Robotic assistive devices have been developed and are now being introduced in clinical environments. Such robots can advantageously provide long raining, with quantifiable mobilization (force and position). But in the event of a complete lesion the patient’s muscles remain completely passive. To overcome that issue electrical muscle stimulation can be employed. The complex nature of the muscles associated to the dynamics of walking, require subtle stimulation schemes which rely on position and force information provided by the robot. The combination of muscle stimulation (preferably in a closed loop manner to avoid rapid exhaustion and guarantee better control) and robotic mobilization optimizes the afferent feedback provided to the subject and allows an effective muscle training. The WalkTrainer that is one of these reeducation devices, will be extensively presented in this chapter.