Performance obtained during the BF phase in the first and last day of treatment. Results obtained by the three patients in the first (upper panels) and last (lower panels) day of treatment during the BF phase. Each asterisk and circle indicate the mean value, among 10 consecutive revolutions, of the work produced by the paretic and healthy leg, respectively. The black line shows the target value and the surrounding yellow area represents the tolerance band. In all panels, double vertical axes are used to indicate the absolute work value and the minimum and maximum target values in percentage of WPLmax.