Artificial knee joint with a push rod biased to rotate a prosthetic lower leg rapidly to align with a residual thigh

An artificial knee joint for connecting a residual thigh of a prosthetic wearer to a prosthetic lower leg, said knee joint comprising:

• a joint seat including a joint body and a rotatable member that is adapted to be connected fixedly to the thigh and that has a pivot end connected pivotally to said joint body, and a free end;
• a hollow support frame having an upper end and a lower end that is adapted to be connected fixedly to the lower leg;
• a connecting unit for connecting said upper end of said support frame rotatably to said joint body so as to permit rotation of the lower leg relative to the thigh;
• a hydraulic device disposed within said support frame and having a piston rod that is disposed movably in said support frame and that is connected to said joint body;
• a push rod disposed movably within said joint body and movable between an extended position, where an upper end of said push rod projects from said joint body and where said free end of said rotatable member is spaced apart from said joint body to align the lower leg with the thigh, and a retracted position, where said upper end of said push rod is retracted into said joint body and where said free end of said rotatable member abuts against said joint body;
• and
• a biasing member for biasing said push rod to said extended position so that said free end of said rotatable member turns away from said joint body, thereby facilitating movement of the lower leg to a full extension position, where the lower leg is aligned with the thigh.