Gait Adaptations in Step Length and Push-off Force during Walking with Functional Asymmetry

Human walking is remarkably adaptable, allowing individuals to maintain efficiency and stability across diverse conditions. This study investigates how healthy young adults adapt step length and push-off force to varying speeds and cadences under functional asymmetry induced by a unilateral knee constraint, simulating hemiparetic gait. A dataset of 19 participants walking across 30 conditions was used to examine these adaptations in both absolute terms and symmetry metrics. Results reveal that functional asymmetry disproportionately impacts propulsion, with constrained-leg force decreasing significantly at higher speeds. Step length symmetry remains stable, suggesting a prioritisation of spatial over kinetic symmetry, likely to optimise walking energetics and maintain anterior-posterior balance. Statistical models demonstrated good within-dataset performance but limited generalisability in cross-dataset predictions, where differences in population cohorts and experimental designs reduced accuracy. These findings provide insights into the mechanisms driving gait adaptations and highlight critical limitations in applying statistical models to patient populations, underscoring the importance of representative datasets and caution when extrapolating findings across populations.