Biomechanics for Technicians

When I started out as an orthotic technician more than 25 years ago, I was taught to always flatten the plantar surface of an AFO mold. Then I had the opportunity to work with a group of physical therapy students. I felt secure in talking with the students about my techniques because I thought I was applying the best we had to offer to rehabilitation science.

The students toured the lab and remarked that we were doing some amazing stuff, until they saw how we were modifying our molds. One of the students asked, "Why do you flatten the bottom of the foot when you modify the mold?" I answered that we were building mechanical devices, and the flat surface was our foundation. Wasn't it?

After that, I started to question my fundamental beliefs about how to build a quality device. I was fortunate to have spent my first few years as a technician with some visionary orthotists, and what they taught me made sense. I started to wonder if we were overlooking an important part in the process, the part where modifications are made so that a device becomes an extension of the patient. When we make arch supports, for example, we never flatten the plantar surface. On the contrary, arch supports mirror the plantar surface. So what's the difference between making an arch support and an AFO? Why is it that an arch support should take advantage of the curvatures of the plantar surface, and the bottom of an AFO or other orthosis should be flat?

Not long after my encounter with the physical therapy student, I had the opportunity to work with another physical therapist and author who was teaching a class on neuro-developmental treatment (NDT). She needed a volunteer to fabricate an AFO for a test subject. Our lab was offered, and as I worked with this physical therapist, she helped me understand the intricacies of the foot: its bones, nerves, tendons, and vascular structures, and how each of these components has its own set of needs.

After working with her, I was convinced that technicians must see the foot, not the floor, as the foundation of an orthosis! I knew I had to learn more about pedorthics, tone inhibition, and neuro-developmental techniques if I wanted to create biomechanical devices—devices that fit properly—as well as to focus on the specific pathology without causing any collateral damage.

This level of knowledge is beyond the standard education for technicians, but if I am modifying a mold, it's my responsibility to know about physiology, neurology, and pressure mapping. Every patient who needs a brace has a pathology. Seldom are those pathologies purely orthopedic; there are typically underlying vascular or neuropathic disorders as well. There is no orthopedic solution for a neurological problem.

Technicians need to be aware of this when building a device, and practitioners need to be aware of this when taking a cast. If the cast is taken weight-bearing, on a flat surface, much of the plantar data disappears. When a cast can be taken on a foam block, semi-weight-bearing, or even hand-manipulated, that cast takes on a whole new level of function. The surfaces of the foot become much more natural, and the load pressures can be more accurately distributed. Neurological inputs can be reduced, deep-tissue weight-bearing techniques can be utilized, and the brace can better fit the patient. The device created from a flat-bottom mold can cause collateral damage by creating excessive pressure on at-risk tissue, exacerbating existing problems, and putting the surrounding tissues at risk.

I've worked with many practitioners to help them change their casting technique for these devices, and by doing so, they are seeing better results with their patients.

I believe a technician's role is to understand and interpret the orthotist's vision for the patient and make that vision a reality. I also believe the practitioner and technician should work as a team to make a device that will assist the patient in the best manner possible. If I don't understand the nerve structures on the foot, then it's probable that I won't make a properly functioning device. Orthoses are not assembly-line widgets; they are custom-made biomechanical devices that help improve the quality of life for the people who use them.

Tony Wickman, RTPO, is the CEO of Freedom Fabrication, Havana, Florida. He can be reached at