stimulation of muscle deprived of nervous control with a view of providing muscular contraction and producing a functionally useful moment". Offner's patent described a system used to treat foot drop. The first commercially available FES devices treated foot drop by stimulating the peroneal nerve during gait. In this case, a switch, located in the heel end of a user's shoe, would activate a stimulator worn by the user. Common applications Spinal cord injury Injuries to the spinal cord interfere with electrical signals between the brain and the muscles, resulting in paralysis below the level of injury. Restoration of limb function as well as regulation of organ function are the main application of FES, although FES is also used for treatment of pain, pressure, sore prevention, etc. Some examples of FES applications involve the use of neuroprostheses that allow the people with paraplegia to walk, stand, restore hand grasp function in people with quadriplegia, or restore bowel and bladder function. High intensity FES of the quadriceps muscles allows patients with complete lower motor neuron lesion to increase their muscle mass, muscle fiber diameter, improve ultrastructural organization of contractile material, increase of force output during electrical stimulation and perform FES assisted stand-up exercises. Walking in spinal cord injury 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. Kralj's approach was extended by Graupe et al. into a digital FES system that employs the power of digital signal processing to result in the Parastep FES system, based on US Patents 5,014,705 (1991), 5,016,636 (1991), 5,070,873 (1991), 5,081,989 (1992), 5,092,329 (1992) and related foreign patents. The Parastep system became the first FES system for standing and walking to receive the US FDA approval (FDA, PMA P900038, 1994) and become