Page 182 - Anthropometry, Apparel Sizing and Design

Functional measurements and mobility restriction (from 3D to 4D scanning) 177

advantage that the scanning process is relatively fast (duration: approx. 10s/scan) and
the physical markers on the subject are easily recognizable.
The disadvantage of using a 3-D body scanner for such a measurement survey is
that the scan area is limited and, depending on the position, it can lead to severe
shadowing of individual parts of the body (Kouchi, 2014). The detectable area
amounts to 2100 750 750mm. Four lasers and eight cameras are positioned in
the four columns. The rigid setting makes it difficult to detect horizontal areas and
areas such as the armpit or crotch. Furthermore, for positions like “Bend” or
“Squat,” body parts conceal other areas. This also leads to unrecorded points. The lim-
ited recording space of the scanner means that not all positions can be scanned. There-
fore positions had to be adjusted and referred to the examined areas.
To reduce shadows the use of handheld 3-D scanners were discussed. Compared
with 3-D body scanners, they can also be used to detect areas that are concealed
by other parts of the body. This is because the device is guided manually around
the body. The method requires experience in operation. Even with adequate skill a
full-body scan takes several minutes. As a result the subject has to hold the individual
positions much longer in comparison with the 3-D body scanner. This is neither fea-
sible nor reasonable for many subjects in terms of physical condition. Due to the long
recording time, individuals may be scanned using handheld systems. For larger groups
of subjects, these scanners are not the method of choice.
For future studies in the field of functional measurements, it must be examined
whether body scanners with structured light are better suited for this usage. These
enable even shorter recording times and less shadowing than a laser scanner, since
significantly more cameras with different viewing angles can be used.

7.2.3.4 Dimensions

In total, 21 measurements were taken from each of the 93 persons in the 10 different
positions (see Table 7.1), which were taken on the 3-D scans in 10 different positions
with the aid of the measurement software ScanWorx (Human Solutions Gmbh, n.d.).
These include, alongside the primary measurements, chest girth, other girth, length,
and distance measurements. The definition of the measuring sections is basically
based on the ISO standard (ISO—International Organisation for Standardization,
1989). However, some measurement definitions had to be adjusted. The arm length
was not measured according to the standard from the acromion to the wrist bone,
but from the marker position of the “arm crease” (see Section 7.2.3.1) to the wrist
bones. This allowed the determination of the maximum arm reach in the movement
that, in connection with the change in back width, must be covered by a clothing prod-
uct. The measuring section of the upper arm circumference was also recorded differ-
ently. In accordance with standards, measurements are taken at the strongest point
directly at the transition from the shoulder to the arm. However, this rule cannot be
applied to the measurement taken by 3-D body scans. This is because of the fact that
large shadowing occurs at the transition from the shoulder to the arm, and so the mea-
surement cannot be taken comprehensively. A standard-compliant registration would
lead to measurement errors. The measurement values would be too small