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How Far Have We Come in Podiatric Biomechanics?

Discussion in 'Biomechanics, Sports and Foot orthoses' started by Kevin Kirby, Mar 20, 2008.


  1. Members do not see these Ads. Sign Up.
    Even though I would sometimes like it to not be true, I am becoming somewhat of a "senior statesman" within my profession since I have been teaching podiatric biomechanics for over 23 years now. As such, I have seen and have been taught by many of the legends of podiatric biomechanics (e.g. Drs. Root, Weed, Sgarlato, Orien, Valmassy, Blake) who had many different ideas than what we teach now.

    For those of you who haven't been around this profession as long as I have, I thought it might be helpful for you to become aware of some of the biomechanics concepts that I was taught as a podiatry student from 1979-1983 at the California College of Podiatric Medicine so that you can see how far we have come in the past quarter century in our knowledge of podiatric biomechanics. Some of you other more mature podiatrists, that have also been around the profession for a decade or more, and may have been trained in other podiatry schools in other countries, may also want to contribute to this thread for the benefit of our younger colleagues.

    Old Concepts in Podiatric Biomechanics
    (circa 1979-1983, California College of Podiatric Medicine, San Francisco, California, USA)

    1. Measuring foot deformities such as forefoot to rearfoot relationship, rearfoot varus/valgus allows the podiatrist to best determine how a foot will compensate for those deformities and how best to make an orthosis to prevent those compensations from occurring.

    2. A foot is not normal unless it has a perpendicular forefoot to rearfoot relationship, stands with the subtalar joint (STJ) neutral, has a vertical distal third of the tibia, and stands with the calcaneus vertical.

    3. The heel bisection and forefoot to rearfoot relationship is easily determined and does not vary considerably from one examiner to another, if performed correctly.

    4. The midtarsal joint consists of two distinct simultaneously occurring joints, the oblique midtarsal joint, angulated 57 degrees from the sagittal plane and 52 degrees from the transverse plane and the longitudinal midtarsal joint, angulated 9 degrees from the sagittal plane and 15 degrees from the transverse plane.

    5. A functional foot orthosis should always be balanced with the heel vertical since heel verticality is the position that a normal foot has. The only time that a foot orthosis should be balanced with the heel inverted are in cases where the calcaneus is inverted when it is maximally pronated.

    6. A functional foot orthosis should never be balanced with the heel everted unless the foot is fixed in a heel everted position such as in peroneal spastic flatfoot or STJ degenerative joint disease.

    7. A true functional foot orthosis ends at the metatarsal necks. Forefoot extensions are not necessary to make the foot function optimally with a foot orthosis since placing padding plantar to the metatarsal heads will restrict digital dorsiflexion during propulsion.

    8. Pronation occurs frequently in feet since, during standing and walking, the center of mass of the body is positioned medial to each foot which forces feet to pronate.

    9. Gravity causes pronation.

    10. A foot with a vertical calcaneus in standing and with the STJ in neutral position is the most stable foot.

    11. The goal of foot orthosis therapy is to make the foot function in the STJ neutral position.

    12. Foot orthoses need to be made of a relatively rigid material in order to be considered true "functional foot orthoses". Soft materials can not be used to make functional foot orthoses, soft materials can only make "accommodative orthoses".

    13. A calcaneus that is resting 2 or more degrees everted will continue to pronate to the maximally pronated STJ position during relaxed bipedal stance.

    14. A foot with a rearfoot varus deformity will pronate until the heel becomes vertical unless it is supinated by some other influence since the heel vertical position is the most stable position of the foot.

    Any other "mature podiatrists" wish to contribute?
  2. markjohconley

    markjohconley Well-Known Member

    Gives me a warm fuzzy feeling, thanks Kevin. Hopefully others, whose brains haven't gone to putty, will contribute. Mark C
  3. Mark:

    I thought that others that were trained over a decade or more ago could either confirm or deny that they were taught these ideas. Or perhaps they were taught other ideas that I did not list and could add those. This is extremely helpful for the younger podiatrists who, often, only learn the present theories, and don't know where we have come from.

    Craig Payne, Simon Spooner, Eric Fuller, David Holland, Cameron Kippen and others........are you out there?
  4. efuller

    efuller MVP

    Yes, Kevin, I was told all of those items. Reading Eric Lee's history of Root biomechanics (clinics in podiatry in the last 6 years) is very interesting where he gives cites for many of those points. Eric Lee went extensively into the concept that there were two definitions of normal that are not compatable all of the time. In addition to the biophysical criteria of normalcy there is the the much more practical normal (I'm paraphrasing) is the ability to carry out every day functions without pain in the foot.

    There are many inconsistancies in what was taught by Root, Orien and Weed. To name a couple, a forefoot valgus causes pronation of the STJ and it causes supination of the STJ. The logic used to explain both is tortured. An equinous causes supination and pronation of the STJ. Again tortured logic in one of those explanations. This phenomenon can be easily explained using position of the STJ axis.

    I could go on, but I'm greatful to Kevin for writing his palpation of the location of the STJ axis paper while I was still young enough to question what I was taught.

    With all those inconsistancies it was no wonder that students would graduate with good grades in biomechanics and still feel that they did not understand it.

    Cheers, Eric
    Last edited: Mar 21, 2008
  5. Shane Toohey

    Shane Toohey Active Member

    Thanks Kevin, Eric

    I think this a very useful discussion because many of the concepts mentioned are now part of the amorphous mass of concepts that swirl around in the deeper recesses of many of our understandings of biomechanics. I also suspect that many pods rely more now on following a set practical routine for arriving at the practical solution rather than trying to think too deeply about how it all works.

    Eric wrote:

    I remember not really believing that almost everyone really had a "flexible" forefoot valgus and you only had to put the foot into a certain position to find it.
    This caused STJ pronation. Most of the remainder had a 'rigid' forefoot valgus which caused STJ supination.

  6. Cameron

    Cameron Well-Known Member


    Root et al podiatric biomechanics impacted in the UK after Sheldon Langer and Dr Warnick held seminars for pod teachers in London. Some UK pods had been aware of Roots observations and publications, but it was only after the establishment of prescription foot orthotic services aka Langer, that greater dissemination in the pod community took place. I taught foot orthotics and prosthetics in the ungraduate program and also was involved in CPD. Like all my contemporaries the Root theories and nomenclature were adopted carte blanche from 1981 onwards into the UK podiatric undergraduate programs. A quick review of the examination papers in the SOCP archives will confirm this change. In the UK there was a national set of final papers and so every final year student sat the same paper on the same day.

    In 1979/80 I was clinician/manager looking to make sense of orthotdigital therapy and when I discovered the sub talar casting technique I was in seventh heaven because the manipulation gave an ideal reference positon for serial orthotic comparisons.

    After teaching Californian biomechanic theory for four years or so in 1985 I spent sometime at Strathclyde Univeristy, Bioengineering Uint with Dr Sandy Nichole reading for a post graduate diploma in biomechanics. T'was the schooling in bioengineering that eventually meant I could no longer accept the rudimentary principles of podiatric biomechanics as a true explanation for foot function. This did not seem to be too out of place with the writings of the primary author (Root) who hoped that better understanding would follow and there was a promise of a third edition which never came.

    From that time I always used Inman Ralston and Todd's approach as a basis for gait analysis and to teach pod students about three dimensional movement. By way of introduction to prescription orthotics I would use the STJ theory mainly as a descriptive model for foot function and pathology.

    Never truely satisfied with the limitations of the orignal theory I was very interested to meet Craig Payne in the early 90s and read of his sagittal plane model a little later. I do find contempory descritions have far more substance, albeit as you know, I have always been in awe at the brilliance of Root et al's thinking, all those years ago. I also admit to beeing 'a voice in the wilderness' as I would remove the Root Theoroies from mainstream curriculum as they are now outdated.

    In my time I have met many gifted foot orthotic prescribers and technicians and they never fail to amaze me about how they problem solve with their clients, but I have also ran across a lot more 'bull ****ters', and others who do not appear to have much of a clue about what they do, other than follow a party line.

    I have always preferred to classify foot orthoses by material (simply because I have a material science background) and clinically gage their initial fitting through comfort - rather like a good fitting shoe. I use over the counter devices for preference.

    So maybe not the best person to be asked to be nostalgic.

    Anyway, have a good Easter.

  7. Here are a few more of the "facts" I was taught as a podiatry student at CCPM.
    15. Since the foot is casted for functional foot orthoses in STJ neutral position and since the foot orthosis is made around a positive cast in STJ neutral position, the foot will function in the STJ neutral position when wearing a functional foot orthosis.

    16. Functional foot orthoses work by preventing compensations for forefoot to rearfoot deformities.

    17. Functional foot orthoses work by "locking the midtarsal joint".

    18. Inverting an orthosis will cause the patient to get bunion deformities since an inverted orthosis will supinate the longitudinal midtarsal joint axis.

    19. The plantar fascia cannot add a STJ supination force to the foot since the plantar fascia is not a muscle.

    20. Equinus deformities will cause a pronated, flattened longitudinal arch of the foot sometimes and will cause a supinated high-arched foot other times. (Thanks for that one, Eric.)
  8. Scorpio622

    Scorpio622 Active Member

    21. The shorter leg supinates and the longer leg pronates.

    22. The forefoot controls the rearfoot.

    23. Foot deformity can be classified based on hyperkeratotic lesion patterns.

    24. Podiatric Biomechanics is primarily a kinematic analysis- owing little to kinetic and neuromuscular influences
  9. CraigT

    CraigT Well-Known Member

    Last edited by a moderator: Mar 23, 2008
  10. davidh

    davidh Podiatry Arena Veteran

    My podiatric biomech history is pretty much as Toeslayer laid out, and especially the bit about bioegineering education showing up the cracks in pod biomech thinking.

    Nowadays I tend to use simple theory backed up by orthoses from a good, reliable lab - works for me;).

  11. Craig:

    I was rather hoping that others (as a few have already) would be able to contribute to my list of specific ideas that they were taught years ago during their podiatric education. The purpose of this is not to repeat the "fallacies of podiatric biomechanics" thread, but rather to develop a list of outdated ideas that demonstrate to the younger podiatrists following along how our "dogma" in podiatric biomechanics can change quite dramatically over a relatively short time span.
  12. CraigT

    CraigT Well-Known Member

    Understood Kevin- the point was not that the thread was being repeated, more that the outdated ideas that were being taught, we now regards as fallacies.
    I have truble adding to the list... you have already covered most of the ones I could think of!

    Interestingly, I remember Karl Landorf studying the prescribing habits of Australian Pods and finding that you could tell where and when Pods were educated by the types of devices they prescribed. I feel fortunate that in the early 90s when I studied, we were introduced to Blake inverted orthoses and Kirby Skives at an undergrad level... I believe many from my era from other universities never had this exposure (I could be wrong though).
    What has changed significantly is that with the advent of the internet and email(and Pod Arena!)- keeping 'up to date' is so much easier!
  13. Craig:

    An event during my early biomechanics education is still vivid in my mind regarding how ideas change over time.

    During my Biomechanics Fellowship, in 1984-1985, I functioned as one of the clinicians for the podiatry students I was teaching (Eric Fuller, David Armstrong, and Larry Huppin, are a few of the famous ones I had the pleasure to share knowledge with). When I started my fellowship, Dr. Jack Morris came back to CCPM to be a biomechanics faculty after having been in private practice for 15 years. Therefore, Dr. Morris and I spent a lot of time discussing biomechanics concepts together in the clinic. At the same time, Dr. John Weed was still coming into CCPM once a week to teach the second and third year students, and I continually peppered Dr. Weed with numerous questions regarding concepts on foot function after he was done with his lectures.

    One day, Dr. Morris and I were examining a patient during my Fellowship and he showed me how, in some patients, if the patient was asked to stand on an "orthoposer" (a small platform for examining patients while standing), and was positioned so that their digits were hanging off the edge of the orthoposer, but the metatarsal heads were still supported by the orthoposer, that the hallux would rest in a plantarflexed position relative to normal. We both noticed also, in the patient we were examining, that the calcaneus would evert when the hallux plantarflexed below the plane of the supporting surface of the orthoposer and the calcaneus would invert when the hallux was dorsiflexed to the level of the supporting surface of the orthoposer.

    After discussing this with Dr. Morris, we concluded that the plantar fascia actually was placing a supination force on the subtalar joint (STJ) due to its ability to invert the calcaneus when the hallux was dorsiflexed to the level of the plantar foot. I remember quite clearly that this was quite a revelation for me at the time since I had never been taught that ligaments could supinate the STJ, only muscles could perform that function.

    The next time I spoke with Dr. Weed, I told him of our observation and told him that the plantar fascia, as a ligament, must be able to place a supination force on the STJ since raising the hallux to "ground level" had inverted the calcaneus very clearly. He told me that this could not be the case since everyone knew that ligaments could not actively supinate the STJ. After probably 5-10 minutes of rather lively discussion, I could not convince Dr. Weed of the concept that seemed so clear to me, that not only muscles have the capacity to exert a supination force on the STJ but that supporting ligaments must also have that capacity.

    Up until that time, I had considered Dr. Weed to be "deity-like", perfect in his knowledge, since he knew so much more than I did and his ideas always seemed to make sense to me. This one incident was profound for me in that the man that I most respected in his knowledge of podiatric biomechanics I now found to be imperfect. This event then led me to start questioning and examining all the other things that had been taught to me by him and my other biomechanics professors.

    Now, 23 years later, I realize that this event, was an important part of my education and development as a researcher and educator in foot and lower extremity biomechanics. I began to realize that just because someone I respected greatly said it to be so, didn't mean it was so. I knew I had to analyze my own observations along with my understanding of Newtonian physics to see if what I had been taught still made sense.

    These types of lessons are very important for our younger generation of podiatrists so that this profession may remain strong in their knowledge in this most important of fields: podiatric biomechanics. Teaching these lessons is exactly what I am trying to accomplish with this thread.
    Last edited: Mar 23, 2008
  14. Scorpio622

    Scorpio622 Active Member

    I see these as the same thing.

    What would be interesting is to compare ideas that were totally false (fallacy thread), to those that were not accurate but were along the right path and served as a foundation for more sound ideas.
  15. Stanley

    Stanley Well-Known Member


    As a podiatrist who has been around a longer than you have, I feel that I should contribute to this thread.

    I visited CCPM in 1976, and spent a week there to see what was being taught. I agree with what you are saying. The thing that was taught there that I remember the most was in casting class. Dr. Smith taught that you can see the first metatarsal pushing downward in a correct (or was it incorrect) cast. I couldn't see it or understand how you could see it.

    California was not the only place that biomechanics was being taught, and not everyone followed the California model exactly. In Ohio for instance, Root theory was taught in the classrooms, but in the clinic Morton's foot was epidemic. A latex felt device with a vinyl top cover and Morton's extension was prescribed. Funny as it may seem, the runners really liked them.

    In New York, there was Wernick and Schuster. Wernick taught root theory, as did Dave Skliar who worked closely with Schuster. Skliar and Schuster had a different application of Root's theory.
    We were taught:
    1. A leather device is flexible, but not compressible, so it could be a functional orthotic.
    2. The best way to support the foot was by placing material under the forefoot, since the foot was akin to a three legged stool.
    3. The long leg pronates.
    4. When in doubt add a heel lift.

    Schuster had a three month waiting list to be seen back then, and was in People magazine, and was the podiatric consultant for Runner magazine (before they merged with Runner's world).
  16. Stanley

    Stanley Well-Known Member

    One more thing, we were taught that muscles had no effect, rather it was ligaments that support the foot. We were also taught about the windlass effect (from Hick's paper).
    The basis of this was Basmajian's article regarding EMG's and the intrinsic muscles of the foot, which showed that the intrinsic foot muscles did not fire when a weight was applied to the knees when the subject was sitting.
  17. deco

    deco Active Member

    Hi Stanley,

    Can you give the details of the paper??


  18. efuller

    efuller MVP

    The Basmajian paper did show muscle activity with very high loads applied. The experimental set up was patient sitting. EMG electrodes monitoring intrinsic foot muscles (and Maybe some extrinsics, I can't remember for sure.) A board was placed on the sitting subjects knee and thigh. Various loads were applied to the board while the EMG was recorded. As I recall, 100, 200 and 400 lb. loads were applied. At 100 and 200 lbs. there was no or very little muscle activity. At 400 lbs there was significant muscle activity.

    This makes quite a bit of sense in terms of the tissue stress approach to understanding the foot. There is a point at which stress in a structure (e.g. ligament) will begin to hurt and the brain senses this and activates the muscle to spread the stress to other strucutres (ligament and muscle as opposed to just ligament.) This is also a good example of central nervous system mediated pain avoidance. If part of the central nervous system is not working, (absence of protective sensation.) then the brain does not know that the muscles need to be activated.


  19. Stanley

    Stanley Well-Known Member

  20. Stanley

    Stanley Well-Known Member

    I think the conclusions that there was no muscle activity in standing or walking was because that 400lbs is not approached in standing walking or running. It can however be approached in jumping.
    In the study, the subjects varied in weight from 152-212 pounds with the average being 174 pounds, so we are talking about over 2X body weight for the muscles to fire.


  21. Here is the full article by Basmajian...it is one of the early classic articles in foot biomechanics and probably the most important one of its era.
  22. At risk of stating the obvious Basmajian's set up was static, extrapolating this data to dynamic function should be done with caution. As I recall, the work of Mann and Inman suggests that the plantar intrinsics are active during the stance phase of walking: Mann, Roger, and Verne T. Inman 1964. Phasic activity of intrinsic muscles of the foot. Journal of Bone and Joint Surgery 46A(3):469-481. Full text of this is available but my hotel's wi-fi won't let me download it for some reason :craig:

    Further, Niggs work suggests that the nature of the force input may be significant in muscle response.
  23. Another problem with Basmajian's research is that the subjects were sitting when the force to the foot was applied. We don't know whether seated posture somehow changes the activation of the central nervous system in response to loads versus standing, or not.
  24. Agreed.
  25. Just realised I never really answered the original point here. I consider that I made a lucky escape. You see as an undergrad I wasn't the most attentive of students. As any of my class-mates back then will testify; some things don't change- I hear my current mentor's sigh. Truth is that back then in the decadence of the late eighties, I was more into Ian Dury's debut album, the first track on Side 2 of the original 12", that was not credited on the sleeve or label; if you know what I mean;):pigs:;) (Anyone remember the Pevensey Road Parties?- No, nor me). I do seem to remember going to one lecture and wondering where the mechanics in the biomechanics was (I'd studied 'A' level physics). Anyway, I memorized what I needed to know to get through my exams without actually learning or understanding anything about the bastardized Rootian biomechanics that was being espoused at the time. Everything was caused by "abnormal pronation" and the solution was a 4/4 posted orthoses anyway (somethings never change;), so if you said this in your exams, you wouldn't be far off the mark.

    Then when I started my PhD after graduating I spent a long time searching the literature (the old fashioned way, working through journals by hand and eye) and found Kevin's early STJ papers in JAPMA which made clear sense as it talked in terms of forces and moments and MECHANICS. I've been following the lads progress ever since :D.

    BTW I didn't actually read R,O,W in it's entirety, cover to cover, until much later (probably when I was sparring with Jeff on the old mailbase :boxing:), by which time I could filter good from bad- I thinks.
  26. Adrian Misseri

    Adrian Misseri Active Member

    Thaks all,

    As a relativly new podiatrist given the current company (graduated undergrad 2003), I have found this thread invaluable. Kudos to Kevin for starting it!
    Having studdied biomechanics at a post grad level, and having discussed a few of these concepts at that time with other podiatrist of varying experience and background has brought me to a rather unfortunate conclusion. As podiatric biomechanics is such a complicated area of knowledge, one that is constantly evolving, it is ridiculously difficult to study and to provide evidence for practice in the clinic, especially at an undergradate level where a student is only beginning to be exposed to how the foot works. Unfortunately, it seems that most people will get some degree of relief from almost any device shoved under their foot, so students and 'younger' podistrists often get away with prescribing devices which really have no rationalle and are often not the most appropriate or correct for that patient. Looking back at my first few biomechanical/orthotic patients, I know I certanly got away with more than I should have, which really, in today's litigious society, is not good.
    Threads like this, with more 'senior' podiatrist like yourselves are crucial for us 'younger' podiatrists in understanding how biomechanics develop and how biomechanics are supposed to work.
    Huge 'thank you's to Kevin and you all!
  27. Stanley

    Stanley Well-Known Member

    Simon, I agree. I was responding to Eric's conclusion from the paper. I was trying to show the weakness in using this paper to support the tissue stress theory. That is not to say that there is no support for it, just that this is not the best article to use for that purpose.


  28. Adrian:

    Glad to see that you have appreciated the thread. From reading your posts so far, you appear to be far ahead of many others in your knowledge of biomechanics and have great potential to excel, given your interest in the subject.

    When I read comments from a young, intelligent podiatrist such as yourself, it makes the many hours that I spend contributing to Podiatry Arena educating podiatrists on biomechanics, orthoses and sports medicine seem very worthwhile.

    Keep up the good work.:drinks
  29. Simon:

    There are few other podiatrists in this small world of ours that have the intrinsic intelligence that you do regarding foot and lower extremity biomechanics and foot orthosis therapy. It is been very gratifying for me over the past decade to have a friend like you to discuss ideas with, do research with and, when the occasion permits, to share a beer or two together. As I enter my second half century of life, and approach my first quarter century of being a podiatrist, I now appreciate these relationships more than ever. Here's to you, mate!:drinks
  30. Atlas

    Atlas Well-Known Member

    Surely the earliest biomechanical theory and that which lay people and inter-professionals (physios, masseurs, chiros) latch onto is...

    "a flat foot is bad"

    The goal of intervention (if it was cureable) was to un-flatten it...with "arch support".

    Why else did many escape army duties in the 50's and 60's because they had the nasty condition of "flat feet".

    Just my hunch.
  31. Cameron

    Cameron Well-Known Member


    At first sight it may appear the French Revolution, Charlie Chaplin, War, Wine and NASA have nothing in common but they do and it is called biomechanics. The term is used more and more in everyday language and has come to mean the study of normal human movement. Patho-mechanics is the technical term for abnormal movement but is often restricted to medical text. At the time of the French Revolution, people, especially poor people, started to matter. The traditional hospitals had been glorified brothels where literally people went to die, usually in great pain and distress. New and increased concerns for the proletariat however meant radical change in health care with the establishment of teaching hospitals. Clinical experts were available to teach as well as practice. In the La Gaze (the beginning of medical specialisation), medics referred to all body systems as biomechanics. Modern interpretation takes rather narrower meaning preferring biomechanics to mean human movement only, but originally this was a term used to describe a complete biological system. Throughout history many researchers have tried to analyse walking but it took to the introduction of cinematography before real insights were made. Even today the strides made in the early 20's and 30's have not yet been surpassed. With the invention of photography frame by frame analysis of walking allowed observation of detail not obvious to the naked eye. The two men most associated with the technique were Eadweard Muybridge and Étienne-Jules Marey and their works are still referred too. Frame by frame analysis helped researchers make special sense of the abnormal human locomotion which had enormous potential for orthopaedic surgery. Anthropometry i.e. the identification system based on physical measurements of the body was created by Alphonse Bertillon a French law enforcement officer. He believed criminals were an inferior species and had physical defects which could be identified by measurement. Not only did he develop the first scientific system police used to identify criminals but also introduced the mug shot and the systematisation of crime-scene photography. Bertillon was the first to include footprint analysis. At is height, anthropometry or Bertillonage as it was known was widely used by French police and in other European countries but it was eventually replaced by fingerprinting. Anthropometry continued to be used by scientists developing growth charts and clothing size systems, and eventually became in common use in sport science. By far the most celebrated person to see a pratical use for biomechanics was Sir Charlie Chaplin who regularly filmed scenes backwards, then to the amusement of millions would show the films unning forward at higher speeds. No one has knows why people find silly walks amusing but the do and made Charlie Chaplin a very rich man and household name. By the fifties, North Americans were conserned at the increasing numbers of wounded veterans returning from Korea then later the Vietnam War. Appalled at the apparent lack of research and development in the science of rehabilitation for amputees and those physically afflicted the public outcry put greater political pressures on the government to introduction of a national rehabilitation initiative. Coincidentally this occurred when North Americans were alarmed at Russian dominance for space exploration. Zillions of dollars were pored into the US aerospace industry and science education in general. During this period it is reported (possibly by Inman?) that on a plane flying to Seattle were two strangers, both on route to attend separate conferences. One was the director for new US Rehabilitation Research and Development Program, the other the NASA supremo. After a few cocktails and the ice broken, they started a casual conversion to pass away the travelling hours. After the introductions the aeronautical engineer rather boldly suggested,

    "Do you know if we made aeroplanes like you make false knees then our planes would never get off the ground?”

    "What do you mean?" came the puzzled reply".

    "You chaps try to replace the knee with something that looks like a human knee whereas we design a plane to defy gravity using the laws of nature."

    That was the beginning of a very long and fruitful relationship between the two men and was also the birth of biomedical engineering or modern biomechanics. They agreed to meet after their respective conferences in a city park and one brought a couple of bottles of wine and the other bread. The aeronautical engineer suggested an experiment that with each sip of wine the friends had they should feed the ducks a wine soaked piece of bread. After several bottles of wine, the aeronautical engineers suggested his companion stand and try to walk in a straight line. The effects of alcohol caused the rehab expert to stagger and when he returned to his seat the engineered observed, “Watch the ducks walk.” Despite consuming the same volume for size of alcohol as the men, the ducks continued to maintain a straight line walking.” He asked his friend to explain why the alcohol appeared to have no adverse effect on the duck’s gait. Once they had agreed there was no significant physiological reason it had to be something to do with the body’s centre of gravity i.e the lower the centre of gravity the greater stability. Imbalance through intoxication caused humans to stagger whereas the broadbase of the dase kept them stable throughout. From that keen observation the science of orthoses and prostheses changed to reflect Newtonian Physics and Momentum Physics with emphasis of three and four (time) dimensional analysis. Combined with cinematography, anthropometry, force and pressure analysis, modern biomechanics has been incorporated into sports science and forms a major part of preparing elite athletes for the Olympic Games. Today, biomechanical analysis helps commentators understand the intricacies of movement that are unseen by the naked eye and also assists sportwear designers to manufacture performance enhancing footwear and swim suits, the effects of which are so eagerly awaited by spectators in expectation of record breaking performances.

  32. Cameron:

    Let's not forget the "Father of Modern Biomechanics", Giovanni Alfonso Borelli, who was mathematically calculating the internal forces within the muscles and joints of the body before Sir Isaac Newton's 'Philosophiae Naturalis Principia Mathematica'. Borelli is well known in biomechanics circles but is virtually unknown to podiatrists. He was indeed a pioneer and should be rightfully acknowledged for his considerable contributions to biomechanics as we know it today. Here is a nice review article for all of you who want a little more knowledge regarding the history of biomechanics.
  33. David Smith

    David Smith Well-Known Member

    Hey boys




  34. David Smith

    David Smith Well-Known Member

    Yes! Caaaalzaagie wins again. CHAMPION CHAMPION.

    UK Rules OK
  35. CraigT

    CraigT Well-Known Member

    Someone should ring Dave on his mobile... do you thing he will answer now?
    I thought it was a strange time for him to be posting- love the dedication though...
  36. Dave:

    How many research articles from 45 years ago studied the electromyographic activity of the plantar intrinsic muscles under load? How many have since? How many before this article by Basmajian? You must consider that biomechanical studies of the foot in the early 1960s were rare and Basmajian was doing something that no one had ever done before you become too critical of a researcher's work.
  37. David Smith

    David Smith Well-Known Member


    Ok I agree I was a little undiplomatic and harsh considering the history, but then I was feeling a little uninhibited at the time, my apologoies.

    How ever it is my opinion that when reporting on experiments using EMG it is very important to be presice about methodology. This report leaves itself wide open to critisism since there are only scant details of methods of data collection, processing and analysis, which is so important for the reader to be able to usefully and reliably interpret the work.

    The main points are. How did they load the device? was the load perfectly still before reading where taken? Was the load 400lb at the loading point or was it at the knee as a function of the lever * force applied? (it sort of imples that this was the case) At what point did the pressure from force applied to the kee become painful and perhaps cause muscle tension.? Was muscular action required to stabilise the load? Where were the preamps fitted, were there any pre amps? What was the pre amp and amplifier gain. The position, type and gain of the amps can make a huge difference to the output signal. Was there any crosstalk? Was there noise? How was noise and crosstalk eliminated or accounted for in evaluation? Where any filters employed in the electronic circuit or in the data processing? What were the filters? What was the baseline output, How does the output signal relate to muscle activity. How does the signal output relate to signal input. There is an indication of signal output scale where it may be compared with the 200ma timing signal. If one looks at a muscle unit action potential signal (MUAP) and it has a relative scale output of 180ma is that clinically significant. What if the amp gain is 200,000. What does 180ma output = in terms of force? 1N or 1000N who knows. Can force be extrapolated from MUAP magnitude. Generally no it cannot. To get an idea of signal magnitude to muscle force magnitude it is necessary to first have some refrence output, often maximum voluntary contaction is used but is not highly reliable. Muscles tend to give higher MUAP out puts at end range of motion but this may not equal max force output. There are large differences between types of contraction. There was no signal to muscle output referencing reported in this study. In my opinion all that can be extrapolated from this experiment is that there was increased signal output with higher loading. Anything else is supposition and interpretation is based on bias not fact.

    Respectfully Dave Smith
  38. Dave:

    All your points are valid. However, my point about this paper is, how many researchers before 1963 published a paper on the electromyographic activity of the plantar intrinsic muscles during varying loading conditions? Don't you think that a researcher deserves credit for making an attempt to do something that no one has ever done before and then taking the time and effort to get it published in a journal? Doing research is one thing. Taking the time and effort to get it published is a whole other beast. For this reason, I still think Basmajian's article is a classic and is definitely worth taking the time to read for anyone interested in foot and lower extremity biomechanics, regardless of it methodological shortcomings that seem quite obvious from our scientific perspective now over 45 years since its publication.
  39. I agree, scientific writing has changed a great deal over the last half century. If one reads the papers contemporary to this work that were published in JBJS (let's face it, one of the top journals) you will find numerous methodologies that are equally scant of detail by today's standards. In terms of EMG, Basmajian was THE early pioneer. If you have never read "muscles alive", you should. Brilliant man. In fact I've just ordered a copy as despite reading it, I've never owned it.
  40. David Smith

    David Smith Well-Known Member


    None as far as I can find and research reveals Basmanjian as a highly prolific researcher and writer. He has written many scientific papers and books in anatomy, Physiology, biomechanics, orthotics, and by far the greatest number are EMG subjects.

    He has papers dating from 1952 The distribution of valves in the femoral, external iliac, and common iliac veins and their relationship to varicose veins.Surg Gynecol Obstet. 1952 Nov;95(5):537-42. to 1994 Physical rehabilitation outcome measures B Cole, JV Basmajian - 1994 - Williams & Wilkins, with early EMG papers such as Electromyography of two-joint muscles. JV BASMAJIAN - Anat Rec, 1957 - and Electromyography of iliopsoas. JV BASMAJIAN - Anat Rec, 1958.

    When taken in the context of this career and if previous papers are read then the paper we are discussing can take on a different light and certainly Basmanjian has been a major contributor to the understanding of these areas of interest. One could understand him not including detail that he has been covered before.

    However it would seem he is somewhat of an expert in the area of EMG and even wrote the article Facts vs. myths in EMG biofeedback - Applied psychophysiology and Biofeedback, 1976 - Springer. It would seem reasonable to expect that any paper written by Basmanjian would be more complete in its reporting and not be so ambiguous. Maybe this is a problem with writing for journals where space and wordage is limited and so reports becom truncated. Often to their detriment.

    I don't believe one can commend a paper simply for breaking new ground if at the same time it is content to let the the content be ambiguous and does not consider its limitations and shortcomings. This may lead to subsequent (perhaps careless or less kowledgeable) readers taking the conclusions at face value and applying them to further research or clinical interventions also without considering the inherent errors, thus compounding the error.

    Maybe it could be considered classic in terms of promoting new thinking in the area of interest but at the same time requires to be taken in the context of his other writing and prehaps this should be made more clear in this paper.

    All the best Dave

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