Biomechanical mechanisms underlying the effect of minimalist footwear on walking stability in persons with a history of falls.

BACKGROUND: Footwear design influences sensory input and motor control during gait-key factors in fall risk among older adults. Our previous work showed that minimalist footwear alters walking stability in individuals with a history of falls, but the underlying biomechanical mechanisms remain unclear. Here, we investigated how footwear type influences lower-limb biomechanics, whether these effects are altered by cognitive load, and whether they mediate adaptations in gait stability. METHODS: In this cross-sectional repeated-measures design, thirty older adults with a history of falls (mean ± SD age 68.6 ± 4.4 years) completed walking trials under three footwear types (barefoot, supportive, minimalist) and two task conditions (single and dual-task with cognitive load). 3D kinematics, ground reaction forces, and surface electromyography were collected to quantify joint angles, powers, and muscle activity. Statistical parametric mapping and linear mixed models tested condition effects and cognitive load interactions, while mediation analysis assessed whether biomechanical changes explain previously reported stability differences. RESULTS: Here we show that minimalist shoes induce distinct biomechanical adaptations, including greater ankle dorsiflexion and external rotation, reduced hip flexion during stance, and increased knee flexion during swing. They also enhance hip and ankle joint power generation and elicit higher activity in rectus femoris and vastus lateralis. These effects are consistent across cognitive conditions. Hip kinematics, kinetics, and quadriceps muscle activity mediated adaptations in gait stability observed with minimalist footwear. CONCLUSIONS: These findings identify specific neuromuscular changes associated with minimalist footwear that may explain adaptations in walking stability. Our results support the development of footwear-based interventions for fall prevention in older adults and highlights the need for randomized controlled trials in broader populations to confirm causality.