Model & Instrument Development Corporation

Seattle Orthopedic Group, Inc.

Donald L Poggi

Stewart L Atkinson

Ernest M Burgess

David E Moeller

Drew A Hittenberger

An inventive prosthetic ankle for use between a pylon and a prosthetic foot to support a person's weight on the ground comprises an integrally formed, generally C-shaped carbon-fiber composite flexure member having upper, lower and curved legs. The upper leg is connected to a lower end of the pylon, and the lower leg is connected to an upper surface of the prosthetic foot. The curved leg interconnects the upper and lower legs, with the curved leg extending from a forward edge of the upper leg to a forward edge of the lower leg in a rearwardly-facing arc about a medial/lateral axis positioned forward of the pylon. The curved leg is dog-boned to facilitate canting of the pylon with respect to the prosthetic foot in the medial/lateral plane. Also, the curved leg is resilient to resiliently bias the upper and lower legs apart from one another so the legs are positioned in a spaced-apart relationship with respect to one another when the person's weight is off the prosthetic ankle. The resilient biasing also allows the upper and lower legs to pivot toward one another about the medial/lateral axis when the person's weight is on the prosthetic ankle at heel strike. As a result, the prosthetic foot falls flat on the ground soon after heel strike. A limit strap coupled between the upper and lower legs limits rotation of the upper and lower legs away from each other about the medial/lateral axis so the flexure characteristics experienced by an amputee during step-off are substantially determined by the flexure characteristics of the toe portion of the prosthetic foot.

Prosthetic ankle and walking system

In a prosthetic foot constructed to store strain energy as the foot reacts to the load of the amputee's body during walking, running, jumping, etc., and then to release the stored energy to create foot lift and thrust which complements the user's natural stride, a monolithic cantilever beam made of a hardened polymer is provided as the keel of the foot with an ankle attachment fitting for connection to a standard upper prosthesis. A flexible foamed polymer is molded about the keel, in the shape of a natural foot, to transfer horizontal loads to the keel and to serve as a cosmetic cover.

Growing community of inventors

Bainbridge Island, WA, United States of America

Donald L Poggi