Passive Ankle Dorsiflexion and Single-Leg Balance Are Independently Associated with Locomotive Syndrome Severity in Community-Dwelling Older Adults: A Cross-Sectional Study

<b>Background/Objectives</b>: Foot impairments are common in older adults, but the independent associations of specific foot indices with locomotive syndrome (LS) severity remain unclear. We examined hallux valgus angle (HV), navicular height (NH), and passive ankle dorsiflexion (ADF). <b>Methods</b>: This cross-sectional study included 119 community-dwelling older adults classified into LS stages 0-3. Bilateral measures were summarized as maximum HV and minimum NH/ADF, reflecting the worst-affected side. Proportional-odds ordinal logistic regression modeled LS stage (0-3) with foot indices and covariates (age, sex, body mass index [BMI]). Extended models additionally adjusted for Timed Up and Go (TUG), gait speed, or single-leg stance (SLS). Sensitivity analysis used binary logistic regression (LS ≥ 2 vs. <2). <b>Results</b>: Greater ADF was independently associated with lower LS severity (OR per 1°, 0.91; 95% CI, 0.85-0.98; <i>p</i> < 0.01), whereas higher BMI was associated with greater LS severity (OR per 1 kg/m², 1.15; 95% CI, 1.01-1.30; <i>p</i> < 0.05). HV and NH were not significant. After adjustment for TUG, gait speed, or SLS, ADF remained inversely associated with LS severity (ORs, 0.92-0.93; <i>p</i> < 0.05), while the BMI association was attenuated. In binary logistic regression, greater ADF was associated with lower odds of LS ≥ 2 (OR per 1°, 0.85; 95% CI, 0.76-0.94; <i>p</i> < 0.005). <b>Conclusions</b>: Reduced passive ankle dorsiflexion is independently associated with greater LS severity, robust after accounting for key mobility and balance measures. Interventions targeting ankle mobility may represent a potentially modifiable factor and warrants confirmation in longitudinal and interventional studies.