BioMed Research International

Research Article

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

Table 2

Intraclass correlation coefficients and 95% confidence intervals for scans completed with the participant in a stationary position between scans (ICC-SBS), with participant repositioning between scans (ICC-R), and between days (ICC-BD).


Spine shape parameter by subgroup	Intraclass correlation coefficient
Spine shape parameter by subgroup	ICC-SBS¹		ICC-R²		ICC-BD¹

Distance measurements
Trunk length VP-DM, (mm)	0.99	(0.98–0.99)	0.99	(0.98–1.00)	0.98	(0.96–0.99)
Trunk length VP-SP, mm	0.97	(0.96–0.98)	0.96	(0.93–0.98)	0.96	(0.93–0.97)
Dimple distance DL-DR, (%)	0.95	(0.91–0.97)	0.93	(0.87–0.95)	0.93	(0.89–0.96)
Dimple distance DL-DR, (mm)	0.92	(0.86–0.95)	0.89	(0.81–0.93)	0.90	(0.83–0.93)
Trunk length VP-SP, (%)	0.71	(0.60–0.80)	0.60	(0.41–0.73)	0.63	(0.48–0.74)
Trunk and pelvis imbalances
Sagittal imbalance VP-DM, (°)	0.93	(0.89–0.96)	0.92	(0.85–0.95)	0.88	(0.80–0.92)
Sagittal imbalance VP-DM, (mm)	0.93	(0.89–0.96)	0.91	(0.84–0.95)	0.87	(0.80–0.92)
Pelvic inclination (dimples) (°)	0.93	(0.89–0.95)	0.92	(0.86–0.95)	0.85	(0.76–0.91)
Pelvic obliquity, (mm)	0.85	(0.77–0.90)	0.84	(0.73–0.90)	0.78	(0.66–0.85)
Pelvic obliquity (°)	0.83	(0.75–0.89)	0.82	(0.70–0.89)	0.76	(0.63–0.83)
Pelvic torsion DL-DR, (°)	0.74	(0.64–0.82)	0.68	(0.51–0.79)	0.60	(0.44–0.71)
Pelvis rotation, (°)	0.73	(0.63–0.81)	0.61	(0.42–0.74)	0.60	(0.44–0.71)
Coronal imbalance VP-DM, (mm)	0.72	(0.61–0.80)	0.69	(0.52–0.80)	0.60	(0.45–0.71)
Coronal imbalance VP-DM, (°)	0.71	(0.60–0.79)	0.67	(0.50–0.79)	0.59	(0.44–0.70)
Location of postural reference points
Inflection point ILS, (mm)	0.97	(0.95–0.98)	0.97	(0.94–0.98)	0.95	(0.92–0.97)
Lordotic apex LA, (mm)	0.97	(0.95–0.98)	0.97	(0.93–0.98)	0.94	(0.90–0.96)
Flèche lombaire, (mm)	0.95	(0.92–0.97)	0.95	(0.91–0.97)	0.92	(0.86–0.95)
Kyphotic apex KA, (mm)	0.94	(0.91–0.96)	0.95	(0.90–0.97)	0.89	(0.82–0.93)
Flèche cervicale, (mm)	0.94	(0.90–0.96)	0.95	(0.91–0.97)	0.90	(0.83–0.93)
Flèche cervicale (VP), (mm)	0.92	(0.88–0.95)	0.93	(0.87–0.96)	0.86	(0.78–0.91)
Inflection point ITL, (mm)	0.93	(0.89–0.96)	0.92	(0.86–0.95)	0.91	(0.85–0.94)
Inflection point ICT, (mm)	0.82	(0.72–0.88)	0.84	(0.73–0.90)	0.76	(0.64–0.84)
Spinal curve angles
Pelvic inclination (symm. line), (°)	0.96	(0.94–0.98)	0.97	(0.94–0.98)	0.92	(0.86–0.95)
Lordotic angle T12-DM, (°)	0.95	(0.92–0.97)	0.94	(0.89–0.96)	0.92	(0.86–0.95)
Lordotic angle ITL-DM, (°)	0.94	(0.91–0.96)	0.94	(0.89–0.96)	0.90	(0.84–0.94)
Kyphotic angle ICT-ITL (max), (°)	0.94	(0.90–0.96)	0.96	(0.92–0.97)	0.92	(0.86–0.95)
Lordotic angle ITL-ILS (max), (°)	0.92	(0.88–0.95)	0.91	(0.83–0.94)	0.87	(0.79–0.91)
Kyphotic angle VP-T12, (°)	0.91	(0.85–0.94)	0.96	(0.92–0.98)	0.89	(0.82–0.93)
Kyphotic angle VP-ITL, (°)	0.91	(0.86–0.94)	0.95	(0.91–0.97)	0.89	(0.82–0.93)
Spinal deviation
Apical deviation VP-DM (max), (mm)	0.82	(0.73–0.88)	0.82	(0.70–0.89)	0.77	(0.66–0.85)
Apical deviation VP-DM (+max), (mm)	0.84	(0.76–0.90)	0.85	(0.74–0.90)	0.79	(0.68–0.86)
Apical deviation VP-DM (rms), (mm)	0.81	(0.72–0.87)	0.79	(0.65–0.86)	0.72	(0.59–0.81)
Apical deviation VP-DM (−max), (mm)	0.75	(0.65–0.83)	0.71	(0.55–0.81)	0.64	(0.50–0.75)
Apical deviation VP-DM (amplitude), (mm)	0.78	(0.68–0.85)	0.74	(0.59–0.84)	0.68	(0.54–0.78)
Vertebral rotation (max), (°)	0.73	(0.62–0.81)	0.69	(0.53–0.80)	0.68	(0.55–0.78)
Vertebral rotation (+max), (°)	0.71	(0.59–0.79)	0.66	(0.49–0.78)	0.62	(0.48–0.73)
Vertebral rotation (amplitude), (°)	0.71	(0.60–0.79)	0.73	(0.57–0.82)	0.59	(0.44–0.70)
Vertebral rotation (−max), (°)	0.71	(0.58–0.79)	0.69	(0.53–0.80)	0.65	(0.51–0.75)
Trunk torsion, (°)	0.63	(0.50–0.73)	0.67	(0.51–0.78)	0.56	(0.41–0.67)
Vertebral rotation (rms), (°)	0.53	(0.41–0.63)	0.49	(0.31–0.63)	0.42	(0.27–0.55)

¹ICC-SBS and ICC-BD were calculated from the stationary between scans collected over 5 days. ²ICC-R was calculated from the repositioning scans collected on day 5. 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; rms: root mean square; SP: sacral point; VP: vertebral prominens.