A battery-powered electromechanical device which is a component of an external lower limb prosthesis designed to functionally replace, in part or total, an absent knee, wherein the principle of operation for motion control is based on hydraulic, pneumatic, or magnetorheological actuation regulated by a motion-feedback mechanism using electronic sensors and software. It is intended to respond to changes in motion in real-time by continuously sensing knee flexion speed and temperature and instantly adjusting motion resistance within a single step. Known as a microprocessor-controlled knee (MPK), it may have various designs and functional features for support during a variety of activities.