여자 스포츠선수와 초경지연과의 관련성 검토

藤井勝紀(Katsunori Fujii),正美智子(Michiko Sho),추丸武臣(Takeomi Akimaru),김준동(Jun Dong Kim) 한국발육발달학회 2009 한국발육발달학회지 Vol.17 No.4

This review examines the background for studies on menarche and describes the history of studies on delayed menarche with regard to a structural outline for the demonstration of delayed menarche in female athletes. Then, to confirm delayed menarche, it first clarifies what a real delay in menarche is and establishes criteria for what the delay is measured against. In setting these criteria, the effectiveness of deriving the age at maximum peak velocity (MPV) of height with the wavelet interpolation method is discussed. It is shown that delayed menarche in athletes can be demonstrated from the interval between age at MPV of height and age at menarche. Delayed menarche was first demonstrated from mean values in groups, but could not be derived for individuals. A regression analysis of age at menarche against age at MPV of height was then conducted. The validity of the order of the polynomial in the regression analysis was investigated, and from the results the first order regression polynomial was applied. A first order regression polynomial was then constructed and applied to athletes to analyze delayed menarche in individuals. Delayed menarche in athletes was shown. This structural outline for the demonstration of delayed menarche is discussed, but menstrual status after delayed menarche could not be analyzed and remains an issue for the future.

민족 간 신장 차이와 Bergmann법칙의 적용 가능성

藤井勝紀(Fujii, Katsunori),김준동(Kim, Jun-Dong) 한국체육과학회 2021 한국체육과학회지 Vol.30 No.4

Bergmann’s rule(Bergmann, 1847)states that homeothermic animals that live in colder regions such as Northern Europe have larger body sizes with smaller surface area in proportion to body weight in order to minimize heat dissipation. Conversely, in tropical regions body surface area is larger to maximize heat dissipation. For this, shorter heights are advantageous. As to whether this rule applies to humans, surveys of peoples living in cold and tropical regions of the world show that heights tend to be taller in the north and shorter in the south, but simplistic application of Bergmann’s rule cannot always be done in recent years. This is from the effect on physical development of socioeconomic growth in recent years. In the Netherlands, for example, Bergmann’s rule does not apply to height. If one looks only at recent years in this way, a human environmental bias from socioeconomic development is seen and so judgments cannot be made with height alone in each country of Europe today. This human environmental bias can be eliminated applying the secular trend standardization chart for height proposed in this study. Judging the changes in height over the span of about 120 years from 1860 to 1980 with this method allows for evaluation of the height trends in countries located in Northern, Central, and Southern Europe. Heights can then be conveniently explained with Bergmann’s rule. Of course, scientific verification of Bergmann’s rule remains a task for the future.

아동ㆍ청소년기 신체적 발육ㆍ발달곡선에 관한 분석

藤井勝紀(Fujii, Katsunori),田中望(Tanaka, Nozomi),김준동(Kim, Jun-Dong) 한국체육과학회 2012 한국체육과학회지 Vol.21 No.1

In the present study, annual change of physical growth and development was examined during school age. The wavelet interpolation method was applied to cross-sectional data from 6 to 17 years in 2000 and 2005, based on the records of the physique (height, weight, sitting height, leg length), physical strength and motor ability (grip strength, side step, trunk bending, sit-up, 50m dash, standing long jump and handball throwing) announced by Ministry of Education, Science and Technology every year. As the results, the growth distance and velocity curves were analyzed in the physique. In physical strength and motor ability, the developmental distance and velocity curves were also analyzed, and the change of physical strength and motor ability with age was examined. With judging from the growth velocity curve of physique, the growth velocities in leg length was the fastest among the physique in both 2000 and 2005. Moreover, the age at MPV of leg length was also the earliest, and that of BMI was the latest in both 2000 and 2005. It was shown that MPV of grip strength appeared almost in a simultaneous period with MPV of height, and trunk bending and sit-up appeared after MPV of height.

동 아시아민족 발육에 관한 年次推移의 검증

藤井勝紀(Katsunori Fujii),김준동(Kim Jun-dong),노호성(Nho Ho-Sung) 한국체육과학회 2011 한국체육과학회지 Vol.20 No.1

This study attempted to be made to demonstrate the changes in morphological growth in two recent periods of the East Asia ethnic groups, by comparing the morphological growth in adolescence of Japanese, Korean, Han Chinese and Mongols groups in the years 1985 and 1989, and 2004 and 2005. This study applied the wavelet interpolation method proposed by Fujii, and specified the age of maximum peak velocity (MPV) in growth during puberty from the height and weight growth velocity curve. Then, based on age at MPV and annual changes in MPV, early maturation in height growth and time changes in the velocity curve in the East Asia ethnic groups was demonstrated. The results did not reveal any marked changes in the growth of Japanese and Korean boys and girls between these two periods. However, a tendency for earlier age at MPV was seen in both boys and girls in Han and Mongol Chinese. This tendency was particularly marked in Mongols, and maturity was clearly earlier. The trend in these recent 20 years from 1985 to 2005 in Inner Mongolia is thought to be similar to the past phenomenon of earlier maturation in Japanese that was clearly earlier. The trend in these recent 20 years from 1985 to 2005 in Inner Mongolia is thought to be similar to the past phenomenon of earlier maturation in Japanese that was influenced by high socioeconomic development. The factors for the change seen in Mongols are assumed to be considerable improvements in recent years in the dietary habits and environment of Mongols in the Inner Mongolia Autonomous Region of China, and improvements in their social and economic environment.

쌍생아 여아의 유사성 평가 차트의 확립

藤井勝紀(Fujii, Katsunori),김준동(Kim, Jun-Dong) 한국체육과학회 2017 한국체육과학회지 Vol.26 No.4

Twin studies have important implications for verifying the involvement of various genetic and environmental factors in human characteristics. Among these twin studies, many statistical analyses of the similarities of monozygotic and dizygotic twins require twin pair data. To analyze the similarities of growth process in pair data for twin pairs, Fujii described the growth curve with the wavelet interpolation model and proposed a method of analyzing the similarities between the described growth curves based on cross-correlation functions. In this study, an assessment criteria chart was constructed to evaluate the similarities between girls’ monozygotic and dizygotic twins by applying wavelet interpolation model to these growth curve descriptions and cross-correlation functions. Height growth data for random pairs of general girls were taken and the growth processes were described with the wavelet interpolation method. Cross-correlation functions were then applied to the growth velocity curves of the described random pairs. An evaluation chart of similarities was built from the derived cross-correlation functions, and in the cross-correlation functions from those evaluation charts, r ≧ 0.94 was found to be the standard criterion showing the level of similarity. When the cross-correlation functions of height growth of monozygotic and dizygotic twins were applied to these charts, the correlation of monozygotic twins was high and that of dizygotic twins was somewhat high. Thus, the similarity of monozygotic twins was seen to be high.

유유아 신체발달의 시대적 변동을 제어하는 고도 경제 성장의 요인 분석

藤井勝紀(Fujii, Katsunori),可兒勇樹(Kani, Yuki),糟谷浩輔(Kasuya, Kosuke),김준동(Kim, Jun-Dong) 한국체육과학회 2017 한국체육과학회지 Vol.26 No.5

The Ministry of Health, Labor and Welfare has published measurement records on height, weight, chest circumference, and head circumference in 0 to 6 year-old children from 1960 to 2010 as indicators of physical development in early childhood in Japan. Physical development evaluation charts have been developed from these records using percentile methods, but reports on the trends in physical development over time are limited. This is because no method has been established to scientifically analyze physical growth. Even more difficult is investigating secular trends in physical growth and linking those trends to economic growth. In this study, we identified the first largest peak velocity (FLPV) during the year after birth in infant physical growth records (height, weight, chest circumference, head circumference), and applied the wavelet interpolation model to the variations over time in the identified FLPV. Next, we applied the wavelet interpolation model to the secular variations in GDP for the same years. We then applied a cross correlation function to the relationship between the curves of FLPV and GDP variations over time, and investigated how high economic growth acts as a controlling factor variations in physical development of young children over time. The speed of variation in the physical development of children over time was the greatest around 1980. By synchronizing GDP to that time, the results suggest that high economic growth is a controlling factor in the physical development of young children.

후쿠시마 원전사고가 학령기 아동의 신체조성에 미치는 영향

藤井勝紀(Fujii, Katsunori),渡部琢也(Watanabe, Takuya),田中 望(Tanaka, Nozomi),김준동(Kim, Jun-Dong) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.2

Earthquake disasters have a significant impact on the tendency for obesity. Body fat readily increases because physical activity is restricted. The Fukushima nuclear power plant disaster in the Great East Japan Earthquake that occurred several years ago was probably not an exception. However, no detailed examinations of the effects on body composition have yet been reported. One reason for the lack of findings verifying the detailed effects on people’s bodies, even though six years have passed since the disaster, is that no method of verification has been clearly established. In this study, by analyzing the age-related changes to body composition scientifically, we attempted to verify the effects of earthquake disasters from a comparison with normal age-related changes. The subjects were boys and girls from an elementary school in the region affected by the nuclear disaster in Fukushima Prefecture. Their body composition was measured and height, weight, BMI, body fat percentage, and muscle percentage were calculated. A wavelet interpolation model was applied to the cross-sectional age-related changes in BMI, body fat percentage, and muscle percentage in first to sixth grade elementary school students. As a control group, the wavelet interpolation model was applied in the same way to the age-related changes in body composition of elementary school students in an area completely unaffected by the earthquake disaster. The age-related changes in body composition of the elementary school students in the two areas were compared. The results showed that in the age-related changes in body fat percentage and muscle percentage, the Fukushima schoolchildren tended to have a higher body fat percentage and lower muscle percentage. There was also a slight difference between the two areas in the emergence of the local peak velocity in the age-related changes. However, it is difficult to determine the effects of the nuclear power plant disaster from the present results alone. They may be further clarified in the future by deriving the results up through junior high school.

연령증가에 따른 유아 골밀도의 평가차트 구축

藤井勝紀(Fujii, Katsunori),可兒勇樹(Kani, Yuki),糟谷浩輔(Kasuya, Kosuke),김준동(Kim, Jun-Dong) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.2

A clear method for evaluating bone density findings in young children has not been established. One reason behind this is that the changes with age in bone density during early childhood have not been clarified. In this study, a mixed cohort method was adopted and a least squares approximation polynomial was applied to bone density indices (stiffness, BUA, SOS) of children from 3 to 5 years old. We then attempted to construct a bone density evaluation chart for early childhood by clarifying the changes in bone density with age. The method was to measure bone density in 3, 4, and 5 year-old children, and then analyze the age-related changes in the bone density index data obtained in a mixed cohort. The results showed changes with age in the values for stiffness and SOS. The optimal polynomial obtained with least squares approximation was shown to be a third order polynomial for boys and a fourth order polynomial for girls. Therefore, in the standard regression evaluation chart for stiffness values a third order polynomial was applied for boys and a fourth order polynomial was applied for girls. An evaluation chart was constructed from a 5-grade regression evaluation. Normalization was then seen in the frequency distribution, and the bone density evaluation constructed in this study for young children was seen to be effective. The mixed cohort in this study did not provide fundamentally simple cross-sectional data but rather semi-longitudinal data that included almost all tracking data from the same subjects. Therefore, clarification of the trends in changes with age in stiffness has great significance.

골밀도 연령증가변화구도에 기초한 Peak Stiffness의 검증

藤井勝紀(Fujii, Katsunori),田中望(Tanaka, Nozomi),고인태(Ko, In-Tae),김준동(Kim, Jun-Dong) 한국체육과학회 2015 한국체육과학회지 Vol.24 No.6

Bone mass is reported to peak at about the age of 15 to 17 years, but the peak in bone density is not clear. Therefore, the pubertal peak in bone density is also unknown. In this study, using a method of assessing bone density by stiffness coefficient, we applied a least squares approximation polynomial to stiffness coefficient age distance values from the first grade of elementary school until the third year of junior high school (ninth grade), and investigated the changing trends with age. The results showed the age-related changes in the stiffness coefficient, BUA value, and SOS value based on third order least squares approximation polynomials. The peaks determined from the second-order polynomial curve of the first derivative were 11.4 years old with the stiffness coefficient and near 11.5 years old with the BUA and SOS values. Next, to identify the pubertal peak (maximum peak velocity: MPV) of the stiffness coefficient, wavelet interpolation was applied and peak stiffness was derived. The MPV age of the stiffness coefficient was 11.2 years old. The MPV age of height is 12.6 years old and the MPV of weight is 13.4 years old. This MPV age for bone density is earlier that the MPV ages for height and weight, and it is conjectured that on average this is related to the growth of the length of the lower limbs (lower legs). On the other hand, the possibility cannot be ruled out that substantial development of bone density promotes growth in height.

일본여성의 지역적 차이에 의한 초경지연의 발육학적 검증

藤井勝紀(Katsunori FUJII),노호성(Noh Ho-sung) 한국체육과학회 2009 한국체육과학회지 Vol.18 No.2

To elucidate delayed menarche in female athletes, Fujii established a system to evaluate delayed menarche by deriving the delay in menarche from the interval between age at MPV of height and age at menarche, while at the same time establishing judgments from regression evaluations of age at menarche against age at MPV of height. In this study, the system Fujii developed to evaluate delays in menarche was applied to the age at menarche of girls in the Tokai and Hokuriki regions of Japan, and we then investigated regional differences in delays in menarche between these two regions. The girls were 209 girls from the Tokai region and 96 girls from the Hokuriku region who underwent almost no sports training around the time of menarche. Longitudinal growth data on the girls’ height were obtained from health records from the first year of elementary school until the final (third) year of high school. The age at menarche was obtained from a questionnaire survey of the 209 girls in the Tokai region and 96 girls in the Hokuriku region. The delayed menarche evaluation system was applied to the age at menarche of girls from the Tokai and Hokuriku regions, and the average delay in menarche in the Hokuriku region was estimated from the interval between age at MPV of height and age at menarche. Regression evaluation of age at menarche against age at MPV of height was used to clarify the delay in menarche for individual girls in the Hokuriku region. It was shown that the proportion of girls with delayed menarche was significantly higher in the Hokuriku region than in the Tokai region. This was inferred to be from the effect of stress from living conditions that results from the characteristic climate of the Hokuriku region.