Podiatry Today:
EXCLUSIVE INTERVIEW
Back to the Root - Q&A
Mention podiatric biomechanics and the name Merton Root immediately comes to mind. Indeed, Normal and Abnormal Function of the Foot, which Dr. Root co-authored with William Orien and John Weed, is the bible of foot orthopedics. Yet for the past several years, little has been heard from this legendary figure, whose painstaking research into classification, pathology, and treatment will influence podiatrists for generations to come. From his California home, Dr. Root granted an exclusive telephone interview to executive editor Judith A. Rubenstein and Board of Editorial Consultants chairman Harold Rubenstein, D.P.M. An edited transcript follows.
What have you been doing for the past several years?
I don't maintain an office. I have rheumatoid arthritis, and I had to leave practice more than twelve years ago. But we have a laboratory, and occasionally conduct seminars for some of our customers. I also do some consulution and teaching.
Admittedly, foot orthopedics is a complex subject. But some people have suggested that you have made it more complicated than it really is. Would you agree?
I have just barely scratched the surface. What I don't know could fill many books.
Are you planning to publish another book?
Well, I haven't written anything on the structural abnormalities that I've found over the years. There are about twenty-five or thirty of them that need to be described in detail, as well as the treatment and prescription for them. The initial volume on examination of the foot needs to be upgraded and expanded. We knew that at the time we wrote it, but we didn't want to scare people off either.
Did you ever imagine the extensive impact your research would have on practitioners around the world?
In the 1960s I began to lecture nationwide - every two weeks I traveled to a different city for three days. During my lectures, men would break down and cry because my lecture shook them up. They were totally frustrated that they were so far behind - that this material had been out there and they'd gone to school and hadn't received it. I couldn't believe the impact I had on people. Yet rather than being excited about receiving something new, it created the opposite effect - total frustration and anger and other emotions that amazed me.
Nevertheless, you are highly regarded.
I don't know why. Perhaps it's because I'm very outspoken.
What was the extent of knowledge about foot orthopedics before you began lecturing and publishing?
Let me go back a little further than that. What we learned about orthopedics when I went to school was purely empirical. People would do things, obtain results, and it became a methodology - just because something good happened. Unfortunately, there was no clearly defined scientific terminology to describe position, motion, or anything of that nature. There were no clear-cut methods to determine foot type. ln fact, there was no real classification of feet. As a result, the primary classifications that doctors used were first, second, and third degree weak foot. The treatment was pretty much the same - it didn't make any difference what you were treating. Unfortunately since practitioners didn't understand the etiology that caused the symptoms, patients didn't respond well to treatment.
So you found your niche in the profession?
I initially went into podiatry because I was interested in research.
Merton Root at California College of Chiropody (now California School of Podiatric Medicine) in San Francisco, graduating in 1952.
Where did you study?
I graduated from the California College in 1952. In those days school was quite easy, but people didn't like the ideas of research or investigation. I can remember telling my orthopedics professor, Dr. Norman Burgeq who was also the school's dean, that I had so much time on my hands I was playing a lot of bridge. I'd rather spend that time working on some research project. He told me I was better off playing bridge.
That's how you got into biomechanics?
I didn't realize it was biomechanics. Starting in my freshman year, I became very interested in the physiology of the neurological system. I ran across the concept of proprioception. This was never taught in podiatry schools, but it really impressed me as a very important area of physiology that should be taught.
Why is proprioception so important?
It is critical to the mechanics of the body. As I asked questions about the cause of different symptoms, I began to realize that nobody understood what caused a corn or a callous or a bunion - or much of anything that we were treating. It was all symptomatic treatment. We had no knowledge of function. When I left school, I began to pursue function, but I couldn't understand function until I understood foot morphology - the structure of the foot. I recalled from my reading in botany that Linnaeus classified plants according to their morphology, their shape and structure. I decided that's where I would start.
To classify feet?
Well, I began to try to classify feet. But I found as they move from one position to another, there is no consistency in the structural relationship from one part to another. So I had to find some reference point at which I could put the foot so that I could compare one foot to another. I worked on the subtalar joint for about a year measuring it, trying to understand it. I had been pondering the variances that I was finding in my measurements. One morning in 1954, just by luck I guess, I was standing in the shower without any thought about the foot and all of a sudden the concept of the neutral subtalar joint position flashed into my mind. I could hardly wait to get to the office to substantiate it. That's what turned out to be the key to my being able to contribute to podiatry.
Until that time were there any references to this in the orthopedic literature?
No.
Subtalar Joint Excursion
Were you doing these measurements on your patients?
Yes, but we had no consistent way of measuring because until I found the neutral position of the subtalar joint, we had no consistent reference point. So measurements varied.
What happened once you esablished the neutral point?
Then I was able to measure the entire lower extremity from the hip down.
Is there a verified normal range of motion in degrees to the midtarsal joints?
No. I don't believe in normal range of motion. I believe that if an individual has adequate range of motion for the functions that individual is using the parts for, that's the normal range of motion. But to say that the average in a hundred people is 20°, therefore that's a normal range of motion - this is poppycock.
So you evaluate case by case?
Yes. An athlete (who needs a greater range of motion) doesn't have a normal range of motion if he can't perform the functions he needs to perform as an athlete. For example, one of our laboratory employees is a long-disance runner. She has an internal femoral torsion at the hip which wouldn't bother someone who was just walking and using that extremity for every-day work. But when she was running up to ten miles a day, she developed stress fractures at the hip because it was exceeding its range of motion and actually jamming against the acetabulum. She had an adequate range of motion for walking and functioning, but for her athletic activity, she didn't, and she paid the price.
How did the term "functional orthosis" evolve?
That's my term. To my knowledge, the only functional orthosis that we had prior to what I came up with is the Whitman orthosis. It was based on the principle that if you started to pronate the foot, the orthosis would gouge the navicular area of the foot, be uncomforable and when the person used his muscles he would tend to resupinate the foot. The Whitman orthosis was used to treat children's feet. Unfortunately, it was based on some inadequate scientific concepts and wasn't too successful, although it was still in use when I first began to practice.
Have you of your colleagues been able to document systemic effects related to the use of functional orthosis?
Yes, particularly postural problems. Unfortunately, I've never had the time or opportunity to write about it. Maybe I had the opportunity, but I've been too lazy. We've been able to correlate symptomatic syndromes with various types of foot abnormalities. For insance, rear foot varus will produce a complex in which the lateral thigh muscles become tender and the erector spinatus muscle on the side opposite the foot deformity goes into spasm. That spasm then carries on up the spine and will produce a scalenus anticus syndrome on the opposite side of the trunk, on the same side as the foot deformity. We've found symptomatic and other types of correlations with functional limb shortages and structural shorages. With the loss of shock absorption you have a very serious spasm associated with the lumbar spine. Each one of these particular entities has its own peculiar symptomatic pattern that develops. We've been able to treat these people and relieve the spasm or the problem that was present. But if we took the orthosis away, the problem would return. Put the orthosis back on the patient and the problem disappeared. We could repeat this for three times in a row and reconfirm each time that there was a definite cause and effect relationship.
Undoubtedly, many podiatrists have cases like that, but perhaps they are hesitant to acknowledge the cause of their successful treatment because they can't document it.
But they very definitely can. I've treated a nineteen-year-old girl with a head tilt due to a functional limb shortage. In fact, I straightened up the head tilt so rapidly that she developed migraine headaches, so we had to slow down. Postural problems can indeed be treated. The key is that people have made statements in the past and haven't confirmed them. It's a very simple matter. For instance, orthoses can sometimes cause back pain. I would see two to three cases each year where for some unexplained reason - and I still can't explain it - people would develop acute low back pain. I would take the orthosis away, the back pain would go away, put it back on and it would return. Then I would take the post off and allow greater range of motion. One or two of the patients could tolerate the orthosis without any pain. But others continued to have back pain, so we had to remove the orthosis. There was no way to treat them.
Controversy still rages over whether or not children should be treated for biomechanical pathology, such as a compensated calcaneal varus that's excessive for their age. What is your recommendation?
Primarily the battle continues out of ignorance. If you are looking at flat feet and that is your classification or determination for whether or not a child should be treated, I can see a problem. From birth until the adult contour develops at approximately seven to eight years of age, a child normally has flat feet. In fact, if a child doesn't have flat feet, something is wrong with the foot. So, the child's foot, which is more fleshy, should be low arched and somewhat flat. But many podiatrists end up treating such truly normal feet just because they are relatively flat. The same thing is true of the pediatrician who looks at flat feet and says: "Don't worry about it, the child will outgrow it." And that is true - if it is a normal foot that is flat.
What it really comes down to is: does the doctor have the capability of differentiating whether a flat foot is normal or abnormal? Can he determine what that abnormality is? Is he capable of treating it with orthoses? If he is, then he should treat it because these abnormal forces that cause the foot to function abnormally cause a retention of juvenile ontogeny. Basically, if you look at a subluxed adult foot, you are observing a retention of the foot's shape from about the time the child first began to walk. A foot can sublux beyond that point, for example a compensated equinus, and actually become worse than the juvenile position. Nevertheless, most subluxed feet are just the retention of that very weak juvenile position, a foot that is not capable of normal bipedal locomotion.
Are you in favor of treating truly abnormal biomechanical deformities in children?
Very definitely. By resisting those abnormal forces, you allow normal ontogeny to develop, leading to a more sound structural foot by the time the child is an adult.
In my experience, the person who pronates abnormally will develop symptoms, but they are usually very insignificant symptoms and seldom painful. A good example of that is a compensated rear foot varus where the foot pronates to the vertical and is the only problem in the lower extremity. That person will see a podiatrist about once a year to have the callous pared off the sole of the foot. Sometimes the bunion will develop to a point where it will be slightly tender. But the person usually doesn't want - or need - any major treatment. However, put that same amount of pronation into a foot that is subluxed, a foot that has a juvenile ontogeny. Now because of the structural instability of the foot itself, compounded by the instability caused by pronation and the ensuing traumatic shearing forces, the symptomatic changes are probably ten times as bad. That becomes a very acute foot problem.
Charcot Foot
I have seen normal adult feet that suddenly collapse, sublux and become totally flat, as, for example, a Charcot's foot. That can happen. But most of what we see is merely a retention of juvenile ontogeny.
Let me qualify what I've just said because this concept has never been confirmed, and the ten percent figure I've used may be way off. A subluxed foot that pronates abnormally is much more symptomatic than a non-subluxed foot that pronates abnormally.
Here is a Rohadur orthotic on pitcher Gaylord Perry. Also next to Merton Root is Jack Haitt and a trainer stands between.
Is there any documentation to dempylene, graphite and rohadur?
We've worked with those in our laboratory. The polypropylene will change shape just by its own weight. For functional control it is too flexible. It has too much molecular flow or creep so it is really not an effective material.
The composite graphite I'm familiar with is a layered graphite with an acrylic sandwich in between. The material has been excellent in that it is very light weight but quite strong, and yet we have had difficulty controlling strong forces, such as you get with a forefoot varus or bordedine equinus or in an individual who is particularly heavy or active. Composite graphite tends to fracture quite easily. I think it has quite a way to go yet before it is as good as rohadur.
What properties should the "ideal" functional orthotic material have?
The material has to be somewhat flexible. But it also has to have a sufficient resistance to resist the abnormal forces that are created during the process of locomotion. Let's take an example of treating plantar calcaneal heel pain associated with mechanical heel spurs. Remember, I'm talking about pain from a mechanical spur, not caused by arthritis or other medical reason. When I was in practice I had one case that took about six months before the pain resolved; all the other cases resolved within one month or less. I never needed to resort to surgery during the entire time I was in practice to treat heel pain.
I was able to differentiate mechanical from other etiologies just by the break in the Cyma line. But the critical thing was that we had a rohadur at that time that was a little more flexible than the rohadur commonly in use today. We didn't realize the significance of that until it was discovered that some component used in the fabrication of rohadur was carcinogenic. As a result, the material was changed and the newer rohadur was a little bit darker and also a little more rigid.
When this new, more rigid material came out, doctors who had been using the earlier rohadur successfully began reporting a ten to fifteen percent failure rate in treating mechanical spurs. Then surgery was needed. And these are the very people who were getting the same excellent results that I did when I was in practice. So I would say as far as flexibility is concerned, the amount of flodbility in the old rohadur would be just about ideal. On the other hand, the old rohadur broke much more readily than the new one and also changed its shape within a period of one or two years with a person who had a major foot problem. The new rohadur can last as long as fifteen years, even in major foot problems.
How do you feel about the use of soft orthosys to control biomechanical imbalances?
I don't believe you can control them.
Under what conditions and for what problems do you advocate surgical intervention?
When we can't solve the problem short of surgery. For years people have thought that I was against surgery. I'm a strong advocate of surgery - but only surgery that is well indicated. I believe that research in surgery has a long way to go and its basis is biomechanics.
Do you contend that you can always solve the problem short of surgery?
No, not at all. My statement is that if you perform surgery without doing anything about the cause, the symptoms are going to recur in time and, therefore, you're doing the same thing the pediatrist used to do when he took the corn or callous off and had the patient come back once a month. The only difference is it's a little more sophisticated - they last three or five years before they come back for another surgery. Now, the difference is that when a doctor controls the function of a foot anci performs surgery, then he should have a long-term result as long as he can control function because he has eliminated the etiology of the problem. He can expect twenty to twenty-five years or longer with regard to his result.
Podiatry Today Cover, 1989.
What treatment protocol do you recommend to the podiatrist who sees a patient who has never been treated before and presents with moderately advanced subluxations and deformities of a fixed variety?
Take hallux valgus as an example. If the first IM angle exceeds 12o° you cannot reverse it with orthosis. You may relieve the symptoms, but you're not going to reverse the bunion deformity or the hallux valgus deformity. So this is definitely a patient that requires surgery. However, before I perform surgery on a patient like that, there are two things I want to do:
- first determine that I can control function;
- wait for the inflammation in thc first MP joint to subside.
I feel that a non-inflamed articulation is a better surgical candidate than an inflamed one. I found that I had less postoperative spasms and complications later.
Okay, so you prepared the foot beforehand. Would you define forefoot supinatus and compare it to forefoot varus?
Forefoot supinatus is a fixed position of supination of the forefoot about the longitudinal axis of the midtarsal joint. In other word, if the foot has a normal range of motion in the forefoot, the forefoot can invert relative to the rear foot and actually supinates. It moves in three planes, but the primary motion that you see is inversion. And so, if it moved into that position and became fixed by soft tissue, we would see an inverted forefoot that would look like a forefoot varus. If a foot has been functioning in a pronated position for many years, the forefoot is in an inverted position all the time and becomes somewhat fixed in that position. A forefoot varus is a structural deformity of the foot in which the forefoot is fixed in an inverted position because of a structural abnormality some place within the midtarsal joint. We don't know what a forefoot varus is. I see clinically what I believe to be three different types of forefoot varus conditions. But it's purely surmised at the present time because we haven't had the opportunity to study this on freshly amputated specimens the way we should.
Some controversy exists about whether there is such a thing as a forefoot valgus. Can you clafify that?
Theres no question in my mind that there is forefoot valgus, but people tend to confuse forefoot valgus with a congenital plantar flexed first ray. In other words, the forefoot can be everted because of a midtarsal joint deformity or it can be everted because the first my is plantar flexed. Even when the second ray is plantar flexed, an everted forefoot deformity is produced. When the first ray is congenitally plantar flexed, then you see a major degree of forefoot eversion. When it's an acquired plantar flexed deformity, then it's a very minimal forefoot eversion. But I've seen a three-month-old child who had a 35° everted forefoot deformity that was caused by a planter flexed first ray. It was so great that it couldn't be reduced completely by surgery. The child will require several surgeries during the course of its lifetime to correct that degree of deformity.
The maximum degree of everted forefoot deformity, particularly forefoot valgus, that I have succesfully treated with orthoses has been 21°. Beyond that you start getting into difficulty because of the lack of space within the shoe.
Is there such a thing as a true posterior cavus deformity, or is this observed only as a compensation for anterior cavus?
I dont like the term cavus. A cavus just means a high-arch foot - whether it's high in the back or in the front. What came first - the chicken or the egg? If we have a plantar flexed deformity of the forefoot, that means a whole forefoot is lower than the rear foot. If you put that foot on the floor the rear foot is going to become elevated, isnt it?
Sounds logical.
And so, what's to say that it's a forefoot or anterior cavus or a rear cavus? In other words, what we have to do is describe the joint at which the deformity occurs and the direction of that deformity. So I can't even get into a discussion on something that I don't understand.
Typically, chronic ankle sprains are due to a rear foot varus. Yet foot surgeons presently tend to use the peroneus brevis tendon, which we know is the best pronator of the foot, in the surgical repair. Doesn't that worsen the pre-existing inverted position?
I disagree with muscle transplants for structural problems that can be treated with orthoses. If you have a rear foot varus that is laterally unstable you can use a very high lateral heel cup and a lateral flare on the rear foot post and control it quite adequately for a basketball player or runner or even a person who's just walking. It is unnecessary to resort to surgery. In fact, I think that is indiscriminate surgery.
Would you consider it indiscriminate to surgically correct chronic latelal ankle instability?
Yes. A patient with a severely plantar flexed first ray deformity for which a subtalar joint fusion was performed was referred to me. The talus had come completely out of the ankle mortise. Ankle surgery had been recommended for him. Let's think about it: the plantar flexed first ray inverts the rear foot when the midtarsal joint can't invert any further. The rear foot tends to supinate at the subtalar joint and invert, putting an inversion force into the ankle joint. When the doctors decided they wanted to treat this individual to straighten up his heel, they did a triple arthrodesis on him, But they didn't do anything about the planar flexed first ray. As a result, the inverted force was referred to the ankle and the joint subluxed. So now they were talking about arthrodesing the ankle joint. If they had done that, the next thing to go would be the knee and then the hip. Instead, we put an orthosis on the individual that supported the everted forefoot and actually reduced the subluxation of the ankle. We succeeded in moving the talus back into the ankle mortise and we recommended that he have planar flexed first ray surgery. It has been fifteen years and he hasn't agreed to it because he is getting along so well. This is what I mean about people performing surgery when they don't understand pathology.
Joint implants have not been particularly effective or, at least, they haven't lived up to their expectations. From a biomechanical perspective, why is this?
I don t think people are controlling pronation, so the forces that are causing the stress on the implant are still present.
If you wanted to design a total first metatarsal phalangeal joint implant, could you do anything to boost its longevity from a biomechanical stress aspect?
Not with regard to designing the implant.
With the functional approach?
With the functional approach, the result will be much better.
Interview: Back to the Root
If you adopted just the functional approach, would the implant be needed?
Without the implant, say we performed the Keller bunionectomy, it might take a year or more before that Keller became functional. When we used implants fifteen or more years ago (before implants were as sophisticated as they are now) and an orthosis afterward, we found the hallux might become functional again and actuaily bear weight in as little as three months. So from the standpoint of function, there was an advantage.
lf a patient has an extremely painful pathologic sesamoid bone, would you recommend its removal?
If it's the bone that's causing the pain, yes.
So that's a trick answer to my trick question, right?
Yes.
You have given a lot to your profession in terms of collating, documenting, researching, proving, writing - creating a body of knowledge that didn't exist in one place before. You made your theories and your proposals public. Why?
It was because of my frustration in trying to teach and finding that I was very ineffective as a teacher. So I began to try to put it into literature, hoping that it would increase the number of people who became knowledgeable. I still find, however that the most knowledgeable people I know in the field of biomechanics are those who are working with our laboratory where we have the chance to meet with them once a year. According to them and anyone else who's attended, it's supposed to be the best seminar in the United States every vear because everybody participates. And if anyone has anything to suggest or disagrees with us, we get into some royal battles. It's fun.
Do you win?
Sometimes.
Thank you, Dr.Root.
Podiatry Today:
EXCLUSIVE INTERVIEW
Merton Root, pioneer in biomechanics
Published: October 1989
Back to the Root - Q&A
Mention podiatric biomechanics and the name Merton Root immediately comes to mind. Indeed, Normal and Abnormal Function of the Foot, which Dr. Root co-authored with William Orien and John Weed, is the bible of foot orthopedics. Yet for the past several years, little has been heard from this legendary figure, whose painstaking research into classification, pathology, and treatment will influence podiatrists for generations to come. From his California home, Dr. Root granted an exclusive telephone interview to executive editor Judith A. Rubenstein and Board of Editorial Consultants chairman Harold Rubenstein, D.P.M. An edited transcript follows.
What have you been doing for the past several years?
I don't maintain an office. I have rheumatoid arthritis, and I had to leave practice more than twelve years ago. But we have a laboratory, and occasionally conduct seminars for some of our customers. I also do some consulution and teaching.
Admittedly, foot orthopedics is a complex subject. But some people have suggested that you have made it more complicated than it really is. Would you agree?
I have just barely scratched the surface. What I don't know could fill many books.
Are you planning to publish another book?
Well, I haven't written anything on the structural abnormalities that I've found over the years. There are about twenty-five or thirty of them that need to be described in detail, as well as the treatment and prescription for them. The initial volume on examination of the foot needs to be upgraded and expanded. We knew that at the time we wrote it, but we didn't want to scare people off either.
Did you ever imagine the extensive impact your research would have on practitioners around the world?
In the 1960s I began to lecture nationwide - every two weeks I traveled to a different city for three days. During my lectures, men would break down and cry because my lecture shook them up. They were totally frustrated that they were so far behind - that this material had been out there and they'd gone to school and hadn't received it. I couldn't believe the impact I had on people. Yet rather than being excited about receiving something new, it created the opposite effect - total frustration and anger and other emotions that amazed me.
Nevertheless, you are highly regarded.
I don't know why. Perhaps it's because I'm very outspoken.
What was the extent of knowledge about foot orthopedics before you began lecturing and publishing?
Let me go back a little further than that. What we learned about orthopedics when I went to school was purely empirical. People would do things, obtain results, and it became a methodology - just because something good happened. Unfortunately, there was no clearly defined scientific terminology to describe position, motion, or anything of that nature. There were no clear-cut methods to determine foot type. ln fact, there was no real classification of feet. As a result, the primary classifications that doctors used were first, second, and third degree weak foot. The treatment was pretty much the same - it didn't make any difference what you were treating. Unfortunately since practitioners didn't understand the etiology that caused the symptoms, patients didn't respond well to treatment.
So you found your niche in the profession?
I initially went into podiatry because I was interested in research.
Merton Root at California College of Chiropody (now California School of Podiatric Medicine) in San Francisco, graduating in 1952.
Where did you study?
I graduated from the California College in 1952. In those days school was quite easy, but people didn't like the ideas of research or investigation. I can remember telling my orthopedics professor, Dr. Norman Burgeq who was also the school's dean, that I had so much time on my hands I was playing a lot of bridge. I'd rather spend that time working on some research project. He told me I was better off playing bridge.
That's how you got into biomechanics?
I didn't realize it was biomechanics. Starting in my freshman year, I became very interested in the physiology of the neurological system. I ran across the concept of proprioception. Thnis was never taught in podiatry schools, but it really impressed me as a very important area of physiology that should be taught.
Why is proprioception so important?
It is critical to the mechanics of the body. As I asked questions about the cause of different symptoms, I began to realize that nobody understood what caused a corn or a callous or a bunion - or much of anything that we were treating. It was all symptomatic treatment. We had no knowledge of function. When I left school, I began to pursue function, but I couldn't understand function until I understood foot morphology - the structure of the foot. I recalled from my reading in botany that Linnaeus classified plants according to their morphology, their shape and structure. I decided that's where I would start.
To classify feet?
Well, I began to try to classify feet. But I found as they move from one position to another, there is no consistency in the structural relationship from one part to another. So I had to find some reference point at which I could put the foot so that I could compare one foot to another. I worked on the subtalar joint for about a year measuring it, trying to understand it. I had been pondering the variances that I was finding in my measurements. One morning in 1954, just by luck I guess, I was standing in the shower without any thought about the foot and all of a sudden the concept of the neutral subtalar joint position flashed into my mind. I could hardly wait to get to the office to substantiate it. That's what turned out to be the key to my being able to contribute to podiatry.
Until that time were there any references to this in the orthopedic literature?
No.
Subtalar Joint Excursion
Were you doing these measurements on your patients?
Yes, but we had no consistent way of measuring because until I found the neutral position of the subtalar joint, we had no consistent reference point. So measurements varied.
What happened once you esablished the neutral point?
Then I was able to measure the entire lower extremity from the hip down.
Is there a verified normal range of motion in degrees to the midtarsal joints?
No. I don't believe in normal range of motion. I believe that if an individual has adequate range of motion for the functions that individual is using the parts for, that's the normal range of motion. But to say that the average in a hundred people is 20°, therefore that's a normal range of motion - this is poppycock.
So you evaluate case by case?
Yes. An athlete (who needs a greater range of motion) doesn't have a normal range of motion if he can't perform the functions he needs to perform as an athlete. For example, one of our laboratory employees is a long-disance runner. She has an internal femoral torsion at the hip which wouldn't bother someone who was just walking and using that extremity for every-day work. But when she was running up to ten miles a day, she developed stress fractures at the hip because it was exceeding its range of motion and actually jamming against the acetabulum. She had an adequate range of motion for walking and functioning, but for her athletic activity, she didn't, and she paid the price.
How did the term "functional orthosis" evolve?
That's my term. To my knowledge, the only functional orthosis that we had prior to what I came up with is the Whitman orthosis. It was based on the principle that if you started to pronate the foot, the orthosis would gouge the navicular area of the foot, be uncomforable and when the person used his muscles he would tend to resupinate the foot. The Whitman orthosis was used to treat children's feet. Unfortunately, it was based on some inadequate scientific concepts and wasn't too successful, although it was still in use when I first began to practice.
Have you of your colleagues been able to document systemic effects related to the use of functional orthosis?
Yes, particularly postural problems. Unfortunately, I've never had the time or opportunity to write about it. Maybe I had the opportunity, but I've been too lazy. We've been able to correlate symptomatic syndromes with various types of foot abnormalities. For insance, rear foot varus will produce a complex in which the lateral thigh muscles become tender and the erector spinatus muscle on the side opposite the foot deformity goes into spasm. That spasm then carries on up the spine and will produce a scalenus anticus syndrome on the opposite side of the trunk, on the same side as the foot deformity. We've found symptomatic and other types of correlations with functional limb shortages and structural shorages. With the loss of shock absorption you have a very serious spasm associated with the lumbar spine. Each one of these particular entities has its own peculiar symptomatic pattern that develops. We've been able to treat these people and relieve the spasm or the problem that was present. But if we took the orthosis away, the problem would return. Put the orthosis back on the patient and the problem disappeared. We could repeat this for three times in a row and reconfirm each time that there was a definite cause and effect relationship.
Undoubtedly, many podiatrists have cases like that, but perhaps they are hesitant to acknowledge the cause of their successful treatment because they can't document it.
But they very definitely can. I've treated a nineteen-year-old girl with a head tilt due to a functional limb shortage. In fact, I straightened up the head tilt so rapidly that she developed migraine headaches, so we had to slow down. Postural problems can indeed be treated. The key is that people have made statements in the past and haven't confirmed them. It's a very simple matter. For instance, orthoses can sometimes cause back pain. I would see two to three cases each year where for some unexplained reason - and I still can't explain it - people would develop acute low back pain. I would take the orthosis away, the back pain would go away, put it back on and it would return. Then I would take the post off and allow greater range of motion. One or two of the patients could tolerate the orthosis without any pain. But others continued to have back pain, so we had to remove the orthosis. There was no way to treat them.
Controversy still rages over whether or not children should be treated for biomechanical pathology, such as a compensated calcaneal varus that's excessive for their age. What is your recommendation?
Primarily the battle continues out of ignorance. If you are looking at flat feet and that is your classification or determination for whether or not a child should be treated, I can see a problem. From birth until the adult contour develops at approximately seven to eight years of age, a child normally has flat feet. In fact, if a child doesn't have flat feet, something is wrong with the foot. So, the child's foot, which is more fleshy, should be low arched and somewhat flat. But many podiatrists end up treating such truly normal feet just because they are relatively flat. The same thing is true of the pediatrician who looks at flat feet and says: "Don't worry about it, the child will outgrow it." And that is true - if it is a normal foot that is flat.
What it really comes down to is: does the doctor have the capability of differentiating whether a flat foot is normal or abnormal? Can he determine what that abnormality is? Is he capable of treating it with orthoses? If he is, then he should treat it because these abnormal forces that cause the foot to function abnormally cause a retention of juvenile ontogeny. Basically, if you look at a subluxed adult foot, you are observing a retention of the foot's shape from about the time the child first began to walk. A foot can sublux beyond that point, for example a compensated equinus, and actually become worse than the juvenile position. Nevertheless, most subluxed feet are just the retention of that very weak juvenile position, a foot that is not capable of normal bipedal locomotion.
Are you in favor of treating truly abnormal biomechanical deformities in children?
Very definitely. By resisting those abnormal forces, you allow normal ontogeny to develop, leading to a more sound structural foot by the time the child is an adult.
In my experience, the person who pronates abnormally will develop symptoms, but they are usually very insignificant symptoms and seldom painful. A good example of that is a compensated rear foot varus where the foot pronates to the vertical and is the only problem in the lower extremity. That person will see a podiatrist about once a year to have the callous pared off the sole of the foot. Sometimes the bunion will develop to a point where it will be slightly tender. But the person usually doesn't want - or need - any major treatment. However, put that same amount of pronation into a foot that is subluxed, a foot that has a juvenile ontogeny. Now because of the structural instability of the foot itself, compounded by the instability caused by pronation and the ensuing traumatic shearing forces, the symptomatic changes are probably ten times as bad. That becomes a very acute foot problem.
Charcot Foot
I have seen normal adult feet that suddenly collapse, sublux and become totally flat, as, for example, a Charcot's foot. That can happen. But most of what we see is merely a retention of juvenile ontogeny.
Let me qualify what I've just said because this concept has never been confirmed, and the ten percent figure I've used may be way off. A subluxed foot that pronates abnormally is much more symptomatic than a non-subluxed foot that pronates abnormally.
Here is a Rohadur orthotic on pitcher Gaylord Perry. Also next to Merton Root is Jack Haitt and a trainer stands between.
Is there any documentation to dempylene, graphite and rohadur?
We've worked with those in our laboratory. The polypropylene will change shape just by its own weight. For functional control it is too flexible. It has too much molecular flow or creep so it is really not an effective material.
The composite graphite I'm familiar with is a layered graphite with an acrylic sandwich in between. The material has been excellent in that it is very light weight but quite strong, and yet we have had difficulty controlling strong forces, such as you get with a forefoot varus or bordedine equinus or in an individual who is particularly heavy or active. Composite graphite tends to fracture quite easily. I think it has quite a way to go yet before it is as good as rohadur.
What properties should the "ideal" functional orthotic material have?
The material has to be somewhat flexible. But it also has to have a sufficient resistance to resist the abnormal forces that are created during the process of locomotion. Let's take an example of treating plantar calcaneal heel pain associated with mechanical heel spurs. Remember, I'm talking about pain from a mechanical spur, not caused by arthritis or other medical reason. When I was in practice I had one case that took about six months before the pain resolved; all the other cases resolved within one month or less. I never needed to resort to surgery during the entire time I was in practice to treat heel pain.
I was able to differentiate mechanical from other etiologies just by the break in the Cyma line. But the critical thing was that we had a rohadur at that time that was a little more flexible than the rohadur commonly in use today. We didn't realize the significance of that until it was discovered that some component used in the fabrication of rohadur was carcinogenic. As a result, the material was changed and the newer rohadur was a little bit darker and also a little more rigid.
When this new, more rigid mateial came out, doctors who had been using the earlier rohadur successfully began reporting a ten to fifteen percent failure rate in treating mechanical spurs. Then surgery was needed. And these are the very people who were getting the same excellent results that I did when I was in practice. So I would say as far as flexibility is concerned, the amount of flodbility in the old rohadur would be just about ideal. On the other hand, the old rohadur broke much more readily than the new one and also changed its shape within a period of one or two years with a person who had a major foot problem. The new rohadur can last as long as fifteen years, even in major foot problems.
How do you feel about the use of soft orthosys to control biomechanical imbalances?
I don't believe you can control them.
Under what conditions and for what problems do you advocate surgical intervention?
When we can't solve the problem short of surgery. For years people have thought that I was against surgery. I'm a strong advocate of surgery - but only surgery that is well indicated. I believe that research in surgery has a long way to go and its basis is biomechanics.
Do you contend that you can always solve the problem short of surgery?
No, not at all. My statement is that if you perform surgery without doing anything about the cause, the symptoms are going to recur in time and, therefore, you're doing the same thing the pediatrist used to do when he took the corn or callous off and had the patient come back once a month. The only difference is it's a little more sophisticated - they last three or five years before they come back for another surgery. Now, the difference is that when a doctor controls the function of a foot anci performs surgery, then he should have a long-term result as long as he can control function because he has eliminated the etiology of the problem. He can expect twenty to twenty-five years or longer with regard to his result.
Podiatry Today Cover, 1989.
What treatment protocol do you recommend to the podiatrist who sees a patient who has never been treated before and presents with moderately advanced subluxations and deformities of a fixed variety?
Take hallux valgus as an example. If the first IM angle exceeds 12o° you cannot reverse it with orthosis. You may relieve the symptoms, but you're not going to reverse the bunion deformity or the hallux valgus deformity. So this is definitely a patient that requires surgery. However, before I perform surgery on a patient like that, there are two things I want to do:
- first determine that I can control function;
- wait for the inflammation in thc first MP joint to subside.
I feel that a non-inflamed articulation is a better surgical candidate than an inflamed one. I found that I had less postoperative spasms and complications later.
Okay, so you prepared the foot beforehand. Would you define forefoot supinatus and compare it to forefoot varus?
Forefoot supinatus is a fixed position of supination of the forefoot about the longitudinal axis of the midtarsal joint. In other word, if the foot has a normal range of motion in the forefoot, the forefoot can invert relative to the rear foot and actually supinates. It moves in three planes, but the primary motion that you see is inversion. And so, if it moved into that position and became fixed by soft tissue, we would see an inverted forefoot that would look like a forefoot varus. If a foot has been functioning in a pronated position for many years, the forefoot is in an inverted position all the time and becomes somewhat fixed in that position. A forefoot varus is a structural deformity of the foot in which the forefoot is fixed in an inverted position because of a structural abnormality some place within the midtarsal joint. We don't know what a forefoot varus is. I see clinically what I believe to be three different types of forefoot varus conditions. But it's purely surmised at the present time because we haven't had the opportunity to study this on freshly amputated specimens the way we should.
Some controversy exists about whether there is such a thing as a forefoot valgus. Can you clafify that?
Theres no question in my mind that there is forefoot valgus, but people tend to confuse forefoot valgus with a congenital plantar flexed first ray. In other words, the forefoot can be everted because of a midtarsal joint deformity or it can be everted because the first my is plantar flexed. Even when the second ray is plantar flexed, an everted forefoot deformity is produced. When the first ray is congenitally plantar flexed, then you see a major degree of forefoot eversion. When it's an acquired plantar flexed deformity, then it's a very minimal forefoot eversion. But I've seen a three-month-old child who had a 35° everted forefoot deformity that was caused by a planter flexed first ray. It was so great that it couldn't be reduced completely by surgery. The child will require several surgeries during the course of its lifetime to correct that degree of deformity.
The maximum degree of everted forefoot deformity, particularly forefoot valgus, that I have succesfully treated with orthoses has been 21°. Beyond that you start getting into difficulty because of the lack of space within the shoe.
Is there such a thing as a true posterior cavus deformity, or is this observed only as a compensation for anterior cavus?
I dont like the term cavus. A cavus just means a high-arch foot - whether it's high in the back or in the front. What came first - the chicken or the egg? If we have a plantar flexed deformity of the forefoot, that means a whole forefoot is lower than the rear foot. If you put that foot on the floor the rear foot is going to become elevated, isnt it?
Sounds logical.
And so, what's to say that it's a forefoot or anterior cavus or a rear cavus? In other words, what we have to do is describe the joint at which the deformity occurs and the direction of that deformity. So I can't even get into a discussion on something that I don't understand.
Typically, chronic ankle sprains are due to a rear foot varus. Yet foot surgeons presently tend to use the peroneus brevis tendon, which we know is the best pronator of the foot, in the surgical repair. Doesn't that worsen the pre-existing inverted position?
I disagree with muscle transplants for structural problems that can be treated with orthoses. If you have a rear foot varus that is laterally unstable you can use a very high lateral heel cup and a lateral flare on the rear foot post and control it quite adequately for a basketball player or runner or even a person who's just walking. It is unnecessary to resort to surgery. In fact, I think that is indiscriminate surgery.
Would you consider it indiscriminate to surgically correct chronic latelal ankle instability?
Yes. A patient with a severely plantar flexed first ray deformity for which a subtalar joint fusion was performed was referred to me. The talus had come completely out of the ankle mortise. Ankle surgery had been recommended for him. Let's think about it: the plantar flexed first ray inverts the rear foot when the midtarsal joint can't invert any further. The rear foot tends to supinate at the subtalar joint and invert, putting an inversion force into the ankle joint. When the doctors decided they wanted to treat this individual to straighten up his heel, they did a triple arthrodesis on him, But they didn't do anything about the planar flexed first ray. As a result, the inverted force was referred to the ankle and the joint subluxed. So now they were talking about arthrodesing the ankle joint. If they had done that, the next thing to go would be the knee and then the hip. Instead, we put an orthosis on the individual that supported the everted forefoot and actually reduced the subluxation of the ankle. We succeeded in moving the talus back into the ankle mortise and we recommended that he have planar flexed first ray surgery. It has been fifteen years and he hasn't agreed to it because he is getting along so well. This is what I mean about people performing surgery when they don't understand pathology.
Joint implants have not been particularly effective or, at least, they haven't lived up to their expectations. From a biomechanical perspective, why is this?
I don t think people are controlling pronation, so the forces that are causing the stress on the implant are still present.
If you wanted to design a total first metatarsal phalangeal joint implant, could you do anything to boost its longevity from a biomechanical stress aspect?
Not with regard to designing the implant.
With the functional approach?
With the functional approach, the result will be much better.
Interview: Back to the Root
If you adopted just the functional approach, would the implant be needed?
Without the implant, say we performed the Keller bunionectomy, it might take a year or more before that Keller became functional. When we used implants fifteen or more years ago (before implants were as sophisticated as they are now) and an orthosis afterward, we found the hallux might become functional again and actuaily bear weight in as little as three months. So from the standpoint of function, there was an advantage.
lf a patient has an extremely painful pathologic sesamoid bone, would you recommend its removal?
If it's the bone that's causing the pain, yes.
So that's a trick answer to my trick question, right?
Yes.
You have given a lot to your profession in terms of collating, documenting, researching, proving, writing - creating a body of knowledge that didn't exist in one place before. You made your theories and your proposals public. Why?
It was because of my frustration in trying to teach and finding that I was very ineffective as a teacher. So I began to try to put it into literature, hoping that it would increase the number of people who became knowledgeable. I still find, however that the most knowledgeable people I know in the field of biomechanics are those who are working with our laboratory where we have the chance to meet with them once a year. According to them and anyone else who's attended, it's supposed to be the best seminar in the United States every vear because everybody participates. And if anyone has anything to suggest or disagrees with us, we get into some royal battles. It's fun.
Do you win?
Sometimes.
Thank you, Dr.Root.
Podiatry Today:
EXCLUSIVE INTERVIEW
Merton Root, pioneer in biomechanics
Published: October 1989
Back to the Root - Q&A
Mention podiatric biomechanics and the name Merton Root immediately comes to mind. Indeed, Normal and Abnormal Function of the Foot, which Dr. Root co-authored with William Orien and John Weed, is the bible of foot orthopedics. Yet for the past several years, little has been heard from this legendary figure, whose painstaking research into classification, pathology, and treatment will influence podiatrists for generations to come. From his California home, Dr. Root granted an exclusive telephone interview to executive editor Judith A. Rubenstein and Board of Editorial Consultants chairman Harold Rubenstein, D.P.M. An edited transcript follows.
What have you been doing for the past several years?
I don't maintain an office. I have rheumatoid arthritis, and I had to leave practice more than twelve years ago. But we have a laboratory, and occasionally conduct seminars for some of our customers. I also do some consulution and teaching.
Admittedly, foot orthopedics is a complex subject. But some people have suggested that you have made it more complicated than it really is. Would you agree?
I have just barely scratched the surface. What I don't know could fill many books.
Are you planning to publish another book?
Well, I haven't written anything on the structural abnormalities that I've found over the years. There are about twenty-five or thirty of them that need to be described in detail, as well as the treatment and prescription for them. The initial volume on examination of the foot needs to be upgraded and expanded. We knew that at the time we wrote it, but we didn't want to scare people off either.
Did you ever imagine the extensive impact your research would have on practitioners around the world?
In the 1960s I began to lecture nationwide - every two weeks I traveled to a different city for three days. During my lectures, men would break down and cry because my lecture shook them up. They were totally frustrated that they were so far behind - that this material had been out there and they'd gone to school and hadn't received it. I couldn't believe the impact I had on people. Yet rather than being excited about receiving something new, it created the opposite effect - total frustration and anger and other emotions that amazed me.
Nevertheless, you are highly regarded.
I don't know why. Perhaps it's because I'm very outspoken.
What was the extent of knowledge about foot orthopedics before you began lecturing and publishing?
Let me go back a little further than that. What we learned about orthopedics when I went to school was purely empirical. People would do things, obtain results, and it became a methodology - just because something good happened. Unfortunately, there was no clearly defined scientific terminology to describe position, motion, or anything of that nature. There were no clear-cut methods to determine foot type. ln fact, there was no real classification of feet. As a result, the primary classifications that doctors used were first, second, and third degree weak foot. The treatment was pretty much the same - it didn't make any difference what you were treating. Unfortunately since practitioners didn't understand the etiology that caused the symptoms, patients didn't respond well to treatment.
So you found your niche in the profession?
I initially went into podiatry because I was interested in research.
Merton Root at California College of Chiropody (now California School of Podiatric Medicine) in San Francisco, graduating in 1952.
Where did you study?
I graduated from the California College in 1952. In those days school was quite easy, but people didn't like the ideas of research or investigation. I can remember telling my orthopedics professor, Dr. Norman Burgeq who was also the school's dean, that I had so much time on my hands I was playing a lot of bridge. I'd rather spend that time working on some research project. He told me I was better off playing bridge.
That's how you got into biomechanics?
I didn't realize it was biomechanics. Starting in my freshman year, I became very interested in the physiology of the neurological system. I ran across the concept of proprioception. This was never taught in podiatry schools, but it really impressed me as a very important area of physiology that should be taught.
Why is proprioception so important?
It is critical to the mechanics of the body. As I asked questions about the cause of different symptoms, I began to realize that nobody understood what caused a corn or a callous or a bunion - or much of anything that we were treating. It was all symptomatic treatment. We had no knowledge of function. When I left school, I began to pursue function, but I couldn't understand function until I understood foot morphology - the structure of the foot. I recalled from my reading in botany that Linnaeus classified plants according to their morphology, their shape and structure. I decided that's where I would start.
To classify feet?
Well, I began to try to classify feet. But I found as they move from one position to another, there is no consistency in the structural relationship from one part to another. So I had to find some reference point at which I could put the foot so that I could compare one foot to another. I worked on the subtalar joint for about a year measuring it, trying to understand it. I had been pondering the variances that I was finding in my measurements. One morning in 1954, just by luck I guess, I was standing in the shower without any thought about the foot and all of a sudden the concept of the neutral subtalar joint position flashed into my mind. I could hardly wait to get to the office to substantiate it. That's what turned out to be the key to my being able to contribute to podiatry.
Until that time were there any references to this in the orthopedic literature?
No.
Subtalar Joint Excursion
Were you doing these measurements on your patients?
Yes, but we had no consistent way of measuring because until I found the neutral position of the subtalar joint, we had no consistent reference point. So measurements varied.
What happened once you esablished the neutral point?
Then I was able to measure the entire lower extremity from the hip down.
Is there a verified normal range of motion in degrees to the midtarsal joints?
No. I don't believe in normal range of motion. I believe that if an individual has adequate range of motion for the functions that individual is using the parts for, that's the normal range of motion. But to say that the average in a hundred people is 20°, therefore that's a normal range of motion - this is poppycock.
So you evaluate case by case?
Yes. An athlete (who needs a greater range of motion) doesn't have a normal range of motion if he can't perform the functions he needs to perform as an athlete. For example, one of our laboratory employees is a long-disance runner. She has an internal femoral torsion at the hip which wouldn't bother someone who was just walking and using that extremity for every-day work. But when she was running up to ten miles a day, she developed stress fractures at the hip because it was exceeding its range of motion and actually jamming against the acetabulum. She had an adequate range of motion for walking and functioning, but for her athletic activity, she didn't, and she paid the price.
How did the term "functional orthosis" evolve?
That's my term. To my knowledge, the only functional orthosis that we had prior to what I came up with is the Whitman orthosis. It was based on the principle that if you started to pronate the foot, the orthosis would gouge the navicular area of the foot, be uncomforable and when the person used his muscles he would tend to resupinate the foot. The Whitman orthosis was used to treat children's feet. Unfortunately, it was based on some inadequate scientific concepts and wasn't too successful, although it was still in use when I first began to practice.
Have you of your colleagues been able to document systemic effects related to the use of functional orthosis?
Yes, particularly postural problems. Unfortunately, I've never had the time or opportunity to write about it. Maybe I had the opportunity, but I've been too lazy. We've been able to correlate symptomatic syndromes with various types of foot abnormalities. For insance, rear foot varus will produce a complex in which the lateral thigh muscles become tender and the erector spinatus muscle on the side opposite the foot deformity goes into spasm. That spasm then carries on up the spine and will produce a scalenus anticus syndrome on the opposite side of the trunk, on the same side as the foot deformity. We've found symptomatic and other types of correlations with functional limb shortages and structural shorages. With the loss of shock absorption you have a very serious spasm associated with the lumbar spine. Each one of these particular entities has its own peculiar symptomatic pattern that develops. We've been able to treat these people and relieve the spasm or the problem that was present. But if we took the orthosis away, the problem would return. Put the orthosis back on the patient and the problem disappeared. We could repeat this for three times in a row and reconfirm each time that there was a definite cause and effect relationship.
Undoubtedly, many podiatrists have cases like that, but perhaps they are hesitant to acknowledge the cause of their successful treatment because they can't document it.
But they very definitely can. I've treated a nineteen-year-old girl with a head tilt due to a functional limb shortage. In fact, I straightened up the head tilt so rapidly that she developed migraine headaches, so we had to slow down. Postural problems can indeed be treated. The key is that people have made statements in the past and haven't confirmed them. It's a very simple matter. For instance, orthoses can sometimes cause back pain. I would see two to three cases each year where for some unexplained reason - and I still can't explain it - people would develop acute low back pain. I would take the orthosis away, the back pain would go away, put it back on and it would return. Then I would take the post off and allow greater range of motion. One or two of the patients could tolerate the orthosis without any pain. But others continued to have back pain, so we had to remove the orthosis. There was no way to treat them.
Controversy still rages over whether or not children should be treated for biomechanical pathology, such as a compensated calcaneal varus that's excessive for their age. What is your recommendation?
Primarily the battle continues out of ignorance. If you are looking at flat feet and that is your classification or determination for whether or not a child should be treated, I can see a problem. From birth until the adult contour develops at approximately seven to eight years of age, a child normally has flat feet. In fact, if a child doesn't have flat feet, something is wrong with the foot. So, the child's foot, which is more fleshy, should be low arched and somewhat flat. But many podiatrists end up treating such truly normal feet just because they are relatively flat. The same thing is true of the pediatrician who looks at flat feet and says: "Don't worry about it, the child will outgrow it." And that is true - if it is a normal foot that is flat.
What it really comes down to is: does the doctor have the capability of differentiating whether a flat foot is normal or abnormal? Can he determine what that abnormality is? Is he capable of treating it with orthoses? If he is, then he should treat it because these abnormal forces that cause the foot to function abnormally cause a retention of juvenile ontogeny. Basically, if you look at a subluxed adult foot, you are observing a retention of the foot's shape from about the time the child first began to walk. A foot can sublux beyond that point, for example a compensated equinus, and actually become worse than the juvenile position. Nevertheless, most subluxed feet are just the retention of that very weak juvenile position, a foot that is not capable of normal bipedal locomotion.
Are you in favor of treating truly abnormal biomechanical deformities in children?
Very definitely. By resisting those abnormal forces, you allow normal ontogeny to develop, leading to a more sound structural foot by the time the child is an adult.
In my experience, the person who pronates abnormally will develop symptoms, but they are usually very insignificant symptoms and seldom painful. A good example of that is a compensated rear foot varus where the foot pronates to the vertical and is the only problem in the lower extremity. That person will see a podiatrist about once a year to have the callous pared off the sole of the foot. Sometimes the bunion will develop to a point where it will be slightly tender. But the person usually doesn't want - or need - any major treatment. However, put that same amount of pronation into a foot that is subluxed, a foot that has a juvenile ontogeny. Now because of the structural instability of the foot itself, compounded by the instability caused by pronation and the ensuing traumatic shearing forces, the symptomatic changes are probably ten times as bad. That becomes a very acute foot problem.
Charcot Foot
I have seen normal adult feet that suddenly collapse, sublux and become totally flat, as, for example, a Charcot's foot. That can happen. But most of what we see is merely a retention of juvenile ontogeny.
Let me qualify what I've just said because this concept has never been confirmed, and the ten percent figure I've used may be way off. A subluxed foot that pronates abnormally is much more symptomatic than a non-subluxed foot that pronates abnormally.
Here is a Rohadur orthotic on pitcher Gaylord Perry. Also next to Merton Root is Jack Haitt and a trainer stands between.
Is there any documentation to dempylene, graphite and rohadur?
We've worked with those in our laboratory. The polypropylene will change shape just by its own weight. For functional control it is too flexible. It has too much molecular flow or creep so it is really not an effective material.
The composite graphite I'm familiar with is a layered graphite with an acrylic sandwich in between. The material has been excellent in that it is very light weight but quite strong, and yet we have had difficulty controlling strong forces, such as you get with a forefoot varus or bordedine equinus or in an individual who is particularly heavy or active. Composite graphite tends to fracture quite easily. I think it has quite a way to go yet before it is as good as rohadur.
What properties should the "ideal" functional orthotic material have?
The material has to be somewhat flexible. But it also has to have a sufficient resistance to resist the abnormal forces that are created during the process of locomotion. Let's take an example of treating plantar calcaneal heel pain associated with mechanical heel spurs. Remember, I'm talking about pain from a mechanical spur, not caused by arthritis or other medical reason. When I was in practice I had one case that took about six months before the pain resolved; all the other cases resolved within one month or less. I never needed to resort to surgery during the entire time I was in practice to treat heel pain.
I was able to differentiate mechanical from other etiologies just by the break in the Cyma line. But the critical thing was that we had a rohadur at that time that was a little more flexible than the rohadur commonly in use today. We didn't realize the significance of that until it was discovered that some component used in the fabrication of rohadur was carcinogenic. As a result, the material was changed and the newer rohadur was a little bit darker and also a little more rigid.
When this new, more rigid mateial came out, doctors who had been using the earlier rohadur successfully began reporting a ten to fifteen percent failure rate in treating mechanical spurs. Then surgery was needed. And these are the very people who were getting the same excellent results that I did when I was in practice. So I would say as far as flexibility is concerned, the amount of flodbility in the old rohadur would be just about ideal. On the other hand, the old rohadur broke much more readily than the new one and also changed its shape within a period of one or two years with a person who had a major foot problem. The new rohadur can last as long as fifteen years, even in major foot problems.
How do you feel about the use of soft orthosys to control biomechanical imbalances?
I don't believe you can control them.
Under what conditions and for what problems do you advocate surgical intervention?
When we can't solve the problem short of surgery. For years people have thought that I was against surgery. I'm a strong advocate of surgery - but only surgery that is well indicated. I believe that research in surgery has a long way to go and its basis is biomechanics.
Do you contend that you can always solve the problem short of surgery?
No, not at all. My statement is that if you perform surgery without doing anything about the cause, the symptoms are going to recur in time and, therefore, you're doing the same thing the pediatrist used to do when he took the corn or callous off and had the patient come back once a month. The only difference is it's a little more sophisticated - they last three or five years before they come back for another surgery. Now, the difference is that when a doctor controls the function of a foot anci performs surgery, then he should have a long-term result as long as he can control function because he has eliminated the etiology of the problem. He can expect twenty to twenty-five years or longer with regard to his result.
Podiatry Today Cover, 1989.
What treatment protocol do you recommend to the podiatrist who sees a patient who has never been treated before and presents with moderately advanced subluxations and deformities of a fixed variety?
Take hallux valgus as an example. If the first IM angle exceeds 12o° you cannot reverse it with orthosis. You may relieve the symptoms, but you're not going to reverse the bunion deformity or the hallux valgus deformity. So this is definitely a patient that requires surgery. However, before I perform surgery on a patient like that, there are two things I want to do:
- first determine that I can control function;
- wait for the inflammation in thc first MP joint to subside.
I feel that a non-inflamed articulation is a better surgical candidate than an inflamed one. I found that I had less postoperative spasms and complications later.
Okay, so you prepared the foot beforehand. Would you define forefoot supinatus and compare it to forefoot varus?
Forefoot supinatus is a fixed position of supination of the forefoot about the longitudinal axis of the midtarsal joint. In other word, if the foot has a normal range of motion in the forefoot, the forefoot can invert relative to the rear foot and actually supinates. It moves in three planes, but the primary motion that you see is inversion. And so, if it moved into that position and became fixed by soft tissue, we would see an inverted forefoot that would look like a forefoot varus. If a foot has been functioning in a pronated position for many years, the forefoot is in an inverted position all the time and becomes somewhat fixed in that position. A forefoot varus is a structural deformity of the foot in which the forefoot is fixed in an inverted position because of a structural abnormality some place within the midtarsal joint. We don't know what a forefoot varus is. I see clinically what I believe to be three different types of forefoot varus conditions. But it's purely surmised at the present time because we haven't had the opportunity to study this on freshly amputated specimens the way we should.
Some controversy exists about whether there is such a thing as a forefoot valgus. Can you clafify that?
Theres no question in my mind that there is forefoot valgus, but people tend to confuse forefoot valgus with a congenital plantar flexed first ray. In other words, the forefoot can be everted because of a midtarsal joint deformity or it can be everted because the first my is plantar flexed. Even when the second ray is plantar flexed, an everted forefoot deformity is produced. When the first ray is congenitally plantar flexed, then you see a major degree of forefoot eversion. When it's an acquired plantar flexed deformity, then it's a very minimal forefoot eversion. But I've seen a three-month-old child who had a 35° everted forefoot deformity that was caused by a planter flexed first ray. It was so great that it couldn't be reduced completely by surgery. The child will require several surgeries during the course of its lifetime to correct that degree of deformity.
The maximum degree of everted forefoot deformity, particularly forefoot valgus, that I have succesfully treated with orthoses has been 21°. Beyond that you start getting into difficulty because of the lack of space within the shoe.
Is there such a thing as a true posterior cavus deformity, or is this observed only as a compensation for anterior cavus?
I dont like the term cavus. A cavus just means a high-arch foot - whether it's high in the back or in the front. What came first - the chicken or the egg? If we have a plantar flexed deformity of the forefoot, that means a whole forefoot is lower than the rear foot. If you put that foot on the floor the rear foot is going to become elevated, isnt it?
Sounds logical.
And so, what's to say that it's a forefoot or anterior cavus or a rear cavus? In other words, what we have to do is describe the joint at which the deformity occurs and the direction of that deformity. So I can't even get into a discussion on something that I don't understand.
Typically, chronic ankle sprains are due to a rear foot varus. Yet foot surgeons presently tend to use the peroneus brevis tendon, which we know is the best pronator of the foot, in the surgical repair. Doesn't that worsen the pre-existing inverted position?
I disagree with muscle transplants for structural problems that can be treated with orthoses. If you have a rear foot varus that is laterally unstable you can use a very high lateral heel cup and a lateral flare on the rear foot post and control it quite adequately for a basketball player or runner or even a person who's just walking. It is unnecessary to resort to surgery. In fact, I think that is indiscriminate surgery.
Would you consider it indiscriminate to surgically correct chronic latelal ankle instability?
Yes. A patient with a severely plantar flexed first ray deformity for which a subtalar joint fusion was performed was referred to me. The talus had come completely out of the ankle mortise. Ankle surgery had been recommended for him. Let's think about it: the plantar flexed first ray inverts the rear foot when the midtarsal joint can't invert any further. The rear foot tends to supinate at the subtalar joint and invert, putting an inversion force into the ankle joint. When the doctors decided they wanted to treat this individual to straighten up his heel, they did a triple arthrodesis on him, But they didn't do anything about the planar flexed first ray. As a result, the inverted force was referred to the ankle and the joint subluxed. So now they were talking about arthrodesing the ankle joint. If they had done that, the next thing to go would be the knee and then the hip. Instead, we put an orthosis on the individual that supported the everted forefoot and actually reduced the subluxation of the ankle. We succeeded in moving the talus back into the ankle mortise and we recommended that he have planar flexed first ray surgery. It has been fifteen years and he hasn't agreed to it because he is getting along so well. This is what I mean about people performing surgery when they don't understand pathology.
Joint implants have not been particularly effective or, at least, they haven't lived up to their expectations. From a biomechanical perspective, why is this?
I don t think people are controlling pronation, so the forces that are causing the stress on the implant are still present.
If you wanted to design a total first metatarsal phalangeal joint implant, could you do anything to boost its longevity from a biomechanical stress aspect?
Not with regard to designing the implant.
With the functional approach?
With the functional approach, the result will be much better.
Interview: Back to the Root
If you adopted just the functional approach, would the implant be needed?
Without the implant, say we performed the Keller bunionectomy, it might take a year or more before that Keller became functional. When we used implants fifteen or more years ago (before implants were as sophisticated as they are now) and an orthosis afterward, we found the hallux might become functional again and actuaily bear weight in as little as three months. So from the standpoint of function, there was an advantage.
lf a patient has an extremely painful pathologic sesamoid bone, would you recommend its removal?
If it's the bone that's causing the pain, yes.
So that's a trick answer to my trick question, right?
Yes.
You have given a lot to your profession in terms of collating, documenting, researching, proving, writing - creating a body of knowledge that didn't exist in one place before. You made your theories and your proposals public. Why?
It was because of my frustration in trying to teach and finding that I was very ineffective as a teacher. So I began to try to put it into literature, hoping that it would increase the number of people who became knowledgeable. I still find, however that the most knowledgeable people I know in the field of biomechanics are those who are working with our laboratory where we have the chance to meet with them once a year. According to them and anyone else who's attended, it's supposed to be the best seminar in the United States every vear because everybody participates. And if anyone has anything to suggest or disagrees with us, we get into some royal battles. It's fun.
Do you win?
Sometimes.
Thank you, Dr.Root.