The Effect Of Heel Curve Running Shoes On Lower Limb Biomechanics During Heel-toe Running

Objective: The purpose of the study was to investigate the influence of different heel curves of running shoes on lower limb biomechanics,stability and cushion of shoes,perspective performance during heel-toe running.This study is intended to optimize the design of running shoes heel and provide theory basis for development of footwear products.Method: The heel curves of four experimental running shoe conditions were(2.5cm/2cm),(4.5cm/2cm),(2.5cm/3.5cm),(4.5cm/3.5cm)—representing y coordinate of the lateral arcing point and x coordinate of medial arcing point respectively.Subjects were 20 males among the 20 to 32 years old age group with heel-toe running pattern and they must guarantee at least 10 km running exercises per week before testing.Kinematic and kinetic data were synchronous collected by using high speed motion capture system(Vicon T20,200Hz)and force platform(AMTI-BP6009,1000Hz).Perception performance was collected by 15 cm VAS.Statistical analysis was performed using SPSS for mac(version 19.0).Shoes variable means were compared for main(p<0.05)and interaction simple effect(p<0.05)by two within participants factors repeated measures analyses of variance(ANOVA)and effect size estimation.Result: Based on biomechanics,y coordinate of the lateral arcing point had main effects on time of peak vertical force 1,ankle inversion angle at touch down,maximum ankle eversion angle.With a smaller y coordinate of the lateral arcing point,time of peak vertical force(p=0.001),ankle inversion angle at touch down(p=0.001),however,maximum ankle eversion angle was increased(p=0.013).As for x coordinate of medial arcing point,knee abduction angular impulse,maximum ankle eversion angle showed main effect on it.With a smaller x coordinate of the medial arcing point,knee abduction angular impulse(p=0.04),maximum ankle eversion angle(p=0.039)were decreased.There was an interaction effect on maximum ankle eversion angular velocity between lateral arcing point and medial arcing point.With regard to perception performance,running shoes with larger y coordinate of the lateral arcing point had poorer heel stability(p=0.041),meanwhile,these experimental shoes with bigger x coordinate of the medial arcing point showed a better transitional performance(p=0.019).Conclusion:(1)The coordinate of lateral arcing point and medial arcing point do not influence the cushion of experimental shoes.(2)The vertical coordinate of lateral arcing point has an effect on the stability of footwear,with a larger vertical coordinate of lateral arcing point,and the worse shoes stability.(3)The vertical coordinate of lateral arcing point has an effect on knee abduction moment;the horizon coordinate of medial arcing point has an effect on maximum ankle eversion angle,however,it do not influence the tibia internal rotation.