Classification of the Normal Variation in the Sagittal Alignment of the Human Lumbar Spine and Pelvis in the Standing Position

In Brief Study Design. A prospective radiographic study of 160 volunteers without symptoms of spinal disease was conducted. Objectives. The objective of this study was to describe, quantify, and classify common variations in the sagittal alignment of the spine, sacrum, and pelvis. Summary of Background Data. Previous publications have documented the high degree of variability in the sagittal alignment of the spine. Other studies have suggested that specific changes in alignment and the characteristics of the lumbar lordosis are responsible for degenerative changes and symptomatic back pain. Methods. In the course of this study, anteroposterior and lateral radiographs of 160 volunteers in a standardized…