Washington, Apr 9 : A twin study has shown that physical strain and exertion are not the only causative factors behind back pain, by finding that an individual's genetic makeup also plays an important role in the development of the condition.
The researchers found that back pain problems have more to do with genetics than physical exertion.
The Twin Spine Study, started in 1991 is an ongoing research program and with the above finding, it has completely upturned the understanding of disc degeneration. A paper on the study, detailing the root causes of disc degeneration received a Kappa Delta Award from the American Academy of Orthopaedic Surgeons.
"In the past, the factors most commonly suspected of accelerating degenerative changes in the discs were various occupational physical loading conditions, such as handling of heavy materials, postural loading and vehicular vibration," said lead researcher Michele Crites-Battie of the University of Alberta's Faculty of Rehabilitation Medicine.
The study was based on information from 600 participants in the population-based Finnish Twin Cohort-147 pairs of identical and 153 pairs of fraternal male twins and involved the comparison of identical twin siblings who differed greatly in their exposure to a suspected risk factor for back problems. For example, one of the twins had a sedentary job while the other had heavy occupational physical demands, or one routinely engaged in occupational driving while the other did not.
The study came up with astonishing results, and indicated that genetics play a much larger role in disc degeneration than previously thought. In fact, despite extraordinary differences between identical twin siblings in occupational and leisure-time physical loading conditions throughout adulthood, only a little effect on disc degeneration was observed.
The results of the study indicated that while physical loading, handling heavy loads, bending, twisting and static work in awkward postures, appears to influence disc degeneration, its effects are not very significant.
Crites-Battie said that during the course of the exposure-discordant twin studies, there was a strong resemblance in disc degeneration in identical twins, not only in the degree of degeneration, but also in the types of findings and spinal levels involved.
"This advance in the understanding of disc degeneration provides a foundation from which to develop new hypotheses and more fruitful research that may help shed light on one of the most common and costly musculoskeletal conditions facing the developed countries of the world," said Crites-Battie.