**Table 3.**Results of the descriptive statistical analyses (MoM±SD) of the spinal parameters in the coronal plane.

54

**Age Cohort "Middle"**

**Age Cohort "Old"**

SD 1.6 2.0 2.5 3.4 3.3 3.0 2.5 2.6 3.0 2.8 2.3 2.0 1.9 1.6 1.3 1.5 2.3 2.8 0.7

Abbreviations:

 MoM = mean of means; SD = standard  deviation;

 Sh = shoulder;

 Pel = pelvis; N = number.  0.9

 7.4

 1.6

 8.5

 3.6

 3.0 **Age Cohort "Young"** **Sex**



**Table 4.** Results of the descriptive statistical analyses (MoM±SD) of the spinal parameters in the sagittal plane.

**Age Cohort "Middle"**

**Age Cohort "Old"**

**Old Males**

MoM

SD

 - 23.5 25.0 26.4 23.2 18.1 13.0

 -

 6.9

Abbreviations:

 MoM = mean of means; SD = standard  6.1

 6.0

 4.9

 4.5

 4.7

 4.1

 4.1

 4.5

 deviation;

 Sh = shoulder;

 Pel = pelvis; N = number.  4.2

 4.2

 4.8

 4.7

 5.1

 6.0

 5.3

 5.2

 8.9  8.7

 5.2

 0.8 −4.7 −10.1 −14.6 −17.0 −17.1 −14.3 −5.7 4.1 13.7

> 2.6

 1.8

> 22.8

 15.5

> 52.4

 9.0

> 34.4

 9.1 **Age Cohort "Young"** **Sex**

**Figure 2.** Vertebral body positions in the transversal plane. Positive values represent a rotation of **Figure 2.** Vertebral body positions in the transversal plane. Positive values represent a rotation of the vertebral bodies to the left (counterclockwise), and negative values represent a rotation of the vertebral bodies to the right (clockwise). The scale of the *x*-axis is turned to enhance the intuitive visual interpretability of the results: (**Upper row**) (left picture: all participants (■, green); right picture: all female (◆, red) and all male (•, blue) participants). (**Middle row**) (left picture: all participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red); middle picture: all female participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red); right picture: all male participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red)). (**Lower row**) (left picture: all young female (◆, red) and all young male (•, blue) participants; middle picture: all middle-aged female (◆, red) and all middle-aged male (•, blue) participants; right picture: all old female (◆, red) and all old male (•, blue) participants).

◆ ●

◼ ◆ ● ● ◼ ◆ ● ◼ ◆ ● ◼ ◆ ◆ ● ◆ ● ◆ ● **Figure 3.** Vertebral body positions in the coronal plane. Positive values represent a tilt of the vertebral bodies to the left, and negative values represent a tilt of the vertebral bodies to the right. The scale of the *x*-axis is turned to enhance the intuitive visual interpretability of the results: (**Upper row**) (left picture: all participants (■, green); right picture: all female (◆, red) and all male (•, blue) participants). (**Middle row**) (left picture: all participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red); middle picture: all female participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red); right picture: all male participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red)). (**Lower row**) (left picture: all young female (◆, red) and all young male (•, blue) participants; middle picture: all middle-aged female (◆, red) and all middle-aged male (•, blue) participants; right picture: all old female (◆, red) and all old male (•, blue) participants).

◼

● ◼ ◆

◆ ●

● ◼

● ◼ ◆

◆ ◆ ●

◆ ●

◼ ◆ ● ● ◼ ◆ ● ◼ ◆ ● ◼ ◆ ◆ ● ◆ ● ◆ ● **Figure 4.** Vertebral body positions in the sagittal plane. Positive values represent a tilt of the vertebral bodies towards spinal flexion, and negative values represent a tilt of the vertebral bodies towards spinal extension. The scale of the *x*-axis is turned to enhance the intuitive visual interpretability of the results: (**Upper row**) (left picture: all participants (■, green); right picture: all female (◆, red) and all male (•, blue) participants). (**Middle row**) (left picture: all participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red); middle picture: all female participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red); right picture: all male participants of the respective age cohorts: young (•, blue), middle (■, green) and old (◆, red)). (**Lower row**) (left picture: all young female (◆, red) and all young male (•, blue) participants; middle picture: all middle-aged female (◆, red) and all middle-aged male (•, blue) participants; right picture: all old female (◆, red) and all old male (•, blue) participants.

#### 3.2.1. Descriptive Data Analysis

In the transverse plane, the spine was not in a neutral rotary position. Instead, a systematic vertebral rotation to the right side was identified from T5 to L3 among all the investigated subgroups (Figure 2 and Table 2). In the coronal plane, a systematic deviation from the neutral centerline was also apparent. The vertebrae above T5 were laterally flexed to the right side, and around the fifth thoracic vertebrae, the side of lateral flexion changed in direction to the left (Figure 3 and Table 3). In the sagittal plane, T8 was found to be in an almost neutral position, indicating that it was the thoracic kyphosis apex (Figure 4 and Table 4). The vertebrae above (C7–T7) were tilted towards spinal flexion, while the vertebrae below were positioned in spinal extension (T9–~L3). The height of the lumbar lordosis apex, meaning the reverse change in direction from spinal extension to spinal flexion, differed between the analyzed subgroups but was systematically located between L2 and L4.

*Bioengineering* **2022**, *9*, 809

**Table 5.** Results of the explorative statistical analyses (one-sample Wilcoxon signed rank test and two-way analyses of variance) of the spinal parameters in all three planes of movement.


*Bioengineering* **2022**, *9*, 809
