Some of the design changes described in the literature include the following:

Deep heel cups. To this very day, many practicing physicians believe that a deep heel cup is necessary to create optimal function of a foot control device prescription or otherwise. Clinically, no consistent measurable benefit is observed, even with the deepest of heel cups. This is supported in the patent literature where most describe the heel region of their device as “Cupola” in shaped. Functioning like a ball and socket, this part of the device corresponding with the heel of the foot will spin or rotate no matter how pronounced the cup design. Other than helping the shoe hold the foot directly on top of the wedge portion of a support device, a deep heel cup has little to do with overall function.

Lateral Flange: This elevation of the outside of a device is a design which has not been very popular with podiatric physicians. Even though it also helps the shoe hold the foot on the highest part of the wedge portion of the device, it is not all that effective. Also, according to most patent authors, if the shoe is wide and lets the foot slide over the top of this design, it often digs into the tissue, which creates pressure and provides no obvious benefit to foot function.

Medial Flange Most physicians who treat patients with prescription orthotics recognize that the benefit of treatment with an orthotic device is related to the height of the wedge. This logical belief that a higher wedge would help more has caused many to try a design characteristic know as a “high medial flange”. When you look at a finished prescription orthotic with a “high medial flange”, it looks like the wedge is very high. Unfortunately, when the device is used in most patients, it provides no additional help, causes irritation to the inside of the arch, and takes up more space that requires a larger shoe. 

Understanding this “increased wedge” medial flange dilemma was a requirement before Theta could be defined and quantified accurately. Most clinicians now acknowledge that medial flange design has little if any ability to stop pronation. Theta research defines the part of the wedge described as the “medial flange” as outside of the points defined by Theta. Our research also explains why the medial flange design does not help.

Intrinsic and Extrinsic posts are basically plastic shims that are applied in a way to stabilize the device in a MORE wedged position.  Conceptually, this increases the wedge that corresponds with the medial longitudinal arch and does in fact provide more wedge with more support and less collapse of the arches. Prescription orthotics produced by many current orthotic laboratories use these techniques to alter the wedge from what the cast impression actually shows. None of these labs quantify the angle of their device before or after the wedged post is placed. No other labs aside from Theta have quantified the part of their device that changes foot function.

This is a photo of a rhoadur plastic orthotic; heat contoured to a positive mold of a human foot. The contoured plate is then tilted additionally with an intrinsic varus post of 20 degrees in the forefoot, and with a 20 degree varus extrinsic acrylic post in the rearfoot. It is representative of the technique we used to fabricate our orthotics during the first 8 years of our basic research.