Influence of Shoe Midsole Bending Stiffness on Comfort and Sprinting Performance

Objective:The purpose of this study was to investigate the influence of shoe midsole bending stiffness on comfort and sprinting performance and the potential mechanism.Methods: Twelve male sprinter participated in the study, three pair of running shoes with different mid- sole bending stiffness were used.Plantar loading, joint energy and muscular activity of lower extremity during running of each type of shoes were collected and analyzed.The perceived com- fort was recorded by 150mm VAS.Results:The lower stiffness shoe showed higher perceived comfort rating in terms of forefoot cushioning, dorsal comfort and overall comfort compared with medium and higher stiffness shoe.The lower stiffness shoe recorded lower peak plantar pressure in the lateral and medial side of the forefoot.The higher stiffness shoe faster than the other two shoes in averaged velocity.In joint energetics, only lower stiffness shoe reduced the amount of energy lost at metatarsophalangeal joint during running compared with the other two shoes.Finally, there is no significant difference in RMS of rectus femoris, biceps femoris, tibia- lis anterior and lateral gastrocnemius in the stance phase of running.Conclusion:Lower midsole bending stiffness shoes can help wearer obtain better comfort.Increasing midsole bending stiff- ness of shoes in a way can increase sprinting performance.Reducing the amount of energy lost at the metatarsophalangeal joint may resulted in a corresponding improvement of sprinting per- formance.