Patent ID: 7572299

Claim:
A prosthetic foot device configured to provide a variable resistance in response to a load factor, the device comprising: a) first and second foot members, at least one of the foot members having an attachment end configured to be coupled to an amputee, and an opposite end, the first foot member including: an upper forefoot member having an attachment section configured to be coupled to a socket, and extending downwardly therefrom; and a lower heel member having a heel section disposed at a natural location of a heel of a user, and an attachment section attached to the upper forefoot member; and the second foot member including a forefoot reinforcement member, disposed above the upper forefoot member; b) at least one of the first and second foot members being a resilient member capable of storing energy during deflection; c) a chamber, associated with one of the first and second foot members; d) a piston, associated with another of the first and second foot members and movable in the chamber, the piston and chamber defining a volume that changes in response to the load factor; e) at least one of the piston and the chamber being located closer to the opposite end of the at least one of the foot members than to the attachment end; f) at least one aperture, formed through the piston and in communication with the chamber; g) a variable viscosity fluid, disposed in the chamber and displaceable through the at least one aperture in the piston in response to the load factor; and h) the variable viscosity fluid having a viscosity that is variable corresponding to the load factor to vary an ability of the variable viscosity fluid to flow through the at least one aperture.