Effect Of Impact Force And Lower Limb Biomechanics During A 12-weeks Posture Control Intervention In Runners

purpose: To explore the Effect of impact force and lower limb biomechanics during a 12-weeks posture control intervention in runners.Methods:The 3D kinematics/Kistler force plates were used to collect sagittal plane kinematics and ground reaction force data synchronously of a total of 17 male runners under pre-and post-posture control intervention in minimalist and convention shoes.Compare the data of ground reaction force,joint angle/moment/power,and leg stiffness before and after fatigue.Results:1)For GRF,there was no significant difference in the impact between shoe conditions before training,but CS significantly reduced the maximum load rate,while delaying the first and second peaks and the total contact time.2)For kinematics,after training,the foot contact angle of the experimental group decreased significantly,the angle of plantarflexion increased,and the velocity of hip extension increased.The foot contact angle increased in CS.In the control group,the angle of plantarflexion increased,and the velocity of hip increased.3)For Kinetic,the knee moment and hip power decreased in the experimental group and the control group,and the ankle moment increased in the experimental group.After training,the leg stiffness increased in both groups and decreased significantly when wearing CS.Conclusion:A 12-week posturecontrol training program with minimalist shoes could effectively convert non-forefoot strike runners who used to wear cushioned shoes to forefoot strike,showing that 7 out of 9 people in the experimental group converted to forefoot strike(78 %).Using only minimalist shoes for training instead of running posture may increase the load rate and increase the risk of injury.In addition,the characteristics of forepaw contact with the ground after training are continued when wearing sports shoes,the specific performance is the ankle when touching the ground,the front of the foot first touch the ground,and because of the structure and materials of the sports shoes,after training,the runner’s kinematic and kinetic effects,such as training changes to the forepaw contact with the ground,although the participants will remain in the sports shoes,but the foot touch angle will increase.After training,the way of touching the ground changed,ankle torque increased,the strength of the calf triceps increased,it is recommended to exercise carefully.