Fig. 9

Average sagittal-plane leg trajectories and trainer forces for six patients who have survived strokes (P1–P6) across six practice days. For each patient, the black trajectories on the left show the average non-assisted leg trajectory during the initial trial of each practice day. The red trajectories in the right column show the average leg trajectory for the last trial of each day, in which the patient received assistance from a trainer using the telerobotic system. The red arrows show the average commanded trainer forces (\({\varvec{F}}_{{\varvec{T}}}\)) applied from heel-off to heel-strike. Trainer force transmission was software limited to be in the anterior and vertical directions, except P3 on Day 4, who received resistive forces