A colleague recently called about a patient who felt his orthotic device was too hard. He wanted to know if he could possibly make a softer orthotic for this patient, who weighs 310 pounds.
Or course, obese patients put significant pressure onto their feet. When they wear an orthosis, there is significant force between the orthosis and the foot, much more so than what would occur with a patient of average weight. This means that these patients have more potential to feel the arch of the orthosis as too high or too hard.
Unfortunately, if you make a softer orthosis for such a patient, the device is likely to collapse under the foot very quickly and not provide adequate support to relieve the patient’s symptoms.
A better idea is simply to make a wider orthosis. A wider orthosis will spread force across a larger surface area so the patient is much less likely to feel the device is too hard or too high.
For obese patients, I recommend using at least a wide orthosis and, in many cases, a medial flange. A wide device will extend to the medial aspect of the foot and a medial flange will wrap around the medial arch. Both of these will help redistribute force better than a standard width orthosis and are almost always more comfortable for these patients.
Also, these wider devices allow you to use a more rigid orthosis that is likely to provide the patient adequate support.
Editor's note: This blog was originally published at http://www.prolaborthotics.com/Blog/tabid/90/EntryID/503/Default.aspx  and has been adapted with permission from Lawrence Huppin, DPM, and ProLab Orthotics. For more information, visit www.prolaborthotics.com  .