Background and Purpose: Understanding the contribution of anticipatory postural adjustments (APA) on walking ability in individuals with Huntington's disease (HD) may provide insight into motor planning and the functional consequences of HD-specific cortical-basal ganglia pathway dysfunctions. The purpose of this study was to evaluate inertial measurement unit (IMU)-derived measures of APAs and first step parameters, and their contribution to gait speed, in individuals with and without manifest HD during a single-task and cognitive load condition.
Methods: 33 individuals with manifest HD and 15 age-matched healthy controls wore three Opal APDM IMUs during a 14-meter walk during a single task and cognitive load condition. APA acceleration amplitudes, APA durations, first step range of motion (ROMs), and first step duration were compared, along with their relationship to gait speed.
Results: Individuals with HD had significantly greater APA acceleration amplitudes, smaller first step ROMs and longer first step durations compared to healthy controls. No difference in APA durations were present between groups across conditions. Linear model results and significant correlations between mediolateral APA acceleration amplitudes and APA durations were found.
Conclusions: Larger acceleration amplitudes, smaller first step ROMs of greater duration, accompanied by the preservation of APA durations reveal a discrepancy in movement scaling in HD. Additionally, the mediolateral component of the APA is likely a rate-limiting factor that drives a compensatory response in gait initiation. Additional research is needed to explore the neural correlates of HD-related movement scaling.
How many gait initiation trials are necessary to reliably detect anticipatory postural adjustments and first step characteristics in healthy elderly and people with Parkinson’s disease?
