Stress characteristics of the main joints of femur and lower limb bones of Tai Chi with different steps based on Anybody simulation
BACKGROUND:Anybody musculoskeletal modeling system uses mathematical modeling techniques to simulate the relationship between human bones,muscles,and the environment,allowing for the study of inverse dynamics of the human body and obtaining indicators such as lower limb joint forces.OBJECTIVE:To analyze the stress distribution patterns of lower limb joints during the practice of Tai Chi movements,thereby exploring the scientific training and exercise value of Tai Chi.METHODS:Eight Tai Chi master-level athletes were selected from the Wushu College of Beijing Sport University for data collection,including seven sets of stepping movements and CT scans of the right femur.The BTS infrared capture system and Kistler three-dimensional force platform were used to collect kinematic and mechanical data of the seven sets of stepping movements in Tai Chi(Eight Methods and Five Steps).The Anybody 7.2 musculoskeletal model's multi-body dynamics simulation technology was utilized to calculate lower limb joint dynamic parameters,and Workbench 19.2 was used to perform stress analysis on the femur.RESULTS AND CONCLUSION:(1)Using Workbench software,the stress results of the femur for seven sets of movements were obtained.The peak stress values of the seven sets of movements in descending order were:Retreat and Rollback(22.00 MPa),Retreat and Pluck(19.379 MPa),Left and Right Shift Step Squeeze and Press(9.35 MPa),Left and Right Shift Step Elbow Lean(6.30 MPa),Forward Step and Expand(4.68 MPa),Forward Step and Pull(2.57 MPa),and Middle Fixed Standalone Position(0.31 MPa).(2)In the seven sets of stepping movements,the two backward stepping movements resulted in the greatest stress on the femur(P<0.05),and the maximum stress positions on the femur were different during the movement of the seven sets of actions.(3)It is concluded that during the seven sets of stepping movements in Tai Chi(Eight Methods and Five Steps),stress threshold and maximum stress position of the femur will vary with different movements in five directions(seven sets of movements).Continuous training can comprehensively stimulate the femoral body.Forward stepping movements have a greater impact on the front and upper lateral side of the femoral body,while backward stepping movements have a greater impact on the back and inner side of the femoral body.Left and right lateral stepping movements mainly involve symmetrical stress on both sides of the femoral body.(4)Beginners should train targeted according to the stress characteristics of different stepping movements.During forward and backward stepping movements,attention should be paid to the rotational force of Tai Chi,and during left and right lateral stepping movements,attention should be paid to the medial counterforce.Beginners should focus on the Tai Chi training steps that correspond to their own weaknesses to achieve better exercise outcomes.
Tai Chieight methods and five stepsfemurAnybody musculoskeletal modelfinite element analysisbiomechanicsjoint stresslower limb bone