Welcome to the Podiatry Arena forums

You are currently viewing our podiatry forum as a guest which gives you limited access to view all podiatry discussions and access our other features. By joining our free global community of Podiatrists and other interested foot health care professionals you will have access to post podiatry topics (answer and ask questions), communicate privately with other members, upload content, view attachments, receive a weekly email update of new discussions, access other special features. Registered users do not get displayed the advertisements in posted messages. Registration is fast, simple and absolutely free so please, join our global Podiatry community today!

  1. Everything that you are ever going to want to know about running shoes: Running Shoes Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
  2. Have you considered the Critical Thinking and Skeptical Boot Camp, for taking it to the next level? See here for more.
    Dismiss Notice
  3. Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
Dismiss Notice
Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
Dismiss Notice
Have you liked us on Facebook to get our updates? Please do. Click here for our Facebook page.
Dismiss Notice
Do you get the weekly newsletter that Podiatry Arena sends out to update everybody? If not, click here to organise this.

Supination Resistance Test

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Ray Anthony, Aug 22, 2014.

  1. Ray Anthony

    Ray Anthony Active Member


    Members do not see these Ads. Sign Up.
    Is anyone attempting to quantify supination resistance and if so, how?

    Thanks

    Ray Anthony
    Cayman Islands
     
  2. Craig Payne

    Craig Payne Moderator

    Articles:
    6
  3. I believe that Simon Spooner and Ian Griffiths were working on a device to measure supination resistance some time ago also. More research really needs to be published on this test first described in the medical literature 22 years ago (Kirby KA, Green DR: Evaluation and Nonoperative Management of Pes Valgus, pp. 295-327, in DeValentine, S.(ed), Foot and Ankle Disorders in Children. Churchill-Livingstone, New York, 1992). I've actually been doing the test now for about 30 years starting in my Biomechanics Fellowship at CCPM.
     
  4. Griff

    Griff Moderator

    Hi Ray

    Following Kevin's description of the manual test in 1992, Craig and the team at La Trobe were first to build a jig which measured the force required to supinate the foot and this was detailed in their three publications published in JAPMA in 2003:

    Payne, C. B., Munteanu, S., & Miller, K. (2003). Position of the subtalar joint axis and resistance of the rearfoot to supination. Journal of the American Podiatric Medical Association, 93 (2), 131-135.

    Noakes, H., & Payne, C. B. (2003). The reliability of the manual supination resistance test. Journal of the American Podiatric Medical Association, 93 (3), 185-189.

    Payne, C. B., Oates, M., & Noakes, H. (2003). Static stance response to different types of foot orthoses. Journal of the American Podiatric Medical Association, 93 (6), 492-498.

    I built a jig in 2010 and spoke to Craig before doing this. One of his beliefs was that a limitation of his device was that it may not mimic the manual test closely enough given that the strap traversed the entire foot. I designed mine to try and address this and instead apply a purely plantar-dorsal force with some aluminium 'fingers' (identical length and width of the two fingers I use for the manual test). This was also published in JAPMA:

    Griffiths, I. B., McEwan, I. M. (2012). Reliability of a new supination resistance measurement device and validation of the manual supination resistance test. Journal of the American Podiatric Medical Association, 102 (4), 278-289.

    Simon took this one step further and built a jig in which there are forefoot and rearfoot plates that can be independently changed in the frontal plane - this is exciting as we may be able to identify how/if supination resistance changes with different wedging/posting (and may essentially be a step toward quantifying the kinetic response to foot orthoses). No publication yet but some very cool pilot data that he presented at the Biomechanics Summer School in 2012.

    As with all things still much we don't know. "Work to do" as they say...

    I have some vague recollection that Mart was also collecting some data a while ago? To my knowledge however the above 4 papers are the only published on the subject since Kevin's original detailing of the manual supination resistance test 22 years ago (when I was a 14 year old boy running round chasing a football).
     
    Last edited: Aug 24, 2014
  5. You are getting to be an old man, Griff....36 years old and all. It's about time you started lecturing on a bigger stage...it's now your time.:drinks
     
  6. Griff

    Griff Moderator

    I have two 'gigs' in the next 3 months. Buy shares in tumbleweed and rotten tomatoes now...
     
  7. Please share...where and what are you lecturing on, Ian?
     
  8. Griff

    Griff Moderator

    I just emailed you about it Kevin - didn't want to detract from the thread.
     
  9. Ian Linane

    Ian Linane Well-Known Member

    'bout time Griff. Be interested in knowing where and when.
     
  10. Trevor Prior

    Trevor Prior Active Member

    so, if one requires xx force to supinate a weight bearing foot, how much force is required to supinate that foot when moving at speed, variable speed and at different parts of stance as the whole foot is only weight bearing for a fraction of that time?
     
  11. More than in static bipedal stance, since F = ma. The key is that static supination resistance does appear to be predictive of pathology unlike the vast majority of static tests, navicular drop withstanding- if memory serves Craig demonstrated this in some unpublished data where he looked at PT tendonitis versus peroneal tendonitis.
     
  12. Trevor Prior

    Trevor Prior Active Member

    That would depend on the direction of the force. In static stance, it is nearer to perpendicular to the supporting surface. Dynamically, the angle will vary. Hitting a stone or small slope / angle at speed can cause a greater reaction than simply standing on it - thus, it may be possible to direct motion with less rather than more control.

    Furthermore, the degree of motion observed decreases with increasing velocity (i.e. the joints move less) and thus less rather than more may be required.
     
  13. Agreed, the vertical component will vary, but since the vertical components are greater during the first half of stance during walking/ running than during static stance... you can fag packet it with mg cos theta and then ma cos theta, and as the STJ generally pronates during the initial contact phase, then the STJ axis will move medially reducing the lever arm and thus increase supination resistance further, as Craig demonstrated in one of his publications. Since, by defintion, supination resistance is a measure of the vertical component, this would seem to be the component of interest here, as such supination resistance should be higher (at least during the first half of contact) during dynamic function, than during static stance. Couple that with the single limb stance phase versus the double limb support of the static measure and I'd say its a fair assumption that dynamic supination resistance is always likely to be higher than the static measure- unless there is a point in the contact period of gait when the vertical component of ground reaction force is less than body weight- is there?
     
  14. Trevor Prior

    Trevor Prior Active Member

    well... accepting that this is all theoretical, if one considers the force time curve, the load slowly rises and will hit a point at which it is equivalent to body weight and then exceed it. As forward progression continues, the CoM rises so the force reduces before rising again (walking that is) although, off the top of my head, I cannot tell you if that is still more or less than body weight in midstance. As this occurs nearer midstance, the direction of force will be changing.

    If one then considers that the pattern of pronation varies with some later etc., the deforming force may be occurring at a later stage. In addition, we do not know whether or not by trying to reduce pronation in the early stage we reduce the amount of force necessary to resist pronation.
    I suspect that, as with most things gait related, in some we will need less control to affect function dynamically, in some it will be equal and in others it will be more.

    You also raise some other interesting points:
    1. Regarding the STJ axis - As this moves and changes position with the joint through gait so, theoretically will the relative influence on the ground reaction force and muscle tendon action.

    2. Regarding single versus double limb support – in order to be stable over a single foot, the CoM shifts so that it is ‘over’ the foot compared to double support or standing whereby it is more central thus more of a medial force vector.

    So, not only do we have the effect of ground reaction forces and the direction of the force vectors with forward progression, we also have a varying STJ axis position, varying degrees of body weight acting on the foot, the resultant force vector fluctuating between single and double limb support, the amount and timing of pronation varying and by how much we have to limit pronation unknown.

    So how much support is needed to change position or function?

    If I were to throw a punch but at a very slow controlled speed, quite a bit of effort would be required to re-direct my hand. If however, I throw a punch but at a very quick speed, it is easier to deflect with less force. Could this happen during gait?
    As always, there is less we do not know than know.
     
  15. Further thoughts: what's probably of greater significance than the angulation of the GRf vector you refer to above is the internal supination moment created predominantly by the PT and AT muscles, but also any of the supinators during dynamic function, this will reduce the net supination resistance during dynamic function while these muscles are active. Hope that helps.

    If it was less than body weight at midstance they'd be flying, Newton's third and all that:) At midstance the GRF vector is nearest it's vertical, BTW.

    if you wanted to change position (with regard to the joints involved) with an orthosis then the force exerted by the orthosis should need to be greater than the supination resistance at any given time without the orthosis in situ. However, this does not account for CNS mediated effects. Personally, I'm not too fussed about changing position though; if you wanted to change function, any change in force will do, that's what makes this so interesting.
     
  16. Trevor Prior

    Trevor Prior Active Member

    All interesting and valid points. Regarding body weight, the point I was trying to make is that there is fluctuating load beneath the foot with varying points of contact and, at stages, the net load is less than body weight.

    We have not even started talking about the effect of factors proximal to the foot and ankle!!

    Back to work this week - here we go again.
     
  17. Griff

    Griff Moderator

    Just to add on to the good points already made:

    We haven't quite mastered reliably and validly quantifying static supination resistance yet and this is probably a sensible thing to do. Certainly we need better (more convenient and repeatable) ways of doing so, if we can.

    From all the data I collected it was clear that supination resistance showed high between subject variation (what nowadays doesn't right?!) Those with history of chronic lateral ankle instability generally have low supination resistance (approx 100N) whereas it is not uncommon for feet with PTTD to register values of 300N+. Bonus points for those acknowledging the correlation/causation considerations there. From memory Craig has loads of similar unpublished data. I seem to recall he compared supination resistance in symptomatic and asymptomatic limbs of individuals with unilateral pathology and there was a relationship? Craig?

    In any case there is still much we do not know. We still have no normative data. We still need powerful enough studies that we can build a trustworthy regression model. We still need to understand the variables that influence supination resistance (we've looked at body weight, foot posture and STJ axis spatial location thus far). We still need to understand how the clinical test may direct our treatments (i.e. if/how we can manipulate supination resistance with orthoses prescription). At some point along the way the consideration of dynamic concepts discussed above become very important.

    All good fun.
     
  18. And this might be useful because?

    "But even if thousands of cases had been used it would be fallacious to reason that all feet in which the scaphoid tubercle is higher than the average, are normal, and all feet in which the tubercle is lower, are abnormal, because the average is obtained just as much from the figures below as from the figures above. Moreover, the chief point shown in the hundred cases is that there is marked variation in the height of the scaphoid in apparently healthy feet. Consequently, as the average is based on that variation, it has no significance further than what the term indicates, representing simply an average of normal variation. Such an average, therefore, cannot serve as a basis from which to estimate deformity." Feiss

    I don't like comparing to "normative databases" because they are meaningless to the individual in front of you.
    It always has done, as Feiss stated in 1909 - worth a read again.

    In terms of dynamic supination resistance, I think there is more mileage in observing the dynamics of navicular displacement in concert with force plate data.
     
  19. Griff

    Griff Moderator

    Do you feel there is no place for getting a feel for a 'normative' range from a very large asymptomatic cohort? If it was suggested that a 'normative' range was 100N-350N, for example, would that not be of some use (if only as a reference point)? Would this database be meaningless if a dude then rocks in exhibiting a 500N supination resistance? Genuine questions.

    Point taken regarding suggesting an "average" supination resistance from a large cohort and then (falsely) intimating this is ideal (e.g. 210N or similar arbitrary figure). Need to be careful not to fall into same trap that various measures of foot posture did, and instead embrace variation.
     
  20. Normative databases are widely used within clinical medicine, however there are a number of issues which apply to all and there are some specific issues which we can discuss with regard to a normative database for supination resistance.

    We do not have a standard apparatus for measuring supination resistance. A normative database obtained using your apparatus could not be applied to the results obtained from Craig' jig or mine. We then have the problem of inter-observer error, which if memory serves your study found to be quite high; if the normative database is constructed from measurements I have taken, can you reliably compare the results for a subject that you have assessed to my database?

    Then there are problems with covariance and the "predictors" of supination resistance. We can guess that body weight is going to influence supination resistance and Craig showed that STJ axial position influences the variation in supination resistance too, so we should need to normalise data or at least account for these variables too when drawing comparison to the database (what is the inter-observer error like for assessing STJ axial position?- again we are comparing your measures to the measures of whoever constructed the database). We have accounted for some of the variance in supination resistance, however, we have not accounted for all of the variance in supination resistance- what other factors should we need to normalise/ include in our model?

    We then have problems with the demographics of the database itself- racial, sexual, age etc. Do we need separate databases for males and females? Asian's versus Europeans? Children versus adults?

    Finally, we can partition the variance in supination resistance to something like: Supination Resistance = Genotype + Environment + (Genotype x Environment) + measurement error, so who cares if I'm an outlier compared to your database? Since your database is a snapshot in time of a given population, the fact that I'm different to your population doesn't tell you much, other than I'm different to you population- given that none of the individuals in your database share my genotype nor my environmental influences, why would you expect me to conform to your norm?

    Your normative database may have been plucked from individuals who were "clinically normal" at the time of measurement- does this mean they did not go on to develop pathology after measurements were taken from them?

    All I have time for, but enough to get you thinking I hope.
     
  21. efuller

    efuller MVP

    My 2 cents on supination resistance test.

    How do you account for differences in muscle activiation. There are patients whose posterior tibial muscle, and other patients whose peroneal muscles, are active in "relaxed" stance. These patients may be rare, but they exist.

    I can see Simon's points about Normative data. What do you use it for. However, if you measured a large number of people, and then followed them for the developement of pathology. You can make a good case that the outliers will be more likely to develop pathology. You might find a good predictor for who should get a medial or lateral heel skive device before pathology develops.

    Eric
     
  22. Except when you inevitably get some outliers that don't develop pathology and some near the mean that do.
     
  23. It has been interesting for me to read this discussion on the Supination Resistance Test which is a test I developed during my CCPM Biomechanics Fellowship back in 1984-1985. Maybe a little bit of background on why I started experimenting with and using the Supination Resistance Test will be helpful for all those following along.

    I started experimenting with the Supination Resistance Test soon after I started to measure the subtalar joint (STJ) axis location on most of my patients and most of my students at the time by pressing on the bottom of their feet (Kirby KA: Methods for determination of positional variations in the subtalar joint axis. JAPMA, 77: 228-234, 1987).

    I became excited when I started to see a correlation of STJ axis location to foot pathology in many of my patients. In addition, in 1985, I was starting to better understand how the balance of STJ pronation and supination moments (concept of rotational equilibrium) would be able to cause the pathologies that I was seeing in my patients. It also made me very happy during this time of exploration of ideas when I could find patients with asymmetrical STJ axis location which correlated to their asymmetrical foot/lower extremity pathologies.

    What I was missing in those early years of exploration of ideas was a way for me to quantify how much pronation moment was actually present within the foot during static stance since I strongly felt that the medial STJ axis position was causing excessive STJ pronation moments and also STJ pronation-related pathologies.

    During my Biomechanics Fellowship, I realized that the posterior tibial (PT) muscle was the strongest supinator of the STJ, that the PT tendon attached mainly to the navicular and that the PT tendon was often injured in feet with a medial STJ axis (i.e. PT tendinitis). Therefore, upon giving the problem of trying to quantify subtalar joint pronation moments some thought, I decided the following: "Why not try assessing subtalar joint pronation moments acting on the foot by assessing the force required by the posterior tibial muscle to supinate the subtalar joint by using manual force from my own hands on the medial navicular, where the posterior tibial muscle inserts?"

    I soon started experimenting with the Supination Resistance Test in early 1985 during my Biomechanics Fellowship and was quite impressed by the initial results in that it confirmed my hypothesis that a medially deviated STJ axis was much harder to supinate due to the decreased STJ supination moment arm from the medial navicular to the STJ axis. I became very impressed also with how much force was required from my hand with the Supination Resistance Test to supinate a small child's foot with severely medially deviated STJ axes and how little force from my hand was required with the Supination Resistance Test to supinate a large man's foot that had a laterally deviated STJ axis.

    I had been using the Supination Resistance Test, therefore, for approximately five years before I first wrote about it in late 1990 in the chapter I coathored with Donald Green, DPM, which was eventually published in 1992 (Kirby KA, Green DR: Evaluation and Nonoperative Management of Pes Valgus, pp. 295-327, in DeValentine, S.(ed), Foot and Ankle Disorders in Children. Churchill-Livingstone, New York, 1992). In addition, I have further written about the Supination Resistance Test in my Precision Intricast Newsletter Books. http://www.dpmlab.com/html/newsletter03.html

    While I think a better Supination Resistance Testing Machine would be helpful (i.e. one which actually only pushes up on the medial navicular with a compression force and not pulls up on the whole plantar arch from lateral to medial), I think the real benefit of the Supination Resistance Test is it allows easy assessment of asymmetries between the left and right feet of patients that then allows the clinician to assess the prevailing STJ moments and the STJ axis location between the two feet of patients. In addition, the Supination Resistance Test allows the clinician to broadly assess differences in magnitudes of pronation moments from one patient to another as a way to confirm assessments of STJ axis spatial locations from one patient to another.

    I believe that to use the Supination Resistance Test in isolation without other clinical assessments makes no sense at all. However, I know of no other clinical test other than the Supination Resistance Test that easily allows the clinician to actually "feel" how much muscle force a patient must use during standing to supinate their foot. This ability of the clinician to "feel the force", so to speak, should then allow them to begin to better appreciate the mechanical significance of STJ axis spatial location relative to the STJ moments that act on their patient's feet during weightbearing activities.

    If nothing else, the Supination Resistance Test, I believe, allows the clinician to better have a way to get out of the "calcaneal bisection", "subtalar joint neutral", "calcaneus inverted/everted" mindset that has been and still is being dogmatically taught in our podiatric medical schools and, as a result, should better allow the clinician to appreciate the biomechanics of forces and moments that create pathologies and also allows the human body to function during weightbearing activities.

    In other words, the hopeful result of that change in mindset from structure and position to forces and moments is that the clinician should then be better able to understand how mechanically-based pathologies are created within the human foot and lower extremity. In turn, this should ultimately allow the clinician to better design more therapeutic foot orthoses, and other treatments, for their patients.

    If the Supination Resistance Test helps to move more clinicians into understanding the interplay between internal and external forces and moments and how they interact which each other to create pathologies, and away from the idea that structure, position and joint range of motions can predict function and pathology, then I feel my work in creating, writing about, lecturing on and promoting the Supination Resistance Test over the years will have served its useful purpose.

    That's my two cents.:drinks
     
  24. Griff

    Griff Moderator

    Agree. As I said a couple of posts back: "We haven't quite mastered reliably and validly quantifying static supination resistance yet and this is probably a sensible thing to do. Certainly we need better (more convenient and repeatable) ways of doing so, if we can". Certainly think this is something that needs to be signifcantly improved upon for any future research regarding supination resistance to have any meaning.

    Agree. From my same post: "We still need to understand the variables that influence supination resistance (we've looked at body weight, foot posture and STJ axis spatial location thus far)". There are clearly contributing factors that we aren't measuring/haven't measured, or even identified, yet.

    Fair point. Answer: I don't know, but probably I guess...

    Can't argue with that. I'm trying not to think about this as a 'norm' and looking for people to conform, but rather a range or spectrum of values, and subsequent identification of where an individual roughly sits on that spectrum. Perhaps 'normative data' is not the most appropriate terminology here?

    True - and that data would hopefully gestate into a prospective study... But, clearly we are not close to being there yet. All comes back to having a measuring device with good intra and inter-rater reliability and better prediction models.

    Plenty. I do take & appreciate your points regarding normative databases.
     
  25. Trevor Prior

    Trevor Prior Active Member

    I agree with the points Simon makes regarding issues with normal databases and all need to be considered. However, I also agree with Eric that looking at outliers can guide us as to whether the ‘measure’ in question is within a more normal range or rather less abnormal range or not. That someone may have an issue and be within the normal range does not mean that the range is incorrect, it may simply mean that the function that particular measures assess, is not relevant to the presenting condition. In other words it occurred for another reason.

    Similarly, if someone was an outlier, and asymptomatic, it may simply mean that other factors are more relevant for that specific presenting complaint than the measure in question.
    That goes on to Kevin’s very valid point that one measure in isolation is of little benefit.

    Kevin, I found your post interesting although it, of course raises more questions. Whilst a deviated axis is associated with the degree of supination resistance, presumably, there are other factors which influence the degree of resistance? Calf inflexibility would be one that springs to mind, the degree of foot mobility, the degree of tibial varum etc. This may have been discussed here before so apologies if that is the case.
     
  26. Trevor:

    The Supination Resistance Test may or may not be influenced by such things as decreased ankle joint dorsiflexion or tibial varum deformity. That is not the point.

    The point is that the Supination Resistance Test is designed to attempt to determine the summation of subtalar joint pronation and supination moments [whether they come from external sources, such as ground reaction force, or internal sources, such as Achilles tendon tension] acting on the foot during relaxed bipedal stance. The Supination Resistance Test may be affected by multiple variables but, in the end, this test allows the clinician to have a method by which to determine whether the foot they are evaluating and treating will be relatively easy to supinate with an orthosis or will be relatively difficult to supinate, regardless of whether or not their patient has "calf inflexibility", "foot mobility" and/or tibial varum.
     
  27. Trevor Prior

    Trevor Prior Active Member

    I was trying to close the circle so to speak. I understand the premise of the test and that there are multifactorial things that may influence the resistance as you have clarified.

    However, identifying the factors contributing to the reason for the resistance may help guide management - i.e. calf stretches / heel raises for a tight calf, tib post strengthening for a weak muscle, orthoses to alter inversion / eversion etc.

    Any happier Ray?
     
  28. efuller

    efuller MVP

    I agree. If we established a supination resistance value at which we add a medial heel skive, we would be looking at percentages and not individuals. It would be too much to ask to have the test be perfectly predictive. If it turns out that it is not that predictive, then it would not be a good test and we look for another. An interesting question is whether we should be looking at supination resistance or STJ axis position. They certainly correlate, but which one will be more predictive of pathology. Is supination resistance telling us what the STJ axis position tells us, but the supination resistance has more confounding variablse such as body weight?

    What think you?


    Eric
     
  29. And that's not right, right?

    Better to build a series of multi-variate models in which each clinical test becomes a predictor with a known weighting for each pathology of interest.

    Don't you think that body weight influences STJ axial position then? I do. Nice research project for someone.
     
  30. Trevor Prior

    Trevor Prior Active Member

    I think the problem with having one test and one variable being predictive is that, as you and the previous posts allude to, dysfunction is multifactorial. The intriguing thing to evaluate would be the ‘relative’ contribution of a range of variables to supination resistance albeit, this would be difficult to assess without a repeatable method of assessment.

    Could it also be that the orientation of the axis is, in part, due to the way in which the foot is structured – in other words, dos the axis determine function and thus structure or vice versa. I know when I look at certain feet that they will have a deviated axis. However, has the degree of deviation occurred because of changes in ligamentous integrity, thus altered joint alignment, thus altered axis position?

    My question, which stems from this debate is what factors we assess clinically do we feel have a significant influence on dynamic function? I know that may sound daft – if we assess them, we must feel they are relevant. However, what you assess versus Kevin, Simon and everyone else are likely to have variations. The logical thing would be to collate them and then look at those that can be assessed repeatably and then start to evaluate how they interact. A separate thread?

    If only there were more hours in a day.
     
  31. Nope, I think the things to investigate are the predictors of pathology via multivariate models, not the predictors of the tests themselves. As Kevin noted it doesn't really matter what contributes to supination resistance, since supination resistance is just a clinical test which is influenced by multiple factors, better to direct the time and efforts of young researchers toward identifying the clinical tests that predict specific pathologies. If only all pathologies were as simple to crack as medial tibial stress syndrome in which ony two variables are required in a logistic regression model (apparently): sex [sic] and navicular drop. http://www.jospt.org/doi/abs/10.2519/jospt.2001.31.9.504#.VAinICjIafQ

    Hands up all those who provide athletic screening that employ this model? Why not, it's got a 75% success rate...?
     
  32. efuller

    efuller MVP

    If we had the studies that showed that 50% of feet with a harder than x supination resitance test developed PT tendonopathy, showed that prospectively giving those people medial heel skive devices reduced the nuber of tendonopathes to 10%, and there were no side effects, then it would seem to be ok to treat the percentages and not the individual. Assuming that individual had a supination resistance test harder than x.


    Agreed.

    I think STJ axis position will most likely to be idependent of body weight. If there was any correlation I would bet that it would occur after posterior tibial dysfunction that allowed a greater amount of abduction of the forefoot on the rearfoot. So, if there were enough people in the population with PT dysfunction and deformity, you might see a small correlation of STJ axis position and body weight. However, if you removed all people with PT dysfunction, I would bet that there was no correlation between body weight and STJ axis position.

    Eric
     
    Last edited: Sep 4, 2014
  33. If only we had those studies...
    Hmmm, I don't necessarilly agree. For example, we have studies like this one which show an increase in body mass index in concert with a more pronated foot-type as predictors of chronic heel pain, since increased body mass seems to be associated with increased foot pronation and foot pronation will tend to shift the axis medially... http://www.biomedcentral.com/1471-2474/8/41/ or maybe not: http://www.jfootankleres.com/content/1/1/6
     
  34. Trevor Prior

    Trevor Prior Active Member

    I am not as good as you guys at highlighting the area of text you are relating to but…

    Whilst a predictive test or tests for a pathology would be excellent, we also need guidance as to what types of treatment / interventions should be applied. Simon indicates that we should spend our time on the predictors and I have no problem with that other than we also need to spend time on determining what works to prevent the problem once we can predict it.

    Eric gives a theoretical example of PT tendonopathy such that, a higher resistance could predict the condition and prospectively only 10% developed it with a medial heel skive. This makes the assumption that the medial heel skive is the most appropriate treatment. If we can agree that a range of factors increase the supination resistance, surely, the most effective way to reduce this is to systematically evaluate the reduction of each component factor.

    This then gives a basis for devising treatment strategies that can be evaluated prospectively.

    I do not see how identifying contributing factors, predictive tests and management strategies are mutually exclusive.

    One also needs to consider that it does not necessarily follow that management strategies to prevent a pathology are the same as those required to manage it once it has occurred.
     
  35. None of this is mutually exclusive, and while correlation is certainly not causation, if we look to the example I gave regarding the model for prediction of medial tibial stress syndrome, a good starting point might be to either change gender or navicular drop; I know which one I'd focus my attention upon. Thus, by identifying predictors of pathology we might better direct our management.
     
  36. Trevor Prior

    Trevor Prior Active Member

    Agreed but an arch support would do that. It may be another factor that causes the drop and the same or better effect can be achieved by addressing that factor (or worse of course - do not know unless tested).

    Starting to go round in circles, sleep well.
     
Loading...

Share This Page