Spenco just been granted this patent: Contoured Support Insole Quote: A contoured insole especially advantageous for users with medium to high arches is disclosed. It comprises a generally foot-shaped base extending from a heel end to a toe end, which comprises a top surface and a bottom surface. The bottom surface of the base preferably further comprises two indentations formed integrally therein in a forefoot area and a heel area.

See more here:
Spenco patent for a contoured insole