Acknowledging changes in the way podiatry students learn orthotic therapy, these experts discuss how such changes affect the quality of casting, and how young practitioners can gain casting experience. They also discuss common questions from prescribing podiatrists and debate the value of over-ground weightbearing scanners.
Noting that while he does not own a laboratory or have financial connections with any laboratory, Robert D. Phillips, DPM, says he does notice that young practitioners have little idea of casting theory. As he says, the only textbook to deal with orthotic casting has been out of print for many years.
As a result, fewer and fewer practitioners can explain Root casting theory, how it developed and how it facilitates normal foot function, according to Dr. Phillips. He says some practitioners have adopted the idea that DPMs are creating an arch support, a model of what the foot is supposed to look like, and if one props the orthotic into this position for a while, after removing the prop, the foot will continue to look the same.
“The decline in teaching foot orthotic/biomechanical theory in both the classroom and clinic has degraded not only the quality of the casts but also the understanding and expectations of the practitioner,” claims Christopher Smith, DPM.
Since many practitioners lack experience with negative casting, Dr. Smith feels they may simply defer the casting procedures to office assistants or CPeds. He says this reflects a “gross indifference” to casting, which he says requires both art and science.
“At best, this is simple dilution of knowledge and skill, somewhat motivated by office economics but more importantly, it reflects a failure of the profession at large to appreciate the significance of a good cast of the foot,” asserts Dr. Smith.
Paul Scherer, DPM, has not seen a decline in quality negative casts or scans at ProLab Orthotics but notes his orthotic lab only accepts non-weightbearing plaster or fiberglass casts or scans that capture the posterior surface of the calcaneus and a forefoot to rearfoot relationship. However, he does note seeing a large increase in new clients, particularly from the East Coast, who want to send crush boxes for functional orthotics, which the company declines.
“It is obvious that these practitioners do not understand the concept of how orthotics are intended to prevent subtalar or midtarsal joint compensation to decrease tissue stress,” says Dr. Scherer. “I believe their instructors or orthotic manufacturers may have told them that a proper functional device can be made from an impression of the foot in a pathologic position. I do not believe this is possible.”
In exhibit halls, Dr. Scherer has heard manufacturers telling practitioners that a lab can make a proper three-dimensional functional device from a two-dimensional pressure mat or scan. He says this idea is just as much an illusion as the technique of touching the full plantar aspect of a foot to the glass plate of a foot scanner. He feels it’s not the schools that are teaching this concept but rather that practitioners have succumbed to “the nonsense perpetrated by financial opportunists and amateurs who work outside of academia.”
Dr. Phillips acknowledges a rise in the number of individuals who are determined to return to the pre-Root era of arch supports. He says this leaves young professionals confused by a number of competing theories on biomechanics and teachers (especially at the post-graduate level) who do not want to be bothered trying to sort out fact from fiction.
“I believe the problem goes much deeper into the profession, though, and underscores many problems that continue to haunt the entire gamut of biomechanical knowledge and practice,” says Dr. Phillips. Those problems include:
A change at the entrance level of podiatry school by discarding the podiatry school admission test and adopting the MCAT. While Dr. Phillips says this certainly makes sense in terms of making it easier for medical college applicants to also apply to podiatry schools, it has the disadvantage of sending a message to applicants that they do not have to have basic 3D visualization skills, which are of paramount importance in understanding biomechanics.
The struggle for podiatry to become recognized as a true medical specialty has increased the number of hours spent in general medical studies, often at the expense of biomechanics training. Despite this, Dr. Phillips notes the schools still continue to train students in surgery as if new graduates are going to practice surgery before entering residency training. Residency interviews concentrate on how many bunion surgeries the prospective resident already knows, not on the mechanisms that lead to bunions, which he calls “totally backward.” He argues that the standard pat answer that bunions form because of first ray hypermobility “is at best a very superficial answer.”
Dr. Phillips notes that applicants for residency programs are required to discuss flatfoot surgeries without any idea of all the various types of flat feet, which flat feet are normal and which are abnormal, and how to examine an excessively pronated foot. In addition, he says applicants for residency programs must enumerate a number of joint destruction surgeries without any discussion of what changes to expect after surgery on the function of the foot and other parts of the body. Even with the upgraded CPME 320 residency requirements, Dr. Phillips says the minimum activity volume for the number of surgeries is more than five times the number of biomechanical examinations, which he calls “exactly the reverse of the real practice of podiatry.”
Failure of schools to actively recruit the brightest biomechanical minds for teaching. Dr. Phillips acknowledges that there are “extremely dedicated people” teaching biomechanics at the schools but there are far too few of them. He says few if any funds are dedicated to biomechanics research at the schools and faculty are not well rewarded for producing strong biomechanics research.
The publication in recent years of a number of biomechanics research papers that claim to discredit Root biomechanical theory. Dr. Phillips says although such papers surface in reputable journals, podiatrists rarely write them. Recently, he personally contacted a number of authors of orthotic efficacy papers regarding the reasons they selected their particular orthotic materials for research.
“I shouldn’t have been too surprised to find that none had any idea about the properties of the materials they chose,” says Dr. Phillips of the study authors. “As a result, in almost all research, all orthotics are considered to be equivalent, regardless of foot type, orthotic casting technique or orthotic shape, orthotic prescription variables and orthotic materials. With equivalency of all orthotics, then, straw man arguments are set up as to whether Root theory is correct or incorrect.”
Failure to further research and teach midtarsal joint function. Although the orthotic cast’s most important function is capturing the forefoot to rearfoot relationship, Dr. Phillips says physicians spend little time researching and teaching how that relationship changes when the subtalar joint pronates and supinates. He says the profession continues to teach only to the level of understanding that the foot is either a mobile adapter or a rigid lever. Yet if one asks any student what type of lever the foot is, he says almost none can tell you whether it is a class 1, 2 or 3 lever.
Furthermore, Dr. Phillips notes if one asks students to explain how any surgery changes the leverage effects of the foot, “you will get a blank stare.” He notes a few instructors have tried to introduce to the profession the clinical identification of the subtalar joint axis, an identification that he totally supports. “Yet even these brilliant minds are focusing on the foot as if the foot were a solid block of wood between the subtalar and the metatarsophalangeal joints,” says Dr. Phillips.
As Dr. Phillips recalls, he had a great difficulty in learning orthotic casting instruction when he was a student. When a group of students from his graduating class of 1979 felt frustrated that they weren’t learning casting well, he recalls making an appointment with Merton Root, DPM, where they spent four hours with the master caster himself, learning his technique. He specifically remembers spending half the time learning to position the patient properly, saying without proper patient positioning and the proper physician posture, it would be impossible to make a good cast. After graduation and taking specific biomechanics clinics in which he built the orthotics himself, Dr. Phillips recalls having much to learn. In those days, he notes a great many practitioners still made their own orthotics in their offices or in little laboratories they built in their garages.
“I want to say that if you really want to learn orthotic practice concepts, do your own casting and build the orthotics yourself,” says Dr. Phillips. “By doing so, you really do find what works and what does not. I have had few, if any, patients refuse to wear orthotics because they were not perfectly polished. In fact, when I was in private practice, I could tell if a person was wearing his or her orthotics by how well his or her socks were polishing the plastic.”
Dr. Phillips recalls using the Root Lab for a few orthotics and says Dr. Root would do an annual seminar free of charge for anyone who used his laboratory. These seminars never offered any CME credits but he says they were invaluable in learning what was working for others as well.
“It was truly one-on-one teaching that is almost impossible to find anywhere today,” he says. “I have been the beneficiary of a person who built a small orthotic lab dedicated mostly to making the profession better and only secondarily to making a profit.”
Dr. Smith says the skills to cast a foot with the subtalar joint neutral and the midtarsal joint locked are difficult because this procedure is both a science and an art that requires skilled professional guidance. With practice, he notes one can obtain positional skills but maintaining that alignment while the plaster cures is an additional challenge. As the practitioner fatigues, the foot drifts into a supinated position, which he believes is the most significant cause of orthotic discomfort and failure.
However, Dr. Smith notes the new digitizers and scanners “offer a great hope” for that problem because maintaining proper foot position/alignment requires minimal time, ranging from an instantaneous flash to an approximately 15-second scan.
There is minimal formal post-graduate biomechanical learning because very few seminars include appropriate lectures, even at state seminars officially sanctioned by the American Podiatric Medical Association, according to Dr. Smith.
Dr. Phillips notes his alma mater was able to only do so much in regard to biomechanics education. He says the dedication of the aforementioned orthotic laboratory improved the orthotic prescribing practices of those in the profession. Although the Prescription Foot Orthotic Laboratory Association (PFOLA) was supposed to bring the same dedication to the entire profession, he notes this has failed to materialize in the last few years. Part of the problem, says Dr. Phillips, is that it is difficult to learn biomechanical principles and practices in large lecture halls. He suggests that podiatrists can best learn this in small groups.
Dr. Phillips also cites the influence of his father, a podiatrist who was interested in biomechanics, and who noted that it was not unusual for practitioners who wanted to learn biomechanics to visit and work with other practitioners who were considered more expert in this arena. If he were a young doctor today, he would contact known experts who are seeing 10 or more orthotic patients per day, and watch and assist in their offices. Although there is no CPT code to bill for such time and many people may not want to teach because they may feel slowed down, Dr. Phillips argues this is the only model that seems to have worked well in the past.
For Dr. Scherer, the most common orthotic prescribing questions, from clients or students, fall into eight categories or pathologies. These are adult-acquired flatfoot, plantar fasciitis (with and without an everted heel), functional hallux limitus, pediatric flexible flatfoot, pes cavus, metatarsalgia, tarsal tunnel syndrome and medial knee pain. He notes most reputable orthotic laboratories produce a specific orthotic designed for each pathology rather than a generic device that is designed for the age, shoe or activity of the patient.
Colleagues are often frustrated by trying to understand why the orthotics they order are not alleviating symptoms, notes Dr. Phillips. He finds one of the most common problems is that practitioners do not perform basic biomechanical examinations. These podiatrists learned that the symptom is supposed to respond to orthotics yet he notes when you question them about the specifics of their patient, these physicians lack any information about the basic biomechanical examination. In fact, Dr. Phillips notes many practitioners prescribed these orthotics without doing any type of biomechanical examination.
Many years ago, a residency director told Dr. Phillips that he could write the book “Everything You Need to Know in Biomechanics” with one sentence: “Take a neutral cast.”
“I laughed at the time because I thought he was making a joke but I now find that a great many practitioners believe this is true,” says Dr. Phillips. As a result, he notes that many practitioners (or their staff members) take a cast and send it to the laboratory, expecting the laboratory to figure out how to make the orthotic. If the orthotic comes back and does not work right away, then these practitioners believe it must be the laboratory’s fault or it must mean that orthotics cannot work for the patient and some other type of therapy is necessary, notes Dr. Phillips.
Dr. Smith most frequently hears questions about the appropriate flexibility or rigidity for a patient of a given weight with little consideration for activity, foot gear, sport or a specific foot type, all of which are pertinent factors to the flex of the orthotic. Oddly, he says some are apprehensive of the more rigid flexing devices because they equate softness with comfort and equate rigidity with discomfort. As Dr. Smith explains, rigid orthoses help realign the foot and the immediate suprastructure, and these positional changes are not possible with pliant foot devices. Pain relief is primarily a direct or indirect function of improved alignment and function, according to Dr. Smith.
A few years ago, Dr. Phillips recalls a notable orthotic lab owner asked an audience, “Are you providing your patients custom orthotics or are you providing them prescription orthotics?” He then went on to explain that the laboratory controls a custom orthotic but the physician controls a prescription orthotic. Dr. Phillips does not put all the onus on the lab. He says the physician is responsible for examining the patient and for fitting and following up with the patient’s orthotic therapy. Indeed, there are so many things that the orthotic lab can never know about the patient or the foot, and only the physician can have this knowledge through physical interaction with the patient, maintains Dr. Phillips.
Dr. Phillips also cautions remembering that the number of variables one can change in an orthotic are almost too numerous to count. It is not uncommon for him to make several orthotic adjustments before finding that perfect combination of variables to make the orthotic function and feel great.
Dr. Smith notes that Root’s description for the negative cast of the foot dictated that the subtalar joint is neutral and the midtarsal joint locked (forefoot everted on the rearfoot). Although some have challenged Root’s tenets, Dr. Smith says his description for neutral position casting remains “the constant gold standard for both negative casting and digitizing/scanning techniques.”
With weightbearing techniques of a collapsed foot, Dr. Smith says it is possible to place the subtalar joint in neutral position but it is impossible to lock the midtarsal joint at the long axis (inversion/eversion axis). With weightbearing techniques, he notes the first ray is elevated and therefore subject directly to bunion formation. Weightbearing casting/scanning/digitizing techniques of the foot make very good arch supports but do not meet the criteria for a Root functional orthotic, according to Dr. Smith.
Estimating that there are over 100 published studies on the efficacy of custom orthoses for reducing the symptoms of foot pathology, Dr. Scherer does not know of even one study published in a peer-reviewed journal that evaluates orthotics made from weightbearing scans.
“You would think that if this were effective in producing a proper orthotic, Walgreens, CVS or Dr. Scholl’s would have funded the research and published the results,” points out Dr. Scherer.
Dr. Phillips believes scanners that provide information about what goes on inside the shoe are definitely valuable in determining how the orthotic/shoe is functioning. He says an optimal situation for evaluation of orthotic function is a combination of video and in-shoe pressure evaluation. The in-shoe evaluation is especially important for diabetic orthotics, according to Dr. Phillips, as it determines whether the orthotics are offloading high risk areas that they are designed to offload. In using a pedobarograph, he has found that a great majority of the diabetic orthotics physicians design “are doing much less than we believe they are doing.”
This has led Dr. Phillips to rethink many of the old adages and beliefs about how to offload high pressure in the foot. He would say that for any practitioner wanting to treat the high-risk diabetic foot, pedobarograph studies are essential in documenting the results of their work. On the other hand, Dr. Phillips ascribes much less clinical value to pedobarograph studies in which the patient walks barefoot. He says they may be helpful in assessing the results of a surgery designed to modify pressure without any shoe intervention but otherwise offer little value.
As for the ability of a pedobarograph to dictate what the shape of the orthotic should be, Dr. Phillips says there is absolutely no literature to support the possibility. Most systems that claim that they can do this are “black box” proprietary systems, he notes. For the most part, Dr. Phillips says such pedobarographs provide nice pictures that impress the viewers but the users rarely ask the question as to how the actual transformation from pressure data to shape data occurs. If practitioners do ask, he says they learn that it is proprietary information. Saying he believes in prescription orthotics, Dr. Phillips says he will not turn over the responsibility of the prescription to a black box system that he does not know everything about.
Dr. Phillips is affiliated with the Orlando Veterans Affairs Medical Center in Orlando, Fla., and is a Professor of Podiatric Medicine at the College of Medicine at the University of Central Florida. All opinions he expresses are his own and in no way should be construed as representing the opinion of the U.S. government or any of its agencies.
Dr. Scherer is a Clinical Professor at the College of Podiatric Medicine at the Western University School of Podiatric Medicine. He is also the CEO of ProLab Orthotics/USA.
Dr. Smith is the Vice President of Northwest Podiatric Laboratory and is a Professor Emeritus at the California College of Podiatric Medicine at Samuel Merritt University.
Dr. Richie is an Adjunct Associate Professor within the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University in Oakland, Calif. He is a Fellow and Past President of the American Academy of Podiatric Sports Medicine. Dr. Richie is a Fellow of the American College of Foot and Ankle Surgeons. He is in private practice in Seal Beach, Calif. Dr. Richie writes a monthly blog for Podiatry Today. One can access his blog at www.podiatrytoday.com/blogs/301  .
For related articles, see the November 2011 DPM Blog, “What Happened To Continuing Education For Podiatric Biomechanics?,” by Doug Richie, Jr., DPM, FACFAS at http://tinyurl.com/phfawo7  and the article “Orthotics Are Not Biomechanics” in the December 2012 issue of Podiatry Today. For other articles, visit the archives at www.podiatrytoday.com  .