Objective: The primary purpose of this study was to determine whether conventional anthropometric databases of the U.S. general population are applicable to the population of U.S. electric utility ...field-workers.
Background: On the basis of anecdotal observations, field-workers for electric power utilities were thought to be generally taller and larger than the general population. However, there were no anthropometric data available on this population, and it was not known whether the conventional anthropometric databases could be used to design for this population.
Method: For this study, 3 standing and 11 sitting anthropometric measurements were taken from 187 male field-workers from three electric power utilities located in the upper Midwest of the United States and Southern California. The mean and percentile anthropometric data from field-workers were compared with seven well-known conventional anthropometric databases for North American males (United States, Canada, and Mexico).
Results: In general, the male field-workers were taller and heavier than the people in the reference databases for U.S. males.The field-workers were up to 2.3 cm taller and 10 kg to 18 kg heavier than the averages of the reference databases.
Conclusion: This study was justified, as it showed that the conventional anthropometric databases of the general population underestimated the size of electric utility field-workers, particularly with respect to weight.
Application: When designing vehicles and tools for electric utility field-workers, designers and ergonomists should consider the population being designed for and the data from this study to maximize safety, minimize risk of injuries, and optimize performance.
Most office chairs have a backrest that is wider at the shoulders than at the hips. Recently, a new office chair was developed that has a backrest that is narrower at the shoulders and wider at the ...hips (upwardly tapered backrest). The upwardly tapered backrest should allow users to increase their ventilatory efficiency, compared to a conventional, wide backrest. This new backrest design will hypothetically allow a user to retract their scapulae, increase expansion of the chest cavity, thus allowing the lungs more space to expand. Specific measures of improved ventilatory efficiency are an increase in tidal volume (Vt - liters/breath) and a decrease in respiratory rate (RR - breaths/min). Ventilatory and cardiovascular metabolic variables were measured from 31 office workers sitting in 2 chairs (conventional and upwardly tapered). The Cortex Metamax 3B system (Leipzig, Germany) was used to measure V˙O2, RR, Vt and heart rate (HR - beats per min). Each participant performed 8 tasks in each chair. The tasks included typing, searching the internet, creating a spreadsheet, and watching a movie. Physiologic data were collected throughout testing. The subjects were blinded to which chair the test chair was. Results indicated no significant differences in users' RR and Vt between the two chairs, but the users did have a significantly lower HR when they sat in the chair with the upwardly tapered backrest (3 to 7 bpm less). Heart rate has been shown to be a risk factor of heart disease, and thus the test chair could reduce the impact of a risk factor of heart disease in office workers. Analysis of subjective assessment data did not show any overall preference for either chair.
