Abstract: A knee mechanism for a lower limb prosthesis which maintains knee stability over an initial range of flexion and includes an upper member for connection to or forming part of the thigh component of a prosthesis, a lower member for connection to or forming part of the shin component of a prosthesis, and a slider and a crank connecting the upper member to the lower member. The locus of the instantaneous center of rotation of the mechanism is a curve which commences above the knee and posterior to the load line and which, over an initial range of flexion of the mechanism, moves continuously downwards and to the posterior, the curve being convex towards the posterior. The lower member, the slider and the crank preferably constitute a slider crank mechanism with the crank pivotally connected to the upper and lower members and the slider pivotally connected to the lower member and slidably connected to the upper member.

Abstract: An adapter assembly which is particularly advantageous in allowing for adjusting and positioning of prosthetic devices which are attached to a stump or stump socket. The adapter is particularly advantageous for orienting and positioning of a Symes prosthesis, due to the small space requirements. In accordance with a preferred embodiment, an interface member is attached to a stump socket, with a nut movably disposed inside of a cavity of the interface member. The nut includes an aperture extending therethrough, and receives a hollow laminating bolt which clamps the prosthesis and adapter assembly in place to allow the user to test the prosthesis. If adjustments are needed, the hollow bolt can be loosened, and adjustments performed via the movably disposed nut. Once a desired position is achieved, a resin is injected through the laminating bolt and into the cavity of the interface. After the resin has hardened or cured, the hollow laminating bolt is replaced with a solid bolt.