The effectiveness of action observation and motor imagery in freezing of gait, speed, physical function and balance in Parkinson's disease: a systematic review and meta-analysis.

Background: Parkinson's Disease (PD) is a neurodegenerative disease that produces balance and gait disorders. Action observation (AO) and motor imagery (MI) therapies appear to facilitate motor planning influencing balance and gait relearning.

Objective: To investigate the effectiveness of AO and MI in isolation or combined (AO-MI), compared to sham interventions for the improvement of freezing of gait (FOG), speed, physical function and balance among individuals with PD.

Methods: PubMed, Web of science, PEDro, Scopus and Cochrane Library were searched from inception to January 2024. Studies included were randomized controlled trials (RCTs). The study quality and risk of bias were assessed with PEDro scale and the Cochrane tool, respectively. The certainty of evidence was evaluated with GRADEpro GDT.

Results: Eight RCTs were included, with a methodological quality ranged from fair to high. There were statistically significant results in FOG at follow-up when comparing AO to sham intervention (SMD= -0.50, 95% CI -0.88, -0.11; I²: 0%) 3 studies, 107 participants). Interventions based on MI compared to sham intervention were statistically significant in speed at post-treatment (MD = -0.06, 95% CI -0.04, -0.08; I²: 0%) and balance at post-treatment (SMD = -0.97; 95% CI -1.79, -0.15).

Conclusions: Very low certainty of evidence was found proposing that: AO produce improvements in FOG at follow-up; and MI produce improvements in speed and balance at post-treatment.