Prescribing Orthoses: Has Tissue Stress Theory Supplanted Root Theory?

Any chance that we could keep the discussion of growing pains in the thread specifically set up to discuss growing so as to avoid discussing it here?

 

Good point! Sorry.

 

I guess that GPs falls out of the panacea, otherwise known on this blog as tissue stress theory.

 

Be more specific and quit writing in generalities. All of the criticism I've received so far from Euro and Aussie Pods, skirts the issue of the content, instead addressing the process. You even conveniently duck Jeff's question by offering a rather lame "definitional" request. Trust me, Yanks are quite familiar/suspicious with that tactic after Bill Clinton's "what is, is". I also noticed that no one called out Angela Evans when she wrote that patient's lives would be at risk due to practitioners overlooking infection or tumors after reading my paper, even though she didn't discuss either of these differential diagnoses in her papers addressing GPs in 2003 and 2008. Are you holding Yank Pods to a higher standard than yourself or fellow Pods from "your neck of the woods"?

 

Solving the mystery would involve coming up with an explanation. I'm curious as to how you used Root Theory to "explain" Restless leg syndrome. If you think maximum pronation causes restless leg syndrome you would have to come up with an explanation of how maximal pronation of the STJ makes the leg move. Is your logic maximal pronation is abnormal so this abnormality caused restless leg syndrome? How many patients with restless leg syndrome have vertical heels. They should be normal. You would also have to explain why some people who are maximally pronated in stance don't get restless leg syndrome. You may have found a correlation, but have not solved the mystery.

I wouldn't expect tissue stress theory to solve restless leg syndrome. Restless leg syndrome, is neurologic or physiologic and not mechanical.

Use the tools as they are intended to be used.

Eric

 

Here is what Craig said regarding "vested interest" in his landmark paper from 17 years ago: The past, present and future of podiatric biomechanics:

"There will always be attempts to integrate paradigms with each other as a means of saving a given paradigm. This is generally done by those who are still "wearing the lens" of the current paradigm and could be seen as an attempt to co-opt the competing paradigm. For example, it has been alleged that the biopsychosocial model is nothing more than an attempted take over of the psychosocial model by the biomedical model. The biomedical model has the support of powerful financial interests, namely, the pharmaceutical industry. Similarly, the current podiatric biomechanics paradigm is supported by the commercial orthotics industry, which will resist any paradigm shift that it does not regard as in it's own interest."

Interesting how this idea of attempted co-option has so obviously been seen within this thread with attempts to suggest that Root was also taking a "tissue stress" approach. Prophetic, Craig.:drinks

 

In 17 years, please reread my new quote:
There will always be attempts to segregate paradigms with each other as a means of trying to create a new paradigm or paradigm shift. This is generally done by those who are attempting to create "a new lens" of the new paradigm and could be seen as an attempt to opt-out the competing paradigm.

Jeff

 

Is that the "clinking, clanking sound" I can hear? https://www.youtube.com/watch?v=rkRIbUT6u7Q

You are welcome to your point of view Jeff. As I said, twenty years of such discussions has taught me that I won't change your mind with my postings on social media. For that matter, neither will anyone elses posts. But the fact remains, your dad's model has been found wanting on too many occassions for me, and it seems for the rest of the world outside of the USA to take it seriously anymore. The majority of critical thinkers in the field have moved on. Craig also discussed the importance of critical thinking being employed in podiatry schools 17 years ago, I wonder how this is reflected in the US curriculum today? It seems from the writings here that some US podiatrists still clearly lack a basic understanding of research methods which doesn't bode well if the aim is to provide practitioners who are able to critically evaluate research publications.

Out of interest, are you still President of the Prescription Foot Orthotic Laboratory Association?

 

Eric,

Is a vertical heel in which the STJ is maximally pronated when the heel is vertical a "normal" foot according to Root theory? No. That is why you need to use things like Root's heel bisection technique and STJ ROM examination in order to know where the STJ is within its ROM. Does tissue stress theory theory tell you anything about the ROM of any joint? No. This is why tissue stress theory can't stand alone as a model of foot function and treatment.

Jeff

 

Merton Root was a big proponent of STJ being the "center" of many foot pathologies...and I now agree. Perhaps if you and I had paid more attention to Dr. Root, you would've solved this mystery yourself, or it wouldn't have taken me so long. Eric....ALL pain is essentially "neurologic", at least the transmission/perception portion. It appears you never read the article....did you? If you had, you would've read about 'Referred Pain'. If you had, you would've made the connection between STJ subluxation and transient synovitis/capsulitis. If you had, you would've known that many of Root's precepts are included in the text and videos which explain the maladies. Yes, I did happen to use non-Rootian methods to treat, but all that does is help explain his work in progress. You tissue stress guys berate those that haven't read your articles, and/or kept up with the literature. May I suggest the same to you?

 

According to Root theory a vertical heel is normal. No rationale is given for when to choose one criteria over the other. By the way, why should the "normal" foot stand in neutral position? Is it because that is where the heel is supposed to be vertical?

In tissue stress we identify the injured structure. If there is pain on range of motion of the joint then all theorists would conclude the damaged structure is the joint. Say we have a narrowed joint space on x-ray. Should we put that joint into neutral position to address its pathology?

A test that I commonly use is the maximum eversion height test. It assesses range of motion of joints. I feel this measurement is a better predictor of whether there is eversion range of motion available in stance than the measurements found in vol. 1.
Measurement of range of motion is not precluded when using the tissue stress approach.

Eric

 

Of course not, but Jeff probably thinks his dad invented range of motion assessment

I could have sworn a couple of pages back we were being told by the Root advocates to view each criteria in it's own right, that we didn't need to observe all of them in concert to have a "normal" foot...

 

Matt, I'll admit that I didn't read the whole article. I'll go back and read it, if you can explain how "referred pain" makes the leg move. I'll admit that some pain is referred. You can get pain in the foot with nerve damage in some other location. However, referred pain should not be used as a diagnostic crutch. You should be able to reproduce the pain when you irritate the involved nerve. Yes, there is synovitis with maximal prnonation of the STJ. That usually causes localized pain. Matt, why do you think a localized synovitis will cause referred pain? Which nerve do you think is involved?Could you expand a little further on your referred pain theory?

You could also address one of the other points that I made. How come all people that stand maximally pronated people don't get restless leg syndrome.

I remember standing in a hallway with John Weed describing STJ subluxation in gait. If you look at the anatomy of the STJ, it cannot sublux in the direction of pronation. What people see when they talk about STJ subluxation is actually mid tarsal joint movement.

Eric

 

Eric,

Root also wrote that in the normal (ideal) foot the ratio of supination to pronation is 2 to 1. Therefore in the ideal foot, when the heel is vertical, the STJ would be in the neutral position and there would be twice as much inversion as eversion available from this vertical heel position.

We are not treating ideal feet, we are treating real feet. The ideal is just a theoretical baseline for optimum stability as proposed by Root. I think we can agree that ideal is a debatable. I don't get hung up on ideal but rather look at individual function, position, ROM, etc. as compared to ideal. If someone is maximally pronated in resting stance, they may or may not have related pathological. However, if someone is maximally pronated in resting stance and they appear to have symptoms related to insufficient pronation ROM, then it is significant and I would try to address it in my orthotic prescription.

Jeff

 

You can judge and evaluate each criteria individually and consider them in their totality.

 

A typical Spooner comment. By the way, what was your father's occupation Simon? Professionalism seems to be new to you so I have to assume he wasn't a professional man.

 

But Steindler in 1955 had already written "The range of the subastragalar joint has been given variously as from 20-45 degrees (Fick), the pronatory range exceeding the supinatory at a ratio of 3:2". I guess any books which don't provide hard data, nor theoretically coherent concepts are at best, guessing. Luckilly, what we now understand is that variation in the axial position of the subtalar joint exists within the "normal foot" and that planal dominance as nicely explained by Green, tells us that variation in the axial positon will result in variation in the range of motion at the subtalar joint in the frontal plane. One of the first issues I had with your father's ideas Jeff, was the use of the 2:1 ratio to calculate neutral position- it is a none science that does not take into consideration the normal variation among humans nor stand up to scientific scrutiny. Perhaps though you could explain why a 2:1 ratio of supination to pronation should be biomechanically ideal at this joint?

 

Nice. My father was a printer. He taught me to read critically and to engage in critical thinking. Me? I'm a podiatrist that holds a PhD, which the last time I looked a PhD is something like the highest academic award that can be bestowed upon an individual. My father was very proud of this achievement, as he was of the achievements of all of his children. Aren't you a fireman by training?

I feel sorry for you Jeff, you have chosen to defend your fathers honour in the face of science. It won't be easy for you.

 

John Weed also wrote: that neutral could be palpated at maximum congruency and neutral occurs when the curvature above and below the ankle was similar would also be neutral position. Why are any of these ideal?

Following your statement to its logical conclusion we don't need the criteria for normalcy. The difference between tissue stress and neutral position theory is that in Neutral position theory you push the foot toward ideal and in tissue stress you push the foot away from increased stress on the structure that is damaged.

When you have a laterally unstable foot that rests on the pronated side of neutral, neutral theory would have attempt to supinate that foot and tissue stress would have you pronate that foot. There is a difference between tissue stress and neutral position theory.

Eric

 

Did you ask that question before? I don't think the 2 to 1 ratio has a lot of clinical value. In other words, in the ideal foot that Root described, there is a mathematical neutral position. In the actual patient foot we can place the STJ in the neutral position and measure the range of calcaneal inversion and eversion. It is not necessarily a 2 to 1 relationship. On average, we see rearfoot varus (an inverted neutral position) and the foot on average rests with the heel in a pronated position at the STJ. However, the heel could be inverted, vertical or evented when the STJ is in this pronated position.

I think there is important clinical information gained when looking at the open chain relationship of the ROM of the calcaneus and comparing it to the distal 1/3 of the leg and to the floor.

Jeff

Jeff

 

But that wasn't really the question, to reiterate the question was: why should a 2:1 ratio of supination to pronation at the subtalar joint be biomechanically ideal?

Here's another question Jeff: if the calcaneus is inverted, can the subtalar joint be pronated? I guess it depends on your point of reference. But since the motion of supination is defined as inversion, plantarflexion and adduction and pronation as eversion, dorsiflexion and abduction, then the positional references of supinated should be inverted, plantarflexed and adducted and pronated should be everted, dorsiflexed and abducted. Given this, neutral position should be defined as when the subtalar joint is neither pronated nor supinated. Now, if we take a vertical line representing the frontal plane as our determinant of inversion versus eversion and pass this through the subtalar joint and if we take the calcaneus as our reference of subtalar joint position to this, then if the calcaneus is inverted- the subtalar joint must be also be supinated. I beleive this is the international standard for measuring joint position and motion- that is in terms of position relative to the anatomical planes. I have a book on international standards in biometrics- I've got to go into work tomorrow, so I'll double check with it.

 

They are not ideal and no one I know of said they were ideal. Weed and Root used these as clinical techniques to identify the neutral position. Root himself didn't use TNJ palpation to identify neutral. He did observe and note that when the STJ was in the neutral position, and in the absence of obesity and edema, the curves above and below the lateral mallelous were common in appearance and he noted how the relationship of these curves changed with supination or pronation at the STJ.

In Root Theory, you don't always push the foot toward ideal position. I have said this repeatedly! For example in strict Root theory, using rearfoot varus as an example, you would take a neutral position cast and correct the heel to vertical, which is actually a pronated position of the STJ. Why did Root originally advocate this? Because when he was practicing he didn't have success attempting to position (control is the common term used for this) the heel in an inverted position with an orthosis. Only after he retired, and while he was a consultant for Root Lab, did he begin to recommend inverting the cast to increase supination moments (inversion force) with an orthosis due to increased heel cup heights and other changes in how orthoses were being prescribed.

Jeff

 

Simon,

I don't know why a 2 to 1 relationship would be considered ideal. I think it was a theory based on observation of STJ ROM measurements and not based on ideal from a mechanical perspective.

As to your second question, rearfoot varus is an inverted neutral position of the STJ. Therefore, if you can have an inverted neutral STJ position, then you must be able to have an inverted pronated STJ position since motion in the direction of pronation beginning at the STJ neutral position would being with the heel in an inverted position.

Jeff

 

Yeah, I understand that rationale, i.e. although it is inverted it is relatively more pronated than the neutral position. I just don't think you should be measuring joint position from the "neutral position", rather it should be from the reference planes. We don't talk about the knee joint being extended from its "neutral position" do we? Moreover, if the neutral position is when it is neither pronated nor supinated, by definition, the neutral position can't be inverted. Like I said, I got a book on international standards for measurements in biometrics- I'll check with it tomorrow see what it says. I would say that the joint you describe above is supinated but at it's end of range of pronation.

 

Try reading the article first. Focus on Page 83: "Where is the Proof". Considering the fact that your chapter in Albert's book is 55+ pages long, reading my 6 page condensation of the original manuscript should not be too much to ask. I mean, seriously.

 

BTW, spotted this tonight. http://www.vasylimedical.com/products/product_tom_mcpoil.html

I know we shouldn't speak ill of the dead, but apparently Vasyli think that Tom Mcpoil introduced the load-deformation curve! OKKKKKK....??

Suggestions of the marketing men not really understanding the concept- lets just hope the tissue exhibiting excessive stress is not the medial knee cartilage in someone with medial compartment O/A of the knee, or the lateral ankle ligaments in someone with chronic lateral ankle instability.

Suggestions of jumping on the band-wagon? "If you are in marketing, kill yourself"- Hicks.

 

Here you go: according to this text: in Vancouver BC 1962, the methods descibed within were unanimously accepted by representatives of all English speaking countries, including Australia, Canada, Great Britain, New Zealand, South Africa and the United States for measurement of joint range of motion. Here are some pictures from the text showing these internationally accepted methods for measuring rearfoot range of motion.

Anyway, since my father's social class is now being thrown at me as criticism of my opinions here within this thread, and since the Root problem is really only applicable to the United States, I'll opt out of this discussion. I only hope that the curriculum in US podiatry schools join the modern age soon such that those emerging from such schools have a sound grounding in modern biomechanics and research theory and are able to critically engage with, design and implement quality research rather than just dogmatically adhere to the same old, same old. Yet I doubt it, while those with vested interest in Root theory still rule the roost. You seem to like your dynasties in the US, with your John Robert Seniors and your John Robert Juniors. Anyway, nothing's going to change while you've got the same old family making the decisions for the foot orthotics industry's associated body there. Good luck with that. Let's elect another Bush because the last two had a tremedously positive effect on global stabiity and world peace...

 

Don't worry, Simon, we have been teaching Tissue Stress Theory at the California School of Podiatric Medicine for the past five years. I think the other schools in the US are also starting to teach it. I'll make sure of it.

 

Make sure they have sound grounding in research methods 101 too. It's about empowering them to critically review the literature and come to their own decisions. When I started teaching tissue stress theory in the UK podiatry schools, 17 years ago, the first thing we did is get the students to critically evaluate the contemporary theories as an assessed piece of work. Many of these students have since come back to me and thanked me for the grounding provided.

 

I was teaching STJ axis location and rotational equilibrium theory in the UK (Cheltenham) back 19 years ago, in 1996, at the Langer Smorgasbord Seminar. Ron Valmassy was also lecturing with me. We have come a long way since that time.

Since I'm only there at the California School of Podiatric Medicine a few times a year, we try to focus on Tissue Stress Theory, STJ axis location, SALRE theory, midtarsal joint biomechanics and foot orthosis biomechanics in my lectures. Don't have the time for much else in the short time I'm there.

Also, I don't think you need to worry about the US schools of podiatric medicine too much, Simon, since the recent graduates of the schools that I meet and teach have no problems with the concepts of Tissue Stress. I believe that it will just be a matter of time before Tissue Stress Theory is being taught at all the schools in the US.

In fact, I'm lecturing on Tissue Stress Theory to the students at the New York College of Podiatric Medicine this coming November for the first time. In addition, I just introduced the concepts of Tissue Stress Theory at the Colorado State Podiatry Meeting and in San Diego at the Podiatry Institute Surgical Seminar in 2014. Hopefully, the chapter that Eric and I wrote on Tissue Stress Theory will become required reading at all the schools within the near future (Fuller EA, Kirby KA: Subtalar joint equilibrium and tissue stress approach to biomechanical therapy of the foot and lower extremity. In Albert SF, Curran SA (eds): Biomechanics of the Lower Extremity: Theory and Practice, Volume 1. Bipedmed, LLC, Denver, 2013, pp. 205-264).

 

Who's teaching tissue stress at CCPM?

 

CCPM hasn't existed as an entity now for 13 years. I incorporate Tissue Stress Theory into the classes I teach to the second and third year podiatry students at the California School of Podiatric Medicine at Samuel Merritt College in Oakland. Drs. Cherri Choate, Tim Dutra and Joe Hewitson, all previous students of mine, also incorporate Tissue Stress Theory into their biomechanics classes at CSPM.

 

CCPM or CSPM...you knew what I meant. But thanks for reminding me that accuracy is always important. Therefore, since we're being sticklers for accuracy... Dutra was in my class and learned Biomechanics from Valmassy, Scherer and Weed...you weren't teaching. And when I met with Choate, Dutra and Andrew Smith, a couple of years ago, none of them mentioned tissue stress theory when I showed them my work and discussed my research projects...not one word. So I'm somewhat confused about your credentials.

 

I see Drs. Choate and Dutra a couple of times a year when I teach at CSPM and they told me they were teaching some Tissue Stress concepts in their classes also. Tim Dutra was in the CCPM Class of 1985, when I was a Biomechanics Fellow and he was one of my students during his biomechanics rotation.

 

Then if I accept what you wrote above as being true, with Dutra and Choate teaching "some" tissue stress theory, you've answered your own question posed as this threads header....no, TST has not Supplanted Root Theory...and is being utilized to augment Root Theory. There's a difference between paradigm shifts and adjunct information.

BTW...it's refreshing to see Simon post pics of biomechanical evals that use goniometers, reference lines and degrees of motion determinations. It is a beginning.

 

Matt,

Excellent point! And who are the tissue stress leaders at any of the podiatry schools? I'm not saying that there are not problems with "Root Theory". I'm saying that Tissue Stress Theory (TST) uses a blend of Root and other theories, diagnostic techniques, clinical techniques and orthotic prescription protocols.

Some have criticized Root Theory as being too rigid and absolute and they argue that Root's orthotic prescription protocol is too narrow or simplistic. However, TST is too vague, has no standards, no orthotic prescription protocol and as a result, isn't practical to teach since every teacher will be teaching something different based on their own interpretation of the simplistic basis of TST that, according to Kirby's article are to

In Kevin's article he wrote:

What is an appropriate biomechanical examination according to TST? We see here on the PA that Kevin, Eric and Simon, three of the chief leaders in TST have significantly different opinions about biomechanical examination methodology and what biomechanical information might be necessary to treat the patient. So what standards exist in TST? How can STS be taught with any expectation of success unless there are some basic tenets to go by? I agree that there are elements of TST that are very beneficial such as attempting to better understand the nature of pathological forces and designing the orthotic to reduce pathological forces. Who would argue against that? Not me. The reality of it is, TST is being taught at some of the podiatry schools and in conjunction with other theories, not as a replacement for them.

Jeff

 

Jeff-while I have no doubt that your Dad would object to some of my techniques, I'm pretty certain he would see value in the exploration process that I have taken. For instance, I'm not sure he would agree with my varus extensions to the end of the toes in treating forefoot basis/supinatus, but until someone can come up with a better solution, I'm stuck treating patients successfully using that method. Given that Merton didn't have polypropylene to use and/or computer software to "read" negative casts, I can understand his reticence to hold the calcaneus in a more inverted position while attempting to treat rear foot varus deformities. My point being is that as practitioners and researchers, (if I maybe be so bold to include myself in the latter category), we should be attempting to expand, define and further your father's work, not necessarily trying to REdefine it.

 

Your statement needs the following caveat: In the US.

 

We were talking about the U.S. schools.

 

Do podiatry schools outside the U.S. teach:
1. The concept of the neutral position of the STJ?
2. That forefoot varus and forefoot valgus are determined with the STJ in the neutral position and with the MTJ fully pronated?
3. The concept of rearfoot varus and rearfoot valgus and how these conditions are determined clinically?
4. The neutral position, suspension casting technique?
5. How to prescribe and manufacture a Root type functional orthosis?

Let's again review the definition of supplant:

sup-plant [suh-plant, -plahnt]
verb (used with object)
1. to take the place of (another), as through force, scheming, strategy, or the like.
2. to replace (one thing) by something else.

How have the podiatry schools outside of the U.S. supplanted these basic elements of "Root Theory"?

Jeff