It is safe to say that low back pain is an epidemic that most of us will deal with at some point. In fact, 75-80% of the population in the experience low back pain at least once in their lifetime. At any given point in time, 30% of the united states population is experiencing low back pain. The total cost of low back pain in the united states is more then 50 billion dollars per year.

Of the many questions that patients have when they enter our office, a common one is what is causing this back pain that I have had for years? Before We can answer that question, we must review some basic spinal structure and function. The spinal column (or vertebral column) extends from the skull to the pelvis and is made up of 33 individual bones termed vertebrae. The vertebrae are stacked on top of each other group into four regions.

The Discs are avascular and therefore depend on the end plates to diffuse needed nutrients. The cartilaginous layers of the end plates anchor the discs in place. The intervertebral discs are fibrocartilaginous cushions serving as the spine’s shock absorbing system, which protect the vertebrae, brain, and other structures (i.e. nerves). The discs allow some vertebral motion: extension and flexion.

Nerves control the body’s functions including the vital organs, sensation, and movement. The nervous system receives information and initiates an appropriate response. It is affected by internal and external factors. Nerves follow tracts and cross over junctions called Synapses. Simplified, it is a complex communicative process between nerves conducted by chemical and/or electrical changes. Individual disc movement is very limited – however considerable motion is possible when several discs combine forces. The nerve roots pass out of the spinal canal through the intervertebral foramen, where they feed the body either anteriorly (motor) or posteriorly (sensory). The anterior divisions supply the front of the spine including the limbs. The posterior divisions are distributed to the muscles behind the spine.

The joints in the spine are called Facet Joints. Other names for these joints are Zygapophyseal or Apophyseal Joints. Each vertebra has two sets of facet joints. One pair faces upward and one downward. There is one joint on each side. Facet joints are hinge–like and link vertebrae together. They are located at the back of the spine.

Ligaments are fibrous bands or sheets of connective tissue linking two or more bones, cartilages, or structures together. One or more ligaments provide stability to a joint during rest and movement. Excessive movements such as hyper–extension or hyper–flexion, may be restricted by ligaments. Further, some ligaments prevent movement in certain directions.

Muscles are named according to their shape, location, or a combination. They are further categorized according function such as flexion, extension, or rotation. Muscles and ligaments work together to support the spine, hold it upright, and control movement during rest and activity.

Abnormal spinal biomechanics (movement), whether it be a decrease or increase movement, is a frequent cause of spinal pain. But what causes certain areas of the spine to experience a change in normal biomechanics? Abnormal spinal biomechanics is most commonly caused by degeneration, as in degenerative joint disease, and by injury to ligaments surrounding the spine (see picture above).

The areas of the spine- the discs, facets, ligaments and muscles-are loaded with specialized sensors that help dictate spinal posture and vertebral motion by sending signals to the brain about how much tension is required in the muscles surrounding the spine to keep the spine stable. Remember the brain controls everything in your body. As you can see, information from the specialized receptors are necessary to ensure adequate spinal stability. Unfortunately as we age, changes occur in our spine. The changes are primarily degenerative/arthritic and effect the bones and discs of the spine. As the spine degenerates, there is a significant amount of stress placed on the ligaments, discs, and facets of the spine. Degeneration however, is not the only cause of these changes.

In addition to spinal degeneration, a single episode of trauma (slip or fall) or repetitive micro trauma (bad posture over years/poor sleeping habits) . The trauma also adds puts stress to the ligaments, discs, and facets (see pictures of ligaments above). As we said before, ligaments are loaded with the special messangers that contribute to spinal stability. Now, with degeneration and/or trauma, there is an increase in stress on the ligaments, the receptors in the ligaments will also be stressed and will not send proper messages to the brain.

Since the brain is not receiving proper signals, it can not send proper signals to the muscles around the spine, and the spine can not be adequately stabilized. This leads us susceptible to pain and injury. Since the muscles around the spine are not working properly, this causes the bones of the spine to malfunction. Some may begin to move too much because there is not enough strength in the muscles or some bones may become stuck and misaligned because the muscles surrounding it iss too tight! Typically, a combination of both occurs.

In either case, the spine is stressed. Abnormal spinal stress and strain cause chronic inflammation of spinal tissue that we discussed, all of which are extremely sensitive to pain. Although the injured spinal ligaments and tissues will heal over time, the signals from thes receptors in the ligamenst can be disrupted permanently and spinal integrity can be compromised over a lifetime, hence, chronic pain, and/or poor posture.

Chiropractic helps to restore normal messages from the receptors of the spine, through chiropractic adjustments. Because chiropractic works to restore the signals in to the brain, with the hopes of improving signals out to the muscles (leading to a more stable spine) can be one reason why chiropractic spinal adjustments have proven to be more effective in treating chronic spinal pain when compared to medication, exercise, and needle acupuncture.