Structures Injured in Whiplash Generate Pain and Loss of Function
Traumatic events that cause injury to the structures in the spine can generate painful stimuli that may produce irreversible functional losses. This educational flier is focused on dispelling myths related to the innervations of the intervertebral disc and surrounding structures of the spinal column.It is important to understand that research related to the innervations of the intervertebral disc and the front of the spinal canal has been going on since the early 1930s. With that being said, the nerve supply to these structures was well defined by the 1960s.
The facts of how these areas are “wired” have been established for the past 49 years. THESE NERVES ARE DIFFERENT THAN THE SPINAL NERVE ROOTS.
In a recent research review published in 2007 by M. A. Edgar, the author states, “Branches were traced to the posterior longitudinal ligament, to the outer layers of the annulus fibrosus, and to the anterior dura” (p. 1135).The most interesting fact about the research surrounding the innervation of the intervertebral disc is contained in the following statement by the author, “Most authors concluded that the lumbar sinuvertebral nerves had up to three segmental levels of overlap…” (Edgar, 2007, p. 1135). This shows that there is a redundancy of innervation and demonstrates how injuries to one spinal level can have effects on adjacent levels.
The following structures contain nerve endings that transmit pain:
- Intervertebral Disc
- Healthy Disc – outer 1/3 of the annulus fibrosis
- Degenerated Disc – increased innervation as far inward as the nucleus pulposus
- Posterior Longitudinal Ligament
- Anterior Dural Sac
- This is important in cases where the disc herniation is compressing the sac that surrounds the nerve roots and spinal cord.
- Outer Layer of the Vertebral Body
Understanding anatomical structures and how they relate to bodily injury and persistent functional loss are extremely important to the diagnosis, management and documentation of the traumatically injured.