Influence Of Shoe Bending Stiffness On Running Economy And Biomechanical Mechanism Of Lower Extremity During Running

Objective: The purpose of this study was to investigate the influence of shoe bending stiffness on running economy and joint work of lower extremity,and the potential mechanism.Methods: Five shoes with different bending stiffness were made through modifying the density and depth of grooves on midsole,at the same time the midsole material were not changed.All shoes were chosen size EUR41.Eleven male running enthusiasts participated in this study.Firstly subjects performed a maximal aerobic power test.The purpose of the test was to determine each subject’s anaerobic threshold.All tests done on the treadmill,and the measurement of oxygen consumption was calculated every 30 s using Cortex Metalyzer 3B.The running economy test used the speed which was equivalent to the workload(0.8km/h)below the anaerobic threshold.One week later is the running economy test.A single running economy test was 6 min long and the last 2 min were used for analysis.Shoes were assigned in a blinded.After one week,subjects performed in each of the five footwear conditions.Kinematic and kinetic data were simultaneously collected during each trial.A one-way repeated-measures ANOVA was used to compare mean differences in metabolic cost,joint energy,and kinematic values for all the conditions.The level of significance was set at α=0.05.Results: The effect of shoe bending stiffness on running economy and metatarsophalangeal joint work were significant,and there was no difference in joint work for hip,knee,and ankle joint.The O2 consumption and metatarsophalangeal joint work of shoe C were the lowest and shoe A and E’s were higher.Conclusions: The effect of shoe bending stiffness on running economy and metatarsophalangeal joint work showed a inverted “U-shaped” curve.A appropriate bending stiffness can reduce the metatarsophalangeal joint work and improve the running economy.The effect of shoe bending stiffness on metatarsophalangeal joint work may be the mechanism for the effect on running economy.