Foot orthotics are widely used to manage a range of foot disorders from overpronation and collapsed arches to plantar fasciitis and other reasons for heel pain. The scientific evidence shows that they are generally very good at fixing many of the conditions as long as they are indicated for that condition, Foot orthoses generally get used to support the foot, when support of the foot may have absolutely nothing to do with the problem that the individual could have. This may lead to them being misused and mistakenly blamed for treatment failures. Another problem is that there are many different types of foot orthoses and also within every type of foot orthotic, there is an nearly unlimited variance in the design features that could be incorporated into them. If even one of those design features isn't good for the person, then the likelihood of that foot orthotic doing any good is potentially reduced.
This is why the choice of the various designs is actually dependant on the experience and expertise of the medical professional. The podiatrist will decide on the design features required for the individual and if the device needs to be customized for the person or if a mass produced less costly foot orthotic can be used. In relation to custom made orthotics, the medical professional needs to take a plaster cast or optical scan of the foot held in specific positions for the foot orthotic to be made on. When it comes to the design of the device different elements are taken into account. For example, if the patient has posterior tibial tendon dysfunction, then something like a MOSI type foot orthotic is necessary. The MOSI has special modifications to handle the range of issues that occur in that disorder. When the concern is related to a lack of impact absorption, then the orthotic should be designed to support that. The range of choices is endless and depends upon the condition present and the wishes of the treating clinician.