Theta Orthotics

I originally posted my question about Theta Orthotics because I couldn’t find any empirical evidence on them. I respect several of the podiatrists here and have appreciated being educated on lower limb biomechanics. As a person in a medical field, but who is not a podiatrist, and, as an oft injured runner for the past 30 years, I’ve been to several podiatrists over the years.

I understand the Root/Weed method as well as a lay person can—I’m attempting to come to grips with Blake’s Inverted Orthotics and Kirby’s Medial Skive as well as other tools that may help me.
Why am I so interested in biomechanics?

Because the podiatrists I’ve seen this past year have not appeared to have been real interested in me. My experiences with them have been frustrating.

I’ve never had an x-ray nor have I been advised to have an MRI or a nerve conduction study. I’ve been palpated and looked at, but—for chronic conditions that shouldn’t suffice—should it?

As I’ve posted previously: I’ve been to a teaching podiatrist, a podiatrist who runs and a podiatrist who previously worked closely with a pioneer in the advancement of orthotics for a decade. Maybe I’ve had decent treatment from these Dr.’s – but it doesn’t appear to me they are following paradigms that I’ve found on this site.

As for Dr. Jarrett—I’ve talked to him on the telephone and found him cordial. Do his orthotics work for me? Truthfully—I’m am afraid to wear them for any length of time because I haven’t found any independent studies that that confirm effectiveness. I don’t feel taken in because I read his website and took a gamble. I didn't understand his theory, but don't understand all foot and ankle biomechanical theories in depth.

As for Rothbart’s? I spent approximately $70 for a product that I’ve been making, for the price of a pair of Spenco Insoles for 30 years.

Thirty years ago when I had a chronic running injury I traveled to Seattle to see Dr. Stanley Newell. His treatment of me and his knowledge of biomechanics were superb. I’m trying not to fly 1500 mile to see another podiatrist that I can trust. But it appears I may have to.

 

I just saw Dr. Newell at the APMA conference in Seattle a few months ago. Just ask him how important Dr. Root’s theories and techniques have been in his life. What concerns me is that as time goes on, those podiatrists who were closest to the source of this information will no long be available and the art of Root theory will be lost. In our quest for science, we often overlook the art of good clinical medicine. There are many Dr. Newell’s out there.

Last post before two days of golf,

Jeff

 

Mr. Root, I made an appoint with him and stayed five days. The poor man had pneumonia.ut came in to see me every day. He viseo taped me, measured me, x-rayed me and thoroughly explained my problems. It was an amazing display of emapathy and podiatry. I am glad to know that he is still living. Thank you, Doug

 

Doug:

Erin Ward, DPM, practices in the Des Moines area and is very knowledgeable about biomechanics, is a runner, plus he is one of the best podiatric biomechanics researchers in our nation now. You may want to look him up.

Since Podiatry Arena is an academic podiatric website, many of us who contribute here teach biomechanics to podiatry students and other podiatrists and, as a result, like discussing the pros and cons of different theories in podiatric biomechanics. Therefore, as a group, we are probably more aware of the different theories in podiatric biomechanics than an average podiatrist would be aware of who has never taught biomechanics.

However, there is a difference between being a brilliant biomechanics teacher and a brilliant clinician. I know of many podiatrists who are great clinically at applying foot biomechanics principles to make excellent foot orthoses for their patients, but would not want them to try and teach biomechanics to students since they simply can't seem to transfer the information effectively to others. On the other hand, I know of some podiatrists who are good teachers but who simply aren't cut out to be in clinical practice since they really aren't necessarily "people friendly".

Good luck with your search for someone who can help you.

 

Thank you Kevin, I will Google him now and see if I can find him. If I can't I'll email you to see if you have his where-a-bouts. Again, thank you.

 

When you see Erin, send him my best regards. He is one of the most knowledgeable biomechanical podiatrists I have ever had the good fortune to meet and spend time with.

 

I could not agree more!

If I may divert this thread for a moment, I think that biomechanics is too broadly used a term, and that many problems result from this.

Most definitions of biomechanics start with "The study of". I think that is accurate. Most of what we bounce about on this forum is just that, the study of human movement, walking, function or whetever.

But think for a second if this is the right terminology to apply to what we do in clinic. How many patients have been treated by reverse kinetic equations, or finite element analyses? Not many.

I think that an effective way to consider what we do is to break it into biomechanics, the study of human locomotion, and musculoskeletal podiatry, the science / are of clinically treating patients.

Of course to effectively treat patients, one needs an understanding of how they work. That is where the study side of things comes in. However I've known people with a very sound theoretical grounding, good biomechanists, who were profoundly unable to assess, treat, and review patients.

Conversely, I've known people who's ability to assess and treat patients was fantastic, in spite of a relatively basic knowledge of biomechanics.

Empathy, experience, communication skills and practical ability are skills which make a good MSK podiatrist, but have little to do with biomechanics.

Rigour, pedantry, attention to detail, knowledge and intelligence, are skills which go towards a good biomechanist, but do not make a good MSK podiatrist.

I think there is a difference between being a brilliant biomechanist and a brilliant clinician (although one often finds people with both skill sets). What I find is that while some (but not all) undergraduates learn some biomechanics, most are horribly lacking in MSK clinical skills. I've known students who could measure, plot, FEA, and talk research with the best, but when they see patients, don't have a clue as to how to even start going about an assessment or diagnosis.

Whenever I do post graduate lecturing, the feedback, consistantly, is that what people hunger for is MSK podiatry training. Pragmatic skills that they can apply to patient care, and ways in which they can utilise their theoretical (biomechanical) knowledge to change what they actually do, day to day, to treat patients. Many have a good knowledge of theory, but no idea what to do with it!

Sounds to me, Doug, as if you've come up against people who may have some biomechanical skill, but a singular paucity of MSK podiatry ability!

Sorry for the digression, its a pet peeve of mine.

 

Thanks Simon, now I'm getting excited!

 

P.S. He's also a nice bloke.

 

Simon, and I hope you realize that I feel that a podiatrist is a person a need to treat me and not an orthopedics M.D. -- you're probably correct.

 

Yeah, but you still haven't told me why the adjacent is half the width of the plate!

 

Doug:

Dr. Ward is located in Perry, Iowa. Hope that's not too far. He would definitely be worth the drive.

Erin Ward, DPM
Central Iowa Foot Clinic
2718 Willis Avenue
Perry, IA 50220

(515) 465-4821

 

Thank you so much Kevin. I've already Googled his address and I'm going to give his office a call Monday. I see where he's written several papers for various journals and I feel good knowing he's a runner as well as a colleague of yours and Mr. Spooner. Again, thank you. Doug

 

Doug:

Here are a bunch of us at the December 2003 Prescription Foot Orthotic Lab Association seminar in Las Vegas. Dr. Ward is on the far left.

Left to right: Erin Ward, Simon Spooner, Craig Payne, Mimi (Craig's wife), Jay Cocheba (and son), Chris Nester, Kevin Kirby.

We need to all do that again sometime!!

 

Brent,

Quoting Hicks is very interesting to me. He was rather clear in his 1954 articles in the Journal of Anatomy about foot mechanics and the interrelationship between segments.

He wrote that the height of the medial arch is directly dependent on the position of the 1st ray. The more plantarflexed....the higher the MLA, and conversely, the more dorsiflexed the 1st ray, the lower the MLA becomes.

How then does adding 20 degrees under the 1st ray supinate the foot? This is simply impossible. You could be excessively inverting it...but supinating it...impossible because you are lowering the MLA profile by dorsiflexing the 1st ray.

Also, when an orthotic of such magnitude is inserted into a shoe, it HAS TO limit the available amount of internal rotation that the hip joint uses to accommodate and attenuate impact loads during walking. What is the effect of a 20-40 degree posted orthotic on hip joint motion? What will be the long term effects of this on hip joint DJD?

Howard

 

Hi Howard,

Interesting point. I think I would agree with this statement in individuals with an everted forefoot to rearfoot relationship. In individuals with an inverted forefoot to rearfoot relationship, if plantarflexing the 1st ray resulted in creating an everted forefoot to rearfoot position of the foot (or cast), then I can also see where this would result in an increased MLA height relative to the plane of the floor. The exception might be in a foot with a highly inverted ff/rf relationship when plantarflexion of the 1st ray reduces the inverted position of the forefoot but does not result in an everted forefoot to rearfoot position. In this scenario, although this may not increase the height of the apex of the arch as compared to the floor, it would still increase the height of the arch when compared to a line (or plane) from the plantar heel contact point to the plantar aspect of the 1st met head.

So what I think is so interesting here, is should we limit our definition arch height to the vertical distance from the floor to the apex of the arch, or do we also measure it from a line that connects the plantar point of the heel to the plantar aspect of the 1st met head. When we use the later method, I would agree that plantarflexing the 1st would always increase the medial arch height. If we just compare the apex of the arch to the floor, then there might be one foot type that is an exception to the rule. All in all, this is a minor point.

In any case, plantarflexing the 1st ray increases the declination angle of the 1st met which in theory should improve the windlass mechanism. That was my concern about Theta orthoses. They appear to be designed or based on the concept of using a varus wedge to support the forefoot. When you cast the foot using impression foam, it usually supinates (i.e. inverts) the forefoot. So these orthoses may have “varus” support in them as a result of casting with impression foam, especially when the impression is done by the patient them self. The valgus forefoot foot type is far more common, which makes me believe that this device seems contra indicated for the majority of foot types.

Nice to see you contribute again.

Jeff

 

Respectfully, I'd take issue with you there jeff. Whilst I cast to a wide range of positions and angular relationships, I more often than not like to have the mid tarsal joint pronated, the first met plantaflexed, to a substantial degree. This is easily acheived in foam.

I think the position of the 1st met / forefoot is down to operator skill / intention, not the medium they use.

 

Robert,

Although it may be possible to fully pronate the mtj when casting with impression foam, this is rarely the result seen by labs. I would be interested in the technique that you use to pronate the mtj when casting with foam.

Thanks,
Jeff

 

Its the 3 point pressure method. Taught me by an orthotist, which may be why its not so well known by pods.

I'll try to do a video and email it too you.

 

Thanks. I can see how you can plantarflex the 1st ray or medial column but how can you dorsiflex the lateral column? In suspension casting, you can feel the end rom of mtj pronation. It is important to point out that that in my experience, supination is the most common casting error I see in suspension casting. So I do agree, operator skill is the most important factor.

Jeff

 

That is the tricky bit. You get a good amount of resistance in the foam, which you can use to pronate the forefoot pretty well from a frontal plane point of view. Dorsiflexing the lateral column is trickier because that foam reaction force acts equally on the base of the 5th met as the head. It's easy to accidentally plantarflex the 5th.

I'm assuming you mean supination of the MTJ, in which case, I'd agree. I see a lot of people who focus on the STJ neutral and let the forefoot go hang (literally).

In foam, I see many more errors. The one thing I've never managed 100% is to get the 5th met dorsiflexed consistantly. Its simple enough to correct out by hand, in clinic, but if this is not done you get a forefoot which is nicely everted, with a nicely plantarflexed 1st met, but a socking great lateral arch from a plantarflexed 5th met. As I say, easy enough to correct out.

The No 2 error is probably failing to get the foot to the base of the box. In POP, one has the bisection of the heel as the base plane indicator. In foam, one has the floor of the box, but that gets awfully tricky if the foot is "floating"

No 3 I'd say is "slicing" the foot in at an oblique angle, rather than straight in.

As you say, a good operator can get what they want from either, a bad one, from neither.

 

By supination we mean plantarflexion + adduction + inversion correct? I should have been clearer I was referencing the PST wedge specifically. In my post above I was pointing out that the PST is shown in a high heeled shoe.

http://www.theta-orthotics.com/html/propulsive_gait_control.html

Wouldn't adding this pad to an already supinated foot supinate it further?

 

clearly the most significant understanding of my basic research...The lateral part of the curve concerns the lateral longitudinal arch, the most medial part of the curve is non-functional.

Originally I did not include the lateral 25 percent as it made logical sence not to. But when the medial protion of the curve was included in the angular measurement, there was no clinical corelation between the angle measured and eit her decreased pronation or clinical resolution of symptoms.

Now it makes perfect sence that the "medial flange" portion of the device in non-functional and should not be included in the measurement. Observation of clinical benefits in thousands of patients over a 20 year period now substanciate a direct relationship between, pronation of the foot and measurment of this angle, as defined by the central 50 percent of the curve created by the orthotic shell/plate.

Until I realised the above no relationship between measurment of the angle and clinical benefits could be established. dr jarrett

 

Yes

but it supinates the foot at a different part of the gait cycle than a traditional rearfoot wedge. I function during late midstance throughout propulsive stage of gait.

 

Incedently that is exactly what others have done including Dr MOrton throughout the patent literature.

 

Brent, if there is contact between the foot and this area of the device, it's functional, believe me it's functional. Do you need me to explain? Hint: divide your frontal plane section into 4 calculate the CoP position in the X direction upon these sections given 10N force acting vertically downward upon each section and a moment arm measured from medial to lateral across the orthosis frontal plane section, then repeat the calculation but discount all but the central portion in your calculation- get the same result? NO. David Smith, Kevin Kirby and I have a paper which should be published in the next edition of JAPMA, you would do well to read it and digest it's messages.

If the "medial flange" portion is none functional- why do you include it in your orthoses? Why not just remove this section from the device?

To be honest Brent, this discussion was vaguely interesting last week when there was noting much else occurring here. Now, it's a bit last week and a thread in which you are trying to promote your more than flawed theories. Unless you can come up with something good, I'm going to loose interest rapidly. For example, you were saying how the 3D surface geometry can be defined by a frontal plane section at the highest point of the arch and a sagittal plane section at this point. As I recall I said this was nonsense- care to elaborate, before I post models disproving this conjecture?

 

Damn. Gonna have to send all those ucbls back.

Simon said it Brent. I'll say it simpler.

Does the medial flange touch the foot? Clearly yes. In fact this is where I often see blisters.

Therefore

does the medial flange exert force on the foot? Yes. See above.

Therefore

it sort of IS functional!

Unless of course your rationale is that the medial flange does not stop the arch dropping because it's up the side of the foot! (that's a joke btw).

 

You sir, are just throwing petrol on the fire which is occurring upon a sinking ship in a tempest. I like it though. Let it burn, it's keeping me warm:drinks

 

I'm just attempting to point out the irony of it all.

 

I know!:drinks Jeez, can you imagine it, American's giving the English lessons on sarcastic and ironic humour... I mean, the irony of it? I'm joking Jeff... You the man, as they say in North America.

 

Hi Robert

Could you post the video you sent to Jeff on here

thanks

Robin

 

Nothing like a good orthosis debate amongst arch enemies!

 

What's that got to do with irony? You're from the Isle of man, for pitty's sake...
p.S. I told you it was getting boring, Brent.

 

simon

actually the medial flange is NOT included in my orthotics...once the point of max height or angle is reached my design levels off toward the medial portion of the shoe. It serves only as a spacer to position the appropriate portion of the wedge
against the foot...

plot a point in the sagital plane, beginning were the varus wedge begins near the end of the heel, see how it rises to a maximum verticle at the tnj and then terminates back on the horizontal axis just before the weight bearing metatarsals...if you recal from algebra this defines a parabola and every point is defined by the x and y intercepts and the maximaum value of y...

truth is your theories are flawed...truth is I have tested my theories on thousands of patients over the last 20+ years clinically...truth, I have not tried to promote my theories to you as I know you are either incapable or unwilling to understand them...truth is you have tried unsuccessfully to disprove my theories...truth is lyou bore me...brent

 

Often a sparring partner, never an enemy.

 

Arch enemies, not you! I was referring to the conflicting theories of the importance of arch support, not their proponents or opponents personally.

 

It isn't necessarily a parabola though, is it? Moreover, does an X and Y in isolation define a complex 3D surface?

Which theories are they? The theory that if a section of the orthosis is in contact with the foot it will have an influence on the net reaction force vector produced by the orthosis upon the foot? Tell me how this is flawed?

Truth is, you haven't got any worthwhile data to support your theories, or you would be publishing it in JAPMA to try to win yourself another Stickle. The fact is, you haven't provided any counter to any of the arguments put to you; I "bore you" because I have been among those to expose you for what you are. Yeah, bye, Brent. Prof Kirby called it.

 

Put a pressure sensing insole on it, if the foot touches it, it's having an influence. End of story.

The burden of proof is upon you: provide evidence to support you theories.

http://www.youtube.com/watch?v=wDWEs8RJ0v0

 

Brent would you agree or disagree with the statement that the foot reaches maximum pronation at the end of midstance, and the that subtalar joint supinates the foot from midstance through toe-off via the windlass to act as a rigid lever during propulsion (toe-off)?