Action observation improves freezing of gait in patients with Parkinson's disease

Freezing of gait (FOG) is a disabling impairment for people with Parkinson's disease (PD) and may not respond to medications. The effectiveness of physical therapy for FOG is debatable. Action observation strategies to overcome FOG may enhance physical training.

To assess whether action observation, combined with practicing the observed actions, may reduce FOG episodes.

Twenty patients with PD entered a single-blind trial and were randomly assigned to the experimental (Action) or control (Landscape) groups. Those in the Action group watched video clips showing specific movements and strategies to circumvent FOG episodes, whereas those in the Landscape group watched video clips of static pictures showing different landscapes. All patients underwent identical physical therapy training, 3 sessions a week for 4 weeks.

The FOG Questionnaire score and the number of FOG episodes were significantly reduced in both groups after the training period. At follow-up examination (4 weeks after the end of the intervention), a significant reduction in the number of FOG episodes was observed only in the Action group. Motor performance (walking and balance) and quality-of-life assessments were significantly improved in both groups at the end of training and at follow-up.

Our results suggest that action observation has a positive additional effect on recovery of walking ability in PD patients with FOG. Further studies on the combination of observation and imitation to supplement a physical training program may result in an innovative rehabilitative approach for FOG.