Twin study finds that back pain, neck-shoulder pain may be partly genetic

Oct 13 2011
Research involving almost 7,000 pairs of twins suggests that low back pain as well as neck-shoulder pain may at least be partly genetic, as published in the Oct. 15 issue of Spine.

About 80 percent of Americans will have back pain at some point in their lives. It is the most common neurological disorder, second only to headaches, and is a leading cause of disability and lost wages from time taken off work, according to the Centers for Disease Control and Prevention.

Back pain can be the result of injury, disease or age-related degeneration to any of the structures that protect the spinal cord: the vertebrae, the facet joints connecting the bones or the intervertebral discs that stabilize movement of the spine. Several conditions can cause parts of the spine to put pressure on the surrounding nerves, leading to back pain that can radiate out to other parts of the body.

Spinal stenosis occurs when the column narrows on the spinal cord because of thickening ligaments or bone spurs that grow as a response to osteoarthritis. Degenerative disc disease can cause the shock-absorbing cushions between the vertebrae to bulge out, rupture or become thinner, making movement more painful. The facet joints that connect the vertebrae may also age and cause the bones to slip and slide out of place, leading to conditions such as spondylolisthesis. The muscles and ligaments in the back may also be prone to strain injuries from overactivity.

Several factors can increase one's risk for back pain, including excess body fat that puts extra mechanical demands on the back, or smoking, which can interfere with the flow of nutrients into parts of the spine. There is also a growing body of research suggesting that some types of pain are partly genetic.

Scientists conducted a survey assessing back pain in subjects taken from the Swedish Twin Registry, a resource to help study the role of genetics in health. More than 7,000 pairs of twins, including identical siblings and fraternal siblings that were of the same sex or opposite sex, answered questionnaires measuring their experiences with lower back pain, neck-shoulder pain or concurrent cases of both conditions.

The results showed that genetics play a strong role in the development of concurrent lower back pain and neck-shoulder pain. Though genetics may also influence cases of pain that strike only the lower back or only the neck-shoulder region, the effect is not as strong, according to the researchers.