Journal of Ergonomics

Employee anthropometric considerations in tool design and workstation lead to workplace safety, satisfaction, ease of tool using, and prevention of musculoskeletal disorders and hazards [1]. The design of tools and workstations, without taking into account the physical dimensions and anthropometric characteristics of users, will have adverse effects on users' health [2]. Studies in Iran have shown the importance of the role of anthropometric characteristics in the design of the workstation and the reduction of occupational hazards and thus higher productivity [3-6]. Unfortunately, the variability in physical dimensions between people of different genders, races, and climatic conditions can cause problems in the design of the workplace and tools [7, 8]. Given the differences in anthropometric characteristics in different working populations and the existence of individual and regional differences, it is necessary to determine the anthropometric characteristics of employees for effective use in designing the work environment [3, 6]. These features and specifications can be used to standardize the equipment used and to create a sense of proportion between the machine and the human [7]. For this purpose, the present study was conducted to determine the anthropometric dimensions of Hormozgan Gas Department employees in order to design a standard desk and chair for working with computers based on the obtained anthropometric variables.

 

This descriptive analytical study is a cross-sectional study conducted among the employees of Hormozgan Gas Company. Anthropometric measurements were considered and performed based on the anthropometric methods and variables proposed by Fisent [9] and the Environmental Research Institute of Tehran University of Medical Sciences for Iranian workers performed by Sadeghi et al. [10]. After analyzing the descriptive statistics, the percentages were extracted by gender and the T-test was used to compare the anthropometric dimensions of men and women at a significance level of 95%. Finally, using the anthropometric tables obtained and the ergonomic design guide [9, 11, 12], ANSI / HFES 100-2007 standard [13] and the findings of previous studies [17-17], the dimensional specifications of the chair and office desk were calculated.

 

The participants in the study included 121 people (80.2% male and 19.8% female) with an average age of 35.11 and a standard deviation of 6.6 in the range of 25 to 59 years. The mean and standard deviations of the measured height were 170.7 and 8.06 cm, respectively. Of course, this average is set at 159.95 cm for women and 173.35 cm for men. In all dimensions of anthropometry, except for sitting elbow height, thigh thickness, and seat width, men's sizes are significantly higher than women's, and joint sizes cannot be used in workstation designs.

Table 1. Anthropometric results of sex-measured personnel

In the design of the chair, it should be noted that sitting with the straight back, with the upper body and neck almost vertically and in a straight line, and the legs from the legs down to the vertical, is possible [18]. The chair should be designed in such a way that the floor of the user's feet does not hang when sitting. To achieve this, the adjustable chair should be used and at a height equal to the range of the fifth and ninety-fifth percentile of the pedal height (Figure 1).

Figure 1. Schematic of seat specifications

The height of the work desk was calculated using the elbow height in the sitting position. The schematic and calculated dimensions of the office desk are shown in Figure 2.

Figure 2. Schematic specifications of office desk

The height of the seat designed in this study is estimated to be adjustable from 41.33 to 51.6 cm. This amount is considered in the office chair made by Motamedzadeh et al. [14] to be 38 to 44 and in Sharifi et al. study [15] to be 38 to 46 cm. Both studies used data from Iranian users in recent years. The standard height of adjustable seat of the office work environment is recommended in ANSI / HFES 100-2007 [13] as 38 to 56 cm. In the case of seat width, the design value of Motamedzadeh [14] and Sharifi [15] is 45 and 43 cm, respectively. This value is recommended to be at least 45 cm in the ANSI / HFES 100-2007 [13] standard, which is 46.79 cm in the present study. In this study, the height of the back was set at 56.95 cm, which was at least 45 cm in the ANSI / HFES 100-2007 standard [13] and 52 cm in the Motamedzadeh study [14] and 68 cm in Sharifi [15], all three studies followed the standards.
The height of the sitting desk designed in this study is 73.93 cm. This value is recommended in the ANSI / HFES 100-2007 standard for a fully seated desk of 72 cm and for a standing desk up to 118 cm [13]. The difference of 19 mm can be considered due to the difference in the distribution of the amount of scattering. However, according to Fisent [9], the computational error in anthropometric measurements is 2.5 cm and the difference is more tolerable. The minimum height of the space under the table to accommodate the legs in this study was calculated to be 59.47 cm and a depth of 45.7. The maximum height of the screen from the table surface to calculate the angle of zero to sixty degrees below the user's horizon is calculated to be 70.78 cm, which is equal to the recommendation of reputable authorities [13, 19].

 

The proposed anthropometric tables can be used in future studies and designs. Also, the dimensional specifications of the equipment provided can be a practical guide for designing and building an office work environment.

 

The authors appreciate the help of all those who helped them writing this article.

 

The authors declared no conflict of interest regarding the publication of this article.