Subjective Scales of Effort and Workload Assessment - Fundamentals and Assessment Tools for Occupational Ergonomics - page 735

TABLE 37.2 Borg's CR10 Scale with “P” Representing Perception
0 Nothing at all “No P”

0.3
0.5 Extremely weak Just noticeable

1 Very weak

1.5
2 Weak Light

2.5
3 Moderate

4
5 Strong Heavy

6
7 Very strong

8
9
10 Extremely strong “Max P”

Absolute maximum Highest possible

*

Source: Adapted from Borg, G.A. (1982). Med Sci Sports Exerc, 14, 377-381.
With permission.

studies showed that different levels of physical activity, gender, age and conditions such as asthma, blind-
ness, and cardiac disease do not affect the validity of this scale (Hampson et al., 2001). The CR10 scale has
also been correlated with physiological measures, such as heart rate, blood lactate, and muscle lactate,
supporting the validity of the scale (Borg, 1985; Borg et al., 1987; Noble and Robertson, 1996).
Most of the differences in RPE responses are attributed to physiological factors (oxygen uptake and
heart rate, ventilation and respiration rate, electromyographic (EMG) measures, perspiration rate,
blood lactate) (Borg, 2001). However, quite large variance in RPE responses may be explained by psycho-
logical factors such as personality and rating behavior, emotional and motivational factors. Morgan
(1973) demonstrated that subjects who are neurotic, anxious, and depressed have difficulties with accu-
rate rating of perceived exertion. It was also revealed that preferred exercise intensity was higher for extra-
verted subjects than for introverted subjects, and supported the hypothesis that extraverts suppress
painful stimuli (Morgan, 1973).
The overwhelming focus on these scales application has been the use of RPE for regulation of exercise
intensity and exercise prescription (Russell, 1997). The main application of scales of perceived exertion in
human factors research is in the assessment of physical workload (Borg, 2001). The RPE scale is often used
to evaluate the exertion and difficulty of a work task in order to compare different performance techniques
or to adjust the task to specific population group (age, gender, or handicapped). Perceived exertion
has been used in different context to evaluate the level of physical effort required to complete different
tasks (Shepard, 1994). The Borg CR10 scale was also used to rate physical exertions of truck drivers
during heavy operations (Johansson and Borg, 1993). In a package delivery industry, the scale of perceived
exertion was used to estimate the amounts of load that correspond to various levels of load heaviness
(Genaidy et al., 1998). Psychophysical assessments were also applied to investigate the perceived physical
effects of resident-transferring methods on nursing assistants, and to determine which method minimizes
psychophysical stress (Zhuang et al., 2000). Ratings of perceived exertions also have been used to
determine appropriate work design parameters, for example, efficient working postures, task frequency,
work capacity, and tool assessment (Pandolf et al., 1978; Legg et al., 1997; Olendorf and Drury, 2001).

37.3.2 Other Scales of Perceived Effort
37.3.2.1 Fleishman Index of Perceived Physical Effort
Hogan and Fleishman (1979) analyzed perception of physical effort for a wide range of occupational
tasks. Based on the Borg RPE scale, they developed a category scale for assessment of perceived
effort during job task performance. The proposed index (Table 37.3) of perceived physical effort is a