Insights On The Evolving Nature Of Orthotic Education And Casting
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.
Do over-ground weightbearing scanners have any place or value in producing custom foot orthoses that have efficacy in clinical practice?
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.