Patent ID: 6086616
Filing Date: 2000-07-11
Classification: A61F,F16F

Abstract:
A prosthetic leg with a knee joint, comprising an upper thigh member to which a load of a wearer is incurred through the thigh, a lower thigh member connected to said upper thigh member at the knee portion, and a knee joint including at least two front and rear links, one being located forwardly of the knee and the other being located backwardly of the knee, said two links together with said upper thigh member and said lower thigh member constituting a constrained chain, said upper thigh member and said lower thigh member being bendably connected together through said knee joint, wherein an extension auxiliary mechanism having a spring is disposed between said front link and said rear link, said extension auxiliary mechanism generates an extension torque determined by a product of a force caused by biasing of said spring and a distance from a line of action of said force to the center of rotation of said rear link, and said distance becomes approximately zero when a bending angle of the knee exceeds a predetermined angle.