Abstract: A robotic knee for mounting on an upper leg stump of an allows movement from a standing position to a normal walking position and then to a kneeling position and return to a standing position. A mounting plate receives the upper leg stump of an amputee. The knee includes a housing having a drive motor which can be rotated in one direction to bend the knee and then reversed to straighten the knee. The drive motor turns a worm gear which engages a main drive gear. A pair of extension pulleys is mounted on a main drive gear shaft attached to the main drive gear. A pair of extension cables is attached at a first end to the extension pulleys and wrapped thereon. A second end of the extension cables is attached to a front portion of a mounting plate. A pair of flexion pulleys is also attached to the main drive gear. A pair of flexion cables is attached at a first end to the flexion pulleys and wrapped thereon. A second end of the flexion cables is attached to a rear portion of the mounting plate.