Biomechanical responses to increased longitudinal bending stiffness differ between novice and experienced runner profiles

Abstract

Carbon-plated footwear has primarily been developed and evaluated in trained or competitive runners. However, whether novice runners exhibit similar biomechanical responses to increased longitudinal bending stiffness (LBS) as experienced runners remains unclear. Therefore, the purpose of this study was to compare the acute biomechanical responses to footwear with increased LBS between novice and experienced runner profiles. Fourteen male novice and fourteen experienced runners ran at 4.17 ± 0.20 m/s in three shoe conditions: shoes without carbon plates (WCP), shoes with low longitudinal bending stiffness (LLBS), and shoes with high longitudinal bending stiffness (HLBS). Lower-limb kinematics and kinetics, as well as ground reaction forces (GRF), were analyzed using a two-way mixed-design ANOVA to assess the interactions between runner group (novice vs. experienced) and shoe condition. Significant interaction effects between runner group and shoe condition were observed across multiple lower-limb biomechanical parameters during stance. Novice runners exhibited higher peak knee extension moments and increased knee negative work. In contrast, experienced runners demonstrated greater reductions in ankle and metatarsophalangeal (MTP) range of motion (ROM) and decreased MTP negative work under higher LBS conditions. This study revealed distinct biomechanical responses to increased LBS between novice and experienced runners. Increasing LBS appeared to amplify differences in lower-limb movement strategies between runner groups, with experienced runners showing greater distal mechanical adjustments and novice runners demonstrating increased knee mechanical demand under higher LBS conditions. These findings suggest that biomechanical responses to increased LBS may differ between runner profiles and should not be assumed to be directly transferable across runners with different characteristics.