The primary objective of this project is to assess and compare the effects of robotic-assisted versus manually-assisted locomotor training using the body-weight support (BWS) on sub-tasks of walking. Specifically, we believe that at least four sub-tasks of walking are differentially affected by the robotic-assisted training when compared to manually-assisted training (propulsion, transition from stance to step, stepping, and equilibrium). The investigators hypothesize that robotic-assisted training will have a greater effect on improving propulsion, transition and equilibrium. The effect of these two modalities on adaptability, a fifth sub-task of walking, is unclear; therefore, a development component of the pilot project will involve establishing a quantitative measure of adaptability and assessing differential effects of training. Participants will be randomized to one of two training groups: robotic-assisted or manually-assisted, and evaluated for performance on sub-tasks of walking.