Gait is a high-level locomotion pattern peculiar to humans. Human gait is controlled either voluntarily or automatically, the latter with very little attention to the task. In fact, both are probably involved continually to a varying degree in daily locomotion. The central control mechanisms of human gait remain unclear. It is generally believed that, while certain subcortical structures, such as the pedunculopontine nuclei and the basal ganglia, play important roles in automatic walking, the cerebral cortex also becomes involved due to changes in the level of effort and attention demands. Is freezing of gait (FOG) in Parkinson's disease (PD) affected by the level of automatic or voluntary control? Another factor may be a crucial key in determining the underlying pathological mechanisms of FOG in PD. Clarifying the degree to which the central nervous system's control of gait is involved in FOG in Parkinson's disease may reveal its underlying mechanism.