Neck Injury Analysis Of A 6-year-old Child Occupant During Vehicle Rear Impact Using Finite Element Method

In the vehicle rear impact,the whiplash injury is the most frequent occurrence of the cervical spine injury.Although the whiplash injury is not fatal,it causes long-term pain to the patient.In the past studies,many efforts have been made to understand the biomechanics of adult cervical spine,but the study on the mechanism of the cervical spine injury in children is very limited.Although children have safe seat protection when they ride in the car,there will be too much acceleration at the moment of vehicle collision.Because of the height,proportion and the not fully developed soft tissue of the children,the children are prone to damage in the car collision.Based on the validated finite element model of the 6-year-old pediatric neck,the ligaments were simulated with two kinds of element types of membrane element and spring element respectively,and the simulation experiments were carried out by the cadaver experiment respectively.At the same time,the membrane element model was used to simulate the bending test.The effects of membrane element and spring element on the biomechanical response of the neck ligaments were compared and analyzed.The results show that the simulation results of the membrane element simulation are good comparing to the cadaver experiment,and the results of the spring element simulation are quite different from those of the cadaver experiment,and the simulation results of the membrane element bending test are good.This shows that the spring element has some limitations in the force simulation and the membrane element has higher biofidelity and can reflect the biomechanical response of the ligaments.Using the existing 6-year-old pediatric head and neck finite element model,after applying five groups of the linear acceleration to simulate the post-collision,and based on the whiplash injury,the response of the linear acceleration to the pediatric neck injury in the post-collision was analyzed from various aspects.Based on the validated neck finite element model of the 6-year-old child,the pediatric cervical spine flexion test,extension test,and lateral bending test were performed by applying five different groups of moment loads,and the injury response of the pediatric cervical spine during bending was analyzed.Based on the validated 6-year-old pediatric head finite element model and the 6-year-old pediatric neck finite element model,the head-neck connection was performed,and the 6-year-old child occupant whole finite element model was perfected.The model is used to carry out the post-collision simulation test of the child,and the kinematic response of the head and neck of the 6-year-old child in the rear collision is analyzed,which provides a theoretical reference and basis for future research on the neck injury and protection.