Prescribing Orthoses: Has Tissue Stress Theory Supplanted Root Theory?

Nope, it's not. Tell you what, rather than posting your customary reflex jerk orgasms, why don't you actualy stop, reflect and think about these things before you hit the reply button. Answer: because you don't understand biomechanics and as such you are incapabe of discussing this subject. But you do have a warehouse full of insoles to sell before you can retire. But, but, but but, jerk...

 

Nope, it's not.

Nope, you're wrong!

 

That's how external moments work Hunnibun, if i push on the left side of your nose at right angles to it, it will create a moment about your very brass neck which wants to rotate your head towards the right, It may or may not rotate your neck depending on the size of the counter moments acting to push your head towards the left. The vica versa is right as well.

You didn't ask about supination, you asked about supination moment- you don't understand the difference anymore than the Kipper does, do you Hunnipi.3.1415? ......

 

You appear to have cum too soon Dr Kipper. Premature reflex jerk? Go away and think about it, the pair of you.

 

Dobbs

I can't help you, when you don't know what you don't know.

 

ROFL! Oh you are simply too much, Dobbs. I'd send you a shovel but you're doing quite well at digging yourself in deeper. Heaven forbid we discuss anything real, germane, pertinent or solution based. Nope...in the world of sub-genius, one is forced to baffle with BS...discuss the obtuse, the vague, the less relevant.

Let's see...the opposite of pronation is, (drum roll please)...supination...but NO...the TST adherents want to discuss "moments". Forget the normal...disregard the abnormal, ignore foundational measurements...and please, please, discuss in terms so vague that no one else can understand, with concepts so obscure that it never solves anything...it's all fair game in the world of sub-genius. And when in doubt, the true sub-genius adherent name calls in lame attempts to mock others.

Truly, a double-standard exists at PA. I've written it once, Dobbs, but I'll write it again...let me know when you're ready to discuss biomechanics on a level greater then sub-genius levels. TIA...

 

Let me type this s..l...o..w...l..y that you might understand: there is a difference between a "moment" and a "motion". You specifically asked about supination "moment". You clearly don't understand the difference between "moments" and "motion" anymore than you understand the differences between your arse and your elbow, Honeybun. This is high school physics, yet you are incapable of comprehension. No alarms and no surprises. The only frightening thing is that if we were to give you a gun, and in our country- we could, you'd work out how to pull the trigger by process of elimination...

13 year olds around the world are face palming themselves right now at your lack of understanding of basic physics, meanwhile the biomechanics community are ROFL at your lack of understanding. Never going to make it on X day with your sales to date- must try harder honeybunny1- AKA, Elmer Fudd.

 

previous quote from Eric to some student?

It is not the motion of pronation that is the problem. It is the stopping of pronation that is the problem.

As long as traditional technology continues to try to “stop” pronation (a dynamic fluid motion), with bracing of rigid and semi-rigid engineering feats of marvel!

trying to brace the internal motion of the foot with external devices such as yours, Your technology will never ever, ever be a respected scientific medical tool. It doesn't work well enough, it never will!--there's no principles of science that will back up your technology.

So, when Kevin gets back, you guys will go into closed meetings to discuss an archaic technology and hope to make it better. You know, that's the definition of insanity—doing the same thing over and over and expecting different results!!

 

Dobbs

3) please explain how a "supination moment" occurs in the gait cycle after mid-stance

Other than at heel off, there is no other supination moment in the healthy gait cycle, barefoot or with a traditional orthotic technology.

Any theory that says something else is bunk.

 

Saw a patient today who complained about his foot "giving way" when he stood on it. Both of his peroneal muscles were 2/5 in strength. When asked what giving way meant, he demonstrated maximum inversion of his foot. His forefoot to rearfoot, to my eye, was perpendicular. So, those of you would treat based on forefoot to rearfoot measurement can choose anywhere from 5 degree varus or 5 degree valgus for how you would treat this foot. In stance his heel was vertical. I couldn't do the maximum eversion height measurement because he had no peroneal strength.

Should his prescription be to give him an orthotic that would push him toward neutral position. Is neutral position more stable than resting?

He felt more stable after a valgus wedge was placed under his sock liner. So, yes TST has changed how I would prescribe for an orthotic. Ordered an afo with hinged ankle.

Eric

 

Eric

Here's an example of how technologies differ. You described exactly how to minimize this pt's inversion, by everting and holding him, hoping to stop, but really will minimize his inversion motion? Correct?

Frankly, there was more information I would have liked, but I have a feeling, the pt felt more stable initially, because that position is what he's used to. This pt might be more difficult even for me to fit, because it sounds like a chronic condition from chronic lack of support..

Presuming I have this pt fit properly, I think you'd see, more likely a more vertical heel. Regardless, when you talk about using 5 degrees, that's like 50 different Rx for me.

This is just guesswork on your part when you are using such a wide margin parameters from which the foot works within. My parameters would need some kind of laser measuring, to see how much the planes of motion might have changed.

 

I would want his complete history, age, occupation, etc. History of inversion ankle sprains? I would also like to know his STJ ROM (amount of inversion and eversion) relative to the distal 1/3 of leg and how much tibial varum might be present and his RCSP . I would also want to feel his STJ axis position (high, low average?). If he has a low axis, there will be more inversion and eversion of the heel with STJ motion. Cavus foot type?

Jeff

 

Jeff

I think that was essential information. I thought that too, I still feel with the information at hand, my summary was fair.

 

Eric-can you provide a lateral WB X-Ray pic on this thread? Two things come to mind:

1) What is the forefoot to the ground measurement in neutral position? Remember, the hallux has to obtain contact with the supporting surface, so if the orthotic does not bring the ground up to the great toe, the patient will either continue to collapse in propulsive phase of gait, or adduct the knee.

2) This sounds like a classic case of a rearfoot varus deformity...in other words, this patient has no eversion available at static stance. This patient is maximally everted at RCSP just to get the calcaneus to vertical. If this patient had a high calcaneal inclination angle, then I would anticipate that the "bullet-hole" sign, (or 'see through sign), would be obvious on lateral view. The next time you see this patient, ask him/her if they had GPs as a child, (if they can remember), or if they have RLS, (diagnosed or not) at rest.

One of the first patients I interviewed for the GP/RLS article was laterally unstable...in fact he had shredded the peroneal longus tendon which I had to address surgically prior to orthotic control. The orthotics I made him inverted him towards a more neutral position. He had GPs as a child, RLS as an adult that was so bad, they began before he went to bed. He was taking ropinirole for the discomfort, which I had him stop 30 days prior to orthotic intervention, (reality is that it didn't really work anyway). He is now symptom free and no longer in need of any medication. He has lost >60 lbs and is a new man.

If you happen to see this patient again, try to schedule them later in the day, and try pressing on the sinus tarsi and/or posterior facet of the STJ from laterally. I predict that the patient will be symptomatic.

 

Dobbs...LOL...you never fail to disappoint me. While the rest of us are solving serious problems, you can't even describe how one measures a supination moment...but surely you can, huh, Dobbs? It appears SO incredibly important to your existence, I'm sure you've thought about this before, right?

Your tirades against me have stooped even below your own norm...to the point that sub-genius can no longer be applicable when describing you. The name calling, the bitter attacks, the insinuation of superiority...you demonstrate the whole range with this one post alone. Congratulations, Dobbs...you've been summarily dismissed.

 

Post 642

Eric

, I don't believe I saw this post


Originally Posted by Dennis Kiper
Eric


So, when the fluid moves around it creates "accurate" forces?

The fluid doesn't “move around”--it is displaced under pressure to the areas of less resistance and greater need.
Dennis, you can continue to insult me, I don't care. If you wanted to show other people you know what your talking about you would answer the question.

How do you know that some areas have greater need than others?

There is really no difference between move around and displace.

Eric

I thought you might have just been rejecting fluid technology on a personal basis. From your questions, it is apparent, you really do not have a full grasp of how this technology works.

When fluid “moves around” or is displaced, it is to absorb forces, it doesn't “create accurate forces”--is there some formula that you know, that evolved from this question??

How do I know some areas have greater need?? Eric, it's the structure of a foot to absorb shock and carry us as smoothly as possible. Each foot has various sizes, ROM, hypermobility differences and angulations of the structure. The planes of motion are different even between the L&R of a sgl individual.-- pronatory forces and wt bearing forces of each foot varies slightly, therefore GRF are different (but the pattern is close to the same—the biomechanics may vary by a very small amount of motion and other things.), those differences are hydro-dynamically filled in based on the Archimedes principle of displacement. I'm sure you could find this information in a high school science book.

So, technically, there IS a difference between “mover around” and “displace”.









Originally Posted by Dennis Kiper
Where are the forces applied and how is this different from the forces applied by a solid plastic orthotic? How are these more forces more accurate?

With fluid tech, there are four areas of loading forces, with static tech (traditional tech) there is only one loading area.To answer the rest is too complicated for you. You have to understand more, before you can move on to the other.
Dennis are you talking about the interface between the orthotic and the foot or the orthotic and the shoe?

First of all, the forces applied biomechanically are through the interface of the orthotic on the floor and the foot. That's how it works. The fluid serves as an intermediary between the plantar surface of the foot and the floor (of the shoe)--what makes it different from solid plastic are several.
1-there are 4 areas of loading biomechanically the dynamics of stance phase as opposed to one loading area with a plastic ortho.
2- the fluid orthotic, moves with the foot, --guiding the foot, biomechanically, just the way we have studied the way we would want it to move.--a plastic orth is just what Dr Schmidt used to refer to orthotics--”shovels”--it resupinates the rear foot and midfoot at midstance phase of gait.--the fluid orthotic, decelerates pron and the rearfoot never exceeds “neutral”, because when the fluid is fully displaced from under the heel, it has filled the arch to an “equilibrium state” of stability—the STJ is already loaded, by the time, the equilibrium state is reached!


Dennis, you could show that you know what your are talking about if you answered the question for others. Where are the forces applied and how is this different from the forces applied by a solid plastic orthotic? How are these more forces more accurate?

The “forces” are generated by Newton's 3rd law of physics—every action has an equal and opposite reaction.-- The mets load and decelerate at the forefoot, the pressure of the ground (Newton) is pushing back—THAT'S WHERE THE FORCES ARE APPLIED.

How is it different and why more accurate?---dumb and dumber



Originally Posted by Dennis Kiper
Dennis, the standard definition of plane of motion makes no sense in the above sentence. What do you mean? Neutral position of which joint(s)? Why is it good for a joint to be in its neutral position? How do tell the difference between overpronation and regular pronation? More ..... Marketing

I can't believe this question is coming from a scientist and colleague.
Why can't you believe the question? I believe that you don't know the definition of term "plane of motion" or you would not have used it in that sentence that way. People will think that you are just trying to baffle them with ...... marketing if you can't explain the terms that you use. If you would rather belittle the people that ask you questions rather than explain your technology why are you bothering to post here?



What do you mean? Neutral position of which joint(s)? Why is it good for a joint to be in its neutral position? How do tell the difference between overpronation and regular pronation?



Neutral position of all joints or at least that the axis of the joint is through the center—providing as close to congruency as possible. You don't know why this is better??
dumb and dumber

the difference bet regular and overpronation:

regular pron is normal motion
over pronation: When the axis of a joint breaks the plane of stability or the joint has reached its end of rom.

ANSWERED
Dennis

 

Foot started feeling unstable 2 years ago. Was fine before that. Was told by neurologist that he probably had a stroke. He does not recall any event. Had no problems with inversion sprains before that. He has between 0 and 3 deg tibial varum. Calcaneus to leg max inv 25 deg. Max evers 7 deg. Average arch height.

Jeff, how does the answer to any of these questions change the prescription. If his heel was inverted in RCSP and you calculated that he was maximally pronated at that position would you balance the heel bisection of his cast inverted even though his chief complaint was lateral instability and he has essentially no strength in his peroneal muscles?

Eric

 

X-ray was not taken. What findings would change your prescription and why?

I did not assess neutral position in stance. From looking at everything else I would assume that his medial column was off the ground like everyone else I tested when I used to this test. How often do you see a foot where the medial column is not off of the ground when the STJ is in neutral position? Pronation is not this guys problem. He has had several falls because his foot gave way.

We went around this stump once before. You never came up with a logical explanation of why a partially compensated rearfoot varus would tend to cause lateral instability. Do you think that his instability might because he has no peroneal strength?

With palpation around the reafoot no pain was elicited. I'm sure if I pressed hard enough he would have said that it hurt.

Eric

 

Eric-I burn a LOT of film on my patients...it gives me an idea of "what the foot is doing" at static stance, ie., the arrangement of the forefoot, MTJ and STJ at midstance. It also is nice to throw on the viewbox and use as a tool to explain conditions.

A partially compensated RF varus is not unstable...it's only when there is no eversion available at RCSP, that the peroneals can't counteract closed chain forces, either from below or above. If your patient had any eversion available at RCSP, then he is not uncompensated. I'm assuming he does not, based solely on your history of lateral instability. When you write you "pushed around the rear foot"...that does not indicate that you palpated the sinus tarsi or the posterior facet of the STJ.

If the medial column is, indeed, off the ground in NCSP, then there's something else going on with this patient...but without more info, I'm not sure. Perhaps the forefoot to rearfoot isn't what you claimed? WB X-Rays in the AP and Lateral view would be very helpful.

Why are his peroneal muscles weak? Has he experienced inversion sprains of his ankles so often that they are partially torn? Is there pain along the tendons course?

Indeed...pronation is not his problem, he doesn't have enough...and it's the fact that at maximal pronation he barely gets to vertical and has no ability to use the peroneals to evert the foot further to counteract closed chain forces. The patient is therefore subject to inversion sprains.

One other thing...by adding a valgus wedge, did it ever occur to you that this might aid the patient in bringing the hallux closer to the ground, by lifting the lateral column and mets 2&3 slightly?

 

Eric,

a plastic orth is just what Dr Schmidt used to refer to orthotics--”shovels”--it resupinates the rear foot and midfoot at midstance phase of gait.-

I looked at this sentence and realize I did not say what I wanted to say: at heel off not at midstance, surprised no one caught me!

 

Eric-I didn't see/read this post before I responded. So the patient "may" have had a stroke? Whoa...now that changes everything doesn't it? Why didn't you post this originally when you wrote post #770? That's rather disingenuous...don't you think?

An AFO is the proper treatment, no doubt...but why be elusive and/or coy with me? What did you plan to gain by finally admitting that the patient "may" have had a stroke? Did you test for this? Were the sensory tracts effected like the motor? Babinsky? No wonder the patient didn't respond to your "palpations", if, in fact, you actually performed them.

SMH...once again.

 

Jeff,

I'm disappointed that you dropped the ball on responding to some answers I provided you regarding, displacement/fluid movement and pressure. Did you finally get that part or are you still confused or it still doesn't make sense?

Let me know.

 

There was no sensory loss on examination. The information that he may have had a stroke doesn't change the biomechanics at all.

I wasn't beinng coy. I presented all the abnormal findings. You shouldn't jump to conclusions when you aren't sure you have all the information. This guy had a quite normal looking foot and his only problem was frequent inversions sprains. The reason that I presented this was to show how you can explain things easily and completely by understanding moments. When you understand moments you can figure out why this guy has his lateral ankle instability problems. Understanding moments can solve the problems that we have in everyday practice. When I was taught biomechanics (neutral position theory) there was an insufficient understanding of what causes pronation and what causes inversion ankle sprains.

Eric

 

I'm still SMH and your explanation which does little to explain anything. I highlighted the two sentences that exemplify that. No...you did not present all of the abnormal findings in your original post...did you? Try performing Babinski test...or give us clinical findings that elucidate the problem, extent and ramifications.

So let me get this straight...you don't think that a CVA might be a causative factor in peroneal weakness? Please refer back to your post #777 to refresh your memory. You stated that he was fine two years ago. So by your own admission/clinical history, (implying that the patient may have had a CVA), things DID change...didn't they? And NO...the biomechanics are NOT the same after this type of UMN injury. The inability to evert the foot properly would have a serious effect on this man's ability to negotiate irregularities of terrain, (among other things), or even simple walking on flat surfaces. YOU used this example as an anecdotal answer to my second question: how has TST changed the way you examine patients and write Rx's for orthotics?

I guess that wasn't a very good example...was it? Please try again.

 

Of course I thought the stroke caused the peroneal weakness. If the cause of the peroneal weakness was a stab wound to the lateral leg, the biomechanics would still be the same. The deficit is lack of peroneal muscle strength and if everything else is normal then the cause is irrelevant to the treatment that you choose. The guys problem was frequent ankle sprains and the relevant physical findings related to that problem was peroneal muscle weakness. You are welcome to try and explain how the additional information that there was a stroke would change the biomechanics.

Matt, the question comes down to understanding how the ground can cause pronation some of the time and supination other times in the same foot. Sprained ankles happen, sometimes, in feet with pronation related problems. To understand sprained ankles you need to understand how the ground can cause supination. A net supination moment will cause supination. The key word there is net. There will be sources of pronation moment and sources of supination moment. When those are summed together you will get a net moment.

The moment caused by ground reaction force is determined by the relationship between the center of pressure of ground reaction force and the location of the STJ axis. When the center of pressure is medial to the axis the ground will cause a supination moment and when the center of pressure is lateral to the axis the ground will cause a pronation moment. Again, it is the net moment that determines what motion will occur. If the ground is causing a supination moment, but the peroneal muscles are creating a pronation moment, that is larger than the supination from the ground, there will be a net pronation moment and the STJ will pronate.

Steps are variable and the ground is variable. You can step on an uneven piece of ground that will unexpectedly shift the center of pressure more medial to the STJ axis and this will create an unexpectedly high supination moment. Most of the time the ground will cause a pronation moment (for most feet). However, when an unexpected supination moment occurs, to prevent a sprained ankle, the peroneals have to increase the the force produced to increase the pronation moment. So, if you increased the pronation moment from the ground with a lateral wedge you would decrease the chances of the ground causing an unexpected supination moment. An AFO works by applying a pronation moment in response to a supination motion. Any device that would shift pressure, applied to the foot, in the medial arch would tend shift the center of pressure under the foot more medially. This would worsen this particular patients problem.

SMH :bang:

Eric

 

Considering who "thanked you" for this post, I suppose I'll address this reply to all of you, even though I'm replying directly to you, Eric. In your first sentence, you respond that "of course" you recognized that the probable CVA was responsible for the peroneal weakness...even though you never mentioned it until you responded to Jeff Root. So why did you withhold that info initially? It's very important. The lack of strength of the peroneals means he's more inverted at heel strike than he was before. Further, it means he has a lack of eversion strength to overcome closed chain forces, either from above or below. The fact in post #770 you did mention that he only gets to vertical at static stance, means to me that he probably has a barely compensated rear foot varus in the first place. Testing for further eversion at static stance simply requires the patient to rotate his leg inward, and doesn't require peroneal strength.

You go on to state that feet with "pronation problems", (whatever that means...too much?...too little?), also experience ankle sprains. Not often in my practice do I see this...and when I do, it's because of a serious force being applied. Do patients with a rear foot valgus experience inversion type sprains? Nope...hardly ever. (I suggest you look at professional basketball players).

We've all seen the rudimentary drawings of the three basic foot types...but I'll attach them here for reference. If the patient has no eversion available at static stance, they are more prone to inversion type sprains. Further, I've had patients that have told me that they have to be extremely careful even stepping off a curb, for fear of spraining their ankles. They have an uncompensated rear foot varus deformity, almost every single one of them, and the bisection of their calcaneus shows an inverted position at static stance. If you want to refer to this as a "supination moment", fine. But Root Biomechanics will/should predict and address these concerns. There comes a point in time when orthotic therapy will not correct the patient sufficiently and a medializing calcaneal osteotomy will be required. But by inverting the barely or uncompensated rear foot varus patient more through orthotic correction, you allow the patient an opportunity to counteract closed chain forces by allowing further eversion. Simple bisections of the posterior surface of the calcaneus will inform the less experienced practitioner of the foot type.

Forget writing about "moments"...it really doesn't mean much to me, (certainly not in the context you're using it), never has solved any huge problems in our profession, is difficult, if not impossible to measure and is only discussed by the TST crowd. Hope this helps.

 

[Forget writing about "moments"...it really doesn't mean much to me]

Huh??

[, (certainly not in the context you're using it), never has solved any huge problems in our profession, ]

What??

[is difficult, if not impossible to measure]

No.. moments are eminently and reasonably easily measured

[and is only discussed by the TST crowd.]

No.. moments are discussed by biomechanists and movement scientists the world over

[Hope this helps.]

does not help me!

 

How are you measuring moments in your patients?
Jeff

 

Jeff-that question should actually be directed at Kevin Kirby, as he continues to lurk, but not "weighing in" on the topic. I would also like full disclosure from him at some point, ie., how much he's paid to travel worldwide to lecture on TST and/or is his hotel/travel fees paid for.

The push back from M. Angela Evans on my article was above and beyond the pale...which can only lead me to wonder what underlying agenda is being met when she did so. I imagine that this may be the case here as well...after all...the rice bowl is only so big.

 

Reaction force data is collected by a force plate. Segment kinematic data is calculated using digitized coordinate data of body landmarks from images recorded typically with multi camera kinematic systems like Vicon. This allows us to measure segmental velocity. The net joint forces (NJFs) and the net joint moments (NJMs) can then be calculated.

 

The point is, do you do this on each patient you evaluate? And how many clinicians out there do anything even remotely like this? Most don't even use simple tools like a Tekscan system to evaluate their patients. So although moments are important in understanding foot function from a theoretical standpoint, podiatrists don't calculate moments at specific joint when treating patients.

Jeff

 

Jeff,

A “theoretical” moment, is NOT theory. You don't need to measure it in order to treat a pt. You would recognize for example when and where the moment occurs so that you can recognize the inefficiency and error in traditional orthotic technology

 

In addition to the "instability moment", we now have a "theoretical moment"

Dennis, have you just had a bowl of alphabet spaghetti, by any chance?

 

blinda

orig quoted from Jeff Root

So although moments are important in understanding foot function from a theoretical standpoint,

You might want to eat more alphabet soup, and maybe you can learn more English

 

Dennis,

We can observe kinematics when large enough and in some cases, the results of kinetics. Yes, we can design or prescribe orthoses in an effort to increase or decrease STJ and MTJ supination or pronation moments, ankle joint dorsiflexion or plantarflexion moments, etc. but clinically, most clinicians have no way of measuring any resulting change in moments at these joints. Therefore, they use observation and symptom response to evaluate their interventions.

By the way, I have been too busy to keep up with the PA. I know that you and Eric have both asked me questions which I will eventually try to address. I will be at the Western Foot and Ankle Conference for the next five days so I may not have much time for the PA.

Jeff

 

Blinda & kirby

Maybe you're better with “supination moment” because it fits in better with theory and a little science.

 

Jeff

Yes, we can design or prescribe orthoses in an effort to increase or decrease STJ and MTJ supination or pronation moments, ankle joint dorsiflexion or plantarflexion moments,

This is an example of inaccurate modifications. When you do modify to inc/dec etc, your modifications ARE NOT in all 3 planes with equal distribution/balance. It may serve your purpose to inc/dec etc, but because of the inn accuracy of the axis'' of the planes, you either don't get what you want or you get another or different problem in this individuals biomechanics.

 

Dennis,

If you increase the inversion moments at the STJ, you will increase the STJ supination moments at the STJ because of the triplane orientation of the STJ axis. So we don't need equal amounts of force in all three body planes to change the moments at a triplane joint. In all forms of foot orthotic therapy, there is an element of trial and error. In some cases, it may be necessary to modify the device or to prescribe another device based on clinical feedback and treatment results. However, a well trained clinician can get it right the first time, most of the time. He/she also needs to know what, if any logical changes may be necessary after dispensing and evaluating their treatment intervention.

Jeff

 

http://m.youtube.com/watch?v=N9-qNJddcdw

 

Jeff,

because of the triplane orientation of the STJ axis. So we don't need equal amounts of force in all three body planes

I strongly disagree, for “precision” biomechanics, you need equal amounts of force (for proper balance)
at the MTJ 1st. Not the other way around, the way you have it.

When the MTJ is stable, the STJ is then already limited.