Selective and gradual foot-clearance support in the healthy control subjects and stroke survivors. A: Mean normalized gait parameters for the trials in which the healthy subjects walked with the compliant (HC) and stiff (HS) step-height VMC. The mean parameters are calculated during the last 10 steps of the last exposure block. C: Mean relative contribution of the different gait phases to the cycle time for both tested conditions. As a reference, also the relative gait phases during walking in the zero impedance mode (HZ) are shown. B: Mean normalized gait parameters for the trials in which stroke survivors walked with the compliant (PCV) and stiff (PSV) step-height VMC, in combination the visual feedback. Mean parameters are calculated during the five steps of the longest exposure block. D: Mean relative gait phases for both tested conditions. The error bars indicate the standard error of the mean. *p < 0.05. ++ indicates a significant difference between the compliant and stiff VMC.