STJ neutral and Forefoot deviation

HI Jeff, I think most would agree that drawing on the foot in any form is not repeatable, but I beleive the difference is what we do with the results of these "measurements" from skin markings.

In my understanding (and I´ve only read the bible once I guess most have never read it and will reading it again sometime in the future), these measurment paradim of what we refer to as ´Root´mechanics was very specific with measurments and with cause and effect. The level of say Rearfoot control was in 1 degree increments, and due the the problems of practitioner variability and then lab " changes" to the cast, made the whole process not very a bit hit and miss in regards to the degree of RF control required.

Yes marking the STJ axis is the same, but what I gives us is an indication of the STJ axis being medially or laterally deviated in general over the gait cycle. What this gives us is an indication of where the force from the orthotic should be, ie medial or lateral.

But an maybe it´s just me it´s just an indication and only a small part of my orthotic make up script.

What is more important is what tissue is understress, why that tissue is understress and how my treatment which may or maynot include orthotics can reduce the stress on the tissue.

I maybe draw on peoples feet once or twice a week these days, but again maybe thats just me.

as an aside I still use many `Root`techniques as they we taught too me 15 years ago along with other `techniques` depending on what I decide the patient needs.

as an another aside a question this time, Does your lab make Skive orthotics ? or do you use them ? if so how do you decide to use them or not ?

Just an intersted party on the biomechancis journey, no malice intended .

 

How can you hope to justify diagnosis, treatment protocols, research, valid evidence, clinical protocols, etc. that has importance, reproducability and teachability upon these admittedly flawed, unscientific and non researchable STJ Neutral and STJ Axis measurements (we are not even arguing their relevance)?

It is all BS!!! (Tower of Babel Biblical Reference).

The intelligent reference in the above quote is to call Root's Text a Bible and I'm sure Kirby's Letters have been called Biblical as well.
They both try to provide an answer to understanding the wonder of human lower extremity biomechanics which may well remain unanswerable.

They are faith based arguments and the comparison should be to religious fundamentalists not Newton, Darwin and engineering. They are built on ideology and opinion and not fact.

Winning is the goal of each paradigm and not assimilation, integration and concensus.

Both paradigms take a BS measurement without strong reference or evidence, take a BS Negative Cast without strong reference or evidence, adjust the cast positive differently without strong reference or evidence, prescribe from clinical judgement without strong reference or evidence, dispense and instruct without strong reference or evidence, monitor without strong reference or evidence and then ask the biomechanical world to accept one of them totally and blindly as scientific and acceptable to incorporate into EBP.

Even worse, when other poorly referenced and evidenced paradigms surface, they use their orthodoxy to dismiss them by asking them to produce references and strong evidence before even examining them for possible growth and advance to the body of biomechanics.

No wonder biomechanics is not being Mastered as per Dr. Kirby's Article which he has so kindly referenced on his password protected site (counting sheep Kevin?).
Maybe The Arena should be password protected too?

Summarily, STJ Neutral is BS and STJ Axis is BS, Rearfoot to Forefoot Relationship is BS, MALRE and FALRE don't exist yet.


Where do we go from here?


Battlelines or Living Peaceably?

Just an intersted party on the biomechancs journey, no malice intended.

Dr Sha

 

Do you mean functional orthoses with a medial or lateral heel skive modification? If so, yes, we use medial heel skives on a regular basis when prescribed by the practitioner. We rarely get requests for lateral heel skives. Is that your question?

 

Forefoot to rearfoot does not answer every question we have nor can it help us explain all symptoms. Therefore, if we examine a patient and determine that the ff to rf relationship is not a significant clinical finding or indicator, we can look at other factors. This is called a pertinent negative. If however we see a ff to rf that may be of some functional consequence, perhaps we can use that information to help develop a diagnosis or to help us determine how to cast the foot or manufacture an orthosis. For example, many practitioners today are "casting out ff supinatus" when casting the foot. How can you cast out supinatus if the patient doesn't have a forefoot supinatus (which by definition, is an acquired inverted position of the forefoot that is support by soft tissue contracture)? What if you don't look at ff to rf and the patient has a significant plantar flexed 1st ray deformity (i.e. condition)? What happens if the practitioner plantar flexes the 1st ray even more by "casting out ff supinatus" in this patient? I believe this would be contra indicated in this patient.

I did previously answer your question about what Dr. Root was attempting to measure. It was the net ff to rf angular relationship that resulted primarily, but not exclusively from motion and position of the midtarsal joint. He recognized the contribution of the other joints that influenced ff to rf but acknowledged in this book somewhere that we could not differentiate or measure their motion or contribution clinically (i.e. something to that effect). I will see if I can find the comment in his book.

 

Jeff thats what I ment, It´s been my understanding that you treat patients as well, so The 2nd half of the question was more directed at you in person.
ie do you use them? and how do you decide to use them?

 

Robin:

I have been purposefully staying out of this discussion, for reasons which are probably obvious to Podiatry Arena veterans, but think I need to at least try to provide you with an answer which is compatible with over my years of research, observations and thoughts on this interesting subject.

From my personal perspective, I feel I can reproduce the subtalar joint (STJ) neutral position to within +/- 2 degrees accuracy. I also feel that I can reproduce forefoot to rearfoot measurement, as described by Root et al, to within +/- 2 degrees accuracy. Just because a number of examiners can't agree with each other on STJ neutral and forefoot to rearfoot measurement, this doesn't also mean also that a single examiner can't be reasonably accurate within themselves to be able to detect slight variations within the structure of the foot and lower extremity of the human population to make valid clinical assumptions regarding the stucture of each individual's foot and lower extremity.

If you look at most of the research on Root et al measurements, it seems that when only one experienced examiner is asked to repeat the measurements and compare them to previous measurements they had made before, then they can be fairly accurate within themselves. However, when asked to compare inter-examiner measurements (between one clinician and another) the Root et al measurements don't seem to be very accurate at all. This is probably true of most clinical measurements we make.

Off to see patients now.....I'll continue later.

 

So you are admitting a personal 4 degree error in STJ Measurement.
and a secondary personal 4 degree error rate when then measuring rearfoot to forefoot.

and that gives results that are FAIRLY ACCURATE? :sinking:

I can only begin to imagine the inaccuracy of those less skilled than you!!

and in addition Robin, Jonah came out of the whales belly and Moses faced a burning bush that did not burn up. igs:

Oh, and whats your error rate on STJ Axis measurement Kevin. (with or without using one of the 2 or is it 4 measuring devices)?

Dr Sha

 

Dennis,

I´m notsure whats gotten into you today, but I´m not really sure that this is the way to go about things.

You may feel hard done by because people don´t think foot centering and foot typing is the way forward, people are able to make their own decisions.

I don´t know you at all or what you are trying to achieve, but I think your blood pressure must be quite high.

Maybe a Podiatry Arena timeout maybe the best thing - relax a bit, get the stress levels down.

 

In addition Kevin, are you saying that when taken in groups, our examinations could never produce multicenter or multiclinician studies worth the keyboards thay are pounded out on?

Dr Sha

 

There are really two questions here. When and why would I use them in treating a patient personally; and when and why would I recommend them when conducting an orthotic consultation with a client of my lab?

On a personal level, I firmly believe in keeping it simple. Less is more! The negative casting process, basic cast modifications, and basic functional orthotic can accomplish a lot, so I try not to over complicate it. However, every orthotic should be prescribed to meet the specific needs of an individual patient. Therefore, each prescription option or variable should be based on logic and reason.

For example, I would not typically use a heel skive unless I was using a deeper heel cup than standard because I am using it to achieve better control. I might also use any or a combination of the following: less medial arch fill to create a higher arch orthosis, a zero degree rearfoot post, a medial rearfoot post flare, a wide arch profile (i.e. medial flange), invert the cast, etc., depending on the symptoms, how severely the foot appears to be functioning, the patient's lifestyle, occupation, activities, goals, and how much relative pronation force I feel I need to get the proper level of control to accomplish our treatment goal(s).

For example, if on weightbearing the individual experiences abduction of the forefoot on the rearfoot, significant heel eversion, medial bulging of the talus or the talus and navicular as a unit, and significant pronation related symptoms, I might throw the book at it in terms of functional control measures. After you treat enough feet, you get a sense of relativity for what you can achieve and how much control you believe may be necessary to accomplish your goals and objectives. Clinical intuition is closely related to clinical experience.

When conducting a patient case consultation with a practitioner, I have found that it is important to find out how aggressive or conservative the practitioner is, how much they are willing to deal with orthotic adjustments or modifications, etc. I attempt to understand their treatment goals before I render my opinion. I may try to get the practitioner to modify their goal if the practitioner seems to be too conservative or too aggressive. For example, today I encouraged a doctor to use a hybrid device for a non-diabetic patient with peripheral neuropathy and a small, open sub 4th ulcer. The doctor was considering using a more traditional, functional orthosis and I convinced him that a hybrid device would likely provide adequate functional control and support the forefoot supinatus in order to reduce the overload of the lateral forefoot; and that we could accommodate the ulcer in the top cover as well.

So I really don’t have a simple answer for your question and I don’t have a cookbook approach. If the stj axis is medially deviated, then a heel skive might be in order. But I also rely a lot on open chain examination of the foot’s range and direction of motion at the stj, mtj, ankle joint, 1st mpj, 1st ray, etc. I also rely heavily on a visual gait analysis, patient history, etc.

As a rule, heel skives are well tolerated. I do hear practitioners say that our lab's skives are more pronounced and generally more effective than some of the other labs they have used. We don't water them down, so they should only be used when needed because they can produce discomfort, especially if the patient lacks the proper rom. To me, that's a clear sign that we are actually altering forces.

 

Now that I'm done with patients for the day (only saw 28 today), I will continue....

My belief is that until we have a better replacement for a midrange position within the STJ range of motion other than Root's neutral position, then the STJ neutral position is the STJ position which we should use when referencing measurement parameters such as forefoot to rearfoot relationship. In additon, from 25 years of clinical experience of making over 13,000 pairs of custom foot orthoses, I believe Root's neutral position is the best rotational position by which to position the STJ during the making of custom foot orthoses for about 90% of patients.

On the other hand, does one need to measure the STJ neutral position to make an excellent orthosis for a patient? Certainly not. Does one need to measure the forefoot to rearfoot relationship of a patient to make an excellent orthosis for that patient? Certainly not. However, should one determine the approximate STJ axis spatial location in the patient's foot during weightbearing activities in order to better appreciate the prevailing STJ moments occurring within the foot so that the best functional orthosis can be prescribed for the patient? My opinion is, definitely yes.

And, Robin, you must remember that STJ axis spatial location is very different from STJ rotational position, once you reach a point of where you are starting to get your head around this relatively complicated, but important, subject. I have attached two of my papers on this subject which you should read in chronological order so that you may better appreciate the significance of the difference between STJ rotational position and STJ spatial location.

I will be happy to answer more of your questions once you have read these papers.

 

Robin:

I have time now for one last installment in order to answer all the questions asked in your initial posting.

Since using subtalar joint (STJ) spatial location as a reference relies on having the plane of the forefotot parallel to the ground (or parallel to the simulated ground-transverse plane during open kinetic chain examination) then the Root et al measurements of forefoot varus, and forefoot valgus will directly affect STJ spatial location.

For example, if we have three identical feet with the only exception being that one has a perpendicular forefoot to rearfoot relationship, another has a 10 degree forefoot varus deformity and the other has a 10 degree forefoot valgus deformity, then each of these feet will have different STJ spatial locations if we determine STJ spatial location in the non-weightbearing setting.

The foot with the forefoot varus deformity will have a STJ axis which is medially deviated and the foot with the forefoot valgus deformity will have a STJ axis which is laterally deviated relative to the foot which has a perpendicular forefoot to rearfoot relationship. This will occur because the plane of the plantar forefoot within the patient's transverse plane is the reference for determining STJ spatial location in the non-weightbearing examination method I first described 23 years ago (Kirby KA: Methods for determination of positional variations in the subtalar joint axis. JAPMA, 77: 228-234, 1987).

Therefore, Robin, the STJ spatial location measurement/refernence system that I have been writing on and lecturing on for the past 23 years can be directly mechanically linked to the measurement system that Mert Root and his colleagues described over 40 years ago. I view these two different foot measurement systems not as one measurement system that is better or shoud replace the other. Rather I view them as being two distinct foot measurement systems, each with their own strengths and weaknesses, but with two very different frames of reference: the Root et al system, the frame of reference is the STJ neutral rotational position, while in the system I have described, the frame of reference is the STJ axis spatial location relative to the plantar foot.

Hope this helps.

 

Originally Posted by drsha View Post
So you are admitting a personal 4 degree error in STJ Measurement.
and a secondary personal 4 degree error rate when then measuring rearfoot to forefoot.

and that gives results that are FAIRLY ACCURATE?

I can only begin to imagine the inaccuracy of those less skilled than you!!

and in addition Robin, Jonah came out of the whales belly and Moses faced a burning bush that did not burn up.

Oh, and whats your error rate on STJ Axis measurement Kevin. (with or without using one of the 2 or is it 4 measuring devices)?

Dr Sha


In addition Kevin, are you saying that when taken in groups, our examinations could never produce multicenter or multiclinician studies worth the keyboards thay are pounded out on?

Kevin:

When will you answer these questions instead of gloating that you saw ONLY 28 patients or were on vacation, or lectured in a far off location or wrote so much stuff based on your own personal experience (Level 5)?

TSA has offered little as to strong evidence useful in EBP.

TSA is inferior clinically to some of the other paradigms becasue it is incestuous, lacks teachability and with you as leader, each practitioner can only hope to gain interpractice skills and I guess, someday, be as close to you as they can get if they follow your dogma by your own admission.

I quote Kirby and Payne and Spooner and Dananberg and Glaser and Root amongst those that have advanced (or are holding back) biomechanics all the time in my writing and lectures. My work has and will continue to grow incorporating the work of others in EBP. None of us but you have a personal password protected site.

Kevin:

Have you been entrepeneurial in marketing yourself for profit locally, nationally and internationally in order to take care of you and your family that has resulted in you seeing ONLY 28 patients yesterday? You choose the limelight but in 25 years (or my 40), you (or I) have yet to convince the DPM's of your (our) net worth as a leader (nor have I).

p-ersonally, I have made over 25,000 pairs of foot orthotics in a forty year career and obviously, that does not make me better (or worse) than you. In addition, I have performed over 4000 bunionectomies, I have closed over 5000 wounds, I have treated over 10,000 athletes and dancers. I have monitored 15,000 or more diabetics throughout their disease. What are you trying to prove with your boasts?

I think we can agree that the best years for biomechanics lie in the future.

For me, the recent days have exposed the fundamental bias and flawed science that exists on The Arena so well summarized by Robert and Eric and Kevin on this and other threads for what it is.

Can't we calm the waters and level the playing field by admitting that none of the current paradigms has validity, reproducability or the evidence to justify scientific acceptance so that we can reduce the fundamentalist bias that exists here and elsewhere and the future is up for grabs OR we can work together and meld philosophy for the good of the foot sufferes all over the world.

Please address my simple questions as to the error rate and teachability of your work or by selectively avoiding comment (The Arena Veterans Know What I Mean) help to make my statements regarding the value of your work stronger.

Dr Sha

 

I thought I would post this link as an example of how frontal plane heel position and forefoot to rearfoot relationship relate to surgical correction of the foot. http://footandankle.mdmercy.com/conditions/higharch/charcot_marie_tooth.html

Without a sense of "normal" or "ideal" biophysical criteria, how can you decide if and how to operate on these feet? My point is, I feel that some of you are taking for granted the benefit and power of your knowledge but it becomes far more evident when we look at extreme examples. So if I measure the ff to rf and a patient with fasciitis has a five degree everted forefoot position, so what. But what about a patient with CMT who stands with their heel inverted 18 degrees to the floor (but heel bisections aren't accurate you say) and has an everted ff to rf of 22 degrees (but ff to rf measurements aren't repeatable you say) and needs a calcaneal osteotomy and 1st met osteotomy? These corrections rely on the same planes of measurement and essentially same criteria for “ideal” that we use for foot orthoses. So while the margin of error is always an issue, the application in these extreme feet does help to explain the rational of the underlying system.

 

Jeff:
All your spinning is based on you Dad's work which is being challanged by new paradigms that differ. While your quote rings of orthodox truth to those indoctrinated, that doesn't, make it evidence based or engineering appropriate or scientific when a practitioner with a 4 degree STJ Neutral error rate and a four degree rearfoot to forefoot error rate makes a clinical judgement and calls for a four degree rearfoot varus post or Kirby skive claiming accuracy and custom care.

As I have said before, we are all Charlatans, you are just bred from the Merlin Line and so you can claim authority but you can't prove it any better than I.

Dr Sha

 

It does Kevin. Many thanks. I have already read your papers as posted above and will be re reading them again. I have had the last two days at a trade fair and haven't had time to go through all the posts and try to understand them but I am grateful to all those who have responded constructively.

I hope to have some further pertinant questions soon.

Regards,

Robin

 

Hi Dr Sha

I notice you keep on about Kevin’s statement that he has a +or- 2° error in both his stj and ff to rf measuring. I believe that the way you repeat it and use it as a weapon to beat-up both Kevin and Jeff shows a lack of understanding of the theory of working within tolerances. Kevin said he has an error of 2° either way. You repeated that as an error of 4° and that’s not what he said. You also seem to be implying that Kevin could and indeed may often compound one 4° error on top of another giving an 8° error.

There is a range of error of 4° but the deviation is not more than 2°. Neither is the range of occurrence even and random within that range but rather it is in the shape of a bell curve with the error getting rarer as it gets greater and the majority of error within 1°. That 2° error could occur although statistically it would be seldom and it could be compound it by an additional 2° in the same direction but that would be rarer still in a way that a bell curve compounded on a bell curve makes a narrower bell curve not a wider one.

In practice, and Kevin did say that this was in a practical context, the majority of his rr to ff measurements compounded on top of his stj measurements would be within a 2° range with a rare maximum of 4°. I think most people would agree that that’s a reasonable base to work from and within a range easily rectified by observation of the patient.

Bill Bird

 

:good:

Mr. Bird: Thank you for your educational posting and for its unbiased and civil nature.

I reviewed your website quickly and I wish you were in the States so that I could refer a ton of business to you, especially if you could build shoes that accomodate Centrings.

My perspective is that clinically, biomechanics provides benefit for a large population and there are 6-7 paradigms that claim the same low level evidence proof. They are led by self motivated and self promoting "experts" (witness Kevin, Dananberg, Glaser and Shavelson as some) and they all have some level of following.

My opinion remains that on The Arena, low level evidence and clinical success holds little weight as to the value of a paradigm. Yet even though Root and TSA remain unproven by The Arena standard, on these pages, you would be led to believe that TSA is heavily proven and the others are inferior as witnessed the biased dismissal of all others for TSA.

Using STJ Neutral and STJ Axis in a cliical context, I certainly agree that the error rate is as you say and that it deserves inspection and investigation but no more. It does not eliminate the inspection and investigation of all others as is practiced politically here and itr is not sufficiently proven for me to add its tenets to my EBP.

As I extrapolate Kevin's error rate and add in the fact that Kevin believes that the error rate would be even higher in researchers because intrapractitioner testing drops off from his place atop of his STJ examining pyramid, I am saying that this error rate, in and of itself would produce evidence that would rarely have high level, strong value yet the posture of The Arena is that this evidence exists and we should all become converts.

Mr. Bird, as you say, Kevin's error rate (which by the way is anecdotal and unproven) provides "a reasonable base to work from and within a range easily rectified by observation of the patient" in practice, BUT the standards that the Arena has set include, in addition, the ability to provide strong evidence to justify a biomechanical paradigm using BioNewtonics with other methods of proof being unacceptable.

There is an arrogance of accomplishment in "The International Biomechanics Community" which refers to a body of research and evidence that although unaccomplished and low level as superlative when compared to others.

TSA is unproven and lacks strong, high level evidence.
Root is unproven and lacks striong, high level evidence.
_______ (fill in the blanks) is unproven and lacks strong, high level evidence.

So other than faith and expert opinion, where does The Arena get its masterful place in biomechanics from? Where would it be if you remove Kevin and his work (expert and low level) from its pulpits and shelves?

As I remain a clinician and not a researcher or statistitian, I would appreciate you (or others) inspecting the potential error rate of Kevin's STJ axis or Neutral determination and add that to his rearfoot-forefoot relationship (which would be so much relieved if these two examinations were independent of each other) in selecting 100 subjects to research as to the accuracy that they produce in prescribing rearfoot and forefoot posting or skiving degrees when fabricating custom orthotics for those patients.

My question is, what level evidence would this recearch potentially hold to?

Then lets hold all paradigms to the same standard.

Dr Sha

 

What are Centrings?

I was just about to post this question and thought I would take a look on Google. Found the Foot Helpers website.

Now i realise i'm probably about to go over old ground but would I be correct in saying that "Foot Centring Theory" is covered in 2 paragraphs?

Also DrSha, who is the developer of foot centrings that you follow?

And I'm a bit worried when I see statements like "Nature tried to re-create the engineering and physical wonder of the architectural arch " In Glasgow, we would call this "@rse about t!t"

Are there any published papers research etc on Neoteric Biomechanics or Functional Foot Typing, I would be interested in reading them if you could provide me some links.

Thanks

Robin

 

Just read more on the website and realised that you are Dennis Shavelson and that you are the developer. That answers a few questions.

I consistently read the battles you have on this forum and stop reading when discussions on your theory start as I have not read any research published or papers about it so felt I had no grounds commenting or trying to understand the theory until I had read about it.

Do you have anything published that I can read or is your theory just a mix of principles taken from others work to create something that you use? This sounds like I am being very confrontational but I do not intend fro it to come across in this manner. I don't stick to 1 paradigm, I treat patients based on several factors, the biomechanics bit only being 1 facet of that treatment so I have no axe to grind

Robin

 

Simon,

I guess I was a little surprised by your opinion about the use and benefit of assessing heel bisection and forefoot to rearfoot relationships. I respect your opinion and your contribution to this forum, so I’m attempting to better understand your rationale.

Evaluating structural variation relative to the cardinal body planes between individuals is a common practice throughout the entire human body. As an example of how it pertains to the foot, please consider the following: tibial position (varum or valgum), 1st ray position (normal rom and neutral position, pf 1st met or ray, met primus elevatus), the sagittal plane structure of the foot (pes cavus, average, pes planus, rocker-bottom foot type as an example of extreme deformity ), and radiographic measures such as the angle of 1st ray, calcaneal inclination angle, forefoot angle (ff adductus, rectus, ff abductus), hallux angle (hallux abductus rectus, adductus), etc.

I really don’t see how attempting to assess the plantar plane of the forefoot relative to the heel is all that different, especially since the position of the heel in the frontal plane is such a commonly relied upon indicator of foot position and function. Forefoot to rearfoot assessment alone doesn’t have great significance unless extreme, but used in conjunction with other structural assessments, it can be very helpful. One of the primary benefits is that it allows clinicians to communicate and paint a structural picture of the foot so that they can share information without the patient present. So if I told you that I had a patient with a mild forefoot valgus as opposed one with a plantarflexed 1st ray resulting in a 15 degree everted forefoot angle, it would help us communicate part of the difference between them. Agreed?

 

Jeff, firstly I don't always argue in favour of my own beliefs; I find it helpful to debate from alternate views.

Secondly, here are some thoughts on forefoot to rearfoot relationship:
1) What studies do we have that have demonstrated forefoot to rearfoot relationship as a predictor of pathology?
2) Categorisation is not the same as quantification. We are likely to see less inter-observer error if we only have to choose from 3 categories than if they have to measure and quantify forefoot to rearfoot alignment. We will still encounter problems at the categorical boundaries though.
3) Communication between practitioners will be erroneous if my "forefoot varus" is only a forefoot varus due to my measurement error and is a forefoot valgus when you measure it due to yours, when in reality it is neither.
4) What is the published evidence which links non-weightbearing assessment of forefoot to rearfoot alignment with dynamic function?

That'll do for now.

 

Simon, those are very good questions. I don't believe that I or the research can necessarily answer them for you. With respect to your first question, do you believe that a person’s forefoot to rearfoot relationship can be altered by pathology. I think this is an undisputable yes, given that we see ff to rf relationship changes post CVA and influenced by conditions or diseases such as diabetic neuropathy. Adult acquired flatfoot is often a progressive condition that results in a significant, acquired forefoot supinatus. Are they any studies to prove this? If not, does that mean our clinical observations aren't valid or that they aren't clinically significant? I don't believe so.

If I were to look at your fourth question from a different perspective I would ask, is there any published evidence that shows that pathology can influence ff to rf relationship? Maybe someone else can answer that question. If pathology can influence ff to rf, would it not make sense that ff to rf can influence pathology? I think we are back to the same issue: The absence of evidence is much different than evidence which proves an assumption or theory invalid.

 

Equally the lack of evidence does not prove the theory valid. I've seen flat feet in people with an everted forefoot to rearfoot relationship, and I've seen flat feet in people with an inverted forefoot to rearfoot relationship. What I've not seen is any research which links forefoot to rearfoot relationship with dynamic function nor pathology, that doesn't mean it isn't, but neither does it mean that it is. Because you can get from a to b, doesn't mean you can get from b to a. So, lets say we see a change in forefoot to rearfoot relationship post CVA, that doesn't mean that a change in forefoot to rearfoot relationship results in a CVA, does it? One would think that after all of this time, someone might have tested these relationships? Perhaps they have...

p.S. I'd love to see a study which examines dynamic changes in the forefoot to rearfoot alignment with a 3/4 length foot orthosis.

 

I agree. I know we can change ff to rf relationship in some patients with functional foot orthoses. We could measure ff to rf a number of times with multiple examiners and then put functional orthoses on and then re-measure periodically over a period of six months. I know we could demonstrate a reduction in forefoot supinatus in a group of patients with highly inverted ff to rf conditions and a reduction in ff eversion in a group of patients with significant pf 1st ray conditions. If we could demonstrate a reduction of symptoms and a predictable change in ff to rf relationship, we would have an important piece of research. I think it would be very doable.

 

Jeff, That was the question that Simon asked you. How is forefoot to rearfoot clinically applicable. Does forefoot to rearfoot relationship explain why one foot gets a bunion and another does not. Another example is sinus tarsi syndrome. This condition can be explained by the anatomy where the end of the range of motion of the STJ has been reached. The use of forefoot to rearfoot relationship can be used to explain this, but not as simply as just looking at the range of motion available. So if you have a rearfoot varus and a forefoot valgus will the foot reach it's end of range of motion of the STJ. Because of differences of midfoot stiffness between feet a prediction cannot be made. Forefoot to rearfoot relationship makes discussion of this particular pathology more difficult, not less.

Jeff, I agree when you look at the extremes of feet you can say that one foot has more of a forefoot valgus than another foot. It is a nice qualitative difference. However, if you want to write a prescription for an orthotic, will the measured forefoot to rearfoot relationship be the best predictor of whether or not an orthotic will work. I've seen some feet that obviously have a very large amount of forefoot valgus, yet in stance have the ability to evert their lateral forefoot off of the ground by 1-2 mm. A 7-10 degree intrinsically posted forefoot valgus orthotic for this patient did not work. It tried to evert the foot farther than it could go.

However, when you look at STJ axis position a qualitative assessment of the position of axis can provide you with some idea of how much medial or lateral heel skive to add to a prescription. The more the STJ axis approaches the extremes the more skive you add. I agree that it is not precise. But the paradigm lets you examine qualitatively to make your prescription choices.

Cheers,

Eric

 

http://fas.sagepub.com/content/3/3/112.abstract
http://sapo.incubadora.fapesp.br/portal/artigos/Foot_Postures.pdf

 

So lets see if we have this STJ Axis paradigm defined:

You LOOK at some position and make a qualitative assessment. That then provides you with SOME IDEA of how much skive to prescribe, You admit that IT IS NOT PRECISE and that it provides a qualitative examination.

Please explain why would I want to incorporate a paradigm that is so random, clinician dependent and based on quantification and "some idea" into my EBP?

Dr Sha

 

http://www.udel.edu/PT/davis/Buchanan_2005.pdf

 

Dennis there is a difference between qualitative and random. The reason that you would want to incorporate it is that it works. Don't you just hate writing about the tissue stress paradigm that there is no support for it, except when there is. I'd be willing to bet that a some point there will be a study that shows that medial heel skives work better than non skived devices in the treatment of posterior tibial dysfunction. The paradigm predicts that posterior tibial dysfunction is associated with a medially deviated STJ axis. A medially deviated axis will have a higher pronation moment from ground reaction force. A medial heel skive will reduce the pronation moment from ground reaction force. When this happens there will be less stress on the tendon and it will be more likely to heel. This is not precise, but a logical rationale for the tissue stress paradigm. It does not have to be precise to work. So, your criticism of the paradigm is not valid.

Dennis, You don't even have a paradigm. A centering is another name for an arch support. How does foot typing change the shape of an arch support? Do you make the same arch support for all feet regardless of their foot type? Why would you change the shape of the support for a specific foot type? Dennis, I'm willing to bet that you don't have a logical reason for your paradigm. Here's a chance for you to win an argument. I'm giving you a great big opening.

Are you afraid that your paradigm won't stand up to critical thought on the arena? Why won't you explain the rationale behind your paradigm? There isn't one, is there?

Dennis, this is not bullying. This is academic discussion. You propose an idea. It gets criticized and then you defend it. Dennis, what is your idea?

Eric

 

Simon, Jeff and Eric:

I have been following your discussion on forefoot (FF) to rearfoot (RF) relationship and subtalar joint (STJ) axis location and wanted to make some comments.

As I said in an earlier post, my view is that Mert Root and his colleagues developed a unique foot structure classification system back in the 1960s and 1970s that is probably the best one we currently have available to analyze the intersegmental relationships of the foot and lower extremity. Root and colleagues needed to define a midrange rotational position of the STJ in order to have a reproducible landmark within the STJ range of motion that represented, what they thought, was the best functional or "most normal" rotational position of the STJ. Their resultant STJ "neutral position" is still the most referenced rotational position of the STJ within the medical literature and this, by itself, gives it instant credibility. In addition, the STJ neutral position provides a landmark within the STJ rotational position by which we can reference the terms "pronated STJ" and "supinated STJ". In other words, without a STJ neutral position, the terms "pronated STJ" and "supinated STJ" would have no meaning.

You all have read my complaints over the years about the definition of the STJ neutral position by Root and colleagues (i.e. "neither pronated nor supinated") since this tautological definition does not use any definable anatomical reference frame that is scientifically reproducible. In addition, Eric and I have seen, first hand, in the many students and podiatrists we have trained that what one clinician calls neutral position may be 3 degrees supinated to another clinician or possibly 4 degrees pronated to another clinician. In other words, there is easily a +/- 5 degree variation of STJ neutral position variation within clinicians. This lack of inter-examiner reproducibility makes the STJ neutral position, and all measurements that are based on its determination, quite inaccurate, especially when one clinician is trying to communicate to another clinician the specific structural characteristics of a foot and lower extremity.

However, once the examiner becomes more accomplished at determining STJ neutral position, or becomes "accurate within themselves", I do believe that these methods described by Root and colleagues can allow the individual clinician to be able to very clearly detect even subtle differences in foot structure which may affect the kinetics and kinematics of the human foot. But, will these same measurements proposed by Root and colleagues allow the clinician to talk to a podiatrist from across the country that he/she has never met and discuss with great certainty what exactly a foot is shaped like? No. There is too much inter-examiner error in the determination of STJ neutral and FF to RF relationship to allow this type of meaningful discussion unless the clinicians have previously worked together and compared their results to each other and have not changed their examination methods during the time they have been apart from each other.

I believe that, in order for us to progress meaningfully forward our common goal as a profession, that we must start again from the "ground up", so to speak, and try to agree on some basic facts and then work our way forward from there. For example, I think we could all agree that differences in foot and lower extremity structure can, and will, lead to alterations in the kinetics and kinematics of gait. We probably can also agree then, that it would be meaningful for us, as medical professionals that are devoted to foot and lower extremity biomechanics, to strive toward developing reproducible foot and lower extremity structure classification schemes that would allow us to more faithfully communicate to other clinicians, and to the research community, the specific structural variances that one individual has when compared to other individuals.

Obviously, the 40 year old Root STJ neutral system has its flaws and problems. However, there is no doubt in my mind that foot and lower extremity structure affects foot and lower extremity function. With this in mind, I feel that we, as members of the international podiatric biomechanics profession within our respective communities, need to try to come up with a system that improves on the foot and lower extremity classification scheme that Mert Root and his colleagues worked so hard on, in an attempt to improve the scientific nature of our podiatric profession.

In the many lectures that I attended that were given by this very impressive man, Dr. Root would often state that he didn't think his work and theories would remain in place for more than 10 years since he knew they were imperfect. It is now up to the next generation of podiatrists to take the baton and move us farther along the path toward improved foot and lower extremity structural classification so that we can all better understand how these structural variations affect the kinematics and kinetics of gait and hopefully add to the very impressive accomplishments that Mert Root and his colleagues gave to our profession over 40 years ago.

 

Well said Kevin. I still use the FF to RF relationship as my basis for assessment. My assessment and ultimate orthotic prescription is based on my study of yours and others theories and evidence. My baseline just enables me individually to monitor the effect of subtle changes in prescriptions for each individual based on the confidence of what I have researched and tried of the theories put forward. I go for periods where I maintain a consistent approach then when some pearl of wisdom appears here I begin to incorporate it into my prescriptions based on my FF - RF relationship foundation. If I see positive results in certain individuals I keep it in my tool chest. If not I hang it up in the not useful now cupboard but who know's - may be one day!

Regards

 

I have never been against TSA. I have simply said that foot typing takes you there easier and in a more reproducible manner.

The Flexible rearfoot types have a medially deviated STJ axis and the rest follows.

The stable (ideally) would have no rotational moments and the rigid rearfoot types would have a laterally deviated STJ Axis.

Apply your tissue stress or your medial skive or your varus wedges as you see fit.

Dr Sha

 

Dennis will you please answer Eric's questions? I have a few for you after reading the content of your website after you have satisfactorily answered the questions that Eric has politely asked you several times.

 

Asked and answered on these and other pages.

The biased object of your superficial investigation of my work is ELIMINATION and not amalgamation or inspection. We all realize that no written words on these pages will satisfy the TP's. I await face to face debate.

Kevin can call STJ Neutral and rearfoot to forefoot relationship flawed and of reduced import but simultaneously, we all know that STJ Axis measurement and usefulness is equally (if not more) flawed and lacks quantitative import yet the TP remains mute.

I've read Kevin's bible and his 2001 article is theoretical and nothing in the literature has provided evidence that it is anything more than that since.

Clinicians that I am working with, lecturing to and mentoring have compared their STJ Neutral/ rearfoot to forefoot exam and or STJ Axis exam (I'm not sure how this applies to the forefoot exam) with functional foot typing and have decided to make a change. I represent nothing more than that.

"A failure will not appear until a unit has passed final inspection.” Arthur Block

Dr Sha

Oh and David and TP's, what is the purpose of your questions pertaining to my work?

 

Dennis you want people to accept your work, but at the same time won´t go into details or even answer questions ?????!!!!!

is it because people have not paid for the right to hear you speak on FFT and it´s the money which stopping you ?

I re-read the orginal thread on FFT yesterday and there are still many questions that you did not answer then, if you have answered Eric and others questions maybe you can point me in the direction.

 

David:
In architecture, when two arches are joined by a curved roof, that is called a vault. This means that the med and lat longitudinal arch connected by the area that sits above and along side them form The Vault of the Foot. from Arena pages that I found by doing a simple google search, so can u.

As Simon told me when I asked questions and in his refusal to answer them(paraphrasing)"sometimes you must finds things out for yourself".

You have no idea how many congrats and calls to continue I get when it comes to defend my work on The Arena from silent readers.
To use the oxymoron, the silence is deafening.

Dr Sha

 

Went to here to get a internet reference on the medial and lateral arch of the feet . http://sportsmedicine.about.com/cs/foot_facts/a/foot1.htm

So do you agree with the internet source on the make up of the medial and lateral arches ?

and the Vault is defined as : the area that sits above and along side them form The Vault of the Foot.

so the Vault of the foot is what anatomic structures in the foot , I guess mainly ligaments ?

 

I don;t see the pertinence but to answer, the only subtle changes that I would make is that if the talus did not exist over the calcaneus and act to some extent as part of the keystone of the lateral arch, that arch would not be stable, so I include the talus as part of the lateral arch in an architectural sense. By the same token, without the calcaneus, the medial arch, if it started at the talus, would not be supportive, so it could be included..

No matter what, What is your point?

If the talus is not part of the lateral arch and the calcaneus not part of the medial arch (or is) does this disprove my work?

This leads me back to my previous question which remained unanswered and that is: Since this question doesn't pertain to my work, what is the purpose of this question.

and as to the structures of the vault, I will agree with your definition so that we can move on.

Also, I had an illustration to include but my screen of The Arena is now white instead of brown and I cannot attach, make bold, etc (please address this Craig).

Dr Sha