Laziness Or Heredity – What Makes The Back Hurt?

Researchers have used twins to investigate the influence of movement behavior on the development of permanent back pain — with astonishing results.

Sooner or later, almost everybody gets it. Back pain is and will remain a national disease, in Germany and elsewhere. The Bertelsmann Stiftung, Gütersloh, Germany has established in a study that one out of five covered by a public health insurance consults a doctor at least once a year for back pain, and 27 percent of them even visit a doctor four times or more. The good news is that most back pain is not caused by serious diseases such as tumors or destroyed vertebral bodies or discs and will be a thing of the past after a few weeks at the latest. In some people, however, the pain remains, although the cause has long since disappeared, the tension is relieved, and the nerve has recovered.

Sitting and inactivity are considered a risk factor for the development of back pain. However, researchers from Australia and Spain believe that its influence may have been overestimated so far. Studies have repeatedly found a connection between inactivity and back pain. In 2008, for example, researcher Björck-von Dijken from Sweden showed in a study of 5798 people (1) that back pain was more common among those who were less active in their free time. On the other hand, sitting at work seems to have less influence than many people think. The Robert Koch Institute, Berlin, for example, writes, “Contrary to a widespread prejudice, a predominantly sedentary job does not seem to present a significant risk of back pain.” This is also underlined in a critical literature review  (2)

The researchers around Anita Amorim from the University of Sydney, New South Wales, Australia have now selected twins for their study (3). The advantage of twin studies is that they can also be used to find out the influence of genes and very early experiences on a trait such as back pain. Studies have shown that the heredity of lower back pain could exceed 60 percent. If one wants to understand how important daily activity is for the development of back pain, one must be able to exclude the influence of genes.

Between 2009 and 2013, the researchers interviewed more than 2000 identical and fraternal twins several times. A total of 38 percent of the twins reported having suffered from persistent back pain once in their lives. In addition, 58 percent said they did not move much. In 22 percent of the twins, permanent pain did not occur until the course of the study. When the researchers then compared the data of the different twins, they found that an inactive lifestyle was only associated with back pain in women, not in men. However, although women who did not move much reported lower back pain more frequently, the link was not as obvious when the researchers calculated the influence of genes and early experiences. Therefore, the scientists suspect that these factors have a significant influence on the relationship between movement and back pain. It also seems to depend on the genes how one’s own movement behavior affects the development of back pain.

However, the researchers admonish that their results should be read with care, since larger studies would have to confirm the results. Nevertheless, it is possible that too little attention has been paid to the influence of genes in the relationship between physical activity and back pain.

This is part 23 of a series covering twin health provided by Paul Enck from the Tübingen University Hospital and science writer Nicole Simon. Further studies in twin research can be found at TwinHealth website. Translation was done with the assistance of DeepL translator.

References:

1. Björck-van Dijken C1, Fjellman-Wiklund A, Hildingsson C. Low back pain, lifestyle factors and physical activity:  a population based-study. J Rehabil Med. 2008;40(10):864-9.
2. Hartvigsen J, Leboeuf-Yde C, Lings S et al. Is sitting-while-at-work associated with low back pain?  A systematic, critical literature review. Scand J Public Health 2000; 28 (3): 230–9
3. Amorim AB1, Levy GM2, Pérez-Riquelme F3 et al.  Does sedentary behavior increase the risk of low back pain?  A population-based co-twin study of Spanish twins. Spine J. 2017;17 (7):933-42