The Four Phases of a Whiplash Injury
During a rear-end automobile collision, your body goes through an extremely rapid and intense acceleration and deceleration. In fact, all four phases of a whiplash injury occur in less than one-half of a second! At each phase, there is a different force acting on the body that contributes to the injury as a whole, and with such a sudden and forceful movement, damage to the vertebrae, nerves, discs, muscles, and ligaments of your neck and spine can be substantial.
During this first phase, your car begins to be pushed out from under you, causing your mid-back to be flattened against the back of your seat. This results in an upward force in your cervical spine, compressing your discs and joints. As your seat back begins to accelerate your torso forward, your head moves backward, creating a shearing force in your neck. If your head restraint is properly adjusted, the distance your head travels backward is limited. However, most of the damage to the spine will occur before your head reaches your head restraint. Studies have shown that head restraints only reduce the risk of injury by 11-20%.
During phase two, your torso has reached peak acceleration – 1.5 to 2 times that of your vehicle itself – but your head has not yet begun to accelerate forward and continues to move rearward. An abnormal S-curve develops in your cervical spine as your seat back recoils forward, much like a springboard, adding to the forward acceleration of the torso. Unfortunately, this forward seat back recoil occurs while your head is still moving backward, resulting in a shearing force in the neck that is one of the more damaging aspects of a whiplash injury. Many of the bone, joint, nerve, disc and TMJ injuries that I see clinically occur during this phase.
During the third phase, your torso is now descending back down in your seat and your head and neck are at their peak forward acceleration. At the same time, your car is slowing down. If you released the pressure on your brake pedal during the first phases of the collision, it will likely be reapplied during this phase. Reapplication of the brake causes your car to slow down even quicker and increases the severity of the flexion injury of your neck. As you move forward in your seat, any slack in your seat belt and shoulder harness is taken up.
This is probably the most damaging phase of the whiplash phenomenon. In this fourth phase, your torso is stopped by your seat belt and shoulder restraint and your head is free to move forward unimpeded. This results in a violent forward-bending motion of your neck, straining the muscles and ligaments, tearing fibers in the spinal discs, and forcing vertebrae out of their normal position. Your spinal cord and nerve roots get stretched and irritated, and your brain can strike the inside of your skull causing a mild to moderate brain injury. If you are not properly restrained by your seat harness, you may suffer a concussion, or more severe brain injury, from striking the steering wheel or windshield.
Injuries Resulting from Whiplash Trauma
Whiplash injuries can manifest in a wide variety of ways, including neck pain, headaches, fatigue, upper back and shoulder pain, cognitive changes and low back pain. Due to the fact that so many factors play into the overall whiplash trauma, such as direction of impact, speed of the vehicles involved, as well as sex, age and physical condition, it is impossible to predict the pattern of symptoms that each person will suffer. Also, whiplash symptoms commonly have a delayed onset, often taking weeks or months to show up. Click here to read more about Why Chiropractic Care After Whiplash Injuries.
It is the single most common complaint in whiplash trauma, being reported by over 90% of patients. Often this pain radiates across the shoulders, up into the head, and down between the shoulder blades. Whiplash injuries tend to affect all of the tissues in the neck, including the facet joints and discs between the vertebrae, as well as all of the muscles, ligaments and nerves. – Learn more about Neck Pain here.
After neck pain, headaches are the most prevalent complaint among those suffering from whiplash injury, affecting more than 80% of all people. While some headaches are the result of direct brain injury, most are related to injury of the muscles, ligaments and facet joints of the cervical spine, which refer pain to the head. – Learn more about Headaches here.
A less common, but very debilitating disorder that results from whiplash is temporomandibular joint dysfunction (TMJ). TMJ usually begins as pain, clicking and popping noises in the jaw during movement. If not properly evaluated and treated, TMJ problems can continue to worsen and lead to headaches, facial pain, ear pain and difficulty eating. – Learn more about TMJ Problems
Believe it or not, mild to moderate brain injury is common following a whiplash injury, due to the forces on the brain during the four phases mentioned earlier. The human brain is a very soft structure, suspended in a watery fluid called cerebrospinal fluid. When the brain is forced forward and backward in the skull, the brain bounces off the inside of the skull, leading to bruising or bleeding in the brain itself. – Learn more about Brain Injuries here.
Dizziness following a whiplash injury usually results from injury to the facet joints of the cervical spine, although in some cases injury to the brain or brain stem may be a factor as well. Typically, this dizziness is very temporary improves significantly with chiropractic treatment. – Learn more about Dizziness here.
Although most people consider whiplash to be an injury of the neck, the low back is also commonly injured as well. In fact, low back pain is found in more than half of rear impact-collisions in which injury was reported, and almost three-quarters of all side-impact crashes – Learn more about Low Back Pain here.