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Challenging the foundations of the clinical model of foot function

Discussion in 'Biomechanics, Sports and Foot orthoses' started by NewsBot, Jan 31, 2017.

  1. NewsBot

    NewsBot The Admin that posts the news.

    Articles:
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    Challenging the foundations of the clinical model of foot function: further evidence that
    the Root model assessments fail to appropriately classify foot function

    Hannah L Jarvis, Christopher J Nester, Peter D Bowden, Richard K Jones
    JFAR 2017 (accepted publication)
     
  2. Admin2

    Admin2 Administrator Staff Member

  3. Craig Payne

    Craig Payne Moderator

    Articles:
    6
    Not mincing any words:
    "We recommend that clinicians stop using sub-talar neutral position during clinical assessments
    and stop assessing the non-weight bearing range of ankle dorsiflexion, first ray position and
    forefoot alignments and movement as a means of defining the associated foot deformities."
     
  4. Not at all, seems pretty clear what they concluded
     
  5. All I can say is that this paper is not news to me, nor many others, such as Simon and Craig.

    I wish I could get more excited about this paper but it is rather very old news. I first wrote about the problems with Subtalar Neutral Theory in August, September and October 1990 in Precision Intricast, Inc. Newsletters titled "Inaccuracies in Podiatric Biomechanics Dogma-Volume I, II and III" where I described many of the inaccuracies with Root Theory. That was over 26 years ago! In fact, many of us have been writing about the problems with Subtalar Neutral Theory over the years, both on the internet and in published papers.

    Studying symptomatic patients in this study would have made much more sense than studying asymptomatic subjects. And, by the way, for those of you who never heard Mert Root lecture, he never said that all people with "foot deformities" were symptomatic or that "foot deformities" always predicted symptoms. He did say that if someone with a "foot deformity" had symptoms, then you should treat them to reduce their "compensation" for their deformities to reduce their symptoms. In other words, I really don't think that if Mert Root were alive today that he would have been much surprised by the results of this study.

    Please remember everyone, Root's "normal foot and lower extremity" was an ideal (which he very clearly stated in his writings). Root's "normal and foot and lower extremity" did not mean "asymptomatic young subjects with no history of significant foot trauma or foot surgery". Root was very clear that many individuals with "abnormal" foot and lower extremity (i.e. non-ideal) structure, could easily be asymptomatic. In other words, "ideal" and "average" are two very different things.

    The bottom line is that better research will need to come along at a later date to better answer the many questions we have about the best way to evaluate and treat patients with foot orthoses. I don't treat asymptomatic people with foot orthoses. My question then is this: why study asymptomatic individuals to answer the question of whether certain evaluation techniques are worthwhile in treating symptomatic patients that have "non-ideal" foot and lower extremity structure and function???
     
  6. The issue is Root theory and similar are still being taught in schools not just in podiatry but Physio etc etc around the world. So until the Schools change what they teach we will be still having the same conversations as generation after generation still go looking for the normal foot and normal biomechancis
     
  7. Lee

    Lee Active Member

    Kevin & Mike - good morning from a drizzly north west UK. I read your points Kevin in your precision intricast compilations over 10 years ago when Chris Nester leant them to me in the building where this research took place. Thanks for compliling them - they were my favourite foot biomechanics resource at the time.

    My best guess as to why that population was studied - convenience. I don't think that podiatry schools in the UK still only teach Root biomechanics so the quoted assertion in the paper is probably a well formed, well researched but 20 years out of date piece of advice for UK educators that have already retired.

    Hannah will have had a certain time period and funding to do her PhD and used the guidance of her supervisors and available local kit (vicon/ qualysis, force plate, students and staff from the uni looking at the age range, etc...) to help form her research question and conduct her studies. It will have taken a while to complete and part of that delay will have contributed to the delay in publishing (I know this didn't take 20 years lol!). I'm guessing as I work elsewhere now, but this might just be the first and fundamental paper that comes out of her projects so she might build on some of the themes raised in later papers.

    I have students from Salford attend my clinics and they're not reciting Normal and Abnormal Function of the Foot to me. As you have said Kevin, it's still a worthy read and is probably misquoted (most likely by people who never read it in the first place). Historically, the podiatry school at Salford sat in a different building to the gait lab that Chris used. Things have changed a bit over recent years so the undergraduate students get a bit more access to gait labs, etc...

    Have a good day,
    Lee Murphy
     
  8. Lee:

    I realize that the study was probably done this way since it was easier to find 100 asymptomatic healthy relatively young (18-45 y/o) adults at a university than 100 symptomatic older adults. However, to study asymptomatic people who are young and state that the Root measurement don't predict gait function in these young people and then demand that clinicians not use methods which may classify foot structural abnormalities to evaluate foot structure and function is, in my opinion, unreasonable.

    As previously stated, I was probably the first one in the USA, and one of the first worldwide, to openly criticize the beliefs of Root et al that I was taught in podiatry school from 1979-1983. In fact, I was challenging my podiatry students on Root dogma back in my Biomechanics Fellowship from 1984-1985 when I became more aware of the importance of subtalar joint (STJ) axis location on the kinetics of the foot and lower extremity . That does not mean that I feel that Root's life-long work is totally without merit since I still use some of the evaluation methods he taught in my own patients. I also still find them to be useful to help me to better understand the structure of the segments of the foot and their functional influence on each other.

    Do I measure STJ neutral still? No. I don't see any purpose for this specific measurement.

    Do I still measure ankle joint range of motion in a non-weightbearing fashion? Yes. I still measure ankle joint dorsiflexion on the table since I can control the amount of force (and the amount of ankle joint dorsiflexion moment) being applied to relatively accurately determine passive resistance of the ankle to dorsiflexion motion. Their study did not invalidate this measure as a source of potential abnormal kinetics to the foot and lower extremity (they only measured kinematics) over time so why did they recommend clinicians not use it?

    I still measure first ray range of motion, and especially am interested in first ray motion on my bunion surgery patients since I know of no better way to assess the passive function of the first ray relative to the lesser metatarsals and the potential for my surgery to create a transfer metatarsalgia to the lesser metatarsals. Their study did not invalidate this measure as a source of potential abnormal kinetics to the foot and lower extremity (they only measured kinematics) over time so why did they recommend clinicians not use it?

    Finally, I still measure forefoot to rearfoot alignment since I do feel this strongly affects the loads placed on the metatarsal heads and STJ moments (i.e. foot kinetics). Again, their study did not invalidate this measure as a source of potential abnormal kinetics to the foot and lower extremity over time so why did they recommend clinicians not use it?

    My conclusion, this was a good study that would have been much more useful 20 years ago than it is now. We now know that forces and moments cause injury and know that motion, which these researchers only studied, does not necessarily cause or predict injury. We know that foot orthoses primarily affects forces and moments and are very good at treating injury but are not good at changing kinematics of gait. However, this paper only studied the motion of asymptomatic healthy people, and did not study their plantar pressures, external joint moments, internal joint moments, tendon or ligament forces, central nervous system efferent activity to lower extremity muscles or joint loading forces, all measures which may produce injury.

    Why then, with a study that only looked at kinematics of healthy people, and did not study kinetics of injured people, would we change the way we do things for people with injuries and that has worked so well for many clinicians over the decades? I can think of much better ways to make a point of getting rid of some of the outdated Root dogma and going forward with a Tissue Stress Approach (Fuller EA, Kirby KA: Subtalar joint equilibrium and tissue stress approach to biomechanical therapy of the foot and lower extremity. In Albert SF, Curran SA (eds):
    Biomechanics of the Lower Extremity: Theory and Practice, Volume 1. Bipedmed, LLC, Denver, 2013, pp. 205-264.; Kirby KA: Prescribing orthoses: Has tissue stress theory supplanted Root theory? Podiatry Today, 34(4):36-44, 2015).

    All in all, this paper was a well-done study, that only studied the kinematics of asymptomatic, healthy, young adults, and not the kinetics of injured people. More and better kinetics research on injured vs injured people will be necessary to best answer these important research questions of what evaluation methods best predict the injury patterns we see in our patients.
     
  9. Lawrence Bevan

    Lawrence Bevan Active Member

    Kevin

    Sorry to take this off topic but seeing as you mentioned it, please can you explain how you assess the 1st ray prior to bunion surgery and what do you look for? does it influence how you manage the patient?

    thank you

    L
     
  10. Jeff Root

    Jeff Root Well-Known Member

    The following conclusion is from Challenging the foundations of the clinical model of foot function: further evidence that 2 the Root model assessments fail to appropriately classify foot function
    "Conclusions 38
    Taken as part of a wider body of evidence, the results of this study have profound 39 implications for clinical foot health practice. We believe that the assessment protocol 40 advocated by the Root model is no longer a suitable basis for professional practice. We 41 recommend that clinicians stop using sub-talar neutral position during clinical assessments 42 3 and stop assessing the non-weight bearing range of ankle dorsiflexion, first ray position and 43 forefoot alignments and movement as a means of defining the associated foot deformities. 44 The results question the relevance of the Root assessments in the prescription of foot 45 orthoses".

    Profound implications indeed! Are they (or you) willing to eliminate all of the following terms from your vocabulary because they derive their meaning from Root’s STJ neutral position based classification system?: forefoot varus, forefoot valgus, rearfoot varus, rearfoot valgus, a rectus/vertical/perpendicular heel or rearfoot, forefoot supinatus, plantarflexed 1st met/ray, metatarsus primus elevatus, etc. I believe their conclusion ignores the importance of these terms in modern day foot surgery as much if not more than it does their importance in foot orthotic therapy. What alternative do the authors propose we use to help describe the function, position and structure of the foot?
     
  11. Lawrence:

    I look for first ray range of motion and relative stiffness of the first ray clinically during examination of the patient before bunion surgery. I also look at AP radiographs to determine the length of the 1st relative to 2nd metatarsal. I check also for any skin lesions and quality of skin plantar to the 1st and 2nd metatarsal heads to determine whether the skin plantar to either is showing signs of over-loading or under-loading. These parameters generally give me a good indication of how my bunion osteotomy may affect the loading of the other lesser metatarsals.

    Hope this helps.
     
  12. Trevor Prior

    Trevor Prior Active Member

    Kevin has made some really good points of clarification, particularly as to how he uses certain structural positions to inform him of the likely kinetic outcomes.

    I think one of the biggest issues for education of the subject is confusion. Whilst those that have studied all of the paradigms and have many years of experience to help inform their practice, are able to combine the information, we are yet to pull all of this together into a succinct process for assessment and management. I tend to find colleagues hang their hat on an approach, usually depending upon who has influenced their practice.

    To my mind, understanding how various structural alignments of the whole lower limb have the ability to influence load on the foot, how this may be modified by muscle strength, flexibility and neuromotor control, that the foot does not function around a magical position and that the degree and direction of motion, and thus response to orthoses will be highly variable between individuals is a good start.

    If one ignores the underlying structure (the risk of throwing all of this out alongside the subtalar neutral theory) then one reduces the ability to try and determine how an intervention may affect function and, more importantly, how we may modify if an intervention has a negative affect. This fully accepts the limitation and lack of evidence we have for prescription protocols and individual response.

    Interestingly, I assessed someone who is a fitness trainer yesterday and came with her orthoses. The difference in her pelvic drop (L:R) was 1.5 and 2 degrees walking and running respectively. With her orthoses, this differential increased to 4 and 6 degrees respectively. In other words, they made it worse. How much can an individual tolerate, we do not know the answer to that question but what motion changes where will vary greatly and be determined by all of the factors that contribute to function.

    Ian made a great point in a very good lecture yesterday regarding statistics. Had I observed a second patient whose change had been reversed (in other words, the results were the same but changed int he opposite direction), the average would show no change, clearly not the case.

    I have no doubt we will see more information from this PhD and I look forward to it so that it can inform further. For the record, I too look at forefoot to rearfoot for the same reasons as Kevin. I also look at 1st ray but tend to assess ankle motion weightbearing these days. It is also nice to see we are considering the same factors for our HAV patients. I think it is worth noting that 1st ray stability can improve just by correcting the deformity.

    Trevor
     
  13. efuller

    efuller MVP



    We have been having the the throw the baby out with the bath water discussion for a long time. There are some very useful concepts in the Root paradigm. I don't think that forefoot to rearfoot measurement can be done accurately. However, I have learned from Jeff, that there really is something to the extremes of this measurement. The partially compensated varus foot with a high lateral load is a real thing. However, using the non weight bearing measurements to figure out if you have a partially compensated varus is an exercise in futility. John Weed was on the right track when he talked about assessing load in stance. You can apply the broad ideas without getting caught up in the measurements.

    However, I really agree with the last line quoted above. If you look at the history of the development of the orthotic manufacturing process proposed by Root, it is hard to disagree that the measurements proposed should not be used in writing an orthotic prescription.

    It really seems that Root et al found something that worked and then worked backwards to try and make the paradigm fit what worked. If you followed the paradigm you would cast the foot in neutral position and balance the cast in NCSP to reach the ideal. However, they went with what worked which is an orthotic that had a higher arch height (neutral position) than standing arch height and balanced it to vertical. MASS technique is just another refrain on making the arch higher. Through experimentation they added the medial expansion plaster to make the device more comfortable. It is really hard to pin down Root disciples on how an orthotic works. They might say: It places the foot in neutral position. No, it moves the foot toward neutral position. No it supports the forefoot to rearfoot deformity. etc. As one criticizes these various positions the goal posts keep moving.

    It is important to know what to keep and what to discard. The debate is still important even though we have been around the stump a few times.


    The teachings of John Weed made me really respect the idea of transfer lesions. Understanding how altering one metatarsal will affect the loads on the other metatarsals is very important.

    Eric
     
  14. Jeff Root

    Jeff Root Well-Known Member

    To highlight my point that Nester et. al. are out of touch with the needs of modern day foot and ankle orthopedics, let’s look at one chapter in McGlamry’s Comprehensive Text Book of Foot and Ankle Surgery, 4th edition which was published in 2013. Chapter 42, Pes Cavus Surgery, first involves a discussion on how to differentiate cavus (plantarflexed foot) from equinus (plantarflexed ankle). “Clinical and radiographic examinations are important to differential the location, dominant plane, and severity of the deformity”. Some cut: “An equinus deformity will frequently benefit from heel cord lengthening, enabling the heel to contact the ground. A pes cavus deformity normally does not benefit from heel cord lengthening and in fact can be made more severe, since the heel cord is resisting further contracture within the high-arched foot”.

    Some cut: “Although pes cavus is defined as a sagittal plane deformity, frontal and transverse plane deformities are commonly associated with the high-arched foot, and require individual assessment and consideration from a surgical standpoint. Two common frontal plane deformities are encountered in patients with a pes cavus foot type: forefoot valgus, or a plantarflexed first ray, (fig 42.9) and a varus or inverted heel”. Compensation for frontal plane deformities relies on available range of motion of adjacent joints. The valgus forefoot compensates primarily in the hindfoot through the subtalar and midtarsal joints, and this leads to a varus (rigid) or inverted (flexible) heel.

    Patients with frontal plane deformities are assessed with a Coleman Block test prior to surgery to determine whether or not the hindfoot has the ability to pronate if the effect of the plantarflexed 1st ray is eliminated. If the hindfoot is able to realign to a vertical heel position when the 1st ray is off-weighted, then an elevating osteotomy of the 1st metatarsal can be used to correct the hindfoot inversion that occurs due to the effect of the forefoot on the rearfoot”.

    Some cut: “If the heel alignment is fixed in rigid varus, then an elevating osteotomy of the first metatarsal will be insufficient to correct the varus alignment of the heel. In these instances, a valgus-realigning osteotomy of the calcaneus (Dwyer osteotomy) is used to reposition the calcaneal varus to a normal vertical alignment”.

    As Root et. al. pointed out in their first book, “Biomechanical terminology must become orthopedic terminology, for the future development of clinical understanding and communication relating to the lower extremity”. Some cut: The terms, as defined by the authors in this manual, are in common orthopedic usage, but each term has been provided a strict scientific definition”.

    Nester et.al. continue to fail to recognize and appreciate the fact that biomechanics is not limited to orthotics and the other forms of non-surgical patient care. Lower extremity biomechanical terminology, theories and techniques must be applicable in a wide variety of disciplines and for a wide range of applications, including surgery. In this very recent edition of McGlamry’s Comprehensive Text Book of Foot and Ankle Surgery, one of the most highly respected modern day publications on foot and ankle surgery, we can see how central some of Root’s more succinctly defined terms are to the surgeon. We cannot use terms such as forefoot valgus without having a common definition and a common understanding of how forefoot valgus is determined clinically. In this chapter we can clearly see how important having a structural classification system and techniques to assess ankle ROM are to the surgeon.

    Are Root’s techniques perfect? Certainly not. But are we better off with them in spite of their imperfections and limitations? I certainly believe we are, especially when we look at the broader application of these techniques and theories. So I cannot agree with Nester et. al. in their conclusion that “We recommend that clinicians stop using sub-talar neutral position during clinical assessments and stop assessing the non-weight bearing range of ankle dorsiflexion, first ray position and forefoot alignments and movement as a means of defining the associated foot deformities”.

    I have selected just one small section of this chapter to help illustrate my point. This book and others, including Kevin Kirby’s books, are filled with references to these terms which come to us as a result of Root’s subtalar neutral classification system. If and until there is a valid alternative, these terms and techniques will continue to be in use despite the impractical recommendation of Nester et. al.
     
  15. In my fourth Precision Intricast Book, including 141 pages and 59 newsletter articles, I only reference the term "forefoot varus" twice: in regards to previous research on patellofemoral pain syndrome and in regards to the shape of a forefoot extension. I also referenced "subtalar joint neutral" three times. However, the term "forefoot plantarflexion moment" was mentioned 17 times, "rotational equilibrium" was mentioned 57 times, and "supination moment" was mentioned 55 times (Kirby KA: Foot and Lower Extremity Biomechanics IV: Precision Intricast Newsletters, 2009-2013. Precision Intricast, Inc., Payson, AZ, 2014).

    My four books, all of which have now been translated into Spanish language editions, discuss newer ideas and concepts, more consistent with the terminology used within the International Biomechanics Community. These books were written for the purpose of moving our profession forward away from poorly-supported "subtalar joint neutral" concepts that, for many years, were taught dogmatically within podiatric medical schools both here in the USA, and abroad.

    Thankfully, most modern and well-informed podiatrists , and other foot-health clinicians, are moving away from using "forefoot to rearfoot deformity", "subtalar joint neutral", "rearfoot varus" and "rearfoot valgus" and "neutral calcaneal stance position" to prescribe foot orthoses for their patients. Instead, most progressive clinicians that I know are using more of a tissue-stress approach to determine how best to design their patient's custom foot orthoses.

    It will take time to change old notions and push forward with better ideas, but it will be well worth the struggle in order to ensure better therapeutic outcomes for our patients.
     
  16. Jeff Root

    Jeff Root Well-Known Member

    How many times are the terms forefoot plantarflexion moment, rotational equilibrium and supination moment mentioned in McGlamry's two volume, 1928 page book Foot and Ankle Surgery or are they even mentioned at all? This just further emphasizes my point about the disconnect.
     
  17. I am trying to push foot and lower extremity biomechanics and foot orthosis forward for podiatry and don't mind becoming separate and distinct from those who don't have the time nor inclination to stay current with the latest research or biomechanical priniciples. In other words, it probably won't be until the 2030 update to McGlamry's textbook they will finally start using more modern biomechanics terminology. ...;)
     
  18. Trevor Prior

    Trevor Prior Active Member

    Jeff
    In my opinion, stating that Nester et al are out of touch is not appropriate or indeed accurate. They have systematically analysed the process and identified, in line with other research, that much of the underlying proposed theory does not correlate to dynamic function and therefore question the predictive nature of the process.

    They have been clear that they have identified the kinematics and, in this paper, have not analysed kinetics – they may have done this and be due for publication.

    The predictive nature of assessment is more difficult to justify as this would require a longitudinal study but the underlying basis of structure alone not predicting function is clear.

    I have the McGlamry books and they are very good but will have been written somewhat before the publication date, with many of the clinicians likely to have been familiar with the Root et al paradigm. They are quoting the common interpretation of practice rather than the results of their research and thus, the publication alone does not justify the principles. In many ways, this is why the principles remain around for so long as they are simply repeated in text after text.

    Like Kevin, I perform surgery and we cut and move things and therefore have to have some form of criteria. Generally, we put things that are in a bad position into a less bad position and have some justification in doing so. I personally, have some concerns regarding the approach taken for flat foot reconstruction for instance as it can ignore contributing factors. However, when something is sufficiently pathological to require surgery, patients often respond. Interestingly, if we take most forefoot surgery, generally 80% of patients improve, irrespective of what you do assuming you do it well and it is logical. Rather like giving orthoses, many respond with something, even if it is off the shelf and bought online.

    I agree with Kevin that it will take the next edition to start to introduce new terminology but this is where I believe we should be considering how to influence discussions. We do still look at structural positions because they do contribute to how forces are applied but we do not rely on the STJ neutral position and base everything around a kinematic model that is not supported by a wealth of data.

    If we can define a set of terminology that allows us to have descriptive terms for the varying structural alignments we see in clinic, that help define how these may affect the forces acting on the lower limb, then we will have the basis for a common language and, more importantly, a basis for education and further research.

    Trevor
     
  19. cpoc103

    cpoc103 Active Member

    Mike this is my sentiments exactly, and have been saying this for many years.


    I was also very glad to read that some of the worlds top podiatric biomechanists are still using some of the root measurements, as Kevin stated, I still use a lot of these measures so I can identify and understand the moments and forces.
    For a while I was worried I was a bit outdated, even despite the fact that I am seeing very good results clinically. Phew
    Col
     
    Last edited: Feb 8, 2017
  20. Jeff Root

    Jeff Root Well-Known Member

    Trevor, what I said was that I believe that Nester et. al. are out of touch with the needs of modern day foot and ankle orthopedics. I don’t believe that foot and ankle surgeons can immediately stop using all of Root’s neutral STJ examination and classification system and techniques as recommended. Do you agree with their conclusion that “We recommend that clinicians stop using sub-talar neutral position during clinical assessments and stop assessing the non-weight bearing range of ankle dorsiflexion, first ray position and forefoot alignments and movement as a means of defining the associated foot deformities.“ and if so, why do you agree with them? In addition, if you agree with Nester then what do you suggest that foot and ankle surgeons use in place of all of the Root based techniques?

    If you agree with Nester then you no longer have the concept of a neutral STJ position. And the terms ff varus and valgus, rf varus and valgus are no longer are determined with the STJ in the neutral position and with the MTJ fully pronated as described by Root. Hence, we revert to the pre Root days where these terms were used without any concise anatomical definition. If Nester et.al. actually expect foot and ankle surgeons/orthopedists to abandon these and all of Root’s other work then I do believe it is fair to state that they are out of touch with the needs of this community of medical specialists.

    I believe it is out of touch to suggest that foot surgeons stop examining the open chain ROM of the ankle or 1st ray when contemplating whether surgery is indicated. Would you do an osteotomy of the 1st without first determining if the patient had a metatarsus primus elevates, a plantarflexed 1st ray or a “normal” 1st ray position and ROM? Would you base surgery solely on a dynamic examination? How else would the surgeon asses the need for surgery on this structure? The same principle holds true for the ankle. Would you do a TAL without examining the open chain range of dorsiflexion of the ankle and without measuring and documenting the limitation of motion, and determining whether the limitation is osseous or soft tissue in nature? If they are not out of touch, then please tell me what I have missed that makes these and many other assessments no longer necessary?
     
  21. Jeff:

    These are all good points you make and are the reason we need to not "throw the baby out with the bathwater". All of us who are interested in improving the therapeutic outcomes of our patients, including yourself Jeff, Trevor and the others in this discussion, need to forget about our differences, take a step back and reevaluate what we have good evidence for and what we don't have good evidence for. I don't think it is in our own best interests, nor the interests of our patients, to totally throw out classical techniques and terminology unless evidence-based replacement techniques and terminologies become apparent that are definitely better than the older ones.

    In other words, I don't think we are at that point where we can "throw out the subtalar neutral bathwater" since alterations in structure will produce alterations in kinetics...that is provable with modelling and free body diagrams and even finite element analysis. The research is already there to back up this long-accepted idea that structure affects kinetics. However, we don't have good research that I know of that supports the idea small changes in foot and lower extremity structure affect the kinematics of gait.

    In order to do that, we will first need to know more about central nervous system regulation of gait. And, for that, we are in our infancy of understanding the central nervous system and its efferent motor control systems in each individual. Without this necessary kinetics research and only studying kinematics, we are only touching the surface of what causes pathological tissue loads within the structural components of the foot and lower extremity that produce the injuries we see daily in our clinics.

    Many of us have been analyzing the faults with the subtalar joint neutral approach to foot orthosis therapy, suggesting improvements and/or replacement of terminology, evaluation techniques, and orthosis prescription techniques and even suggesting new theories of foot function and mechanically-based foot orthosis treatment over the past few decades. We must now wait for researchers tell us if our newer ideas, techniques and orthosis prescription methods are actually as useful as we think they are. In the meantime, until that research is done, every clinician needs to be aware of how the evidence and theories and techniques are changing so they can make the best informed choice as to how their patients should be treated with all the different therapeutic options available to us.

    In regards to Dr. Chris Nester, he has done more for podiatry with his research and theory than nearly any research-podiatrist in the world. I have a huge amount of respect for him and consider him a great friend and respected colleague. When he writes something, I read very carefully because he is a very intelligent man. However, I don't agree completely with him on everything, and, in this instance, I think him and his colleagues on this recent paper have "jumped the gun" regarding abandonment of classic examination techniques without better kinetic research to support their opinions.

    By the way, best discussion on Podiatry Arena in the past year! Thanks everyone!!
     
  22. Jeff Root

    Jeff Root Well-Known Member

    Kevin, I can't disagree with anything you said!
     
  23. Trevor Prior

    Trevor Prior Active Member

    Firstly, I think Kevin’s last comments are spot-on.

    Jeff

    In response to your comments, firstly they evaluated the relationship of these concepts to the kinematics of normal subjects. Whilst I am not suggesting that we simply ignore this for pathological patients, we are looking at a different subset who have clear structural abnormality that needs addressing surgically when we are assessing the surgical patient. We therefore need some basis for assessment.

    I will take up a few of your points and simply give my spin/thoughts albeit that this is simply what they are, my interpretation.

    Re: Subtalar joint neutral, it is not something I assess any longer but I will make a subjective assessment of the degree and direction of rear foot motion, the degree of tibial varum and the relaxed stance rear foot position (which includes lateral translation in relation to the lower leg).

    I do review forefoot to rear foot position but I do not worry myself to much about the exact position of the rear foot. I am more interested regarding the relative degree of alignment, the degree of symmetry with the other limb and the degree of midfoot mobility.

    With regards ankle joint dorsiflexion, I tend to use more weight-bearing tests generally but acknowledge that there will be a subjective non-weightbearing assessment in the surgical patients with the knee both extended and flexed. This is in part due to habit and feeling comfortable after many years of performing the examination. The important thing here is to acknowledge that the dorsiflexion can occur throughout the foot and that their work indicates that the non-weightbearing assessment (much like first MTPJ dorsiflexion) does not translate to dynamic function. There may be better and more objective ways of assessing this motion. However, when a flat foot is corrected, it can identify a greater degree of equinus than expected and clearly, it is not possible to perform an intraoperative weightbearing assessment.

    I do not wish to start a new thread on first ray position but this is a particular area of interest of mine. Although I no longer measure, I have measured thousands using the Kilmartin sagittal ranger. I can advise you that I cannot recall ever having measured a first ray with more dorsiflexion than plantar flexion in a non-pathological first MTPJ and even then it is less common. In addition, my normal finding is that the first ray has more plantar flexion than dorsiflexion in relation to the lesser metatarsals. Of course this makes the assumption that the measure is repeatable and I am accurate. I personally question metatarsus primus elevatus as this is a diagnosis primarily made on x-ray and is usually a compensated position rather than an underlying deformity (my interpretation and opinion). There are of course cases when there is instability at the metatarso-cuneiform joint and these will have specific findings/measurements on x-ray.

    Now I fully except you may have a different opinion and I have simply laid this out to show how there can be differences of opinion and that we need to review what evidence we do have and be realistic in our application of that information. That does not mean that I do not think for instance that a more inverted forefoot may be more of an issue surgically (whether I be assessing HAV or a flat foot), but the way in which this contributes to foot loading and thus surgical outcome is less clear cut. What i do not want to do is the patient with a foot that is more inverted - you will be familiar with the surgical adage of 'thou shalt not varus'.

    Surgically, our primary aim is to provide a more stable, less abnormal foot structure in the hope that this will resolve symptoms. The effect that this has more proximally has not been sufficiently studied and we might find that if we have more accurate and objective ways of assessing normal and abnormal function, we may be able to refine surgical techniques and improve our outcomes (or at least have more consistent outcomes) surgically. Until then, I will use a balance of the assessment techniques I have available to me in combination with my experience to try and determine the best outcome for the patient.

    I realise that each of the comments above could start a whole new thread and that is not my aim, but you asked what I assess and explaining was the only way.

    Trevor
     
  24. Jeff Root

    Jeff Root Well-Known Member

    Trevor, I think we have a lot of common ground. You said:
    This assumes you (we) have some normal value or standard. Root attempted to create that. Root expected his theories and classification system to be improved, updated, changed or even replaced with time. In fact he was know to complain back in the 1980's and later because more had not changed and he expressed the fact that he was disappointed because research and progress were so slow. I think we need to recognize the benefits and limitations and strengths and weaknesses of Root's neutral position classification system and I just wish that Nester et. al. had acknowledged that, rather than to suggest that clinicians abandon it entirely. Remember, Root's primary objective was for it to be a system of examination and comparison more than anything else and he stated in volume 1 that "Only the clinician can determine when the variance is sufficiently great to produce pathology". He did not suggest that variances from his normal/ideal were necessarily pathological.
     
  25. Jeff Root

    Jeff Root Well-Known Member

    In the above referenced quote from McGlamry's book, they use the Coleman Block test to determine if the rearfoot has a sufficient range of motion to enable the heel to pronate back to vertical. The Coleman Block test is very consistent with Root's theory of compensation for a congenital plantarflexed 1st ray. Root theorized that a plantarflexed 1st ray would be compensated by 1st ray dorsiflexion and, if the ROM of the 1st ray was insufficient, then by inversion (supination) of the forefoot. If the 1st ray and the MTJ were unable to compensate for the everted forefoot, then the rearfoot would invert via STJ supination in order to bring the lateral aspect of the forefoot in contact with the supporting surface. In other words, rearfoot inversion is a compensation for certain everted forefoot "deformities". The Coleman Block test demonstrates that an everted forefoot can cause, or can cause an increase in rearfoot inversion/supination. We also know that a functional orthosis that incorporates valgus forefoot support can also reduce rearfoot supination (compensation) in the same manner as did the Coleman Block test. If we did not cast the STJ in or near the neutral position and if we did not pronate the MTJ during casting, our orthosis would not reflect the full degree of forefoot eversion and the resulting orthosis would not provide as much valgus support in the forefoot. The Coleman Block test shows us that we need to support the forefoot in an everted position to reduce the supination moments that are causing the rearfoot to invert in this foot type, or we need to reduce the degree of forefoot eversion surgically to reduce or eliminate the STJ supination moments. This is an example of how biomechanical theories and techniques need to be applicable in both non-surgical and surgical practice.
     
  26. I think this is where much of the issue is the Normal abnormal bit and using that to define/determine if it will produce pathology, I know Kevin will disagree with me he has before others too, but N = 1 there is only trends to Normalcy and if we use them a true Normal we are not treating the individual using best practice. The other issue when talking Root mechanics I bet there are only a handful of people using Root mechanics with the level of understanding of you Jeff ( Kevin, Eric sure, Simon Spooner etc ) the rest are using some sort of bastardized version which focuses on comparisons to " Normal " and abnormal, where abnormal = Pathology and needs to be treated ( this is of no fault of the authors or yourself Jeff but the way it is)

    So while the authors Jarvis, Nester et al did not mince words I see the reason why they were written.
     
  27. I will need to sit down and write an article sometime on my opinions as to what the pros and cons were of the contributions of Mert Root, John Weed and Bill Orien to podiatric biomechanics. Since I am really the only active lecturer on foot and lower extremity biomechanics that I know of in the world (Rich Blake doesn't lecture much anymore, Ron Valmassy hasn't lectured in years, Chis Smith may lecture occasionally) who actually got to know Mert Root and John Weed and taught their theories at one time, I suppose I owe this to the profession and to the memory of Mert and John.

    One of the big problems that Dr. Root had was that, at the peak of his career, he had some major health issues which forced him to leave being the Chairman of the Biomechanics Department at CCPM (Tom Sgarlato took over Root's position as Chairman of CCPM Biomechanics Department) and leave private practice (David Francis took over his practice with John Weed). I believe this greatly affected Dr. Root's ability to continue in his fine work from his podiatric career.

    When I interacted with Dr. Root as a podiatry student, Biomechanics Fellow and young podiatrist at his many seminars, I found him to be extremely intelligent, very serious about his work, but somewhat dogmatic about his beliefs. Of course, he was 35 years older than me, and no one knew who I was back then, other than my fellow students, residents and faculty members at CCPM. I don't really think Dr. Root knew what to do with me and my many questions about his ideas so he probably interacted with me differently than he would with others who he had known for many years. I never felt he disliked me, but I was more a "rabble-rouser" by questioning the accuracy of the many measurements he wanted us to do to use "his system" of making custom foot orthoses for patients. I did see him change his opinion on a few occasions, but, by the time I go to know him, he was already 60+ years old and not of good health. In other words, I think he was just trying to hang on and continue his teaching as much as he could when I first met him and saw him lecture and didn't want to be bothered by a young up-start such as myself.

    That being said, I think Dr. Root's contributions were huge for the podiatry profession, but that, possibly because of his personality or his health at the time I was attending his lectures, he was not ready nor willing to hear and consider challenges to his theories in a way that stimulated discussion and change in the latter half of the 1980's (when I was starting to lecture and publish).


    Alternatively, I found Dr. John Weed and Dr. Ron Valmassy were quite different than Dr. Root since Drs. Weed and Valmassy always thoughtfully considered my ideas and questions very carefully to help try to guide me along a path that may be helpful for me and our patients. However, I also spent much more time interacting with Drs. Weed and Valmassy than I ever did with Dr. Root. Therefore, Drs. Weed and Valmassy knew me much better since they were my professors in class and my teachers in the biomechanics clinic at CCPM.

    Students of history will always appreciate that there are always more than two sides to every accounting of historical "facts". I just hope that those who never got to hear Dr. Root lecture, or speak with him, think that he was out to make a name for himself or that he was near-sighted of the facts around him. On the contrary, Dr. Root was a great man that was ahead of his time and that paved the way for younger individuals like myself to try and improve on the methods he proposed for treatment of mechanically-based pathologies of the foot and lower extremity.

     
  28. Jeff Root

    Jeff Root Well-Known Member

    Kevin,
    Looking back on it, I think page 1 of Biomechanical Examination of the Foot (copied below) is somewhat prophetic. Here we are today, forty-six years later, still dealing with the same issues. One of the most critical issue is that we cannot have meaningful communication without clear and consistent terminology. My point is a simple one; the terminology described by Root et. al., which is based in part on the neutral position classification system, improves our ability to communicate within podiatry as well as with and within other disciplines. I believe that the conclusions of Nester et. al. ignore this need. I have heard from Podiatry Labs in Australia who are very concerned about the potential adverse impacts of the Nester et. al. recommendation. Here is what Root et. al. had to say on the subject and they considered it important enough to make it page one:

    Biomechanical Examination of the Foot, page 1:
    INTRODUCTION TO TERMINOLOGY
    Biomechanics is a science. As a science, its terminology must be exact and consistent.

    Orthopedics is a medical discipline. Its basis, in the future, will be biomechanics. Former orthopedic terminology, as applied to the lower extremity, is not exact and, therefore, inconsistent.

    Biomechanical terminology must become orthopedic terminology, for the future development of clinical understanding and communication relating to the lower extremity.

    To understand the foot, one must have terms which accurately describe motion of one part to another, and of a part to the floor. Furthermore, structural abnormalities place certain parts in positions which cannot be attained by any motion in a normal foot. Therefore, three sets of terms are necessary. They are:
    1. Terms to describe motion.
    2. Terms to describe position.
    3. Terms to describe bone deformity.

    The terms, as defined by the authors in this manual, are in common orthopedic usage, but each term has been provided a strict scientific definition.

    Advancement of clinical treatment and knowledge of the foot have been seriously impaired by a lack of specifically defined and commonly accepted terminology. That inter-professional communication barrier has been successfully broken by those practitioners who have learned .and applied the definition of terms described in this chapter. Categorically, it can be stated that no science can be understood or applied without concise understanding of terminology applicable to that science. Biomechanics cannot be understood, or used as a basis of practice, until you speak the language!
     
  29. I would add to the list the following for today's podiatrist:

    4. Terms to describe forces.
    5. Terms to describe rotational forces (i.e. moments).
    6. Terms to describe external versus internal forces and moments acting on the tissues of the lower extremity.
    7. Terms to describe the stress acting on the tissues of the lower extremity
    8. Terms to describe the strain acting on the tissues of the lower extremity.
    9. Terms to describe the time-dependent viscoelastic characteristics of the tissues of the foot and lower extremity.
    10. Terms to describe the elastic modulus of the tissues of the lower extremity.
    11. Terms to describe the sensory (i.e. afferent) input and motor control (i.e. efferent) output of the muscles of the lower extremity and their interactions with various changes in loading patterns on the plantar foot.

    I could go on. That is the difference between foot and lower extremity biomechanics within the international biomechanics community between 1971 and 2017. Foot and lower extremity biomechanics is, now, much more than "motion", "position" and "bone deformity".
     
  30. drhunt1

    drhunt1 Well-Known Member

    What a bunch of garbage! Kevin...seriously...do you actually believe the stuff you write? First, you wrote a "book" compiling non-peer reviewed articles...and pawn it off as science? Gimmee a break! Second...you write a fallacious argument, in your first sentence, 3rd paragraph. "Thankfully, most well-informed podiatrists...(followed by extreme hubris, detritus, balderdash and poppycock). Tell us, Kevin...how many orthotics Labs use TST on their Rx forms? Answer=zero. Not one. KLM is the world's largest manufacturer of orthotics...would you care to see their form?

    http://www.klmlabs.com/PDF'S/klm_order_form.pdf

    Can you or Eric Fuller please point out where on that Rx form where TST calculations are asked for? While I agree that forefoot to rear foot calculations aren't that helpful, it wasn't until my article was written/published that forefoot to ground calculations were even discussed, as far as I know. NCSP is extremely helpful...and I contend if a "Progressive clinician" is not looking at it, they're not very good at resolving problems.

    Which brings up the question I asked you, as well as others here, multiple times...what clinical maladies has TST ever solved? In re to another post of yours above...how many bunionectomies do you actually perform every year? According to tech reps that work/have worked your area...not very many...they tell me, in fact...very few. Yet you responded like you're a highly skilled surgeon that performs them every week...eh?

    Finally...if what you wrote was even remotely true, then why was your conference at Samuel Merritt/CCPM so lightly attended...you know...the one with you and McPoil lecturing? Maybe it's because you've beaten the TST into the ground and no one's buying it anymore....because it doesn't solve anything. Correct me if I'm wrong...but I doubt it.
     
  31. Trevor Prior

    Trevor Prior Active Member

    Matthew

    I do not wish to become involved in any personal arguments, suffice is to say the tone of your email was somewhat rude and, in my opinion, went past professional debate/disagreement.

    With regard your comments about laboratory prescriptions and tissue stress, in my opinion, there are only so many ways in which one can reduce tissue stress and most of the common factors we use in prescriptions suit that purpose: The shape of the orthoses, the relative flexibility of the materials and where we choose to place additional materials/wedges to alter the load on the foot for example. Thus, one can use all of these factors to address tissue stress if one is taking that approach.

    Neutral calcaneal stance position alone is a somewhat redundant concept when it comes to describing the function of the foot. This has been shown by the research. However, the degree of tibial varum is, in my opinion, relevant as this will alter the relative loading of the foot with the degree of motion available determining the amount of compensation and thus the relative load beneath the foot. Thus, a patient with a larger degree of tibial varum will have a tendency to load the lateral border of the foot thus increased pronation moments. In a less mobile foot, there will be less compensation and relatively increased lateral load/reduced ability to compensate, compared to a more mobile foot. These 2 foot types are likely to show altered loading patterns.

    One does not need neutral calcaneal stance position to determine tibial varum although aligning the heel to the angle of the tibia (thus removing any influence of compensation on the position of the tibia) may be of value. I have long felt that the relative mobility of the rear foot on the tibia (i.e. the difference between the degree of tibial varum and the relaxed stance position) will be informative, particularly if combined with navicular drop and change in midfoot width. Together, these 3 can give us an idea of the degree and direction of potential motion within the foot and thus the relative loads (or moments).

    Finally, whatever approach you take to resolve symptoms, you are relieving tissue stress. It is how you come to your method of treatment that varies, i.e. the paradigm one uses. Thus tissue stress does work and there must be both kinematics and kinetics at play for that to work - irrespective of the approach you take. To say tissue stress does not work is, at best inaccurate.

    Trevor
     
  32. efuller

    efuller MVP

    In podiatry school I do remember this point being much more emphasized in biomechanics classes as opposed to surgical classes. It is important to know the difference between a soft tissue equinus and a bony equinus. It is important to be able to identify the structure that causes the end of range of motion.

    Part of the problem with Root normal is seen here. An inverted heel alignment is seen as something that needs to be treated. Patient rarely come in complaining of inverted heels. Why is an inverted heel a problem? How does an inverted heel bisection explain why the patient is having the problem that they are having. I agree that you need the Coleman block test to differentiate between two different causes of an inverted heel. However, is the inverted heel really the problem?

    Another way to to explain the Coleman block test is that the foot at rest is in equilibrium either at the end of range of motion of the STJ or somewhere relatively far inverted from the end of range of motion, in the direction of pronation, of the STJ. Incidentally, those feet that are significantly inverted from end of range of motion of pronation are usually still pronated from "neutral" position and they have lateral instability. Pushing those feet toward neutral position often makes problems worse. So, when you put a block under the lateral forefoot, you are moving the center of pressure laterally and this will increased the pronation momnet from the ground. If there is range of motion available, this pronation moment will cause the STJ to evert, letting you know that the STJ was not at its end of range of motion. If the STJ does not evert when standing on the block, you are pretty sure that the STJ is at end of range of motion. To be sure you can add more pronation moment by asking the patient to contract their peroneal muscles.

    Surgical dorsiflexion of the first ray, will tend to shift the center of pressure of ground reactive force more laterally. Understanding how ground reaction force causes pronation and supination is more clear than just thinking about compensations for plantar flexed rays. If you wanted to do surgery for lateral ankle instability, you could also consider doing a lateral calcaneal slide osteotomy as this would shift more foot lateral to the STJ axis. It's not how inverted the heel is, it is the location of the heel relative to the STJ axis. "Modern" biomechanics is trying to treat pronation and supination of the foot without understanding the moments that cause those motions.

    Eric
     
  33. Jeff Root

    Jeff Root Well-Known Member

    One should, to the best of their ability, know the source of the moments, and not just the effect of the moments that they are attempting to treat. Too many practitioners treat STJ pronation without necessarily knowing why it is occurring and what is causing it. They simply see a heel that appears too everted in resting stance or during a gait exam (many don't even do a gait exam anymore!) or they see symptoms that in their mind are "associated" with excessive pronation, and they simply use an OTC or custom orthosis. One reason for this is because they can't get paid for a proper biomechanical exam so they don't want to invest the time to examine something that they aren't getting reimbursed for.
     
  34. drhunt1

    drhunt1 Well-Known Member

    Trevor-my post was right on target, and is no more rude than how I've been treated here by the TST Pods, in general, and Kirby in particular. As they say...what goes around...right? Have you ever wondered why Dr. Phillips doesn't post here anymore? The answer to that question will answer your concerns about my "behavior" and approach.

    Putting the foot through a ROM analysis, comparing RCSP to NCSP is just part of the brief exam. But is really important...just as important, IMHO, as taking weight bearing plain film radiographs. The reality is that no Podiatrist I know bothers to perform a complete biomechanical exam on any patient. There's simply no time to do this, as we hustle from one room to the next in our attempts to keep our lights on and our doors open. Reimbursement for biomechanical exams don't pay the bills, and I don't believe are even valid anymore, (I haven't used them in years)...as practitioners have slit the throat of that goose as well, too. But I find that it's not just a good measure of the correction I need, but it's a great way to demonstrate to the patient, (or parent), how the hallux straightens in NCSP as opposed to be in an rotated position in the frontal plane while in RCSP.

    As far as your comments about tibial varum increasing lateral load is concerned, I guess that would be true if there was not sufficient ROM to compensate for that deformity. In theory, I suppose you're correct, but the reality is, few Pods I know here in the States measure it, or even consider it. Thus...assessment of the ROM of the STJ is critical and must be included in the exam. I see quite a few patients that have had bunion surgery elsewhere and they come to me hoping that I have a magic wand. I'm shocked and surprised that the other Podiatrists don't demand the patient purchase orthotics post-op. I won't even consider performing surgery unless they agree to that. Orthotics are the "great equalizer" post-op. And they can correct or compensate for "not so good" surgical outcomes.

    You can write and scream kinematics all you want...but as far as the US population of Pods are concerned, most aren't practicing that...even if they state they are.
     
  35. efuller

    efuller MVP

    I agree that terminology must be exact and consistent. The terminology should also be useful. Which of the multiple methods for determining neutral position be used for determining forefoot to rearfoot relationship and why. Do those different methods give the same result? Do the multiple methods make the determination of neutral position inconsistent. What rationale was used for determining what position of the STJ should be called neutral? Was it a good rationale? Bill Orien called neutral position a figment of Mert Root's imagination (Biomechanics Summer School 2001).

    Jeff, I agree with your premise, that at the extremes a forefoot varus foot will function differently than a forefoot valgus foot. I don't think the best non weight bearing position to assess this the neutral position that was taught. I like taking the foot, of a seated person, and maximally pronating the STJ and loading the first and fifth rays and seeing if the plantar plane across the metatarsal heads is inverted relative to a line perpendicular to the leg. (Well you could take into acount tibial varum, but this is such an inexact, eyeball measurement that if I see that the foot is close to being in varus I will pay much more attention to the weight bearing exam. John Weed described a weightbearing exam where he tried to get his fingers under either side of the forefoot.)

    Some points from this.

    The concept should be whole foot varus and not rearfoot or forefoot varus. The STJ can't tell the difference between forefoot varus and rearfoot varus. When the STJ is at end of range of motion, you get different problems than when it is not at end of range of motion.

    The non weight bearing exam should load both first and fifth met heads because this is the reality of weight bearing.

    This method could be used to define foot varus or valgus without using neutral position.

    What do you think Mert would have said to these alterations of his system?

    Eric
     
  36. Jeff Root

    Jeff Root Well-Known Member

    In order to measure the ff to rf relationship the foot must be positioned when non-weightbearing and the clinician must be in a position to measure the ff to rf relationship. This is done with the patient prone and while viewing the posterior surface of the heel. I'm only aware of four indicators that can be used to position the STJ in the neutral position in the open chain. The clinician can look for congruency between the curves above and below the lateral malleolus, can move the STJ back and forth from a supinated to a pronated position and use observation and can also feel for the low point in the arch of motion of the STJ that occurs when the foot reaches the neutral position, and can use palpation to check for talar congruency. Any one, or as much as all four of these indicators can be used to identify the STJ neutral position. Each indicator decrease when you move away from the neutral position and increases as you approach the neutral position. As a result, it really isn't that difficult for a properly trained clinician to locate the neutral position or to position.

    The second part of your question, which you actually didn't even ask, is how do you measure the ff to rf relationship. The ff to rf relationship can only be measured relative to a heel bisection. I use Root's exact technique (palpation of the posterior surface of the calcaneus) and Root's forefoot measuring device. I don't know of any other instrument that can measure ff to rf as accurately as Root's device (which for the record, he invented but did not profit from as he let 100% of the profit go to the company that manufactured it because he just wanted an accurate tool and had no intention of profiting from it). As far as the accuracy of heel bisection, as Root wrote, inconsistent or poor technique leads to inconsistent results. Unfortunately many clinicians don't strictly follow Root's heel bisection technique nor use the tool he developed and as a result, they get poor and inconsistent results.

    [/QUOTE]Jeff, I agree with your premise, that at the extremes a forefoot varus foot will function differently than a forefoot valgus foot. I don't think the best non weight bearing position to assess this the neutral position that was taught. I like taking the foot, of a seated person, and maximally pronating the STJ and loading the first and fifth rays and seeing if the plantar plane across the metatarsal heads is inverted relative to a line perpendicular to the leg. (Well you could take into acount tibial varum, but this is such an inexact, eyeball measurement that if I see that the foot is close to being in varus I will pay much more attention to the weight bearing exam. John Weed described a weightbearing exam where he tried to get his fingers under either side of the forefoot.)

    Some points from this.

    The concept should be whole foot varus and not rearfoot or forefoot varus. The STJ can't tell the difference between forefoot varus and rearfoot varus. When the STJ is at end of range of motion, you get different problems than when it is not at end of range of motion.

    The non weight bearing exam should load both first and fifth met heads because this is the reality of weight bearing.

    This method could be used to define foot varus or valgus without using neutral position.

    What do you think Mert would have said to these alterations of his system?

    Eric[/QUOTE]

    Eric, I think Mert would have said that you can only determine the presence of forefoot varus or valgus relative to a calcaneal bisection and that the standard position to determine the presence and degree of ff varus or valgus is with the STJ in the neutral position while the MTJ is simultaneously in fully pronated position. I think Mert would have said although you can measure the ff to rf relationship while the STJ is fully pronated and while the 1st and 5th mets are loaded, the angular relationship measured would not be a ff varus or a ff valgus according to his definition or classification of these conditions and that calling this a ff varus or valgus would create confusion. I think he would have said that what your are determining is whether the forefoot is inverted or everted to some reference (the heel, the floor, or the leg) while the STJ is fully pronated. This goes right back to the heart of the quote from him that I wrote yesterday: "Advancement of clinical treatment and knowledge of the foot have been seriously impaired by a lack of specifically defined and commonly accepted terminology".
     
  37. efuller

    efuller MVP

    Jeff, I agree with your premise, that at the extremes a forefoot varus foot will function differently than a forefoot valgus foot. I don't think the best non weight bearing position to assess this the neutral position that was taught. I like taking the foot, of a seated person, and maximally pronating the STJ and loading the first and fifth rays and seeing if the plantar plane across the metatarsal heads is inverted relative to a line perpendicular to the leg. (Well you could take into acount tibial varum, but this is such an inexact, eyeball measurement that if I see that the foot is close to being in varus I will pay much more attention to the weight bearing exam. John Weed described a weightbearing exam where he tried to get his fingers under either side of the forefoot.)

    Some points from this.

    The concept should be whole foot varus and not rearfoot or forefoot varus. The STJ can't tell the difference between forefoot varus and rearfoot varus. When the STJ is at end of range of motion, you get different problems than when it is not at end of range of motion.

    The non weight bearing exam should load both first and fifth met heads because this is the reality of weight bearing.

    This method could be used to define foot varus or valgus without using neutral position.

    What do you think Mert would have said to these alterations of his system?

    Eric[/QUOTE]

    Eric, I think Mert would have said that you can only determine the presence of forefoot varus or valgus relative to a calcaneal bisection and that the standard position to determine the presence and degree of ff varus or valgus is with the STJ in the neutral position while the MTJ is simultaneously in fully pronated position. I think Mert would have said although you can measure the ff to rf relationship while the STJ is fully pronated and while the 1st and 5th mets are loaded, the angular relationship measured would not be a ff varus or a ff valgus according to his definition or classification of these conditions and that calling this a ff varus or valgus would create confusion. I think he would have said that what your are determining is whether the forefoot is inverted or everted to some reference (the heel, the floor, or the leg) while the STJ is fully pronated. This goes right back to the heart of the quote from him that I wrote yesterday: "Advancement of clinical treatment and knowledge of the foot have been seriously impaired by a lack of specifically defined and commonly accepted terminology".[/QUOTE]

    Jeff, you are just repeating what is in the good book. I'm asking is there really a neutral position.

    You glossed over my question of do those different methods of determining neutral position result in the same position of the joint. I don't think that they will all of the time. But more importantly, are those methods really the best way to find a joint position in which we can compare the shape of one foot to another. Why do all those different methods end up in an ideal position of the foot for..... ? I'm asking people to think if Mert choose the right neutral position. As Bill Orien said neutral position is a figment of Mert Root's imagination.

    I'm also asking to consider other methods for determining forefoot position. There is a valid concept somewhere in there. Is the method that has been passed down to us really the best method. As Jeff has said Mert was surprised that things were unchanged after a period of time. There are some problems with the determination of forefoot to rearfoot as described in Vol 1. I call it the supinatus problem. If persistant high loads on the medial forefoot can create a more dorsiflexed position of the medial forefoot the forefoot to rearfoot measurement will be changed over time. Is the measurement that we see the true measurement? Should we be looking at the measurement with the supinatus or the measurement that we think the measurement was before a long time of medial forefoot weight bearing. Why is one better than the other?

    Eric
     
  38. Jeff Root

    Jeff Root Well-Known Member

    I have answered your question about whether there really is a neutral position of the STJ many times before or the Podiatry Arena and old Podiatry Mailbase. There is a clinical STJ neutral position and a theoretical neutral position. I described how to locate the neutral position clinically.

    As for your next question, there are many positions in which we can compare the shape of one foot to another. The issue is not whether there is a best position or not. The issue is what are you looking to compare, what is the best position to evaluate what you are looking to compare, and why? Root selected the neutral position of the STJ and the pronated position of the MTJ as his standard position in which to compare feet and he tied it in with his treatment protocol in which the foot is usually, but not always casted in this same position. He was successful in demonstrating the benefit to his examination technique and prescription protocol which is why so many clinicians have utilized the same approach. If you feel you have a better theory and clinical approach, then the burden is on you if you want to convince others to use it just as the burden was on Root to demonstrate the benefit of his approach. He made a lot of personal sacrifices to accomplish that. Since I'm not aware of anyone else who uses your approach and since I haven't used it myself, I can only question the logic of your approach.

    I will let Bill Orien explain what he may have meant by his comment but I can tell you that Mert Root was very confident in the theoretical definition and clinical benefit of the neutral position. He was also very clear in stating that in most feet, the foot could be a few degrees inverted or everted from the neutral position without causing major changes in the shape of the foot and without compromising the clinical benefit of the neutral position. In other words, there is an acceptable range or margin of error with his approach.

    As for changes in the forefoot to rearfoot relationship that can occur over time, our ff to rf measurement is a snapshot in time. Yes, it can and often does change due to alterations in the forces acting on the foot over time. An inverted forefoot condition, be it forefoot varus or forefoot supinatus, can increase or decrease over time. An everted forefoot condition, be it forefoot valgus, forefoot pronatus (I believe there is such a thing, and technically an acquired plantarflexed 1st ray is a form of ff pronatus), or an everted forefoot resulting from a plantarflexed 1st ray, can increase or decrease over time. I have sometimes seen forefoot to rearfoot relationships change very rapidly in response to the alteration of forces created by foot orthoses. Typically functional foot orthoses will, in some feet, decrease inverted and everted ff to rf relationships. As a rule I don't think I have seen inverted or everted ff to rf relationships increase in response to functional foot orthotic therapy.
     
  39. The bottom line to this discussion is that the podiatrist and foot-health clinician that knows their anatomy, the biomechanics of the foot and lower extremity, the biomechanics of foot orthoses and the concepts of Tissue Stress Theory does not need to measure subtalar joint neutral, forefoot to rearfoot relationship, subtalar joint range of motion or neutral calcaneal stance position to prescribe excellent custom foot orthoses for their patients. In other words, nearly all of those measurements, which the people that dogmatically preached Subtalar Joint Neutral Theory to us for decades as the only way to make "correct" custom foot orthoses, don't really need to be done in order to make great custom foot orthoses.

    In addition, the teaching of "Subtalar Joint Neutral Theory" over the years at the California College of Podiatric Medicine and other schools of podiatric medicine as the "only way to do things" or "the gospel", rather than an alternate theory of many theories, in my opinion, has done as much harm to podiatry as it has done good to podiatry. I have been trying to "unteach" Subtalar Joint Neutral dogma for the past 30 years.

    The Subtalar Joint Neutral dogma, full of errors and inconsistencies, which has been passed on from generation to generation of podiatrists, blinds many podiatrists to the truth of how the foot and lower extremity actually works. Better theory needs to be actively taught so that podiatrists and other foot-health clinicians can start to move on past their shallow and blind-alley understanding of foot and lower extremity biomechanics, limited by the unrealistic dogma of Subtalar Joint Neutral Theory, so that they can open their minds up to the bright light and wide-open landscape of educational opportunities offered by the brilliant minds within the many modern minds of the International Biomechanics Community.

    Those that continually want to refer to the past contributions of our ancestors of podiatric biomechanics, keep things as they were 35 years ago, and not keep an open mind to change and move on to better theory, are only helping their own memories of these ancestors. These people are not helping podiatrists, other foot-health clinicians, future podiatrists and foot-health clinicians, or their patients. As far as I can see, the Tissue Stress Theory is the theory which best optimizes the clinical practice of foot orthosis therapy, not Subtalar Joint Neutral Theory. That is simply a fact that is becoming more and more apparent as we move further along into the 21st century.

    For those that disagree with me, and still believe all the premises of Subtalar Joint Neutral Theory, please answer me the following question: How many lectures are being given nationally and internationally on Subtalar Joint Neutral Theory at podiatric or pedorthic seminars versus lectures on Tissue Stress Theory? I can tell you very clearly, there really is no competition anymore. The future for podiatry and other foot-health clinicians for teaching the complexities of foot orthosis prescription is Tissue Stress Theory, not Subtalar Joint Neutral Theory.
     
  40. Jeff Root

    Jeff Root Well-Known Member

    I think the bottom line and indisputable point in this discussion is that foot-health clinicians still use and rely on terminology, techniques and practices that came out of Root theory, the neutral classification system and Root's custom foot orthotic prescription and fabrication protocol and as a result, makes the Nester et. al. suggestion to abandon these terms, techniques and practices unrealistic. Kevin, I never said that clinicians should practice exactly like they did 30 or 40 years ago. Things have changed for a variety of reasons, including how clinicians get reimbursed, making it impractical to do a more comprehensive biomechanical exam. We also have new knowledge and techniques that have changed how clinicians practice. But even you have admitted that you still use open chain ROM examination of the ankle, STJ, 1st ray, etc. which is in direct conflict with Nester's recommendation. The tissue stress approach incorporates terms, techniques and practices that originated from Root's work. This clearly creates frustration or conflict for some who want to dismiss all of Root's work but in all practical purposes, can't.
     
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