Changes in plantar surface shape induced by corrective forefoot eversion.

Abstract

An investigation is presented of the change in shape of the plantar surface of the foot when the forefoot is everted (prohated) from its natural unloaded orientation into a corrected position frequently used during shoe insert fabrication. Both free and corrected casts were made of 13 asymptomatic feet using established casting techniques. Digital scans capture each plantar surface shape into a computer where an analysis of the transverse slope of the plane is made at various longitudinal locations between midheel and metatarsal head regions. The profile of the slopes show results which are consistent with pronation about the midtarsal joint. These results may be useful as a first stage in establishing the appropriate shape corrections to be used in a computer-aided design system for shoe insert design.