Associations between potentially modifiable clinical factors and sagittal balance of the spine in older adults from the general population

Purpose Spinal sagittal balance is associated with back pain and quality of life. Enhancing understanding of the clinical factors associated with sagittal balance is essential for guiding the development of effective non-operative treatment. We aimed to evaluate the associations between spinal sagittal balance and potentially modifiable clinical factors and interactions between current back pain and the evaluated clinical factors. Methods We conducted a cross-sectional study where sagittal alignment, measured radiographically by EOS, was defined by sagittal vertical axis (SVA). The clinical factors included non-radiographic (NR) lumbar lordosis angle, balance (Berg balance scale), hip and back extension range of motion (ROM) and extensor strength, and back pain. Pearson's correlation coefficients and multivariable regression analyses were conducted in 63 adult participants (70% female, mean age 73 (SD 8.6) years) from the general population. Results We identified correlations between SVA and age (r = 0.4, p < 0.001), body mass index (BMI) (r = 0.3, p = 0.008), balance (r = - 0.5, p < 0.001) and NR lumbar lordosis angle (r = - 0.5, p < 0.001). The final model (R-2 = 58%) identified that, after controlling for age and BMI, larger SVA was associated with lower NR lumbar lordosis (R-2 = 15%, p < 0.001), poorer balance (R-2 = 7%, p = 0.02), greater hip extensor strength (R-2 = 4%, p = 0.053), and among people with back pain, NR lumbar extension ROM (R-2 = 3%, p = 0.034). Hip ROM and lumbar strength were not significant. Conclusion Reduced NR lumbar lordosis magnitude and ROM, balance and hip strength are associated with SVA; however, it is unclear if these factors are compensatory, contributing, or modifiable. Hence, future longitudinal studies are needed.