Abstract: An improved prosthetic foot comprising an energy storage keel and a modified ball and socket ankle joint. The foot and ankle are casted as a single unit, from a urethane copolymer. The movement of the ankle joint is controlled by the use of elastic inserts. These inserts are of various durometers and are interchangeable. Modifying the gait characteristics of this invention can be easily accomplished by simply removing and replacing the elastic inserts. These inserts can be installed without any tools or disassembly of the ankle joint. The attachment to a prosthetic limb is accomplished through the use of an attachment bolt; this bolt also serves as a strengthening and stiffening element for the ankle joint. The energy storage keel of this present invention is comprised of a forefoot having an arch and a resilient toe, which absorbs loads as the user walks and returns the absorbed energy consistent with an energy storage and return foot.