Car accident whiplash settlement cases involve a sudden extension of the cervical spine (backward movement of the neck) and flexion (forward movement of the neck). This type of trauma is also referred to as a cervical acceleration-deceleration (CAD) injury. Rear-end or side-impact motor vehicle collisions are the number one cause of whiplash with injury to the muscles, ligaments, tendons, joints, and discs of the cervical spine.