自行车种类及骑行姿态对骑车人下肢损伤机理的影响

Influence of Bicycle Patterns and Riding Postures on Injury Mechanism of Cyclist Lower Extremity

为了研究汽车-自行车碰撞过程中,自行车种类及骑行姿态对骑车人下肢运动学及损伤的影响,建立共享自行车和山地自行车有限元模型,采用脚前部、脚上部和脚下部3种骑行姿态,选取碰撞速度为40 km/h,骑行速度为10 km/h,构建6种碰撞工况来考察骑车人下肢运动学响应和损伤状况的差异性.结果表明,相比于共享自行车,带有高横杠车架结构的山地自行车使得骑车人的被撞侧腿部承受更大的弯矩,且该结构限制了骑车人下肢的移动,从而影响膝关节的运动学响应和韧带损伤.在脚下部的骑行姿态下,骑车人承受下肢严重损伤的概率要更大,胫骨承受较大弯矩为257.5 N·m,内侧副韧带出现最大拉伸长量为19.3 mm.因此,自行车种类对骑车人下肢运动学响应产生较大影响,骑行姿态对下肢损伤产生较大影响.

This study aims to identify the influence of bicycle types and riding postures on the lower extremity kinematics and injury of cyclists during vehicle-bicycle collisions.For this purpose,the finite element models of two typical bicycles(shared bicycle and mountain bike)were established.Three types of riding postures(Struck foot front,up,and down)and a collision speed of 40 km/h as well as a riding speed of 10 km/h were adopted to conduct the current study.At last,the kinematic response and injury condition were analyzed through a matrix of 6 simulation tests using different bicycle types and riding postures.The results showed that compared with the shared bicycle,the bicyclist riding the mountain bike with a high cross-bar frame structure suffered a high tibia fracture risk.The high cross-bar frame structure of the mountain bike limited the movement of the lower leg during the collision.The kinematic response of the knee joint and ligament injury was affected as a result.The current study also determined that bicyclists with struck foot down riding posture were prone to sustain severe lower extremity injuries.In this position,the tibia is subjected to a large bending moment of 257.5 N·m.The medial collateral ligament has an elongation value of 19.3 mm.Therefore,the kinematic response of the cyclist’s lower leg extremity varies with the types of bicycle,whereas the lower extremity injuries change with the riding postures.