Whiplash associated disorders (WADs) can be a very confusing condition characterized by a myriad of symptoms stemming from a forceful, rapid back-and-forth motion of the head and neck. While this process commonly occurs during a rear-end crash, it can also arise from a slip-and-fall injury, sports injury, physical abuse, or any type of trauma involving a quick, forceful impact. To understand how this happens, let’s discuss the mechanism of injury and how fast the head and neck movements are that occur in a classic rear-end collision.
One paper that utilized kinematic studies on cadavers and healthy volunteers reported that a WAD injury can occur in any one of three stages during the impact. STAGE 1: Flexion or forward movement of the head/neck starts with a flattening of the normal C-shaped curve. STAGE 2: The curve then reverses into an S-shaped curve with the lower half of the cervical spine (or neck) extending (C-shaped) and upper half flexing (reverse C-shape) forming the S-shaped spinal curve prior to the head/neck fully flexing. STAGE 3: The entire cervical spine extends into an extreme of the normal C-shaped curve as the head rebounds backward, hopefully stopped by a properly fitting headrest!
These three stages occur FAST—in about 600 milliseconds, which is MUCH quicker than someone can voluntarily contract a muscle. Hence, it’s next to impossible to “brace” for the impact because it’s over before we can react!
Anatomically, the front of the cervical spine is made up of large square-shaped bones called vertebral bodies (VBs) of which there are seven in the neck, each separated by a shock-absorbing disk. There is a strong ligament that runs the entire length of the spine in the front and back of the VBs that help stabilize the spine, or vertebral column. There’s another ligament in the back part of the vertebral canal where the spinal cord travels from the brain to the low back and two “facet joints” at each of the seven vertebrae that holds them together. Hence, each level is like a tripod with a big supporting leg in the front (the VBs) and two spatulated legs in the back (the facets) that allow for motion and protect the cord and exiting nerve roots, which allows us to feel textures and temperatures, as well as move our limbs.
When the head whips forward (Stages 1 & 2), the front of the cervical spine jams together while the facets in the back spread open. This is where the VBs in front can compression fracture and/or the capsules surrounding the facet joints in the back can over-stretch and tear. The latter has been reported to be a common and major source of post-crash pain in WAD injuries.
While many individuals will heal without significant issues after a whiplash injury, up to 50% will continue to experience symptoms such as neck and upper back pain, stiffness, loss of mobility, dizziness, blurred vision, headache, memory loss, and other cognitive dysfunctions associated with concussion. This underscores the importance of seeking prompt treatment (chiropractic care offers a great choice) to reduce the risk of WAD transitioning into a chronic, long-term, and life affecting condition.