REPRODUCING BIOMECHANICAL CERVICAL PHENOMENA IN LOW-SPEED REAR-END COLLISIONS BY K-D NECK MODEL

摘要

Although there have been many attempts to clarify the mechanism of whiplash injuries recently, the mechanism is still not fully understood. This is because it is difficult to reproduce actual rear-end automobile accidents in research test. To solve this problem, we conducted experimental and numerical analyses. First, we developed a new biomechanical cervical model named the "K-D neck model" to reproduce human neck movements in low-speed rear-end collisions. Shear displacements were observed in the plane of the intervertebral disks. Secondly, to verify the biomechanical fidelity of the K-D neck model, numerical analyses using finite element models with both active and passive muscle elements were conducted to compare each lateral head displacement of a cadaver, a volunteer and the K-D neck model. To reduce whiplash injuries, a car seat equipped with a new headrestraint system was developed. The headrestraint swings forward during low-speed rear-end collisions. Through sled tests, we measured the neck's lateral and longitudinal cervical movements every 1 millisecond (msec), and observed that the faster support of the dummy head was effective in reducing both lateral and longitudinal displacements between each cervical vertebra.