Reliability of the DIERS Formetric 4D Spine Shape Parameters in Adults without Postural Deformities

Table 3

Within-day and between-day mean, standard deviation (SD), standard error of measurement (SEM), and smallest detectable change (SDC).

Spine shape parameter by subgroup	Mean	SD	Within-day^1 (single scan)			Between-day^2 (single scan)			Within-day (6 scans)			Between-day (6 scans)
			SEM	SEM (%)^3	SDC	SEM	SEM (%)	SDC	SEM	SEM (%)	SDC	SEM	SEM (%)	SDC
Distance measurements
Trunk length VP-DM, (mm)	466.00	33.30	3.10	0.67	8.59	5.22	1.12	14.47	1.83	0.39	5.07	4.60	0.99	12.75
Trunk length VP-SP, (mm)	515.18	33.50	6.62	1.28	18.35	7.36	1.43	20.40	3.55	0.69	9.84	5.10	0.99	14.13
Trunk length VP-SP, (%)	110.56	1.42	1.32	1.19	3.66	1.17	1.06	3.24	0.68	0.62	1.88	0.65	0.59	1.80
Dimple distance DL-DR, (mm)	97.32	10.56	3.87	3.98	10.73	3.91	3.99	10.84	2.65	2.72	7.34	2.86	2.92	7.93
Dimple distance DL-DR, (%)	20.96	2.91	0.84	4.01	2.33	0.87	4.12	2.41	0.59	2.81	1.64	0.66	3.13	1.83
Trunk and pelvis imbalances
Sagittal imbalance VP-DM, (°)	3.17	2.18	0.65	NA	1.80	0.76	NA	2.11	0.35	NA	0.97	0.53	NA	1.47
Sagittal imbalance VP-DM, (mm)	26.23	17.66	5.40	NA	14.97	6.36	NA	17.63	2.84	NA	7.87	4.43	NA	12.28
Coronal imbalance VP-DM, (°)	0.15	0.66	0.46	NA	1.27	0.52	NA	1.44	0.30	NA	0.83	0.38	NA	1.05
Coronal imbalance VP-DM, (mm)	1.29	5.62	3.85	NA	10.67	4.38	NA	12.14	2.45	NA	6.79	3.21	NA	8.90
Pelvic obliquity, (°)	−0.17	2.92	1.42	NA	3.94	1.67	NA	4.63	0.94	NA	2.61	1.28	NA	3.55
Pelvic obliquity, (mm)	−0.12	5.13	2.36	NA	6.54	2.73	NA	7.57	1.52	NA	4.21	2.04	NA	5.65
Pelvic torsion DL-DR, (°)	−0.07	1.95	1.55	NA	4.30	1.68	NA	4.66	0.92	NA	2.55	1.19	NA	3.30
Pelvic inclination (dimples), (°)	17.89	5.64	1.77	NA	4.91	2.41	NA	6.68	1.16	NA	3.21	2.01	NA	5.57
Pelvis rotation, (°)	−0.33	2.22	1.67	NA	4.63	1.61	NA	4.46	0.87	NA	2.41	0.81	NA	2.24
Location of postural reference points
Inflection point ICT, (mm)	4.08	9.02	4.12	NA	11.42	4.53	NA	12.55	2.83	NA	7.84	3.42	NA	9.48
Kyphotic apex KA, (mm)	−190.25	23.24	5.45	2.86	15.10	7.95	4.18	22.03	3.33	1.75	9.23	6.65	3.50	18.43
Inflection point ITL, mm	−309.66	32.31	9.03	2.92	25.03	10.19	3.29	28.24	6.47	2.09	17.93	8.01	2.59	22.20
Lordotic apex LA, (mm)	−387.13	32.40	6.30	1.63	17.46	7.71	1.99	21.37	3.82	0.99	10.59	5.92	1.53	16.41
Inflection point ILS, (mm)	−462.73	42.02	7.44	1.61	20.62	9.12	1.97	25.28	5.07	1.10	14.05	7.45	1.61	20.65
Flèche cervicale, mm	74.42	16.49	3.85	5.17	10.67	5.84	7.98	16.19	1.92	2.58	5.32	4.83	6.60	13.39
Flèche lombaire, (mm)	37.53	12.18	2.84	7.57	7.87	4.29	11.40	11.89	1.53	4.08	4.24	3.58	9.52	9.92
Flèche cervicale (VP), (mm)	48.17	13.19	3.72	7.72	10.31	5.52	11.67	15.30	1.96	4.07	5.43	4.54	9.60	12.58
Spinal curve angles
Kyphotic angle ICT-ITL (max), (°)	48.47	8.32	1.92	3.96	5.32	2.55	5.28	7.07	1.15	2.37	3.19	2.06	4.27	5.71
Kyphotic angle VP-ITL, (°)	46.66	7.91	1.86	3.99	5.15	2.65	5.69	7.34	1.12	2.40	3.10	2.21	4.75	6.12
Kyphotic angle VP-T12, (°)	43.10	7.59	1.64	3.81	4.55	2.35	5.47	6.51	0.99	2.30	2.74	1.96	4.57	5.43
Lordotic angle ITL-ILS (max), (°)	35.42	7.55	2.48	7.00	6.87	3.41	9.47	9.45	1.53	4.32	4.24	2.82	7.83	7.82
Lordotic angle ITL-DM, (°)	33.50	8.11	2.07	6.18	5.74	2.98	8.73	8.26	1.28	3.82	3.55	2.52	7.38	6.98
Lordotic angle T12-DM, (°)	29.94	8.39	2.13	7.11	5.90	2.98	9.76	8.26	1.30	4.34	3.60	2.47	8.09	6.85
Pelvic inclination (symm. line), (°)	19.68	7.27	1.47	7.47	4.07	2.43	12.10	6.73	0.98	4.98	2.72	2.16	10.76	5.99
Spinal deviation
Vertebral rotation (rms), (°)	3.78	0.93	1.02	26.98	2.83	0.96	25.83	2.66	0.69	18.25	1.91	0.65	17.49	1.80
Vertebral rotation (max), (°)	1.98	6.02	3.98	NA	11.03	3.99	NA	11.06	2.80	NA	7.76	2.96	NA	8.20
Vertebral rotation (+max), (°)	5.68	2.79	2.10	NA	5.82	2.12	NA	5.88	1.45	NA	4.02	1.55	NA	4.30
Vertebral rotation (−max), (°)	−4.51	2.40	1.59	NA	4.41	1.58	NA	4.38	1.07	NA	2.97	1.13	NA	3.13
Vertebral rotation (amplitude), (°)	10.23	2.41	1.60	15.64	4.43	1.87	18.47	5.18	1.10	10.75	3.05	1.46	14.42	4.05
Trunk torsion, (°)	3.17	2.89	2.21	NA	6.12	2.37	NA	6.57	1.79	NA	4.96	1.98	NA	5.49
Apical deviation VP-DM (rms), (mm)	5.43	2.49	1.27	23.39	3.52	1.37	25.42	3.80	0.84	15.47	2.33	1.00	18.56	2.77
Apical deviation VP-DM (max), (mm)	4.26	8.69	4.01	NA	11.11	4.79	NA	13.28	2.64	NA	7.32	3.74	NA	10.37
Apical deviation VP-DM (+max), mm	8.04	5.13	2.10	26.12	5.82	2.34	29.43	6.49	1.44	17.91	3.99	1.81	22.77	5.02
Apical deviation VP-DM (−max), (mm)	−4.62	2.92	1.80	38.96	4.99	2.22	47.72	6.15	1.17	25.32	3.24	1.74	37.40	4.82
Apical deviation VP-DM (amplitude), (mm)	12.70	4.43	2.37	18.66	6.57	2.69	21.29	7.46	1.55	12.20	4.30	2.02	15.99	5.60

¹Within-day SEM, SEM%, and SDC were calculated using repositioning data collected on day 5. ²Between-day SEM, SEM%, and SDC were calculated using the first scan from the first 4 days and the 6 repositioning scans collected on day 5. ³SEM% was calculated for spine shape parameters that report only positive or only negative values. Abbreviations: DL: sacral dimple left; DM: middle point between DL and DR; DR: sacral dimple right; ICT: cervicothoracic transition point; ILS: lumbosacral transition point; ITL: thoracolumbar transition point; KA: kyphotic angle; LA: lordotic angle; NA: not applicable; rms: root mean square; SP: sacral point; VP: vertebral prominens.