Effect of Neck Muscles Activity on Cervical Spine Injury during Motorcycle Collisions

• Main Authors: Yuan-Yi Fan, 范遠一
• Other Authors: Sai-Wei Yang
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/89525270829061776006

碩士 === 國立陽明大學 === 醫學工程研究所 === 95 === Motorcycle has been the most popular transportation in Taiwan, but traffic accidents relating to motorcycles have accounted for the majority of severe injuries or death among all transportation. Head injury in traffic accidents causes severe injury and death; however, cervical spine injury can cause paralysis and death of the patient. Severe injuries, such as cervical spinal cord injury, definitively deteriorate the quality of life of the patients. Cervical spine injuries are less studied in traffic accidents, especially for the motorcyclist. Previous studies focus primarily on criteria and tolerance at both ends of human cervical spine during axial-drop test and sled-test (whiplash syndrome), parameters are usually described in forces and moment. Neck muscles are usually neglected when injury analysis was studied. Detailed injury mechanisms and effect of neck muscles in cervical spine injury are not well understood. The purpose of this study is to develop a head-neck-torso model with neck muscles and using this model for injury analysis of cervical spine in motorcycle-car accidents. Finite element analysis is conducted for local stress and force in cervical spine model. LS-DYNA dynamic finite element software is used for crash impact simulation in this study. Developed model is validated with regard to 15G volunteer sled tests by Ewing et al (Ewing, 1976a) for kinematics and ROM. Boundary conditions include forces and moments applied at torso, and initial conditions include velocity and angular velocity applied at head, neck, and torso. Simulation conditions are selected for head impacts from result of ADAMS (Wu, 2003) and imported into LS-DYNA. Three types of crashes include rear-end, head on, and side crashes in the simulations. Results are analyzed in dynamic responses of stress and contact forces in cervical vertebral bodies and ligaments with and without neck muscles activation. Developed head-neck-torso model is successfully validated in kinematics and ROM. In injury analysis of cervical spine, it is found that activated neck muscles increases ligamentous injury in all crash simulations; bone injuries are found less frequently in anterior of the spinal functional unit, but injuries found more frequently in the posterior region. Bone fractures due to contact force are found reduced when neck muscles are activated. The 1st mode shape of cervical spine is found in all three types of simulations, and curvatures of cervical spine in multi-plane are found in head-on crash. Fracture of dens and atlas are primary injury types in all crash simulations, and potential of spinal cord injury becomes higher with the prolapse of intervertebral discs.