Table 2.

The average differences between the real and the calculated positions of the segments (as a percentage of each spinal segment’s length) at approximation of quadratic regression.

Segment	Variant R_IR		Variant IR_R
	Training sample, %	Testing sample, %	Training sample, %	Testing sample, %
T13	7.35±2.37	7.29±1.88	10.18±3.25	12.63±2.84
L1	8.48±2.12	11.76±2.51	9.62±2.98	18.54±2.28
L2	13.24±3.14	18.09±1.50	11.90±2.67	24.17±3.03
L3	16.50±4.85	24.65±4.25	22.74±7.21	26.78±7.18
L4	18.75±5.83	30.25±5.68	27.19±9.30	38.69±9.30
L5	21.89±5.28	37.49±7.43	22.87±5.29	36.09±11.62
L6	33.60±10.88	47.00±11.84	30.75±9.14	38.24±10.38
L7	44.71±11.62	60.80±15.30	42.05±10.19	48.33±12.75
S1	71.14±17.26	74.97±19.62	67.64±12.94	59.33±13.03
S2	102.05±29.29	94.07±19.99	90.78±18.74	86.65±13.57
S3	99.14±25.66	115.87±22.55	103.51±18.57	101.71±15.18