2020 Volume 11 Issue 5 Pages 842-847
Introduction: Spinopelvic alignment in the sitting position remains unclear. We investigated the differences in spinopelvic alignment in the standing and sitting positions in outpatients.
Methods: We enrolled a total of 84 outpatients with low back pain (43 men, 41 women; average age: 64.4 years). Patients with a history of spinal surgery were excluded. Whole-spine lateral radiographs were obtained for all patients in the standing and sitting positions without using a backrest. The sagittal vertical axis (SVA), L1-S1 lumbar lordosis (LL), sacral slope (SS), and pelvic incidence (PI) were measured. Patients with ΔSS of <5° (change in SS between the standing and sitting positions) were categorized as the group showing lesser pelvic retroversion. Statistical analysis was performed using unpaired t-test and chi-square test. The SPSS software (version 23.0; IBM, Armonk, NY, USA) was used for statistical analysis. P-values of < 0.05 were considered statistically significant.
Results: The group with lesser pelvic retroversion included 28 patients (33%) and that with pelvic retroversion included 56 patients (77%). In the group with lesser pelvic retroversion, there were primarily women, PI was significantly lower, SVA significantly increased from the standing to sitting positions (P < 0.05), and change in LL was significantly smaller (P < 0.01).
Conclusions: An anterior trunk tilt compensates for the lower reduction in LL in patients with lesser pelvic retroversion from the standing to sitting positions.
