10 25-2013 report - orthotics and technology

1. Orthotics and the Technology Behind It
No technology is actually “bad” per se. Information derived from technology tells us
something. The “something” that we learn however, may or may not accurately, and
reliably, describe what we really need to know.
As unpopular as it might be to mention “the elephant in the middle of the room”, some
companies in the foot orthotic industry use creative wording to overstate “their”
technology capabilities regarding foot orthotic fabrication. Plantar pressure and photo
data are examples of good technologies, misused to create the illusion of providing
important information.
Tekscan (www.tekscan.com) and EMED (www.novel.de) manufacture the most popular
pressure analysis systems for the purposes of research, plantar pressure screening and
pressure distribution evaluation. Despite dozens of independent accuracy and reliability
studies, outcomes have been variable. To date, pressure data is not used with complete
confidence in a research environment where attention to reliability and accuracy are
much more rigorous than in a clinical setting.
Clinically, pressure mapping may have utility in conjunction with a proper physical
assessment in the “at risk” populations such as diabetes and rheumatoid arthritis but
not for the purpose of custom orthotic fabrication. For research, multiple steps in a
controlled environment are required and systems are calibrated regularly by comparison
with a standard. These steps are rarely undertaken in a clinical setting due to time and
cost considerations. Lastly and most importantly, measurements of plantar surface area
and pressure cannot provide accurate information in the vertical dimension, therefore
cannot capture the physical anatomy of the foot.
True custom-made foot orthoses are fabricated from a volumetric (3-dimensional)
model of the patient’s foot that duplicates the unique plantar anatomy over which raw
materials are vacu-formed to create the orthosis. Casting methods for obtaining an
anatomical model include direct plaster or foam impressions, 3-D laser scanners and
stereophotogrammetry (digital images taken from multiple angles).
In order to qualify as truly custom-made, each orthotic must control the passage of
weight through the foot based on body mass, medial arch characteristics and forefootto-rearfoot flexibility indices. Each orthosis must be uniquely fabricated for each foot
because left and right feet can differ within the same person. There are an infinite
number of combinations of arch height, body mass, flexibility and side-to-side
differences within the population.
“Custom-made” is not the same as “customized”. Unfortunately, many clinicians rely
exclusively on a pressure plate and photo scanner systems to “diagnose” for them. In
reality, the only “diagnosis” resulting from a patient walking across a pressure plate or

2. standing on a photo scanner is which pre-manufactured orthotic model their
laboratory’s computer should select for their patient.
Many customized and prefabricated foot orthoses use an “extrapolated” model of the
patient’s foot in the manufacturing process. Examples of these techniques are pressure
plate mats and photographs or ink imprints which use pressure and light data to select
an approximate foot model.
Laboratories using these technologies often rely on a library of pre-manufactured shells,
molds and/or digitally stored foot shapes to create the customized orthoses.
A: Custom-made
The custom-made orthosis (A) was cast to capture the foot as it might optimally
function with the heel and forefoot on the ground with the maximal amount of medial
longitudinal height available without artificially inverting the midfoot. The orthotic shell
was individually calibrated to flex slightly as weight is transferred over the medial arch.
B: Pressure Plate
The pressure mat company (B) used a “best-fit” computer-modeling program to match
an insert from a library of pre-manufactured shells to the patient’s force plate data. The
flexible plastic is deformable under much less load than the patient’s body weight.
The third company (C) used a colorized photocopy of the patient’s foot to locate
anatomical landmarks in order to glue prefabricated components (metatarsal pads, heel
wedges and arch pads) to a leather base.
C: Light Data (AKA: foot photocopy)
This mini-study serves to show the visual difference between an orthotic manufactured
from an anatomically correct cast versus pressure / light technology’s estimate about
the anatomy of the foot.
As previously discussed in Part I, there are only a few scientifically conducted
comparisons between prefabricated foot orthoses and custom-made orthoses in order
to make definitive statements about efficacy (11-13) but common sense might suggest
that a true representation of the foot in a necessary starting point.
Not only is it the responsibility of practitioners to perform due diligence on their orthotic
laboratory to understand how any related technology assists (or not) in the orthotic
fabrication but most practitioners want to understand the differences between a
custom-made device and a prefabricated or customized device in order to provide the
best possible care for their patients.

3. Ask questions, request written details and go for a tour of your laboratory. You have
the right to know the facts about what you are selling the public.
In review:
• Pressure data can assist in formulating a diagnosis and a treatment plan for “at risk”
patients but it alone will not result in a custom-made orthosis.
• Not all orthotic laboratories provide true custom-made orthoses. Through creative
marketing, it can be hard to discriminate facts from semantics.
• There is no secret process to fabricating an orthotic. If your laboratory can’t (or
won’t) allow you to review their manufacturing procedure, this is a cause for concern.
• Most insurance policies state that foot orthoses must be custom-made. The current
working definition of custom-made requires a 3-dimensional cast of the foot and the
use of raw materials formed over the cast.
• Practitioners have a fiduciary responsibility to their patients to ensure that they are
getting what they paid for. If you provide an invoice stating that the orthoses are
custom-made, you must ensure that they are custom-made according to the industry
definition.
• Practice what you know, and know what you practice.
Visit www.theorthoticexpert.com for more information about Orthoses and
Foot Doctors in Ancaster, Ontario CA. If you need an Ancaster Orthotic Expert
in Ontario CA, visit www.FootKneeBack.com
Other articles you will find interesting:
What is the Evidence for Using Foot Orthoses
The Evolution of Kinesiology Tape