You will be asked to participate in 1-16 testing sessions at UNC-Chapel Hill. You will need to wear comfortable shoes that can be laced up for the testing session. You will start by filling out a questionnaire about your overall behavior, mood, and memory (participants with stroke). We will then do some brief tests of your movements and coordination and have you walk across a 16-foot mat that records your walking speed. The investigators will next attach small, reflective balls to your pelvis, thighs, calves, and shoes. These small balls act as a way to capture walking data while you are in the lab. Finally, we will place sensors on your muscles to measure their activity. You will be asked to walk at a comfortable speed on the treadmill for five minutes to practice, and 20 minutes to collect data on different walking conditions. We will show you a graph on a TV that is mounted in front of the treadmill. The graph will show you how far you are stepping through with the limb wearing an exo. We will ask you to reach certain targets on the graph. If completing the additional training (participants with stroke), we will do the same type of testing on flat ground over sensors that are mounted in the floor. You will be asked to make several passes over this specific part of the ground before the initial training, after the initial training, and then once again after three months of the training.