kralj and his colleagues described a technique for paraplegic gait using surface stimulation, which remains the most popular method in use today. electrodes are placed over the quadriceps muscles and peroneal nerves bilaterally. the user controls the neuroprosthesis with two pushbuttons attached to the left and right handles of a walking frame, or on canes or crutches. when the neuroprosthesis is turned on, both quadriceps muscles are stimulated to provide a standing posture. electrodes are placed over the quadriceps muscles and peroneal nerves bilaterally. the user controls the neuroprosthesis with two pushbuttons attached to the left and right handles of a walking frame, or on canes or crutches. when the neuroprosthesis is turned on, both quadriceps muscles are stimulated to provide a standing posture.