Whiplash Affects Cervical Spine Biomechanics

Whiplash injuries affect millions of people around the world each year. These injuries are most commonly the result of low velocity automotive rear impacts. While an extraordinary body of literature exists documenting clinical, epidemiological, and experimental studies, the exact cause and location of the injury and factors affecting the severity remain enigmatic. Clinical and experimental literature repeatedly highlighted influencing factors to include gender, impact severity, spinal degeneration (abnormal curvature), and occupant awareness of the impending collision. The present research quantified the effects of these issues on the biomechanics of the cervical spine using experimental and computational models. The experimental intact head-neck complex model was used to determine gender differences in cervical spine kinematics, and the head-neck computational model was used to investigate ligament elongations as a function of spinal level, impact severity, occupant awareness, and spinal degeneration. Chapter 1 introduces the whiplash topic through a description of epidemiology, including incidence and societal costs, and various theories of the whiplash injury mechanism. Chapter 2 gives a brief outline of the anatomy of the cervical spine, the likely region(s) affected by whiplash injury, and provides a background of the literature on the factors listed above. Chapter 3 describes the experimental investigation of the effects of gender, impact severity, and spinal level using the intact head-neck cadaver model. Chapters 4 through 7 describe the computational model. In particular, Chapter 4 describes the head-neck model and validation using experimental results from this research (Chapter 3) and other literature findings. Chapter 5 discusses effects of spinal level and impact severity. Chapters 6 and 7 describe the effects of occupant awareness in the form of cervical muscle contraction and spinal degeneration in the form of abnormal spinal curvatures. Conclusions are presented in Chapter 8