Anticipatory postural adjustments during gait initiation in people with parkinson's disease: a systematic review.

Objective: To provide an overview of alterations in anticipatory postural adjustments (APAs) during gait initiation (GI) and its possible clinical applicability in people with Parkinson's disease (pwPD).

Methods: A systematic search was conducted in PubMed and Web of Science using the terms: "Parkinson's disease" AND "postural adjustment" AND ("gait initiation" OR "step initiation"). Variables commonly used to assess APAs, including center of pressure (CoP) displacement and electromyography (EMG), were extracted. Study quality was assessed with the Newcastle-Ottawa Scale.

Results: Fourteen studies including 453 pwPD and 287 healthy subjects (HS) were reviewed. People with Parkinson's disease (PD) consistently exhibited smaller and slower CoP displacements in both anteroposterior and mediolateral directions, together with prolonged APAs durations. EMG findings indicated delayed onset and reduced amplitude, particularly in tibialis anterior and hip abductors, muscles pivotal for safe GI. Alterations were linked to disease severity and postural instability, with more pronounced changes in pwPD with freezing of gait (FoG). APAs-derived metrics showed sensitivity to subtle motor deficits even in early disease stages.

Conclusions: The reviewed literature demonstrates bradykinetic and hypokinetic APAs during GI in pwPD. GI-based measures may complement functional assessment for postural stability, gait, and fall risk, and have potential value for rehabilitation strategies such as external cueing. Levodopa improves but does not normalize APAs. Standardized, clinically feasible GI protocols are required to define meaningful thresholds and responsiveness so that APA-derived measures can be translated into routine clinical practice.