Biomedical Engineering Reference
The female and male models are shown in Figs. 5.47 and 5.48 with bone
structure and gluteal and upper leg muscle groups. Mesh details of the male model
are shown in Fig. 5.49 ; the female model is meshed accordingly.
The muscle structures of the gluteal muscles are represented by three main
muscle groups, musculus gluteus maximus, musculus gluteus medius and musculus
gluteus minimus. The upper leg muscles are formed by 10 muscle groups. Separate
representation of all of these groups was not done, and all muscles were assumed
to be combined and isotropic in models BoMo1 to BoMo5.
5.3.5 B OSS -Models for Seated Posture
Ergonomics: Variable recommendations with respect to seating position and
sitting posture, in particular upper body and extremity angles, have been proposed
to improve car ergonomics (Babirat et al. 2001) and (Helbig and Jürgens 1977).
In Fig. 5.50 angles between extremities are shown for an ideal sitting posture,
(Babirat et al. 2001) and (Helbig and Jürgens 1977).
In the engineering standards DIN 33 402, current anatomical body dimensions of
individuals between the ages of 18 and 65 are specified and employed by the
automotive industry in crash dummy design. Body dimensions are categorized by
gender and are divided into four age groups: 18-25, 26-40, 41-60 and 61-65 years
of age. These literature and engineering standards have been employed in generating
the B OSS -Models for the seated body position. The joints of the spine and the
extremities and the surrounding tissue elements have been generated to adjust to any
seating scenario, (Lazarus 2009). The definition of the P50 male was used, which
was in good accordance with the body properties of the 25 year old male volunteer
participating in the data generation process, cf. Table 5.12 .
The generation procedure for the B OSS -Models in a recumbent position is
described in the following, using the example of the previously mentioned P50
Surface data: Collecting anatomical data from the seated body position in an
undeformed and unloaded tissue state is more laborious, compared to collection
from the upright or recumbent position. The generation of surface data via a
3D-laser scanner requires two steps, due to partial data extinction in covered body
parts. In the first step, the upper body was scanned with the volunteers seated on a
standard automotive seating device. The second step involved scanning the lower
body region in the upright upper body position with a flexed knee angle corre-
sponding to that in the seated position, cf. Fig. 5.51 a and b. Additional treatment
and combination of the scan data was then required to obtain the surface model
depicted in Fig. 5.51 c.