A combined active and passive leg prosthesis system is disclosed, and a method of performing a gait cycle by a leg prosthesis system is disclosed, for replacing a missing lower extremity of an individual to perform a gait cycle by the leg prosthesis system and/or the method. In at least one embodiment, the leg prosthesis system includes at least one movable joint, and a disconnectable active drive unit to drive the movable joint and a passive brake unit to brake the movable joint when the drive unit is disconnected.
