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Plantar fascia, windlass and all things fore and aft!

Discussion in 'Biomechanics, Sports and Foot orthoses' started by toomoon, Mar 12, 2013.

  1. toomoon

    toomoon Well-Known Member


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    I have been asked this question via my website, and thought it interesting enough to post on PA to get a spread of opinion. The questioner is currently a Masters student in Anatomy at the University of Capetown, and his name is Max.

    "You say on your website that the Windlass mechanism is the "holy grail" of technical footwear design.
    As my current thesis at UCT is focusing on the insertions of tibialis posterior, I was wondering if you wouldn't mind enlightening me on the relationship between TP and the Windlass mechanism.
    The reason I ask is because of the obvious interdependence of the Plantar fascia, TP, peroneus longus, flexor digitorum longus, and flexor hallucis longus, as well as the various intrinsic ligamentous structures.
    According to the study I have referenced below, excessive pronation resulting from inadequate TP function (although it is not clear which comes first; inadequate TP results in excessive pronation, or excessive pronation diminishes TP function) and thus elongation of the plantar fascia occurs.
    Have you found this lengthening of the PF to actually occur? Likewise, could one argue that due to the resulting diminished efficiency of the Windlass mechanism that the supporting muscle, flexor hallucis longus, is thereby overworked? And because of the increased load on FHL (and I'm making this jump without too much reading into the topic), could the oft-diagnosed distal tibial 'stress fractures' be a result of wear and tear on the tendon of FHL (and not TP, as many clinicians say). My logic here is that in the mechanics of foot strike, the hallux is the 'power toe' that produces the force at toe-off, and with a dysfunctional TP or Windlass mechanism or both, FHL is over-worked in its duties to generate this force.
    Any insight you could provide to help organize my thoughts would be greatly appreciated, I apologize if I come off like I'm rambling! Cheers, Max

    Source: Bolga, Lori A. and Malone, Terry R. "Plantar Fasciitis and the Windlass Mechanism: A Biomechanical Link to Clinical Practice." Journal of Athletic Training. 2004."


    For those of you who have not read this paper, here is the abstract
    Abstract
    Objective: Plantar fasciitis is a prevalent problem, with limited consensus among clinicians regarding the most effective treatment. The purpose of this literature review is to provide a systematic approach to the treatment of plantar fasciitis based on the windlass mechanism model. Data Sources: We searched MEDLINE, SPORT Discus, and CINAHL from 1966 to 2003 using the key words plantar fasciitis, windlass mechanism, pronation, heel pain, and heel spur. Data Synthesis: We offer a biomechanical application for the evaluation and treatment of plantar fasciitis based on a review of the literature for the windlass mechanism model. This model provides a means for describing plantar fasciitis conditions such that clinicians can formulate a potential causal relationship between the conditions and their treatments. Conclusions/Recommendations: Clinicians' understanding of the biomechanical causes of plantar fasciitis should guide the decision-making process concerning the evaluation and treatment of heel pain. Use of this approach may improve clinical outcomes because intervention does not merely treat physical symptoms but actively addresses the influences that resulted in the condition. Principles from this approach might also provide a basis for future research investigating the efficacy of plantar fascia treatment.
     
  2. A couple of quick points twixt patients: windlass mechanism occurs at all toes not just hallux; mtpj's are power absorbers, not generators during propulsion.
     
  3. Admin2

    Admin2 Administrator Staff Member

  4. efuller

    efuller MVP


    Both structures create a supination moment at the STJ. If one stops creating supionation moment then the chances are high that the other will have increased stress.



    Depends what you mean by interdependence. Yes, they are working on the foot but some have synergistic effects and others not. The interdependence is not "obvious". Peroneus longus is a complex muscle.




    Tell Max he should read Kevin's rotational equilibrium paper and my paper on the windlass and my paper on center of pressure and it's relationship to pathology. That should give him a good starting point.

    Eric Fuller
     
  5. bruk

    bruk Member

    I can't imagine that excessive pronation is ever due soley to a dysfunctional tibialis posterior. The TP is obviously a structure that contributes to the supination moment, but it is merely one of a myriad of synergistic muscles throughout the lower kinetic chain that contributes to this moment, and it's a small one at that. We can follow the "supination moment" via the windlass mechanism all the way up to at least the hip directly, and indirectly up to the occiput. I would argue that the most powerful supinator is actually the gluteus maximus.
    If we keep our perspective isolated to the shank and distal structures, the tibialis anterior is a more powerful, eccentric supinator than TP during the loading response of the gait cycle, which is where most pronation problems are initiated.

    Relating to the article regarding heel pain and the structures of the windlass mechanism, it was assumed that heel pain is from plantar fascitis. I see many misdiagnosed cases of heel pain as plantar fascitis, when in fact they are related to strains of the abductor hallucis at it's origin, and/or nerve entrapment between AH and quadratus plantae.
     
  6. blumley

    blumley Active Member

    Hi Eric if you have a copy of those papers or links to them could you put them on here or email them to me (benl101@hotmail.co.uk). Really interested in reading these as the rotational equilibrium paper is only briefly mentioned as part of our under graduate training

    kind regards

    Ben
     
  7. Andrew Ayres

    Andrew Ayres Active Member

    I to would be interested in a copy of your papers Eric. If thats possible.

    Thanks

    Andy
     
  8. Bruk:

    No, you are wrong. The posterior tibial muscle is the strongest supinator of the subtalar joint (STJ) since it has the longest STJ supination moment arm.

    We also know that when the posterior tibial muscle's tendon is damaged, a more pronated foot gradually or rapidly develops, a condition called posterior tibial tendon dysfunction (Mueller TJ: Acquired flatfoot secondary to tibialis posterior dysfunction: biomechanical aspects. J. Foot Surgery, 30:2-11, 1991). The development of pes planovalgus deformity with a reduction in ability for the posterior tibial muscle to provide internal STJ supination moment should be proof enough for any reasonable clinician to realize the posterior tibial muscle, even though it is not the only supinator of the STJ, is certainly not "a small" supinator of the STJ, as you claim.
     

  9. As Eric stated, the following references are vital to understanding the important biomechanical interrelationships between the posterior tibial muscle and the plantar fascia:

    These papers are all available for download on my website:

    http://www.box.net/shared/z9vvdj6lt8

    You may e-mail me privately for the password to my website.

    Simon, you may have Max contact me privately for access to these papers.
     
  10. OK, Bruk. Now you have me even more interested. Please send us a video of your own foot, non-weightbearing (i.e. off the ground) and using your own gluteus maximus muscle to supinate your own foot. We anxiously await to see how the gluteus maximus muscle is "the most powerful supinator" of the foot. Should be a great video.:cool:
     
  11. Bruk:

    I'm still anxiously awaiting how to hear how the gluteus maximus is a stronger supinator of the subtalar joint than the posterior tibial muscle. If Bruk is unable to explain this to me and the others following along, then possibly the "thankers", David Singleton and Ian Linane can explain this odd concept to all of us???
     
  12. Ian Linane

    Ian Linane Well-Known Member

    Hi Kevin
    I would hate to think I have contributed to your anxiety state. :D

    In addition to the supinator aspect Bruk made a number of comments in his post. The thanks button only allows a hit on the whole post.

    My thanks was in relation to, and a confirmation that in treating many of the plantar fascial issues that are either self referred or, more usually the case, are referred to me as plantar fasciitis, turn out to have more abductor hallucis involvement than straight forward Plantar Fascial involvement.


    I hope you can rest a little easier now :)
     
  13. Ian:

    Do you also believe, as does Bruk, that the posterior tibial muscle is not a strong supinator of the STJ and that the gluteus maximus is a strong supinator of the STJ?

    What gives me anxiety?.... when unbelievable comments about foot biomechanics are made in a posting here on Podiatry Arena and

    1) it is "thanked" by two people

    2) I am the only one who has commented on the absurdity of the posting.:bang::craig:

     
  14. Ian Linane

    Ian Linane Well-Known Member

    Hi Kevin

    I cannot speak for Bruk and perhaps Bruk will respond to your quite reasonable request, even if it is to say they cannot support their opinion with research.

    However, on reading Bruk's post it was obvious Bruk made a number of statement type comments on a very broad and large area (gluteal down to foot mechanics) in a single paragraph which could have benefited from being broken down and expanded upon by them, in order that readers might have a better idea of Bruks rational behind the comment. Giving Bruk the benefit of the doubt, at the point of reading the post, (I do not know them nor recollect, of note, reading anything else by them) my suspicion was that Bruk has fired this off as a general shoot both barrels of personal opinion rather than having expressed themselves more fully and cogently.

    Certainly been guilty of that myself on here before now and have been bruised for it. Hope I am impoving in that area over the years. To that extent I either:

    1. Generally allow latitude when someone makes such broad sweeping comment, whether I agree with them or not

    and

    2 Do so on the basis some battles are not worth my energy expenditure and choose not to become involved with them. Challenging Bruks large and broad ranging biomechanical opinion in their above post, in this instance, is one such battle.


    Similarly Kevin, in response to your fair and reasonable earlier question I explained my reason for thanking Bruk i.e. in relation to the plantar fascial/abductor hallucis matter.

    To that extent:

    "What gives me anxiety?.... when unbelievable comments about foot biomechanics are made in a posting here on Podiatry Arena and

    1) it is "thanked" by two people"

    In light of my explanation I have to disagree that I thanked Bruk for their biomechanical opinion and would appreciate acknowledgement of that.

    I am sure that people hit the thank button in many posts not for the whole content of that post but because there was one thing with which they agreed or there was a single insight in post that aided them, even if sometimes much of physics or mechanics content of that post might be above their heads. Certainly the case for me.

    As to the question you ask:

    "Ian:

    Do you also believe, as does Bruk, that the posterior tibial muscle is not a strong supinator of the STJ and that the gluteus maximus is a strong supinator of the STJ?"


    No I do not agree nor, so far as I can recollect, have ever intimated such a view in any of my posts (but been on here a few years so who knows?).
     
  15. Rob Kidd

    Rob Kidd Well-Known Member

    I take you point Ian (re: only one who has replied); I also take you point Kevin - re: some battles are simply not worth fighting. This is one of those. It is like fighting the creationists - eventually, you run out of steam and simply cannot be bothered trying to have a rational argument with irrational people. as for G. Max being a S/T supinator - well, I weigh 9 stone. Oddly I taught the Gluteals this morning to a secodf year group in pod school; GM is lots of things, and is a highly evolved structure in Homo sapiens, but subtalar supination is not among its qualities. Rob
     
  16. BEN-HUR

    BEN-HUR Well-Known Member

    Ahhh, no... you evidently ran out of evidence/reason/logic to answer what were/are simple legitimate questions... which should invoke simple/easy answers for one as well versed on such matters as you (apparently...going by your signature).

    If you continue to stir the pot on this issue Rob, I will continue to add the ingredients. Yet alas... I too... "simply cannot be bothered trying to have a rational argument with irrational people." [There, we agree on that sentiment... it's really rather ironic.]

    How about just sticking to the topic/questions at hand... with the empirical evidence (i.e. the anatomy/physiology).


    Hmmm... naturally one would think that (within an evolution paradigm) going by the size of GM (i.e. comparably small non-bipedal GM) evident in primates today... & which was also still present way back with some fanciful hominid ancestry candidate (trying to stand upright... walk... then run... & really work that foot windlass... amongst other things i.e. GM).
     
  17. Rob:

    As long as my health is good and I have the interest, I will continue fighting toward getting podiatry more properly aligned with the scientific community, especially in regards to foot and lower extremity biomechanics. Thanks for your comments.:drinks
     
  18. David Singleton

    David Singleton Active Member

    Ditto for me Ian thanks for doing that! :drinks
     
  19. Rob Kidd

    Rob Kidd Well-Known Member


    I rest my case..................... Rob
     
  20. BEN-HUR

    BEN-HUR Well-Known Member

    The Posterior Tibial (or Tib. Post.) muscle is certainly a strong (influential) supinator of the foot; as stated, we only have to see the ramifications of Post. Tib. Dysfunction (PTTD) on the foot to realise its involvement (i.e. adult-acquired flat foot deformity) - albeit, I do question what is the usual primary causes behind PTTD (& subsequent adult-acquired flat foot deformity). Is it the ongoing degree of pronatory forces/familial Pes Planus/pathology to the tendon (i.e. RA, Diabetes)/direct trauma/combination of either? Could this condition be seen as a "chicken or the egg" scenario (???)... just thinking out loud :)butcher:). Anyway, one certainly can't say that Post. Tib. is a "small" supinator.

    The Gluteus Maximus (GM) is evidently a powerful thigh/Femur extender... as well being an abductor/lateral rotator/external rotator - maybe it is this lateral/external rotator aspect which has confused Bruk with the "synergistic" "strong" supinatory claim (???). Anyway, the GM is very important in keeping us humans upright & erect as well as supporting single standing limb - hence its importance in bipedalism locomotion (unlike a primate - extinct or present).

    Yes, I resonate with the above also.

    Appears to be true in some areas... Lenin was onto something.


    I feel Podiatry is fairly well aligned with the scientific community - we've just have to make sure it continues to stay there & continue to progress in the right direction... abiding by empirical science/research & investigating hypotheses of which avoid violating known natural laws & principles.

    Yes, I likewise. Be it known, I still value your opinion & find your views interesting (I just may not agree with the premise/direction some of them come from... as well as the superfluous pot shots directed towards those of a certain "Origins" persuasion).

    Now back to the Plantar Fascia/Windlass mechanism.

    Matt.
     
  21. Rob Kidd

    Rob Kidd Well-Known Member

    I rest my case - again............................
     
  22. BEN-HUR

    BEN-HUR Well-Known Member

    Yes, I rest my case - again! Like I said, "I still value your opinion & find your views interesting" as the above content of post (lack thereof) speaks volumes to me (as has in the past... & little doubt will be the case in future).
     
  23. JasonR

    JasonR Member

    Hi All
    I wonder if Bruk was alluding to the flow of power in gait? Craig P has talked about the Bellchamber study which seemed to demonstrate that the hip 'drove' tibial rotation in walking and running, rather than the foot drive the tibia. I also found Craigs (Bootcamp) speculation interesting re the possible interaction between lack of power flow from the foot (a power sink??) and the capacity or otherwise of the leg to drive gait (OK he might explain it better).
    Jason
     
  24. efuller

    efuller MVP

    If I recall the study correctly, what it looked at was power flow from the lower leg to the foot. When you examine power, you know that the leg is driving the foot, but you can't say which structures of the leg is/are driving the foot. (Actually at heel contact there was a small amount of power flow from the foot to the leg that makes sense if you believe that ground reaction force causes STJ pronation at contact in gait.) So, the energy transfer, later in gait, could be from the posterior tibial muscle.

    Thinking about those power flow diagrams made me realize another thing. The windlass mechanism does not cause the resupination. If it did the power should be from the foot to the leg.

    Eric
     
  25. JasonR

    JasonR Member

    Thank Eric
    Is that supported by the fact that the MTPs are energy absorbers?
    Jason
     
  26. efuller

    efuller MVP

    I'm not totally sure, but I think that energy flow at the MPJ's are a separate issue from energy flow at the STJ or ankle joints. Power is moment x angular velocity. When the moment and the velocity there is an increase in change in energy is positive and when the velocity and moment are opposite energy is absorbed. At the toes, there is a dorsiflexion motion of the toes when there is a plantarflexion moment applied by the toes by the foot.

    Eric
     
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