Effects of Mild Impairment in Parkinson’s Disease on Balance Control
Author(s): Giovanna Machado, Douglas Russo-Junior, Flávia Doná, José Barela, Henrique Ferraz, Sonia Silva, Ana Barela
Objective: The aim of this study was to examine the effects of mild impairment of PD on propulsion and balance control during gait initiation.
Design: Retrospective study.
Setting: University research laboratory.
Methods: This study included 15 individuals with PD (59.7 ± 6.8 years) and 15 individuals matched by age (59.8 ± 6.5 years) and sex with no known orthopedic or neurologic impairment that could compromise gait (control). Participants were instructed to stand quietly, looking straight ahead with their arms hanging at their sides. After a verbal command, they walked towards the end of a walkway at a comfortable speed without interruption. Center of mass (CoM) and center of pressure (CoP) in the medial-lateral (ML) and anterior-posterior (AP) directions, horizontal impulses of each limb, and the distance between CoM and CoP at specific events were obtained.
Results: Individuals with PD exhibited reduced impulse in both limbs and directions and reduced CoM-CoP distance at most events compared with controls. Although no group difference was found in the CoM trajectory length, individuals with PD exhibited shorter CoP trajectory lengths compared to controls.
Conclusion: These results suggest that PD compromises balance control, even in individuals with mild impairment, reducing the CoP trajectory length and propulsion during gait initiation. Intervention protocols for these individuals should emphasize CoP transferences to reduce postural control deficit.