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Role of the spring ligament

Discussion in 'Biomechanics, Sports and Foot orthoses' started by NewsBot, May 6, 2008.

  1. Mart

    Mart Well-Known Member

     
    Last edited: May 12, 2008
  2. David Smith

    David Smith Well-Known Member

    Kevin M

    Yes it is. Thats a fact.

    Tensegrity must be pure or perfect otherwise its not tensegrity it's just normal mechanical principles. Everything in construction works on the principle of tension and compression. There are no other states of a mass under load. Bending, shear and torsion are just special forms of compression and tension. The special feature of Tensegrity is that it has discontinuous compression, if this is violated then the structure is just a compression tension structure.

    .

    Yes! but with the greatest of respect, You see this because you allow violation of the tensegrity principle and so the principles of tension-compression structures fit very well. Tensegrity has no laws outside Newtonian mechanics it is just a special architectural structure that must obey some simple principles to exist. If those principles are compromised tensegrity fails to exist.

    Cheers Dave
     
  3. kevin miller

    kevin miller Active Member

    David,

    OK, now we are getting somewhere. Am I allowing violation of a principle? Tensional itegrities are just what you explained in your PF post. The sticking point is the "contact" of the compression units. we have already addressed that. Now, one might argue that the articular cartilage is no different than putting a shoe on the foot, the same amount of force is transferred. However, consider a few things for a moment and you may change her mind.
    1) Stephen Levin, the orthopedic surgeon who has been trying to explain Biotensegrity for a number of years, arthroscoped his knee and had the surgeon attempt to close the knee joint. For all the surgeon strength, he could not close the joint.
    2) Going back to a much earlier topic where you and Martin pointed out that structures within the body develop together producing a chicken -- egg situation when it comes to function or injury. We see this with articular cartilage, linking bone to the tensile structures. What would happen if we took the articular cartilage away? Based on Stephen Levin's work and also some of my own, we see a 3-dimensional modular compartment configuration of the collagenous structures around the cartilage. In other words we are not breaking any of the rules of Tensegrity mechanics.
    3) Cartilages is there to act like a rubber washer the between two compressive units. The articular cartilage does not have blood vessels, it is a very primitive cell, it requires mild compressive forces to nourish, great compressive forces tear it or compress the fluid out leaving vulnerable to chronic damage. When this occurs the bones do make contact.
    4) The rubber watcher functional of articular cartilage leaves the joint with the proper amount of mobility, whatever that is. Hypermobility almost invariably leads to arthritis of some sort. In the knee for example, a medial collateral ligament injury often leads to arthritis in close proximity.
    5) And lastly, the engineers who described Tensegrity mechanics created rules the fit their materials. They were trying to mimic what they saw in nature, they did not have and do not have the materials to do so. We do not have to fit Tensegrity rules per se, we have to uncover the proper rules for a biological system. After many hours of discussion with people who both wanted to understand Tensegrity and to think it is complete hogwash, the biggest concern always seems to be the noncontact of compressive surfaces. I am making the statement now that the compressive structures do not make contact under normal circumstances, that they are separated by articular cartilage which does not bear most of the weight itself. An impulse created at ground contact needs to make it to the spine as quickly as possible and then dissipate before it gets to the head. The impulses travel through all types of tissue obviously. The articular cartilage, full of water, dissipates the force readily as we see once the impulse reaches the spine, dissipating for a reaches C-1. The muscles and tendons and the fascial compartments that surround them are very tight and can act like a guitar string, transferring the force readily. In something that is a bit odd to wrap your mind around, the compartments that hold muscle, composed of fascia, act like water balloons- for lack of a better description. If there is not much water in the balloon, tapping in with your finger produce only a jiggle. If it is very full of water, it vibrates. If you can recall the amount of pressure within that fascial compartment you can see how the structures within the compartment itself transfer force better as a functional unit then as individual units. And on that note, a muscle group with high tone transverse force better than one with low tone. Obviously this can be good or bad, but the point is clear.

    I don't have any references on this as there are only a few people doing work in this area -- myself been one of them. I am simply reporting my discovery thus far as honestly as I can, and will release it for public scrutiny when I have finished collecting data. Three years ago I didn't know very much about Tensegrity, nor did I care. I learned about it while discussing with an Anatomy prof some of my findings. He said they sounded like tensegrity and that I should check it out..... and here I am.

    And from now on I guess we should write about this on the other thread. Is it up yet?

    Kevin Miller
     
  4. Mart

    Mart Well-Known Member

    .
    .

    This is an extraordianary anecdote, if I understand you correctly the implication is that there is no contact between the articulating surfaces of the knee?


    If I understand this correctly you are suggesting that the point of tissue contact within a joint, at a microscopic level, a sub system of mechanical linkages operates which distorts our perception of what is actually happening in terms of compressive force?

    This is an intersting contradiction to my notions of compressive forces within vertically aligned weight-bearing joints and sits interestingly aside another thread which talks about the effect of lateral posting on degenerative knee pain. What I do not understand is why there might suddenly be a change in compressional stress within the joint simple by removing the articular cartilage? The only consitent arguement is, as you I think alluded to, is that on a microscopic level the bone and cartilage have different mechanical organisation, I am not sure how you might test that idea.

    good point

    Turvey's paper explores the role of fascia in a similar light. I am getting more open minded once I start thinking at microscopic level. If I am understanding you correctly what I normally think of a compressive boundary may actually be acting as a tensile boundary. Just thinking out loud a bit. The visco-elastic characteristics of our load bearing structures are varied and that variation must be due to their different cellular mechanical alignment, or even as in the case of muscle to microscopic linear motors. So is it possible then that forces are transmitted through and around joints differently according to what separates them. Paul seems to suggest that the equilibrum between tensile loading and compressive loading is modulated by a mechanosensor feedback system.


    cheers

    Martin


    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  5. Stanley

    Stanley Well-Known Member

    Dave,

    A few months ago I had you rub the sides of a patient’s knee to see what would happen.
    If you remember, the patient was ecstatic.
    What exactly did you do? You were working on the fascia, which is a tensile element.

    I had a hard time understanding the concept of the bones not being in compression, until I realized that for a disc in the spine to bulge it would have to be under compression that was greater than it could handle. Add to this the powerlifter squatting 1000lbs, and realizing that he does not blow out his discs, and you realize that there has to be more than the simple disc bearing the weight theory. What is happening is that the bones are suspended in the fascia, and the muscles attach to the fascia to form the tensegrity structure.
    I only know little bits and pieces of it. For instance, you can try this. One of your patients this week will tell you that her knee hurts, and the MD wants to do surgery because of the arthritis. Go about 4-5 inches above the knee on the anterior medial aspect, and rub it downwards about 10 times with moderate pressure. You will know you have the right spot because it is exquisitely tender. Have her stand up and ask her about her knee.
    You can then explain to me why this works (but first start with you are seperating the joint).

    Regards,
    Stanley
     
  6. Stanley

    Stanley Well-Known Member

    Dave,

    I am not so sure that a rigid ligament could take the place of the plantar fascia. For standing it would be an improvement, but for walking, the plantar fascia stores energy from the prior parts of the gait cycle to efficiently assist with propulsion. I think you found in your research that there was more elasticity of the plantar fascia than you expected.

    Regards,

    Stanley
     
  7. musmed

    musmed Active Member

    Dear Martin

    What I wrote about the tenocytes etc has been discovered by Prof Khan who works somewhere in Canada. Maybe googling will find him. he is the co author of the famous book on sports injury with Dr Peter Brunkner from melbourne Aus.

    Regards
    Paul C
     
  8. musmed

    musmed Active Member

     
  9. kevin miller

    kevin miller Active Member

    Wow, we did morphintotensegrity central. At any rate, it really is not off topic. We were discussing the role of the spring ligament when I said that niether the spring lig nor the PT are the first to go. I said, in so many words, that the lateral column structures failed first, overloading the (tensegrity) system. The spring lig and PT fail because the calacneus plantar flexes and the lateral column deviated, stressing the spring lig and overloading a now-shutting-down-PT which does so to try and stop the individual from hurtig himself further. We take aleve and keep going.

    David suggested that I was not refereing to a tensegrity mechanism and I clarified by saying that I was, that we were just discussing a "unifunctional" part of the multifunctional system. Are good to this point?

    Kevin M
     
  10. kevin miller

    kevin miller Active Member

     
  11. Mart

    Mart Well-Known Member

    [/QUOTE]

    Yes . . . . .. nice allusion . . . . . .. . . but I add the rider that I am well inoculated against cultism (which is not to suggest that you are not also). The ideas (which perhaps needs better definition) seem to be regarded in this light by some as cultist. My problem is that I don’t have the knowledge to be able to take th idea apart logically, since it has tweaked my interest and I see value in at the minimum in filling some knowledge gaps. Hopefully we can explore this further on the other thread.

    If Kevin Kirby is reading this . . . . Please keep an eye on this because with your background in physiology, wonderful appreciation of biomechanics and massive scepticsm regarding a (quasi?) tensegrity model you are a perfect part of the discussion, I am not asking that you do my homework , just put a red mark and a question mark where needed. BTW Turvey’s paper covers many ideas and tensegrity is only a small part of what he is over viewing


    cheers

    Martin :drinks

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  12. kevin miller

    kevin miller Active Member

    My problem is that I don’t have the knowledge to be able to take th idea apart logically, since it has tweaked my interest and I see value in at the minimum in filling some knowledge gaps. Hopefully we can explore this further on the other thread.

    BTW Turvey’s paper covers many ideas and tensegrity is only a small part of what he is over viewing
    [/QUOTE]

    Martin,

    I really don't see any gap in your knowledge base. In fact, you are well equiped to discuss this topic. You also have done something that many do not.... open your mind a little to something that is different from what you have thought your entire career. There is little more, in essence, to biotensegrity theory than we have already discussed. As I said before, most of it is based on well understood neuromechanical processes. The other problem, that I hope we can address when we go over that monster papaer you have me reading with relish, is vocabulary and a common terminology. This is one place Kevin Kirby excells. It would be a great help if Dr Kirby could take some of the arcane terms used to describe tensegrity and bring it back to acceptable terminology. That, I think, would get rid of a lot of confusion and misconception.

    Cheers to all for having a great open discussion.

    Kevin M
     
  13. kevin miller

    kevin miller Active Member

    Martin,

    It looks like they pulled the original thread to the Turvey papaer because we did not answer right away. It took a day to read the paper!! Anyway, I started one up again and left comments you may want to read.

    Kevin
     
  14. Martin:

    I have been reading along but don't want to get into another discussion about "tensegrity". In many previous comments that I made on JISC Mailbase, I said that I believed that "tensegrity" and "biotensegrity" are interesting theories, but seem to not apply to the biomechanics of the human body given our current level of knowledge of its mechanics. The body is not a "tensegrity" system, using the definition of tensegrity given to us by the experts on the subject. Instead of wasting more of my time writing again why I think the believers in "biotensegrity" are wrong, I am copying some of my replies from the JISC Mailbase so you can see where I am coming from.

    I have attached an excellent article from Salathe and Arangio that doesn't need to use ambiguous terms such as "tensegrity" or "biotensegrity" to nicely explain how the tendons, muscles and ligaments all work together within the human foot to allow its normal function (Salathe EP, Arangio GA: A biomechanical model of the foot: The role of muscles, tendons and ligaments. J. Biomech. Engineering, 124:281-287, 2002).
     
  15. Mart

    Mart Well-Known Member


    OK . . . . .. . thanks Kevin I appreciate your reply and reference, I'll give it a read.

    cheers

    Martin
     
  16. Martin:

    You have the intellectual ability to digest this article and make sense of it, I am sure of this. Don't worry too much about the equations since they are not necessary to get a good idea of the model of the authors from their text and illustrations.

    You are well on the way, Martin, to becoming a "tissue stress engineer".......a title that I do not just bestow on anybody.....and a title that acknowledges the use of engineering principles to understand the internal forces that occur within the foot and lower extremity that cause the pathology which our patients present to us in our clinics on a daily basis.
     
  17. kevin miller

    kevin miller Active Member

    Kevin K.,

    Respectfully,

    I am not a "believer" in anything. There is no room for faith in science. I come to conclusions based on hard won factual data. I have repeatedly stated that the definitions you and others have used for tesnsegrity are not correct. As for the "experts" on tensegrity, I am one. Try me. Just because I don't agree witht the "experts" you don't agree with doesn't make me any less of one. In fact, of all of the "experts" I am aquainted with - and I am aquainted with the best of them, Levin in cluded, I am the only one who has done exptensive anatomical research and currently are doing clinical case studies to be followed by trials. Rather than dismiss me out of hand, why don't you try some of what you ask everyone else to do....listen and learn. As bright and educated as you are, there is still room for improvement. TThere is room for all of us. As scientist, the day we loose the ability to accept at least the premise of the impossible until it can be proven wrong, is the day we cease to be scientists.

    Respectfully,
    Kevin M
     
  18. David Smith

    David Smith Well-Known Member

    Paul

    You wrote
    When the foot is in full stance and because of frictional forces the PF can have tension in it without that tension being translated to the achilles tendon.

    and this
    Ye I believe this is pretty much what I said in a previous post when making the analogy of the PF as a muscle more than a ligament.Therefore it may be possible for the anterior and posterior muscles to work synergistically thru the common connective tissue of the Plantar fascia and via the windlass mechaism.

    I'm not sure what your point is Paul.

    Cheers dave
     
  19. Kevin Miller:

    Since you proclaim yourself to be an expert in tensegrity, please list all the articles and/or books you have written or lectures you have given on the subject of tensegrity.
     
  20. Why wait to be an expert, Simon?! Just say you know the experts, say you have done more research then the experts have, publish nothing to show that you have done the research, and then, finally, proclaim on an academic website that you are an expert in the subject. Certainly seems to work for some people!;)
     
  21. Craig Payne

    Craig Payne Moderator

    Articles:
    8
    Forget that Wikipedia definition of an expert. Back in the days before powerpoint, I had a slide that defined an expert as: "A person from out of town with a box of slides" ... you could always tell who the experts at a conference were - they walked around with a bx of slides! (now they have powerpoints on USB memory sticks and are not so obvious)
     
  22. Mart

    Mart Well-Known Member

    Hey . . . . . settle down in the cheap seats. How many of us have not been intoxicated by their enthusiasm or obsession, just ask your first girl friends . . . . the hangover is bad enough without being put in the stocks to boot.

    cheers :empathy:

    your peacemaking Canuck
    (even though we do bludgeon nice cuddly seals to death on the front pages of international colour tabloid magazines)

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  23. :D

    I heard that expert is derived from the original spelling ex-spurt. Ex, as in has been and spurt as in a drip under pressure. Fortunatly the only subjects i'm exspurt in are so obscure nobody ever asks!

    Hey Kevin (Miller)

    I have an open mind here. I am willing to learn. Thing is i'm still waiting for this stuff

    You posted in Jan 07.

    As well as the trials you have spoken of in this thread. You make a good point, don't just tell us, show us.

    I'm not sure i'd agree here. On that basis we would accept the premise of UFOs, the loch ness monster and even marigold paste reducing IM angles ;) none of which have yet been proven wrong! I'm not sure thats what a scientist is!

    In fact can you even prove a negative? Sorry i'm rambling now.

    If the proof is out there then in the oft used words of an irish friend of mine, shaw us da gads. Publish already!

    Regards
    Robert
    PS
    Mart
    :D
    :drinks
     
  24. David Smith

    David Smith Well-Known Member

    Stanley

    You wrote
    It was more than a few months ago and using the techniques you have kindly showed and discussed with me I have built a very nice technique to improve saggital plane progression and transverse alignment for my patients. The rubbing of joint ligaments and fascia seem to be an important part of this. To stay within my scope of practice as a podiatrist and because more proximal manipulations seem to require more expert application I restrict my technique to the knee and below.

    How does it work, by magic:dizzy: No seriously I'm not sure what the mechanism is but would hazard a guess that there is some kind of local stimualtion that is referred to more distal parts via the fascia and muscles to produce changes in muscle and fascia tonus. While this almost always happens proximal to distal eg from knee to foot it only occasionally happend distal to proximal. This as I said is probably due to lackof experience and expertise.

    I have no problem with the notion that muscle, ligament and fascia communicate tonus information and synergistically adjust accordingly. Can we imply Biotensegrity from that? not from my point of view.

    Chers Dave
     
  25. musmed

    musmed Active Member

    Dave
    May I ask, where do these frictional forces come from? if you are standing still, nothing is moving so I do not kown where friction comes into it.
    2 how are the anterior muscles ( I presume tib ant and common extensors) are connected through the common connective tissue.
    also I cannot see them working synergistically if the muscles you are talking about.

    Probably wrong but let me know.
    Paul C
     
  26. David Smith

    David Smith Well-Known Member

    Paul

    There is friction between the ground and the foot these allow vectors that are not just vertical. But thinking about it again, if just quiet standing is considered then vertical forces will still allow tension in the Plantar fascia without any transmission of tension into the Achillles tendon.


    When I say synergisticaly I mean they are functionaly synergistic. Traditionally the Anterior tib is antagonistic to the Gastroc soleous complex. However they are synergistic in terms of ataining the foot position or function required.
    Therefore the gastroc soleous complex and the anterior group of muscles are synergistic in the function of maintaining the required plantar fascia tension.

    [​IMG]

    Cheers Dave
     
  27. kevin miller

    kevin miller Active Member

    Kevin K.

    I humbly admit that I have only given 10-15 lectures on the subject. Perhaps more if you consider that I mentioned tensegrity in context. The latest to a group of proffesors and doctoral candidates at Auburn University. My written work, however copious, is not for public consumption as of yet. I am under contract and as much as I would love to simply attach it alll for everyone to read, I cannot.

    That said, what makes one an expert? Was Einstien an expert on relativity only AFTER his papers were published? (No I am not comparing myself to Einstein....simply making a point)

    What makes me an expert is that I have read and digested EVERYTHING writen about the subject, I have discussed it at length with the other experts like Levin and even Gracovetsky, and I have a number of years of research under my belt just on the subject. I challenge you to ask anyone who knows me....who has met me and seen my work...and ask them if I know what I am talking about. Further, I ask you to challenge me. And understand this. Part of doing the research is figuring out where others have got it a bit wrong, so when I dissagree with the mainstream and say that the articular cartilage acts like a washer and has transient conact, I didn't read someone else's work and come to that conclusion by interpreting like a glorified food critic. I did all the cut-downs and experiments myself. So don't expect me to quote what you read somewhere. But do expect me to be able to explain why I say what I say - as well I should.......if I am going to be an expert, as you suggest.

    By the way, What kind research project are you working on now?

    Cheers,
    Kevin M
     
  28. kevin miller

    kevin miller Active Member

    Hi David,

    I'm not sure I follow. Could you tell me your view of biotensegrity...briefly, of course. You certainly can't make total inference, but there is more than implication from my view point and I want to understand what makes us see this differently.

    As an aside, An aclaimed orthopedic surgeon came to spend the day with me yesterday. He came because his feet and back hurt and he couldn't get them well. His travel tine was 6 hours one way. When he got here, the whole idea of tensegrity and manipulative therapy seemed perposterous to him. He left here pain free and accepting of the subject. I realize that is anecdotal, but it happens all the time, so I think someone has given you a screwy idea of how biotensegrity works. It IS different from engineering tensegrity and most everything you write - as and explaination - I could use to explain it myself.

    Cheers,
    Kevin M
     
  29. Mart

    Mart Well-Known Member

    Dave.

    I agree that there is synergy at play here but wonder at what level (s) this is working at. I think that the level of control in a static weight-bearing foot which takes precedence is keeping the vertical vector of body COM within the bounds of the area of contact (balance), overriding this will be feedback suggesting injury in which case some compensatory mechanism will operate changing relative tissue stress or causing cessation of weight-bearing.

    Now you say

    I would anticipate that the synergy between Tib Ant and triceps is primarily directed at maintaining COM and that PF tension is more likely part of that, but possibly more of a “mechanical intelligence” level in that its role requires no neurological feedback control input other than protection from injury. My understanding is the idea of autosupport is describing exactly this level of synergy.

    Trying to integrate all of the degrees of freedom in less or even a single variable seems to me what Turvey’s paper is exploring, and whilst I see this as advantageous don’t have the chops to see how this might work.

    At risk of appearing completely out to lunch I have a bit of an idea, which when I consider it further, would like to talk about more in the other thread . . . .. but here the gist.

    Turvey, I think rightly points to inadequacy of our understanding of MSK coordination. He points to abstract and logically implied systems which may be in operation which might replace our existing models but, as far as I can see, doesn’t attempt to show how this might work. So . . . OK . . . this may be “science fiction”, but like a lot of science fiction it can contain very compelling and useful ideas. Good science comes FROM highly imaginative minds (rant over before I start) so our expectations at this point are to look for logical flaws and see if something can work (defense completed).

    Please see if you can see something below.

    I present a list of my presumptions from basic extending into areas of uncertainty within what I understand and need a bit of reality check.

    When we approach this problem of identifying a control system we are doing the following;

    Assuming that evolution has, by virtue of the uncompromising and ruthless effect of natural selection and passing on the information which that selection is operating on created in our bodies (in every structure in the universe) “mechanical intelligence”.

    So far our intelligence has developed a process to explore, understand and control this “force” which we call “science”, some believe that there may be some basic simple law which can explain everything if it is set loose and allowed to do its thing.

    To apply science we look for measurable variables and apply statistical methods to separate randomness from other causes of the relationships between the variables.

    Ideally we compare the effect of one single variable on another.

    In complex systems there are too many interrelated variables (degrees of freedom) to make clear deductions, to improve the situation we may try and reduce the variables to make things more manageable.

    To study variables we create an abstract measurement system to quantify them, without this we are stumped.

    There are likely things which we are unaware of, but may add confounding variables to the system we are studying (and possibly cause what we might regard as randomness).

    The question of synergy ideally would be investigated by identifying some parameter which encompasses many of the degrees of freedom which confound its study. In “science fiction” terms a unit of synergy would be invented.

    There seems a growing notion amongst different scientific disciplines that there may be a way of linking energy and matter in terms of “information” in other words everything in the universe is a manifestation of “information” and when energy and matter are moved from one form to another there is this a level at which they both represent the same thing.

    if you have the stomach check out this

    http://www.nous.org.uk/BFMAP.html

    or more specifically this

    http://www.nous.org.uk/info.html

    and this

    http://people.cornell.edu/pages/jag8/path.html

    "OK Martin do you really understand this gobble de gook "

    "of course not, but I understand its implications"

    " then go away and work on something which you do understand"

    "OK but I need to know which direction to be heading"

    "use a map stupid"

    " there is no map for this territory . . . . I'll try asking the natives who understand the lay of the land"


    Now is the time to crack a joke . . . ….

    pigs are flying, eyes rolling, I can see Simon staring over my shoulder screaming KISS
    but this is not a simple subject, perhaps as a podiatrist I am ill equipped to consider this problem, my mind is an escalating positive feedback loop


    ahh . . . . . . . .. . the wonders of a good pint of . . . .. . .

    The synergy which we may be trying to find may be tied in with this idea, this is purely intuition on my part and I cannot find any logical progression into it, may be crazy and if anyone is interested enough please put me out of my misery.

    Synergy is as far as I see it an interaction of information. The restraints to what might happen within the system are predetermined (effects of gravity, limits of tissue strength, durability and power, geometric relationships of structures (down to subatomic level), speed of conduction within the various elements of the nervous system etc) and may be regarded as the evolved “mechanical intelligence”, this has been the domain of biomechanics so far to probe.

    Perhaps I am misunderstanding Turvey’s paper, but in my, to date, limited comprehension of his paper, what he seems to be pointing to is considering the idea of finding a higher level of action.

    I feel after reading Turveys paper like I have been put through some kind of Zen Koan. This may be simply the effect on the mind of trying to comprehend a paradox; it either creates bliss (there is no question) or insanity (there is no answer).

    Please bite on this and spit it back if distasteful …and if you can find me out to lunch let me know and . . . . . .. . . I’ll see you at breakfast (if I am still sane).


    cheers

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
    Last edited: May 16, 2008
  30. kevin miller

    kevin miller Active Member

    Wow, Now we find out who is lurjking out there. I have absolutely no reason to NOT expect anything other than what I got in response to that post. On the other hand, it got the OTHER response I wanted as well. I really wish some of you would read the Turvey paper. It is the closest thing I have seen to explaining
    what I am talking about.....even without the Zen stuff. You don't have to go there. If you will got to our other thread on Turvey, you can have more fun with us AND read the paper.

    That said, in all seriousness, how hard is it for you to believe that I am one of the few doing deep research into this area? No one else seems to believe that a natural arrangement of mass and force defined by the laws of newton and possibly exist andd a state that they don not fully grasp. Just because I haven't published it doesn't mean it doesn't exists. I haven't even submitted it yet. It may be a year. I really wanted my doctorate finished fist. My masters is fine, but both would be better. In the meantime, I can't really write big bites of my material, but then neither do I want to sit completely idle without debate for the next years. I simply implore you all an open mind and I'll return fair debate. But as you arleady know, we are short on references in this area. I have the most extensive basic anatony material on it (that I know of).

    Cheers,
    Kevin M p.s. keep 'em comin" :drinks
     
  31. Mart

    Mart Well-Known Member


    Hi Kevin

    As you may appreciate I have intentionally tried to expose a bit of my personality in my posts on this thread and tried to add a bit of intelligent humor to try and defuse what I perceived as destructive tension. I hope I have made it clear that I have no particular axe to grind but feel sensitive to the value of this forum and what people expectations (rightly) are.

    I am no academic but I think I understand what academia does and demands.

    Those that dedicate a large part of their lives to “finding the truths” have created some expectations in terms of how ideas are presented, they do most of the work in keeping this "accedemic" forum healthy and I suspect they do not want to see its value diluted.

    You have to earn respect (they already did that) not demand it (you tried to).

    There is a bit of a grey zone which borders acceptable and unacceptable and having hung around this site for a few years, I feel like I know what that is and respect a reasonable tolerance to those of us to veer into that space.

    With no intention of insulting you I feel that the scorn which fell on some of your comments was justified, but also that it would be a real shame if that resulted in what I see as the downside of out egos – escalating destructive tension. I recognise a restless and turbulent mind (like my own) full of ideas but which has, within the context of this forum, an unfortunate way of expressing them and which maybe would benefit a bit of conforming to “the rules”.

    I made this post public when perhaps I should have made it personal because I think it illustrates a problem which occurs time and again with internet communication between people who have never met and can be a waste of good possibilities. I get the impression that main protagonists of this forum have dedicated their lives to what they comment on which created opportunity to meet face to face and know each other quite well which changes dynamics. I have not met anyone on the forum, and dedicated my life to earning enough money to pay for my lambergini and support my 3 trophy wives.

    Apologies to those who see no place for this post, it was quite presumptive of me to take on this role (perhaps I should get out more often). Kevin, if you feel inclined to take issue with what I just said please email me "off" the forum and we can mull it over further and let everyone else get on with the original thread.

    Enough of this touchy feely stuff, I need to go take a pill

    cheers :drinks

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
    Last edited: May 16, 2008
  32. kevin miller

    kevin miller Active Member


    Robert, for the record, the MRI stuff I spoke of in Jan was done by someone else. I don't think he minds anyone looking at that data, I'll ask him. As for my work, I know you understand a multi-year project. I have just been throwing out bits of stuff I have learned the past 3 years. I am getting closer to submission, however, and I promise that as soon as I can I will release all of my work on this site. Early on, I would get a bit self conscious when I drew ire, but now that I have seen the same things over and over again in my work, I simply am biding my time until I can show folks like you.

    Thanks you very much,
    Kevin M
     
  33. Kevin Miller:

    Until you can somehow show me that the joints of the foot and lower extremity are not subjected to compression forces so that the compression elements of the foot and lower extremity (i.e. bones) do not interact with other bones via compression forces, or exhibit "discontinuous compression", as described within the definition of tensegrity , then I will not believe that tensegrity can be used to usefully describe the function of the foot and lower extremity. When you get your PhD, and the subject of your doctoral thesis is on tensegrity, then I will consider you an expert on the subject of tensegrity. I won't be holding my breath. :rolleyes:

    By the way, self-proclaimed experts don't impress me or many others since real experts don't need to proclaim they are experts. Real experts always have plenty of others that are gladly willing to give them that that title, without ever needing to proclaim their own greatness.
     
  34. kevin miller

    kevin miller Active Member

    Kevin K.

    When you wrote the above, had made no such comment. I merely agreed with you after the fact to see what you would do, which was pedictable.
     
  35. kevin miller

    kevin miller Active Member

    Why is it you cling to things like a Wikepedia difinition of Tensegrity when we are talking about biotensegrity? I have said repeatedly that the engineers and artists who use tensegrity say that they are copying nature. They neither have the materials or the understanding to recreate biotensegrity. The fellow who coined the word - Kenneth Snelson - never said that nature looked like his work, he said his work looked LIKE nature. The point is, that engineering principles will nevere totally fit nature.

    I have explained twice now and Paul once how dicontinous compression occurs.

    By the way, as lomg as I go completely against the grain, I will in no manner have anyone proclaiming me an expert. Besides, see my previous post on this matter. And lastly, I don't think I am great, I just work hard and would like to run ideas past people who will discuss them rather thanact like I have done something fould in their cornflakes. Disagreement I can understand, but you responses border on vitriol.

    Kevin M
     
  36. Kevin M
    I suspect i am not the only person here who would benifit from a brief read of YOUR definition of bio-tensegrity.

    It has probably been posted before in which case a link to that page will be fine!

    Its a long running debate and a lot of folk will be coming in half way and wondering what the hell you and KK are arguing about!:confused:

    Much ta
    Robert
     
  37. musmed

    musmed Active Member

    Mate

    I am not going places, but... you proclaimed in 2005 at The UK summer school" that bow legged people of which you are one, run faster.

    There was a Rock band in Australia called Midnight Oil. The lead singer Peter Garret is now a politician.

    he had a song and there was a line in it " short term memory my fellow man"...
    Applies here.

    Stop just believing in what you believe and open your eyes.

    Just have a look at the links to how cellular tensegrity works. If it works at a cellular level why in the hell does it not work in the foot! ie macro level?

    I am just sitting on the fence, but have a good memory of what you said at that workshop....

    If you want to get nasty, That's fine, but what I have written you said and I can get several others that were there to back me up.

    Now who is the expert?

    Just stick to being nice.

    Remember that Sir William Harvey was to be burnt at the stake for describing circulation. He took protection in a church just around the corner from the Tower of london and in Durham cathedral near Newcastle on Tine. His name is inscribed on the roll of honour there.

    Just a friendly reminder for all.

    Paul Conneely
    ww.musmed.com.au
     
  38. musmed

    musmed Active Member

    Dave

    I am sorry but i do not agree with you. Your diagram has the great toe bent up. I certainly do not do this when I stand still.

    When I examine patients, if I see any activity of the Tibialis Anterior within 1 minute of standing still after they take six marching steps on the spot with their eyes closed and then open then as a dysfunction somehwere.
    I believe that there shoud be no activity here for at least 1 minute after stopping motion.

    Regards
    Paul Conneely
    www.musmed.com.au
     
  39. David Smith

    David Smith Well-Known Member

    Kevin M

    You wrote
    My view is it (biotensegrity) does not exist in terms of pure tensegrity as defined by Flemmons TE 2007

    A tensegrity (structure) requires at minimum three conditions to fit either Kenneth Snelson's or Buckminster Fuller's definition.

    1. A continuous connective tensioned network supports discontinuous compression struts. Snelson insists that struts must be free floating in a web of tension and not touching. A geodesic dome, which Fuller considers to be tensegrities, has multiple compression struts meeting at central hubs but they are discontinuously connected, that is, they do not transfer compressive loads. In these domes it is the tension forces that travel along the outer edges of the struts that are continuous. Similarly, if anatomical structures operate as tensegrities, then in most orientations the bones do not pass a direct load across the joint– rather the tension members; ligaments, tendons, and fascia transfer loads and the bones float in this tension matrix.

    2) All tensegrities are prestressed under tension; they are self–supporting and independent of gravity. But the weight of the structure also adds to the prestress. As you increase the weight load the tensegrity tightens and gets smaller. The heavier the structure is, the greater the tension, and the less the range of motion. This presents real design problems when trying to model living systems that have and use joints with multiple degrees of freedom. My models for example can emulate biologic movement because I use elastic tension nets that are taut enough to maintain the shape of the model yet have enough residual elasticity to move through a wide range of positions. When the size and weight of a model increases, so does the prestress. It is always surprising to discover how high the tension levels climb when building large tensegrity structures. In some of Snelson’s largest sculptures (50’–100’) the tensile cables carry thousands of pounds of force. To make human scale tensegrity models that articulate and are prestressed is not a trivial challenge.

    3) Tensegrities are self–contained non–redundant whole systems. All components are dynamically linked such that forces are translated instantly everywhere; a change in one part is reflected throughout. These features distinguish tensegrities from all other tension structures, e.g. a radio mast or a sailboat’s mast is fixed at the base and needs that fixed point to keep it upright. The boat does not need the mast for it’s integrity but the reverse is not true. Every part in a tensegrity is reliant on the entire structure for its continued existence. In terms of living forms, a discontinuity in a structure marks the boundary or interface between separate tensegrities. Also, molecules within cells within tissues within organs within bodies, and bodies within environments are all synergistically linked tensegrities in a hierarchical cascade from the smallest wholes to the largest


    Flemmons, while aknowledging the possibilities of biotensegrity also points out the limitations of the reality.

    Like I said I am comfortable with the notion of interconnected synergies of the anatomy and clearly redundancy as a theme runs through out the musculo-skeletal system. Theses synergies are most likely to be reactive and proactive and fortunately (in terms of evaluation) common activities have common muscle actions to control joint excursions and effect the velocity and magnitude of limb and joint displacement. Even tho it appears that these synergies exist it is not so clear that they are universally and instantly communicated thru the entire body.
    I believe the cascade of synergism may be more hierarchical in that the larger the displacement and the more important it is to stability and balance the more far reaching the cascade. There may also be a time element where the longer the displacement the more far reaching the reactive cascade may eventually be.
    It would appear to me that this is the only way a functioning biological mechanism could conserve its integrity.

    We as humans have not yet come close to constructing a mechanism that has the sophistication of a biological organism and tensegrity structure have not, as far as I know, increased our ability to do so. As far as I know there are no mechanisms that incorporate tensegrity into its design. Especially where that design includes the joint mechanisms that must have wide and varied range of motion available.

    As I have said before Kevin if your definition of Biotensegrity allows violation of the three principles above insomuch as continuous compression can me allowed and that joints do have compresive forces and are not entirely floating i a triangular tension system and that there is redundancy in the biological system and that any pertubance in the system does not necessarily transmit thru the whole biological system then I can agree that there is Biotensegrity in terms of those definitions.

    I can also agree that a swan is a duck as long as you allow violation of the definition of a swan to include that it can be much smaller, has lots of coloured plumage has yellow chicks and quacks.

    If your definition of Biotensegrity is that it is a system of hierarchical structures from the microscopic to the macroscopic and from the individual tissue to the entire musculo-skeletal system and that each component and that whole structure relies on the mutual integrity of both. Then I also can agree with this.

    This next paper has set out very clearly its definitions and uses accepted mechanical explanations.

    Chen C and Ingber D Osteoarthritis and Cartilage (1999) 7, 81–94
    Tensegrity and mechanoregulation: from skeleton to cytoskeleton
    Appear to follow this definition.

    Summary
    Objective: To elucidate how mechanical stresses that are applied to the whole organism are transmitted to individual
    cells and transduced into a biochemical response.
    Design: In this article, we describe fundamental design principles that are used to stabilize the musculoskeletal
    system at many di#erent size scales and show that these design features are embodied in one particular form of
    architecture that is known as tensegrity.
    Results: Tensegrity structures are characterized by use of continuous tension and local compression; architecture,
    prestress (internal stress prior to application of external force), and triangulation play the most critical roles in terms
    of determining their mechanical stability. In living organisms, use of a hierarchy of tensegrity networks both optimizes
    structural e$ciency and provides a mechanism to mechanically couple the parts with the whole: mechanical stresses
    applied at the macroscale result in structural rearrangements at the cell and molecular level.
    Conclusion: Due to use of tensegrity architecture, mechanical stress is concentrated and focused on signal
    transducing molecules that physically associate with cell surface molecules that anchor cells to extracellular matrix,
    such as integrins, and with load-bearing elements within the internal cytoskeleton and nucleus. Mechanochemical
    transduction may then proceed through local stress-dependent changes in molecular mechanics, thermodynamics, and
    kinetics within the cell. In this manner, the entire cellular response to stress may be orchestrated and tuned by altering
    the prestress in the cell, just as changing muscular tone can alter mechanical stability and structural coordination
    throughout the whole musculoskeletal system.


    Later in more detail they say

    The stable position of the bones that articulate
    at any joint depends on the tensile forces of the
    muscles, tendons, and ligaments that bridge them.
    In the knee, for example, the cartilagenous regions
    at the end of apposing bones come into direct
    contact due to compression (Fig. 1). Most of this
    compression is not due to gravity, rather it is
    created by the surrounding ligaments and tendons
    that crosses the joint, and these are always under
    tension. The internal tension and/or pre-stress in
    this system stabilizes the joint: even when the
    bones are pulled away from each other (e.g., hanging
    upside down), the joint does not dislocate. In
    reality, there are multiple muscles, tendons, and
    ligaments that contribute to the structure of each
    joint and the number and position of these tensile
    elements (i.e., the architectural arrangement) play
    a critical role in defining the joint’s potential
    strength, power, speed, and range of motion. To
    understand the critical importance of these internal
    tensions and/or pre-stress in this complex
    structure, one only needs to examine the case
    where tendons and ligaments loosen: this results
    in joint instability, increased wear on the articular
    cartilage, pain, and loss of function


    But clearly they allow joint compression which would indicate non floating struts and continuous compression. Which violates Flemmon and Snellon and Buckminster Fuller's definition. Is your definition more inline with that of Chen et al?

    and they elaborate on this

    The tensegrity structures are constructed by
    interconnecting a set of isolated compression
    struts with a continuous series of tension wires
    that pull the struts up against the force of gravity
    and stabilize them in an open array (Fig. 5 top).
    These simple structures are the most striking
    examples of tensegrity and clearly visualize its
    basic mechanism of self-stabilization. However,
    structures do not have to contain isolated struts
    and wires to be defined as tensegrity structures.
    Rather, it is how a structure distributes stresses to
    establish a force balance and stabilize itself
    against shape distortion that defines tensegrity.


    DO NOT HAVE TO HAVE DISCONTINUOUS COMPRESSION (weakening the definition)

    At the end of the day we are really not a million miles apart its just a matter of definition. Once you can accept that tensegrity in the loose terms that are defined by Chen and I suspect you Kevin then you will also accept that it is merely an extension of normal mechanical structure but far more sophisticated than man can build. This confounds our ability to characterise, analyse and evaluste the mechanism even tho we may have a firm grasp of the principle of operation. As Martin has said there are many degress of freedom in terms of the variables and the ability to test caustation and not just correlation. I believe when you accept this you will be able to present your well researched theories in a manner more acceptable to the establishment.

    Since every loaded structure is in a state of compression and tension and only tension and compression, the term tensegrity becomes redundant when not refering to a rigorous definition of discontinuous compression in a triangular tension system. Perhasp a name like Synergistic Hierarchical Bio Mechanism (SHBoM :cool:) would be more decriptive and accurate. We all knew this anyway (i believe) but we just haven't given the system a formal name.:boxing:

    All the best Dave
     
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