Influence Of Midfoot Running Shoe Bending Stiffness On Iomechanical And Subjective Characteristics During Running

Objective:The purpose of this study was to examine whether midfoot bending stiffness affects perception performance of running shoes, foot and ankle kinematics, and ground reaction force, providing scienticfic priciples for midfoot structure design of running footware during heel-toe running.Method:The midfoot bending stiffness of experimental running shoe condions were 0.069Nm/°,0.091Nm/° and 0.163Nm/°. Male runners with a rearfoot strike pattern, and running at least 10 Km/week, were recruited for this study. Perception performance was recorded by 15cm VAS; Kinematic and kinetic data were collected at 3.3m/s using high speed motion capture system (Vicon T20&T40,200Hz) and force platform (AMTI OR6-GT, 1000Hz) during heel-toe running. Multi segment foot model was used to find the internal movements of foot segment in the shoe.Results:Runners did not perceive any difference between the three shoe conditions for any of our perception variables. Based on kinematic and kinetic tests, the stiff midfoot shoe provoked delayed the appearances of peak vertical force 1 and peak vertical trough, bigger initial foot dorsiflexion and ankle inversion angle, higher maximum braking rearfoot plantarflexion velocity; lower forefoot maximum propulsion plantarflexion relative to the midfoot, and smaller range of motion of forefoot relative to rearfoot and midfoot in frontal plane.Conclusion:Midfoot bending stiffness cannot effect perception performance of running shoes. But it has influence on propulsion velocity and braking plantarflexion velocity:the flexible midfoot shoe show faster propulsion velocity; the stiff midfoot shoe expressed faster braking plantarflexion velocity. The increased stiffness of midfoot increased the stability of foot segments movement during running.