Sport Biomechanics Analysis Of Tai Chi Ye Ma Fen Zong Practice Resulting In Knee Joint Pain

Objective: to obtain the risk factors of knee pain in Taichi exercisers by biomechanical researchMethod : Using the Motion Analysis Raptor-4(USA)to collect the kinematic parameters of the body during the movement of parting the wild horse's mane.DELSYS Trigon-Mobile(USA)was used to collect the EMG signals and the MVC of each muscle during movements.Four ergographs were used to collect the dynamic parameters of the lower extremities,using the Motion Analysis Raptor-4,DELSYS Trigon-Mobile and ergographs.Results: 1)The knee joint adduction angle of the experimental group was significantly greater than that of the expert group(p=0.034),the torso rotation angle of the expert group was significantly larger than that of the experimental group(p =0.002),and there was no significant difference in the other angles(p> 0.050)at the time of single leg support.2)The knee joint adduction angle(p=0.043)and the internal rotation angle(p=0.016)of the experimental group was significantly greater than that of the expert group at the time of right leg squatting and left leg forward to open half a minute away from the moment.There was no significant difference in the other angles(p> 0.050).In the experimental group,all 15 individuals presented with an early appearance of the torso going forward to the leg,which was significantly different from that of the expert group(p = 0.030).3)The knee joint internal rotation angle of the experimental group was significantly greater than that of the expert group at the time of right leg squatting and the left leg on the ground(p=0.005).All the 15 individuals in the experimental group showed a positiveappearance of the legs going forward to the trunk,which was significantly different from that of the expert group(p = 0.020).4)The maximum amplitudes of tibialis anterior muscle(p = 0.025)and gluteus maximus(p = 0.019)in the expert group were significantly greater than those in the experimental group,with no significant difference in other muscles(p> 0.050).The myoelectricity of the rectus femoris muscle in the expert group was significantly greater than In the experimental group(p= 0.000),the myoelectricity of the lateral femoral head muscle in the experimental group was significantly greater than that in the expert group(p = 0.001),while the rest had no significant difference(p> 0.050).Conclusion: 1)there are two abnormal knee movements in the subjects who had knee pain while playing Taichi.The experimental group was divided into two groups according to the error of the action: one with the movement of knee-twisting and one without such movement but the amplitude of muscle activation was abnormal.2)During the movement of parting the wild horse's mane,the cause of knee pain in the knee exerciser at the time of striding is the internal rotation of the thigh,while the calf is in external rotation which correspondingly makes the patella externally rotated.3)However,there is still an early trunk turning and over abduction of the thighs in those Taichi exercisers who don't have a twisted knee in the movement,leading to a higher muscle activation amplitude in the vastus lateralis than the vastus medialis,and a larger Q angle of the knee joint and external displacement of the patella as a result.The two cases of abnormal patella movement are consistent with the patella movement during patellar syndrome.So,we can come to the conclusion that the cause of pain in Taichi sport is Patellofemoral Syndrome.