“WRING THEORY” old biomechanics with a new twist
Members do not see these Ads. Sign Up.
A novel interpretation of form and function that incorporates anatomical study with bioengineering principles. Is this the "missing link" that might unify biomechanical paradigms?
Grab a pot of coffee... and enjoy!
Page 1 of 3
-
-
Interesting ideas ... its going to take a while to digest this one!
-
After a very quick look.
The Wring idea i've seen before. I believe Sarafian copied it from someone earlier. Oh no not tensegrity. You can analyze tensegrity structures with classical mechanical principles. The foot is not a tensegrity structure.
The author did put a lot of work into it. -
A quick look suggests to me that there is nothing new here - I will retract if required after a proper read. Rob
-
Is a theory of foot function required?
-
If you don't like the STJ axis example, think about reasons for giving someone a forefoot valgus intrinsic post.
Eric -
-
-
I had been told about this "theory" of foot function a while ago. To me, it seems like a rehash of Sarrafian's twisted plate idea which Simon mentioned. What specifically new does this "wring theory" tell us that was not already present in Sarrafian's twisted plate idea?
In addition, I agree with Eric that "tensegrity" has no place in discussing foot function since tensegrity specifically addresses systems with no compression forces at the intersections of two elements of the system. Since when do the foot joints not have compresion forces acting within them?
I don't think this "paper" could ever be accepted for publication in a peer-reviewed journal as it is. However, a vastly shortened form of this "paper" may be acceptable for publication, if it could be shown to present truly original ideas.
-
-
By the way, Sarrafian's twisted plate idea came from MacConail and Basmajian's idea of the "lamina pedis" (MacConail MS, Basmajian JV: Muscles and Movements: A Basis for Human Kinesiology, p. 246, Baltimore, Williams and Wilkins, 1969).
http://books.google.com/books?id=I8... Basis for Human Kinesiology, p. 246,&f=false -
Anyway, to answer the original question: "Wring Theory" of foot function - The Missing Link? No. Next... -
-
More bad mechanics. Has a picture of a truss and notes how truss has tension in one member under load. Figures 10 and 11a-c draws triangles but there is no analysis of load. The transverse and coronal trusses don't have tension members.
-
I will send Clint an e-mail to see if he wants to discuss his "Wring Theory" on Podiatry Arena. -
-
-
-
-
Just spoke with Clint on the phone and he promised to come onto Podiatry Arena and defend his theory for us.
OK, Clint...the floor is yours... -
Thank you for the invite. You will have to be patient with me. This is the first time I have posted and am still figuring this forum out. Dr. Kirby mentioned hearing of this before. There was a watered down version published in Podiatry Management, September 2011. This may have been where you saw it. As for discussion of the theory, I will request that those who want to post regarding this theory first take the time to read completely through my article a couple of times before joining into the discussion. Please be sure to review each of the videos and figures. Figure one is a gross representation of the resulting biomechanical model of the whole paper. The paper then proceeds to break down each component contributing to this resultant model and how nature has achieved this complex function. I want to clarify that this article has been 4 years in the making and I have had to step back repeatedly to make sure this theory represented the current/past schools of thought and then fill in where I believe the holes are. In addition, the article is to simplify foot biomechanics by breaking it apart and remeshing it in a stepwise fashion. This serves to allow the student to understand the foot from its rudimentary components to its final symphony of function. In this way, I hope to overcome many of the hurdles I encountered in learning it myself. I present it now as I need to make sure I have not overlooked any details, which in this case, are very complex. Does some of it sound familiar? Of course it should. It incorporates many of the past thoughts and articles upon which current theories are based. Thus the title, "old biomechanics with a new twist." I will need a little time to answer some of your current posts, so please be patient. I am excited to talk with the likes of you.
Clint -
1. How do you think your "wring theory" is different that Sarrafian's twisted plate model, since, to me, it looks nearly identical to it?
2. How can tensegrity be used to understand foot function when tensegrity specifically doesn't produce compression or moments at the joints of the tensegrity elements and any bending moments of the tensegrity elements? The human foot does have compression forces existing at its joints, does have moments existing at its joints and does have bending moments acting across some of its osseous components. Therefore, the foot cannot be a tensegrity structure. -
See this section from the book too: http://books.google.co.uk/books?id=...=0CCEQ6AEwAA#v=onepage&q=lamina pedis&f=false
I'll await Clint's answers to Kevin's questions above, before posing any of my own. Tick tock...
http://www.youtube.com/watch?v=oMQl8UvtOgQ&feature=related -
-
-
"What has been will be again,
what has been done will be done again;
there is nothing new under the sun." -
-
This is not someone that I would recommend consulting before writing a paper on foot biomechanics.:bang::bash: -
http://www.youtube.com/watch?v=MUt7qmSvxLI
Anyway, if the soft-tissues which Sarrafian described decrease in tensile strain when the hind foot is supinated, but the dorsiflexion/ plantarflexion stiffness of the midfoot is increased due to the increase in 2nd moment of area with the foot in this position, then the increase in 2nd moment of area appears to be a compensatory mechanism to maintain dorsi/ plantarflexion stiffness of the foot when certain soft tissue tension is reduced. Or, vice versa. The reverse of this would also seem true, i.e. the reduction in the 2nd moment of area which should result in decrease in midfoot dorsi/ plantarflexion stiffness which occurs with hind foot pronation should be negated by the increase in the soft tissue tension which Sarrafian described. Which begs the question- is the foot really stiffer in one rearfoot position or another, or does it pretty much stay constant? Viz. is the mobile adapter to rigid lever hypothesis even valid?
Something tells me the spirals within the double helix model Clint built should have opposite directions (one clockwise, the other anti-clockwise) such that within mid-range of the foot the double helix is unwound, but as we approach the end of range in either direction: supination or pronation, they should tighten- isn't this what we see- a close packing of certain structures with maximal pronation and close-packing of other structures with maximally supination? Just a thought since Clint appears to have vanished up his own wring theory. -
I think you are scaring him....he's seen your photo with Yoda....;) -
-
-
Looks like Clint has gone missing here. I wouldn't think it would take much time to answer a few questions regarding someone's "theory".
In that regard, didn't Ed Glaser also go missing for long stretches when we were trying to ask him questions here on Podiatry Arena about his MASS "Theory"? Is there a connection betwen Ed and Clint??? Looks like Ed's son, Noah, helped Clint with his Wring "Theory" (see end of paper).
Regarding Ed Glaser, he now has another propaganda video on YouTube that is rather comical....lots of great quotes out of this one.....:butcher::bang::eek:
Last edited by a moderator: Sep 22, 2016 -
I have written and lectured quite a bit about the load-deformation characteristics of the medial and lateral longitudinal arches of the foot and have long tried to emphasize the spring-like characteristics of the medial and lateral longitudinal arches, including the midtarsal and midfoot joints. At the California College of Podiatric Medicine (CCPM) we were taught about the "locking mechanism" of the midtarsal joint, while the concept of load vs deformation was never mentioned.
"Midtarsal joint locking" was taught in the sense that that both the "oblique" and "longitudinal" midtarsal joint axes had a "locked position" when the examiner dorsiflexed the lateral forefoot against the resistance of the Achilles tendon. It was not emphasized at CCPM that the foot (and midtarsal joint) will certainly flatten more at the medial and lateral longitudinal arches with increasing loading forces. In fact, during my time there as a student and Biomechanics Fellow from 1979-1985, to my recollection, no one questioned the belief that the midtarsal joint "locked" and no one suggested that the foot acted as a spring type mechanism.
I had read about Sarrafian's "twisted plate" idea many years ago and had seen MacConail's idea about the "lamina pedis" during my Biomechanics Fellowship in 1984-1985. I thought this was an interesting idea but rather a much too simplified model of the human foot to be of much value. However, the "twisted plate" and "lamina pedis" did have the advantage of recognizing the spring-like characteristics of the human foot, thereby discarding the idea of "midtarsal joint locking". Root and coworkers never mentioned the "lamina pedis" or "twisted plate" ideas at any time that I remember, and certainly didn't recognize these ideas in their books.
For me, in skimming over the Wring "Theory", it seems to be basically a reintrooduction of the 43 year old idea from MacConail of the "lamina pedis" which was later modified by Sarrafian 25 years ago into a "twisted plate" idea. Maybe Clint will come onto Podiatry Arena and enlighten me as to how I am wrong. However, for now, it seems we have yet another author taking some older ideas, reintroducing us to them, and giving these old ideas a new name.
The renaming of these rather old ideas into a new "theory" of foot function, reminds me somewhat of Ed Glaser claiming he was the first to make a high-arched orthosis, somehow forgetting to mention the fact that high-arched foot orthoses were invented over a century ago by Whitman and Shaffer. This is why it is so important to know the history of biomechanics and foot orthosis therapy.... so that the clinician can be savvy enough to know when something truly new and original is introduced into our profession. -
NOTHING HAS EVER BEEN NEW, JUST OUR WILLINGNESS TO DISCOVER IT.
My Theory is my own and I have meary run it passed others, as I have with you, to see where there may be potential issues.
As for the foot having a tensegrity component or not is to be seen. I introduce it, because it best describes the interplay of the suspension/tension seen in the structure of the foot. Yes, Dr. MacClanahan did introduce it to me, (awesome guy by the way) but “after” I had written the paper. I love how he has stepped beyond the traditional views. Good thing Columbus, Edison, and Einstein did. They were deemed fools of their time. The point of my paper was to look at all the thoughts out there and attempt to understand what gave birth to them. I have then tried to see how they interplayed with my concept, and if they did not, I have introduced something to replace them. Tensegrity is a much more involved science than we like to give it credit. It is still yet evolving, as to it application. The science has several authors and each tend to focus and give credit to their own particular segment of it. Tensegrity at its roots is Tensional Integrity. It is defined by the interaction of tensile and compressional components.
Synergetics 700.011:* “The word tensegrity is an invention: it is a contraction of tensional integrity. Tensegrity describes a structural relationship principle in which structural shape is guaranteed by the finitely closed, comprehensively continuous, tensional behaviors of the system and not by the discontinuous and exclusively local compressional member behaviors.”3
Fuller, R. Buckminster, 1975, Synergetics, Macmillan, pp 372
(Dr. Ingber has shown that this science plays an integral part in the function of the biological cell. He has shown that mere pressure on a cell membrane can alter cellular physiology as well as cellular membrane permeability, etc. If the body uses it at its most basic cellular structure, why would it reinvent the wheel for the macro scale of the body. Interestingly, at least in the cellular world, it has a preference in for Dr. Ingber has become well known in the application of tensegrity to biological structures, begetting the term, “biotensegrity.” He has shown how this compression/tension interaction can alter biochemistry and allow cellular membranes to change their permeability. This cellular, architectural property can be induced just by adding pressure or tension to a cell membrane. A very simple approach by nature to achieve a very complex, functional cell. His work has shown the biological shapes of nature have a preference for “spirals, pentagons, and triangulated forms.”)
When everything is balanced, there is no motion. When out of balance one sees a rotation. (Rotational Equilibrium Across the Subtalar Joint) This does not eliminate potential torque, the play between the lengthen of an object and gravity. It is just a matter of whether or not everything is in equilibrium.
Tensegrity, as used in my paper, is about how the foot uses rigid (compressive), and soft structures (tensile) to hold itself together. Grabbing a toe can create and effect into the rearfoot, and visa versa. (A dominant characteristic, of the coronal windlass mechanism, is the combined interaction of the posterior tibial and peroneal longus tendon and the dorsal ligaments. The coronal windlass mechanism is able to induce a rigid or flaccid construct, by the simultaneous contracture or relaxation of the posterior tibial and peroneal longus tendons. This wraps / unwraps the midfoot region, like the lashing of a bundle of sticks. With the relaxation of the peroneal longus and slip of the posterior tibial tendon, the individual bones of the coronal windlass mechanism are able to shift freely within the confines of their own contiguous joint capsules / ligaments. As the dynamic side of the windlass mechanism is shortened, the external ligaments or 'extrados,' are brought under tension and the resultant tensegrity effect induces an internal compression between the osseous components of the coronal windlass mechanism. Compression induced by tension. This action creates a suspended, rigid coronal arch of the midfoot articulations.
This coronal arch is a plantar based truss and beam with the windlass mechanism represented by the peroneal longus, inserting into the plantar portion of the medial cuneiform and first metatarsal and then coursing obliquely lateral.(Fig. 20-a,b) It pulleys through the cuboidal, peroneal groove and finally, courses proximal. This windlass pulley, (the cuboid), is stabilized by the medial draw of the posterior tibial tendon and the navicular tether. The engagement of this mechanism results in a helical moment of the forefoot. This induces distal, medial, coronal plane, eversion against a proximal, lateral, coronal plane, inversion, along with progressive, rigidity of this midfoot complex. The loss, or attenuation of the stabilizing effects of the posterior tibial tendon and navicular, on the cuboid, (ie; Subtalar joint pronation, Posterior tibial tendon rupture, Surgical advancement of the posterior tibial tendon without reefing the spring ligament and cuboidal slip, etc.), results in the instability of the cuboid at the midtarsal joint, and disabling the coronal windlass effect of the peroneal longus against an unstable Cuboid. This is due to a loss of tensioning of the dorsal and inter-cuneiform ligaments to 'screw home' this midfoot arch. Essentially, it would be like drawing a bucket up from a well, on a pulley, not fasten to the top of the well. The pulley would, whimsically, roll away with the rope each time one tried to reel in the bucket. As a result, the coronal truss fails to lock, and loss of medial arch height occurs, because the first metatarsal base cannot 'screw home' and stabilize itself into a stable, coronal truss. )
This is why I explain that the foot is more than a keystone arch, inspite of its many features there of. It remain intact and functional regardless of position, open/closed pack, open/closed kinetic chain. -
Clint aka DrWring
I like your analogy, description and analysis of foot function even tho I think it needs some refining it is a useful model. I don't think it is new, it is one, or similar to one, which I have used for many years and recently described in another thread. It uses parts of older models and previously described mechanisms but you have gone some way to formalising this model and introduced it as a distinct and independent concept that can be used apart from but also in conjunction with other models and concepts. I particularly like the analogy of the well bucket pulley, which gives a much better intuitive understanding of the midfoot coronal plane mechanism than locking or screwing up analogies commonly used in the past.
One thing you wrote -
Regards Dave Smith -
Thank you Dave,
Clint is what my friends call me.
I appreciate your objective kindness. It is obvious you have taken the time to objectively read the whole paper as many of the questions already asked, are answered in the paper. Please share the link to drwring.wordpress.com around. -
However, equally important is the concept that the exact same external forces applied to a foot (i.e. ground reaction force), acting in the exact same anatomical location, with the exact same magnitude, direction and three-dimensional location may cause vastly different internal forces within different feet, depending on their three-dimensional morphologies.
This is one reason why I believe that the lamina pedis, twisted plate and wring models all seem to be lacking. Neither of these models accounts for how different foot geometries drastically affects the internal loading forces within the joints of the foot in response to the same external forces.
An effective foot model must allow us to not only understand how the foot deforms under load, but also must allow us to understand the mechanical effects of three-dimensional morphology on the internal forces within the foot under load. The wring model does reintroduce some old concepts for us to consider, and, certainly, that isn't so bad. -
Thank you. In those regards, I share the same frustrations. Roots original religion was that if one could properly analyze a given foot, one could consistently predict and reproduce a given result by the external forces applied. This obviously proved to be more difficult than originally planned. Even something as restrictive as a UCBL could not consistently yield a consistent result. Combine this with the result of application of a given device, or even surgery on an adult and then the same thing on the child of said adult, the results can be totally different. This why I have always been dissatisfied with the original foot model I was taught.
There was a comment as to why I included an anatomy book at the end of my article along with a glossary. If you read it and compare it to anatomy books you will find that several cases it does not follow the typical descriptions of the joints, and muscles. I am a sculpturer at heart, and that is how Dr. Phillips and I first met. I am very visual. He was my professor and in an attempt to understand the things he was teaching I needed a 3-D representation of the foot, especially of the STJ, as that seemed to be at the heart of all the discussions. The end result was a 24" long calcaneus and proportional talus that I drilled a hole, parallel to each cardinal plane, so I could place a dowel in and see an exaggerated motion in each plane. It turned out to be an effective teaching tool. All the pictures, dissection, and video you see in the paper are my personal work. I wrote a description of each joint and how it was contoured. Very interestingly, with few exceptions, they have a helical twist like a propeller. This is a helix. Look at the description of the 1st, 2nd cuneiform joint. No this does not answer how to predict and control its interface with external forces, but it is a solid basis from which to start.
Kids need me, will try to continue tomorrow. Thanks
Clint -
Page 1 of 3
Loading...
- Similar Threads - Wring Theory foot
-
- Replies:
- 0
- Views:
- 774
-
- Replies:
- 4
- Views:
- 10,118
-
- Replies:
- 1
- Views:
- 11,575
-
- Replies:
- 99
- Views:
- 36,979
-
- Replies:
- 6
- Views:
- 8,184
-
- Replies:
- 936
- Views:
- 194,197
-
- Replies:
- 1
- Views:
- 6,220