Sagittal lumbar lordosis and pelvic alignment in the supine, sitting, and standing positions among the middle-aged patients

Abstract

Introduction: Older adults, because of weakness in locomotion, and office workers spend most of their time in the sitting position. Kinematic analysis of the lumbar spine elucidates the causes of low back pain (LBP) while sitting, thus aiding the formulation of prevention strategies. Purpose: We investigated the difference in sagittal lumbopelvic alignment between the supine, standing, and sitting positions in middle-aged patients with chronic LBP. Methods: The lumbar lordotic (LL) angle; lumbar segmental angles, specifically L1-2, L2-3, L3-4, L4-5, and L5-S1 Cobb angles; sacral slope (SS); pelvic tilt (PT); and pelvic incidence (PI) were measured on the lateral spine in standing, supine, and sitting positions using radiographs. Results: Of the 87 participants, 47 and 40 were men and women, respectively (mean age, 56.1 ± 7.4 years). The average PI was 49.9° ± 10.0°. LL, SS, L2-3, L3-4, and L4-5 Cobb angles decreased significantly during movement from the standing to sitting position and from the standing to the supine position, while PT increased during these movements. L5-S1 Cobb angle decrease contributed the most to the change in LL when moving from the standing to sitting position. Changes in PT, LL, and L5-S1 Cobb angle when moving from the standing to the sitting position were less substantial in older participants. Conclusion: The spinopelvic sagittal parameters mostly significantly changed from the standing positions to the sitting and supine position among the middle-aged patients with chronic LBP, except for L1-2 Cobb angle and L5-S1 Cobb angle between supine and standing positions.