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Kirby article and the midfoot

Discussion in 'Biomechanics, Sports and Foot orthoses' started by maxants33, Mar 15, 2012.

  1. blumley

    blumley Active Member

    hi a uk student who has been following this article with a great deal of interest. First off Dr. Kirby I wish to thank you for a well written and interesting post, although the concepts are challenging, I find them fascinating and very applicable to my early ventures into bio mechanics.

    From my understanding and the other papers I have read by Kirby et al. they are not attacking roots work, they are simply moving with the times as knowledge of forces etc acting on the foot are further understood. As a profession should we not be constantly looking to question and draw our own conclusions on all the current research available?

    Dr Sha I dont believe people are questioning your enthusiasm so to speak, but by suggesting max etc. are close minded is simply not helpful. As someone who is extremely experienced in the area, you should be looking to explain your theories and back them up with evidence. This would allow you to inspire the next generation of us who are simply trying to find our feet in a difficult field.

    all the best

    ben
     
  2. David Wedemeyer

    David Wedemeyer Well-Known Member

    First I’d like to apologize to Max and Kevin for hijacking this thread. I cannot sit idly by while Dennis tries to influence Max and portray himself as some altruistic soul to podiatry though, especially with the knowledge and interaction that I have had with Dennis Shavelson DPM:

    Dennis if you were the principled person that you claim and rallying the podiatric flag, why would you take that position as Biomechanical Director at ChiroSmart in the past? Why take the C.Ped course and exam either for that matter? Again, inconsistent, a pattern and majorly embarrassing to your new altruist persona hombre.

    The problem here Dennis is that I do read other podiatric forums and by admission a number your own colleagues denounce foot orthotic therapy and refer it out to allied professionals. Many insurers actually use vendors and preclude participating DPM’s from coverage and whether this is to avoid self-referral or a conflict of interest is not the point; the point is that C.Ped’s are qualified vendors and you are the only professional that I have ever witnessed publicly claiming otherwise.

    I recall you made that comment and I recall that it was said tongue in cheek. It doesn’t diminish me, my skill or interest one bit. My opinion of you had degenerated long before our conversations Dennis and the tipping point was when I learned your true motive for contacting me; attempting to use me as a conduit into the chiropractic profession. You stated it plainly Dennis and I stand by that publicly..

    Dennis don’t feign naivety, it makes you appear obtuse. I run a chiropractic office as well; time is at a premium as you well know. As well I had no interest in lecturing until very recently and have been strongly encouraged by colleagues to do so and it is a requirement in my new position. TS is not the only approach I am bound to either, much of Dr. Root’s work is still valid despite your assault on it.

    Is monitor another term for profit? A mere three months and you are the arbiter of opinion of the chiropractic profession Dennis? The truth is the lab you held this position in never made a dent in utilization by the profession. Three months is a very brief time span to build anything, especially a thriving lab business. I’d call your participation more of a flirtation and probably based on financial interest and not a true interest in teaching anything (just like your brief contact with me I presume). All of the podiatric labs that I am aware of accept casts from DC’s, PT’s, C.Ped’s etc. so why you feel the podiatric profession “owns” any part of the orthotic industry is beyond me. There are other qualified professionals dispensing foot orthoses and you appear to be the only one rallying the “podiatry only” flag.

    You can’t even explain your system to us; who is “dinosauric educationally, practically and biomechanically” now Dennis?

    Dennis the point is that the intent was there. You contacted me, all phone calls were made by you as I recall and you stroked my ego in a much more praising manner than you’re claiming now in an attempt to use me to further sales of FFT. Your abrupt change in position on allied professions stands; you turn on a dime and are inconsistent. Your intent was most certainly was to funnel FFT into the chiropractic profession, which makes your statements now very arrogant and contradictory.

    I’m surprised actually when Kevin ever addresses you, which is rare. You’re not on the same level academically or professionally and insinuating that you are is amusing because it is so absurd. Biomechanics is also not solely the province of podiatry and Kevin (and many others here on PA) have actually encouraged me rather than denounce and ridicule me for being a “non-podiatrist”. You are truly a minority of one Dennis.

    I about pee myself laughing when I read this Dennis and I am sure others do as well. What “science”; you have basically retooled someone else’s work but you cannot even explain it to us. Go ahead, answer Eric’s questions and dazzle us with some “science”. Again, patent’s mean nothing when you can start a fire but cannot cook the meat.

    Well you got me there Dennis, I am simply a chiropractor and a pedorthist and not a podiatrist. Most of my training is therefore beyond didactic. I do have the requisite training for insurers and Medicare to dispense and provide orthotic devices on par with you though. Because you denounce what you were taught in podiatric college, what is your training then, FFT which is a totally marginal idea in your profession? Pot, kettle don’t you think everyone?

    Dennis I am a clinician. I am also quite a bit younger than you are, therefore given my current position I may just eclipse your CV in due time. I have no plans to teach at a college and never have but that could change. Is a teaching position required to be a competent clinician? As for articles and possibly studies, they are in the works. They certainly won’t include negative, personal opinions of podiatry or any other profession and will be educational and describe reasonable and rational concepts that ALL professions can understand.

    .

    I stand by this and swear that it is the truth, publically. You never denied it either Dennis until now. Are you now denying saying this to me in our initial conversation last year?

    You contacted me and claimed that you wanted to introduce FFT to the chiropractic market. When you found out about my involvement with a new lab forming you suggested that the new lab could adopt FFT. When I balked you began your rabid campaign of denouncing all other professions as inferior to podiatry.

    If you held to your alleged principles now why would you contact a “Chiro/C.Ped in California” at all Dennis? Why would you send me your materials based on your stance now that only podiatrists are capable of understanding FFT? Motive; follow the money.

    You are all about the almighty dollar and your name and those reading know it. You’ve been caught Dennis. You’re not only a master prevaricator, you’re bad at it.
     
  3. David Wedemeyer

    David Wedemeyer Well-Known Member

    Yo that Kirby is 'aight'! I need to brush up on the Queen's English, that's the second time I've been referenced as "pithy" :D
     
  4. Max:

    Getting back to the much more interesting topic of midtarsal joint biomechanics, here is another illustration from a new lecture I gave at the student seminar in Ghent, Belgium a few days ago.

    Depicted is a model of a load-sharing arrangement consisting of the plantar fascia, plantar intrinsic muscles and plantar ligaments within the plantar foot which, acting together, help to prevent the longitudinal arch from collapsing. In addition, this plantar load-sharing arrangement helps to contribute to the spring-like function of the longitudinal arch in walking and running gait.

    The plantar fascia, plantar intrinsics and plantar ligaments all help to cause a forefoot plantarflexion moment by generating either passive or active tension forces on the plantar calcaneus and plantar forefoot. If one of these structures fail, then the other structure of this load-sharing system will be placed under more tension load and tension stress. However, complete arch collapse is prevented if one of these structures fails since the other structures are located in an anatomical position that allows them to share the increased tension load that occurs due to failure of the other load-sharing structure. An excellent example of the use of this model is in the mechanical explanation as to why increased strain on the plantar ligaments occurs with transection or rupture of the plantar fascia.

    The use of such simplified models in foot biomechanics, even though not exact in anatomical detail, allows the transfer of knowledge of biomechanical concepts much more clearly so that both the student and clinician can obtain a much better understanding of foot function as a result of their appropriate use.
     
  5. drsha

    drsha Banned

    So you had already formed an opinion and I assume voiced it in our conversations or else you lied. If you were truthful, why would I offer you to represent me into Chiropractic?

    David, I guess in your mind this represents a positive answer to my question of what you have accomplished in the teaching and academic world.
    In my mind it reflects an admission of your total lack of credit and credentialization in your profession, your credentialed have a high school degree and spend 100 hours in a pedorthic environment credential (to my recollection when I joined) or in biomechanics.
    Now that you are lecturing recently, can you give us a listing of your venues, topics and the evidence you applied in building your lectures?

    David:
    You're fantastic reporting of what my motives were when I attached to pedorthics and Chiropractic twelve years ago is astoundingly accurate.
    As you stated, I could not make a dent in procuring the Chiropractic or Pedorthic community to allow me to profit by accepting their orthotics.
    The only problem with your deduction and most of the rest of your character assassination is that I did not have an orthotic lab until about 2006.

    All I maintain is that as a profession, Podiatry belongs atop the Biomechanics Pyramid, another obsessive lie on your part. My patents will help to maintain that.

    You David, you.

    David:
    I'm forwarding this paragraph to my attorneys to decide if a defamation lawsuit is in order.

    Podiatry Management Magazine recognized "The Movers and Shakers of Podiatry in 2012".
    Both Kevin and I were both recognized I'm proud to say.
    In a nutshell they wrote of me "Internationally known authority on biomechanics and orthotics".
    If you actually had one fact that goes beyond your acid opinion and some kind of grudge that you presented on this post, it would justify your apology for diverting the thread.

    Example of Wedemeyer verbal diarrhea.

    More stuff to my lawyers.

    I have no plans to teach at a college and never have As for articles and possibly studies, they are in the works.
    That's quite a set of accomplishments David.

    Stop this crap or I'll see you in court.

    Dennis
     
  6. David Wedemeyer

    David Wedemeyer Well-Known Member

    You don't' even make logical sense Dennis. Before you wet yourself pondering legal action, be aware opinions do not constitute defamation, especially if they are true. Don't forget there are phone records and oh, how did I get your cell number if you're denying contacting me? You’re going to have a lot of plaintiffs considering the overall tone here and elsewhere towards you. Good luck with that.

    You've already made quite a name for yourself Dennis, no need to compound it by adding menacing internet bully to your resume. You don’t scare me and neither does your imaginary lawyer, go for it. It is not my motives being questioned here, it is yours. Numerous people have already seen you clearly for what you are and what you represent, so I won’t dignify your pusillanimous effluence with a response.

    Your buttons are so easy to push they should name a lab animal after you. I propose we call him “consummate a**hole”.
     
  7. drsha

    drsha Banned

    I rest my case.

    Editor Please.

    I will not dignify future postings of Dr Wedemeyer with responses.

    Dennis

    Could we return to posting on this fascinating and useful thread started by a student.
     
  8. drsha

    drsha Banned

    Kevin, I agree with your diagram and its value biomechanically. It is instructional and clarifying but IMHO, it lacks architectural accuracy and omits the structural forces in play coming from the structure that you call the longitudinal arch which is actually a Vault.

    IMHO, this reduces the applications that your drawing can have clinically.



    I am not as capable of the excellent quality provided by your drawings so please forgive the infantile one that I am attaching. I have additional thoughts that were stimulated by your illustration but I'll start here.
    The osseous structures are providing a certain amount of stiffness and bend into the force field displayed in your illustration.
    Entertaining their part in the equation opens up additional clinical avenues that would otherwise be obscured.

    In the left illustration, I have blackened in an orthotic shell that I would use to attach ORF's in order to balance the force field.
    I am calling this Kevin's Shell as it (like STJ Neutral) would be random and we would not want it to create a dorsiflectory moment upon the plantar tissues to add negative tissue stress.

    On the right, I have fleshtoned in an orthotic shell that I am calling Shavelson's Shell. It is cast in optimal functional position and places ORF's directly upon The Vault and obviates the forces of the soft tissues value, to some extent, by letting the shell provide the stabilization for the architectural structure.
    It uses architectural means to "shore up" the weak structure.
    ORF's can then be applied to the shell, prn, additionally.

    Summarily, theoretically OFP may have some added applications than STJ Neutral

    Dennis
     

    Attached Files:

  9. phil

    phil Active Member

    Dennis,

    I don't get your picture. Why is your orthotic a brown triangle? Why is Kevins orthotic a Black line?

    Would your orthotic really look that different? I think that Kevins orthotic would exert an orthotic reaction force to the plantar foot.

    Also, your new black arrows are all wrong. Your pink one almost makes sense.

    You've confused me.

    Phil
     
  10. A straw man argument built on an ugly modification of a very clear illustration...what will he think of next!!:bang::craig::eek:
     
  11. drsha

    drsha Banned

    for your copy

    yes.

    please email me @ drsha@foothelpers.com
     
  12. drsha

    drsha Banned

    Don;t know if I can help but:
    The color doesn't matter. I believe we all use the same $22 of material to fabricate an orthotic. I just colored them differently.

    Yes.
    Why do you think The U.S. Patent office says my device is an upgrade of the art?

    Phil:
    Everything I type on my keyboard must be understood to be a generality andd will change from one foot type to another.
    For example, for the flat/flat FFT, Kevins device and mine would be very similar.
    For the flexible/flexible FFT they would be dramatically different.
    So to respond:
    I think so too.
    I'm saying that before applying ORF's to the shell, my shell would apply more moment forces than his reducing the need for ORF's.
    That reduces compensatory pathology and allows for muscle engine training.
    Also, Wolfs and Davis' Laws react more to a Vaulted device than a flatter one actually, over time, vaulting the foot more even without the orthotic under foot. This changes the orthotic from having to be used forever into a prop whose goal is eventually weaning away and removal once the feet and posture respond tothe vaulting and the training.

    Although I am more advanced in the mechanics portion of biomechanics thanks my three years on The Arena, and especially to Simon and Robert, I am still trying to compete with masters.

    What I m trying to explain is that the bony architecture that composes The Vault of The Foot has a stiffness moment (my black arrows) that is offset by grf and the soft tissues that Kevin has left out.
    If my casting technique is gauged to support that stiffness and not STJ Neutral, then I can place the bones in an Optimal Functional Position which possibly I could call Optimal Functional Stiffness. Then theoretically, if I can cast in that position and provide a full contact shell that places the foot in that position, I would obviate the need for the tie beam in the truss-tie beam system and create it into an architectural vault that stands alone.
    My shell would be much more vaulted than a STJ Neutral one and it would vary, much more than STJ Neutral foot type specific.

    Possibly you (or someone else) can depict this in a drawing that would reduce the straw man nature of my argument or Kevin's willingness to discuss it rather than disprove it.

    Dennis
     
  13. drsha

    drsha Banned

    My next comment on Kevin's model relates directly to Foot Centering.

    He has drawn an architectural structure with two equal sides and a central keystone which is totally centered and needs no sagittal plane balancing. (first attachment)

    In reality, the Architecture of The Vault of The Foot is Off-Centered (second attachment).

    IMHO, This fact totally changes the engineering of his entire theory in that Kevin depicts the soft tissues as having a centered influence which they do not if redrawn closer to reality.

    My point, as Merton Root DPM taught us and as some of us have apparently forgotten, static posture and position play an important role in biomechanics.
    I therefore once again state that architecture (static position) has a role in biomechanics.

    Dennis
     

    Attached Files:

  14. Max:

    I would like to introduce you to two terms so you are not confused by some of the commentary that is occurring within this thread.

    The first term is the straw man argument. In a straw man argument, the person making the argument is basing some or all of their argument on a misrepresentation of the opposing person's position. Unfortunately, this is a common form of argument technique, being used in the past by Ed Glaser and now by Dennis Shavelson, here on Podiatry Arena. These individuals want the audience to believe that they make foot orthoses that are somehow superior in some aspect to the way I make foot orthoses, when, in fact, neither of them have a clue as to how many variations of foot orthoses I make for my patients. They simply are guessing as to how I practice, and are guessing very badly.

    Secondly, I want to introduce you to the concept of scientific modelling. Modelling is an approach used in scientific disciplines in which simplified systems are created to clarify a point, teach a concept or test an experimental condition. Modelling is widely used within biomechanics but has its limitations since it is, by its very nature, a simplification of reality.

    Many of the models I have created over the past quarter century are now used around the world to help teach biomechanics of the foot and lower extremity to podiatrists. I have included one of my early models from 23 years ago on subtalar joint axis location and rotational equilibrium from one of my published papers in JAPMA in the illustration below (Kirby KA: Rotational equilibrium across the subtalar joint axis. JAPMA, 79: 1-14, 1989). You can see that is obviously a simplication of the foot and leg, but it does very clearly illustrate the mechanical concepts that I was attempting to convey in this early paper of mine.

    Also, here is a great paper by R. McNeill Alexander, one of the world's leading authorities on animal locomotion and animal biomechanics. In this paper, Alexander helps to explain how and why models are used in biomechanics, as long as you also understand their limitations.

     
  15. Jeff Root

    Jeff Root Well-Known Member

    David,

    Structure and function are inherently linked. For example if a podiatrist does an osteotomy on the 1st met and creates a post surgical metatarsus primus elevatus, the patient might get a severe transfer lesion sub 2nd that can be worse than their original chief complaint. Why? Because altering the osseous structure changed the function of the foot (i.e. altered the distribution of plantar pressure during dynamic function causing increased shear sub 2nd). I think that’s why Root, Weed and Orien called their book “Normal and Abnormal Function of the Foot” and not Normal and Abnormal Structure of the Foot.

    It amazes me that the Podiatry Arena continues to be the host of a nonsensical debate about structure versus function. Both are equally important as you cannot have a one without the other. As in my example above, you would need to analyze structure post surgically to detect the presence of an iatrogenic metatarsus primus elevatus and you would need to understand the theory of how an elevated 1st met can cause a lesion sub second.

    It is also clear that those who profess to practice the tissue stress model still rely very heavily on a structural assessment of the patient. Unfortunately we now have a generation of younger practitioners who have no functional knowledge of structure and as a result, try to make a diagnosis with only part of the body of knowledge necessary adequately assess a patient. I can only hope that the pendulum ultimately swings the other way and that podiatrists will use all of the tools in their potential tool box.

    Jeff
     
  16. David Smith

    David Smith Well-Known Member

    Jeff

    With respect, while I agree that assessing the structure is a good indicator of Orthosis design it is not always a rule that can be applied, whereas the rule of identifying the pathological tissue and applying mechanical principles to change force actions, that reduce the stress that causes the pathology, can always be applied.

    Of course you have said the podiatrist should use all the clues at his disposal and consider function and structural form or mechanism and architecture and this is a good rule of thumb, visualising the form can give an intuitive indication of possible stress pathology.

    However the structural form is directly dependent on mechanical stress and will vary accordingly and so making conclusions by assessing structure becomes a chicken and egg problem i.e. is the form the cause or the effect of mechanical stress. On the other hand the cause of tissue stress and its potential pathology has only one direction and that is stress first then pathology, within itself tissue pathology does not cause mechanical stress.

    There are of course CNS neuromuscular responses to a mechanical intervention that can be a confounding variable, however mechanical intervention can also be implemented that will take advantage of known neuromuscular responses e.g. valgus posting to reduce a peroneal action that causes pathology associated with excessive pronation moments that actually reduces pronation moments by using the neuromuscular response to reduce peroneal action.

    This is also an good example of how assessment of foot structure might indicate the wrong orthosis design;

    I.E. the foot has a very lateral stj axis causes early and prolonged peroneal firing during swing in order to avoid eversion sprain at heel strike and so the foot strikes in an everted position and remains that way thru stance causing elevation of the 1st ray that leads to a stiff forefoot supinatus and plantar fasciitis that is apparently due to pronated foot posture and so structure assessment says to medially post the orthosis, which would be wrong.

    Regards Dave
     
  17. David Wedemeyer

    David Wedemeyer Well-Known Member

    Jeff your comments are always well thought out and always appreciated. I agree that structure and function are linked but, structure alone does not always explain the pathology was my point. Static assessment is important, as is dynamic I completely agree.

    It was previously taught that orthosis modifications would provide an observable change in the position of the calcaneus (structure) in vivo but we now know that is not factual. Still, we have those suggesting that it is true.

    Simon’s recent presentation in Belgium is example of the forward thinking on the subject. Does a visually pronated foot always pronate in gait or behave as predicted based on visual inspection always behave the same way on the ground? Does a rearfoot post "hold" the foot in that position? Does an orthotic "remodel" the MLA via Wolf's Law obviating the need for the device down the road? I say no, I suspect others will as well.

    So while structure and function are linked we cannot explain orthosis modifications via kinematic (position & motion) observation alone. We can however describe the kinetic effect (forces & moments) and seek to change the stresses that are causing the pathology via these effects.

    My point was that FFT is based on completely kinematic observations and that when you rely on such reasoning, the statements below are the result:


    The assumption that all Root devices or that all practitioners not using this "architectural lexicon" supply less than full contact orthoses or low arch devices is inaccurate an an unsupported opinion. Marketing, not known fact.

    Since Dennis and I don't play well together will someone please ask him for documentation to support this?
     
  18. Jeff Root

    Jeff Root Well-Known Member

    Yes, and you attempt to alter these stresses with a 3-D structural interface (an orthotic device).

    Jeff
     
  19. efuller

    efuller MVP

    The nice thing about using engineering principles is that you can calculate exactly how much difference is made by having unequal parts of the arch. However, the same equations are used, so that it is not that much different.


    I agree that architecture is important. Architecture is used in tissue stress. You have to think about the forces on anatomical structures in order to practice tissue stress. The difference between architecture and engineering is that engineering includes the loads placed on the structure. So, you need to look at the architecture of the foot on the ground. This is what makes typing the foot non- weight bearing suspect. There may be something to typing the foot, but it has to be shown to be relevant, or at least theorized to be relevant, to how the foot functions on the ground.

    Eric
     
  20. Jeff:

    I agree that structure of the foot is important and I think most others who are discussing these issues here on Podiatry Arena also think foot structure is important. I also agree with you that podiatry students should be taught about structural differences between feet and how to evaluate them.

    One of the problems is that structure of the foot, by itself, does not seem to be able to predict pathology. There have been no research studies, to my knowledge, that have demonstrated any scientific correlation between rearfoot varus, rearfoot valgus, forefoot varus and forefoot valgus and foot pathology or foot kinematics during gait. If there is no correlation, many clinicians may ask, why should I even bother taking these measurements if they don't seem to effect foot function or foot pathologies? Maybe you can provide an answer that is based on scientific research?

    Another problem is that differences in measurement techniques between examiners, in effect, produce "different structures" in the same foot. For example, it is not uncomon for one examiner to measure a 3 degree forefoot varus in a foot, while another examiner comes along and then measures a 3 degree forefoot valgus in the same foot. I have seen this numerous times when teaching students and podiatrists. The range of error of these measurements is so large from one examiner to another examiner, that it makes them virtually useless for predicting pathology or predicting function. Maybe you have some research that demonstrates otherwise?

    Until we can come up with a more accurate system of measurement, I believe that measurement of "foot deformities" will continue to be viewed as being possibly so unreliable from one examiner to another that it will be considered an optional exercise. However, I also believe that in an well-trained examiner, measurement of "foot deformities" can be very helpful for that clinician in deciding how best to treat that foot when comparing his/her measurements from one foot to another. For myself, I do a full biomechanical examination (including many "Root" measurements such as forefoot to rearfoot, relaxed calcaneal stance position, ankle joint dorsiflexion with knee extended and flexed, and first ray range of motion) on every patient that I make custom orthoses for. I still find these measurements helpful in many, but not all instances, in arriving an appropriate orthosis prescription for my patients.

    It is a difficult subject and I know where you are coming from, Jeff, since we essentially do speak the same language. I don't think we have a better system for structural classification of the foot other than the one that Dr. Root and his colleagues provided to us. Unfortunately, I don't have a good solution for this problem of how best to measure structural variations of the foot accurately and reproducibly from one examiner to another. This is one of the main reasons why the idea of designing orthoses around the concept of tissue stress is so attractive to me, and likely why it is attractive also to many others here on Podiatry Arena.
     
  21. Bikeflipper

    Bikeflipper Welcome New Poster

    Hi Kevin,

    there is a rumour that you are popping over to Salford Uni sometime this year, would be good to put a face to the posts

    Giles
     
  22. Giles:

    Chris Nester invited me over for a short visit to Salford while I am lecturing at the Biomechanics Summer School at Manchester in June. Time will be short though since I will be on a fairly tight time schedule while I'm there.
     
  23. drsha

    drsha Banned

    First. Dr Root and all who followed always understood that there was tissue stress that caused localized signs and symptoms of biomechanical pathology. How else would we explain it? He I and everyone else have always used tissue stress (and continue to). The TSers have given it great explanation, usefulness and appropriateness beyond Dr Root's explanations and terminology.
    If I understand your argument, unless a treatment protocol is followed 100% and has no exceptions it will not be applied by you in practice?
    You agree that Architecture has a place in biomechanics but because it is not 100% accurate (a fact), you have avoided its use.
    This goes to my claims in the past that IMHO, I am a better clinician than you because I have lower standards that have allowed me to use Structure as a part of my diagnostic and treatment plan.

    Agreed, we use it all the time (even before Kevin graduated podiatry college). Kevin did not invent scientific modeling as he seems to act.

    For TS, your ability to determine pathology is 100%. Using it as a diagnostic paradigm is excellent and I use it all the time in practice and when lecturing and blogging. I am a TSer.
    The chicken and egg in TS comes when after you determine the location, equilibrium and momentum of a given patients problem, you have no set rules as to how to treat the patient (other than some form of RF Skive). Although there is often consensus on the diagnosis using TS, there is rarely consensus on how to treat. That is the hole for me and others in TS. Clinical Applicability.
    Foot Centering, by adding Structure to Function when diagnosing and treating patients biomechanically, IMHO, is better than using TS alone.

    For years, I get very organized, consistent and predictable results using Foot Centering and TS to treat CNS, Peripheral and Sympathetic Disease. I receive referrals from top NYC Neurologists such as Michael Rubin MD, the chief of the Peripheral Neuropathy Section of Neurology at NY Presbyterian Hospital. My consultation reports include structural and functional information, a treatment plan and a prognosis for care.

    Agreed. So what?
    If you never knew how to diagnose or treat this patient (and those with his type) in practice, you would probably fail to properly treat 7-10 patients out of thousands. I suggest students refer these and other biomechanically sophisticated patients to someone with more biomechanical skill, art and experience (like Kevin) in their bloodline. Bringing these rare exceptions up repeatedly as if they occupied a large number of clinical cases one would see in practice is very confusing to students and those wishing to grow biomechanically.

    Dennis
     
  24. drsha

    drsha Banned

    This is true Eric but further defining the simple diagram with architectural correctness only makes Kevin's scientific model more understandable and useful as a teaching tool. Your explanation only makes sense if the structural part of Kevin's diagram had no usefulness which I argue it does and Kevin argues it doesn't.

     
  25. efuller

    efuller MVP

     
  26. David Wedemeyer

    David Wedemeyer Well-Known Member

    Eric I think that it is only fair that if Dennis is going to (mis)quote you that he preface his material by fairly presenting this gem:

    "I am a better clinician than you because I have lower standards that have allowed me to use Structure as a part of my diagnostic and treatment plan."

    Dennis Shavelson DPM 2012


    :eek:
     
  27. blinda

    blinda MVP


    Dennis,

    Thank you for emailing me the article. I happen to agree with much of what is stated within, in particular the title "Treating the mycotic infection alone will not always be enough for clinical success" caught my attention. However, I do have one or two queries that require clarification. Considering that this article has already been published, I would like to debate these openly on the Arena in a new thread, so as not to detract from this one.

    OK with you?

    Cheers,
    Bel
     
  28. drsha

    drsha Banned

    1. Like much of my work once visited, I am not surprised that you agree with much of what is stated in this article.
    2. Please start the new thread and raise your questions. I would be honored to respond in kind Bel.

    Please remember that like my patent application, which many of you still refer to as The Bible of my work, this article is many years old and we have come very far beyond its scope and practicality.

    My only fear Blinda is that The Arena Police will divert the debate to the personal diarrhea that still lives on this and other threads that I will continue to respond to once delivered.

    IMHO. those trying to prove me biomechanically impotent only reveal the insecurities and tentative status that they wake up with every morning when they look in the mirror.

    IMHO, those more secure like Craig, Simon and Robert have the class and confidence to back off and let the world decide my status in biomechanics.

    Dennis
     
  29. drsha

    drsha Banned

    Structure:
    1. Something made up of a number of parts that are held or put together in a particular way.
    2. The way in which parts are arranged or put together to form a whole; makeup: triangular in structure.
    3. The interrelation or arrangement of parts in a complex entity.
    4. Something constructed, such as a building.

    How would you discuss, alter, strengthen or support a structure without utilizing Architecture?
    Architecture:
    1. The art and science of designing and erecting buildings.
    2. Buildings and other large structures: the low, brick-and-adobe architecture of the Southwest.
    3. A style and method of design and construction: Byzantine architecture.
    4. Orderly arrangement of parts; structure
    How would you explain these things using physics and engineering?

    I agree but I add:
    Neither does function, by itself seem able to predict pathology (and treatment).

    I agree.
    That gives cause to two possible roads for working with structure. Either eliminate taking a structural or positional evaluation as the initial starting point or to upgrade it eliminating some of the master plan conjured and promoted by Jeff's Dad that is utilized and accepted worldwide.

    I have chosen to upgrade and change The Root Master Plan and IMHO, I sense that you would like us to eliminate it. Is that correct?

    I agree once again.
    That is why my foot typing method utilizes a position and not exact measurements. In this manner, the ability to reproduce the examination among various examiners comes up much more accurate as reported.
    One may state "a low profile" Rigid RF Type, one a "high profile" Rigid RF Type and yet others a "middle profile" Rigid RF Type but they all diagnose the Function RF Type as Rigid.
    Foot Typers worth a grain of salt never call a Rigid RF Type a Flexible RF Type, NEVER.

    I would like to soften your word to examination (a more accurate system of examination) making your demand more realistic and attainable.

    In that vein Kevin, do you have an accurate way of measuring the Subtalar Joint Axis that you state is so important in biomechanics and your skives?
    If you don't (and I don't believe you do, please consider softening your demands until you can prove your measurements as well.
    You talk lateral or medial POSITION ST Axis and not reproducible measurements just like the rest of us.

    I agree.
    That's why we need an understandable, teachable and recognizable paradigm for examination based on Dr Root's work and principles like The Foot Centering Theory of Structure and Function of which FFT is only the starting point.

    We all kow that interpersonal results and dogma has no place in EBM so are you stating that biomechanics is unresearchable while at the same time calling for research? Very circular.

    Here's where you really lose me and many other DPM's in your personal attacks of the work of others.
    You state that:
    "There have been no research studies, to my knowledge, that have demonstrated any scientific correlation between rearfoot varus, rearfoot valgus, forefoot varus and forefoot valgus and foot pathology or foot kinematics during gait. If there is no correlation, why should I even bother taking these measurements if they don't seem to effect foot function or foot pathologies"?
    Then you proceed to use them including rearfoot to forefoot measurement which IMHO was Dr Roots most inaccurate measurement.
    I suggest the reason you take Dr Roots measurements is to determine the architecture of the foot you are examining for shell design.
    Summarily, they are useful for you and not useful for Dr Root, Jeff and I or is it the other way around?

    If you don't have one on the tarmac, in your mind or on the drawing board, have you given up in your search for a solution.
    If you haven't, I suggest that DEMANDING definitions, explanations and research (which you yourself can;t produce for SALRE) you are killing potential replacements before they can be appreciated or blossom. This stagnates our ability to find an upgrade or replacement. Very unscientific IMHO.

    It's attractive to me as an Arena Veteran and biomechanicst as well but in addition, POSSIBLY by fabricating my tissue stress ORF's upon a shell conceived upon a functional foot type with foot type specific design specs as a seed may provide better clinical care. Prove me wrong!
    Dennis
     
  30. efuller

    efuller MVP

    When we do mechanical modeling we do look at the structure/ architecture. You can go into any college bookstore where basic engineering is taught and buy a book on statics and see how it is done. I don't see how you scientifically "strengthen" a structure without using engineering. Yes, you can have an arch and then throw an arch support under it, but there are other ways to make an arch more survivable than just throwing an arch support under it. Using engineering principles to do a load analysis can lead to those other methods.


    It's like that picture of the building that fell over. Architecture is the style, engineering is the science. You can't explain the style with engineering. Byzantine

    The neutral position terminology is useful in describing the structure and the treatments. Understanding how a 4 degree intrinsic valgus post alters the shape of an orthotic is important to understanding how orthotics can alter stress in the foot. It is useful to be able to communicate this information. So, I don't believe that the neutral position terminology or methods should be abandoned. I do believe that we should change the original explanations of how those orthotic modifications work.

    Dennis, the only reason that you have given for your system being an upgrade is that it is more reproducible. It probably is. However, it has less real world applicability. Dennis, you have yet to tell us how these measurements effect your treatment.

    Dennis, Did you see the other thread about the repeatability of STJ axis measurement.


    As I described above, we can keep the terminology and some of the concepts of the Root system. A partially compensated varus is a valid concept. A concept that is lost when going to Dennis' functional foot typing.

    There are plenty of explanations of SALRE. What we lack is studies backing up the explanations. The explanations lead to testable hypotheses. This is the major complaint that I have with functional foot typing. There are no explanations of why one foot type would behave differently than another foot type. We could create a foot classification based on foot length relative to a person's height. It is easily repeatable and understandable, but isn't predictive of anything. There is no reason why it would be predictive of anything. Dennis, is it really too much to ask that you provide and explanation of why you think foot typing should be predictive of anything? I'm sorry, if you feel this is demanding. If you haven't thought it through yet, just say so, and I'll stop asking.

    I'll get right to the experiments once you provide the protocol. So how do you modify orthotics based on foot types? What instructions do you provide for the people that work in your lab? Just send me a copy of those.

    Eric
     
  31. Jeff Root

    Jeff Root Well-Known Member

    In his book Biomechanics and Motor Control of Human Movement, David Winter wrote: “Any quantitative assessment of human movement must be preceded by a measurement and description phase, and if more meaningful diagnostics are needed, a biomechanical analysis is usually necessary”. Some cut: “The final interpretation, assessment, or diagnosis is movement specific and is limited to the examples given”.

    Perhaps the most common criticism of the work of Root et al is that the measurement system that was developed to analyze structure and function (open and closed chain motion) is not reproducible. However, many of the critics of this system readily admit that they use and rely on this flawed system due to the lack of a better alternative.

    The podiatry arena is filled with criticism of Roots work by those who demand or seem to proclaim to use a more scientific or accurate clinical model than that offered by Root et al, but to the best of my knowledge, these alternative clinical models do not contain any quantitative measurements. Without a system of quantitative analysis, how can one profess that any alternative to Root’s system is better or more accurate?

    Without Root’s system of examination and measurement, many of the basic terms used to describe the structure and the relative motion and/or relative position of the segments of foot and leg cannot exist. The challenge as I see it is to find valid scientific models that are clinically applicable and lead to more quantifiable and reliable diagnostic and treatment methods. The influence of Kirby et al has been extremely beneficial and has had an important impact on clinical practice. But given Winter’s statement “The final interpretation, assessment, or diagnosis is movement specific and is limited to the examples given” explains why Root attempted to describe and measure individual structure and why he developed functional theories about the relative movement (compensation) of the various segments of the foot and a method to apply his theories in a practical manner. From my perspective, this continues to be an interesting dilemma to watch.

    Jeff
     
  32. Jeff:

    I agree with your analysis. The work of Mert Root and his coworkers set the foundation for podiatric biomechanics and it is up now to the current generation of researchers and educators to analyze and try to improve on the work and ideas of Root and his colleagues for the benefit of our patients.

    I think you would have really enjoyed the lecture I gave in Belgium last week on the "History of Podiatry Biomechanics" since your father played a prominent role in the lecture. I will be giving this lecture again at Paul Scherer's Learning in the Vineyards Seminar on October 19-21, 2012. Hope you can be there.
     
  33. drsha

    drsha Banned

    Jeff:
    You are being very selective in quoting David Winter, the world renowned biomechanist.
    Obviously quantitative assessment requires measurements but Winter does not rule out qualitative assessment.
    In opposition, Winter states that a descriptive phase is necessary as well as a biomechanical analysis.
    Functional Foot Typing has a descriptive and analytic phase and avoids measurements because to date, no measurements of pedal biomechanics have been found accurate enough to produce important and high level evidence.
    Furthermore, in the
    Journal of Biomechanics
    Volume 28, Issue 6, June 1995, Pages 753–75
    Kinetic analysis of the lower limbs during walking: What information can be gained from a three-dimensional model?
    Janice J. Eng,
    David A. Winter
    Winter states:
    "the major portion of work was performed in the plane of progression since the goal of locomotion is to support the body against gravity while generating movements which propel the body forward". this quote verifies the need for sagittal plane correction such a Vaulting and villifies frontal plane correction of the foot fostered by Rootian and SALRE Biomechanics.

    So lets see if I have this correct.
    By your own admission:
    1. Root measurements are not accurate, reproducible and are flawed.
    2. Many of the critics however are using Roots system as they deride it
    3. Replacement or upgrade systems like FFTing must have accurate measurements or they shouldn't be visited or tested?

    Sounds to me that neither you nor those using Rootian Biomechnics want upgrades or change when it comes to structure and evaluation even though calling for them?

    Neither does Root or SALRE so why should others be judged differently in your opinion?

    Better and more accurate are poor chices of words. I never said better or more accurate.
    More understandable, more teachable, more marketable, more clinically applicable, etc
    Better is such a divisive way of putting things Jeff.
    As far as The Foot Centering Theory of Structure and Function.
    1. It uses both structure and function in its name
    2. It is more reproducible (ask Eric)
    3. It is more understandable
    4. It has many clinical applications (google The Biomechanics of the Diabetic Foot or The Biomechanics of Dystrophic Toenails)
    5. It adds architecture to engineering and physics as sciences that are of biomechanical import
    6. It eliminates rearfoot to forefoot measurement
    7 It adds a second forefoot examination that applies an examiner moment to give closed chain import to the test.
    8. It makes biomechanics more marketable in multimedia venues



    I agree but that is no reason not to improve and upgrade them into a more modern terminology as they are 40 years old and many are misspellings on word spellcheck (right here on The Arena such as orthotic, valgus, forefoot, etc. c

    I would add that IMHO, you are saying this without adding the caveat "without changing the Rootian Model" (my quote).

    [Quote[The influence of Kirby et al has been extremely beneficial and has had an important impact on clinical practice.[/Quote]
    I disagree as I see the same medial skives and valgus ff posts as he suggested decades ago.

    My problem with this statement is that you are watching, watching.
    Why not get involved?

    Dennis
     
  34. David Wedemeyer

    David Wedemeyer Well-Known Member

    For three years Dennis has been asked how his posts are different except in name. :confused:

    Three years later, still no answers but the plumes of smoke being blown up the collective arses of all of us are getting thicker and more frequent. ;)
     
  35. efuller

    efuller MVP

    Dennis, I'm impressed that you are aware of this excellent paper. However, you have yet to explain how "vaulting" (adding an arch support) has anything to do with sagittal plane progression or are you just latching on to Howard's work.

    SALRE and Tissue stress paradigms use modelling that can be applied in all planes. It is not just a frontal plane correction.




    It might be understandable if you finished explaining it. It is not understandable why someone would bother to type a foot and then not alter the treatment plan based on the type of foot. If it was something you do every day, it should be easy to explain.

    Eric
     
  36. drsha

    drsha Banned

    So, here is the next massage of Dr Kirby's modelling.

    He displays a centered arch (equal sides, central keystone)
    In fact, our feet are off centered (short rear, long fore, keystone offset proximally as I previous showed.

    Now lets model the off centered version for two functional foot types, The Rigid/Flex FFT and The Flex/Rigid FFT as in The Foot Centering Theory of Structure and Function.

    See attached one and two respectively.

    The GRF and grf reverses under the rearfoot and forefoot for these two FFT's making clinical decisions on where and how to treat the TS presentations much more focused and clinically relevant than for Kevin's simplistic Centered Model.

    In the Rigid-Flex FFT, you need to add plantarflextory stiffness to the forefoot pillar and peroneus longus power in plantarflexing the fore pillar.
    In the Flex-Rigid FFT, you need to add supinatory stiffness to the rear pillar and posterior tibial power in dorsiflexing the rear pillar.

    No need for RF correction in The Rigid-Flex and no need for frontal plane correction in The Flex-Rigid.

    We can do the same for Flex-Flex FFT, The Flat-Flat FFT and so on. Modelling the FFT's then allow the practitioner after FFTing a patient to have a starting place to shell construction that never looks at STJ Neutral.

    Paying attention to architecture leads to a different perspective that allows us to improve our shells to incorporate more ORF's, reduce the numbers and types of ORF's applied to the shell (TS) and increase the moment arms of our muscle engines so that they may be trained to apply MERF's into the mix from an internal source eventually allowing reduced use or removal of the orthotic prop.
    Voila, Correction!
    (especially for Robert to ponder)

    Dennis
     

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