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Macro Dynamic Biomechanics

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Tensegrity, Aug 25, 2011.

  1. Tensegrity

    Tensegrity Active Member

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    Hi Folks broke off the posts from Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery? for you, Mike

    Here's hoping your research position has a good set of parameters.
    In my experience the number of variables are very high and there are very few instances where it is easy to directly compare cases due to the unique nature of most of our lives.
    Surgery addresses obvious gross mis-alignments but does nothing to address the underlying musculo-skeletal issues that are there with chronic conditions.
    Macro dynamic biomechanics looks at how movement occurs through out the body and hinges on the patient taking responsibility gor their body.
    Simply taking a cast of the foot and creating an orthotic captures a point in time but does nothing to resolve the timing issues that a present.
    Good luck with your research
  2. Griff

    Griff Moderator

    Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?


    Actually, changing temporal patterns (of reaction forces at the foot-orthosis interface) is exactly one of the ways that foot orthoses can and do work.
  3. Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    look at it, say what it is....
  4. Tensegrity

    Tensegrity Active Member

    Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    An orthosis can not correct for an incorrect heel strike. In some instances it can lessen the affects of a poor heel strike. There is also the potential for a lot of discomfort and pain which in turn causes other compensations to occur. These may lead to the orthosis not being worn a great deal or not at all.

    Macro is about looking at the body as a whole as against micro which is looking at ankle and foot with an array of labels which been created to cover various joint alignments.

    Dynamic is focusing on time and change. It is about asisting a patient in developing their awareness of how their body moves.

    Hence a meeting of the minds working with how a patient moves.
  5. Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    OK, I'll bite. Please define "an incorrect heel strike" and in so doing please define "a correct heel-strike". In fact, new thread please Moderators.
  6. Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    First of all, Tensegrity, you have chosen a name that immediately annoys me given the past history of our discussions here on Podiatry Arena. It would probably help you, with many of us, if you provided us with your real name so we can somehow get past the "Tensegrity" label you gave yourself. I hope you don't go the way of "Sicknote" here on Podiatry Arena.

    Secondly, a foot orthosis can modify the position of the subtalar joint (STJ) at heel strike and thus modify the position of the foot/heel at heel strike during walking. I have observed this many times and first observed it 27 years ago during slow motion video analysis of a patient during my Biomechanics Fellowship. This ability of the foot orthosis to reposition the STJ at heel contact is likely due to the foot orthosis allowing the STJ to assume a less pronated position during propulsion so that, during swing phase, the anterior tibial muscle is now a supinator of the STJ rather than a pronator.

    By the way, Tensegrity, please explain how Buckminster Fuller's concept of "tensegrity" applies to the human locomtor apparatus.
  7. Griff

    Griff Moderator

    Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    So, it's what the rest of us refer to as taking a holistic approach to patients with musculoskeletal complaints. Not really any need for the fancy 're-branding' of what we all do on a daily basis, but each to their own I guess... Baffle 'em with BS and all that...

    I agree with Simon - the discussion that will inevitably ensue now regarding your nonsensical comments on heel strike are worthy of their own thread. Mike?
  8. Tensegrity

    Tensegrity Active Member

    Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    Rather than define an incorrect heel strike. Let's turn it on it's head and define a correct heel strike.
    This is a heel strike which is square to ground in the frontal plane and approxiamately a quarter of an inch in on the heel.
  9. Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    No, don't get it. "Square to the ground"? What does that mean and "approximately a quarter of an inch in on the heel"? What if the heel of my shoe is less than a 1/4 of an inch in width at it's contact point with the ground? What if we take two individuals with identical strike positions, but with different subtalar axial positions? Me thinks you're talking bollocks. But carry on.

    Since you spoke of an incorrect heel strike, I'd really like you to define it. But given your definition of a correct heel strike, I'll take it to mean anything that doesn't hit that strict criteria. So, your evidence for this "correct heel strike" consists of......?

    Like Kevin, these days I'm becoming more annoyed with the concept of anonymous posting. I should really like to know your name and background experience before I bother to contribute any more.
  10. Griff

    Griff Moderator

    Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    Kevin Bromley. http://www.stepintime.org.uk/
  11. RobinP

    RobinP Well-Known Member

    I thought most people were beyond correct and incorrect ......well....anything.

    Surely this is not worth discussion. Packaging inaccurate generalisations about biomechanical theory as somehow being more holistic. It's been done to death hasn't it?
  12. Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    One of my favorite Mary Poppins songs and dance sequences..."Step In Time"......:butcher::cool::eek:

    Last edited by a moderator: Sep 22, 2016
  13. G Flanagan

    G Flanagan Active Member

  14. Tensegrity

    Tensegrity Active Member

    Please let me know the easy way to change the name Tensegrity in the posting.
    I just happen to like the word because it is all about the balance between tension and compression. It is what i spend my days dealing with in order to resolve what ever the presenting condition is.There was no intension to be mysterous.
    As to heel strike , well the style of the foot wear is just one of many variables that have to be allowed for when working out how to create what is appropriate for an individual. The height and type of heel on footwear is just another factor.
    To me working out the differences is what it is all about. The goal is same for all - no pain and ideally no need to wear an orthotic.
    There is no better feeling than that of knowing a person walked in to my clinic in pain and on leaving I am told there is comfort when walking and sitting.
    It is quite priceless knowing I have been able to help someone have a better quality of life.

    Kevin Bromley
  15. Kevin:


    Just so long as I don't have to call you "Tensegrity" all the time, then we should be fine. I rather like your real first name.:rolleyes:

    There was another "Kevin" who was also a big fan of tensegrity from a few years ago here on Podiatry Arena. The other Kevin promised us all oodles of research that he was going to publish. Unfortunately, we haven't heard from the other "Tensegrity Kevin" (I forget his last name) in a few years or seen any of his promised research that he constantly reminded us of....maybe he got lost in a cybercloud?
  16. Tensegrity

    Tensegrity Active Member

  17. davidh

    davidh Podiatry Arena Veteran

    Re: Podiatry’s Future: Biomechanics Versus Surgery Or Biomechanics With Surgery?

    I feel pretty comfortable stating that there is no such thing as a correct heelstrike.

    There is certainly an optimum heelstrike, depending on the individual foot/leg geometry, physiological health, weight, and the type of supporting surface.
    But what may be optimum for an 80 year-old walking on pavements may not be optimum for a healthy 25 year-old walking on grass, or a 40 year-old who is very overweight and has uncompensated equinus (or pes cavus, if you prefer).
  18. No that's incorrect. A correct heel strike is inverted by 2.5 - 5.5 degrees.
    Last edited: Aug 26, 2011
  19. to what ?

    and what. ;)
  20. RobinP

    RobinP Well-Known Member

    I've been thinking about macro biomechanics. I think there is a better name for it.

    I personally like to call it "treating patients"
  21. No idea. But as long as we were making arbitrary statements about what is "correct" I'd join in and make my own guess.

    Check my edit Mike ;).

    The point being meant for Kevin. Simply to state what is "correct" is worthless unless one can justify ones answer. 2.5 degrees (the .5 was a clue that i was being facetious )is an absurd concept for "correct" heel strike, as is zero degrees.
  22. Wasn't there some kind of top secret evidence which he'd read but could not reveal for legal reasons? Which he said would make all of us look really stupid when it was released?

    Still waiting on that then.
  23. Here is the tensegrity thread from three years ago where Kevin Miller participated.

    Biotensegrity and Mechanical Analysis

    I wonder when all that top-secret tensegrity research will ever reach us lesser mortals?:rolleyes:
  24. I suspect it is. If you look at some of the other patents, one of them is basically a contact digitiser in which the force applied by individual pins can be controlled to apply specific forces to specific areas of the foot- could have sworn I talked about that idea on here.:morning: Didn't think you could patent things that were already in the public domain.
  25. David Wedemeyer

    David Wedemeyer Well-Known Member

    I'm not sure that Kevin Bromley is the same person as Kevin Miller. I had a brief email conversation with Kevin Miller and he indicated that he held an MS degree, was an ATC and a C.Ped. He also claimed he had completed all but two quarters of the chiropractic curriculum and that he planned to finish that degree. This was June of 2009.

    Here is the link to the website he referenced in his email:

  26. You misunderstand, David. We are not saying kevin Bromley is kevin Miller, we are saying the Kevin Miller associated with tensegrity technologies is the same Kevin Miller that used to be rubbish at answering questions here.
  27. David Wedemeyer

    David Wedemeyer Well-Known Member

    Simon thank you for the correction, I read Kevin's post incorrectly. Kevin Miller is apparently the same poster mentioned in the tensegrity threads that is also involved with Tensegrity Technologies LLC.
  28. Tensegrity

    Tensegrity Active Member

    I looked at the web site for Tensegrity Technologies LLC. There is just a brief description of it's purpose, the date it was founded and an e-mail address.

    I have also looked at Craig Payne's posting on bare foot running and the responses to it. Clearly there is a group of you who know each other well.

    I would like to know your views on something very basic which is :' the way our legs and feet are formed, our knees and feet should point in the direction we are moving.

    Kevin B
  29. Disagree.

    This implies there is only one position for the feet and knees. There's not, there's a range.

    IF the foot was pointed in the direction of travel, the knee will cease to point in the direction of travel as soon as the foot starts to pronate (because the leg will internally rotate).

    In fact, if you allow for movement at the sub talar joint (which you have to) then its impossible for the feet and the knees to be pointed in the same direction for more than an instant, The leg rotates on the foot, the foot seldom rotates on the ground once fully weight bearing.

    The question contains a catagory error. One cannot think of gait in terms of a single direction or position, its all ranges.

    The only way I can think to make the knees and feet point in the direction of travel throughout the gait cycle would be to fuse the sub talar joint (to prevent rotation of the leg on the foot), fuse the hip so it only works in the saggital plane, ensure the foot was aligned with the knee, prevent the pelvis from moving in the transverse plane (to ensure the body did not pivot on the supporting leg) and somehow force the feet to always land facing forward.

    Is this your justification for the heel striking square being "correct" by the way?
  30. Tensegrity

    Tensegrity Active Member


    Thank you for response.

    I agree there are huge variations in joint alignment and it is working out what is going on that I find so stimulating. To me it is like being a dectective and it is piecing it all together that is the challenge.

    In some ways it seems to boil down to timing as our body's manage change.

    In a sense, much of what we do revolves around habits and habits are the product of what we have done before. I believe alot of the conditions we treat are result of the body compensating for a wide variety misalignments and imbalances arising from what we do with our body.

    So there has to be a point during the gait cycle when the knee and the foot points in the direction the body is moving in and when that does not happen eventually a problem arises. Pain progressively getting worse if the underlying issue is not addressed.

    Thank you again for taking the time to reply.

  31. Actually that is pure hypothesis on your part. From a mechanical point of view, you could argue that it is less important to have the bony segments in-line with the plane of progression (you're never going to get all of the segments in-line with the plane of progression) than to have the active rotational axes normal to the progression plane (you're never going to achieve that either, but since we're talking hypothetically). We call that: "a wheel"
  32. Tensegrity

    Tensegrity Active Member

    I am not quite sure how to respond to your comment.

    The reason I put that point forward was because that has to being happening otherwise none of us would ever get to where we are going.

    A good example of when this is not the case, is when a traffic policeman stops a driver who has drunk too much alcohol and is therefore unable to walk a straight line when unfortunately asked to do so.

    I believe a lot hinges on our knowledge of ourselves.

  33. And I believe, as I've previously stated, that you are talking bollocks. The individual segments don't have to point where we are going, merely the centre of mass has to be transported there as efficiently as possible. Tell me how when "our knees and feet point in the direction we are moving", this adds to the efficiency of gait.

    The thing about people like you Kevin, who appear to make it up as they go along, is that often they make it up as they go along and under the slightest scientific scrutiny their arguments and hypotheses crumble. It's one thing convincing the lay public, lets see if you can convince me or any of our peers. So, defend you contention...

    No alarms and no surprises. http://www.youtube.com/watch?v=2Lnltl3YoqQ

    In the meantime, here is something better to read, Arthur Kuo talking about walking models: http://www-personal.umich.edu/~artkuo/Papers/HMS07.pdf

    Here's the rest of his work: http://www-personal.umich.edu/~artkuo/Papers/
  34. Griff

    Griff Moderator

    You don't think this has more to do with the transient neurological effects of being intoxicated rather than the fact the knee and foot are not aligned with each other Kevin? Poor analogy. Works with your patents I'm sure.

    I saw a chap with a significant external tibial torsion bilaterally today. Ain't no way any of us could ever make his knees and feet face in the same direction. And I'd wager they dont even come close to this position at any stage of his gait. I'm making the bold assumption that as he got from his home to his place of work this morning, and then from his place of work onto the tube and across to see me for his appointment that he 'got to where he was going'. Would you disagree?
  35. efuller

    efuller MVP

    Why? It is entirely concievable that someone could not have their knees and feet in the line of progression and be completely symptom free. Even if they do come into the office because of pain, the joint allignment may be entirely unrelated to the cause of the pain. I'd have to agree with the others that have pointed out that the vast majority of individuals don't have the long axis of their feet alligned with straight ahead travel. What happens if they want to make a right turn?

  36. Well everyone else has already said pretty much what I would have said about this, with varied degrees of bluntness. Even if we leave the knees alone for a minute, most people walk with their feet somewhat abducted, not in the direction they are traveling. Yet they get where they are going. Our old friend Haile Gerbralassie

    is the best distance runner in the world, and he runs with his feet quite substantially abducted.

    So clearly most of us do NOT walk with our feet pointing the direction we are traveling.

    And even if we were, as I stated before the only way to line the knees up to the foot would be to prevent the leg internally rotating, viz, to prevent the foot pronating.

    But lets say we accept what you say, assuming you're accepting that we can't prevent pronation and that if the foot pronates the knee and foot rotate relative to each other, at what point during gait would you suggest that they SHOULD come into line in the saggital plane?
    Last edited by a moderator: Sep 22, 2016
  37. Orthican

    Orthican Active Member

    May I chime in regarding what is "proper heel strike"?...First off I fully agree that we can assume a "range" where this is concerned and pigeonholing this position to within a few degrees or parts of an inch or millimeter will only confuse you more. Step back and look at the big picture. People come in all shapes and sizes and most of the ones I deal with would NOT be considered your "textbook" "normals" and moreover what is "normal"? ...for me it is a range again.

    But for me an optimum heelstrike achieved by that person I am looking at will be one that allows for continuation of weight acceptance on that foot with stability. Again for each person this will be slightly different depending on the position of that load over the subtalar. Measuring that position in all thee planes is nice and makes for a more well rounded informational exchange within my chart but really does not matter much to the person who is walking because there is a wide range of postions both retroverted and anteverted in hip transverse plane position, tibial angle, subtalar position and foot morphology that would give "optimum heelstrike".

    It is not wise in my opinion to attempt to get all people into one measured position to satisfy a parameter.

    My 2cents

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