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Tissue Stress Theory: Just a Variation of Root Theory?

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Kevin Kirby, Aug 1, 2015.

  1. Jeff Root

    Jeff Root Well-Known Member

    You posted it so why don't you help explain it? Not an unreasonable request on my part.
  2. Jeff Root

    Jeff Root Well-Known Member

    I asked the following question previously on the PA but got no response. About how many attendees were at the 2015 BSS?
  3. drhunt1

    drhunt1 Well-Known Member

    And yet here you are, Kevin...disparaging those that disagree with you, (or letting others do your dirty work for you), espousing your own dogma while ultimately solving nothing. What has TST ever resolved? You answered your own question about TST Vs. Root Paradigm on the thread that was shut down...and that was...no...Root Principles have not been replaced by TST...and if anything, it is adjunct information offered at CSPM by yourself. No one I know over here in the States uses it, let alone has even heard of it. Don't get me started on the level differences between Podiatry here in the States vs elsewhere...but Kevin, you haven't gained traction here lecturing about it. Good thing for you that you have an active/captive audience elsewhere to listen to the theory. Perhaps you should read more carefully the words by Darryl and Dr. Orien...they were being thoughtful and nice. I don't share that quality. Hope that helps.
  4. Rob Kidd

    Rob Kidd Well-Known Member

    My point is very simple - if it is alive, or ever has been alive (eg fossils), the subject is biological. I guess that I am biased as that is essentially my background. And of course biology "borrows" from all other disciplines. An example from when I was a PhD student in anatomy was that really quite complex quantitative methods were being used that were first found in other disciplines such as Geology. An example in the use of finite elements to examine form/function relationships - this was first noted, at least in my life, in fault plane solutions. I would really note choose to get bogged down in the really quite ridiculous s/t neutral issue, but from a scientific view point one cannot use itself to define itself - otherwise one is bound up in a classic tautological argument. Thus, to define pronation and supination as movements away from neutral, at the same time as defining neutral as being that position where it is neither pronated not supinated is a classic scientific tautology and anyone with even a basic scientific education should have known better.

    From Derby eh? I am from Buxton - well, a million years ago. Currently I am on the Central West Australian coast. Rob
  5. Rob:

    I clearly remember squirming in my seat in class as a 23 year old podiatry student hearing that Root's definition for subtalar joint neutral position was that position where the subtalar joint was neither pronated nor supinated. Sounded like a pretty poor definition to me 35 years ago....and it still does today.:cool:
  6. drhunt1

    drhunt1 Well-Known Member

  7. Ian Linane

    Ian Linane Well-Known Member

    Jeff. Re BSS.

    I would conservatively estimate around 3-400 (though estimating isn't my best skill!!!) attendees on a 2-day conference and it being a mixed discipline attendance (pods, osteo, sports therapists etc.). I've attended these conferences on and off for at least 15 years. I certainly find the recent ones more inter-disciplinary in nature and more dynamic in terms of interaction. Of particular note for me (probably my bias) has been the inclusion of physiotherapy researchers in the area of mechanics/orthoses/rehab.
  8. Rob Kidd

    Rob Kidd Well-Known Member

    'Still waiting for someone to explain what "face palm" is. I have spent a life (nearly) in science dealing with obstructionists - please not another. Rob
  9. ]
    I can help with that, being as I am all down wid da youf and culture ting.

    A facepalm is an expression of frustration. Like this. [​IMG]
  10. That's interesting, it's one of the more commonly used models over here. Certainly it's part of the undergraduate program. Can't think of anyone who's never heard of it.

    If what you say is true, you may be correct about the differences between the states and elsewhere. . :rolleyes:

    But I doubt it is. I rather suspect you are extrapolating your own range of experience onto others.
  11. Rob Kidd

    Rob Kidd Well-Known Member

    Well T/Y Rob - now I understand, at least sort of. When I was Academic Mentor of a residential college (I did 5 years), I made it my business to know the jargon, which in those days was everything from "LOL" to "pulling a train" - yes I had to deal with that from time to time - not something one would normally associate with pretty young things at university..........
    What I still do not understand is whether the young man in question was agreeing with me or was upset by me. And you what, actually I really do not give an excrement.
    Last edited: Aug 5, 2015
  12. Urban dictionary is your friend. Dealing with paeds, up to teenaged, I often had to excuse myself from the room and seek enlightenment.

    I believe the individual in question may have been trying to communicate that he takes issue with your views on sub talar neutral. I could, however, be wrong.

    Personally, I find it mildly depressing that we are even still having this conversation. But there we go. Progress is never easy, but it is worth fighting for.
  13. blinda

    blinda MVP

    Had to look that one up...wish I hadn`t :eek:
  14. Rob Kidd

    Rob Kidd Well-Known Member

    Rob - as always you are enlightening. I have to say in my own prosecution, that I have spent more time in destruction than construction. However, I honestly believe I have done it well! My mentor in science (he walks on water in his spare time), on the result of discussion of some hominid fossil or other, usually quite provocative; I would say to him - I am too old to care, he would say: I have never cared. He had more degrees than the rest of arena put together, including a DSc from Birmingham. Next time I am in the UK, I must make the effort to share a foaming pot or six with you, Rob (the other Rob)
  15. Rob Kidd

    Rob Kidd Well-Known Member

    Sweety, when you are academic mentor, one has to deal with the lot, not just the bits you like!
  16. blinda

    blinda MVP

    Please don`t tell my mentees, Honey ;)

    Oh, and I see you`re offering to share an ale with Isaacs when you`re next in the UK...remember you promised me one too?:drinks
  17. Rob Kidd

    Rob Kidd Well-Known Member

    Take is as read - my only humble apologies is that I left last year without settling your delerium tremors - I will do my best to make sure it does not happen next time. However, I have no idea when next time will be.......
  18. Destruction is as important. One must let go the past to grasp for the future. I think you do yourself a disservice however.

    I don't believe for a minute that you don't care. I think you care very much, about what is true. I can believe that you don't care much about what other people perceive as true, or whether they think you're right or not. . ;)
  19. drhunt1

    drhunt1 Well-Known Member

    Couldn't have stated it better myself. On point.
  20. Rob Kidd

    Rob Kidd Well-Known Member

    Dear Robert - you are as right as always. My story of rebellion started in 1980 when I joined the staff at The Northern College. It had 28 staff - surely the biggest school of Pod in the world? There are two essential stories that come out of this, but the relevant one is that I was appalled, absolutely gutted, by the general level of brown-nosing by staff, which was not in the best interest on the students. I made a pact with myself then, that I would never do anything ever that was in not in the best interest of my students, I was 25 then, I am 60 now - nothing has changed that. However, I was labelled "Trouble" by many - and for a few years my career stagnated, while many went past me. In the end, the truth sorts itself out and time tells the truth. If in doubt, ask the students - they tell the real truth. Most of those staff are dead now, but the odd one is still alive so no names, no court cases...............................

    I take a simple view: what is their publication output, their grant record, their foreign lecture delivery. These are the hallmarks for a proper academic: do they fullfil these essential criteria? Or not?

  21. The life of a contrarian is not any easy one. And inevitably it does mean one makes some horrendous gaffes along the way. But at least they are OUR gaffes, made based on our own assessments and on our own accounts.

    Certainly ones record is important. However I am always suspicious of hitching the wagon to any star. After all Brian Rothbart has published in many journals in several countries, including japma, and has lectured extensively in several countries. However to paraphrase the bard, the love that I bear him permits no better greeting than this, he is a villain.

    I always think the way in which an argument is presented tells you much about its content. Paynes law, or a slight extention of it, is a useful guide.

    Even a blind squirrel finds the occasional nut. And even the great and good get it wrong.

    Pleasure talking to you Rob. As always. :drinks:
  22. efuller

    efuller MVP

    Daryl, I see at the end of your post that don't intend continue this debate. I truly wish you would. I have to disagree with you in that there is a difference between the tissue stress approach and the neutral positon approach. Yes, we both identify the injured structure and we try to reduce stress on the injured structure with our devices. Bill Orien in his letter mentioned how you needed to "Lock the midtarsal joint" to relieve stress on the plantar fascia. This illustrates the difference between neutral position theory and tissue stress theory. These two approaches use different logic in explaining how the threatment works. The two paradigms will often use the same treatment, but sometimes have different explanations of the treatment. The explanation of the treatment is a particular weakness of neutral position theory. Neutral position theorists can't agree on the theory of how the orthtotic works. (Balance the cast vertical, so that the heel will be vertical, lock the midtarsal joint, support the deformity, put the foot in neutral position, push the foot toward neutral positon. You can find someone who will claim to be a neutral position theorist who will defend at least one of those reasons.

    In tissue stress, there is a study that shows that a forefoot valgus wedge can reduce tension in the plantar fascia. So, we will use a forefoot valgus wedge, or an intrinsic forefoot valgus post in our orthothic when we want to treat high tension in the fascia. You don't need to measure a forefoot to rearfoot that is in valgus to use a forefoot valgus wedge. The theories are different.

    Minor point: I would rather have a brief description of the theory rather than attach a hame to it. Medial heel skive, versus Kirby skive. I have a hard time remembering what you call the Root postulate. But, when you spell it out, I remember it quickly.

    In reading Eric Lee's study of Root and neutral position theory. If I recall correctly one of the uses of neutral position was to find a way to differentiate feet from one another. There is an important point here, Not all feet function the same and if we are going to study them, we can't treat all feet the same. I'm not sure that neutral position and forefoot to rearfoot relationship are going to be a good way to differentiate feet. There is the measurement accuracy problem. I don't remember off the top of my head any other uses for neutral position. So, to answer your question: should there be a neutral position? I would answer with a question. What do you want to do with neutral position?

    How are people going to decide which research path to take if they don't see debate about what is currently thought. The discussion should lead to research.

  23. DrBob

    DrBob Active Member

    Strewth! In one of the posts above I think someone used the term "waxing lyrical"? Well, there seems to be an awful lot of waxing lyrical (opinion), there is reference to some science (thanks Bob K), but there is precious little, if any, reliable measurement reported! If you can't measure it reliably, and report it objectively, then you really don't know what's going on and you are all guessing - educated professional guesses, agreed, but not substantiated fact. Why not try to find a new approach rather than argue about the past?
  24. DrBob

    DrBob Active Member

    Strewth! In one of the posts above I think someone used the term "waxing lyrical"? Well, there seems to be an awful lot of waxing lyrical (opinion), there is reference to some science (thanks Bob K), but there is precious little, if any, reliable measurement reported. If you can't measure it reliably, and report it objectively, then you really don't know what's going on and you are all guessing - educated professional guesses, agreed, but not substantiated fact. Why not try to find a new approach rather than argue about the past?
  25. rdp1210

    rdp1210 Active Member

    As you may note, I have only written about 2% as many posts as some of the common contributors. Time spent here means time I can't be doing something else. I certainly am not going to convince you to reconsider your position. However you did write well, and I felt it deserved some comments.

    As I continue to read your thoughts about McPoil-Hunt theory I feel that I can incorporate your thoughts without giving up some Root principles. I feel that I can see a meshing, not a contradiction of priinciples.

    As to the need for a neutral position, Dr. Kidd wants to stay on the fence as to the need -- he only seems to reject the Root definition. He is free to do so -- I scratched my head for many years about this tautology definition, and now I realize how ingenious the definition is -- it is really an existence definition. I now realize if we want to classify the static function of feet into those that are pronated or supinated, we have to have a neutral position. Now if you want to go back to the Bankhart idea that Levitz and Sobel espoused, then you can say that the normal position is the fully pronated position then you only have to find how many degrees of supination any foot is standing in. I realize that midstance and kinetic gait may not be identical, however, let's face it, a majority of the Western culture use the foot more for standing than for walking.

    Now Levitz-Sobel accused Root of stealing and misinterpreting the Desai-Wright definition. This would be easy to think until one sees that Root's Basic Approach paper was published one month prior to the Desai-Wright paper, so he would not have had access to it.

    I do agree that those who call themselves Root followers all have their various flavors of Root. But then again, we can say such about those who follow Jesus and also those who follow Mohammed. All here interpret Root in light of their experience and who they have heard lecture that say they knew Root. Listening to Kevin and then listening to me, you wonder if the two us knew the same person. I had a totally different experience with Root and with Weed and with Orien. Those who ever attended a Mert Root conference know that even Weed and Root would have differences of opinions at those conferences. As I have pointed out before, and Orien recently wrote publically, their seminal work was a beginning -- not an end. So with that, I feel that we are all welcome to take that beginning work and to add, to subtract and to modify, wherever the research takes us. What I see in our discussions are disagreements as to what each of us have added, subtracted and modified as to either techniques, or reasonings, or even totally new additions. I am not going to ever take a stance that it is 100% true or 100% false.[/QUOTE]

    Your example is a classic example. Did Root say that inversion of the forefoot to rearfoot increased the tension in the plantar fascia? I don't think so. He did state that the forefoot being in its inverted position made a foot unable to efficiently transfer weight to the medial side of the foot during propulsion. Now I believe it was first MacConaill that first talked about the twisted plate theory, and then this was expanded on by Saraffian. I am not going to disagree with either of these great thinkers. However I see not a complete theory in your statements, I see principles. You have no way to predict how much wedge to add, you just start adding wedges, until the patient says, "that's wonderful". Sorry, I don't see a whole new theory. You have added a paragraph into the Root book.

    The Root Postulate: In static stance, the midtarsal joint should be at its pronation EROM (in all planes).

    This is the one truly UNIQUE idea of Root-Weed-Orien.

    I have stated many times before - and hopefully no one will ever think that I didn't - there are major problems with the application of Root measurement ideas into a clinical situation. That does not mean that the ideas are totally wrong. It means they need to be examined as to why there are unreliability problems. Now Hillstrom did a nice job showing that good instrument markedly decreases the reliability problem of the posterior calcaneal bisection lines. We continue to see the critics of Root still using their eyeballs to draw bisections, and then throwing stones. I have maintained for many years that the Root volume I book is a concept book, not a step-by-step technique book. He left many things undefined and unexplained. There is so much to further define. I have put forth many times the question, "why would you want to draw a bisection on any item?" People only want to either accept or discard goniometer based on so many studies that continue in studying using poorly defined techniques. We need better techniques, we need better instruments. However if I adopt McPoil-Hunt theory, which you espouse, then I need no instruments, I need only my thumb to palpate the STJ axis, then I start adding wedges. Your lack in replacing the Root goniometric ideas with a better goniometric system, makes me say, "Yes, I can accept tissue stress principles, but they are add-ons, not replacements for Root ideas." I am a better practitioner by using them all. I also accept and mesh the FHL ideas with all the other ideas. Hopefully, when a patient visits my clinic, they find a practitioner who has a finely tuned orchestra, and who continues to add new instruments, and new overtones and harmonies.

    In summary, do I practice tissue stress priniples? Yes? Has Tissue Stress replaced Root? No. With that, I've got to get to work -- today is wound day. It is a biomechanical quagmire and nightmare.

    Best to you,
  26. Rob Kidd

    Rob Kidd Well-Known Member

    It is late: I will reply tomorrow, Rob
  27. Rob Kidd

    Rob Kidd Well-Known Member

    Daryl, It is not a question of sitting on the fence - I do not sit on fences per se. The truth is that the Root definition of neutral is laughably rubbish,no matter which way we look at it. That is, whether we start from that we have discussed - which is undoubtedly tautological, through to the even more laughable calculation of the neutral position with a 1/3:2/3 calculation. I am not fence sitting - I simply want to start off from a solid piece of theory - which so far, is sadly lacking. And me being me, the proselytising of pseudo-scientific rubbish as if it were fact has not done the profession any good in the long term.
  28. rdp1210

    rdp1210 Active Member

    Now that we know what you don't believe -- what do you believe? What are your criteria for normalcy? Do you have any scientific methodology for clinically approaching foot dysfunction that produces pathology? You consistently call other people intellectual-midgets, yet can you offer me, the average clinician practicing daily, something that is better? Ed Glaser thought he could, and I even tried it. Didn't work! Eric keeps saying he has something better, but I just have added his principles into everything else I'm doing. He has produced nothing that can lead to any type of predictive system.

    Call me some type of pseudo-intellectual or any other belittling name you want, but as a day-to-day clinician, having to make judgements about whether a foot is pronated or supinated, I find that there is a need for a neutral position. I asked you before, to define the number zero, without getting yourself into a tautology, but you failed to take that challenge up. (I find it interesting to listen to talks about what constitutes the vacuum of space, as greater minds than mine explore what nothing is.) If you look at my 1983 paper (which you probably rubbish as pseudo-whatever) you will see the actual data I collected. Notice that I utilized a method of finding neutral position of trying to find that point that Jeff talked about, which is the way that Mert personally taught me. I find it interesting that a lot of people did not have the 2:1 ratio, but the average for the population was a 2:1 ratio. Right now, I know what Root felt. I also believe that we can better define what he felt. If Eric would listen, I believe it would morph very nicely into a tissue-stress definition for the neutral position. Certainly there have been studies about the joint congruency, that throw doubt on that particular explanation of neutral. But nobody is willing to sit down and really analyze what Root was trying he is feeling is happening.

    BTW - thanks for the reference to Darcy Thompson. I had never read anything by him before, but have enjoyed what I've read so far. Haven't found anything earth shaking yet, but it's good. One of the things I haven't looked at yet is whether we should classify feet as to how they fit the golden ratio.

    Keep throwing rocks,
  29. Daryl:

    There are two problems with the "one truly unique idea of Root-Weed-Orien".

    First of all, since there is no single midtarsal joint axis, but rather a large number of instantaneous axes of motion that are dependent on the external forces and internal forces acting across the midtarsal joint at any instant in gait. In addition, the midtarsal joint doesn't always dorsiflex-abduct-evert which would describe a "pronation motion" and what you have described as "the one truly unique idea of Root-Weed-Orien". As per the research of Nester et al, the midtarsal joint may also have an axis that allows dorsiflexion-abduction-inversion and plantarflexion-adduction-eversion (Nester CJ, Findlow A, Bowker P: Scientific approach to the axis of rotation of the midtarsal joint. JAPMA, 91(2):68-73, 2001).

    Secondly, the midtarsal joint does not "lock".....ever. The midtarsal joint, like all other joints of the body are restrained by viscoelastic structures (ligaments, tendons, muscles) that will deform more with increasing load with stiffnesses which are load-rate dependent. Therefore, Root, Weed and Orien's contention that there is an "end range of motion" in the midtarsal joint (or any joint for that matter) is a biomechanically inaccurate statement. This is especially true for the midtarsal joint, which is routinely subjected to loads that are over 2-3 times body weight. Rather, the midtarsal joint is best mechanically described as a variable stiffness spring, not a locking structure has has a defined "end range of motion". This variable stiffness spring idea of the midtarsal joint was clearly demonstrated in the research of Ker et al from nearly three decades ago (Ker RF, Bennett MB, Bibby SR, Kester RC, Alexander RMcN: The spring in the arch of the human foot. Nature, 325: 147-149, 1987).

    Therefore, I suppose this one last "truly UNIQUE idea of Root-Weed-Orien" is false also.

    Now that we have that out of the way, can we move on and quit trying to support the unsupportable beliefs of men we admired just because we respected them for what they did and who they were?
  30. Jeff Root

    Jeff Root Well-Known Member

    Funny that today the following should show up on Facebook as soon as I logged in. It was written by Kevin Kirby on his professional Facebook page (bolding by me):

    How does one determine the presence of an "everted forefoot deformity (i.e. forefoot valgus deformity)"?
    1. What position is the STJ placed in when determining the presence of an "everted forefoot deformity (i.e. forefoot valgus deformity)"? Is it Root's STJ neutral position or some other position knowing that changes in the position of the STJ will alter the FF to RF relationship?
    2. What position is the forefoot placed in when evaluating for any inverted or everted "forefoot deformity"? Is it Root's recommended maximally pronated position of the MTJ or some other position knowing that changes in the position of the MTJ will alter the FF to RF relationship?
    3. In order to determine the "degree" of the deformity, does one measure the FF to RF relationship or just eyeball/estimate it? What anatomical reference is used to determine the degree of any FF deformity? Is it Root's neutral position heel bisection or is there some other anatomical reference?
    4. How does one determine the presence of "high degrees of rearfoot varus deformity" without measuring STJ ROM and using Root's STJ measurement techniques?

    We keep seeing criticism of Root's theory of the neutral position of the STJ but these concepts (FF to RF conditions/relationships/deformities) are dependent on it. Has TST supplanted these concepts. Apparently not according to what was written by Kevin Kirby, the person who started both of the threads about this topic. I think we can put the subject to bed since the question has been answered in the negative many times in these discussions. Do we need to refine our theories? Yes. Do we need to waste more time debating if "Root Theory" (even though we know there is no such thing as "Root Theory") is dead? No, Root's concepts of FF/RF relationship, STJ neutral position, etc. are alive and well and in use every single day.

  31. rdp1210

    rdp1210 Active Member

    Kevin- you missed the whole point. The question is not whether the Root Postulate is or is not correct. The question is a definition of what it is.

    I will take time later to discuss your points as I see you setting up a straw man argument.

  32. Jeff:

    [For all those following along, here is the Facebook page Jeff was talking about. https://www.facebook.com/kevinakirbydpm ]

    I use neutral position of the subtalar joint routinely in my clinical practice and in my writings on foot and lower extremity biomechanics and foot orthosis therapy. In addition, I use the subtalar joint neutral position and teach how to determine its location to podiatry students and the podiatric surgical residents I train. I think the subtalar joint neutral position a valuable idea which helps us determine and better discuss a position within the subtalar joint range of motion that is helpful as a reference frame to better determine foot structure. However, Rob Kidd is correct in that the definition of subtalar joint neutral of being "neither pronated nor supinated" is tautological and is therefore, as a result, a poor definition.

    I define subtalar joint neutral position as being the midrange rotational position of the subtalar joint where there is a flattening with the arc of curvature within the range of motion of the subtalar joint that is approximately one-third of the total range of motion of the subtalar joint supinated from its maximally pronated position.

    In addition, if it means anything to you, I certainly don't hope that all your father's ideas are "supplanted" (contrary to what some people may believe) since I still use many of your father's ideas in my own busy clinical practice. I believe that I have achieved much more because of the hard work and ideas taught by your father, John Weed and his students.

    That being said, I do think we need to move on for the good of our profession and be open to new ideas. These discussions are important and they need to occur, even though they may be unpleasant, in order for all of us to move ahead toward a better understanding of foot and lower extremity biomechanics. I'm sure you feel the same.:drinks
  33. Jeff Root

    Jeff Root Well-Known Member

    The definition might be problematic in some ways but there are many practical benefits from the concept and the definition of the neutral position of the STJ.

    That is a practical definition but not a scientific definition. If the STJ only exhibited pure supination and pronation, which it may not necessarily do, then the problem comes not when we try to determine if the STJ is supinated or pronated, but rather when we try to determine if the foot as a unit is supinated or pronated as a result of the position of the STJ. I believe this is a critical point if you really consider it. When we clinically evaluate the STJ, we are looking at the STJ's influence on the foot as a unit. We are not isolating the joint itself. So in a practical sense, the STJ neutral position is that position in which all signs that the foot is supinated or pronated are at their least. The neutral position is a theoretical point of the joint but a practical range since we can not always determine the exact point at which it occurs.

    I think the one thing we all have in common is summed up when you said "I do think we need to move on for the good of our profession and be open to new ideas". No argument there from anyone I suspect. I know it may seem like we keep beating a dead horse but I do agree that these discussions are beneficial in part, because it motivates us to continue thinking and questioning which forces us to reexamine our theories and beliefs.

  34. beauavery

    beauavery Welcome New Poster

    Dr. Kirby,

    First, thank you for the article. I would like to ask you, what significant changes to current orthotic design do you envision using Tissue Stress Theory, other than the ones you mentioned in your article? On the surface it appears that other modalities such as orthotic taping (?) and physical therapy are better suited, along with custom foot orthoses, for TST.

    Thank you in advance for your response.
  35. DrBob

    DrBob Active Member

    Are we interested in function? If so, how about we join the rest of the planet and talk in terms of displacement, velocity and acceleration? Just an crazy notion...
    Kind regards,
  36. efuller

    efuller MVP

    Now we are getting to the big existential question. Why a neutral position? What is it used for. Is the importance of neutral potion that it is a tool to decide whether a foot, or STJ, is pronated or supinated? Why do we need to decide if a foot/stj is pronated or supinated? Are we going to decide to push it toward the "normal"? Is the position of the STJ, within, its range of motion really the best criteria we can come up with to help us make the decision about which direction we want to push the STJ. There are feet that are laterally unstable that stand on the pronated side of neutral. Even though those feet are, by definition, pronated, they should be pushed toward pronation (unless the cause of instability is peroneal insufficiency.)

    If you want to call tissue stress an out growth of Root theory because we both choose to try to push the STJ in a direction based on the measurements that we take, then fine. However, we are using different measurements (STJ axis position in the transverse pane vs. position of the STJ within its range of motion. I think we are also using a different rationale for our choices. Although I'm not exactly sure what the rationale for pushing toward neutral position is. Is it because Neurtral is normal? Back to the circular definition. Why should neutral be normal?

    I agree that we should not look at the neutral position paradigm and take from it what is true and discard what is not true. We should make the effort to decide which is which.

    One of the interesting things about the McConail/Sarafian twisted plate idea was that they advocated that pronation of the STJ and inversion of the forefoot was a good thing because the plantar fascia became tighter and could act to make the arch more rigid. When I was a student, Paul Scherer did say that supination of the long axis and eversion of the rearfoot would increase tension in the plantar fascia. I think I will disagree with McConail/Sarafian because they did not recognize the possibility of overuse and damage to the tissue of the plantar fascia.

    Is the reason that you cannot see a complete theory in my writings the fact that I don't need a neutral position?

    Daryl, are you familiar with the measurement that I call maximum eversion height. (In stance ask a patient to evert and measure how high the lateral column gets off of the ground). Now, this measurement is my modification of John Weed's teachings. If you look at John Weed's prescription guidelines they could, most of the time, be boiled down to: don't attempt to evert the heel farther than it can go. I think this is a true concept. When John Weed taught prescription writing he taught about prescription writing for each foot type. Only the most rigorous student would take the time to compare one foot type with another. They mostly ended up with same prescription based on the rearfoot measurements and the heel bisection position. Another problem with the way John Weed taught prescription writing was the disassociation of the forefoot from the rearfoot. There were combinations of rearfoot to leg and forefoot to rearfoot measurements that would end up trying to evert the forefoot farther than it could go. It is much simpler to look at the net effect (maximum eversion height in stance) rather than to attempt the calculations from the leg, heel bisections and the forefoot to rearfoot measurements. John Weed's prescription writing protocol was made much more complicated than it needed to be by trying to incorporate neutral position into the equation. Which really doesn't make sense when the foot is not standing in neutral position. Daryl, again you could call what I do a modification of the Root paradigm. However, it is a modification that does not need to use neutral position. Is that a modification of neutral position theory, or a new theory?

    How does using a goniometer make you a better clinician? I can see if you measure a large difference in STJ ROM from one side to the other you should really suspect a tarsal coalition. However, as I pointed out above, the over reliance on goniometric measurements may force you to lose site of the intended goal. (Don't evert the foot farther than it can go. aka, in the surgical realm, thou shalt not varus) What other cllinical questions do goniometric measurements answer, that cannot be answered by direct observation?

    If you can't answer that then there is no need to come up with replacement goniometric measurements.

    Daryl, I again would like to thank you for taking the time to respond. I do appreciate your thoughtfulness.

  37. Rob Kidd

    Rob Kidd Well-Known Member

    My my, what a can of worms! I stand by all I have said about the invalidities of the subtalar neutral definition. And I usually avoid giving a clinical opinion as I do not really practice. However, in the comments, from Kevin I think, there was what I would regard as a sensible opinion. That is, whilst recognising that the definition is groundless in science, the examination of neutral is clinically a very useful tool.
  38. Rob Kidd

    Rob Kidd Well-Known Member

    Please remember, at the end of all this, I try hard not to express much in the manner of a clinical opinion - I leave that to you, Kevin, Simon and all the others that practice, Rob
  39. rdp1210

    rdp1210 Active Member

    Let me try to appeal to your sense of tissue stress with a little different approach. Let's suppose that I could find a position that the subtalar joint could be put in, in which the summation of tension on all the ligamentous structures was at a minimum, and in which the summation of the passive tension in all the tendons crossing the subtalar joint was also at a minimum? Would finding such a position interest you? Why or why not?

    I read with interest Kevin's use and description of neutral position. He may have used a few different words, but the concept of that "feel" of where that neutral position is reflects very close to what Mert Root taught me, and what I have tried to do and teach over the years. I have tried various descriptions of that feeling, with limited success with each modification of my description.

    I also noted that Dr. Kidd criticized me for using neutral position but accepted Dr. Kirby's use. I also note that he stated that he's not down in the 50-60 hr/week treating of patients, making decisions and solving all types of orthotic problems. It's nice to sit at the top of the trench, watching those struggle to continue to dig every inch of dirt at the bottom of the trench.

    No, the reason, I cannot see a complete theory is because you have only subtalar joint axis theory, and you have no hope of making a theory that can predict pathology. Your writings cannot lead to a preventative medicine paradigm. e.g. how does your theory predict hallux valgus? I may or may not agree with Root's theory of predicting hallux valgus, but at least he put something out there. Actually I partially agree with what he said, but he did not really explain why some pronated feet develop HAV and some do not. So his explanation was incomplete. As you know, I have written somewhat on this, including some additional ideas in the Albert book on how a better understanding the twisting plate and the location of the twisting could predict HAV.

    I wish I had more time this morning to comment on some of the complexities you mention, and some of the contradictions that appear on the surface. I need to become more familiar with your maximum eversion height, and I am not afraid to try and see if it of some use. As you noted in my brevity in the Albert book, I am interested in many more forefoot to rearfoot measurements.

    A goniometer makes me a much better clinician because I take the time to learn as much as I can about that particular patient. The summation of all the exams I have done has added up to a tremendous amount of learning experiences. When I find what appears to be contradictions, I look for reasons for those contradictions. As an example, I'm scratching my head on a patient I saw this week. Patient with laterally displaced STJA on one foot is pronating in stance, and the other foot, with normal STJA is supinating. There was symmetrical STJ motions and also FF-RF positions and motions. There are no neurological issues. I have to solve this problem. Don't know the answer. Do I just discard all STJ axis theory because of this contradiction? No! There is an answer, and I will solve it. I believe that there may some goniometric measurements that I'm not doing. I can say that I need to take a little more time and plot the movement of the STJ axis (see 1992) paper, which time I didn't take on the first exam. I also need to do a more detailed muscle testing exam (my initial exam didn't detect any asymmetries)

    Wish I had more time this morning to discuss why goniometry makes each person a better clinician. It looks like you're doing some type of goniometry measurements in clinical practice, maybe not the same ones I'm doing, but at least it's some attempt to bring quantification to biomechanics. Biomechanics without quantification becomes all 'bio', and no 'mechanics'. The more and better we can quantify, the more we are practicing bio+mechanics.

    Have a good day, and thank you for your comments,
  40. We do not need subtalar neutral to classify feet into "pronated" or "supinated" - see foot posture index (FPI-6) . A more interesting question might be: why do we need to classify feet into pronated and supinated? Prediction of pathology would seem key. While I'm aware that certain elements of the FPI have been shown to be predictive of anterior knee pain, I'm not aware of a whole host of pathologies being predicted by foot type classification in this way, nor any from the Root approach to classification with subtalar neutral.

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