An apparatus for harvesting energy from motion of a human or animal body segment and providing the energy to an electrical load is disclosed. The apparatus comprises a generator operatively coupled to the body segment such that particular movement of the body segment causes the generator to output a generator current and to oppose the particular movement of the body segment with a generator torque. An electrical load is coupled to receive the generator current. A control system is operatively connected between the generator and the electrical load and is configured to control the generator torque during the particular movement of the body segment. Corresponding methods are also disclosed.