The shapes of right
and left feet were shown alternatively on the screen. When the patient’s stride fell within the set standard deviation (SD), the footfalls were synchronized with the target shapes and ‘‘well done’’ appeared on the screen. When the stride fell outside the SD, the footfalls and target shapes were out of synchronization and the patient was informed, on the screen, of which footfall was outside of the SD and prompted to take a longer or shorter step with the respective foot. The auditory cue consisted of musical beats synchronized with the visual cues with a frequency of 0.5 c/s.