Pelvic motions are of great importance while walking, and have thus to be taken into account when developing and controlling rehabilitation devices. This paper will first introduce a new reeducation devices for paraplegic people: the WalkTrainer. This device is composed of a leg and pelvic orthosis, an active bodyweight support and closed loop muscle stimulation. Second, the six degrees of freedom (DOF) of the pelvis will be measured by using the WalkTrainer on a population of twenty healthy subjects. Each DOF was successfully measured and can be analyzed as a function of time or gait cycle. Third several models that predict the pelvic motion amplitude as a function of various parameters (speed, size, …) will be proposed and analyzed. Fourth, pelvic trajectories will be programmed on the WalkTrainer and applied on healthy subjects by the mean of the pelvic orthosis. In that phase one of the previously proposed models will be implemented. A force reduction of 20% is measured on the pelvic orthosis when the pelvic motion amplitude prediction model is used.