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Forefoot Valgus

Discussion in 'Biomechanics, Sports and Foot orthoses' started by jrsenatore, Mar 4, 2012.

  1. jrsenatore

    jrsenatore Member

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    My question deals with a rigid forefoot valgus who is a runner. My thoughts were to order an orthoses with a high arch fill (to flatten) compared to a tight fill. I also would like to correct as much of the valgus deformity as possible and correct it only with intrinsic posting. I also use a forefoot valgus wedge under the met heads. The orthotic lab I use suggested only correcting up to 8 degrees of the valgus and using a tight arch fill on the positive cast otherwise there would be a gap under the arch.
    My question is with the STJ axis, is there a lateral shift or deviation of the axis in this type of foot? If so, I would think that an orthoses with a lower arch and lateral forefoot wedging would be better tolerated.

    John Senatore
  2. John:

    Hope all is well.

    I would rely less on what the forefoot to rearfoot relationship is and more on what the runner's symptoms and pathology are before I decided on whether I made a custom foot orthosis for a runner with a foot like this and how, if they needed an orthosis, I woulddesign their orthosis.

    Typically, a foot with what Root and Weed called a "rigid forefoot valgus" would have a laterally deviated STJ axis that could very well have symptoms due to excessive STJ supination moments, such as lateral ankle instability or peroneal tendinopathy. In these feet, I would tend to use more of a valgus wedge/lateral heel skive. However, I have also seen runners with feet with what Root and Weed would call a "rigid forefoot valgus" suffer from medial tibial stress syndrome where I needed to do a very tight fitting medial arch to alleviate their medial tibial pain.

    Many of us now have moved toward designing our orthoses based on Tissue Stress Theory, were we treat the injured structures, versus the older STJ Neutral Theory , where we treated "foot deformities". We were trained in podiatric biomechanics at CCPM many years ago and there has been a revolution in treatment in many countries in podiatric biomechanics since the early 1980s. I have noted that the treatment results with Tissue Stress Theory are much more predictable and also makes much more sense than trying to treat "foot deformities" with Root et al's STJ Neutral Theory.

    Hope this helps.:drinks
  3. efuller

    efuller MVP

    Hi John,
    To add to Kevin's excellent post. To point out more explicitly; when Kevin said "typically" referring to a rigid high arched foot type, I believe he meant that the majority of the time you will see a laterally positioned STJ axis, but some of the time you will see a high arched foot with a medially positioned axis. It is more rare, but you should not treat averages, you should treat the complaints that person presents with. Conversely, there are some rare low arched foot with laterally positioned axes.

    I've heard labs say that an intrinsic valgus post of more than 8-10 degrees will take up too much room in the shoe. I don't agree with notion that a gap under the lateral arch is a problem. The orthotic material is rigid enough to support the medial arch, so there should be no problem with supporting the lateral arch with a gap under the lateral aspect of the orthosis. In fact, that is how the valgus "correction" is placed in the orthotic. When you place a solid wedge under the lateral forefoot, when the foot is sitting on the wedge it is higher off of the ground than if there was no wedge. There is no reason the wedge needs to be solid to lift the lateral forefoot off of he ground. However, it does need to be rigid. When an orthotic is made with an intrinsic forefoot valgus post the distal lateral edge of the orthosis should curl down ward so that the lateral part of the orthotic under the 5th met shaft is now higher off of the ground than when there was no orthotic.

    One other problem with treating the forefoot to rearfoot relationship is that you don't necessarily no where that relationship is to the ground. If you combined a large amount of forefoot valgus with a rearfoot varus, you may not have enough eversion available in the STJ and MTJ to accommodate the wedge the size of the number of degrees that you measured in the forefoot to rearfoot relationship. In other words your orthotic may be trying to evert the foot farther than it has range of motion to evert. I've made this mistake, and you will either see pain on the plantar lateral foot or sinus tarsi pain when you make the mistake of trying to evert the foot farther than it can go.

    I've developed a measurement that I call maximum eversion height. Have the patient stand and ask them to evert and look at the height of the lateral forefoot off of the ground. Don't make the orthotic's intrinsic forefoot valgus post higher than this height. I wrote more on this in another thread with the title maximum eversion height.

  4. jrsenatore

    jrsenatore Member

    Kevin and Eric
    Thanks for the quick response. I actually have not used the term “rigid forefoot valgus since the good old CCPM days but Dr. Chris Smith is the guru at Northwest Podiatric lab that has been helping me and gave me a little refresher of 1980’s biomechanics.
    I agree with you that treating the patient’s symptoms are important. This particular patient (runner) has a split in his Peroneal brevis tendon (just found on the MRI). He will need surgery but he is determined to return to competitive running. The lateral stress on the peroneals can be reduced with an orthoses and I think that measuring the maximum eversion height of the lateral foot makes sense. Do you recommend a tight fit under the medial arch or should the arch height of the orthotic be lowered?
    Thanks again Kev. for the reminder that I am an old fart!

  5. efuller

    efuller MVP

    Hi John,

    If you are still in contact with Chris say hi to him for me.

    Regarding arch height, It depends on the position of the STJ axis. I would tend to lower it in a foot with a more lateral axis and keep it relatively high in a medial axis. Although my relatively high is probably lower than others realtively high. It shouldn't be so high that it hurts. j

    With a split in the peroneals, and if that is where the pain is, then you could add a lateral heel skive as well. Make the ground pronate the foot so that the peroneals don't have to. I wonder what Chris would say about that. Chris was one of my favorite professors when I was a student.

  6. John:

    For a split peroneal tendon, you can try an orthosis with a lateral heel skive and valgus forefoot extension and a slightly lower than normal medial longitudinal arch height to increase the center of pressure on the plantar foot more laterally and, hopefully, decrease the tension stress on the peroneal tendon. However, in all likelihood, the patient will continue to have peroneal tendon pain while running, no matter what orthosis is made for him, until the peroneal tendon split is surgically repaired.

    You weren't always an old fart, Senatore.;):drinks
  7. markjohconley

    markjohconley Well-Known Member

    Goodaye Eric, I have been using this 'test' for a while since i read it on one of your posts a while ago.
    My query is would some patients not have the neuro-muscular ability to evert their forefeet though it would be possible otherwise? thanks, mark
  8. efuller

    efuller MVP

    It's rare that a patient walks into your office with peroneals so weak that they cannot evert in stance. I tried developing a platform with a hinge in it and then built a pulley system that could lift the hinge with the foot on it. I tried various weights and found that the eversion height, caused by the hinge movement, was still dependent upon the subject wanting to maintain their standing position. A certain amount of weight would cause the person to allow the top of the tibial to move medially. The weight that moved the tibia was dependent upon the weight of the subject and it got to be too hard to try and consistently quantify the amount of eversion with the platform and hinge. The problem is that each brain attached to each foot works differently and different people will "fight" the tendency of the tibial moving differently.

    So, that is a different method by which you could measure maximum eversion height that would not require the patient to use their peroneal muscles. A few patients will just not understand the instructions. One thing that John Weed taugt was to attempt to place your fingers under the lateral foreoot when the subject is standing. If the subject has very little eversion available. your fingers will hurt. If they do have range of motion available your fingers may not hurt, in most cases. The rigid forefoot valgus foot may hurt your fingers and also have a large eversion height. I'm too tired to explain that now. So, there are many ways to get this information.

    Last edited: Mar 6, 2012
  9. Jeff Root

    Jeff Root Well-Known Member

    I would recommend that you check to see if it is necessary accommodate the plantar fascia for this patient. Medial arch discomfort is sometimes (perhaps often) caused not by the height of the medial arch of the orthosis, but rather by orthotic pressure against the plantarly prominent aspect of the plantar fascia. You can probably use a higher, more conforming medial arch as long as it doesn’t irritate the fascia. If the fascia is plantarly prominent and you don’t accommodate it in the orthotic shell, you are more likely to get medial arch discomfort from your orthosis.

    To evaluate the fascia, place the foot in the neutral stj position and maximally pronate the MTJ (just for consistency purposes between patients) and dorsiflex the hallux to resistance. Using the opposite hand, simultaneously palpate the fascia for firmness and observe its relative height or plantar prominence. If there is bowstrining of the fascia causing it to be plantarly prominent, and especially if it is feels firm when you palpate it, then I would recommend you mark the margins with a pen so it transfers to your plaster cast and ask the lab to accommodate it (typically 2 to 5 millimeters in depth).

    In this foot type (cavus foot with ff valgus and or a plantarflexed 1st ray) I believe the intrinsic valgus correction is the key to success and a valgus forefoot extension is a good idea. However, if you don’t have enough orthotic reaction force in the medial arch, then the patient might perceive the valgus support as being excessive due to the relative increase in pressure on the lateral aspect of the forefoot.

    Speaking of Root biomechanics, on a sad note David Francis, DPM who took over my father’s practice in the 1970’s passed away yesterday after losing his battle with cancer. Dave was an extremely gifted clinician and it is a shame he never went into teaching as he was probably one if not the best practitioners of Root type biomechanics that I know. Dave was a wonderful person and my thoughts and prayers are with him and his family.

    Jeff Root
  10. drsha

    drsha Banned

    I would like to change Dr Kirby's word "deformities" to the word "structure" so that architectural terminology and principles apply.

    The word deformity suggests that our feet change from their natal foot type but in the case of The Rigid Forefoot Foot Types as in this case, they do not "deform" much during ones lifetime.

    Kevin relies "less on the rearfoot to forefoot relationship" and further states that this "makes more sense than trying to treat with Root et al's STJ Neutral Theory".

    In fact, I couldn't agree more but I have upgraded Dr Root's forefoot examination and not abandoned it.

    We need testing that will allow diagnosis and understanding of the mechanics of the rearfoot and the forefoot independently, not interrelated as in Rootian Theory.

    Dr Root's forefoot exam needs upgrading but his tenets that the structure of the foot should be a focus in biomechanical care and that the forefoot merits importance remains a core of FLEB.

    His forefoot test is an open chain test with no application of additional moments and forces in open chain upon the forefoot that give insight to the impact of grf and other closed chain forces and moments when feet are weighted.

    In Serm-Perm testing of the forefoot, the application of a plantarflectory force upon the 1st met when SERM testing, imitates the maximum force that a first ray will drive when weighted as in this case of the rigid forefoot type.

    By itself, like Root's forefoot exam, it tells little because it does not predict where the ray moves to or how it changes function when weighted in midstance.

    The rigid, stable and flexible forefoot FFT's all test plantarflexed for their SERM reading (valgus) but one stays plantarflexed (valgus), one moves to online with the 5th ray ("neutral") and one moves into a dorsiflexed position (varus) when examined in PERM.
    Rootian forefoot examination calls all three types some form of valgus when in fact, calling them all "valgus deformities" reduces a practitioners ability to treat forefoot pathology where it exists, on the sagittal plane and transverse plane of the midfoot and forefoot (Dananberg).

    Functional Foot Typing, by adding forefoot PERM testing, uses a dorsiflectory force upon the first ray starting from SERM position. This separates these three types into rigid, stable and flexible which suggests more focused forefoot treatment without consideration of The STJ Axis.

    In FF PERM, the rigid forefoot types remain plantarflexed, the stable types dorsiflex to online with the fifth met head and the flexible forefoot types become dorsiflexed reflecting how these rays compensate when weighted in midstance.
    One functional foot type reduces 1st ray stiffness, one has little effect and the third increases 1st ray stiffness that needs to be addressed biomechanically.

    Foot Typing applies from birth to death and before, during or after symptoms or injury as TSers are waiting for.

    I submit that SERM-PERM testing of the forefoot is an advance of Dr Roots method of testing but does not reduce his amazing insight as to the importance of structure when it comes to diagnosing and treating feet.

    Merton and I agree that external forces and moments are a critical part of biomechanical care (ORF's and Muscle Engine Balancing and Training) as do TSers like Dr's Kirby and Fuller. However, foot typers believe that the position of the foot is the foundation upon which external forces and moments are applied and as a starting biomechanics platform may be more important than any ORF or Muscle Engine Training in the long run for rendering primary care.

    Architecture lives in Dr Root's (and my) corner and has become vestigial or nonexistent in Kevin's.

    I have been told that Dr. Root believed that his work would be upgraded, massaged and advanced in the future to a better and more universally applicable place. I am making his prediction ring true, Kevin is not.

    Finally, when treating the rigid forefoot foot types, I aim to reduce the strength and function of P. longus because if the 1st ray can be made a poorer locking system, the stiffness of the ray reduces and over time, Wolf's and Davis' Laws locks the ray in a more dorsiflexed position "correcting" the structure of that foot (I have heard Jeff Root discuss this "corrective" phenomenon of the rigid forefoot foot type as part of his Dad's research).

    Finally, if what Kevin believes is true, and subtalar joint neutral biomechanics should be replaced with TS, why would STJ Neutral casting be the one and only casting technique for so many and the main casting technique for the rest of us without the need for change or the interjection of a new, more organized set of casting rules, foot type-specific?

  11. efuller

    efuller MVP

    Dennis, you are not characterizing tissue stress correctly. The reality is that most patients present to us with complaints. You can apply tissue stress without a complaint, but that's not what happens the vast majority of the time. For example, if someone came to me, and was asymptomatic, but had a medially deviated STJ axis, I would have no problem giving them a varus heel wedge device.

    It's a step backwards, because SERM-PERM ignores the relationship of the foot to the ground. The "effect" of tibial varum changes how the foot functions.

    The position of the foot on the ground is important for analyzing the stresses acting on anatomical structures. SERM-PERM may have some relationships to the foot as it stands on the ground. I'd rather look at the foot on the ground, if I was going to try and understand how ground reaction force affected it.

    Architecture is the wrong body of knowledge to be used in biomechanics. Yes, structure is important, but that can be assessed without using the terminology of architecture. Engineering is the correct body of knowledge if you want to understand the stress on anatomical structures. So, yes tissue stress does not use architecture, but it does look at the structure on the ground.

    Another inaccurate characterization of tissue stress. You can use tissue stress with any casting technique, type of shoe, type of brace, or even a wedge.

    Dennis, you obviously derive great joy from typing feet. You still haven't told us what you do differently with that information. mental masturbation


  12. Jeff Root

    Jeff Root Well-Known Member

    I'd rather look at the foot both weightbearing and non-weightbearing. Why unnecessarily limit yourself to one method or the other? Root advocated a system of examination that included, at a minimum:
    1. A comprehensive medical history including but not limited to the history of the patient’s chief complaint(s)​
    2. A comprehensive biomechanical examination that included:​
    a. A non-weightbearing morphological examination the foot and leg to identify the structural relationship and features of the lower extremity (and in some instances might warrant a more extensive examination of the pelvis, back, neck and head)
    b. A non-weightbearing morphological examination the foot and leg to examine the range of motion, quality of motion and axial relationship of the major joints of the foot and leg (stj, mtj, ankle joint, 1st ray, 5th ray, knee, hip, etc.)
    c. Muscle testing
    d. A static stance evaluation of the osseous relationship of the foot and leg
    e. A gait analysis to evaluate the function of the neuromuscular and osseous systems combined​
    3. Radiographic evaluation (at the time it was part of the stand patient biomechanical evaluation) to identify any osseous anomalies
    4. Any laboratory or outside testing or referral, as needed
    Root’s system was designed to identify any correlation between the patient’s symptoms and the patient’s structural/functional condition or could be used in reverse to evaluate the patient’s structural/functional condition in an effort to identify current or to attempt to predict any potential future pathology. The osseous and neuromuscular systems are dependent systems and while we attempt to separate them for purposes of study and examination, they do not function independently during human locomotion.

    I’m confused. Why place any greater importance or significance on tissue over bone? It doesn’t make sense to suggest that non-weightbearing and weightbearing examination of the patient are not both extremely valuable. I think there is too much bias displayed on the Podiatry Arena in an effort to advance one’s particular “theory” when in fact, the practice of biomechanics and foot orthotic therapy reflects a much different reality.

    Just my opinion,
    Jeff Root
  13. efuller

    efuller MVP

  14. Jeff:

    When I was in podiatry school at the California College of Podiatric Medicine, all of the 106 podiatry students in our class were not taught a multitude of biomechanics theories. We were only taught one theory of biomechanics and this was your father's and his coworkers' Subtalar Joint Neutral Theory.

    Since this theory was taught to us as "The Way" and no other theories of biomechanics evaluation and treatment were taught to us as podiatry students, then, by definition, Subtalar Joint Neutral Theory was viewed by us students as dogma.

    Here on Podiatry Arena, we discuss all theories, not just "The" Subtalar Joint Neutral Theory that we we were taught while I was a podiatry student at CCPM. We consider all alternative theories here on Podiatry Arena. We think about them, review each of the main points of the theory and discuss the scientific evidence both pro and con for each theory. (What I would have given for a Podiatry Arena when I was a student!!)

    At CCPM, as podiatry students, it was drilled into us that "The One Theory" explained how the foot worked. We were taught that nearly all mechanical problems of the foot and lower extremity should be treated by Rohadur orthoses with 4 degree/4 degree rearfoot posts, with vertical cast balancing position, no forefoot extensions, and should be casted with a neutral suspension supine casting method with the foot held in the subtalar neutral position with the "longitudinal and oblique midtarsal joints maximally pronated". We were taught that functional foot orthoses "prevented compensation for inverted and everted forefoot deformities" and that cork and leather orthoses could never be true "functional orthoses" since they were not made of plastic and had forefoot extensions. There were plenty more absurdities which we were all taught as students at CCPM, but I have, thankfully, forgotten most of them in my 30 year pursuit of trying to gain a better understanding of the biomechanics of the foot and lower extremity.

    Now, with all the above facts in consideration, my question to you then is as follows:

    Which of the following two situations show, as you say, more "bias"?

    1. A podiatry student being taught that there is only one theory of foot function and only one theory of mechanical foot therapy with no consideration of alternative theories being suggested as possibly having merit during their four years of podiatry school education.

    2. A discussion forum where all alternative theories are discussed and debated and where one theory becomes the preferred theory of treatment by the majority of those taking part in the discussion after their careful and thoughtful review and discussion of all possible theories?
  15. Jeff Root

    Jeff Root Well-Known Member


    Bias is represented by the implication that these are the only two options here. I don't see today's podiatry students in the U.S. getting a better foundation for making biomechanical treatment decisions than you did, and in my opinion the majority seem far less qualified than you or your classmates were. Right now I see an imperfect system being replaced by an absence of any type of system. I have spoken to a number of students, trained by Eric and others at CCPM, who were very dissatisfied with the lack of practical biomechanical training they received. Now they call my lab and others attempting to learn how to examine and treat patients because no one taught them how to do it in podiatry school. Personally I wouldn’t recommend bashing the biomechanical education at the schools during the 1970’ and 80’s until the schools of today can replace it with a superior product. If the theories on the arena are so far superior, then why isn’t it reflected in the schools of today.

    Forgive me if I seem irritated, but I am. I just spent over a dozen hours on the phone in that past week explaining to a podiatrist who just completed his residency what forefoot varus, forefoot valgus, forefoot supinatus, a plantarflexed 1st ray, hallux rigidus, functional hallux limitus and a host of other terms mean. Another said I can surgically reconstruct an ankle but I wasn’t show how to bisect a heel. That comment summed things up for me. As George Bush learned, be careful not to declare mission accomplished prematurely.

  16. CEM

    CEM Active Member

    if the only tool in the tool box is a hammer, every problem is a nail, from my limited learnings, i think way back then (not all that long ago) SJNT was all that was out there so all that could be taught, now, whilst the biomechanics of the human foot has not changed in 30 years or so the understanding of what is happening and the methods of treating it have.... it wasn't that long ago that the internet wasn't in existence
  17. drsha

    drsha Banned

    My foot typing is a morphological exam that is "cut and pastable" with Dr Roots exam and neiter of us is overlooking the effect of superstructure influences such as tibia varum (response to one of Dr Fuller's inaccuracies).

    I, like the Roots, think that as podiatrists, we should be focusing on this portion of a biomechanical examination, as this is the area of foundational biomechanical disease and needs to be repaired primarily before adding superstructure ORF corrections.
    After all, a quality therapist can help ovecome many superstructure problems without ever using "superstructure" ORF's.
    Once the foot is typed, positioned and trained to be a better supportive and functional unit, all training works better, more quickly and to a higher level whether it is Root's or Mine.
    This exposes a flaw for me in Tissue Stress as it seems to claim that the orthotic is a permanent entity that fixes everything. My orthotic is a prop and therefore has as a goal set that TS does not that once the foot is positioned properly on its own and functioning on its own the device can be weaned away.
    3. Radiographic evaluation (at the time it was part of the stand patient biomechanical evaluation) to identify any osseous anomalies
    4. Any laboratory or outside testing or referral, as needed

    As does Functional Foot Typing

    Although TSers claim this to be true, the orthotic fix is their focus (ORF's) not momentous changes due to muscle engines (MERF's)

    Eric says that he agrees, but he really doesn;t in fact and action.

    I think your treating the boys and girls too harshly.

  18. Jeff:

    I share the same sentiments as you regarding lack of knowledge in biomechanics of recent graduates. However, the time spent in practical application of biomechanics knowledge for podiatry students is now only a fraction of what it was previously for Eric Fuller and I and during residency they get even less since the focus is now toward surgery mostly. It is probably not the method being taught that is the problem, but rather the lack of time given to teach the method in practical application of biomechanics theory. I wrote an article for Podiatry Today magazine for next months Forum column that discusses this problem which you will probably enjoy.
  19. Jeff Root

    Jeff Root Well-Known Member


    The original question by Dr. Senatore asked about treating a rigid forefoot valgus. Forefoot valgus is a structural condition that was described by Merton Root that uses bisection of the heel in order to establish the everted, plantar plane of the forefoot relative to the bisection of the heel when the stj is in the neutral position and when the mtj is fully pronated. I recently spoke to a podiatrist fresh out of residency who doesn’t even know what forefoot valgus is, let alone how to recognize it clinically or even in the negative casts he took. You can’t blame the students for what they are not being taught.

    Today I happen to have the pair of cast from that same podiatrist for his very first patient in his new private practice and the casts are sitting on my desk right in front of me. The patient is a very high level sprinter who has a history of inversion ankle sprains and sesamoiditis. He is receiving orthoses for his non-spriting training shoes and for daily use. The casts have a significant everted forefoot due to a combination of a plantarflexed 1st ray and a forefoot valgus. As a result of the everted forefoot, the casts rest significantly inverted on my desktop. The podiatrist who casted this patient could not recognize the everted forefoot condition because they were never taught how to bisect a heel or what forefoot valgus or a plantarflexed 1st ray is.

    That is the state of podiatry today. How do you expect them to compare and contrast a theory when they weren’t even properly exposed to it? I will be glad to let Merton Root accept partial credit or blame for the state of biomechanical education in the 70’s and 80’s as long as you, Eric and the other leaders in the profession today are willing to except partial credit or blame for the quality of education of today’s students.

  20. Jeff Root

    Jeff Root Well-Known Member


    In your initial response to Dr. Senatore you said that you treat the injured structure versus treating “foot deformities”. In both systems, the pathological forces causing pain must be addressed in order to eliminate the symptoms. The reality is that both systems rely on the mechanical influence of the orthosis to treat those symptoms. Root theory was never intended to “treat deformities”. Root theory used structural and functional analysis and the anatomical structure of the casted foot to produce a device that would reduce or eliminate pathological forces. How else might the patient get better? If you are using a three dimensional, custom foot orthosis then you are doing much the same thing as Root did. The primary difference is in how you asses the patient, not what you treat.

  21. Jeff:

    In 1676, Sir Isaac Newton, in a letter to Robert Hooke, stated, "If I have seen further, it is by standing on the shoulders of Giants."

    If history shows, when I am dead and gone from this world, that I have made any useful contributions to podiatry and foot orthosis therapy, I hope it is also known that my accomplishments were only possible by building on the vast accomplishments of your father, Merton Root, and his colleagues.

    I will be giving a lecture in Ghent, Belgium next week titled, "The Evolution and History of Podiatric Biomechanics". In that lecture, your father and colleagues will play very prominently in my lecture. After my lecture, you should ask Dr. Spooner, who will also be a keynote speaker at the conference, if he felt that I had shown any bias against your father in this one hour presentation.

    Please don't assume that just because I criticize some of your father's ideas, that I don't respect his work greatly and think that he has done more for podiatric biomechanics than any single man in history. Too bad you can't be there....I think you would be very interested in the lectures that Simon and I, and the others, will be giving.:drinks
  22. Jeff Root

    Jeff Root Well-Known Member

    Root, Weed and Orien never wrote a book about orthotic therapy except for a casting instruction manual and a very short text about biomechanical examination of the foot. Normal and Abnormal Function of the Foot or Volume II as it is known, was a book about structure and function of the foot. I have taken the liberty of scanning and pasting pages 75 through 77 of Normal and Abnormal Function of the Foot to demonstrate to the skeptics how much "Tissue Stress Theory", although it wasn't called that, was central to their view of how pathology developed and how preventing stress on boney and soft tissue was the primary reason why orthoses worked. Although their thinking was that orthoses should resist compensatory motion of the foot, the reason for it was to prevent stress on tissue. See their own words below and judge for yourself!

    Jeff Root

  23. efuller

    efuller MVP

    Dennis, then you can cut and paste your explanation of how you incorporate tibial varum with SERM and PERM measurements. Or is this another thing that you can say that you do, but really can't?

    Dennis it appears that you don't understand how we apply tissue stress. You can look at orthotic reactive forces and explain how they affect load on the muscle and bone.

  24. drsha

    drsha Banned

    SERM-PERM is an upgrade, massage and maturing of Dr Root's pedal portion of his #3 exam as Jeff so well quoted it:
    "A non-weightbearing morphological examination the foot and leg to examine the range of motion, quality of motion and axial relationship of the major joints of the foot".
    It is a platform used to help determine the optimal functional morphological position for any foot (usually not the STJ Neutral Position IMHO).
    Once determined, it allows the development of an orthotic shell based on foot type and patient-specific needs positioned optimally so as to reduce the need for primary muscle engines to overuse themselves attempting to place and keep the foot in that OFP.
    Once this is accomplished, as I am sure is the same in TS, suprapedal biomechanical influences, such as tibia varum, are corrected with modifications (ORF's and/or MERF's) to the pedal orthotic and/or muscle engine training at that time.
    One difference I see between Foot Centering (a better comparison to TS Theory than FFTing or SERM-PERMing)) when dealing with suprastructural biomechanical pathology is that its primary focus is to change internal forces (MERF's) than orthotic forces (ORF's).
    Summarily, I do the same things as you do, at the same moment in time because pedal SERM-PERM has nothing to do with tibia varum existing, measured or being "fixed".

  25. drsha

    drsha Banned

    Eric: (Sorry to divert the thread with this one added post)

    It's interesting to me that you claim to know functional foot typing as well as I and that I, on the other hand, do not know how to apply Tissue Stress Theory.

    I on the other hand think that somewhere, there is useful and applicable information in both theories and that both of us continue to "make them up as we go along" influenced by each other and the EBM.

    The biomechanical communities will decide where the value is in both and which will dominate the future of biomechanics (or not).

    The place where I think we all agree (except for Jeff) is that although Rootian Biomechanics has brought us to where we are and his fathers place will always remain alike Newton's in physics, it is ready for redefining, upgrading, massaging and/or elimination (I can say the same thing for Dananbergian Biomechanics and Dr. Dananberg and I can't say the same thing for Glazian Biomechanics and Dr. Glaser).

    Foot Centering redefines, massages and matures Dr. Root's accomplishments and work and TS eliminates it.

    I guess that leaves Jeff as the judge of where his fathers work will go from here on in here on The Arena and elsewhere.

  26. Jeff Root

    Jeff Root Well-Known Member


    The problem as I see it is that none of these “theories”, including Root theory, is clearly or well enough defined. As a result, those who profess or attempt to practice it are practicing their version or their own interpretation of the theory. This makes it impossible for these theories to be taught to students or practitioners in any type of clear and consistent manner. In addition, there is significant overlap making it impossible to call them individual or independent theories, in spite of claims to the contrary.

    The current state of “podiatric biomechanics”, for lack of a better description, is a state of chaos. Looking at it from the perspective of an orthotic laboratory, we are dealing with practitioners with a wide range of different educational experiences when it comes to the practice of foot orthotic therapy. I find it increasingly difficult to communicate with younger practitioners because in spite of the flaws in how Kevin and others of his generation were taught, previous generations of practitioners were receiving better training in orthotic therapy than today’s students. I don’t profess to have the answer to this dilemma, but I am highly concerned about the current trend in podiatric, biomechanical education.

    Jeff Root
  27. Jeff:

    We now have many opinions on how the foot and lower extremity works and how the foot and lower extremity are affected kinetically and kinematically by foot orthoses. I don't perceive our current situation as being a "state of chaos", but rather as a difference in opinon as to what paradigm should be used to determine the intricacies of foot and lower extremity biomechanics and to arrive at an orthosis prescription for each patient.

    I don't think that very much separates us, Jeff, in how we evaluate and treat patients and how we communicate to others as to how the foot works. I use Root-style measurements daily and teach these measurement techniques to the surgical residents I train, even though most of them don't have a clue as to how to do it correctly. However, I also use and teach other measurement techniques which, I feel, allow me to better evaluate the internal forces and kinetics within the foot. I make the mental transition from Root style theory to Subtalar Joint Axis Location Rotational Equilibrium (SALRE) Theory multiple times on a daily basis and find both of these theories very valuable in evaluating an treating patients. I teach both of these theories to my students along with Tissue Stress Theory as a way to achieve optimal orthosis design for patients.

    I share your concerns about podiatric biomechanics education in the US podiatry colleges. For your information, I was one of the main advocates behind the development of the gait lab at CSPM that will now bear your father's name. In the five years I served as the "Biomechanics Consultant" for the Podiatric Medicine and Education Advisory Committee (PMEAC) at CSPM along with Drs. Don Green, David Mullens, Larry Oloff and with Sharon Diaz (President) and Albert Burns (Dean) also sitting in on our meetings, from about 2005-2010, my continual push was to get a gait lab established at CSPM (which is now being built), to get more hours of biomechanics education at CSPM than before (which has been gradually occurring) and to try and get the Biomechanics Fellowship reestablished (which has not occurred). Very few realize the "behind-the-scenes" efforts that occurred to get these tasks accomplished but the majority of us on that committee felt very strongly that the legacy your father, Merton Root, had created earlier at CCPM needed to be carried on as strongly as possibly at CSPM into the 21st century.

    Also for your information, I currently only teach about 5 hours per academic year at CSPM, giving lectures to the second and third year podiatry students on biomechanics and orthosis treatment of pathology. The students now are very smart, but spend probably one tenth the time during their fourth year, compared to the time that Eric Fuller and I did, devoted exclusively to biomechanics and orthosis fabrication techniques. Therefore, there there is no way these bright young podiatry students can become experts in foot orthosis therapy by the time they graduate with so little practical training in biomechanics and foot orthosis fabrication and modification.

    In addition, with no Biomechanics Fellowship program to train new leaders and educators in Podiatric Biomechanics now for the past ten years, there have been no post-graduate training in Podiatric Biomechanics here in the United States for a decade. The result in the next two decades, in my opinon, will be more people like Ed Glaser and Dennis Shavelson giving "biomechanics lectures" and less people like Ron Valmassy, Richard Blake, Eric Fuller, Larry Huppin and myself giving biomechanics lectures to podiatry students and podiatrists at podiatry schools and podiatry seminars here in the US.

    However, I still have a few good years left in me and I will continue to try to contribute as long as I can. The sad thing is though, Jeff, there will be few people who will be able to converse and teach "Root Theory" by 2032, which, I think, is a shame for the future of the podiatry profession.
  28. efuller

    efuller MVP

    I can see how you could claim an upgrade because it is arguably easier to perform the measurements (although the singular position of perpendicular forefoot to rearfoot is still going to be just as inaccurate). However, this comes with a loss of information.

    Now if you could explain the criteria used to find the optimal function position your system would be closer to being a complete pardigm.

    Again your theories lack explanation of what the optimal position is and why your particular modifications will move (physics explanation needed) the foot into this optimal position.

    An example using tissue stress. Shifting the center of pressure medially with a dual density midsole shoe will decrease the pronation moment from the ground so that the posterior tibial tendon will have less resistance and will not have to work as hard.

    The example above shows how changing orthotic reactive forces will change muscle forces.

    If the hours spent learning Root/ Weed biomechanics taught me anything, it taught me that tibial varum will have an effect on pronation end of range of motion (PERM) weight bearing. I believe Root/ Weed were correct in this assertion.

    I'm not quite sure what you assertion is in the sentence above is. It appears that you are saying that PERM doesn't cause tibial varum. It's the other way around tibial varum inverts the PERM relative to the ground. Addressing this concept is what is absent in the SERM- PERM measurements and what makes FFT a step backward form Root et al.

  29. efuller

    efuller MVP

    Tissue stress uses the work of Root, Orien and Weed. The reason that I say that you don't understand tissue stress is that you keep making statements like tissue stress eliminates Dr. Root's work. Dennis, I'm now going to give you an example to back up my statement that tissue stress uses the work of Root et al. Root, et al described the condition of partially compensated rearfoot varus where the STJ was maximally pronated with not enough eversion to fully load the medial forefoot. This condition will tend to cause high compression forces between the lateral process of the talus and the floor of the sinus tarsi of the calcaneus. This stress can be relieved with the use of both forefoot and rearfoot varus wedges

  30. efuller

    efuller MVP

    It's been almost 10 years since I was at CCPM. When I was teaching the third year rotation, I taught every student coming through how to bisect a heel. When some of them would ask how can you do this accurately, I would say that there is disagreement across podiatrists of where that line should be drawn. There is no one right answer.

    When I was a student, it was a really common lament amoung the students that the we didn't understand biomechanics. I heard many say that I got good grades in the class, but I don't understand it. I beleive that this can be partially explained by inconsistancies in what was taught. There are two different definitions of normal and they were not placed side by side and compared. Very few students could remember one, let alone both. The recent discussion we had here on the arena about orthotics "placing the foot closer to neutral" is another example of how people are confused by the paradigm and not necessarily thier instructors.

    I also lament the loss of time the students spend with biomechanics. Jeff, in your example above with the new practioner, I find the real sad thing is that he probably does not understand the difference between an orthotic with no post and with an orthotic intrinsic forefoot valgus post. I'm really curious on how you advised him on where to balance the heel bisection of that cast and why. (This goes to another area where ther is a problem with STJ neutral measurements. The combination of measureing forefoot to rearfoot in neutral position when the foot stands closer to maximal pronation and then you might have a rearfoot varus that could not tolerate the full amount of intrinsic post that the theory says that you should have. [Maximum eversion height was developed to solve this problem. An example of tissue stress building on Neutral position theory])

    I beleive that student confusion comes, in part, from holes in the theory. These holes have been ignored by instructors. Not addressing the holes leads to confusion, which leads to students not trusting the information. Later, when the students get into clinical settings they have instructors who don't trust the information and don't use the information. When I was a student there was a three month rotation in the 4th year where we were with instructors who believed and used biomechanics first. When I left CCPM, this had been completely cut from the curriculum and students would be very lucky if they found any clinical instructors who could go through the biomechanical thought process, any thought process, to arrive at an orthotic prescription. (Cast neutral, balance vertical)

    My answer for the chaos of multiple theories is that students should be given a concise one page description of each theory and then be told to start asking questions.

    My two cents

  31. drsha

    drsha Banned

    So are you saying that if a patient is functionally foot typed and is tested for Rearfoot SERM and lets say, from a bisection of the external heel (not the calcaneus) his/her RF goes sixteen degrees inverted and cannot go further (SERM reading = Inverted)
    Now you have a second patient with exactly the same RF SERM reading (He/she goes sixteen degrees inverted) but the patient has a fourteen degree tilt of the axis of the ankle inverted exposing a tibia varum influence.
    Do you mean to tell me that this patient will now be able to invert his STJ greater than sixteen degrees when SERM Tested?

    If not, please explain.

  32. Jeff Root

    Jeff Root Well-Known Member


    Let’s assume you bisect the distal third of the tibia and using the tibia as a reference, you then measure 14 degrees of calcaneal inversion with maximum stj supination and 7 degrees of calcaneal eversion with maximum stj pronation (total rom = 21 degrees) with the foot in the open chain (non-weightbearing exam). Now assume the patient has 5 degrees of tibial varum (which is a stance measurement taken with the stj in the neutral position while the patient is standing in their angle and base of gait). Since the distal 1/3 of the tibia is 5 degrees inverted, then in theory the maximum range of calcaneal eversion relative to the plane of the floor is 2 degrees (5 degree inverted tibia minus 7 degrees of calcaneal eversion = 2 everted heel position).

    Does that help answer your question to Eric about the influence of tibial varum on SERM and PERM?

    Jeff Root
  33. I am a Pedorthist in Canada, and when I was studying Pedorthics at the University of Western Ontario, we were taught most of the theories in Podiatry concerning foot biomechanics and orthotic therapy. I would say the majority of the focus was geared towards root's theory. In fact, in our practical examination it is mandatory that we must bi sec the heel and cast the foot in subtalar neutral using plaster of paris. My father Nick Sr. was actually a colleague of Dr. Root during the 70's and has practiced orthotic therapy for over 40 years using the root model and has been very successful. He has in turn passed down all his knowledge onto myself to continue the work and the theory into the future. In my personal opinion, it seems to work and many of our patients are very happy with our orthotics and keep coming back. However we have also intigrated a few other ideas from other Podiatrists works into our orthotics which have also improved our success rate for example, we use alot of "Kirby Skives" medial and sometimes lateral in the positive cast and that has shown to very effective in the treatment of many pathologies. So to Jeff and Dr. Kirby, the Root theory is alive and well in Canada anyway and I intend to keep preaching its values if until a new theory which I believe "proves" to be superior is published.

    Last edited: Mar 16, 2012
  34. Nick:

    Thanks for the feedback. I don't think that anyone is saying that Root's theories aren't helpful at producing very good quality orthoses that can help many people. However, the question, I believe, is do foot orthoses produce their excellent effects by the mechanisms proposed by Root et al using their theoretical framework or are they better explained by another theoretical framework?

    One of the problems is that none of Root's theories have been "proved" to be true. To my knowledge, there is not a single scientific study that shows that there is any correlation between the measurement of forefoot to rearfoot deformity and rearfoot varus/valgus deformity and foot function. In addition, since Root never explained exactly how he thought that foot orthoses worked in a written document (unless Jeff or someone else can show me otherwise), then we are left trying to piece together how he believed that foot orthoses produced their kinematic and kinetic effects.

    As a result of this confusion, we are left to try and determine why prescription foot orthoses, even ones that are very different in design from the Root Functional Orthosis, are so good at improving symptoms and improving gait function. Sometimes the clinical results are so much better with orthosis designs that do not follow the strict guidelines of the Root Functional Orthosis, that an inquiring mind should want to know why these different types of foot orthosis designs are so much better than what Root and coworkers originally recommended for treatment of various "foot deformities".

    Here is what I was taught at the California College of Podiatric Medicine during my student years of 1979-1983 and during my Biomechanics Fellowship of 1984-1985 as being the reasons that foot orthoses produced their therapeutic results. My biomechanics professors included Drs. John Weed, Chris Smith, Ron Valmassy, Jack Morris, Lester Jones, Richard Bogdan, William Sanner and John Marczalec, all former students of Merton Root, DPM, and adherents to subtalar joint neutral theory.

    1. Foot orthoses produce their effects by "preventing compensation for forefoot varus and/or forefoot valgus deformity".

    2. Foot orthoses produce their effects by "locking the midtarsal joint".

    3. Foot orthoses produce their effects by "preventing compensation for rearfoot deformities".

    4. Foot orthoses produce their effects by "making the subtalar joint function in the neutral position".

    Unfortunately, not a single one of these ideas have ever been supported or "proved to be true" by any scientific research.

    Therefore, if one want to be truly scientifically honest and not just believe something has been "proved" just because someone you respect, such as Dr. Root, said it is fact, you should then question how foot orthoses actually do work. You should also rightly question how many of the theories proposed by Root and colleagues actually are true and how many of them are just examples of intelligent speculation without a single piece of scientific research to support these examples of conjecture.

    I am not saying that I know all the answers, but I certainly do think that there are many more scientifically valid reasons why foot orthoses produce their impressive therapeutic results without needing to put forth the questionable hypotheses such as "locking the midtarsal joint", "putting the subtalar joint in neutral position", and/or "preventing compensation for forefoot and rearfoot deformities" as very many podiatrists still believe to be true.

    Yes, Dr. Merton Root gave us a good foundation by which to understand much of how the foot and lower extremity function together, but intellectual progress demands that we will need to discard some or even many of his ideas in order to coherently explain the complexities of foot and lower extremity biomechanics and foot orthosis therapy now and in the future. The scientific method demands this from us as researchers and clinicians.
  35. efuller

    efuller MVP

    16 degrees relative to what?
  36. drsha

    drsha Banned

    To A Vertical Bisection of The Heel as I stated in my posting.

    We can imagine the hands of a clock placed at the back of a heel where

    6 o' clock is vertical (stable)

    3 o'clock is 15 degrees inverted/rigid

    9 o'clock is 15 degrees everted/flexible

    Attached Files:

  37. drsha

    drsha Banned

    As I have stated previously, we have a lot in common. I couldn't agree with you more.

    My question is whether or not you would include The Foot Centering Theory of Structure and Function on your list of theories?

    I for one, would certainly include The Tissue Stress Theory.

  38. efuller

    efuller MVP

    To determine an angle you need two lines. From your writing it appears that your second line is a bisection of the leg. The point that both Jeff and I were trying to make was that tibial varum will move the leg bisection relative to the ground. So, yes, theoretically, there will be no change of SERM relative to the leg when there is tibial varum, but there will be a change of the heel position of SERM relative to the ground.

    Of course this points to a bigger practical question, and that is what has SERM to do with anything. Is there any prediction you can make about foot from the information you get from SERM? For example, in tissue stress we would predict that feet with the majority of body weight under the first Met head and hallux just after heel off will be much more likely to develop symptoms of the 1st MPJ and these symptoms will be relieved by reducing force in that location.

  39. efuller

    efuller MVP

    The reason that I would not include functional foot typing is that the one page description would not have enough information. All that we know about functional foot typing is that you type feet. No one has given any reason for altering treatment based on the typing system. Dennis, you could get some consideration if you were to write that one page description that included a rationale for treatment based on foot typing.

    For example,
    In tissue stress biomechanics you identify an injured structure and then mechanically model that structure so that you can devise a treatment plan that will reduce stress in that structure. Since, in the past you have been critical of tissue stress for "waiting for pathology", I will alter the theory a bit. In tissue stress you look at features of the foot like anatomical variations that may lead to high tissue stresses and then as a preventative measure you attempt to reduce those stresses. Specifically, a medially positioned STJ axis is predicted to lead to higher stresses on the posterior tibial tendon. Therefore, people with medially positioned STJ axes should get varus heel devices to shift the center of pressure medially to reduce the pronation moment from the ground. Of course prospective studies should be done to see if STJ axis position is predictive of increased risk of posterior tibial tendon pathology and outcome studies should be done to see if varus wedge devices were better than placebo. One advantage of this theory is that is easy to produce testable hypotheses.

    So, Dennis, when are you going to produce your one page description of functional foot typing. I did that description of tissue stress in less than 10 minutes.


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