How The ACFAOM Lectures Cured A Phobia Of Biomechanics

Kathleen Satterfield DPM FACFAOM

Do you have a biomechanics phobia? Many of us do and until recently I did not know there was a cure.

I attended an elegant little meeting last month in Florida that surprised me. I intended to take home ready-to-use ideas about wound care especially and I did. Surprisingly though, I ended up attending most of the biomechanics sessions and bragging to friends about everything that I had learned. You see, I am no biomechanical guru. In fact, it is quite the opposite. The subject usually gives me psychological hives although I have long advocated the importance of biomechanics.

I became excited about the subject at the recent American College of Foot and Ankle Orthopedics and Medicine (ACFAOM) Clinical Conference. The speakers took the physics off the page and away from the goniometer, and into the hands of people like the big, enthusiastic, motorcycle-riding Mark Reeves, DPM. His equally excited compatriots — Larry Huppin, DPM, Doug Richie Jr., DPM, and Paul Scherer, DPM — gave the audience news that they could use, which was probably why the audience grew throughout the day rather than dwindled. That is something I have not experienced at many meetings.

A friend who arrived to the meeting late that evening, hearing of my surprise about the biomechanics section, asked me to give her one thing I had learned. I gave her two things I learned.

1. If you are still casting orthotics with plaster, you are doing it the really hard way. There are now free standing scanners that are fast, effective and accurate. They allow you to position the foot in a neutral position and recapture your costs quickly. Another important factor is that the labs affiliated with the technology are sufficient enough to handle a significant amount of business as the technology becomes more popular.

2. If you have long distance runners in your practice, you have probably been frustrated with the treatment of shin splints. One physician demonstrated a method of injecting Marcaine and cortisone below the fascia of patients who experienced performance limiting shin splits. You would perform the injection about two weeks prior to the runner’s next performance, allowing him or her to literally get back into the race.

As a disclaimer, I am an officer of ACFAOM and presented at this conference myself. As anyone who knows me is aware, I have always had a fear of biomechanics. For a group of lecturers to make this difficult subject not only understandable but fun — well, that is truly an achievement.

Kudos to all of the lecturers in that track.


Nicely put Kathleen, and thanks for being 'open' with your views on biomechanics. Technology is helping us do things a lot more speedier, and it sure impresses patients too!

Larry, I can't recall now the specific scanners that were recommended for capturing patients' feet for this replacement to the old plaster casting method. Can you fill me in on this? One of my students was asking for the information and I had to plead "age"! Thanks!

Hi Kathleen. Here's the answer to your question. Your students are welcome to contact me if they have questions. Larry

We developed 9 criteria that the ideal 3D optical scanner should have to produce orthoses that provide optimum clinical outcomes and are an efficient option in a busy office.

1. Allows for standard neutral suspension cast technique. Although there is little evidence that a neutral suspension cast creates an orthosis that causes the foot to function in subtalar neutral position (and little evidence of the importance of this or even what that neutral position really is), the non-weightbearing suspension cast technique avoids the problems discussed earlier associated with semi-weightbearing and weightbearing casts, and allows for plantarflexion of the first ray.

2. Allows the foot to be held with no contact on the scanning unit. Pressure on the foot from the scanning unit deforms the plantar arch shape and has great potential to dorsiflex the first ray. An orthosis made from an image where the first ray is plantarflexed will act to prevent first ray plantarflexion and lead to functional hallux limitus

3. Captures plantar surface contours with plaster-like accuracy. Studies on orthotic therapy for metatarsalgia, hallux limitus, tarsal tunnel syndrome and plantar fasciitis indicate that total contact with the arch provides better clinical outcomes. In order to conform close to the arch, the image must accurately capture the arch.

4. Captures the posterior heel to allow frontal plane balancing. The ability to balance the forefoot to the rearfoot appears to offer better potential clinical outcomes in most of the primary pathologies commonly treated with functional foot orthoses. Balancing requires that the image of the posterior heel along with the plantar foot be captured in the image. Unfortunately, this critical aspect of the image is being ignored in many of the imaging devices currently being marketed.

5. Cost and time effective.
6. High degree of reliability.
7. Effective support and service infrastructure.
8. Intuitive software interface
9. Allows choice of multiple labs.

There are a number of companies with digital imagers on the market claiming to be able to produce an image from which a functional foot orthosis can be produced. Based on the best available evidence as to what kind of image can produce a FFO that provides optimum clinical outcomes, however, we were only able to find three units that created such an image. These are Sharp Shape, Veriscan and the iQube from Delcam.

Although all of these scanners work, we are recommending waiting to purchase a scanner until after the first of the year. There are significant changes coming to at least one of these scanners that will help decide which one is the best long-term investment.

Larry Huppin, DPM
Medical Director, ProLab Orthotics

A student stopped by my office this morning and asked if the scanners we were speaking of in this blog were the same ones that he had seen in stores, advertised by Dr. Scholl's. I had not considered that some people might think that there was a similarity here. Let me assure you there is no similarity. That should be clear after reading Dr. Huppin's excellent description of the device as well.

The "grocery store" variety of scanner is nothing more than a dressed up version of a Harris-Beath mat with a few bells and whistles (plus the bonus of a lot of previous customers' germs, possible blood from open ulcers, tinea pedis, and other lovely detritus. Makes you want to jump right on, doesn't it?) It is a two-dimensional view. These scanners of which we speak are definitely three-dimensional and capture what the plaster mold does but without the sticky mess.

Count me in on the modern technology. Can you imagine? No more expensive plumber's visits to unclog drains.

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