A Comparative Analysis of Different Longitudinal Bending Stiffness Shoes on Running Biomechanics in Adolescent Amateur Runners

Given the unique musculoskeletal characteristics, it is significant to investigate the effects of different LBS shoes on running biomechanics in adolescent runners. 12 adolescent amateur runners with rear foot strike were recruited. Each participant performed running tasks along 10 m runway at a speed of 3.3±5% m/s with three types of LBS shoes in a randomized order. The specific LSB values of shoes were 2.7 Nm/rad (low), 5.0 Nm/rad (medium) and 8.6 Nm/rad (high). Lower limb joint biomechanical data were collected and analyzed. In low LBS shoes, the results showed that the range of internal-external rotation of knee j oint and the range of inversion-eversion of ankle joint increased, which meant the ability to control knee and ankle stability reduced. In high LBS shoes, the negative work of metatarsophalangeal joint flexion-extension reduced, which helped to reduce energy consumption. However, the phenomenon of decreasing ankle peak moment and transferring ankle flexion-extension positive work to knee flexion-extension occurred. It increased energy consumption. The negative work of knee flexion-extension increased, indicating that more energy needed to be absorbed during running to cushion the impact on the knee, which bring additional burden to the lower limb musculoskeletal system. In summary, the LBS of shoes used by adolescent runners should not be high. There is an appropriate LBS between 2.7 Nm/rad (low) and 5.0 Nm/rad (medium).