Table 1 Detailed list and explanation of all back scan parameters

Trunk length D (mm)

Spatial distance between the markers VP and DM

Trunk length S (mm)

Spatial distance between the markers VP and SP

Sagittal trunk decline (°)

Inclination of the trunk length D marked line from the perpendicular to the sagittal plane.

Tilt anteriorly (negative values) = possible lordosis

Tilt dorsally (positive values) = possible kyphosis

Frontal trunk decline (°)

Inclination of the trunk length D marked line from the perpendicular to the frontal plane.

Tilt anteriorly (negative values) = possible lordosis

Tilt dorsally (positive values) = possible kyphosis

Axis decline (°)

Deviation of the line of the area marked by the trunk length D line of the 90 ° rotated distance DL-DR

→decline between upper body and pelvis

Thoracic bending angle (°)

Deviation of the distance VP - KA from the perpendicular

Lumbar bending angle (°)

Deviation of the distance KA - LA from the perpendicular

Standard deviation lateral deviation (mm)

Root mean squared deviation of the median line of the distance VP - DM

Maximal lateral deviation (mm)

Maximum deviation of the median line of the distance VP - DM

Negative values = deviation to the left

Positive values = deviation to the right

Standard deviation rotation (°)

Root mean square deviation of surface rotation of the median line (torsion of the spinous processes of the spine)

Maximal rotation (°)

Maximum positive or negative surface rotation on the median line

Kyphosis angle (°)

In the sagittal plane measured angle between the upper inflection point of the spine at the thoracolumbar and VP inflection point IP; point of greatest negative surface decline

Lordosis angle (°)

Angle between the inflection point at DM and the thoracolumbar inflection point IP

Pelvis distance (mm)

Spatial distance between SIPS L and SIPS R.

Pelvis height (°) and (mm)

Decline of the connecting line between SIPS L and SIPS R to the horizontal in the frontal plane in degrees and millimeter

Pelvis torsion (°)

Angle between the surface normal on the two dimples SIPS L and SIPS R

Negative differential angle = Normal at point SIPS L is stronger upward as at point SIPS R

Positive difference angle = Normal at point SIPS L is stronger downward as at point SIPS R.

Pelvis rotation (°)

Rotation of the distance SIPS L – SIPS R in the transversal plane

Scapular distance (mm)

Distance between the left (AISL) and the lower right scapular angle (AISR).

Scapular height (°)

Height difference between the points AISL and AISR

Positive value = AISR higher than AISL

Negative value = AISR deeper than AISL

Scapular rotation (°)

Rotation of the distance DL-DR in the transversal plane

Scapular angle left (°)/Scapula angle right (°)

Best fit straight line on the shoulders to the horizontal. The center point of the regression line is set vertically above AISL / AISR. The greater the angle, the more caudally located the shoulder.