Prescribing Orthoses: Has Tissue Stress Theory Supplanted Root Theory?

And yet the same "degree" of posting placed a few millimeters more proximally may not have created the same problem since here it would have had a shorter lever arm, thus the moment this wedge created at the STJ would have been less since Moment = force x perpendicular distance to the axis.

This is where the evolution from Root to tissue stress falls short, we are still posting in angles rather than in forces. Angles influence forces in that they impact on the relative magnitude of shear versus vertical components to the force vector, but this alone does not define the vector. For example, we could have two identical foot orthoses with identical angles of posting in exactly the same position on an orthosis, but lets say that one of the posts is stiffer than the other because it's made out of a different material.... Lets say that we have two identical orthoses, but in one the rearfoot post ends 3mm more distally... Lets say we have two identical orthoses, but with top-covers with different co-efficients of friction...

If only it were all about the angles?

If only life were that simple again...

If only I could be that naive again as to buy into a Root based prescription protocol like that attached...

Thankfully I'm not, I'd rather teach the truth- warts and all, than pretending we can accurately measure angles from lines drawn on the back of someones foot and leg and from this arrive at an angular foot orthosis prescription that "holds the foot" in some position and "negates the need for compensation" all the while ignoring the biomechanics of the tissue that is injured, in favour of measuring the "deformities" (for deformites read structural variation), as I was taught. Just my point of view.

 

I too have had plenty of failures. What is nice about the tissue stress approach is that you have a framework for changing the failure. Sinus tarsi symptoms not relieved... Add more supination moment to the orthosis or more supination moment from some other source. Medial knee pain after giving someone a varus heel wedge type device.... less medial shift in the center of pressure.

I remember back in school when an othosis did not relieve symptoms. Our instructors would look for the mistake (e.g. wrong forefoot to rearfoot measurement.) And then make the ortotic the same way, again.

Eric

 

Let me guess... they always got a different forefoot-rearfoot measurement than the one you got, so your measurement must have been wrong! Go figure :hammer: :bash: Nothing to do with the atrocious inter-observer error in that measurement, lack of understanding of the structural mechanics of foot orthoses and the lack of subject-specific, tissue stress specific prescription protocol. Nope, you got the measurement wrong- love it. Worse, I've seen this measurement employed as part of an OSCE in which the poor students were supposed to blindly come up with the same measurement as the tutor- FFS:bang:

 

I agree with Eric. I had the exact same experience at CCPM. One of my professors in biomechanics would, if the orthosis didn't work for a patient, invariably make us recast the patient. His opinion was that if the orthoses didn't work it was because "you didn't take a good negative cast.":bash::craig:

 

Actually, people have referred you to the papers they have written on the subject and then you make comments on how they are using their own papers to support their point. No, they are showing where to go to get a more complete understanding of their point of view. In many of those articles there are pictures that one might find helpful in understanding their point of view.

Matt, you often try and make things personal. Kevin, didn't like it. He's choosing not to engage. Get over it and stop whining about it. Or you could stop trying to make things personal. Attack the idea, not the person.

Don't say that someone is wrong. Say why you think they are wrong. There is literature showing that external knee adduction moment is associated with medial knee arthritis. (A three dimensional finding, that is best drawn in the frontal plane.) Are you saying that literature is wrong? Why do you think that? What other cause(s) of knee problems have you discovered? A lot of researchers discuss their ideas before publishing. It's not spilling the beans.

Compensate is a word that I've come to see as a red flag for when someone may not know what is really going on. How does one compensate to resist supinatory moments? How does being at end or range of motion of pronation prevent this alleged compensation? Does irregular terrain always produce supination? If not why not? (can be explained by STJ axis position and location of center of pressure) What forces from above in closed kinetic chain will create a supinatory moment? To describe a force you need to know which object is applying the force and which object the force is being applied to. You also need to know the magnitude, direction and point of application of the force. You don't always need all of those things, but if you are not using them, you should be able to explain why they are not needed.

Matt, in your videos, just showing that the motion occurs is not as good as explaining why the motion occurs. If motion occurs a force caused that motion. If a rotation occured a momnet caused that motion. So, don't leave out the forces and moments if you expect your video to explain a particular event.

Eric

 

I remember when I was a first year I was observing a third year in clinic take some negative casts (Plaster of Paris). The lecturer walked in afterwards (had not been present during any stage of the cast capture), looked the the casts in his hand, looked at them sitting on the table, and then told the third year to take them again as the foot wasn't in neutral when the cast was taken....

 

At CCPM we once had a practical exam and for a little bit of fun I thought that I would ask the students to measure forefoot to rearfoot. Beforehand, I decided to grade them on putting the tractograph in the right place to make the measurement. There was a 15 degree range in the measurements. As I recall the measurements were fairly evenly distributed across that range. So, it was more variable than the time that I had participants at the Weed seminar do the same thing. There was only a 10 degree range there. However, at the Weed seminar, I wasn't succesful in preventing the participants collaborating to come up with a number. There were many who were not confident in their measurement being right.

Eric

 

I just took new pictures of his orthoses under his feet again. Mild blanching was evident but different than original location. I know my lab makes much tighter conforming heel cups than most labs. I think most labs use too much heel expansion and as a result, error on the side of comfort over functional control. These devices are totally comfortable.

This individual is an employee of mine. I had noticed in the past that he is highly pronated but I had never examined his feet nor had I casted and made him orthoses until a few weeks ago. I did so because I wanted to use his feet in lecture I was preparing and also for the purpose of teaching students who were planning to visit my lab. I also had no previous knowledge of his medical history.

When I originally examined his feet for my project, he was basically asymptomatic. He said he knew his arches collapsed but he didn't report and real symptoms. Matt Sciaroni asked me to ask the patient if he had a history of growing pains, which he denied. Matt requested that I have him ask his mother about growing pains. I witnessed the phone call in which his mother informed him that he had growing pains and that she had to rub his legs at night as a child. He had no recollection of this history.

You may also recall that I indicated his MTJ was unusual and hypermobile. He has one of those feet that easily supinates and pronates away from STJ neutral when you apply a dorsiflexion and a simultaneous adduction or abduction force to his forefoot. Bear in mind that I was never initially doing any of this to treat him. Today when I reexamined him to check his heel blanching, I learned some interesting history which I will share in a moment.

When I originally photographed his feet and orthoses a few weeks ago, I noticed that his traditional Root devices conformed well to his feet but the devices made from the same cast that was inverted 5 degrees and had a 3 mm medial heel skive, gaped away from the distal aspect of his 1st met (see stance and non-weightbearing photos of this). This inverted device is comfortable in the medal arch but is uncomfortable in the area of the medial heel skive and there is noticeable pressure (blanching) in this area. So in spite of his collapsing medial arch, the uncomfortable area is in the heel and not at the bony prominence in the arch as one might have expected.

Today during my reevaluation he informed me that he has Aarskog syndrome, which apparently can cause joint hypermobility. For the record, he gave me consent to share this aspect of his medical history on the Podiatry Arena. Now, the foot function makes sense given this history. He also reported that prior to wearing orthoses he had an intermittent shooting pain from his right foot that shot up to right hip. He said that it has not occurred since he has been wearing orthoses. Interesting case.

Jeff

 

Given that angles of posting do not correlate directly to forces produced- why do we need to measure angles at all?

 

Note: The inverted device has a black vinyl top cover and the vertical device has a bronze colored top cover.

 

Given that angles of posting do not correlate directly to forces produced nor to angles of positional change observed in the foot when the angular wedging is applied to it- why do we need to measure angles at all?

 

Eric,

A picture is worth a thousand words. I can tell you I have prevented compensation and you would have to take my word for it. I posted pictures that show my orthosis has redcued heel eversion, internal leg rotation and has increased the medial arch height. I posed pictures to show he is compensating without orthoses and that I have reduced compensation with orthoses.

Jeff

 

And a scientific study is worth a whole lot more...

Nope what you can say is that the foots position in static stance was changed with the orthoses, let's loose the silly vernacular. Did the foot position change with both foot orthoses? Did the blanching on the left heel reduce because he leant more to the right for the photo this time?

What's interesting is that your static photo's appear to show positional (kinematic) change with the devices in isolation. The classic study of Williams et al. showed that neither Root nor inverted devices signficantly altered the rearfoot kinematics during dynamic function, but that the inverted devices (the ones that made the patients better in this study as opposed to the Root devices which didn't) showed a significant difference in terms of the kinetic variables but not the kinematic variables- Viz. kinematics may not predict orthotic outcomes.

Griff, why don't you post up your pictures of Vic standing in the orthoses here- then explain how you obtained the photographs so that we stop being so naive about photography on this site.

 

There are also significant changes in his gait. His feet are less abducted, his medial arch doesn't flatten as much and his tibia doesn't internally rotate as much. So these devices produced graphic changes in static stance and gait.

I believe he undergoes compensation due to a hyper mobile MTJ which is clearly addressed while wearing orthoses.

Jeff

 

John 11:35

 

Proverbs 27: Let another praise you, and not your own mouth; a stranger, and not your own lips.

 

Thanks, Jeff, for showing that someone can know what they are talking about when they say compensation. You described specific motions at specific joints. Some use the term compensation without thinking it through.

Eric

 

Regarding the picture below which of these two statements is true:

(1) The device corrects alignment and prevents compensation. It clearly reduces calcaneal eversion excursion, stops medial arch deformation and this patient also shows significant gait changes. The patient reports marked reductions in symptoms when wearing these devices.

(2) I asked my wife to maximally pronate her left foot and took a photo. I then positioned her foot ontop of a device (not even hers but a sample that a lab gave me) and took a photo of it again while she (and her Tibialis Anterior) held it there for me. I drew on some dotted lines and put the two pictures next to each other. These pictures tell us absolutely nothing about her forefoot to rearfoot relationship, her current pathology (if any) nor her risk of developing a future pathology (if at all).

 

On the other hand... some people use compensation to describe when the foot moves away from the idealized neutral position. If you were to put the foot in this position the foot would sit markedly inverted, with the lateral forefoot on the ground and the medial forefoot up in the air. In this case the center of pressure is lateral to the STJ axis and this will cause a pronation moment and there will be a compensation from this idealized position.

However, in real life a foot may never be in neutral position. If a foot is never in that position can it "compensate" away from that position.

So, in Jeff's case above, is this compensation, or is this just a very compliant midtarsal joint? What is the compensation?

From dictionary.com

noun
1.
the act or state of compensating, as by rewarding someone for service or by making up for someone's loss, damage, or injury by giving the injured party an appropriate benefit.

2.
the state of being compensated.

3.
something given or received as an equivalent for services, debt, loss, injury, suffering, lack, etc.; indemnity:
The insurance company paid him $2000 as compensation for the loss of his car.

4.
Biology. the improvement of any defect by the excessive development or action of another structure or organ of the same structure.

5.
Psychology. a mechanism by which an individual attempts to make up for some real or imagined deficiency of personality or behavior by developing or stressing another aspect of the personality or by substituting a different form of behavior.

Eric

 

Apples to oranges. My subject had his heel bisected while the STJ was held in the neutral position. He was asked to stand in his angle and base of gait. Pictures were taken of his feet and I had him lift his heel and I slid his orthosis under his foot without changing his angle and base of gait and I took more photos. I then had him turn the other direction and I repeated the process and took photos from the posterior view. I then repeated this entire process with a second set of orthoses to compare the difference between the two different orthotic Rx's.


Today I took another set of pictures of his heels without a bisection line. Even without the benefit of a bisection line, you can still see that his rearfoot is close to vertical as compared to his previous photos that were taken without his orthoses.

Jeff

 

The point that I believe Ian is trying to make is that the showing of photos of a person standing with and/or without foot orthoses is meaningless from a scientific standpoint and/or from a medical evidence standpoint due to:

1) a photo is a static analysis of foot position, and
2) the patient may use the extrinsic foot muscles to reposition their foot on the orthosis any way they so desire.

I would be much more impressed with a pressure insole (e.g. E-med, F-scan, RS Scan) analysis with and without orthoses during static standing...at least a pressure insole is measuring force, and not just position.

 

Referring to one's own paper to support their own ideas is NOT good medicine, Eric...and you, as well as others here should know that. Kevin thanked you for your post, so he's reading mine as well. I asked simple questions. He was the one that made our "relationship" personal, not me. (Even Darryl Phillips reacted negatively towards Kevin and hasn't been seen from since that time for all intents and purposes). Yet you inform me to "get over it". I'm LMAO at your unwavering support of Dr. Kirby. Perhaps it was when I informed him that the statute of limitations for defamation of character is now two years in California, that he "saw the light". N'est ce pas? Wait until he sees whom co-authored the paper being published. That ought to be a hoot.

OK...so I'll ask you the same question...how does a lateral skive to the rear post help a person that is already functioning at their end of ROM in eversion? Further, even the orthos have "backed away" from the valgus forefoot extension to treat medial knee DJD, (notice I didn't call it OA?), yet several of you are "lock and loaded" on these forums as believing that is the truth. I've already informed you that I will release the videos when they are produced and edited, but I'm not really sure why I would here, given the "warm" reception I've been given.

You wrote: "Compensate is a word that I've come to see as a red flag for when someone may not know what is really going on." Really, Eric...do you REALLY want to go there? Obviously so. I read your chapter on tissue stress in Albert's book. And all I have to write is poppycock and balderdash. Trying to re-invent the mouse trap is not helpful, especially in medicine....fine tuning a theory that has been in existence before, tweeking and defining that theory, certainly is. Those videos I produced previously were targeting primary care physicians...MD's and DO's, to bring them up to speed on foot function. Previously, and even still, I have yet to witness ANYONE'S videos depicting STJ motion to the extent my animator presented...yet all you've done is slam them for not describing in enough detail WHY the foot functions the way it does, (although I did), and that you didn't really learn anything from them, because: 1) you've seen some fluoroscopic study on feet, and 2) you knew all of this already. The answer to the riddle of growing pains in children and the anatomic/pathologic tie to RLS in adults was staring you right in the face, and it appears you still haven't figured it out. I used Root biomechanics to describe the problem and how to correct it. You get over that. Once the article is published, you can use tissue stress theory to describe it to others...doesn't really matter to me. My goal is to accurately determine the cause of a problem and in the process help millions of patients. What's yours?

 

Which technique can be used by any podiatrist at any time? The one I demonstrated. Do you have an F-scan or any of these systems in your office Kevin?

Jeff

 

I don't have any pressure measurement system in my office. That is not the point.

The point is that showing someone standing on an orthosis proves absolutely nothing, is unscientific and seems to be used only when someone wants to advertise their foot orthosis products on the internet.

 

It clearly demonstrates the moments acting on the foot resulting from the orthosis. I casted the foot in a specific position and wrote a specific Rx to address this very pronated position of the foot. You guys believe in the "magic moments" that can't be observed and deny those that can. Really?

Jeff

 

As I stated earlier, just because a foot appears to be positioned differently on an orthosis may be due either to and alteration in external moments from the orthosis or by an alteration in internal moments from activation of the extrinsic or intrinsic muscles of the foot.

How do you know, Jeff, that the change in foot position seen in your photograph isn't due to your subject using his muscles to supinate his foot to please the photographer? Answer: you don't.

Funny, the rest of the International Biomechanics Community uses the term "moments" routinely in their scientific publications since it is precisely defined and quantifiable. However, now I'm being derided for using commonly accepted scientific terminology and then I'm being told that taking a photograph of a patient standing on an orthosis is somehow scientific?!

Very disappointing.

 

I will bring him to your office and prove it!
Jeff

 

I agree that the concept can / has / is being taught, that is clear. Furthermore, with a good underpinning of knowledge, the principles are straight forward. It of course requires an excellent knowledge of functional anatomy. You make good points regarding ZOOS and grading orthoses.

However, with a well-defined model, we should be able to predict or at least consider the stress we place elsewhere. Eric refers to this as redundancy in the article he wrote on CoP. I believe the issues are well highlighted by the other quotes below.

This is a great example of the potential issues and, to me, the key is how one predicts the outcome as Eric alludes to in the last sentence. When we isolate just to pronation and supination moments it makes an assumption that everything above the foot is functioning normally – what if the foot has a tendency to pronation but the tibia is not rotating, this is difficult to assess on any clinical level?

In this paper that Simon refers to, the authors did not find any change in rearfoot eversion kinematics but did find some kinetic changes as he commented. However, they did find significant changes in tibial rotation, knee adduction and knee abduction moment – so, both kinematic and kinetic changes more proximally with the inverted orthoses.

I agree with Kevin. I have the luxury of having both an inshoe system (Pedar) and 3d gait analysis system in my clinic. The inshoe system I have had for 20 years and I have found it fundamental in assisting my practice – accepting some of the limitations when using over contoured surfaces. The addition of the 3d system has been somewhere close to a revelation to me, actually seeing the more general effects of intervention.

However, this is not available to everyone and I feel that trying to provide guidance as to how the whole system interacts will allow us to be more predictive. Applying the tissue stress approach to an injured structure should allow it to resolve and orthoses are part of this equation. However, this may not be normal function (or perhaps less abnormal would be more accurate – I think you were spot on with your article on the normal foot Kevin) and needs consideration – short term versus long term – how do we predict or model?

If we can provide a framework for this, then I believe we will really be making progress.

 

What about a reverse Thomas heel ?
Daniel

 

The problem with the idea of "normal" function is that it is obvious that normal function is unique to the individual, specific to the locomotor task and to the environment at a specific point in time. This is predicted by the equation: P = G + E + (G * E) + i where: P is the measure of function; G is the genotype, E is the environment (all non-genetic factors) and i is the measurement error. Since we don't know what normal function is for each individual, we cannot measure deviations away from this. Applying a population mean does not resolve this problem.

Probably the simplest way to model is to employ a quasi-static free-body analysis.

 

Yep, similar idea.

 

Again....a bunch of garbage! While Kevin seems to have no problem with Simon showing pics of his patients' feet in static stance, proving whatever, he vilifies others doing the same? What a picture "proves" while standing on an orthotic is the attitude/alignment of the foot at one moment in time during the gait cycle, (is that the proper use of moment?)....ie., mid stance. It is at least as scientific as someone using their own, non-peer reviewed newsletter correspondence to prove a point about biomechanics. Refer back to my second video when I articulated that animation can be made much more accurate while measuring Talar adduction of a foot inside a shoe. That would make the sequence less of "an artists' rendering", and more "scientific" in the eyes of the more critical, if not hypocritical.

 

Interesting and Odd discussion once again

We were taught something or rather part of our teaching we were told this ( bearing in mind it was circa 1993 in New Zealand) that Root et al finished their books and went to an engineering friend to read the book, he read it and said something along the lines of very interesting but some of it breaks the principles I have been teaching to engineering students for the last few decades.

Now as a student I just went along with it and though that the foot is different , but now looking back with 20/20 hindsight and all that How can it - physic principles rule our word It should have been a massive red flag

Of course the above could be an urban myth someones cousin´s dog heard which became fact.

But now days is confuses me silly why the dictionary of Bio- mechanics in Podiatry is meant to be different from the world of Mechanics?

Of course a rhetorical Question it should not be Moments, lever arms , axis etc etc should be the terms of mechanical discussion.

Which then brings us to why people seem the need to hold on to ideas which have been shown wrong. and ignore ideas which is at it´s base simple

ie

diagnosis what is broken

reduce loads on broken tissue to allow it heal.

I then start to think what would Root et al think and say if they were alive today, They seemed very smart men, my thoughts is they may have even written or said, At the time Normal and abnormal biomechanics of the foot Vol 1 and 2 were at the leading edge of biomechanics, but science has moved on ( maybe they would not have, I have no idea really ) but I do wonder why the passion to hold on to ideas while at the time amazing, brilliant and eye opening but 40 years later have been expanded on or shown to be wrong.

Surely the best way would be to hold the 2 volumes as an amazing achievement that they were and look at what is the way forward, the rest of the biomechancis community use Mechanics and do not mention Normal surely we as Podiatrists should as well?

As another side not we are not alone of course

The P&O over here do 2nd level engineering maths are part of their degree, looking at moments, forces etc so they understand how prosthetic legs and feet work, but a 5 week foot course where they make full length EVA devices with a met dome and a FF varus wedge for every patient, no diagnosis required

Anyways some ramble from me as usual I am happy to have moved on from Root, sure it makes the day more of a challenge, but most of my patients are the one who fall through the one size fits gap of the P&Os and I would be in a great many cases making them a lot worse by dealing with their " bad " position and "bad" pronation rather than fixing what is being overloaded by reducing forces

 

Kevin,

In the interest of academic discussion, are you willing to accept my offer to take this patient down to your office so you can observe and examine the results that I demonstrated in the photos and then report back here on the PA that my photos are in fact accurate? I have no problem with the use of the term moments but I'm glad I landed my jab square on your chin in order to get your attention. You examine a patient's STJ axis location and then photograph or make a drawing to illustrate the axis location and you expect others, including me to accept your results. I carefully place a patient in his RCSP (a very accepted technique) with and without his orthoses and I photograph the change in the angle of his heel bisection and then you and others suggest that I or the patient faked the change in the angle of his heel "like those who use the internet to sell orthotics". And you think my comment about magic moments is disappointing. Can't you see how insulting your comment to me was (questing my professional integrity)? Are you so bent of discrediting anything related to "Root theory" that you are incapable of acknowledging my results?

I spent a substantial amount of my time taking these photos and posting this information. I originally did this simple experiment on this subject at my lab in the presence of three CSPM students and a PhD kinesiologist from Samuel Meritt University who were at my lab in conjunction with a pending research project at the new Motion Analysis Research Center at the university. They we so impressed with the changes they saw, they took photos of this subject and videotaped his gait changes. That is what inspired me to take these pictures and share them and the results here.

I find it very sad that this group of highly respected podiatrists on the PA, including you, Simon and Trevor are so unwilling to accept things which do not fit with your biomechanical agenda. What good is this forum if you are so close minded? Other highly respected podiatrists have told me they don't participate on the PA because it is just a place for a certain group of individuals to pat each other on the back. Why is it that virtually no other U.S. podiatrists regularly contribute here?

Feel free to challenge my technique, my methodology and my conclusions but please know that when you challenge my personal integrity, which you did, you have crossed the line. I hope you will accept my offer to see this patient for yourself since you seem so skeptical. I would think that changes like this would be of no surprise to anyone who has used properly made functional type foot orthoses which is why I am so surprised at the negative reaction to my photos here. It makes me wonder what kind of results others get with their orthoses if this simple demonstration of positional chances is so incredibly unbelievable.

Jeff

 

Mike,

They stopped writing the book to do cadaver research on the concept of an osseous restraining mechanism at the MTJ. Their research proved my father's theory wrong and that the MTJ relies on soft tissue compression for stability.

The authors had Dr. Milton Willie, Professor of Mechanical Engineering at Brigham University review the book and he wrote the first section of chapter II, the Mechanics of Foot Motion and Stability of Joints in the Foot.

Jeff

 

Mike,

We have all moved on (progressed) but there are components of Root theory, Root examination technique, Root casting, Root terminology and Root orthotic fabrication that are just as much a part of todays podiatry and biomechanics as they were forty plus years ago. Tissue stress theory doesn't replace Root theory, it augments it. And yes, there are components of Root's work that have been or still need to be replaced with a better model or approach. And let's not forget, Tissue Stress Theory has a lot of room for improvement, development and advancement.

Jeff

 

Jeff:

Sorry if you felt that my posting questioned your integrity. I feel you have the highest professional integrity, Jeff. That was not at all my intention of my post.

The point I was trying to make, which I suppose got lost somewhere in the translation, is that when you place a foot on an orthosis and see a change in foot position, it is possible, that the person standing on the orthosis may be changing the posture of their foot to "please the photographer" or that the instant that the photo was snapped that the captured foot posture is not an average foot posture of the subject's foot resting on top of the orthosis. In other words, not only is it possible that the foot orthosis "pushed" the foot into a different position, it is also possible that the subject's central nervous system chose to activate any number of the intrinsic and/or extrinsic muscles of the foot to put the foot into a different position at the instant in time the photograph was taken.

Now, in your case, did I think you told your subject to stand differently or try to "fake" the photo? No.

However, is it possible that the subject you photographed knew what you were trying to show and subconsciously or consciously fired some of their intrinsic or extrinsic foot muscles to position their foot differently at the instant the photo was taken? Yes.

Therefore, regardless of who is showing these photos, whether it is you, or Simon, or Ian or Trevor or anyone else anywhere on the internet, I believe these types of photos are all quite unscientific, for the reasons I have given above, and I pay them little attention.

So, Jeff, sorry if you misunderstood my post as questioning your integrity since that was not my intention. I am solely questioning the scientific validity of showing photos of patients standing on orthoses and assuming that the instant that the photograph was snapped that the foot position seen on the orthosis is representative of the average foot position on that orthosis or solely due to the direct mechanical effects of that foot orthosis.

Here is some further reading on this subject from my fourth book for those who would like more insight on this topic (Kirby KA: Foot and Lower Extremity Biomechanics IV: Precision Intricast Newsletters, 2009-2013. Precision Intricast, Inc., Payson, AZ, 2014, pp. 53-54).

Direct Mechanical vs. Neuromotor Effects of Foot Orthoses

 

Sure Jeff Never said Tissue stress was perfect, the one big problem is knowing how much force to apply, and that is where the art is working practically will always have a degree of "art" when it comes to devices, or casting and while there has or may have been developments in Root theory I am very sure that you don´t need to have heard of Root to use and understand the science of Tissue Stress Theory - you need some basic Physics to, and a sound understanding of Anatomy

Maybe it is a US thing when you say

which is fine, but I disagree it might be in the US or Pods you work with but as I said further up you do not need to have even heard of Root et al to use Tissue Stress theory

 

Thanks for that Jeff see my story was more from the cousins Dog

 

"Therefore, regardless of who is showing these photos, whether it is you, or Simon, or Ian or Trevor or anyone else anywhere on the internet, I believe these types of photos are all quite unscientific, for the reasons I have given above, and I pay them little attention."


Kevin-Is that why you posted pics of your step-daughters' feet? And was that Newsletter from Intracast peer-reviewed?