European Journal of Applied Physiology · Jun 2, 2026
Multidimensional biomechanical modulation of walking reveals a threshold decline in distal ankle propulsion across aging
By Sangkarit N, Tapanya W
PURPOSE: This study quantified biomechanical modulation of walking using a multidimensional framework and examined its association with aging, with emphasis on distal ankle propulsion. METHODS: An open-access three-dimensional gait dataset of 240 healthy adults (18-91 years) was analyzed. Biomechanical modulation variables were defined as within-subject changes from comfortable to fast walking across spatiotemporal, kinetic, and joint-level measures. Principal component analysis (PCA) was utilized as an exploratory technique to derive composite modulation indices from a priori selected variables. Age associations were examined using linear regression and general linear models. RESULTS: Three modulation components explained 81.2% of total variance, representing global speed modulation, shock absorption, and distal ankle propulsion. Distal ankle propulsive modulation showed a significant, weak-to-moderate negative association with age (β = -0.31, R² = 0.10, p < 0.001) and a significant age-group effect (F(5,228) = 6.79, p < 0.001, partial η² = 0.13). Participants aged ≥ 70 years exhibited substantially lower distal propulsive modulation than younger groups (Δ = 1.06, 95% CI 0.84-1.28). Other modulation components showed weak or no age associations. CONCLUSION: Biomechanical modulation of walking is multidimensional and selectively affected by aging, with a pronounced threshold-like decline in distal ankle propulsion in later adulthood. Modulation-based assessment provides mechanistic insight beyond steady-state gait measures.