The Effect Of Site Material On The Risk Of Anterior Cruciate Ligament Injury In Female Football Players During Side Cutting

Purpose: In order to explore the biomechanical characteristics of female football players during side cutting movement on the natural turf,artificial turf and indoor hard ground,through kinematic and electromyographic analysis,this study aims to understand whether the site material can affect the risk of ACL injury during side cutting,so as to reduce and prevent the occurrence of such sports injuries.Method:The subjects are 20 women football players from the college of physical education of Hangzhou Normal University(age: 21.15±1.5 years old,height: 166±4.96 cm,mass:57.5±6.04 kg,experience: 5.95±1.64 years).Two JVC high-speed cameras(200frames / second)were used for capturing,and the surface electromyography analysis system(1000 Hz)was used to record the EMG signal during side cutting.The joint angles were calculated by Kwon 3D analysis software,and the EMG signal was processed by Mege Win software.Statistical analysis of repeated measure variance in SPSS 21 was used to compare the main influence and interaction of site material and cutting angle on side cutting.The significance level was set to be less than 0.05.Result: The flexion angle of knee joint was larger when cutting on the hard ground,which was 32.7±5.4°,and they were 31.5±4.9°and 29.5±4.3°for artificial and natural turf,respectively.On the sagittal plane,the flexion angle of hip joint and knee joint were affected by both the site material and the side cutting angle at the moment when the whole foot touched the ground(the site material p = 0.024,the cutting angle p =0.020).The knee joint on the frontal plane showed the tendency to valgus.The knee valgus angle reached the highest moment when the whole foot touched the ground.Knee valgus angle was greater than turf when cutting on the hard ground,and there was no difference between artificial and natural turf.The knee valgus angle was mainly affected by the cutting angle(p = 0.000)rather than the site material.The quadriceps femoris was the main muscle group for cutting movement,and the gastrocnemius muscle was also activated to some extent.Conclusion: There was no interaction between site material and cutting angle on the mechanical characteristics of ACL during side cutting.There was no difference in the injury risk of ACL betweenthe side cutting on artificial turf and natural turf,while the side cutting on turf may increase the injury risk of ACL than hard ground.The risk of ACL injury was probably higher in 90°side cutting than 45°.Quadriceps femoris was the dominant muscle in cutting movement,and the site material and cutting angle didn't affect the activation of lower limb muscles.