Action observation and motor imagery have no effect on balance and freezing of gait in Parkinson’s disease: a randomized controlled trial

BACKGROUND: Combining action observation (AO) and motor imagery (MI) training may induce greater brain activity in areas usually involved in Parkinson’s disease (PD) and lead to greater behavioral and neurophysiological effects than when used separately. AIM: To determine the effects of combining AO, MI, and gait training on balance and freezing of gait in individuals with PD. DESIGN: This is a single-blinded, randomized controlled clinical trial. SETTING: Laboratory of Intervention and Analysis of Movement (LIAM) from the Department of Physical Therapy of a Brazilian University. POPULATION: Study sample consisted of individuals diagnosed with idiopathic PD by a neurologist specialized in movement disorders. METHODS: 39 individuals with PD were divided into experimental (EG=21) and control groups (CG=18). EG performed 12 sessions of AO, MI, and gait training, whereas CG watched PD-related educational videos and performed 12 sessions of gait training. Balance (measured using the Mini Balance Evaluation Systems Test [MiniBESTest]) and freezing of gait (measured using the Freezing of Gait Questionnaire) were reassessed one day after the end of the intervention. RESULTS: We did not observe significant intra- and intergroup differences in freezing of gait. For the EG, we observed a significant intragroup difference in the total score of MiniBESTest (F=5.2; P=0.02), and sensory orientation (F=4.5; P=0.04) and dynamic gait (F=3.6; P=0.03) domains. MiniBESTest domains were not different between groups. CONCLUSIONS: Combining AO, MI, and gait training was not more effective than isolated gait training for balance and freezing of gait in individuals with PD. CLINICAL REHABILITATION IMPACT: MI training can moderate AO effects and enhance motor learning when both therapies are combined. Therefore, this approach may still have the potential to be included in the treatment of PD. New studies should investigate whether the factors that influence these results are related to the protocol’s sensitivity in changing the evaluated parameters or to the time and intensity of AO and MI training.