Engineering Anthropometry - Fundamentals and Assessment Tools for Occupational Ergonomics - page 184

TABLE 9.3 Guidelines for the Conversion of Standard Measuring Postures to Functional Stances and Motions
To consider Do the following

Slumped standing or sitting Deduct 5 to 10% from appropriate height measurements

Relaxed trunk Add 5 to 10% to trunk circumferences and depths

Wearing shoes Add approximately 25 mm to standing and sitting heights: more for “height heels”

Wearing light clothing Add about 5% to appropriate dimensions

Wearing heavy clothing Add 15% or more to appropriate dimensions (note that heavy clothing may

severely reduce mobility)

Extended reaches Add 10% or more for extensive motions of the trunk

Use of hand tools Center of handle is at about 40% hand length, measured from the wrist

Forward bent head (and neck)
posture

EE line close to horizontal

Comfortable seat height Add or subtract upto 10% to or from standard seat height

Source: Adapted from Kroemer et al., Engineering Physiology. Bases of Human Factors / Ergonomics, 3rd ed., Van Nostrand

Reinhold — John Wiley & Sons, New York, NY 1997. With permission.

In spite of the military sampling bias, the data in Table 9.4 are the best available information on the
civilian North American adult population as Kroemer et al. argued in 1997. Their main reservation con-
cerns body weight, which is obviously more variable in the civilian population than in the military and,
given the current trend toward general obesity, on average is likely to be larger among the civilians. Head,
foot, and hand sizes should not differ appreciably between soldiers and civilians.
Table 9.4 gives the mean (50th percentile), as well as the standard deviation, for 36 body segments and
for body weight. This allows calculation of any percentile value of interest, as discussed earlier.
Table 9.5, Table 9.6, and Table 9.7 present, in similar fashion, descriptive data from Taiwan and Japan,
Great Britain and France, Germany and Russia.
Reliable and comprehensive information on body sizes is at hand, unfortunately, for only the few
populations listed previously. For other groups, some limited anthropometric information are avail-
able, which are compiled in Table 9.8. However, these data resulted from widely varying techniques of
data gathering, often on only small samples. This makes it doubtful that the listed statistics for mean
and standard deviation truly represent the underlying population. For most humans on earth, only
gross estimates exist that are listed in Table 9.9. The data in Table 9.8 and Table 9.9 may serve as
rough approximations of regional anthropometry, but they cannot replace exact measurements.

9.6 How to Get Missing Data

Often we design products for users about for whomwe lack exact body size or strength information. This
does not pose a great problem if the product is similar to items already in use, and if we know the users
fairly well, such as our colleagues or at least people from our own country. In this case, we can probably
take a few measurements on our acquaintances and make a “rough guestimate” of what the needed
dimensions might be.
For exact and comprehensive information, however, more than such informal information gathering is
necessary. Two avenues are open: one is to conduct a formal anthropometric survey, which is a major
enterprise and best done by qualified anthropometrists (Bradtmiller, 2000; Robinette and Daanen,
2003; Roebuck, 1995). The other option is to deduce from existing data those that we need to know.
For such approximations, several approaches are at hand as follows:

9.6.1 Estimation by “Ratio Scaling”
“Ratio scaling” (used by Pheasant in 1986 and 1996 to establish the British data partly shown in Table 9.6)
is one technique to estimate data from known body dimensions (Pheasant, 1982). It relies on the