A lower extremity orthosis, configurable to be coupled to a person for gait assistance comprising: a thigh orthosis including left and right, interconnected thigh structures (303, 305) configured to be coupled to the person characterized in that the thigh orthosis further includes a single actuator configured to drive the left and right thigh structures (303, 305) equally and in opposite directions; wherein the lower extremity orthosis further comprises one or more of: a) a knee orthosis including a waist link configured to be coupled to the person, a thigh link, a shank link, configured to be coupled to the person, a knee joint and a torque generator, with said thigh link being rotatably connected both to said waist link at a hip joint and at the knee joint, said shank link being rotatably connected at the knee joint, and the torque generator being configured to exert torque about the knee joint to result in flexion or extension of a leg of a person wearing the lower extremity orthosis, with forces generated by the torque generator being reacted at said waist link and the shank link; b) a hip orthosis including a thigh link, a waist link, and another actuator, with said thigh link and said waist link being configured to be coupled to the person, said thigh link being rotatably connected to said waist link at a hip joint, and said actuator being positioned to provide a force on the thigh link during late stance and early swing; and c) an ankle orthosis including a shank structure configured to couple to a shank of the person and a foot structure configured to couple to a foot of the person, said shank structure and said foot structure being interconnected, whereby the ankle orthosis is configured to help prevent foot drop of the foot during a swing phase of a gait cycle. a thigh orthosis including left and right, interconnected thigh structures (303, 305) configured to be coupled to the person characterized in that the thigh orthosis further includes a single actuator configured to drive the left and right thigh structures (303, 305) equally and in opposite directions; wherein the lower extremity orthosis further comprises one or more of: a) a knee orthosis including a waist link configured to be coupled to the person, a thigh link, a shank link, configured to be coupled to the person, a knee joint and a torque generator, with said thigh link being rotatably connected both to said waist link at a hip joint and at the knee joint, said shank link being rotatably connected at the knee joint, and the torque generator being configured to exert torque about the knee joint to result in flexion or extension of a leg of a person wearing the lower extremity orthosis, with forces generated by the torque generator being reacted at said waist link and the shank link; b) a hip orthosis including a thigh link, a waist link, and another actuator, with said thigh link and said waist link being configured to be coupled to the person, said thigh link being rotatably connected to said waist link at a hip joint, and said actuator being positioned to provide a force on the thigh link during late stance and early swing; and c) an ankle orthosis including a shank structure configured to couple to a shank of the person and a foot structure configured to couple to a foot of the person, said shank structure and said foot structure being interconnected, whereby the ankle orthosis is configured to help prevent foot drop of the foot during a swing phase of a gait cycle. a) a knee orthosis including a waist link configured to be coupled to the person, a thigh link, a shank link, configured to be coupled to the person, a knee joint and a torque generator, with said thigh link being rotatably connected both to said waist link at a hip joint and at the knee joint, said shank link being rotatably connected at the knee joint, and the torque generator being configured to exert torque about the knee joint to result in flexion or extension of a leg of a person wearing the lower extremity orthosis, with forces generated by the torque generator being reacted at said waist link and the shank link; b) a hip orthosis including a thigh link, a waist link, and another actuator, with said thigh link and said waist link being configured to be coupled to the person, said thigh link being rotatably connected to said waist link at a hip joint, and said actuator being positioned to provide a force on the thigh link during late stance and early swing; and c) an ankle orthosis including a shank structure configured to couple to a shank of the person and a foot structure configured to couple to a foot of the person, said shank structure and said foot structure being interconnected, whereby the ankle orthosis is configured to help prevent foot drop of the foot during a swing phase of a gait cycle.