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Hubscher's maneuver and Fhl

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Petcu Daniel, Jun 19, 2014.

  1. Petcu Daniel

    Petcu Daniel Well-Known Member


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    Dear Members,

    2 articles ( http://www.ncbi.nlm.nih.gov/pubmed/16915976 , http://www.ncbi.nlm.nih.gov/pubmed/24703511 ) shows that a positive Hubscher test is not a good indicator of limited 1st MPJ dorsiflexion during dynamic motion and implicit of functional hallux limitus. According to Dananberg ( http://www.ncbi.nlm.nih.gov/pubmed/3814239 ) the" restriction of first metatarsophalangeal joint motion may vary in length and be less than 100 msec in duration" and "Fhl can occur at almost any point after contact in the stance phase"
    It could be possible for the metatarsophalangeal joint to be blocked for a short time after forefoot contact but at the end of the stance phase to exhibit the normal range of dorsiflexion for propulsion ?:hammer:

    Sincerely,
    Daniel
     
  2. efuller

    efuller MVP

    In my Windlass paper I tried to correlate the motions of pronation with increasing tension in the plantar fascia. So, when there is an increased pronation moment there should be increased tension in the plantar fascia. Increased tension in the plantar fascia will limit hallux dorsiflexion.

    There is more than one cause of pronation moment. The most obvious cause of pronation moment is having the center of pressure of ground reactive force lateral to the STJ axis. (Ground caused pronation). The muscles can also cause a pronation moment. When you observe the gait of patients with laterally positioned STJ axes, you will often see late stance phase pronation. (Kevin did a great video on this when he was at CCPM. Although at the time he called it a rigid forefoot valgus. He may have made the video before he developed his ideas on rotational equilibrium.) My explanation of late stance phase pronation is that with increasing tension in the Achilles tendon, prior to heel lift, there is an increase in supination moment from the Achilles tendon. If the person used no other muscles this increase in supination moment would make the STJ go to end of range of supination and there would be a sprained ankle. People have learned that they don't like sprained ankles so they choose to increase the activity of muscles that increase pronaion moment (peroneus brevis and peroneus longus) and the pronation moment from these muscles overcomes the supination moment from the Achilles tendon and you then see pronation of the STJ just before heel lift.

    So, there is both ground caused pronation and muscle caused pronation. Those feet with muscle caused pronation are much more likely to have a lateral axis and lower resistance to dorsiflexion in static stance. But in gait, there will be a high pronation moment that is likely to lead to increased tension in the fascia and hence limited hallux dorsiflexion. Conversely, those feet with medially deviated STJ axes might be using their posterior tibial muscles more to counteract the pronation moment from the ground......more hallux dorsiflexion in gait. We have to remember there is a brain connected to the foot and that brain will tend to avoid pain from high stresses on anatomical structures.

    Eric
     
  3. DrBob

    DrBob Active Member

    Hi Daniel,
    More and more papers that question the usefulness of static assessments in the understanding of functional pathologies seem to be published nowadays. Can static assessments predict dynamic performance..?
     
  4. efuller

    efuller MVP

    Yes, if you pick the right measure. One example. Static x-ray. There is a correlation between 1st metatarsal length and pressure beneath the metatarsal. (Paper by Peter Cavanagh. Sorry don't have full reference off top of my head.)
     
  5. RobinP

    RobinP Well-Known Member

    Here is my issue - is FnHL a diagnosis? If not, what is the validity of using a test to determine the presence of something that is a mechanical concept. At some point in (I would assume) the vast majority of the population, we can induce a functional hallux limitus. Does it make it pathological?
     
  6. DrBob

    DrBob Active Member

    I think the article your are thinking of, Eric, is by Morag (Structural and Functional Predictors of Regional Peak Pressures under the Foot during Walking, 1997)? What was the purpose of this paper? Well, if you believe that high peak pressures are part of the cause of ulceration then knowing the key factors (causes) for those pressures gives you a powerful method for intervention. In one respect then, Morag and Cavanagh were looking to see whether high peak pressures were caused by structural or functional factors so it's not really a case that static factors predict function, rather that combinations of factors predict elevated pressures. A peak pressure is not "function" it is simply an isolated measure of a specific parameter. If pressure were to be thought of in terms of function then it would be essential to know the pressure-time profile (or, as an absolute minimum, at least two sequential measurements). That rather brings us back to the key point: if you want to know and understand function, then measure function. Regards, DB
     
  7. Daniel:

    By definition, functional hallux limitus (FnHL) means that the hallux does not dorsiflex fully under weightbearing loads but does dorsiflex fully under non-weightbearing situations. In addition, dorsiflexion of the hallux at the first metatarsophalangeal joint (MPJ) does not occur until after heel-off so it is impossible to have FnHL in gait until after heel-off, when hallux dorsiflexion should occur.

    FnHL occurs due to strong internal plantarflexion moment at the first MPJ which prevents the external first MPJ dorsiflexion moment from ground reaction force (GRF) acting on the plantar hallux from dorsiflexing the hallux during propulsion. This strong internal plantarflexion moment is probably largely due to increased tension force within the medial band of the plantar fascia which will, in turn, cause the hallux to forcefully plantarflex into the ground causing an increase in GRF plantar to the hallux from the middle of midstance to the end of toe-off.

    Structural abnormalities such as lower medial longitudinal arch height and medially deviated subtalar joint axes wlll greatly increase the magnitude of tension force within the medial band of the plantar fascia which will also,greatly increase the magnitude of internal first MPJ plantarflexion moment and, in turn, increase the likelihood of FnHL developing during gait.

    Finally, since the muscle function present with the foot and lower extremity is verydifferent when comparing the relatively static position of relaxed bipedal standing and the dynamics of walking, it doesn't surprise me that the Hubscher maneuver (i.e. Jack's test) doesn't always correlate to FnHL during gait.

    Hope that helps.:drinks
     
  8. Petcu Daniel

    Petcu Daniel Well-Known Member

    It helps because it raise me other questions....
    This means that it is possible for the Jack's test sometimes to be correlated to FnHL during gait, isn't it ? Even if in the article the results is indicating that "cases (mean +/- SD, 36.4 degrees +/- 9.1 degrees), and controls (mean +/- SD, 36.9 degrees +/- 7.9 degrees) demonstrated comparable maximum dorsiflexion (P = .902). There was no significant relationship between static and dynamic first MTP joint motions (r = 0.186, P = .325)." ? Which means that all case and controls subjects behave in the same manner.

    Which means that we shouldn't think only in black and white and is not generally valid the conclusion of Halstead's article: "the clinical test of limited passive hallux dorsiflexion in stance is a valid test only of hallux dorsiflexion available during relaxed standing. There is no association between maximum dorsiflexion observed during a static weight-bearing examination and that occurring at the same joint during walking."?

    Sincerely,
    Daniel
     
  9. Petcu Daniel

    Petcu Daniel Well-Known Member

    Also I have the feeling that "in the vast majority of the population, we can induce a functional hallux limitus". But I put this on my (still) small clinical experience. This is why the above mentioned articles has made me much more sceptic with clinical tests raising me the question if the non-weight bearing test described in http://www.ncbi.nlm.nih.gov/pubmed/12015407
    is valid also !
    But why are you questioning if FnHL is a diagnosis ?

    Sincerely,
    Daniel
     
  10. Petcu Daniel

    Petcu Daniel Well-Known Member

    The midstance and terminal stance means 30% from gait cycle. The "restriction of the first metatarsophalangeal joint motion may vary in length and be less than 100 msec in duration (Dananberg)" which means less time that midstance and terminal stance. One question is: if this blockade happens at the begining of the midstance the hallux will remain blocked till the end of propulsion or it make sense that, sometimes, the hallux to fully dorsiflex in terminal stance / pre-swing?

    This lead in my head to a question regarding the definition of FnHL: is this strictly related only with dynamically restriction of hallux dorsiflexion ROM or there could be situations where the FnHL exist even if we have, at the end, a normal dynamically range of motion of hallux but a short restriction of this dorsiflexion has occured in the time of midstance ?


    Sorry, I don't know how to make multiple quotes in order to have less posts !
    Thanks for your patience,
    Sincerely,
    Daniel
     
  11. RobinP

    RobinP Well-Known Member

    Hi Daniel,

    I suppose I am questioning the thought process for performing the test.

    If you are doing the test to acheive a binary positive or negative result (ie does the subject have FnHL or not?) then I would suggest that you are perhaps not using what you can learn from it in the correct way.

    If the internal plantar flexing moment of the hallux exceeds or is equal to the external dorsiflexion moment created by the ground reaction force, the 1st MPJ will, to all intents and purposes be "blocked" In reality, it is just dislaying extremely high dorsiflexion stiffness. At every instantaneous point in the stance phase period of gait, that relationship could potentially be different.

    At the point at which the heel rises and the 1st MPJ is dorsiflexing, the external dorsiflexion force is exceeding the internal plantarflexion force at the hallux and FnHL cannot possibly exist.
    However, 1 millisecond later, due to a shift in centre of pressure or perhaps a shift in sub talar joint axis, the internal plantarflexion moment may be equal to the external dorsiflexion moment, again effectively "blocking" the hallux.
    Then, another millisecond later the opposite could happen and the external dorsiflexion force exceeds the internal plantarflexion force. This cycle could take place several times before we have even picked up a change in gross dorsiflexion movement at the hallux(theoretically)

    In a Jacks test, my goal is to simply get a feel for magnitude of the plantarflexion moments at the 1st MPJ. This will give me some type of clue in walking of the probable types of loads going through the central component of the plantar fascia. Is there a pathological amount of force. No, it is different for everyone. Eric can describe better than I many cases where 1st MPJ dorsiflexion stiffness is very low yet the patient has pronation related symtoms due to "active "pronation but that is another discussion.

    So, to go back to the original point, if we forget about FnHL (because it is a mechanical concept and not a diagnosis ) what are we really testing for. Is it indicative of pathological forces. No - in the same whay that supination resistance is not. However, it does give us potetntiallya an idea of plantar fascia load which, if it is clinically relevant can be some useful information to have

    Hope that made sense

    Robin
     
  12. efuller

    efuller MVP

    I think we have a semantics problem. What is your definition of function?

    You wrote:
    If you follow the above, you would conclude that no static measures will correlate with pathology. Following that to its logical conclusion you would say there is no point in doing static measures. I believe that we can find, and have found, static measures that will predict pathology.

    Eric
     
  13. efuller

    efuller MVP

    We need to examine your quote from Howard about the a few miliseconds of limitation of motion.
    I've had several e-mail conversations with Howard, and the miliseconds may not refer to hallux motion, but to a delay in "calcaneal unweighting" that can be seen when you measure the progression of the center of pressure. I believe this is the blockage of motion that Howard is talking about with sagittal plane blockade.

    My explanation of "delay" in calcaneal unweighting is different than Howard's. I beleive that Howard would say that the lack of hallux dorsiflexion will keep the weight back on the heel. My explanation is more behavioral. The subject has learned that ankle plantar flexion will increase internal forces on the hallux, mpj or fascia and chooses to use gastroc/soleus less and this prevents the forward shift in the center of pressure.

    Eric
     
  14. Petcu Daniel

    Petcu Daniel Well-Known Member

    It can be concluded that the definition of the mechanically concept of FnHl should not be based exclusively on the dynamically range of the hallux dorsiflexion but also on the proved (remains to see how !) alternative of a momentary "blocking" of the hallux after heel-off ?:confused:
    Sincerely,
    Daniel
    (I've learnt to make multiple quotes...could mean less boring posts !)
     
    Last edited: Jun 24, 2014
  15. DrBob

    DrBob Active Member

    Hi Eric and Daniel,

    To some extent there is a semantic factor. However, I believe it is very important because many people appear to confuse quasi dynamic measures (such as peak pressure, peak knee flexion etc) as being measures of function. They are not. They are measures made during function. To my mind function may be considered as a change of state? So you must have at least two measurements - one before and one after - that provide insight into something that happened during a specified time period (quite different to something which happens at a specific moment in time)?

    Yes, there are some static measurements that might give insight into function but, to my mind, that is like saying, body height can give insight into obesity (it might do if you rearrange the equation for Body Mass Index). This is not, however, the best way to find out about obesity, much better to measure what you want to know - measure their weight (mass)!

    So, I am not saying that static is wrong or pointless. I am saying that measuring the function directly would be the better way to find out about function. And it would have the extra benefit that it wouldn't cause people, like Daniel, so much brain ache through uncertainty.

    So, lets get some dynamic measurement methods, please.

    Regards,

    DB
     
  16. efuller

    efuller MVP

    I'm trying to get my head around this focus on dynamic measures. What we need are good measures. Measures that are preditictive of something that is important. I can make a case that peak plantar pressure in a particular location will be improtant for pathology. I'm making the distinction between pathology and function. I'm not sure why function is important, partly because it has a broad and vague definition.

    One problem I have with dynamic measures is that not every step is the same. Dr. Bob, you are calling for dynamic measures, but do you have any particular measures that you think are promising. I think we can find some static measures, like relative metatarsal length and STJ axis position, that will be predictive of pathology.

    Eric
     
  17. Petcu Daniel

    Petcu Daniel Well-Known Member

    Hi Bob,
    One important point for me is a practical one: very probable the majority of clinical settings doesn't have specialized devices to use for dynamic measurement methods. Which dynamic measurement should be employed in this case ?
    Second, a complete definition of a concept it is important for me because it could drive correct my way of thinking. In the case of FnHL , for example, if it is correct to think that it could exist even if the dynamically ROM of hallux is not reduced at the end of toe-off (but it could be a blockade in the propulsion phase), then it make sense for me what Robin has written here, and I'll look much more carefully at what information a static clinical test could give to me.

    Sincerely,
    Daniel
     
  18. Petcu Daniel

    Petcu Daniel Well-Known Member

    Hello,

    I've attached 2 images from one subject [1 trial and 5 trials, left foot ]. The clinical tests described in the articles mentioned in this thread is indicating to me a FnHl. Do you think that it is possible for the attached COP trajectory measured with a force platform to be a confirmation of FnHl ?

    Thanks,
    Daniel
     

    Attached Files:

  19. efuller

    efuller MVP

    What is missing from those pictures is anatomical landmarks and the relative timing of each mark. So, I can't be sure of what I'm about to say. I have looked at a lot of center of pressure plots. What those appear to show is a fairly average heel to toe step of someone walking left to right. On the left side of the graphs you see a clumping of the center of pressure points around the heel that occurs before forefoot contact. After forefoot contact, the average point of force will be pulled anteriorly as there is increasing load on the forefoot. After heel off there is usually a clumping of the center of pressure points under the metatarsal heads. In these plots there is either a medial or lateral shift of the center of pressure when the cop is under the metatarsal heads. Then, in the last few percentage points of the step the toes are in contact and the metatarsal heads are not in contact. In some feet it can appear to be random whether the first or 2nd toe is last one to have contact. It appears that the area you are pointing to is the clumping under the metatarsal heads. So, no this would appear not be the delay in calcaneal unweighting that Dananberg describes.

    If I recall correctly, the delay, that Dananberg describes, presents as slower progression of the center of pressure dots when the center of pressure is in between the heel and the forefoot.

    Hope this helps,
    Eric
     
  20. Dananberg

    Dananberg Active Member

    To specifically answer your question, can a foot which exhibits Functional hallux limitus (Fhl) have a ROM consistant with a foot without Fhl by the end of the step.

    The answer is yes, but the key to understanding this involves the time period when this motion occurs. During the gait cycle, there are two periods of support; single and double limb. When Fhl is present, ROM during single support may be completely absent, but when weight shifts to the contralateral limb as double support begins, motion can return to the trailing limb. This would make motion appear equal in the two different case scenarios by the end of the step, but these would vary significantly as to when movement actually took place.

    The key to understanding Fhl is not if there is ROM, but when.

    Howard
     
  21. DrBob

    DrBob Active Member

    Hi Daniel, Eric and Howard,
    I'm grateful that Howard has highlighted the crucial issue of time, which in my mind is key to understanding function (function/action/dynamic behaviour is a function of time). Eric, as I have said, I don't think there is anything wrong with looking at static predictors, but they are, and will always be, very limited. Ask an engineer if they should design an aeroplane without doing aerodynamic studies or a bottling machine without doing a vibration analysis and they would think you insane! Static will never be good enough for moving/functional things, especially if we want to understand sophisticated motion systems. Daniel, until we start measuring things in a dynamic (during function) way, we will not know what measures will be best for our needs...
    Regards,
    DB
     
  22. Petcu Daniel

    Petcu Daniel Well-Known Member

    A slower progression of COP could means a deceleration of COP. An AMTI force platform give as result only a maximum and average velocity of COP. Maybe we have need to calculate an instantaneous velocity or acceleration to see what happens.
    There is any article who attempt to make a correlation between FnHl and COP trajectory parameters ?
    Sincerely,
    Daniel
     
  23. efuller

    efuller MVP

    It's important to remember what causes changes in center of pressure. The center of pressure is altered by changes in muscular output. As the Hicks paper showed back in the 50's, Increase in Achilles tendon tension will shift the CoP anteriorly. Increase in tension in the peroneals will shift CoP medially and increase in the posterior tibial tendon will shift the CoP laterally. So, as we look at changes in the center of pressure path over time we have to think about whether the change is a purely mechanical effect, or a behavioral effect. A change in muscle output is a CNS mediated behavioral change.

    That said, a consistent behavioral change associated with FnHL would be an interesting thing to study and know about.

    Eric
     
  24. efuller

    efuller MVP

    If you asked an engineer if could solve, equally well, the problem that he is having with either a static measure or a dynamic measure, he would think you are insane if you chose the harder to get dynamic measure. The problem that we as clinicians have, is not understanding foot function, but relieving our patient's pain. I would agree that dynamic measures, like joint power, would be interesting and might help us solve clinical problems. However, I think I can do quite well when deciding whether or not to add a medial heel skive to my orthosis with the static measure of STJ axis location. I don't think that dynamically finding the axis is any better than statically finding the axis. So, I think your statement that "Static will never be good enough for moving/functional things" is wrong.

    Eric
     

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