Clinical and Biomechanical Analyses of Whiplash Injuries

An extensive series of biomechanics studies, including clinical aspects and facet capsule ligament mechanics as well as injury mechanisms, was undertaken to help gain a better understanding of whiplash injury and cervical facet pain. These studies provide the following evidence: (1) Whiplash injuries are generally considered to be a soft tissue injury of the neck with symptoms such as neck pain and stiffness, shoulder weakness, dizziness, headache and memory loss. (2) Experimental findings have examined strains across the facet joint as a mechanism of whiplash injury, and suggested a capsular strain threshold or a vertebral distraction threshold for whiplash related injury, potentially producing neck pain. (3) Injuries to the facet capsule region of the neck are a major source of post-crash pain. (4) There are several hypotheses of how whiplash associated injury may occur and three of these are related strains within the facet capsule connected with events early in the impact. These results form the biomechanical basis for a hypothesis that the facet joint capsule is a source of neck pain and that the pain may arise from large strains in the joint capsule that cause pain receptors to fire.