Fore-aft resistance applied at the center of mass using a novel robotic interface proportionately increases propulsive force generation in healthy nonimpaired individuals walking at a constant speed.

Only 17 healthy, nonimpaired adults were tested, so the results do not show what would happen in patients with gait impairment. Walking was tested at one target speed, 1.0 m/s ± 0.2 m/s, so it does not tell us how people would respond at other speeds. There was no true 0 percent resistance condition, so the smallest added load cannot be compared with unresisted walking. The robotic interface held the pelvis and may have reduced braking forces, so the observed strategy could be partly device-related. No EMG was measured, so the study shows mechanical output but not which muscles drove it. Visual feedback was needed to keep speed constant and may have affected propulsion.

Do not conclude that fore-aft resistance improves rehabilitation or that the hip strategy shown here will transfer to patients. The study tested only healthy nonimpaired adults in a robotic interface at one speed, and the authors describe patient use as future work.