摘　要

研究目的：

蹬跨步作为羽毛球基础步伐是造成膝关节损伤的常见动作之一。大量研究表明，蹬跨步方向是造成膝关节损伤的重要因素，但对不同蹬跨步方向下的膝关节内部结构受力特征研究较少，尚未明确蹬跨步方向导致膝关节损伤的具体机制。因此，本研究采用生物力学手段和有限元分析方法，对不同方向蹬跨步动作下的膝关节进行分析，旨在探讨不同方向蹬跨步下膝关节的生物力学特征及内部结构的冲击损伤机制。以期为预防羽毛球运动膝关节损伤提供一定的理论支撑，为日常羽毛球训练提供理论指导。

研究方法：

本研究招募15名北京师范大学体育与运动学院羽毛球专项男性大学生参与运动测试。利用Vicon红外运动捕捉系统采集运动学数据，利用一块Kistler力台同步采集动力学数据。将结果导入Visual 3D软件进行分析。研究选取一名健康受试者，对其进行无负重下仰卧状态的右侧膝关节CT及MRI扫描，将所得结果导入Mimics19.0 进行分割平滑得到几何模型，利用Geomagic 2014 进行平滑处理与逆向处理建立实体模型，利用Hypermesh14.0 进行前处理包括各个结构的网格划分，将结果导入Abaqus2020进行后处理包括材料属性设定等。采用胫骨关节接触面积和接触应力峰值与前人研究结果进行比较，验证本模型的有效性。通过加载载荷分析膝关节内部组织应力应变特征。

研究结果：

运动学数据结果：

第二动作时相内地反力峰值时刻膝关节角度：左前蹬跨步的膝关节屈曲角度为－64.22±10.08°，右前蹬跨步的膝关节屈曲角度为－69.67±13.60°，两者不存在任务间的统计学差异（P=0.275）。左前蹬跨步的膝关节内翻角度为－4.12±3.22°，右前蹬跨步的膝关节内翻角度为－21.3.1±4.77°，两者存在任务间的统计学差异（P＜0.05）。左前蹬跨步的膝关节外旋角度为15.64±7.08°，右前蹬跨步的膝关节内旋角度为－27.21±7.55°，两者存在任务间的统计学差异（P＜0.05）。

2.动力学数据结果：

（1）第二动作时相内地反力峰值时刻膝关节反作用力：左前蹬跨步的膝关节水平反作用力为－1.66±2.42 N/Kg，右前蹬跨步的膝关节水平反作用力为－4.27±3.24 N/Kg，两者存在任务间的统计学差异（P＜0.05）。左前蹬跨步的膝关节剪切力为9.22±6.68 N/Kg，右前蹬跨步的膝关节剪切力为9.64±5.97 N/Kg，两者不存在任务间的统计学差异（P =0.688）。地反力峰值时刻左前蹬跨步的膝关节垂直反作用力为2.77±7.13 N/Kg，右前蹬跨步的膝关节垂直反作用力为2.61±5.26 N/Kg，两者不存在任务间的统计学差异（P =0.325）。

（2）第二动作时相内地反力峰值时刻膝关节力矩：左前蹬跨步的膝关节屈曲力矩为－2.43±0.78 N*M，右前蹬跨步的膝关节伸展力矩为0.35±0.50 N*M，两者存在任务间的统计学差异（P＜0.05）。地反力峰值时刻左前蹬跨步的膝关节内翻力矩为－0.20±0.16 N*M，右前蹬跨步的膝关节内翻力矩为－0.5±0.25 N*M，两者存在任务间的统计学差异（P＜0.05）。地反力峰值时刻左前蹬跨步的膝关节外旋力矩为0.15±0.19 N*M，右前蹬跨步的膝关节内旋力矩为－0.73±0.31 N*M，两者存在任务间的统计学差异（P＜0.05）。

3. 有限元分析结果：

左前方向蹬跨步第二时相髌骨软骨、外侧胫骨软骨、股骨软骨和半月板在地面反作用力峰值时刻的应力与接触应力结果分别为：1.86MPa、2.20 MPa；6.09MPa、2.48 MPa；1.29MPa、5.80 MPa；3.52MPa、5.45 MPa。右前蹬跨步第二时相髌骨软骨、外侧胫骨软骨、股骨软骨和半月板在地面反作用力峰值时刻的应力结果分别为： 9.13MPa、3.815 MPa；6.09MPa、2.97 MPa；1.47MPa、7.37 MPa；4.17MPa、6.85 MPa。

研究结论：

1．右前方向蹬跨步的膝关节有着更大的活动范围；右前方向蹬跨步膝关节的内翻与内旋峰值角度显著的大于左前方向蹬跨步，但膝关节屈曲峰值角度小于左前蹬跨步；

２．蹬跨步击球时相中，右前方向蹬跨步将导致更大的膝关节内侧反作用力与屈曲、内翻、内旋力矩，右前方向蹬跨步可能会导致更大的膝关节损伤风险。

３．有限元模型加载载荷中显示，右前方向蹬跨步显著高于左前方向蹬跨步、外侧胫骨软骨、股骨软骨和半月板的应力值，因此右前方向落地动作更容易增加下关节内部组织的损伤风险。

Objective:

Stepping as the basic step in badminton is one of the common actions that cause knee joint injuries. A large number of studies have shown that the direction of stepping is an important factor in causing knee joint injury, but there is little research on the internal structural stress characteristics of the knee joint under different stepping directions, and the specific mechanism of knee joint injury caused by stepping direction is not yet clear. Therefore, this study adopts biomechanical methods and finite element analysis methods to analyze the knee joint under different directions of stepping movements, aiming to explore the biomechanical characteristics of the knee joint under different directions of stepping and the impact damage mechanism of the internal structure. In order to provide certain theoretical support for preventing knee joint injuries in badminton sports and provide theoretical guidance for daily badminton training.

Methods:

This study recruited 15 male badminton majors from the School of Physical Education and Sports of Beijing Normal University to participate in sports tests. The Vicon infrared motion capture system is used to collect kinematics data, and a Kistler force table is used to synchronously collect dynamics data. Import the results into Visual 3D software for analysis.

In the study, a healthy subject was selected for CT and MRI scanning of the right knee joint in the supine state without weight bearing. The results were imported into Mimics19.0 for segmentation and smoothing to obtain a geometric modeling. Geomagic 2014 was used for smoothing and reverse processing to establish a solid model. Hypermesh 14.0 was used for pre-processing, including mesh division of each structure, and the results were imported into Abaqus2020 for post-processing, including material attribute setting. Compare the contact area and peak contact stress of the tibial joint with previous research results to verify the effectiveness of this model. Analyze the stress-strain characteristics of the internal tissues of the knee joint through loading loads.

Research results:

1. kinematics data results:

Knee joint angle at the peak moment of internal reaction force during the second action:The knee joint flexion angle of the left forward step is -64.22 ± 10.08 °, and the knee joint flexion angle of the right forward step is -69.67 ± 13.60 °. There is no statistical difference between the two tasks (P=0.275). The knee joint varus angle of the left front step is -4.12 ± 3.22 °, while the knee joint varus angle of the right front step is -21.3.1 ± 4.77 °. There is a statistical difference between the two tasks (P<0.05). The knee joint external rotation angle of the left front step is 15.64 ± 7.08 °, and the knee joint internal rotation angle of the right front step is -27.21 ± 7.55 °. There is a statistical difference between the two tasks (P<0.05).

2. Dynamics data results:

(1) Knee joint reaction force at the peak moment of internal reaction force during the second action:The horizontal reaction force of the knee joint in the left forward step is -1.66 ± 2.42 N/Kg, and the horizontal reaction force of the knee joint in the right forward step is -4.27 ± 3.24 N/Kg. There is a statistical difference between the two tasks (P<0.05). The knee joint shear force of the left front step is 9.22 ± 6.68 N/Kg, while the knee joint shear force of the right front step is 9.64 ± 5.97 N/Kg. There is no statistical difference between the two tasks (P=0.688). At the peak moment of ground reaction force, the vertical reaction force of the knee joint in the left forward step is 2.77 ± 7.13 N/Kg, and the vertical reaction force of the knee joint in the right forward step is 2.61 ± 5.26 N/Kg. There is no statistical difference between the two tasks (P=0.325).

(2) Knee joint torque at peak moment of reaction force during the second action phase:

The knee joint flexion torque of the left front step is -2.43 ± 0.78 N * M, and the knee joint extension torque of the right front step is 0.35 ± 0.50 N * M. There is a statistical difference between the two tasks (P<0.05). At the peak moment of ground reaction force, the knee joint inversion torque of the left front step is -0.20 ± 0.16 N * M, and the knee joint inversion torque of the right front step is -0.5 ± 0.25 N * M. There is a statistical difference between the two tasks (P<0.05). At the peak moment of ground reaction force, the knee joint external rotation torque of the left front step is 0.15 ± 0.19 N * M, and the knee joint internal rotation torque of the right front step is -0.73 ± 0.31 N * M. There is a statistical difference between the two tasks (P<0.05).

3. Finite element analysis results:

The stress and contact stress results of the patellar cartilage, lateral tibial cartilage, femoral cartilage, and meniscus during the second phase of the left front direction step at the peak ground reaction force are 1.86 MPa and 2.20 MPa, respectively; 6.09MPa, 2.48 MPa; 1.29MPa, 5.80 MPa; 3.52MPa, 5.45MPa. The stress results of the patellar cartilage, lateral tibial cartilage, femoral cartilage, and meniscus in the second phase of the right front step at the peak ground reaction force are 9.13 MPa and 3.815 MPa, respectively; 6.09MPa, 2.97 MPa; 1.47MPa, 7.37 MPa; 4.17MPa, 6.85 MPa.

Research conclusion:

1. The knee joint of the right front direction step has a larger range of motion; The peak angle of knee joint inversion and pronation in the right front direction step is significantly greater than that in the left front direction step, but the peak angle of knee joint flexion is smaller than that in the left front step;

2. When stepping and hitting the ball, stepping in the right front direction will cause greater internal reaction force and bending, inversion, and internal rotation torque of the knee joint. Stepping in the right front direction may lead to a greater risk of knee joint injury.

3. According to the finite element model loading load, the stress values of the right front direction step are significantly higher than those of the left front direction step, lateral tibial cartilage, femoral cartilage, and meniscus. Therefore, the right front direction landing action is more likely to increase the risk of damage to the internal tissues of the lower joint.