Referred Back Pain
Referred pain is pain that is felt or experienced in one location of the body, as a result of a true source of pain in another location. A common example of this condition is referred back pain. Two common examples of referred back pain are muscle spasms and sciatica that occur due to ligament or nerve damage in the soft tissues of the spine. Benjamin E. Benjamin, an accomplished researcher in the study and treatment of referred pain patterns, proposed three general guidelines, or principles, for finding the ultimate source of referred pain.
- Pain refers away from the core of the body, out toward the extremities.
- Referred pain does not cross the midline of the body. (An injury on the right side does not refer pain to the left side. (An exception to this rule could include disc disease where the both nerve roots at that level of the spine are affected.)
- The distance of the referred pain from the point of injury reflects the severity of the injury.
Many injuries and diseases that affect the soft tissues of the spine have the effect of causing pain near the area of the injury, as well as to all the structures and organs that are supplied with information by the nerves affected by these injuries. At each level of the spine, a pair of nerve roots exits from each side of the vertebral column. Each nerve root that exits the human spine through these openings is known as a nerve root. Near the point of exit, the nerve root branches four more times. Three of these branches travel to the nearby muscles in that area of the spine, as well as the soft tissues involved in movement and protection of the spine. The fourth nerve branch travels to a more distant location to supply information to an organ or body part. If the nerve were to become compromised, due to arthritic changes to the soft tissues of the spine, or a loosening of the spinal ligaments, structures linked to that nerve may become painful or disabled. This condition would include the majority of cases of referred back pain.
Careful research and mapping of the nerves of spine and peripheral nervous system (which includes all the nerves outside of the brain and spine) has enabled us to know which nerve roots supply each area of the body. For example, we know that the nerve roots that exit the spine at the level of C5, C6, C7, and T1 are involved in the feeling conscious motor abilities in our arms, wrist and hand. We also know that the nerve roots at the level of L1-L5 and L5-S1 are involved in our ability to feel and move our arms and legs. This understanding of the mapping and charting of the nervous system is not 100% precise, because there seems to be an overlap of functions from the nerve roots at certain levels of the spine. For example, we know that the nerves at the levels of L4-L5 and L5-S1 are involved in thigh abduction. This understanding into the routes that the main nerves of the body has enabled us to find the source of referred pain in the majority of cases.