Study On Motion Characteristics Of Side-cut Between Male Soccer Players And Recreational Soccer Player

Purpose:To explore the dynamic and kinematic characteristics and differences of middle and lower extremities between Chinese college male football players and recreational football player of the same age.Through the comparison of the lateral cutting movements of the bilateral lower limbs,the differences of lower limb dynamics and kinematics between the dominant side and the non-dominant side were analyzed.Methods:12 male football players and 12 male recreational football player were tested with 45° side-cutting test and 90° side-cutting test to the left and right,and the kinematic and dynamic indexes of the subjects were collected and compared.Results:(1)The differences of hip flexion angle and knee flexion angle between players and recreational football players were statistically significant(P<0.05).Recreational footballers showed larger knee flexion angle and larger hip flexion angle.(2)There were significant differences in hip flexion angle,hip abduction angle,knee flexion angle,knee valgus moment and knee rotation moment between 45° side-cutting direction and 90° side-cutting direction(P<0.05).The 90°side-cutting direction has smaller hip flexion angle,knee flexion angle and larger hip abduction angle,knee valgus moment and knee rotation moment.(3)The differences of hip flexion angle,hip abduction angle,knee rotation angle,knee rotation torque and gastrocnemius contractile force were statistically significant(P<0.01).Changing to the right,that is,the non-dominant lateral support shows larger knee flexion angle,smaller hip abduction angle,knee rotation angle and knee rotation torque,and the contractile force of gastrocnemius muscle is less.(4)The hamstring contractile force had the interaction of exercise grade and changing direction.Compared with the group,the recreational group showed less hamstring contractile force when changing to the right(P<0.01).The non-dominant side of the recreational group showed smaller hamstring contraction(P<0.05).(5)There was an interaction between knee varus angle and knee varus angle.When the knee varus angle was 45°,the knee varus angle was smaller when the right direction was changed(P<0.05),and the knee varus angle was also smaller when the knee varus angle was changed to the right(P<0.05).Conclusion:(1)Compared with recreational football players,male footballers face the risk of ACL injury because of their smaller hip and knee flexion angle at the peak of the ground reaction force of side-cutting movement.(2)Compared with footballers,male recreational footballers face the risk of ACL damage due to insufficient contraction of the popliteal chordae muscle on the non-dominant side at the peak of the ground reaction force in the side-cutting movement.(3)Compared with 45°sidecutting direction,90°side-cutting of male football players and recreational football player has larger hip abduction angle,smaller hip flexion angle and knee flexion angle,and 90°smaller knee flexion angle may make 90°side-cutting face greater risk of ACL injury.(4)Non-dominant side-cutting of male football players and recreational football player has smaller hip abduction,knee external rotation angle,knee external rotation torque and gastrocnemius contractile force,which makes the non-dominant side face a greater risk of ACL injury.