Experimental protocol
Data collection took place in the virtual reality lab in the Biomechanics Research building at the University of Nebraska. We allocated participants evenly into three parallel groups with five participants each: Exosuit-only (Exo-only), Split-belt only (Sb-only), and Simultaneous (Exo-Sb). All participants in each group walked on an instrumented Split-belt Treadmill (Bertec®, Columbus, Ohio) that sampled kinetic data at 1000 Hz. Each group completed a 3-minute baseline walking trial with the belts tied at 1.0 msWe measured kinematics at 100 Hz using a calibrated 16-camera motion capture system (Vicon Motion Systems, Ltd, Oxford, United Kingdom). Participants wore a close-fitting singlet and their preferred walking shoes throughout the entirety of the collection. We placed a marker set consisting of 33 retro-reflective markers (12.7 mm) on bony landmarks bilaterally on the feet (head of 1st and 5th metatarsal, base of the 2nd phalange, calcaneus, heel), shank (medial and lateral malleoli, tibial tuberosity, lateral shank), knee (medial and lateral epicondyles of the femur), thigh (lateral thigh, greater trochanter, ventral-distal thigh), and pelvis (anterior superior iliac spine, posterior superior iliac spine, sacrum) to track lower extremity kinematics following a modified Helen-Hayes marker set. We put the retro-reflective markers directly on the skin, on the surface of the singlet, or on top of the shoes over the foot landmarks. Participants wore a safety harness attached to a ceiling mount throughout all collection trials. The harness did not support body weight.
Protocol Set-up. Times, belt speeds, and trials for each experimental group. The time periods, Baseline (blue), Adaptation (red), and Post-adaptation (purple), are represented by the outlines. Numbers at the top represent the minutes spent in each section. D stands for dominant and ND stands for non-dominant. The color filling represents the individual belt velocities of the split-belt treadmill. Grey represents the standard velocity at 1.0 ms