Civil Engineering Reference
In-Depth Information
10. Height of seat front to floor
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A simple case of anthropometric design is illustrated in Figure 8.4. The 5th percentile
female and 95th percentile male measures are illustrated for a sitting workplace. Note that
the popliteal height (from the sole of the foot to the crease under the knee) is 36 cm (14.0
in) for 5th percentile females and 49 cm (19.2 in) for 95th percentile males. These values
may actually differ slightly in different anthropometric tables. Note also that the popliteal
height (and other measures) are taken without shoes, so that for design purposes one must
add the height of the heel
FIGURE 8.4
Comparison of
anthropometric measures (cm) for a
sitting 5th percentile female and a
sitting 95th percentile male—height-
adjustable chairs and tables can be
used to compensate for these
differences.
of the shoe (about 3 cm). The appropriate range of adjustability for a chair-seat height is
then 39-52 cm (15-20.2 in). The distance from the floor to the elbow is obtained by
adding the popliteal height, sitting elbow height, and shoe height (3 cm). This measure is
57-81 cm (22-32 in) and it can be used to select appropriate table height.
As illustrated in the right-hand part of Figure 8.4, there are two different ways to
compensate for anthropometric differences. One can use either a height-adjustable chair
plus a foot rest, or a height adjustable chair plus a height-adjustable table. Both
arrangements will make it possible to support the feet and have the table at elbow height.
The height-adjustable table is more expensive than the foot rest, but it is more
comfortable to rest the feet on the floor than to use a foot rest.
In many offices (including the author's) the table height has been set once and for all.
Although it is possible to raise and lower the table height, this usually requires some
effort, and a change may not be worth it. A height-adjustable chair is rarely changed
more than once per day. For individuals who have their own workstation, ease of
adjustability is therefore not so crucial. But for people who share a workstation, for
example shift workers, adjustability becomes essential (Shute and Starr, 1984).
