Mechanisms of injury in the cervical spine

The tolerance of the spine to fracture and ligamentous injury can be expressed in terms of the displacements and loads that are present at the onset of injury. For both normal physiological motions of the spine and abnormal conditions leading to injury, combinations of loads and displacements are present. It is hypothesized that combinations of extreme loads and displacements can produce specific spinal injuries. Investigations of cervical motion segments have revealed differences between the middle and lower cervical motion segments. However, external mechanical conditions do not always reflect the conditions and patterns of injury at the individual cervical vertebra. New methodologies provide the opportunity to better quantify the biomechanics of spine trauma and can suggest techniques for assessing the risk of injury