Figure 2.

The CBP^® Full-spine Normal Model is the path of the posterior longitudinal ligament through the posterior body margins. It is composed of separate ellipses in the different spinal regions (cervicals, thoracics, & lumbars). It has near perfect sagittal balance of vertical alignment of C1-T1-T12-S1. This model provides normal sagittal plane curves and normal values for all segmental angles and global angles. The sagittal curves have points of inflection (mathematic term for change in direction from concavity to convexity) at inferior of T1 and inferior of T12. Reprinted with permission from Harrison DE et al. Spinal Biomechanics for Clinicians. Vol. I. Evanston, WY: Harrison CBP^® Seminars, Inc., 2003.