The relationship between motor planning and freezing of gait in Parkinson's disease.

Objective: To examine how a cued change in motor plan influences Parkinson's disease (PD) patients with freezing of gait (FOG) (PD FOG; n=10), compared with those without FOG (PD non-FOG; n=10) and healthy controls (n=10).

Methods: Participants walked through a doorway in three experimental conditions: no cue; cue before gait initiation; and cue after gait initiation. The light cue was presented at the end of the pathway and signified that individuals must walk to the cue, turn around and return to starting position.