The present invention relates to artificial limbs generally and to joints for the same. In particular, the present invention provides hydraulic functional units, generally classified as damping devices as connected between artificial limbs whereby enabling movement of artificial joints to closely correspond with natural human movement. In accordance with the invention, there is provided hydraulic damper control elements for prostheses which utilize a pressure differential due fluid flow as a direct control input for a at least one hydraulic valve. The valve can comprise a moveable element which abuts a mounted element which reduces the size of an aperture as the force increases. Further, a moveable body acts upon the valve enabling increase or decrease of flow of hydraulic fluid through the valve, whereby enabling an increase in gait by way of reduction of resistance to flow or reducing or stopping flow by way of a stumble recovery mechanism.