"Vault" of the foot

I actually think SALRE theory has more to do with the transverse plane location of the STJ axis, not the frontal plane. I really have no idea what Dennis is talking about here, somehow equating SALRE theory as being a frontal plane theory???

 

I'll give you a clue: it begins with "cr" and ends with "ap".

 

Croap? Creap? Dyslexic crepe?

 

No, it's crvaultap.

 

Simon! Take this back. I like tits! Dennis is obviously not keeping a "brest" on the biomechanical situation, but to call him a "tit" just spoilt my play time!!:drinks

 

I'm glad you posted the above reply, Kevin, as I was slowly beginning to believe I was going to have to recall every orthoses I'd prescribed and change the posting by 90 degrees as I have no idea what drsha is talking about either.

 

Kevin:

As long as we have “exposed” Wellness Biomechanics for what it is on this thread, I would like to present some observations and opinions I have with reagrds to SALRE.

The following are my conclusions after following your work and absorbing its substance from it and The Arena as best as I could over the last two years, with an open mind.

I welcome your comments and explanations in order to debate my observations.

I forgive your personal insults as I realize that I live in good company as your meanness tends to come out defensively when you are challenged over the years.

1. My focus of care in terms of examination and treatment of the foot remains on the examination and treatment of the foot. I acknowledge and have applied your work in other areas such as the lower leg, gait eval, tibial influence, etc. but have not needed to apply SALRE in my practice. I rejected it when I felt that STJ Axis was an even more random and poorly reproducible entity than STJ Neutral and virtually none of the DPM’s I have encountered utilizing it as a standard for care. I wonder if the IBC (the international biomechanics community) is determining STJ Axis Location as a part of their exam or are they approximating it as medial or laterally deviated?

2. My goal orientation focuses on treatment and my conclusions are that SALRE although it may be a sagital plane dominant theory with reference to the STJ, like Root, treats the STJ on the frontal plane with wedges and skives. You have not presented any evidence to the contrary.

3. You use a “STJ Neutral cast as described by Root et al” for your shells, yet you intimate that your work is an advance and replacement for Root and that STJ Neutral position is not measurable or optimal for many feet. You also blow off any other type of shell other than STJ Neutral out of The Arena waters? I would think you would be looking for an upgrade to Root’s Casting as exists in Ed’s or my work or the work of others?

4. Much of your work is self published like Root’s work and not peer reviewed (Precision Intracast, etc) and reflects your personal, unproven observations and theories. Yet you seem to position yourself as proven in your presentations and bravado. This leaves little room in your academic vault and teachings for anyone else’s work as you constantly prove.

5. Your Lab, Precision Intracast, where I assume you have influence as to acceptance of work and some level of financial interest, when called recently, told me, as a potential new DPM, that the preferred casting method for orthotics is Subtalar Neutral Casting. They further stated that, they would accept any casting method as a starting client to create orthotics from. That seems to contraindicate your STJ Neutral is not accepted by any quality biomechanist theory or your steadfastness to SALRE and your teachings as the way to care for foot suffering.

6. The tissue stress theory of mechanical foot therapy is not comprehensive enough to provide an exact prescription protocol for all foot pathologies yet you give exact numbers and types of corrections for prescribing, a rather weak treatment approach from my seat.

7. You state that SALRE “will allow guidance of the clinician toward an orthosis prescription that is quite likely to accomplish the goal of making the patient less symptomatic”. I have seen no evidence to justify this claim, a claim that Jeff makes for Root, me for Centering, Ed for MASS etc.

8. TSP, seems to state that if there is pain in a location of the foot (regardless of other factors) you would cast STJ Neutral and then prescribe “specific modifications” that would reduce the tensile forces in that area. That seems like cookbook treatment to me.

9. If your orthotic results in improvement when the patient returns on the first followup then you state “one could logically conclude that the foot orthosis has reduced the tensile stress within (the area of complaint), which was the original mechanical etiology of the patient's complaints”. Very scientific.
If not, you change your plan? If not enough, you modify your shell or prescription on the fly?

10. You then modify your boast by stating “of course, other potential explanations are possible, but I think those questions are best left to the researchers who have the time to explore such ideas”. You made that statement in 2006 and I do not believe the researchers have come up with evidence to defend this claim yet four + years later.

11. You also, are recreating the work of others by using new language and engineering terms to describe them which I see as an good organizational move but I believe that you are trying to lay claim to at least some of their brilliance and future fruit. Dananberg’s FHL, forefoot rocker and sagital plane blockade has worked well for me and so many others and I see no reason to convert them to your plantar and dorsiflectory stiffness approach of mechanical therapy and your claim that it is “all quite logical and mechanically coherent, as long as one understands the principles of modelling and free-body diagram analysis’.

12. You place yourself atop an imaginary pyramid when you state that “I see that the biggest problem with many podiatrists using the tissue stress approach successfully is their relatively weak physics and biomechanics backgrounds. In other words, most podiatrists don't know the difference between a stress and a strain, a moment and a force and don't understand how modelling approaches may be used to determine internal forces within the foot using only a knowledge of the anatomy of the foot and the external forces being applied to the foot”. You simultaneously demean any paradigm that does not include or involve modeling or engineering terminology from inspection or inclusion on your pyramid.

13. You continue to convert upgrades to our body of biomechanical work into engineering terms as you denounce the upgraders and lay claim to advances. I see calcaneal dorsiflectory moments coming as an ORF even now to explain the sagital plane control of the STJ as you denounce vaulting and MASS as folly. I wonder how you will eventually tackle functional foot typing?

14. Then you make the arrogant claim, totally unproven, that “the podiatrists who struggle with basic mechanics concepts will never completely grasp these ideas so that they will likely achieve only mediocre results with their foot orthosis therapy”. It is my opinion that it is your results, waiting for clinical pain to exist as a foundational tenet for care, that are mediocre.

Here is a 2006 paste of one of your postings from the pages of The Arena:
The tissue stress theory of mechanical foot therapy is not comprehensive enough to provide an exact prescription protocol for all foot pathologies. However, it will allow guidance of the clinician toward an orthosis prescription that is quite likely to accomplish the goal of making the patient less symptomatic.

For example, if it is determined by the clinician that the pain in the plantar heel is caused by increased tensile force within the medial fibers of the central component of the plantar aponeurosis pulling on its origin at the medial calcaneal tubercle, then I would design the orthosis with specific modifications that would tend to reduce the tensile force within the medial fibers of the central component of the plantar aponeurosis. This may include designing the foot orthosis with a 5 mm polypropylene shell, 4/4 degree rearfoto post, a 3-4 mm heel contact point thickness, 2 mm medial heel skive, 16 mm heel cup, minimal medial expansion thickness, a plantar fascial accommodation, and a 2-5 forefoot extension of 3 mm thick korex.

To answer your other questions, the foot would be casted in STJ neutral position using neutral suspension casting technique described by Root et al. The forefoot to rearfoot of the positive cast would be balanced so that I am not creating either an excessive STJ supination or excessive STJ pronation moments with the orthosis. I don't use "rearfoot wedging" in the orthosis since all the correction is made into the orthosis

If these specific modications then are shown at followup examination to have resulted in improvement of the condition, then one could logically conclude that the foot orthosis has reduced the tensile stress within the medial fibers of the central component of the plantar aponeurosis, which was the original mechanical etiology of the patient's complaints. Of course, other potential explanations are possible, but I think those questions are best left to the researchers who have the time to explore such ideas.

By the way, the orthosis likely accomplishes the goal of reducing the tensile stress within the medial fibers of the central component of the plantar aponeurosis by decreasing the net forefoot dorsiflexion moment and decreasing the net first ray dorsiflexion moment since the function of the medial fibers of the central component of the plantar aponeurosis is to increase forefoot plantarflexion moment and increase the first ray plantarflexion moment.

This tissue stress approach to mechanical therapy is all quite logical and mechanically coherent, as long as one understands the principles of modelling and free-body diagram analysis. I see that the biggest problem with many podiatrists using the tissue stress approach successfully is their relatively weak physics and biomechanics backgrounds. In other words, most podiatrists don't know the difference between a stress and a strain, a moment and a force and don't understand how modelling approaches may be used to determine internal forces within the foot using only a knowledge of the anatomy of the foot and the external forces being applied to the foot. The podiatrists who were engineers will be using the approach with no problem at all since it makes total sense to them. The podiatrists who struggle with basic mechanics concepts will never completely grasp these ideas so that they will likely achieve only mediocre results with their foot orthosis therapy.

And

Here is the very next 2006 posting by Simon Spooner Ph.D. from the same thread pasted:

Originally Posted by Kevin Kirby
Simon,

The tissue stress theory of mechanical foot therapy is not comprehensive enough to provide an exact prescription protocol for all foot pathologies. However, it will allow guidance of the clinician toward an orthosis prescription that is quite likely to accomplish the goal of making the patient less symptomatic.
You've made a start within this reply Kevin, I'm sure all across the land patients will be receiving this prescription tomorrow Another way of looking at this is that perhaps the prescription does not need to be as exact as previously thought to achieve the desired outcome?


Quote:
Originally Posted by Kevin Kirby
For example, if it is determined by the clinician that the pain in the plantar heel is caused by increased tensile force within the medial fibers of the central component of the plantar aponeurosis pulling on its origin at the medial calcaneal tubercle, then I would design the orthosis with specific modifications that would tend to reduce the tensile force within the medial fibers of the central component of the plantar aponeurosis. This may include designing the foot orthosis with a 5 mm polypropylene shell, 4/4 degree rearfoto post, a 3-4 mm heel contact point thickness, 2 mm medial heel skive, 16 mm heel cup, minimal medial expansion thickness, a plantar fascial accommodation, and a 2-5 forefoot extension of 3 mm thick korex.
Funnily enough I made a couple of pairs of these today , except I used 3mm EVA for my forefoot extension and I didn't put in a plantar fascial accommodation as I haven't found them necessary in the past (I made these before I read your post-honest). Now back to playing Devil's advocate Kevin, why a 4/4 post and not a 5/4 post or 6/4 post? Why a 2mm heel skive (presumably inclined at 15 degrees?- Why 15 and not 10 or 12 or some other number of degrees?) Why a 16mm heel cup and not 15?

Kevin, you know that you and I are pretty much on the same page when it comes to this stuff, but you must see it from the perspective of someone coming from the dogma of old, these are the things they want answering. I think, Howard (or maybe it was Craig) talked about viewing one model through the lens of another, and this is inevitably what is occurring, rightly or wrongly. Rootian mechanics gave a nice easy recipe to follow, and lets not forget, has helped a lot of people overcome their symptoms.

I think the point is that if we did alter the prescription you gave above, lets say we did put a 10 degree, 3mm heel skive, we, changed the rearfoot posting angle by a few degrees +/-, it may not make a whole lot of difference to our outcome. I used to describe this to students as the "treatment envelope": we treat a patient with an orthotic device and they get better thus we know our prescription worked, but we don't know just how "accurate" the prescription was to the patients requirements, it could be that we could alter the prescription quite markedly and the patient would still get better, it could be that if we alter the slightest detail ,i.e. rearfoot post by 1 degree the prescription would have failed to alleviate the symptoms. Obviously this works vice versa, if a device fails to alleviate symptoms, we don't know how far away from the success zone we are, could be that 1 degree either way in the rearfoot post would have made all the difference.


Quote:
Originally Posted by Kevin Kirby
To answer your other questions, the foot would be casted in STJ neutral position using neutral suspension casting technique described by Root et al. The forefoot to rearfoot of the positive cast would be balanced so that I am not creating either an excessive STJ supination or excessive STJ pronation moments with the orthosis. I don't use "rearfoot wedging" in the orthosis since all the correction is made into the orthosis....BTW, is "rearfoot wedging" some form of British podiatric orthosis therapy??

Just do a search in JAPMA, you'll find the term wedging is used frequently in papers published in American journals How do you know when the forefoot to rearfoot of the positive cast is balanced so that excessive STJ supination or excessive STJ pronation moments are not created with the orthosis? OK I'll stop now


These posts were four+ years ago.
Simon was evidently using STJ Neutral casting as he had no qualms with your use of it as Standard. Has he changed?

Could you please point to the evidence that has surfaced to refute any of Simon’s counter claims that he delivers as devil’s advocate (advocating against God).

Didn’t Simon write the intro to your third self published book? No devils advocate there or sheep praising sheppard.

I have admitted from day one, as Simon so meanly reaffirmed, that I am at the end of my career, that my work lacks evidence, that there are interests for personal financial gain built into my paradigm and that I continue to try to get my work recognized and accepted beyond its small following.
Things he fails to acknowledge are:
1. my accomplishmentsa as a DPM, teacher, lecturer, author and clinician

2. that the DPM’s working with my lab have increased their practice incomes by up to $150,000 annually as they profit working with Foot Centering. In addition, they claim to have added ability when it comes to practicing biomechanics and that their patients are receiving better care than they delivered before working with me.
3. there may be even a small inkling of value in my work.

Thank you for taking the time to review and react to this posting.

Dr Sha

 

Finally - an admission to what has been suggested many, many times before. No evidence your "paradigm" works and your motive is personal financial gain. No morals; no ethics and no conscience, spring to mind

Please don't.

 

Mark:

I've said these things many times before and it is not new.

I have no need to reply to them further as I feel that there is nothing wrong with them.

Mark:
Are you supporting your family with your work?
Is that your only motive?

Are we judging moral standards, ethics, etc. or comparing our work for the benefit of mankind?


I hope we can move on from there.
If not, so be it.

Dr Sha

 

Clinically, you don't need to know exactly where the axis is. Yes, it is good enough to categorize the axis position. There are papers published by researchers on using the axis and finding the axis.

It is difficult to criticize something that you don't understand. Moments are often calculated in a single plane because it easier to understand. Diagrams that use a single plane can be drawn on paper. They still can be used to understand three dimensional objects like the foot. Changing the location of force with a wedge works in three dimensions. To calculate a moment you have to know the perpendicular distance from the line of action of force to the line that represents the axis of rotation. You can find this described in any engineering text.

I use neutral position casts because that is what I have learned how to modify. There is no reason that you cannot add a medial heel skive to semi-weight bearing cast. The method of casting is not important. How you modify the cast in the lab is important.

Dennis, I will incorporate your ideas if I find them useful. So far, from what you have told us, your ideas are that the arch of the foot (vault) needs a support (centering). Depending on foot type, you may use forefoot to rearfoot measurement modifications as described by Root. This is why I kept asking you to describe how you modify casts other than what is done by Root. So, if you can't tell me why your ideas are useful then I'm not going to think they are useful.
Could you at least tell us why you use Root modifications some of the time and not others. Please don't say that it works for me. Why do you think that it works for you?

Rule 5: of the tissue stretch approach. Modify orthotic depending on symptom relief. The prescriptions that he suggests are what he is saying that you try first. Then modify later if symptoms have not resolved. So, Dennis, do all of your orthotics relieve symptoms first time? Do you do the exact same thing again if they don't?

Straw man argument. That is not what the tissue stress approach is.

No, you use the principles of tissue stress. Say, you are treating posterior tibial tendonitis and your ortohtic does relieve all symptoms initially. The tissue stress approach would say that you should increase supination moment further. The tissue stress approach would also say that a high arched orthotic may be causing the patient to use their posterior tibial muscle more because the high arch of the orthotic is uncomfortable. So, you might lower the arch of the orthotic and add a varus wedge under the rearfoot post of the orthotic. (The soft tissue of the arch is not designed to accept a lot of weight. It hurts when compressed. That is why have a problem with the whole centering idea.)

The field of engineering is quite well established. Would you remodel your house without consulting an engineer to see if the second floor is going to stay up off of the first floor. So yes we are borrowing from the work of others and applying to the foot. We also are trying to explain the success of others using engineering. In Dannenberg's case I can come up with a different explanation for what works for him. However, I usually agree with him when he says something works. Dennis, you haven't even described what you do differently.

You can't criticize something if you don't understand it. If someone doesn't understand it, it is either the student's fault (lack of effort or lack of ability) or the paradigm's fault. Engineering is quite well accepted and proven to work. The neutral position paradigm has some internal flaws that make it impossible to understand.

We'll tackle it when we find out there's more than just put an arch under the foot. Why do you change what you do for the different foot types? Don't say that it works for me. Tell us why you think it works.

I won't speak for Kevin, but I've never said that you won't get good results if you don't understand mechanics. Sometimes, a foot just needs an arch support. Knowing mechanics will help you explain why something works.

Dennis, there may be an inkling of value to your work if there is more to it than the foot needs an arch support (centering). What modifications do you make beyond those described by Root and why? Why would I prescribe one of these modifications for one foot type over the other? If you could answer these questions, I could then determine for myself if there is value to your work. If you can't answer these questions, then I will have to conclude there is nothing to your work. If you do answer the questions, I reserve the right to criticize the logic behind your answers.

Eric

 

I used neutral then. I also used weightbearing back then; ,semi-weightbearing back then; inverted then; everted then; Plantarflexed 1st ray then ; dorsiflexed first ray then etc etc What casting techniques do you use? What has this got to do with you answering the previous questions I asked of you in this, or any other thread?

Nothing mean, point of fact: you are at the end of your career.

Dennis, it's not so much that you don't have any evidence, it's that you cannot even articulate your theory.

 

No. It doesn't state that.

You KNOW it doesn't state that dennis, you must have read the TS threads. Are you deliberately misrepresenting it or do you truly not understand?!

 

How about peroneal spasm as an example? You cast the foot pronated because placing the foot in neutral results in a spastic trigger mechanism.

 

I don't understand!!!!

Dennis.

Give me a buck and I'll save you 50c!

 

Robert:
I should have said that Kevin's quote, with regards to TSP, offers one starting prescription for care for all patients with that painsince it offer a prescription for care, without any consideration for other factors.
Obviously, I have no knowledge (as you guys certainly do not have of me) of what you are all about using the meager tools offered by an online debate.

In reviewing your (in toto) work and the work of others, I use clinical care as my EBP guide.
I feel that after all your engineering and evidentiary smoke, you treat very hit and miss with no organized direction or plan, especially when it comes to casting.

How could a medially deviated STJ Axis with heel pain and a Laterally deviated STJ Axis both with heel pain, for instance, get the same starting prescription? It would according to Kevins and Simon's TSP quoted.

 

Simon:
So am I to take it that with the limited exposure that I have to you and your work and the seeming vagueness of your responses to me on this forum and your inability to answer questions point blank (like how often do you take a STJ Neutral cast in practice), my opinon of you and your work is perverse, distorted and not reflective of who you are, how you practice or what you have and can accomplish?
Ditto,
Ditto,
Ditto!

With the support of my family, friends and my academic and clinical network, let's see how far I can get before I meet my maker.
Time will tell how you write my epitaph.
and no one in my life of importance at this time will care.
Dr Sha

 

Re: vault of the foot

I, Bob Smith, took a pair of non-weightbearing negative casts and cut the right cast in the sagittal plane from the middle third of the heel through the lateral aspect of the 1st met head. I cut the left cast in the frontal plane at the apex of the "arch". These casts are from a very average appearing foot.

In the sagittal plane, the concave arch is obvious but in the frontal plane, the plantar surface of the foot is convex and sloped with an inclination angle medially. Although there is a medial arch, it is the product of the sagittal plane contour of the foot. If the sagittal plane were convex, as in a rocker bottom foot, there would probably be no medial arch at all.

Bob Smith, orphan (p.s. also no relation to Christopher Smith, DPM as I have no know relatives so please don't say I got this information from anyone else, including John Weed, et al!)

 

:good: Genius.

 

Re: vault of the foot

:good: Brilliant.

1. Was this patient casted in Subtalar Neutral Casting Position as per Merton Root, D.P.M. et al?

2. Is there a limb length discrepancy in play in this patient?

3. Is this patient (subject) available for further study?

Dr Sha

 

Re: vault of the foot

Answer to #1: I don't know who Merton Root, D.P.M. is, but evidence shows that we can't bisect the heel accurately and we don't really know what the neutral position of the STJ actually is. John Weed, D.P.M. et al did not provide us with a scientific description of neutral. In addition, since I didn't take the casts, I have no idea how the feet were cast by the practitioner.

Answer #2: I don't know, evidence shows that measuring LLD is not reliable unless large.

Answer#3: No, I randomly grabbed a pair of casts that were ready for disposal after they had been scanned for CAD/CAM and I then tossed them in the trash.

Why do you ask? I do have evidence that these are not the only pair of feet in the world.

Sincerely,
Bob Smith, orphan

 

Re: vault of the foot

Jeff:
It's bad enough that you have allowed me to manipulate you into assuming the identity of Bob Smith on The Arena.

Now you are allowing me to have you post silly responses that are out of character.

Why don't you leave that to me and Ian and Graham and Simon and Kevin and the others and go back to being Jeff Root and just keep the references to your Dad to a minimum so that we can judge you for yourself, a person who I think has much to offer.


I thought that your cast cutting experiment was at least to some extent pointed at me and The Vault of the Foot which you helped me Father, alluding to the hypothesis that it does exist.

The original thought that you put into the experiment and the time it took to perform it were spot on and appreciated.
It was thought provoking, educational and brilliant and I just wanted my questions answered before replying.

I actually have one more that I am saving that is the most thought provoking response that I have to your experiment in hope that you give me a civil reply.

If there is a thought that my questions were less than frank.

I think #'s 1 and 3 are obvious.

As to #2, I noted assymettry in your casts in that the left device, for me, had a much higher casted MLA than the right and so I was wondering if an LLD was in place? Nothing to do with The Vault.

Dr Sha

 

Re: vault of the foot

Dennis, I was just having a little fun. I do appreciate the fact that most of your responses as of late have been more serious and professional in nature. This site is part educational, part social and part entertainment. It is the educational aspect that keeps us coming back.

I may be able to retrieve the casts from the trash at the lab since I tossed them out in the office area on Friday. I don’t remember any significant asymmetry. As for Bob Smith, point well made. I will fire Bob and hire Jeff back! My thoughts this weekend are with those so closely affected by the events of 9-11.

Regards,
Jeff

 

Re: vault of the foot

My final question is one I already have the inkling of the answer but:

What is "a very average foot"?
Dr Sha

 

Re: vault of the foot

Ive also got one for you Dennis and I think I already have an inkling too .

Why is it you can ask questions and expect answers, when you never answer a direct question given to you ?

 

Like these Dennis?!:boxing:

 

Re: vault of the foot

You certainly have a valid point but like my apparent avoidance of answering quesitions there is a two way street here.

I have answered many questions and they have either been repeated or delivered more questions and in two years I have not had any apparent positive effect at The Arena.

I have tried my best not to mention my work recently, have changed my posture and my prose and eliminated the color, bold for the most part.

I have admitted my inability to answer some questions and you call them unanswered.

In addition, as I have pasted answers to Eric, they were there all the time as I stated right on the pages of The Arena.

In the opposite side, I have been told to do my own research to find answers to some of my questions. I have been told to do my homework.
Ditto.

I have listed articles, sent articles privately to Arena members, etc. in an attempt to fill in gaps.

I am comfortable with eric;'s (and anyone else's) rejection of my work)as The Arena remains the only place I have ever lectured or visited where my work is totally impossible to understand. Remember, although we have a large common ground, I reject work of yours.

I continue to question those things that remain unanswered.

As you and marc put it, I have never answered one question!!

For instance, in Jeff Root's little experiment, did he foot type the patient. Has he ever foot typed a patient? have any of you foot typed a patient?

I have tried to determine STJ Axis unsuccessfully.
I tried kirby skiving decades ago and found it of no value to my protocol.
I have reviewed MASS casting and accept that type of cast for Centring fabrication. I will not work with a Root STJ Neutral cast of any client who is not trying to upgrade for more than three casts.

When I met Jeff years ago, I added foot centering pads to the Root device that he was wearing at The Midwest and his forefoot rocker that full of fhl began to work, p longus and p tibia also began working, his knees were better positioned, his ankles were better positioned and in summary he was unimpressed with my demonstration. I have nowhere to go after that since I have no evidence as admitted

Can't we just leave it that I am old, simple minded, of mutant parents, with s**t for brains who is just picking things out from the air and even worse, I am an admitted patent, trademarking, amoral, unethical, money hungry loser . If all that be true why would anyone want to even ask me questions?

I am cured of anger and I forgive your insults and I still want to know what Graham thought of the article that I emailed him.

Jeff: answer me if you wish
Craig: answer me if you wish

I continue to learn so much at The Arena and by all your accounts, I have added nothing in return.
I think that alone deserves your raw reactions.

Dr Sha

 

Interesting!

 

Re: vault of the foot

I selected a cast with no obvious external pathology present (no rocker bottom, gross deformity, etc.) When I get some time, I will cut more to see if and how they differ.

 

Re: vault of the foot

Hmmmmm. I wonder why? Ponder.

 

I took a negative cast of a cavus foot and drew three reference lines running longitudinally on the medial aspect of the cast. I cut the cast longitudinally along the most medial line which is fairly close to the medial aspect of the shaft of the 1st metatarsal. I photographed both sections and I darkened the cut line of the lateral section of the cast to emphasize the sagittal plane arch of the foot.

I then cut the cast in the frontal plane directly at the apex of the arch and darkened the cut line. I placed a paper towel under the cast to support the proximal section of the cast so that I could photograph the frontal plane cut line which runs through the apex of the arch.

As I indicated in the previous similar example of this type of demonstration, the medial arch of foot is evident and concave in the sagittal plane but the plantar surface of the foot is convex when viewed in the frontal plane. As I said before, it is very likely that the arch of the foot is the result of the sagittal plane contour of the foot but not the frontal plane contour of the foot. Therefore the concept of a transverse arch may in some ways be a fallacy.

Jeff Root

Food for thought?

 

Jeff:
:good: great stuff.

This remains very stimulating experimentation from which we can draw much information.

Perhaps the LLA starts at the 4th met head when weightbearing and not the 5th.

This conformed by barefoot pressure studies.

The roof of the vault may not be convex as we all percieve. It obviously could be other shapes.

That is a great perspective and a great addition for you to have discovered.

I have acknowledged that you made this point previously but it was overlooked by at least some of the others.

This experiment is much more explicitive.

There are those who feel that the vault is completed when you put the two feet together forming a left and right pillar of total support for the posture.

Also, note how in your first experiment the convexity from the third line going medially is greater and deeper into the foot for your two experiments.

Finally, what was the formation of the cast from the first met to the medial surface that you cut away like on the frontal plane?
Was it more convex of did it have a dip making in lower than the medial first met frontal plane presentation.

Flat foot next?
I can;t wait.

Dr Sha

 

Dennis,

I think I became aware of this when we started to use CAD/CAM because we use frontal plane sections to modify the amount of medial arch fill, if any. I will post a CAD/CAM screen shot later to demonstrate the view. I never really thought much about it until it seemed relevant to this thread.

This is not to say that the metatarsals don't have a transverse arch. It is possible that a frontal plane section of the foot might reveal a transverse metatarsal arch while the plantar surface of the foot could be convex due to the plantar tissue structure.

This patient was someone who works at a business near the lab and I treated him as a favor over a year ago but I still had an extra negative cast of his foot sitting around. He has a plantar flexed 1st met and an everted forefoot to rearfoot relationship.

Jeff

 

Jeff and Dennis , maybe a good idea to say distal or proximal transverse arch in your discussions .

as we all know the distal transverse arch is a myth.