Accident data show that lower limb is one of the most frequently injured body parts for cyclists in vehicle collisions. However, studies of cyclist lower limb injuries and protection are still sparse. Therefore, the purpose of this study is to investigate the kinematics and injury mechanism of cyclist lower limb in vehicle-to-bicycle collisions considering different impact boundary conditions. To achieve this, the finite element (FE) modeling approach and an FE human body lower limb model with detailed muscles were employed, and impact boundary conditions with different vehicle front-end shapes and cycling postures were considered. Predictions of lower limb kinematics, knee ligament elongation and bending moment of upper and lower leg were used for analysis. The simulation results show that cycling posture has a significant influence on cyclist lower limb kinematics and injury risk, lateral bending toward the direction of vehicle or vehicle moving combining with lateral shearing is the main mechanism for cyclist knee ligament injuries, and injuries to long bones of cyclist leg in vehicle impacts could form lateral bending at both directions. The findings suggest that the influence of cycling posture and distinct difference in injury mechanism between cyclist and pedestrian should be considered in the assessment of vehicle safety design for cyclist lower limb protection.

中文翻译：

---

车辆与自行车碰撞中骑车人下肢的运动学和损伤机制

事故数据显示，下肢是车辆碰撞中骑行者最容易受伤的身体部位之一。然而，关于骑自行车者下肢损伤和保护的研究仍然很少。因此，本研究的目的是研究考虑不同碰撞边界条件的车辆与自行车碰撞中骑车人下肢的运动学和损伤机制。为此，采用有限元 (FE) 建模方法和具有详细肌肉的 FE 人体下肢模型，并考虑了不同车辆前端形状和骑行姿势的冲击边界条件。对下肢运动学、膝关节韧带伸长和上下腿弯矩的预测进行分析。仿真结果表明，骑行姿势对骑行者下肢运动学和受伤风险有显着影响，向车辆或车辆行驶方向横向弯曲并结合横向剪切是骑行者膝关节韧带损伤的主要机制，长骨损伤车辆撞击时骑车人的腿可能会在两个方向上形成横向弯曲。研究结果表明，在评估骑车人下肢保护的车辆安全设计时，应考虑骑车姿势的影响以及骑车人与行人之间伤害机制的明显差异。在车辆撞击中骑车人腿的长骨受伤可能会在两个方向形成横向弯曲。研究结果表明，在评估骑车人下肢保护的车辆安全设计时，应考虑骑车姿势的影响以及骑车人与行人之间伤害机制的明显差异。在车辆撞击中骑车人腿的长骨受伤可能会在两个方向形成横向弯曲。研究结果表明，在评估骑车人下肢保护的车辆安全设计时，应考虑骑车姿势的影响以及骑车人与行人之间伤害机制的明显差异。