Energy storing foot prosthesis with improved plantar flexion

#1. Field of the Invention

#This invention relates to foot prostheses in general, and specifically to a prosthetic foot characterized by a unitary foot and heel construction, and an auxiliary ankle construction which permits the flexibility of the prosthesis to be selectively determined and easily changed.

#2. Background of the Invention

#Having thus summarized the general nature of the invention and its essential features and advantages, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which:

#FIG. 1 is a side elevation view of one preferred embodiment of a prosthetic foot;

#FIG. 2 is a side elevation view of an alternative embodiment of a prosthetic foot;

#Referring to the drawings, and particularly to FIG. 1, I show one preferred embodiment of a foot prosthesis 10 constructed in accordance with the teachings of the invention. The foot 10 generally includes a forefoot member 80, a sole member 50, and an auxiliary support member 86 operatively and demountably attached to each other at the arch section 44. Attachment is preferably accomplished using suitable nut and bolt combinations 104 associated with a load-transmitting metallic plate 106. The auxiliary member is preferably attached to the forefoot member such that the auxiliary member may add to the stiffness of the ankle portion of the forefoot member. If desired, a retaining band 70 may be provided at the ankle section 42. A compressible member 116 may be provided between the auxiliary member, and the forefoot member. Function blocks 118, 120, 121, and 119 (FIG. 2) may also be provided in order to vary the length of the effective lever arms of the various members. If indicated, the forefoot and sole portions can be permanently secured to each other, as by epoxy adhesive, a polyurethane resilient layer, or the like.

#The forefoot member 80 preferably includes a substantially rigid upper attachment section 40, a forward and downward curving ankle section 42, an arch section, 44, and a distal toe section 46. The sections 40, 42, 44, and 46 are preferably formed integrally with one another and simultaneously by the incorporation of a plurality of laminae embedded in a hardened, flexible polymer.

#In the particular embodiment shown, the sole member 50 includes an attachment section 58 and a heel section 54 extending substantially rearward from said attachment section 58. The sections 58 and 54 are preferably formed integrally with one another and simultaneously by the incorporation of a plurality of laminae embedded in a hardened, flexible polymer as described herein.