Theta Orthotics

I don't have that info available, but I can tell you that a 200 lb man will compress the device no more than 2-4 percent with a complete elastic return to the original configuration...brent

 

Can we???

Yay!!:santa:

I love that concept. Totally blew me away that did. One of my top ten lightbulb moments!

 

Duval,
a relationship between orthotic angulation and change in function can be observed of course, as it has been in every patent and clinical reference to orthotics, but exact quantification is necessary to understand the process and control the important angular variables sufficient to qualify as scientific process.

Dr Glaser is correct that more angulation is better, but because he has not yet quantified the angular design of his orthoics, he can not insure, predict, or control what he does. Qualitative interpertation of orthotic design as it relates to function has been done by everyone, but quantitative evaluation has been don only by my self with both rf and ff wedging and only by Dr rothbart as it relates to ff wedging. Until ED quantifies his orthotics his argument will allways appear empty and definitely incomplete. brent

 

In which peer reviewed journals can I find your published work on this to read it? I read some of your statements on the you website and frankly they show to me a naive understanding of foot orthosis and their effects on the kinematics and kinematics of the lower extremity. I understand the concepts perfectly, you have added 40 degree rearfoot posts and 20 degree forefoot posts to foot orthosis. And this you perceive is optimal because.........?

The load/deformation characteristics are important because when it deforms under load the deformation will not be evenly distributed across the orthosis, and your magic angulation will no longer exist. Now your 200lb man might be exerting 500lbs upon the orthotic when he's running, how does it deform under loading in these circumstances? You have no idea- right?

 

robert,

Have to admit you guys have fatigued me, big balls or not...you will either have to figure out the rest on your own, or wait until I feel like biomechanics is fun again...brent...thanks for a discussion beyond name calling, I honestly did not expect that to happen from your group, even if the primary motivation is to discredit rather than learn...

 

Once again, we have an advocate of higher arched orthosis using a softer, more compliant material. Therefore the higher the arch of the shell, the less rigid the shell material must be. Why? Because the arch will not tolerate being supported in this high position because it is normal for the arch to lower with the necessary and normal motion of closed chain pronation of the foot during gait. So we are back to the unanswered question of how much of a change in position or forces is necessary eliminate symptoms.

Merton Root often said and also wrote that we could eliminate pathology in many individuals by simply preventing end range stj pronation during the propulsive phase of gait because that is when the foot is subject to the greatest force and the greatest rotational moments because of the angular relationship of osseous structure the foot.

 

The deformation is insignificant either way, I would be happy to provide you with a sample and you can perform all the functional tests you want. I could probably explain it better verbally and with props, but it is just a little more complicated than just adding a rearfoot post. Based on consultation with members of the US research community (specifically Dr Donald Green) whom I respect, I have not published at this time, as the podiatric comunity is most probably not ready to accept my concepts. Your groups initial responce to my research certainly substanciates this belief. brent

 

your comments force me to remain engaged fatigued or not...It is not soft and not compressable, go back to www.pcopco.com.orthotics.html, I specifically state that the anle of correction must be maintained furing function (read it agin trying to understand not discredit)

YOu are absolutely correct about roots understanding about propulsive stage of gait, which is why a ff wedge is necessary but obviously absent in most all orthotics. Interistinbg you can dismiss Dr Rothbarts research yet understand the importance of propulsive stage contrl...a material that will flex but not compress is necessary when a ff wedge is employed...brent

 

The deformation is highly significant for a number of reasons which you clearly have not grasped. So, Don Green, who I also know on a personal level and have found to be very switched on and well read, did not like your propositions? So what? There is only one way that you will test the water and that is to publish your work. That way you will reach a far wider audience and will really know the perception of your peers to your work. Who knows, if it's good enough you may win another Stickle. I 'd be happy to look over your data and give an honest appraisal.

Now, I'm still interested in coupling. I'm intrigued as to why you think that coupling between the foot and the shank occurs with a 1:1 ratio and why you think that a 1:1 coupling ratio exists between the foot and the orthotic when every study that has ever been performed to my knowledge demonstrates that this is not true... Please explain. Perhaps if you have data to support this contention of yours now would be a good time to publish it?

I tell you what, rather than sending a physical sample send me a CAD file and the physical data for your material instead and I'll pop through an FEA run for you- gratis.

 

Before I realized the importance of the ff wedge, my original work that defined Theta, was done with Roadure orthotics only...brent

 

Brent, let me ask you one straight-forward question:

How do foot orthoses work?

This question is key to any further discussion here.

 

Simon,
Thanks for your offer I may take you up on it at some time...I have attempted serveral times in this discussion to explain the relationship betwen both rf wedging and rotation of the tibial segment, and ff wedging and rotation of the tibial segment,apparently and not surpiseingly unsuccessfully...I think I woud be best to try again with a different format...I's sorry...

Even though I have experienced lack of acceptance from virtually all of my medical collegues, with reguard to my biomechnaical research, I understand why, and don't feel compelled to try and force it down YOUR throats at the moment. For now I can continue my research as long as patients fail to get the help they need from traditioanl sources. Brent

 

Simon,

Best question yet...all functional orthoses change the angle of the support plane and therefore compensate for frontal plane angular pathology in the leg.

In fact I define a functional orthotic as one that changes the angle of support as opposed to an accomodative orthotic which attemts to redistribute verticle forces with depressions and ridges...by my deffinition most all prescription and OTC orthoics are functional orthoses...sorry if that offend some...brent

 

Simon,
If you are refering to ED, you are right on target...he suggests that he mysically matches specific durometers of polypropelyne (type) plastic to the weight of the patient. That is in my opinion a bunch of bunk as any compression of the foot control device during function will deminish the benefits of the treatment...brent

 

Brent, here is how I see it, I have read a lot of published work recently on coupling between the forefoot, rearfoot and leg segments (everything I can find). Nothing I have read has suggested to me that a 1:1 ratio exists in the coupling of these segments, the exception being the brief periods of in-phase coupling of the forefoot on the rearfoot in association with pathology reported by Ryan Chang. I've certainly never seen a study in which the angle of posting of the orthotic was linked in a 1:1 fashion with the rearfoot position and motion. However, if we extrapolate from Chang's work, 1:1 motion, in the foot at least, may not be a good thing.

I'm a scientist, I worked long and hard to be awarded the title of Dr for my PhD work. Now, if you want me to come around to you're way of thinking you are going to have to provide me with a little more than "it's like that because that's how it works". It may work in advertising to the lay-public, but it won't work with me. So you saying that you have said it to other people and they didn't get it doesn't work for me either, I've said many things to many students and the look in their eyes told me they didn't get it either, so humour me.... lets see if I get it? You are not forcing it down my throat, I am willing and asking you for it.

But first answer the key question:

How do foot orthoses work?

 

C'mon Brent, thats not answering my question and you know it! You dissappoint me.

The study, as I say, shows no external rotation in the leg with 15 degrees of whole foot inversion. Forefoot midfoot and rearfoot. This is directly contrary to what you claim. Duval is both wrong and irrelevant in this post!

And then, exit stage left Dr Jarrett. Oddly.

The reason you cannot gain acceptance for your theories, Brent, is not that we don't understand them. It is that you present no evidence, that your opinions are backed by nothing more than "I believe" and that they are wildly inconsistant with what is known. We get what you believe, we just don't share it. We understand, but you offer nothing beyond your subjective opinion. And, to be blunt, you have a vested interest in your opinion.

You keep talking about your "research". Treating patients by mail order is not research. Here is an idea for research.

Send a pair of your devices to an independant researcher and have the kinematic effect of them tested. Use one of the existing studies as a model for methodology if you like, then no one can accuse you of prejudicing the design. If you can show that a 40 degree MLA and 20 degree forefoot consistantly results in a 20 degree external rotation of the leg, then we have something to discuss. THAT is research. Giving patients insoles and telling us they got better is not.

Do you, in all seriousness, expect your colleagues to simply believe that a 40 degree MLA is optimal, simply because you say so? Would you believe that 30 degrees was optimal if I said so? Of course not, and you'd be right not to.

Your claim, that your way makes sense, and is best, is one made by dr rothbart, Dr Glaser, Dr shavelson, and others too numerous to count. You don't beleive that their claim of "MY way is best" is true. Why would you think that we should believe you and not them? Why would you ask us to do something you will not, that is, accept an unsubstantiated statement of what is optimal from someone with a clear profit motive for making their case?

Bye then Brent. It was fun for a while, but yet again when the going gets tough, the tough get FAR to busy to keep answering questions.

 

Brent,

I did look at your website before I replied. In your estimation, what percentage of the general patient population would you say has an inverted ff to rf relationship and needs a varus ff post?

Thanks,
Jeff

p.s. As a lousy speller and a probable dyslexic myself, it's always nice to have others on board! Thank god (or Bill Gates?) for spell check! Or sohuld I say, tahnk god fro spel chcek!

 

The incredible total of nearly 100 postings from multiple posters in only 24 hours on this thread regarding another orthotic product makes me think of one thing.........

 

Reproduction? Now, be nice Kevin! Actually, these discussions although painful, are sometime fruitful just because we are not preaching to the choir.

 

Moreover, a 20 degree forefoot varus post? Lets look at that trigonometry again, lets say the width of our shell at the forefoot is 8.5 cm (not random, I just measured a pair of orthotics made for my size 11.5 UK shoes) and we run the post full lengh across the shell, then opp = tan 20 x 8.5= a forefoot post which is 3cm high on the medial side of the device in the case of a forefoot varus post. That'll get the windlass at your 1st MTPJ working better- not :butcher:

 

Simon I appreciate your sincere effort to understand.

It should be obvious that wedging under the first metatarsal has a direct supinatory effect on the foot, just as elevating any one of the three legs of a tripod has a direct relationship to the horizontal platform at the top of the tripod.
Of course that theory is shared by Dr Rothbart so even if logical shoe be discredited. NOT

The function of the rf wedge positioned directly under the TNJ is a little more complicated. Corrections up to 20 degrees may supinate the STJ with minimal effect on external rotation of the tibial segment, depending on the position of the stj and tibia before wedging. This relates to the anatomical angulation of this part of the foot as described by Hicks.

Above 20 degrees of varus wedging there is a 1 to one relationship between supination of the STJ and external rotation of the tibial segment.

Because Dr. Glaser frequently achieves angular corrections as much as 25-27 degrees he believes that he sees a more pronounced and consistent effect on rotation of the tibia and subsequently body posture, WHICH HE does.

The reason many studies fail to document a one to one relationship between STJ and tibial rotation, is because rarely do they provide more than 20 degrees of varus angular correction in the rf or mla. This direct relationship can be doumented in a maximally pronated foot, somewhat in a flexible forefoot valgus foot type,but not in a cavo varus foot that is already more supinated than the varus wedge.

When varus corrections above 20 degrees are employed, not done with traditional prescription orthotics, at least all of the ones I have measeured with may Theta technique, the one to one relationship can be observed.

Not sure if that helps you understand any better or not but I tried my best at your insistence...brent

 

No Jeff, we are signing to the blind, preaching to the deaf and encouraging the dumb!:drinks

 

Damn. Pinot on the keyboard again!

 

Hi Brent
Sorry but I am a little confused. Could you point me in the right direction for your papers published throughout the 20 years of your research.
I've had no luck on Google scholar, Science Direct etc

Thanks in anticipation

Deborah

 

Unfortunately not. It's not that simple. A wedge under the 1st metatarsal will cause an increase in dorsiflexion moment (it may or may not change the 1st metatarsal position) at the 1st metatarsal-medial cuneiform joint, how this acts at the midtarsal joint will be dependent on the other forces acting upon the forefoot segment versus how the forces are acting upon the rearfoot segment, these moments in turn will also provide a net moment acting about the subtalar joint axis, this may be a net pronation moment or a net supination moment, the way in which this couples with tibila motion will be dependent upon a number of factors, not least whether the subject is running or walking. Brent, I haven't gone to the trouble to post the links I did for the fun of it, please read what the data tells us. The tripod view of the foot is somewhat dated, going back to the early 1900's, while it is occasionally useful as a simplistic model to explain concepts to patients, in research terms it is irrelevant now.

Who says? How have you measured this coupling data and in how many subjects?

You have data to support this statement? I doubt it.

This may or may not be true, it is a hypothesis without data to either disprove or prove it as far as I am aware. Like I said, if you have data which supports this or disproves it, it deserves to be published. Once again, how did you measure coupling though- dynamic function or static stance?

Yeah, we need to nail down exactly where and how you are measuring that angle within the orthotic shell, the picture on your website showed an angulation across the rearfoot post area in the frontal plane.

Brent, rather than seeing people here as enemies, try looking upon us as advocates who are trying to help you improve your theories and knowledge base. You won a Stickle gold award some years ago. When you submitted your manuscript you got feedback from the reviewers. I don't know, they may have said: :this is a great paper" straight away, and: "you don't need to change anything", but my experience of publication is that the reviewer offers critical advice on things to change which ultimately improve the quality of the paper.

 

Simon,

taking in consideration your hat an moustache, you are beginning to impress me...

the formula is tan (theta) times side adj. = side opp.

The CRITICLE part of my measurment is defined at www.pcopco.com/orthotics.com and without explaining why right now, it is half of the 85 mm measurment., took me three years to figure that one out.

So take the 8.5 cm or 85 mm as I use, devide it by half (go back and review www.pcopco.com/orthotics.html ) multiply that by the tan of 20.
Therefore .3640 times 42.5 mm and you get 15.47 mm. This is the vertical distance in mm from the horizontal plane to the spot on the superior surface of the orthotic (that I define in my deffinition at www.pcopco.com/orthotics.html) for a 20 degree angle.

This is half of what you got because you used the same side adj that I tried to use unsuccessfully for the first 3 years, and could not relate function to orthotic design. The measurment of the full width includes the non-functional ( suspected but not originally understood by me)medial flange. and the part of the curve associated with the lateral longitudinal arch. Only the central 50 percent (as diagramed and described at the above link) was ultimately identified as the functional part of the hyperbolic curve created by the plantar arch.

My Clinical observations maintain that if you increase angular correction 5 degrees to 19 mm you will almost double the clinical benefits of treatment. So what are you waiting for , you don't have to belive, just understand to try and see for yourself.

Importantly if you plot the vertical distance for angles between 10 and 40 you will see the logrithmic relationship that is ultimately responsible for such pronounced changes in force vectors related to the 400 percent increase I claim at my site. (Take that to your UK attorney Robert).

Never thought we would get that far in this discussion...nice...brent

 

Simon,
Not that I see you as enimies just, close minded bum bags, that only wanted to discredit my research. I am starting to see things a little diferently thanks mostly to Robert and now you.

Actually no revisions were asked or required of my Gold Stickle paper, for what I thought was insignificant research, compared to what I have done for the last 30 years. Begining to believe that the more important the research is the more difficult for it to be accepted. I have been content for a long time to continue to collect documentation awaiting the right time. brent

 

Brent, I think I have seen the light, and I believe you - it makes sense now!

Not really, I still think you are talking sh!t.

But I had to get your attention you understand. You appeared to have forgotten to answer my simple question. You must've forgotten as you wouldn't ignore me would you... that would be rude.

A refresher:

So, third time of asking: How would you treat a peroneal tendinopathy with a Theta orthotic?

 

Deb,

The first time I submitted papers to Japma about 10 years ago, I was not as clear as I am today (right) and admitedly my papers were not so good...obviously they were denied and I went back to research for another 10 years...About 2 years ago I spent the winter months writing this article www.pcopco.com/orthoics.html

Even though it was only a review of the patent literature, with interpertation of my own theories, I was pleased with how succient and organized my thoughts were experssed on paper. Although I suspected that It would probably not be accepted I felt compelled to ask Dr Green to review it for me. I antisipated his response but determined that our profession was not quite ready for my theories after he basically refused to discuss any element of the paper with me.

Answer: None of this research has ever been published...brent

 

sorry that link is www.pcopco.com/orthotics.html

 

:sinking::craig:

 

yeah, I know, that's what I wrote last night and tonight.

Brent, I'm afraid that if you want me to stick with you as an advocate, you are going to have to explain, right now, why it half the length of the adjacent? I don't know why you are putting lots of links into reply's for your website that don't actually relate to the answer to this point, but I can guess. The problem is that before too long, when people search for your product this is what will come up on top, regardless of your efforts.

Yep, I can do basic multiplication, I don't know why you have halved the length of the adjacent side. I thought you were using trigonometrical functions? Can you show me the trigonometrical function in which tan theta = opp / 0.5 adj ? Please tell me you are not using a longitudinal bisection of the foot as you inversion/ eversion axis and dividing by half on this basis... Cause if you are, its crap.

No, take me to your data. The vertical distance of what? Plotted against the log of what? Force vectors measured how? 400% increase in what? You're not blinding me with science I'm afraid, Brent. Show me your data.

 

Ian,
sorry when I read your question last night (morning) I wanted to get to it because peroneal function is as significant as any other muscle change associated with biomechanical control of the foot, but when I tried to find it this morning I could not, this thread if somewhat volumanous, I assure you no deliberate attempt to ignore...

This is almost as complicated as stj supination and internal rotation...

First off I admit that I am not sure what PB actually does except perhaps to be used as a new lateral ankle ligament...PL however I understand to be a significant player in foot function. Because 1st met plantar flexion is directly associated with supination of the foot it comes in to play weather you attempt to control function with just a traditional rf wedge or both rf and ff wedges combined.

Only the last 10 years have I understood the dynamics of this muscle.
Basically when Theta is increased above 20 degrees the first met must pf to come down to the ground. pl strain and discomfort is common as the foot adjusts to the change in function. when rf correctio above 20 degrees is equal to added ff wedge, the pl does not need to adjust as the ground is brought up to the weight bearing plantar 1st met.

So clinically when rf corretion is below 20 degrees minimal reduction in pl symptoms are observed... when correction is above 20 degrees symptoms generally increase at first then decrease over time.

If both rf correction and ff corection is used symptoms usually decrease from the get go...

If only ff correction is used and immediate decrease in symptoms should be expected...brent

 

Thanks for your answer Brent. One more question if I may?

How would you treat a Tibialis Posterior tendinopathy with a Theta orthotic?

Thanks in advance

Ian

 

Brent,

Looking at the drawings below from your website (http://www.pcopco.com/orthotics.html), it appears to me that you are attempting to mathematically "define" that which is automatically captured by and represented in the physical cast of the patient's foot. So unless you are using a pre-made device or mold, then I don't see what is gained by measuring the angle of the convex, frontal plane curve of the arch of the foot. In other words, when we use direct capture of the foot (a physical object) and make a device from a mold of that foot, we don't necessarily need to know the angle of the resulting device because it is intrinsic to the device. Am I missing something and if so, what?

Jeff

 

Jeff, like said some posts back we need to know where this 40 degree angle is being measured. If it is where the picture you attached is suggesting, I'm guessing stacks of devices, prefab and custom can boast similar angles if not greater. I've been assuming it was a frontal plane rearfoot posting angle at the centre of the heel cup. Now, given that diagram, at what point is the orthotic plane 40 degrees? Why, arbitrarily divide it into 4 units and not 14? Moreover where is the centre of pressure on that section of orthoses, what is the direction and magnitude of the force vector in relation the resultant axes. This is the kind of sketch I've posted here numerous times to demonstrate various points. What's the co-efficient of friction of that surface? Is the foot sliding up the incline, or down it or static? And this is a new invention because.......

Jeez, I could take any CAD or physical model, segment it and measure the angles far more accurately merely by increasing the number of nodes. The point is you need to look at the discreet force at every point, take moments in both the X and Y directions, taking account of the discreet 3d angulation of the interface plane at each point to calculate the net orthotic reaction force vector and then know the axial positions in relation to this vector. If it was easy as sectioning a model and dividing it into 4 and loosely measuring the angulation of part of it in one plane, my life would be easy and I'd be playing on the swings with Grace instead of wasting my time here. Goodnight.

 

Ian,

you will see a decrease in symptoms almost immediately with any rf, ff, or combination rf and ff correction. treatment is best achieved with comb. rf and ff correction, resolution of symptoms improves as the correction, theta, increases. I generall find the highest level of correction they will accept to begin with then increase both rf and ff correction gradually until ALL symptoms are resolved.

This means that any orthotic you want to use will helps some, but treatment with combined rf and ff is most effective and natural. I realize I have not yet discussed why that is...brent

 

again, please refer back to www.pcopco.com/orthotics.html

It specifies that the rf angle of measurment is at the apex of the mla or just under the tnj... you are correct that you could stack both prefab and custom devices to achieve more correction...many of my patients first read my ssite and understand exactly what you just said. Many add prefabs to the custom orthotics they already wear to prove my point before calling and ordering from me...it is tough to get much mre than 27 degrees with this techniques and it becomes a bit bulky etc.

I often teach a patient how to add ff correction to their existing device as well...I realize that current theory does not usually utalize the ff correction but as one of you quoted root as saying, propulsive stage function is criticle in overall foot control...brent

 

So this is what I have so far,

When I asked how you would treat a peroneal tendinopathy you said:

And when I asked how you would treat a Tibialis Posterior tendinopathy you said:

So... if I have this right (and please correct me if I have not) is your treatment for these two pathologies essentially the same? That is, it will be a varus post either at the forefoot, rearfoot or both?

Thanks again in advance for your time

 

right but even the mold has to be quantified to begin with. but once done you know what it will be every time...I am sure most of you know about original DR Alzners pre fab orthos. Often a patient would come to my office with a bag of orthoics. I would ask them which one they ended up using and virtually all would tell me the alzners because it always measured 23 degrees...at least 3 degrees higher than any prescription orthotic in their bag...

btw I was only into my research a few years before I realized that generic orthotics could be fabricated and work as well as orthotics customised to the cast.
when a pt who wore a 40 degree rf roadure broke one, I made another from her sisters cast and sent it to her in NYC within 3 days she could not tell the difference from the one made off her own foot. AS you may know when arch length and width are known the contours of the plantar foot can be determined with formulas that ultimately create the required contours...unfortunate news for those who think custom fit orthoics are the only way to go...brent