Table 2.

Division of studied population according to the classificatory 3-DEMO parameter "Direction".

Classification	Limits	Scoliosis	Hyperkyphosis	Scoliosis & Hyperkyphosis	Normals
Left	Angle < -9.1	50.0%	0.0%	25.0%	0.0%
Right	Angle > 13.1	9.8%	8.7%	50.0%	5.0%
Parallel	-9.1 < angle < 13.1	40.2%	91.3%	25.0%	95.0%
Chi-Square test		P < 0.05

The Direction classificatory parameter is the angle between the AP spinal axis and the AP normal spinal axis (abscissa); it was defined as Direction because it is as if the pathological spine had changed its normal postero-anterior direction with respect to the pelvis, rotating clockwise or anticlockwise.