Gait instability and compensatory mechanisms in Parkinson's disease with camptocormia: An exploratory study

Camptocormia has been considered to contribute to vertical gait instability and, at times, may also lead to forward instability in experimental settings in Parkinson's disease (PD). However, these aspects, along with compensatory mechanisms, remain largely unexplored. This study comprehensively investigated gait instability and compensatory strategies in PD patients with camptocormia (PD+CC). Ten PD+CC, 30 without camptocormia (PD-CC), and 27 healthy controls (HCs) participated. Self-paced gait tasks were analyzed using three-dimensional motion capture systems to assess gait stability, spatiotemporal, and kinematic parameters. Unique cases with pronounced forward gait stability or instability were first identified, followed by group comparisons. Correlation analysis was performed to examine associations between trunk flexion angles (lower/upper) and gait parameters. Significance level was set at 0.05. Excluding one unique case, the PD+CC group showed a significantly lower vertical center of mass (COM) position (p=0.019), along with increased mediolateral COM velocity (p=0.004) and step width (p=0.013), compared to PD-CC group. Both PD groups showed higher anterior-posterior margin of stability than HCs (p