An artificial substitute for a transfemoral (above-the-knee) and/or knee disarticulation amputation designed as a component of an external lower-limb prosthesis to restore some of the appearance and/or function of the normal anatomy. It typically consists of metal and plastic and is constructed as a multiple-axis joint rotation, mechanical hinge that incorporates friction adjustment and a simple swing control that permits variable walking speed. A common design, known as a ?fourbar? knee, is very stable during early stance phase (beginning of a step), reduces the leg?s length when beginning a step lowering the risk of stumbling, and bends in the swing phase or when the user sits down.