A wearable orthosis that can apply controlled, dissipative loads to the lower limbs is described. Through computer control of the dissipative loads, the device is capable of regulating limb trajectories and of emulating dissipative mechanical environments. The orthosis covers the left and right hip and knee joints allowing hip flexion-extension and abduction-adduction, and knee flexion-extension motions. The hip and knee flexion-extension joints are coupled to magnetic particle brakes which can apply resistive torques. Torque and position sensors measure joint properties and the system is under computer control. The orthosis was designed for applications of restoring gait to individuals with paraplegia due to spinal cord injury by electrical stimulation of muscles, but can also be used in teleoperator and virtual environment systems.