Seeing another person doing a movement can activate the brain to initiate movement: the mirror system is a neurological process which involves the preparation our brain makes to take an action. By seeing another person doing a movement our brains prepare to take this action ourselves.

Dynamic movement cues obtained from observing and imitating actions may be more effective than other forms of cueing, and recent studies have indicated some benefits of imitation practice within rehabilitation programmes for stroke and Parkinson’s

http://beamlab.lab.ls.manchester.ac.uk/research/parkinsonsdisease/ (2017) [20/05/2017]