Perceived social isolation (PSI) is a personal contextual factor that is associated with morbidity and mortality. It is a factor that contributes to a worse quality of life for individuals, being associated with a worse prognosis for several clinical conditions, including low back pain (LBP) and neck pain (NP). However, information on whether ISP is a possible risk factor for LBP and NP is scarce. The few studies that investigated social isolation in back pain have scope or methodological limitations.

To investigate the association between individual ISP and the presence of LBP and NP through a co-twin study.

Cross-sectional observational study of 141 pairs of complete twins. The sample was taken from the Brazilian Twin Registry. We used self-reported questionnaires to assess the occurrence of LBP and NP (yes or no) and the level of physical activity. The Friendship Scale was used to measure people's PSI. The Peas in a Pod and Pittsburgh Sleep Quality questionnaires were used to determine twin pair zygosity and sleep quality, respectively. Regression models were constructed to investigate whether people's ISP is associated with the occurrence of LBP or NP. Models were adjusted for potential confounders: family factors; age; gender; level of physical activity; and sleep quality.

The sample consisted of adults of good socioeconomic status, mostly female (73.76%). Most had LBP and/or NP (84.75%), social isolation (58.87%), poor sleep quality (62.42%) and did not practice regular physical activity (69.15%). A change of one point in 25 in people's perception of less social isolation represented a 6% reduction in the risk of having NP (OR:0.94; 95%CI:0.84–1.05) and an 8% reduction in risk to present LBP (OR :0.92; 95%CI:0.81–1.05), after adjusting models for possible confounding factors mentioned above, however the confidence intervals included 1.0, so the estimates did not reach significance statistic.

Our study is the first to investigate the association between these variables, adjusting for potential confounders, and the data suggest an association of PSI with NP and LBP, being a possible risk factor that can be taken into account in preventive approaches focused on individuals.

We consider that the results have a scientific, sociocultural, educational, and clinical practice impact, since the PSI is such an important personal contextual factor that is associated with several clinical conditions of health and quality of life, but which is still subjugated in the literature. We emphasize the importance of further studies to clarify gaps about PSI, particularly post-pandemic as our data were collected before the COVID-19 pandemic, and we believe that PSI risks due to COVID-19 may have increased. We hope that based on these results, health professionals will start to include the ISP in their assessment routine and, thus, more fully address the biopsychosocial model focused on the individual.