The three published volumes of the Atlas of Ergonomics for Vietnamese in working age were compiled over 15 years (from 1982-1997), boasting a comparatively full range of anthropometric features for the research, design and evaluation of ergonomics comparable to ergonomics researches in the world. The scientificity and practicality of these volumes are not only highly appreciated by domestic scientists, but also gathered the interest of some international scientists and technologies. According to the growth law, for every 10-15 years, the stature and physical strength of the population will change due to the advance of living conditions. In fact, the anthropometric characteristics of the Vietnamese people today are highly different from those of 30 years ago, thus the development of an anthropometric Atlat for the purpose of research, design and evaluation of ergonomics in Vietnam is mandatory.
Based on the aforementioned issues, researchers of VNNIOSH have conducted studies with the aim of compiling an anthropometric Atlas of static and dynamic ergonomics for Vietnamese in the working age within the period 2017-2019.
Research subjects are Vietnamese people of working age (16-60 years old), possesing normal physique, working in the industry, agriculture; students and freelance workers in the Northern, Central, and Southern Areas of Vietnam. Subjects were divided into 5 age groups (16-19, 20-29, 30-39, 40-49, 50-59); 2 sexes (male and female); 3 regions (Northern, Central, Southern). The project was able to obtain measurements of 5,148 subjects consisting of 2,531 men and 2,617 women.
The technique employed to measure the static anthropometric indicators and movement range of joints complies with the measurement method applied in the human anthropometric Atlas of Vietnamese in working age - Static anthropometric data -1986 [1], anthropometric Atlas of Vietnamese in working age - anthropometric data on joints’movement range, 1997 [3], TCVN5781: 2009, TCVN7488: 2005 (ISO 7250: 1996), ISO 7250-1: 2008. Criteria applied to the measurement of arms’ range of movements according to the 90 degree vectors are implemented only in Northern and Southern areas, according to the anthropometric Atlas of Vietnamese in working age - dynamic anthropometric data of arms’ range of movement [2].
The Atlas used the linear interpolation method to interpolate the anthropometric indicators closely correlated with linearity (r> 0.7) with the basic criteria applied according to the first degree equation y = ax + b. In which: y is the anthropometric indicator that needs to be interpolated, a is the coefficient (the ratio of the indicator that needs to be interpolated with the closely correlated basic criterion calculated from the published Atlats), x is the variable (the updated measurement value of the basic indicator), b is a constant and is equal to 0.
Results of static anthropometric measurements
Based on the results of measuring and interpolating 136 static anthropometric indicators, the study was able to compile 136 tables of static anthropometric characteristics of the Vietnamese in working age of period 2017-2019. Analysis results of height when standing and weight are important criteria for the growth and development of the Vietnamese stature in the current period. The measurement lead to remarks as follows:
The current average height of Vietnamese men is 164.6 ± 5.8cm and the female is 154.4± 4.8cm. Thus, Vietnamese people possess average body height of the human kind. The difference in height between Vietnamese men and women (above and below 10cm) is also within popular limits in the world.
The average height when standing between men and women in the three regions does not significantly vary. The difference in average height when standing in the same age group between regions is not statistically significant (t <1.96). This is a far cry from 30 years ago, when the northerners were significantly lower than the southerners of many age groups.
Results of the body measurements showed that Vietnamese men had an average body measurement of 52.8 ± 0.2 and women’s were 52.9 ± 0.3. Thus, the Vietnamese people in working age have an upper body type that completely belongs to the group of people with long body. This deserves special attention when receiving machines and technological lines produced in European and American countries in technology transfer.
The average body weight of the Vietnamese adult male nowadays is 59.2 ± 8.9 kg and that of the female is 50.8 ± 6.6 kg, the difference between male and female is about 8.4 kg, bringing about a statistical significance (t> 3.29). The difference in male body weight between regions by age group ranges from 1.8 ÷ 3.0kg for men and is 1.0 ÷ 2.8kg for women. The difference in body weight between regions was statistically significant for 5 age groups and for many other age groups (t> 1.96). The weight between age groups ranges from 0.8 to 3.7 kg for men and from 0.4 to 3.5 kg for women. Weight tends to increase in direct proportional to age, and then decreases in the age group 50-59. The body mass index (BMI) of Vietnamese men at working age is currently 21.8 ± 2.9 and 21.3 ± 2.6 for women. According to the World Health Organization's classification for Asians, Vietnamese men and women currently possess normal BMI. Compared to results in the 1986 Atlas, the body weight of Vietnamese in working-age of the period 2017-2019 differs from the results published in the 1986 issue (increased by 10.6 kg for men and 6.5 kg for women).
Some other anthropometric indicators have average measurements that are different from those of the 1986 issue such as height, weight, butt width, leg length… Some indicators possess peak measurements in the age group of 16-19 and 20-29, and then gradually decrease as the age increases. Many indicators possessing average measurements which tend to be equal in northern and southern areas (such as height when standing), which is also different from the 1986 Atlas (the tendency of increasing gradually from north to south). The difference between regions and age groups in some indicators are statistically significant.
* Results of dynamic anthropometric measurements for joints’ range of movement
Results of measurement and interpolation for 50 indicators joints’ range of movement divided into 03 regions (Northern, Central and Southern), by sex (male, female), by age groups (16-19, 20-29, 30-39, 40- 49, 50-59) showed that:
The difference in joints’ range of movement in people living in the Northern, Central and Southern areas is not apparent in both men and women. Regional differences were not statistically significant. The difference in the measurement of joints’ range of movement between men and women did not develop in a certain direction. There are criteria with values higher in men than women and vice versa. There are indicators with average values that are not significantly different between men and women (t <1.96), but many indicators have a quite large difference (t> 1.96). Measurements of joints’ range of movement for Vietnamese men and women tend to decrease gradually from young age to older ages. The absolute value of the t-test between adjacent ages is smaller than that of the distant ages, i.e the difference is statistically significant with a higher probability increase. Compared with the values for joints’ range of movements in the 1997 Atlas, the ones of the period 2017-2019 has not changed much.
* Results of dynamic anthropometric measurements for the arms’ range of movement
Results of the measurement and interpolation for the arms’ range of movement on 9 horizontal planes (-48, -36, -24, -12, zero, +12, +24, +36, +48 degree) in 4 age classes (16-19, 20-29, 30-39, 40-49) of two regions (the Northern and the Southern area with n = 2873 people) showed that: at different altitudes, the arms’ range of movement, especially the opposite side (the left to the right arm vice versa) reaches different peak values. On the -24, -12, and zero degree horizontal surfaces, the arm reach usually reaches an inverse angle of 60 degree. These are the horizontal surfaces on which the reach of the arm extends the widest to the opposite side. In contrast, on the -48 degree horizontal plane, the subjects only reached an inverse angle of 0 degree (for men) or 15 degree (for women).
Figure Hands’ range of movement in height of 12cm
As the average height when standing of males and females in Southern and Northern areas does not significantly different in all age groups (t <1.96), the average values of arms’ range of movement of Southerner is higher than that of the Northerners, but the difference is not statistically significant (| t | <1.96) in all 4 age groups, in both the right and left arm, for both men and women.
The overall tendency is that the range of movement of the right arm is greater than that of the left hand, but this difference is not much. The value of t-test for arms’ range of movement in men and women of all ages in both the southern and northern area classes do not exceed 1.96, which means the difference is not statistically significant.
Similar to the anthropometric characteristics, arms’ range of movement yield highest value in the age group of 20-29, followed by the age group of 30-39 and the age group of 40-49. That trend is also demonstrated in the value of arms’ range of movement measured on many spatial coordinates in men and women of both the Northern and the Southern area. The absolute value of the t-test between adjacent age groups is smaller than that of the distant age groups, i.e the difference is statistically significant with a higher probability of increase.
The range of movement of men’s arms is 5-7cm greater than that of women. The difference in the range of movement between men and women’s arms is an authentic and statistically significant feature at the highest probability level (t> 3.26).
Tracking the measurement of arms’ range of movement on the vertical surface showed that the measurement gradually increases from top to bottom, peaked at -12cm, then steadily decreases. This remark is consistent with the anatomical posture as the arms, forearms and hands placed on zero degree and -12cm surface all head to the same direction. In addition, the measurements on the lower surfaces (negative side versus zero side) are greater than the measurements on the symmetrical horizontal surface above.
Conclusion
- The project has completed the statistical processing and measurement of static and dynamic anthropometric indicators of more than 5,148 men and women in working age living in the Northern - Central – Southern regions. From direct measurement and interpolation results, the data set of 136 static anthropometric indicators, 50 indicators of joints and arms’ maximum range of movement on 9 horizontal planes were divided by gender into 5 age groups and 3 surveyed regions have been completed and used as a basis for compiling the draft of Static and dynamic Atlas of the Vietnamese in working age of the period 2017 - 2019.
- Based on the research results of the project, researchers of VNNIOSH compiled the draft of “The Atlas of static and dynamic anthropometric and ergonomics for Vietnamese people in the working age of the period 2017 - 2019” consisting of 6 chapters, classified by men and women into 5 age groups. In the draft Atlas, the first 2 chapters will present the research method, some comments on the physical stature of the Vietnamese in the current period; The next 03 chapters provide static anthropometric data, data of the range of movement of Vietnamese people’s arms and joints in the period of 2017-2019; The final chapter (Chapter 6) presents some principles for the use of anthropometric data when designing production equipment and workplaces.
References
[1]. NILP (1986). Atlas of anthropology for Vietnamese in working age - static anthropometric data, Science and Technics Publishing House.
[2]. NILP (1991). Atlas of anthropology for Vietnamese in working age - dynamic anthropometric data on the hands’ range of movement, Science and Technics Publishing House.
[3]. NILP (1997). Atlas of anthropology for Vietnamese in working age - dynamic anthropometric data on the joints’ range of movement, Science and Technics Publishing House.
PhD. Ngan Pham, MA. Hien Nguyen
Assoc Prof.Doc. Hong Nguyen et al
(Source: Vnniosh.vn)