2026 Volume 11 Article ID: 20260062
Objectives: This study examined associations between lumbar anterior trunk flexion (ATF) and mobility outcomes in Parkinson’s disease (PD).
Methods: We conducted a cross-sectional study of 50 participants with PD. ATF was measured in relaxed standing (static ATF) and during maximal trunk extension; postural reversibility (ΔATF) was defined as static minus extended ATF. Outcomes included 10-m walk speed and Timed Up-and-Go (TUG) test result; TUG time was also natural log-transformed (lnTUG). Associations were assessed using correlations and covariate-adjusted linear regression models. Twelve-month fall history was analyzed using logistic regression.
Results: The statistical significance of the static ATF–lnTUG association was sensitive to exclusion of one potentially influential observation (all participants with lnTUG data: n = 42, standardized β = 0.278, P = 0.060; after exclusion: n = 41, ΔR2 = 0.113, P = 0.010; standardized β = 0.36, P = 0.010). ΔATF did not improve model fit (P = 0.985). Neither static ATF nor ΔATF was associated with 10-m walk speed in the complete-case multivariable model (n = 34). Fall history was available for 42 participants (8 missing); the static ATF–fall history association did not reach statistical significance (odds ratio: 1.047 per 1° increase, 95% confidence interval: 0.998–1.098; P = 0.061).
Conclusions: Greater static ATF tended to be associated with longer lnTUG but not with 10-m walk speed; the lnTUG finding was sensitive to exclusion of one potentially influential observation. ΔATF showed limited incremental explanatory value beyond static ATF and remained an exploratory measure of postural reversibility.
