A method for applying a gravity compensation control torque to a human joint in order to reduce a load on muscles via a control algorithm, comprising the steps of: determining that it is feasible to apply the gravity compensation control torque responsive to an absolute value of a relative angular velocity between a first and a second segment of a first joint being substantially zero; determining that it is feasible to apply the gravity compensation control torque responsive to the absolute value of said relative angular velocity between said first and second segments of said first joint being not substantially zero, and further responsive to: determining a mechanical energy feasibility value of said gravity compensation control torque, wherein said mechanical energy feasibility value represents a relationship between a value of an assisted muscle torque and a value of an unassisted muscle torque; determining a metabolic energy feasibility value of said gravity compensation control torque, wherein said metabolic energy feasibility value represents a relationship between a value of a metabolic cost of assisted control and a value of a metabolic cost of unassisted control; and determining that it is feasible to apply the gravity compensation control torque based both said mechanical energy feasibility value being responsive to a magnitude of said assisted muscle torques not exceeding a magnitude of said unassisted muscle torque, and said metabolic energy feasibility value being responsive to metabolic cost of said assisted joint motion not exceeding metabolic cost of said unassisted joint motion; and responsive to determining that it is feasible to apply the gravity compensation control torque, applying the gravity compensation control torque to the human joint. determining that it is feasible to apply the gravity compensation control torque responsive to an absolute value of a relative angular velocity between a first and a second segment of a first joint being substantially zero; determining that it is feasible to apply the gravity compensation control torque responsive to the absolute value of said relative angular velocity between said first and second segments of said first joint being not substantially zero, and further responsive to: determining a mechanical energy feasibility value of said gravity compensation control torque, wherein said mechanical energy feasibility value represents a relationship between a value of an assisted muscle torque and a value of an unassisted muscle torque; determining a metabolic energy feasibility value of said gravity compensation control torque, wherein said metabolic energy feasibility value represents a relationship between a value of a metabolic cost of assisted control and a value of a metabolic cost of unassisted control; and determining that it is feasible to apply the gravity compensation control torque based both said mechanical energy feasibility value being responsive to a magnitude of said assisted muscle torques not exceeding a magnitude of said unassisted muscle torque, and said metabolic energy feasibility value being responsive to metabolic cost of said assisted joint motion not exceeding metabolic cost of said unassisted joint motion; and responsive to determining that it is feasible to apply the gravity compensation control torque, applying the gravity compensation control torque to the human joint. determining a mechanical energy feasibility value of said gravity compensation control torque, wherein said mechanical energy feasibility value represents a relationship between a value of an assisted muscle torque and a value of an unassisted muscle torque; determining a metabolic energy feasibility value of said gravity compensation control torque, wherein said metabolic energy feasibility value represents a relationship between a value of a metabolic cost of assisted control and a value of a metabolic cost of unassisted control; and determining that it is feasible to apply the gravity compensation control torque based both said mechanical energy feasibility value being responsive to a magnitude of said assisted muscle torques not exceeding a magnitude of said unassisted muscle torque, and said metabolic energy feasibility value being responsive to metabolic cost of said assisted joint motion not exceeding metabolic cost of said unassisted joint motion; and