Abstract: As with orthotics that are all custom devices molded through a proprietary foam and plaster method and are designed to fit the plantar surface of the foot with full contact, it is necessary to provide a method of applying pressure to the orthotic in a manner that mimics the manner in which a foot applies pressure to it. This is done by applying pressure to a loose fitting diaphragm that is contained within a rigid frame so as to limit expansion of the diaphragm past the boundaries of the device. Further the device contains the diaphragm in such a manner that the diaphragm; 1) Exerts minimal force on the orthotic so as not to bias the deflection of the orthotic by the mechanical pressure of the diaphragm. 2) Uses minimal force to expand the diaphragm so as not to bias the pressure reading indicating how much force is being applied to the orthotic. 3) Closes in such a manner that pushes and holds the orthotic device up against the measuring rod, front window and bottom reference baseplate.