Biomechanical Characteristics Of The Ankle Joint During Exercise In Male University Students With Flat Feet

Objective:Flatfoot is a common postural deformity of the foot,characterized by the collapse or disappearance of the medial arch,which not only affects the support and propulsion functions in gait,but may also be associated with knee pain,plantar fasciitis,and other injuries.In this study,we collected kinematic and kinetic data of the ankle joint during exercise between flatfoot and normal foot by walking and jogging tests,and compared and analyzed the ankle joint angle,joint moment and ground reaction force to summarize the gait characteristics of the ankle joint during exercise in people with flatfoot and Provide theory for more targeted treatment and exercise guidance for flatfoot populations.Methods:The subjects were 34 male university students(17 with normal feet and 17 with flat feet).Firstly,during walking(3km/h)and jogging(8km/h),the 3D motion capture system was used to test the joint angle changes of the ankle joint between the flat foot and normal foot during exercise,and the ankle joint moments and ground reaction force parameters in each direction were recorded from the force measurement table system..A sample t-test was used for all data,and an independent sample t-test was used for statistical analysis between groups.Results:(1)The moment the foot followed the ground during walking:the ankle joint angle x-axis and z-axis changes were significantly different(P<0.05),and the flat foot valgus and external rotation angles were greater than normal feet;the joint moment z-axis changes were significantly different(P<0.05),and the flat foot internal rotation moment was greater than normal feet;the ground reaction y-axis changes were significantly different(P<0.05),and the inward ground reaction force of the flat foot ankle joint was greater than normal feet.The inward ground reaction force of the flat foot was greater than that of the normal foot.(2)The maximum moment of ground reaction force:the change of ankle joint angle x-axis had a significant difference(P<0.05),and the valgus angle of flat foot was greater than that of normal foot.There was a significant difference(P<0.05)in the change of ankle joint moment x-axis,y-axis and z-axis changes,and the inversion,plantarflexion and internal rotation moment of flat foot was greater than that of normal foot.The ankle joint ground reaction x-axis and y-axis changes were significantly different(P<0.05),and the inward ground reaction force of the flat foot was greater than that of the normal foot,while the forward ground reaction force was less than that of the normal foot.(3)Toe off the ground instant:the ankle joint angle x-axis,y-axis and z-axis changes were significantly different(P<0.05),and the flatfoot valgus and external rotation angles were greater than normal foot,while the plantarflexion angle was less than normal foot.The ankle joint moment x-axis,y-axis and z-axis changes were significantly different(P<0.05),and the inversion,plantarflexion and internal rotation moments of the flat foot were greater than those of the normal foot.The ankle joint ground reaction x-axis and y-axis changes were significantly different(P<0.05),and the forward ground reaction force of flat foot was smaller than that of normal foot.The inward ground reaction force was greater than that of the normal foot.(4)The moment the foot followed the ground during jogging:there were significant differences in the changes of ankle joint angle x-axis,y-axis and z-axis(P<0.05),and the flat foot valgus,external rotation and dorsiflexion angle were greater than normal foot;there were significant differences in the changes of ankle joint moment x-axis and y-axis(P<0.05),and the flat foot valgus and dorsiflexion moment were greater than normal foot;there were significant differences in the changes of ankle joint ground reaction y-axis(P<0.05),and the ground reaction force inward of flat foot was greater than that of normal foot.(5)Moment of maximum ground reaction force:ankle joint angle x-axis and y-axis changes were significantly different(P<0.05),and the valgus angle of flat foot was greater than that of normal foot,while the plantarflexion angle was less than that of normal foot.There were significant differences(P<0.05)in the y-axis and z-axis changes in joint moments,and the plantarflexion and internal rotation moments were greater in the flat foot than in the normal foot;there were significant differences(P<0.05)in the x-axis and y-axis changes in ground reaction,and the inward ground reaction force in the flat foot was greater than in the normal foot,while the forward ground reaction force was less than in the normal foot.(6)Toe off the ground instant:the ankle joint angle x-axis,y-axis and z-axis changes were significantly different(P<0.05),the flat foot valgus and external rotation angle were greater than normal foot,while the plantarflexion angle was less than normal foot;the ankle joint moment x-axis and y-axis changes were significantly different(P<0.05),the flat foot valgus moment was greater than normal foot,and the plantarflexion moment was less than normal foot.The ankle joint ground reaction x-axis and y-axis changes were significantly different(P<0.05),and the forward ground reaction force of the flat foot was smaller than that of the normal foot,and the inward ground reaction force was also larger than that of the normal foot.(7)The two groups of subjects showed significant differences in foot rotation angle during walking and jogging(p<0.05),and the foot rotation angle of flat feet was greater than that of normal feet.Conclusions:(1)During walking and jogging,flat feet exhibit valgus and external rotation of the foot,and the changes in plantar structure put the plantar fascia under greater stress,leading to an increased risk of injury.(2)People with flat feet improve lower limb stability during walking and jogging by increasing the internal rotation and inward moment,and improve the ability to stirrups by increasing the plantarflexion moment.(3)The inward ground reaction force of flat feet is greater than that of normal feet,which increases the ankle joint shear force and makes the medial ligament injury more likely to occur during exercise.The forward ground reaction force was less than that of the normal foot,indicating that the abnormal foot structure had an effect on the ability of the flat foot to strike the ground.(4)In jogging,the flat foot follows the ground instantly by increasing the ankle dorsiflexion angle to improve the cushioning ability when landing.