Abstract

Background: Parkinson’s disease (PD) impairs sit-to-stand performance due to bradykinesia and postural instability; however, specific movement strategies and anticipatory momentum transfer adjustments (AMTA) remain unclear. Markerless motion capture offers an accessible alternative to quantify kinematics. This study compared sit-to-stand strategies and AMTA between individuals with PD and healthy controls, and evaluated their correlation with clinical assessments.
Methods: Fifteen individuals with PD and 15 healthy controls performed a self-selected sit-to-stand (STS) test and the five-times sit-to-stand test (FTSST). Movements of the head, trunk, hip, knee, and ankle were recorded using markerless motion capture across four STS phases and the FTSST momentum transfer phase. Clinical assessments included the Mini-Balance Evaluation Systems Test (Mini-BESTest), Falls Efficacy Scale-International (FES-I), and the Movement Disorders Society–Unified Parkinson’s Disease Rating Scale motor examination (MDS-UPDRS Part III).
Results: The PD group required more time to complete both tasks compared to controls (all adjusted p < 0.050). During the self-selected STS, individuals with PD exhibited earlier onset of head and trunk movement during Phase I (Flexion Momentum) and lower peak angular extension velocities of the head, hip, and knee during Phase III (Extension) (all adjusted p < 0.050). No between-group differences were observed in postural sway during Phase IV (Stabilization) (all adjusted p > 0.050). During the FTSST, the PD group demonstrated longer durations for the AMTA1 and AMTA2 sub-phases (adjusted p = 0.037). No other kinematic differences remained significant after correction for multiple comparisons (all adjusted p > 0.050). Correlation analyses revealed low-to-moderate associations (|r| = 0.365 to 0.635, p < 0.050) between clinical outcomes (Mini-BESTest scores and MDS-UPDRS Part III) and kinematic parameters.
Conclusion: Individuals with PD exhibit disease-specific sit-to-stand compensation characterized by early head and trunk initiation. During the FTSST, momentum transfer relies primarily on trunk extension rather than lower limb extension. These findings highlight altered anticipatory and segmental coordination strategies in PD, which are detectable using markerless motion capture.