I had a ProLab client call me stating that she wanted to make a soft orthotic for a patient who had a significant pes planus foot type and was suffering from plantar fasciitis. She wanted to make a soft device because she said the patient had “hard orthotics” in the past and did not tolerate them.
The first thing that we need to think about when deciding on an orthotic prescription is to determine the goal of therapy. Since this patient’s primary complaint is arch pain due to plantar fasciitis, our goal with the orthotic device should be to reduce tension on the plantar fascia. To accomplish this we need a device that is going to decrease arch collapse in order to decrease lengthening of the arch and increased tension on the plantar fascia. In general such an orthosis should conform very close to the arch of the foot and incorporate valgus forefoot correction.
Given that this patient also had pes planus, they are much more likely to feel the medial edge of the orthosis, and perceive the orthosis as too hard if the device was not made with a medial flange. The medial flange will increase the width of the orthotic in the mid arch, spreading the force over a larger surface area and preventing the patient from coming down on the medial edge of the orthosis.
In most cases, it is not the specific material or the rigidity of the material that causes the patient to think that the orthosis feels too hard but rather the fact that the medial edge of the orthosis is irritating the plantar foot of that the force is not spread over a large enough surface area leading to more localized pressure.
I advised our client that she would likely find that the softer orthosis will deform so much under the foot that it is not very likely to effectively reduce tension on the plantar fascia and her chances of achieving optimum clinical outcomes are much reduced. Rather, we recommend a more rigid orthosis with the medial flange and a deep heel cup, so that we not only reduce tension on the plantar fascia effectively but also make a device that the patient will find comfortable.
ProLab takes a scientific approach with our orthoses by integrating evidence-based medicine into orthotic therapy. Our team of Medical Consultants regularly evaluates the medical literature pertaining to orthotic therapy and biomechanics. ProLab clients are encouraged to contact a Medical Consultant whenever they have questions about an orthotic prescription.
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