A stimulation device for activating at least one muscle involved in raising the foot while an individual is walking, comprising sensors which are to be placed on a lower limb of the individual, permitting calculation of a flexion angle of the knee； electrodes which are to be placed on the one or more muscles to be activated and able to electrically stimulate the one or more muscles, and a processing unit with computing means for calculating the value of the flexion angle of the knee on the basis of the measurement signals and for determining the oscillation phase in a walking cycle of the individual, and control means for the electrodes, the control means being designed to activate the electrodes only in the oscillation phase of a walking cycle of the individual, such that the electrodes generate an electrical stimulation with an intensity depending on the flexion angle of the knee, the intensity increasing as the flexion angle of the knee decreases, during the re-extension of the knee during the oscillation phase.
