چكيده لاتين :
Background and aims: The structural characteristics of the human body are influenced by factors such
as race, age, gender and type of nutrition, and vary in different nations. Several studies have shown that
anthropometric data varies in different societies. It is important to note that despite the high accuracy and
low cost of direct measurements of anthropometric dimensions and the existence of extensive databases
about them in different societies, there are still numerous problems in direct measurements of
anthropometric dimensions of individuals, some of which include: the need to train individuals before
measuring the dimensions that are time consuming and with their specific problems, interference in the
activities of individuals and, consequently, the possibility of lack of proper collaboration in measuring
the dimensions, requires the measurement of dimensions by the homosexual person, especially in
Islamic countries, due to the cultural and ethical issues of those societies, and the discontent of most
people, especially when it comes to repeat the measurements. Therefore, the role of the use of indirect
methods, including the use of biometric regression relations, is more important for estimating the
anthropometric dimensions of the target community. The advantages and limitations for each of the
commonly used anthropometric measurements and the particular conditions of real working
environments have led to the need for a fast, convenient, acceptable, and non-interfering procedure for
workers to determine the anthropometric dimensions necessary. In this regard, attention to the biometric
relationships of physical dimensions can be useful. Because in the case of finding a meaningful
relationship between one or more anthropometric dimensions with other physical dimensions, it is
possible to provide the anthropometric characteristics with a high degree of certainty by little time and
cost and without the need for specialty. Therefore, this study aims to investigate and determine the ratio
of some of the anthropometric dimensions of the indicator, which is used in various designs used by
ergonomics and industrial designers, in sitting and standing static situations and in two groups of
students in the age group of 18 to 26 years old.
Methods: Demographic data were first collected through questionnaires. The dimensions of the study
included 20 positions in standing position and 18 dimensions in sitting position. Anthropometric
measurements were done using caliper, tape measure, balance and checkerboard sheet (Anthropometer).
To increase the assurance of measurements, multiple dimensions were selected randomly and measured
by two people. The results of this study were analyzed using correlation coefficient test and if there were
no significant differences between measurements by different individuals, the study continued until the
end. Otherwise, training was needed for the correct examination method to be uniformed and
measurements are repeated. 206 people, including 162 women and 44 men, were enrolled in this study.
Sample subjects were selected randomly and clustered among male and female students. According to
the main goal of the study, people with severe abnormal BMI, people with a history of musculoskeletal
disorders or congenital disorders, people with severe diets, pregnant women and athletes were excluded.
In order to increase the accuracy of measurements, all measurements were made in standing and sitting
conditions, in a non-shoe mode and with a minimum of clothing (underwear). Also, in order to avoid
interference with the measurement of some physical dimensions due to lunch, the time of measurements
was selected between 8:00 and 12:00. The accuracy of the measurements was considered to be 0.1 cm in
all dimensions. The results of the study were analyzed using SPSS 22 software. In this study, the distribution of anthropometric data was performed using dispersion indices and percentiles 5, 50 and 95,
as well as mean and standard deviation. Also, to investigate the biometric relationships of different
dimensions in relation to the height dimension of individuals in the population, multiple regression
models were used. In these models, the biometric relationship of various dimensions of the body based
on height dimension, which was easily measured, was examined in static sitting and standing positions.
Results: The results of demographic information analysis of the subjects were studied in two groups of
gender and in the age range of 18 to 26 years old. Also, the 5th, 50th and 95th percentiles and standard
deviations of measured dimensions in standing and sitting subjects and gender were presented,
respectively. In general, 12 regression equations were obtained for standing dimensions relative to height
in women and 14 regression equations for standing dimensions relative to height in men. The
corresponding values for sitting dimensions were 14 and 12 for men and women, respectively. In
accordance with the main objective of the study which was finding relationships between the
anthropometric dimensions of individuals in static states to estimate and predict other anthropometric
dimensions of a person, the findings of this study showed that the mean and standard deviation of most
anthropometric data in women and men have a significant difference with each other (P <0.05), and in
general, its values in women were smaller than males. Also, comparison of 5, 50 and 95 percentiles in
standing and sitting anthropometric dimensions showed that there was a significant difference between
static anthropometric dimensions in standing and sitting position in both gender groups. So that the
standing dimensions in men were more than women in all three percentiles. However, in the dimensions
of sitting, the amount of this difference is reduced and in some cases, such as head length, depth of chest,
and abdominal depth, there is no significant difference in the 5, 50 and 95 percentiles of men and women
were seen. The findings of the existing regression relations between the different static standing
anthropometric dimensions and the selected index in this study, which was the height of the subjects,
also showed that there is not a significant correlation between height and anthropometric dimensions of
the width of the hand, the internal and external distance between the two eyes and the width of the wrist
in women. In the 95% confidence interval among women, standing grip reach, length of upper limb and
elbow height with correlation coefficients of 0.791, 0.742 and 0.737 have shown the highest fit with
height dimension and other dimensions have shown moderate and weak correlations with dimensional
dimensions. In men, the shoulder height, eye height and length of upper limb showed the highest
relationship with height with correlation coefficient of 0.949, 0.867 and 0.840, respectively.
The relationships between different dimensions of body and height of people in this study and the
appropriate and acceptable correlation coefficients obtained between the many dimensions such as eye
height, shoulder height, elbow height, knuckle height, upper limb length, shoulder-grip length, standing
grip and buttock knee length, with the height of the individuals, can be indicative of the fact that
acceptable estimates of the dimensions can be obtained by measuring only the height of people. From
the total of 38 anthropometric dimensions studied in this study (20 standing and 18 sitting positions), 26
regression relations were statistically significant (P <0.05) at 95% confidence interval for both men and
women groups, separately. Although the relationships were statistically significant, they did not include
the same dimensions in the two gender groups. For example, in women, sitting height and sitting
shoulder height were significant and had a regression relation, but in men, no significant relationship
was found between these dimensions.
Conclusion: Due to the limitations of anthropometric measurements during design, the use of biometric
relationships can be proposed as a practical, rapid, and acceptable alternative of indirect methods. Based
on the results of this study as well as other similar studies, it can be seen that stature can be considered
as a suitable indicator and predictor dimension in designs that require specific body dimensions such as
shoulder height, eye height, standing grip, upper limb length and elbow height. However, given that the
study was conducted in a small student population, and it was not possible to select the same number of
people from two groups of gender, it is suggested that, in order to increase the accuracy of the work and
the reliability of the results, the complementary and targeted studies should be developed and
implemented in the following the present study. So, it is expected that the anthropometric predictive
tools such as a predictive software can be obtained so that, by measuring the minimum dimensions of
each person as inputs, other dimensions required for design would be estimated, reasonably. Also,
although examination of a large number of sitting and standing positions in this study compared to other
studies has been considered as one of the strengths of the present study, it is recommended that in later
studies, in addition to the relationship between dimensions measured and stature, relationships between
stature and other anthropometric dimensions, which can easily be measured, is to be considered.
