A gait disorder support apparatus and gait disorder support method capable of detecting an onset sign of a gait disorder associated with motor symptoms in advance and performing motion assist are proposed. The onset sign of the gait disorder associated with the motor symptoms of a wearer is detected based on the correlation between a gait cycle and a reduction ratio of the gait cycle as compared to immediately preceding gait； and when the onset sign of the gait disorder is detected, a drive unit is controlled so that the drive unit applies assist power to a knee joint of the wearer； and on the other hand, when the onset sign of the gait disorder is not detected, the drive unit is controlled so that driving torque by the drive unit does not hinder the wearer's gait motion.
