RESUMEN
To understand the normal lumbar spine in the sagittal plane, and the range of lumbar lordosis. This study was carried out in the Department of Anatomy, School of Medicine, Duzce University, Duzce, Turkey in the year 2005. We retrospectively reviewed T1-weighed sagittal spin-echo MRIs of the lumbar spine in 413 individuals [188 male, 225 female] aged between 13-82 years, and evaluated the angle of lumbar lordosis [ALL], sacrohorizontal angle [SHA], and lumbosacral angle [LSA]. The ALL and SHA were significantly greater in females than in males [p<0.05]. Weak, but significant correlations were detected between age and ALL, SHA, and LSA for females [p<0.05]. The LSA was significantly greater for individuals over 41 years [p<0.05] when the entire study group was considered, and it was also significantly greater for individuals over 51 years in females [p<0.05]. The LSA was significantly greater in the 7th decade than in the 3rd decade [p<0.05]. The results of this study provide insight into the sagittal alignment of the lumbar region for a Turkish population, and can serve as a reference for further clinical studies to improve the planning of spinal surgery