The impact of running experience and shoe longitudinal bending stiffness on lower extremity biomechanics: a cross-sectional study.

Purpose: The impact of shoe stiffness on running biomechanics is well-documented, while the specific effect on the performance of biomechanically distinct groups such as novice runners and experienced runners is still largely unexplored. The study aimed to evaluate the biomechanical effect of different shoe longitudinal bending stiffness on the lower limb during running in novice runners and experienced runners. Methods: Twelve experienced runners and ten novice runners ran at a speed of 4.47 m/s while randomly wearing shoes with either low stiffness (5.9 Nm/rad) or high stiffness (8.6 Nm/rad). An Opensim musculoskeletal model was adopted for estimating lower limb joint angles, joint angular velocities, joint moment, joint work, peak joint reaction forces during running stance phase. Results: Results showed that novice runners displayed greater lower limb joint angles and less joint moment, while experienced runners exhibited reduced joint angles but greater joint moment, and higher peak joint reaction forces were observed at the knee and ankle joints. Furthermore, increased shoe longitudinal bending stiffness resulted in higher peak joint reaction forces at the metatarsophalangeal joint for novice runners while lower for experienced runners. Conclusions: Novice runners exhibit greater lower limb joint angles and reduced joint moments compared to experienced runners. Increased longitudinal bending stiffness results in higher peak joint reaction forces at the metatarsophalangeal joint for novice runners, while experienced runners show reduced forces under the same conditions. This nuanced understanding of joint dynamics underscores the need for tailored training and footwear recommendations specific to different levels of running experience.