Abstract:Objective To evaluate the difference of foot-ankle function for subjects with different foot types from both dynamic and static aspects by means of sports biomechanics, so as to provide theoretical support and references for the study of foot-ankle movement. Methods According to the arch index, 65 subjects were divided into three groups: flat foot, low arch foot and normal foot. One-way ANOVA was used to analyze the difference of static and dynamic foot-ankle function indexes among the three groups. Results In terms of static foot-ankle function, the malleolar valgus flexibility (MVF) of normal foot and ankle was significantly higher than that of low arch foot and flat foot (P<0.05), while in terms of arch height flexibility (AHF), the effect of weight bearing on normal foot was smaller than that of flat foot (P<0.05), but there was no significant difference in transverse arch flexibility (TAF) among the three groups. In terms of dynamic foot-ankle function, the force offset amplitude and time of normal foot at buffer stage were higher than those of the other two groups (P<0.05), and at transition stage, the transition time of normal foot was significantly lower than that of low arch foot and flat foot (P<0.05). At pedal-extension stage, the pedal-extension time and speed of normal foot were significantly higher than those of flat foot (P<0.05). Conclusions The posture maintenance ability and longitudinal arch shape maintenance ability of low arch foot and flat foot are worse than those of normal foot with the load increasing, and the arch rigidity and plantar elasticity of low arch foot and flat foot are worse than those of normal foot, and normal foot shows better load-bearing cushioning ability, elastic-to-rigid transition ability and pedal extension efficiency during walking. A systematic and comprehensive evaluation system is of great significance to the prediction of foot-ankle injury risk and the evaluation of sports ability.