Studies on the growth characteristics of rural Koreans : with special reference to the residents of Honam rural area
It is generally accepted that physical growth is influenced not only by biological factors of the individual, but also by such internal and external factors as heredity, diseases and environmental conditions, i.e., nutrition, sanitation, geographical differences, climate and seasonal changes, occupation, socio-economic conditions, mental and physical exercises.
Between the urban and rural ways of life, there is a vast difference in environment, culture, economic conditions, traditions and working conditions. it is conceivable that there may exist an appreciable difference in the growth process among the inhabitants in these two areas. This, in fact, has been established in other countries.
Numerous studies have been published on the physical growth of Koreans during the past half century, but, almost all of these materials dealt with the people of the urban areas. Detailed studies on the growth pattern of rural Koreans are scarce and, for this reason, the differences and characteristics of the growing process between these two areas are not known.
The author has been impressed by the unusual growth patterns of the Korean people in the rural area where he lives and this report is based on the study of these growth characteristics among the inhabitants of HONAM area of Cholla Pukdo, Korea.
In determining the standard values of growth, the indirect ad hoc survey method of measuring a large number of inhabitants of different ages is more convenient than direct co hort method of measuring the same individuals periodically over a number of years. The former was used in this study. In order to avoid intricate samplings of various areas of the entire country and to study specific features of growth processes of rural people who are fairly homogenous in their ways of life, the HONAM District which satisfied these conditions was selected. This study was
carried out between May, 1953 and November, 1955. The number of persons studied were; male, 11, 113, female, 8, 244, or a total of 19,357 and their ages ranged from birth to 20 years. Biometrical constants, correlations and nutritional indices were tabulated by body measurements and statistical analyses were made.
Part Ⅰ. The Values of Body Measurements Ten(10) items were selected which were thought to represent most clearly the
progress of growth. These were height, weight, girth of chest, sitting height, girth of head, girth of upper arm, span of arms, girth of waist, anterior-posterior dismeter of chest and transverse diameter of chest. The following data was obtained
in relation to age and sexes:
1. Biometric constants and growth curves.
2. The annual average growth and percentage of increase at various ages.
3. The differences in growth between sexes.
4. The differences in growth between urban and rural Koreans.
A summary of above intems is as follows:
1. The course of growth from birth to maturity can be divided into 5 growth periods. The five(5) periods are:
a. The first or infant period:
From birth to one or two years of age, the period of very rapid growth.
b. The second or preschool age period:
From 2-3 to 5-6 years of age, the first half of the period of steady rate of growth.
c. The third or school age period:
From 6-7 to 10-12 years of age, the second half of the period of steady rate of growth.
d. The fourth or puberty period:
From 11-13 to 15-18 years of age, the second rapid growth period.
e. The fifth or growth completion period:
Growth completion period subsequent to puberty.
2. The annual average growth and percentage of increase at various ages are the greatest at the first period, the slowest at the second and third period, the second rapid increase at the fourth, and finally the completion of increase at the fifth period.
3. There is evidence to suggest that the growth rate of the children born just before or at the end of Second World War was slower than that of the children born in other years.
4. The arithmetic means of all items of measurements are generally greater in made than in female; but puberty growth comes one to three years earlier in female than in male. The bright, weight, sitting height, girth of upper arm, span of arms,
girth of waist and transverse diameter of chest of the females during the puberty period temporally exceed those of the male and, consequently, the growth curves of both sexes cross each other in this period. The curves of measurements of the girth
of chest, girth of head and anterior-posterior diameter of chest did not cross each other but became closer during puberty.
5. In general, there was little difference in the growth rates between the inhabitants of urban and rural areas during infancy and the period of growth completion. The rural people, however, showed poorer growth during preschool and school age periods and poorest growth rates during the puberty periods. The onset of puberty growth comes one to two years later in rural people as compared to the residents of urban areas. Since 96% of the babies were breast fed in this survey, the growth rate during the first infant period seemed fairly satisfactory, but a number of factors, such as the lack of adequate weaning care, nutritional
deficiencies, poor housing, lack of environment sanitation, traditions etc., were thought responsible for the slower growth rates from preschool age to puberty among the rural people.
6. Comparison of the measurements of the height, weight, girth of chest and sitting height in this survey with those of the Japanese, reveals that the rural Koreans have slow growth rates during the school age and puberty periods, but faster growth rates in the remaining growth periods. The Japanese had poorer growth rates than the Koreans throughout the whole growth periods before World War Ⅱ. It should be noted, however, that they showed a better growth pattern during the school age and th age of puberty since the War.
Part Ⅱ. Correlation
A. Coefficient of Correlation
Each part of the body maintains a close relationship and balance between each other. In evaluating the level of physical development, it is therefore, difficult to judge the relationship from the values of body measurement of each separate items alone. To indicate and clarify the relationship between defferent
parts of the human body, the coefficient of the correlation is the simplest and the most convenient way.
In this study, coefficient of correlation was computed by ages and sexes between 5 items of body measurement; namely hight, weight, girth of chest, sitting height and girth of upper arm which indicate most closely the site of nutrition. The number of persons tabulated are male 6,897; female 4,993 or a total of 11,890 ranging from birth to 20 years in age.
1. There are no trends of increase or decrease of coefficient by age throughout the whole growth periods.
2. In general, unstabilizing correlation was seen in the first and second periods and stabilizing correlation after the third periods.
3. The means of coefficient of each item which was computed by Z conversion, do not show significant difference between sexes, except the coefficient of correlation between sexes, except the coefficient of correlation between the weight and girth of upper arm. The degree of correlation is as follow :
a. Items which show a high degree of positive correlation : Hight and weight : height and sitting height : weight and sitting height : weight and girth of chest for both sexes respectively : weight and girth of upper arm for the female.
b. Items which show a moderate degree of Positive correlation : height and girth of chest : height and girth of upper arm : girth of chest and girth of upper arm, girth of chest and sitting height for both sexes and weight and girth of upper arm for the male.
c. Items which show a low degree of positive correlation : girth of upper arm and sitting height. In general, it was shown that a high degree of positive correlation existed in regard to weight, and a moderate or low degree of positive correlation with the combinations of hengths and circumferences.
B. The Arithmetic Mean of Body Measurements in Relation to Height, Ages and Sexes.
The expression of weight, girth of chest, sitting height, and girth of upper arm in relation to height is a useful practice which is widely used to evaluate the physical growth of human body. The author has made an attempt to compile tables of
the above items which can be used to judge the physical growth rates of the people in this area. The number of persons tabulated are male 10,590 ;female 7,745 or a total of 18,335 ranging from birth to 20 years in age.
The summary of the measurements in relation to height are as follows :
1. The arithmetic mean by age an height increase in proportion to age and height.
2. The arithmetic mean by age and height for girth of chest are greater in male than in female throughout whole growth periods, and for weight, sitting height and girth of upper arm, males predominate over females before puberty but the reverse is true after this period.
Prat Ⅲ. Physical and Nutritlonal Indices
The means of height, weight, girth of chest, sitting height and girth of upper arm themselves are good indications by themselves in evaluation the morpholoical features, processes of growth and developments of the human body. Since the human body consists of various morphological factors, the evaluation of the untritional
conditions from the measurement of a single factor is liable to lack university. It is, therefore, necessary to show physical and nutritional conditions by objective values, thai is, indices which are calculated by combinations of body measurements.
The author has selected and computed 15 varieties of indices which were constructed from combinations of the above 5 items.
The indices are : Relative weight, Rohterm, Kaup, Wellisch, Relative girth of chest, Bornhardt, Vervaeck, Relative sitting height, Porquet, Oppenheimer (AB/L, A/B), Mahillon, Broca, Pignet and Messerli.
A summary of the above items computed indicates the following :
1. Each index has its own distinctive feature. It can, however, be devided into four groups of indices according to increments of age :
a. Indica which have trends of increase : Relative weight, Wellisch.
b. Indices which has a trend of decrease : Bornhardt.
c. Indices which has trend of decrease after the initial increase : Pignet.
d. Indices which has trends of parallelism of increase after initial decrease :
Rohrer, Kaup, Relative girth of chest, Vervaeck, Relative sitting height, Proquet, Oppenheimer (AB/L, A/B), Mahillon, Broca and Messerli.
2. The nutritional conditions of the children who were conceived or born just before or at the end of Second World War were inferior compared with those of the children born in other years. These items were : Relative weight, Rohrer, Kaup,
Wellisch, Relative girth of chest, Bornhardt, Vervaeck and Oppenheimer (AB/L, A/B/).
3. It is difficult to find the best index since all of the indices computed indicate moderate degree of fluctuation. It is, therefore, necessary to make some corrections if they are to be utilized as physical and untritional indices.
4. Comparing the findings of this survey with the those of the urban people, the only difference was seen in the relative girth of chest which was greater in rural inhabitants than in urban residents throughout the entire growth periods. In other
items, little difference was seen between urban and rural persons throughout the growth periods. Comparison of this data with the results of body measurements in
Part Ⅰ. show that the same growth tendencies are seen during infancy and in the fourth periods, but no marked differences were noted in the second and the third periods.
5. The indices can be used as an auxiliary measurement for evaluation of physical and nutritional conditions.