Figure 2.

Morphological variation of the first principal component in all participants. SD: Standard deviation. Cross-sectional area of the superior (arrow 1) and inferior (arrow 2) vertebral body surfaces; transverse process orientation (arrow 3); neural arch length (arrow 4); facet joints orientation (arrow 5); height of the anterior and posterior vertebral body (arrow 6); spinous process orientation, length, and width (arrow 7); left-right distance of the superior and inferior articular processes (arrow 8); and vertical distance between the superior and inferior articular processes (arrow 9).