Table 2.

Montecarlo scenario (3000 repetitions) helixes modelling spine deformations during movement: Assessed Absolute Mean Angle Error and SD simulating marker-misplacement error along the longitudinal direction.

Helix	True Angle	Mean of Estimated Angles	Absolute Mean Angle Error	Angle Error SD
1 (A = 2.5, f = 2.5)	42.47	42.27	0.20	0.45
1	42.81	43.57	0.77	0.58
1	21.43	20.17	1.25	0.30
2 (A = 3.27, f = 2.47)	53.46	53.11	0.35	1.67
2	53.87	54.75	0.88	1.70
2	24.73	22.97	1.76	0.88
3 (A = 3.96, f = 2.40)	61.47	61.29	0.18	0.47
3	61.90	62.35	0.45	0.66
3	20.90	20.65	0.25	0.20
4 (A = 4.52, f = 2.29)	65.78	65.06	0.73	0.32
4	66.16	65.78	0.38	0.86
4	11.61	11.16	0.45	0.60
5 (A = 4.87, f = 2.15)	66.51	65.34	1.17	0.39
5	66.87	65.88	0.99	0.56
6 (A = 5.0, f = 2.0)	63.90	63.54	0.36	0.40
6	64.21	64.10	0.11	0.49
7 (A = 4.87, f = 1.84)	58.73	58.87	0.15	0.55
7	56.06	55.55	0.51	1.46
8 (A = 4.52, f = 1.70)	51.54	51.40	0.14	0.31
8	42.17	41.59	0.57	0.70
9 (A = 3.96, f = 1.59)	43.24	42.86	0.38	0.44
9	28.39	27.73	0.66	0.40
10 (A = 3.27, f = 1.52)	34.70	34.49	0.20	0.92
10	18.78	17.95	0.83	0.98
11 (A = 2.5, f = 1.5)	26.42	23.37	3.05	3.38
11	13.25	12.45	0.80	1.65
Mean Value	44.67	44.16	0.68	-
Standard Deviation	18.67	18.95	0.63	-