Pertinent Principles With Orthotic Therapy

Mindful of the evolution of orthotic therapy, this author provides guidance for fabricating effective orthoses, emphasizing sound casting principles and knowledge of orthotic materials.

“Comfortable and supportive” is the best way to describe how orthotic devices should feel. Although there are still some satisfied Rohadur patients out there, we are now using better materials with more options.

Just as materials have evolved, so has our biomechanical thinking. From obtaining foot impressions to fabrication to dispensing and fitting, there are many ways to provide biomechanical help to our patients. With our specialty becoming more surgically focused, we cannot afford to let go of our orthotic knowledge and roots. There are more tools available now than ever before that help us treat our patients conservatively and surgically. By focusing on orthotic therapy, both our non-surgical and surgical patients will have better outcomes.

Orthotic therapy starts with the foot position and impression technique. Whether you select plaster, foam, or non-weightbearing or semi-weightbearing scanning, the orthotic is only as good as the foot impression you obtain. A bad foot impression, even with excellent fabrication, will yield a poor result.

In addition, orthotic devices are only as good as the shoes patients wear. Heel height, toe break, shank stiffness and counter strength all have a direct impact on how the orthotic devices will feel and function. For instance, try wearing orthotic devices in flat or minimalist shoes versus traditional shoes with an 8- to 10-mm heel drop and you will notice a significant difference in the pressure in the arch region.

Key Insights On Fabrication And Orthotic Materials

After addressing these simple factors, the focus is then on the fabrication process itself. The typical negative cast/scan can turn into a positive model of the foot. On the positive scan, one can utilize numerous modifications in order to allow the foot to function with this device underneath it. Once one fabricates the devices, modifications are still possible but there is little room to make many significant changes without completely losing the contour of the device.

This is where material selection is important. Rigid and semi-rigid devices have their indications, but are often more challenging and time consuming to adjust. In those circumstances in which softer devices are possible, adjustments are faster, easier and very impactful. Materials such as ethylene vinyl acetate (EVA) can work extremely well because of its moldability, durability and adjustability.

An alternative approach to orthotic therapy is to make all posting available externally on the device itself so adjustments can be an ongoing process. This allows you to positively impact the device and its function very easily while the patient is in your office. Extrinsic posting and softer materials are key. The fact that the materials are soft does not mean you lose the control that more rigid materials provide. By providing total and intimate contact of the orthotic device and the foot spaces, the support can be even more significant yet at the same time offer more cushioning and comfort.

As time goes on and the devices become worn, it is very easy to make more modifications to maintain the control you are trying to achieve. Either by adding  material and/or grinding the posting in the direction needed, small modifications can make huge changes. For instance, consider the patient who feels like the foot is “rolling out” too much. Our rigid and semi-rigid devices offer little help in that regard, but extrinsically posting the entire orthotic offers better control from heel strike to propulsion.

For example, at heel strike, one can wedge the heel of the orthotic inverted, neutral or everted. In midstance, the clinician can address the arch posting and in propulsion, one can accommodate the forefoot with modifications that will aid first ray function and accommodate the metatarsal region.

In Conclusion

There will always be a place for the traditional semi-rigid and rigid orthotic devices. The key is to understand your patient’s biomechanical situation as well as possible prior to selecting the orthotic that will work best. This more hands-on approach is just another tool that can help you help your patients. All you need are some materials, glue, scissors and a grinder, and you will be well on your way to not only improving your orthotic outcomes, but providing immediate help to the patients in front of you right now.

Dr. Levine of the the Foot & Ankle Specialists of the Mid-Atlantic practices in Frederick, Md. He is also the director and owner of Physician’s Footwear, an accredited pedorthic facility, in Frederick, Md. as well as owner of New Balance- Frederick.