Table 2.

Characteristics of Morphological Variation in the Fifth Lumbar Vertebra Represented by Each Principal Component (PC1 to PC6).

Principal Component	Characteristics observed with larger principal component scores
1	Smaller cross-sectional area of the superior and inferior vertebral body surfaces
	Coronally oriented transverse process
	Longer neural arch length
	Coronally oriented facet joints
	Lower height of the anterior and posterior vertebral body
	Shorter, narrower, and downward-oriented spinous process
	Larger left-right distance of the superior and inferior articular processes
	Lower vertical distance between the superior and inferior articular processes
2	Larger cross-sectional area of the superior and inferior vertebral body surfaces
	Shorter transverse process
	Lower height of anterior and posterior vertebral body
	Shorter and narrower spinous process
3	Smaller cross-sectional area of the superior and inferior vertebral body surfaces
	Longer pedicle and neural arch length
	Larger dorsal wedge shape of the vertebral body
	Horizontally oriented spinous process
	Shorter isthmus length
4	Longer width of the superior vertebral body surface
	Shorter pedicle length
	Narrower and horizontally oriented spinous process
5	Coronally oriented transverse process
	Longer width of the inferior vertebral body surface
	Higher height of the posterior vertebral body
	Smaller dorsal wedge shape of the vertebral body
	Shorter isthmus length
6	Shorter left-right distance of the inferior articular processes
	Greater vertical distance between the superior and inferior articular processes