Fig 1.
Spinopelvic parameters measured.
Superior line: pelvic incidence—PI (left); pelvic tilt—PT (center); sacral slope—SS (right). Middle line: lumbar lordosis—LL (left); thoracic kyphosis—TK (left-middle); thoracolumbar alignment—TL (middle-right); C2 pelvic angle—CPA (right). Inferior line: spinosacral angle—SSA (left); sagittal vertical axis—SVA (center); L1S1 and T1S1 length (right).
Fig 2.
A) Lumbar lordosis angle measured by L3 inferior endplate to sacral endplate (L3-S1). B) Lumbar intervertebral angles: L3-L4, L4-L5, and L5-S1.
Fig 3.
Sagittal T2-weighted image to demonstrate the superior and inferior limits of MRI axial slices acquisition.
A) The white arrows point to the L3 superior endplate; the dashed arrow points the anterior margin of the S1 superior endplate. B) The white lines represent the upper and inferior limits of the block of axial slices.
Fig 4.
Superior line: Axial T1-weighted MRI at L4-L5 level with segmented lumbar muscles on Display® software.
Right (green) and left (red) sides were indicated. Left: multifidus; center: erector spinae; right: psoas. Inferior line: Axial MRI sequences used to fat infiltration extraction. Left: In-Phase image; center: Out-Phase image; right: fat map.
Table 1.
Lumbar musculature morphometric measurements expressed as mean, standard deviation (SD) and range (minimum and maximum).
Table 2.
Lumbar musculature morphometric measurements of cross sectional areas (mm2) and fat fraction (%) according to intervertebral level expressed as mean and standard deviation (SD).
Table 3.
Spinopelvic parameters expressed as mean, standard deviation (SD) and range (minimum and maximum).
Table 4.
Volumetry and fat fraction expressed as mean and standard deviation (SD) of the lumbar musculature according to gender and side.
*: Significant difference for p <0.05.
Table 5.
Correlation of anthropometric characteristics with fat fraction and volume values on lumbar musculature.
* Denotes a significant correlation (p <0.05).
Table 6.
Correlation (r) of the volume and fat fraction values on lumbar musculature with the spinopelvic parameters.
* Denotes a significant correlation (p <0.05).
Table 7.
Intraclass coefficient (ICC) and confidence interval (95% CI) for interobserver and intraobserver analysis on muscle volumes and spinopelvic parameters.