Correlation of Sagittal Spinopelvic Alignment Parameters With Pain and Functional Disability in Chronic Non-specific Low Back Pain.

Introduction This cross-sectional study evaluated the correlation between sagittal spinopelvic alignment parameters and pain and disability in patients with chronic non-specific low back pain (CNSLBP). While spinopelvic parameters like pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and lumbar lordosis (LL) are key to sagittal alignment, their biomechanical relationship with functional impairment and pain in CNSLBP has not been fully quantified. Methods Ninety adults aged 21-60 years with CNSLBP were clinically and radiographically assessed. The Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) were used for clinical evaluation. Radiographic parameters (PI, PT, SS, LL, and Roussouly Type 1-4) were measured from lateral standing radiographs. Correlation and regression analyses were used to examine the relationships between these parameters and clinical scores. Results PI-LL mismatch showed a significant correlation with ODI (r = 0.29, p = 0.008) and a moderate association with VAS (r = 0.22, p = 0.06). Linear regression confirmed PI-LL mismatch as an independent predictor of disability (β = 0.251, p = 0.003). VAS was also positively correlated with ODI (r = 0.46, p < 0.001). Roussouly types were associated with structural parameters but not with clinical severity. Conclusion PI-LL mismatch is an important determinant of pain and disability in CNSLBP. The findings suggest that the impact of mismatch should be considered in accordance with an individual's pelvic incidence rather than a single fixed threshold. Future studies should investigate whether correcting the mismatch toward patient-specific targets improves clinical outcomes.