosis labs that advocate high arched, foam-bed casted, supinated subtalar joint, non-rearfoot posted orthoses for all their orthoses are really only making the same orthosis that was made over 120 years ago by Royal Whitman with their medial flange that gouged the arch of the foot so that pain would reduce the pronation of the foot. These individuals then seem to think that if they show their foot orthoses can reduce pronation in a foot, then that should be the only indicator of good orthosis function. They don't seem to understand that they are producing many orthoses that are so painful and uncomfortable for patients that they can not be worn for more than a few days or weeks before the patient gives up on them. If pronation control was the only criteria of foot orthosis function that is important, then why not just drive a long nail into the dorsal orthosis shell at the medial longitudinal arch so that the patient wouldn't want to pronate since it would cause pain?!

Therefore, Graham, I believe that good orthosis research should include both measures of clinical outcomes and biomechanical effect to shed light on the important subject of why foot orthoses produce their therapeutic effects and on how we can improve orthosis therapy for our patients in the future. Research with pain-producing, high-arched orthoses may, over the short term, improve the kinematics of the rearfoot, but will never produce the therapeutic effects of a well-designed and well-made foot orthosis that uses anti-pronation features that are well-tolerated by patients over years and years of use.

 

Dear Rover,

"The dog that rides the tractor can laugh at the snake." Dave Barry

So what you are saying is that Kevin's "respected" expert opinion supplants the need for real research. What makes someone right is who they can convince. If Kevin says the world is flat....then you agree. I believe that a former "respected" Pope once executed Copernicus for disagreeing with this theory. That fortunately did not make it any truer. :boohoo:

The application of Physics to biological systems is based on certain assumptions. Kevin's assumptions, I believe, are false which invalidates his whole theory. Of course, you and other members of the Kirby fan club, cannot afford to objectively examine the SALRE theory. SALRE theory reeks of truthiness (Steven Colbert). I will explain in detail in Feb. In the mean time, keep the attacks coming and narrow the blinders.

For the good times,
Ed Glaser, DPM
Catsup Advisory Board

 

Ed:

Nicolas Copernicus (1473-1543) was not executed by any Pope.

 

Ed's quote above provides an area for academic discussion. I remember, in my own mind, rejecting Ed's criticism of the assumptions of SALRE theory. However, I have forgotten what the criticism was. Ed, perhaps you can repeat the criticism and we can discuss the validity of it. I think it was related to joints not having axes. I am pretty sure there was more.

Regards,
Eric

When told another player had insulted him, Jose Canseco said "well, he's a three toed sloth."

The society for creative insults.

 

Ah the sweet voice of reason.

All of Ed's threads (catchy) up til now have been defending his work. To do this by attacking somebody elses is always a dubious technique.

Perhaps it is time that Kevin is challenged on HIS work. I for one would love to hear the critisms of SALRE and contrary to popular opinion i DO have an open mind on this!

I suspect that the "feb" that Ed refers to is on the colonial side of the pond. Some of us can't get there :empathy: how about you throw it open to the wider community.

I suspect that Kevin too would enjoy such a debate!

We could even set boundries. No name calling. No suggesting that the other only disagrees because their minds are made up ahead of the event. No accusations of financial partiality. Pure civilized academic discussion.

How 'bout it Ed? Would'nt it be nice to be on the offensive rather than the defensive for a change?

Kind regards
Robert

 

I have not participated in this group for a while-may,2008 so I am not really aware of the purpose of this group. All of the other proups that I participate in professionally discuss cases, problems, new products, things that I can use in my practice. I was contacted by someone that I respect and asked to review this discussion and comment.
Y'all must have way too much time on your hands!!!!or maybe just enjoy this type of bantor?? Have ya'll tried nerf bats??or maybe feather boas???
I think Kevin's response about Ed's and Dennises claims and the purpose of the topic are RIGHT ON. I am not a biomagician but I believe that the biomajic of it all is probably way above all of us at least on an individual patient basis. You egg heads can debate theory all you want, and that is very healthy for our profession.
I would propose a summit!!! Where all parties can show their research(clincal and thoeretical). Where the studies done could be closely scrutinized. One of the reasons that I never became a biomagician is that the research is tough, too many variables for my simple brain. I could always find problems in the publications (not the theory, but the methods). I applaud people like Kevin and others who continue to try to use scientific methods and evaluation to explain the theory they support.
So why don't y'all stop all of this mud slinging and get down to business?? Perhaps I shouldn't have said "business" because "business " equates with money and I don't know any biomechanical principle that is based on money. I personally believe that all those guys you see ( ie like Dr. Glaser who I use as an example because he is the only one that I personally know of) that are out their traveling around begging to give free lectures about their ideas and at the same time promoting their business are basing their biomecanical principles more on money than on any data.

But again I will hapily eat those words IF they can prove to me different.

Tip Sullivan

 

Thanks for contributing, Tip. I asked Tip to be involved in this discussion since I wanted to get more American podiatrists involved to get their input on what we are talking about since the individuals we are talking about are functioning within the American podiatry system. Tip was a biomechanics student of mine, three years behind me at CCPM, practices in Mississippi and is involved in the podiatric politics in that state.

Tip, what theories of foot biomechanics/foot orthosis therapy are most popular in Mississippi?? Is there much interest in biomechanics/orthoses in your area, or is it mostly surgical? I know you are primarily a surgeon, but you were pretty good at biomechanics also, from what I remember.

The mud-slinging is getting a little old and it really should end in this type of forum. Thanks for pointing that fact out to me, Tip. Sometimes I get a little excited about these types of things.....you know how I got back at CCPM when we started to discuss biomechanics.

 

Kevin,

Always a pleasure to read your words, and I too am as distressed at the comercialization of foot orthoses, using tempting but misleading advertising to draw clients in.

you wrote:

Agreed, but how do we compare orthoses to orthoses where "clinical outcomes" appear to be the same. What "biomechanical effects" should we be testing and how can we do this with reaserch that makes it clinically applicable?

Regards

 

Depends on your perspective and what you a trying to achieve. For example: in surveying, triangles with internal angles that add up to 180 degrees are employed, yet we know that the internal angles of a triangle don't add up to 180 degrees on the surface of a sphere. Perhaps you missed your calling and should be trying to right the wrongs of the surveyors who been dealing in mistruths for years.

See this:
http://en.wikipedia.org/wiki/Flat_Earth

 

RE: Theories

Here's some food for thought..

Theory & Law​

A scientific theory or law represents a hypothesis (or group of related hypotheses) which has been confirmed through repeated testing, almost always conducted over a span of many years. Generally, a law uses a handful of fundamental concepts and equations to define the rules governing a set of phenomena.

Scientific Paradigms

Once a scientific theory is established, it is very hard to get the scientific community to discard it. In physics, the concept of ether as a medium for light wave transmission ran into serious opposition in the late 1800s, but it was not disregarded until the early 1900s, when Einstein proposed alternate explanations for the wave nature of light that did not rely upon a medium for transmission.

The science philosopher Thomas Kuhn developed the term scientific paradigm to explain the working set of theories under which science operates. He did extensive work on the scientific revolutions that take place when one paradigm is overturned in favor of a new set of theories. His work suggests that the very nature of science changes when these paradigms are significantly different. The nature of physics prior to relativity and quantum mechanics is fundamentally different from that after their discovery, just as biology prior to Darwin’s Theory of Evolution is fundamentally different from the biology that followed it. The very nature of the inquiry changes.

One consequence of the scientific method is to try to maintain consistency in the inquiry when these revolutions occur and to avoid attempts to overthrow existing paradigms on ideological grounds. ​

So, let;s consider dropping the word theory and stick to the word, idea.

RE: Current Ideas in Podiatric Biomechanics

As a Biomechanist (and someone in the Lab industry), I realize that we have several great ideas that have been proposed by Podiatrists and PTs. In the Biomechanics Lab we are challenged to analyze these ideas in three ways: 1) dynamics of the foot are extremely difficult to quantify given the complexity of the anatomy; 2) relatively speaking there are too few researchers working in this area; and 3) obviously footwear creates a physical challenge when measuring the movements of the foot and its many segments. The good news is that multi-segment foot models will help answer questions about the Sagittal Plane Facilitation Idea and, perhaps, the ideas of Ed. To date, the work of Kirby has been analyzed to the greatest extent and it has been supported by Mundermann, Williams and our work that the frontal plane moments about the ankle are, in fact, influenced by custom foot orthoses manufactured by Root methodology and accredited laboratories.

The concerning issue is how these ideas are presented to clinicians who may not be trained as critical thinkers. For example, on more occasions than I care to share, I have listened to clinicians pontificating about their idea(s) without a shred of empirical evidence to back up their definitive statements. Often, they: 1) suggest that all that you think you know is wrong, 2) they tend to cite a few papers that support their idea but do not reveal the results from other papers that do not support their idea; 3) they cite papers from magazines; and 4) presentation style is offensive and misleading, to say the least.

With the PFOLA conference, we purposely bring the best from the scientific and clinical sectors togther. It is an understatement to state that the two communities need each other equally to ask great research questions and to conduct excellent science.

 

Unfortunately, here in MS we have no major biomechanics guru----BUT----we see probably more adult flexible flat foot than anyone in the nation. I use the basic biomechanical priciples that I learned under kevin every day-the biomechanics don't change but our explanation of them does. In fact I find myself using fewer "custom made orthoses" which most of my patients can't afford and doing sometimes very innovative padding on OTC devices--I think that I have learned as much by trial and error than by reading biomechanical principles.
One issue that I like to discuss when I am invited to talk on this subject is balancing the use of biomechanic principle with functional surgery. Please understand that of course 99% of my symptomatic flat footed pts or the referals get a good dose of fuctional (Rootarian) orthoses before they have to go to surgery. One of the issues that, over the years I have found to be poorly explained is the use of planal dominance in the choice of procedures used to stabilize the lateral column during flat foot reconstruction. My experience has taught me that during surgery this particular debate can be chuncked out the window. The goal is to get the lateral column locked with the calcaneous in the correct position wheather I use an evans or an arthroeresis device is not the concern the goal is the same. Over the years I have found that I am leaning more toward the arthroeresis due to the morbidity advantage but in some feet (rare) the lateral column just will not lock up adequately with an implnt regardless of size. Before I make that incision to put in that sizer it would be nice to know if it will work or not. I would certainly like to hear some or better yet see some collaborative effort between biomajic gurus and biomechanically minded surgeons.
Remember Kevin--that was one of my biggist gripes at CCPM when I tried to get the school to require a full biomechanical evaluation for every surgery patient and I think it still occers in podiatry-the gap between biomechanics and surgery. we need to get someone like Kevin (a scientifically minded biomagical guru) hooked up with Al Burns or Steve Palladino (scientifically minded surgeons) and apply the "principle of biomechanics theory" to the practicality of surgery. Developing a long term prospective study that intercalates biomechanic principle with some of the more simple or even the complex surgical cases is sorely needed and could be undertaken on a multisite basis using our schools and/or residency training for the data.
There I go again-should a, would a, could a!! Mississippi is a long way from any of our schools but I would be willing to participate in some sort of well designed study and I bet there are lots of other like minded pods out there---perhaps a forum like this is a way to help bring them together.
Tip

 

Chris,
:good:

Regards

 

Kevin,
You are correct. Perhaps I confused Copernicus with Galileo who was forced to abjure heliocentricism, was imprisoned and later spent the rest of his years under house arrest for a theory, which turned out to be mostly correct. The point here is that "respected" authority figures can easily be wrong. In other words, gaining the respect of experts does not in any way replace scientific investigation nor does it guarantee correctness. Nor do credentials or publications that are entirely "expert opinion". You are a theorist. I believe that your theories are wrong. I am a theorist also. Our theories conflict. Thus far there is no real evidence that your theories are right however I applaud you for participating in research and I am funding some, and doing some of the research to prove my theories are correct. May the best theory emerge as correct.
Ed

 

No problems with bias there then :bash: Oh dear, research methods 101

Hint: this statement has nothing to do with the bit about funding or doing the research, it's all about "to prove my theories are correct"

 

Interesting....sounds like:

5. When they feel they need further support to counteract the arguments of the the "nonbelievers" of Podiatry Arena, they contact their friends and ask them to start posting positive comments regarding their orthoses on Podiatry Arena.


Ed

 

This is exactly the crap I'm talking about, above.

When are people going to start respecting that different clinicians have different approaches/strategies whether its FP, SP, or Ed's idea. First and foremost, we are dealing with three dimensions, and secondly, perhaps each idea can be applied depending on what the patient presents with. Maybe we should concentrate when a patient would best benefit from a SP-type intervention; or a MHS-type intervention, etc, etc.

This, May the best theory emerge as correct, is just weird.

 

Mac, I've said this many times before and I'll say it again. I like to paint my pictures with all of the colours all of the time. In other words, I use as many theories as I possibly can when approaching a patient.

The only point I disagree with you on is the number of dimensions Hope time isn't passing by too slowly for you?

Best wishes from the T.A.R.D.I.S.
http://en.wikipedia.org/wiki/TARDIS

Which gives rise to a good thought about ALL contributors here, let's hope we are all bigger on the inside than the outside.

 

Simon:

You crack me up....:drinks:drinks

 

Cheers Big Boy:drinks:drinks

 

Kevin, Eric and Robert,
I would love to have this discussion. Even though I am quite busy, I will do my best to participate under the ground rules that Dr. Isaac suggests.

We could even set boundries. No name calling. No suggesting that the other only disagrees because their minds are made up ahead of the event. No accusations of financial partiality. Pure civilized academic discussion.

Instead of worrying about my motives (which only I am privy to) or my financial success or what I have read (which again only I know) lets talk about the real issues here: foot biomechanics.

Allow me to begin with a question:

According to the SALRE theory.....In the medially deviated STJ axis, the majority of the MLA is lateral to the axis. If a vertical upward force is applied to the plantar surface of the foot with its COP in the MLA, then according to the SALRE theory, being lateral to the axis, it will have a pronation moment. However this force will raise the MLA and therefore supinate the foot.

How can a force directed upward in the MLA which in the SALRE theoretical model causes a pronation moment, result in supination? or more simply: How can an upward force with COP in the arch result in a pronation moment?

Please clarify,
Ed

 

Ed, Let me make this crystal clear! Kevin did not ask me to support his point in this discussion he simply asked me to comment. My comments are made based upon my previous experience which includes listening to most of the participants "theories" and what I have seen and experienced in 20 years of practice.
This appears to be simply a bitching session-why don't yall (all of you) try to do something positive?? discuss material and methods , discuss your data, collection methods, how you controlled it, the pros and cons of your own work. Something of value that we all can use--not money , not ego

Tip

 

I have to thank every one for contributing to this discussion. Apart from some of the personal attacks, its incredibly valuable to help one become more critical of what one does in clinical practice and reads about biomechanics.

What jumps out at me from this thread is:
Theory with a commerical product attached vs theory with no commerical product attached

 

Ed, I can speak from experience here. I have a quite medially deivated STJ axis foot. I was an outlier subject in Kevin's study on palpation of the location of the axis. When someone takes their finger and pushes up on my medial arch except for around the navicular tuberosity, my foot pronates. This occurs because the force applied is lateral to the STJ axis. That is the explanation. You can go deeper into finite element analysis for a deeper explanation of how forces in the arch can cause a pronation moment. The direct observation of the finger pushing on the arch is hard to refute.

When I stand on high arched devices, I get pain in my arches. I have tried to getting used to high arched devices by slowly increasing the time worn. The last time I tried this the pain in my posterior tibial tendon woke me up at night. After stopping wearing the devices for long enough to recover, I added several layers of moleskin to the medial side of the heel. There was increased time before the pain started, but I did not try to wear them further.

The point of this story is you have to explain how the arch gets higher when you stand on top of a high arched device.

Let's start with some hypotheticals. You take a block of wood and put in on a high arched device. Will the arch of the block of wood get higher? No because the high arch device cannot exert enough force on the ends of the block of wood to pull the ends down to make an arch.

Next hypothetical curved flexible piece of plastic on top of high arced device. The curve of the arch of the piece of plastic is not as sharp as curve of the orthoic. If the force is applied above the arch the orthotic will not curve around the orthotic becasue nothing is forcing the ends of the plastic to bend around the arched device.

Ed. When a foot stands on an orthotic with a high arched device what pulls down the thends of the foot to make the arch higher. The only option that I can think of, in which you could bear significant amount of weight on the heel and forefoot is the muscles. That would explain the extreme muscle soreness one sometimes gets when wearing high arched devices.


Ed, Please clarify the folowing,

How does pressure on the soft tissue structures of the arch raise the arch?

How does raising the arch cause supination of the STJ?

Explain how the foot acts differently than the curved piece of plastic.

Regards,

Eric Fuller

 

Ed and Other Distinguished Colleagues:

Nice to have a more civilized discussion of a topic that I am still fascinated with after all these years.

As Eric stated, if the subtalar joint (STJ) axis is significantly medially deviated (e.g. it exits the medial foot superior to the medial aspect of the naviculo-first cuneiform joint), then if a force is applied in a superior direction from your hand, or from an foot orthosis to the medial longitudinal arch (MLA) but this force is lateral to the STJ axis (e.g. base of the 2nd metatarsal), this MLA force will cause a STJ pronation moment. There is no denying this mechanical effect since it is based on Newtonian mechanics.

Your question is a good one though and it is one that I have been asked many times before. The same force (i.e. plantar to the 2nd metatarsal base) acting in the MLA of the foot that tends to pronate the STJ may have also a MLA raising effect since, by applying a compression force to the soft tissues of the medial arch, there will be both a rearfoot dorsiflexion moment and medial forefoot plantarflexion moment. In other words, the MLA force, acting lateral to the STJ axis, will both be attempting to pronate the STJ but also,at the same time, be trying to raise the MLA of the foot. These effects can be clearly shown using modelling techniques and seem to correlate with what we often see clinically occurring in the orthosis treatment of more significant medially deviated STJ axes such as the case in posterior tibial tendon dysfunction (I treat approximately 10-15 of these patients a month in my practice).

The higher arched orthosis can have a very significant effect in creating a STJ supination moment and works to increase STJ supination moment by redirecting ground reaction force (GRF) from a more lateral aspect of the plantar foot to a more medial aspect of the plantar foot. The force from the higher arched orthosis plate does not actually even need to be acting medial to the STJ axis in order to reduce the STJ pronation moment acting on the foot since all it need to do is shift GRF from lateral to medial on the plantar midfoot in order to effectively produce less STJ pronation moment. In other words, using the concept of rotational equilibrium, there is no mechanical difference between a decrease in STJ pronation moments and an increase in STJ supination moments.

To better illustrate this example (for everyone following along), take, for example, a see-saw with equal length of board on either side of the axis of rotation of the see-saw balanced with two boys on each of the board, each weighing 100 lbs. If one desired to produce a clockwise rotation of the see-saw, then one could either increase the downward force on the right hand side of the see-saw by handing a 25 lb weight to the boy on the right hand side of the see-saw (increase the clockwise moment of the see-saw) or have the boy sitting on the left side of the see-saw get off the see-saw (decrease the counter-clockwise moment of the see-saw). In other words, both mechanical alterations to the see-saw would produce the same mechanical effect, an increased tendency to produce clockwise rotation of the see-saw. Therefore, contrary to popular myth, the orthosis does not need to be pressing medial to the STJ axis in order to produce less pronation moment, it simply needs to either reduce the magnitude of STJ pronation moment or increase the magnitude of STJ supination moment.

Therefore, I have no problems at all with higher MLA orthoses and have used this foot orthosis modification routinely in my clinical practice for over the past two decades in order to increase the STJ supination moment and also increase the MLA raising moments to produce the mechanical effects and therapeutic effects that are necessary for the patient. However, I have also found that using inverted heel orthosis techniques, such as the medial heel skive or Blake inverted orthosis technique work even better when used along with a higher MLA orthosis because the resultant orthosis will be more effective at producing STJ supination moments and improving the orthosis comfort in the selected patients I use these techniques in.:drinks