Critical light reflection at a plastic/glass interface and its application to foot pressure measurements

The necessary properties of plastic materials for use in a method of foot pressure distribution measurements have been assessed, and the mechanisms in operation at an illuminated plastic to glass interface underload have been investigated. A hypothesis is given of the physical principles upon which the operation of this technique is based and it is shown that a calibrated analysis of both the static and dynamic distribution of pressure under the foot is possible by this technique.