Abstract
Low back pain (LBP) is one of the most prevalent musculoskeletal complaints and a leading cause of disability worldwide. Although patients frequently attribute symptom exacerbation to adverse weather, the scientific evidence for a direct link remains inconclusive. This study aimed to evaluate the association between meteorological and biometeorological factors-including the Universal Thermal Climate Index (UTCI) - and the number of low back pain cases in a large outpatient population. This retrospective, registry-based, population-level study analyzed 36,854 cases of adult LBP recorded between 2009 and 2023 from two healthcare facilities in Olsztyn and Iława. Meteorological data, including air temperature, humidity, wind speed, atmospheric pressure, and UTCI values, were sourced from a regional synoptic weather station. We conducted descriptive and multivariable statistical analyses to assess seasonal patterns and explore potential correlations between LBP case counts and environmental variables. The number of LBP cases displayed a clear seasonal pattern, with peaks in July and October and the lowest counts in February and April. However, linear correlations between daily weather parameters and LBP cases were weak (Pearson's r < 0.2). Days classified as thermally neutral (UTCI 9.1-26.0 °C) accounted for over 65% of all cases, suggesting an indirect relationship with increased physical activity during comfortable weather. Multivariable regression identified minimum and average daily temperatures as modest but statistically significant predictors of the number of LBP cases, while other meteorological factors - including UTCI - showed no meaningful effect. The years 2020-2022 marked a notable drop in LBP reporting, likely linked to behavioral changes and healthcare limitations during the COVID-19 pandemic. Meteorological conditions alone do not appear to directly drive fluctuations in daily LBP case counts. Instead, seasonal changes in human activity patterns, encouraged by thermally neutral weather, likely play a more important role. These findings highlight the importance of incorporating behavioral and occupational context when interpreting LBP trends and may inform targeted preventive strategies during peak case periods.