There are 24 vertebral bones in the human spine - 26 bony parts of the spine if you include the sacrum and coccyx at its base. Though these bones are separate elements from one another, they work together as one unit so that we may move our body in any direction, and while preventing against excessive movements that would strain the spinal nerves. Relative to one another, each of the main elements of the spine have an ideal position in order to absorb shock as the spine takes on weight, and so that the soft tissues that connect them are not stretched or strained. If a vertebral misalignment occurs, then soft tissue structures such as the discs, spinal ligaments, and facet joints may stretched or pulled in opposite directions from two points of attachment. These types of abnormalities may cause back pain, and may accelerate the rate of degeneration of some of the elements of the spine.
A serious vertebral misalignment may be referred to as a dislocation, Retrolisthesis, or Anterolisthesis. Retrolisthesis is the backwards displacement of a vertebra from its ideal position. Anterolisthesis is the forwards displacement of the vertebra out of position. A vertebral subluxation is a more subtle form of vertebral misalignment that will be less likely to show up on X-Rays, CT Scans, and MRIs. Nevertheless, spine specialists such as doctors of osteopathic medicine and chiropractors are trained to recognize these subtle changes in the spine, and how to ease the misaligned elements back into position. Vertebral subluxations may happen because of one of several reasons. They could happen because of arthritic changes to the spine that cause two vertebral elements to lock together, rather than moving or sliding against each other. Spine subluxations may occur because of the laxity of spinal ligaments that allow the bones they attach to move out of position, rather than being held in place. Subluxations may occur because of muscular deconditioning, which causes one or more vertebral bones to be pulled in the direction of the stronger muscle groups, on one side of the spine.
When one of these factors causes the bones to lose their normal motion or position, the spinal nerves may be affected as well as the soft tissues, muscles, and intervertebral discs. Doctors refer to this back condition as the Vertebral Subluxation Complex.
The vertebral Subluxation Complex may affect the musculoskeletal system, nervous system, and our body organs in one of two ways:
Spinal Kinesiopathology: Flexion, extension, and rotation of the spine is possible because each motion segment of it allows for movement. Movement of the spine is possible because of the motility of its individual motion segments. The motion segment of the spine consists of two adjacent vertebra, the disc between them, and the ligaments that hold them together. Several factors may result in one or more of these motion segments becoming locked, or stiff. This reduction in movement of one part of the spine may cause other parts of the spine to compensate as their joints move too much. This may cause injury to other spinal elements or distort the normal spinal curves.
Neuropathophysiology (abnormal nervous system function): The spine is the vehicle for the vulnerable spinal cord and its nerve roots to travel down the body. These nerve roots remain well protected when the vertebral bones and associated soft tissues are healthy. Structures may press against the nerves as they deteriorate, wear out, or become inflamed. When the nerves become compressed, the condition is called a pinched nerve or a compressive lesion. Compressive lesions which impact the nerves may result in numbness and loss of sensation in lower back pain conditions such as sciatica.