Secular trends for takeoff and maximum adolescent growth for eight decades of Japanese cohort data

Ali, M. A.; Lestrel, Pete E.; Ohtsuki, Fumio

doi:10.1002/1520-6300(200009/10)12:5<702::aid-ajhb15>3.0.co;2-w

Cited by 27 publications

(8 citation statements)

References 23 publications

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“…A decline in estimated mean ages at PHV among Danish youth born in the 1930s through the 1960s, 12.5 to 12.0 years in girls and 14.5 to 14.2 years in boys, was recently reported [61]. Ages at PHV did not differ among boys and girls in the Fels Longitudinal Study born in the 1960s, 1970s and 1980s [62], while ages at PHV among Japanese youth born in the 1960s through early 1980s changed negligibly [63,64].…”

Section: Discussionmentioning

confidence: 94%

Tanner–Whitehouse Skeletal Ages in Male Youth Soccer Players: TW2 or TW3?

et al. 2017

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Background. The Tanner-Whitehouse radius-ulna-short bone protocol (TW2 RUS SA) is a widely used indicator of maturity status. The scale for converting ratings to an SA has been revised (TW3 RUS SA) which may have implications for studies of youth athletes.Objectives. To compare TW2 and TW3 RUS SAs in an international sample of youth soccer players and to compare distributions of players by maturity status defined by each SA Methods. SA assessments with the TW RUS method were collated for 1831 soccer players 11-17 years from 8 countries. RUS scores were converted to TW2 and TW3 SAs using the appropriate tables. SAs were compared within chronological age (CA) groups. The difference of SA minus CA with each method was used to classify players as late, average or early maturing. Concordance of maturity classifications with TW2 and TW3 SAs was evaluated with Cohen's Kappa coefficients.Results. For the same RUS score, SAs were systematically and substantially reduced with TW3 compared to TW2; mean differences ranged, on average, from -0.97 to -1.16 years. Kappa coefficients indicated fair concordance of maturity classifications based on TW2 and TW3 SAs.Conclusion. TW3 SAs were systematically lower than corresponding TW2 SAs in youth soccer players. The differences between scales have major implications for the classification of players by maturity status, which is central to many talent development programs.

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Section: Discussionmentioning

confidence: 94%

Tanner–Whitehouse Skeletal Ages in Male Youth Soccer Players: TW2 or TW3?

et al. 2017

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“…Ali et al (2000) studied secular changes in Japanese leg length for birth cohorts from 1943 to 1978, showing a steep rise in leg length as a percentage of height from 1943 to 1968 but a plateau thereafter. In addition they showed that this percentage increased with age until puberty, i.e., 13 years in boys and 11 years in girls, and then either stabilized (girls) or fell slightly (boys).…”

Section: Discussionmentioning

confidence: 99%

“…Thus, the secular trend can be decomposed into three separate components. The technique represents an extension of the approach by Ali, Lestrel, and Ohtsuka (2000) who analyzed growth curves of Japanese height over eight decades using kernel regression, and identified turning points on the curves reflecting age at take‐off and age at peak velocity.…”

Section: Introductionmentioning

confidence: 99%

Fifty years of child height and weight in Japan and South Korea: Contrasting secular trend patterns analyzed by SITAR

Cole

Mori

2017

American J Hum Biol

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Objectives Japanese and South Koreans have traditionally been shorter than Europeans, but have recently become appreciably taller. The aim was to quantify the secular trend patterns in height and weight growth in the two countries over 50 years using the SITAR growth curve model. Methods Data on mean height and weight by sex in 1‐year age groups from 1 to 20 years were obtained by decade in South Korea (1965–2005) and Japan (1950–2010). The data were analyzed using SITAR (SuperImposition by Translation And Rotation), which estimates a mean curve and three adjustments–size, timing and intensity–reflecting how the individual surveys differ from the mean. A sensitivity analysis compared results for the Japanese data based on cohort as well as period. Results Growth patterns in the two countries changed dramatically over the study period, affecting not only height and weight but also developmental age, in that the growth period advanced in timing and shrank in duration. SITAR fitted the data well. The trends were larger in South Korea than Japan, and puberty timing in Japan stabilized by 1970. Most of the height increment seen in adults had already accrued by age 1.5 years, whereas the adult weight increment accrued throughout childhood. Conclusions The secular height trend in these countries represents increased growth in the long bones during infancy, so it can be viewed as the inverse of stunting. There are striking country differences in growth pattern, but they are not easily explained by differences in national income, diet or lifestyle.

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“…We first confirmed the adolescent growth spurt characteristics in Japanese children according to Ali et al .., using data from The Statistical Report of the School Health Survey by the Ministry of Education, Science, Sports and Culture, Japan and then, on the basis of the criteria defined by Aksglaede et al ., we calculated the participants' age at peak height velocity (APHV). We calculated the height velocity from the first grade of elementary school (6–7 years of age) to graduation from junior high school (14–15 years of age); height velocity was defined as the difference in the heights recorded for 2 adjacent years.…”

Section: Methodsmentioning

confidence: 99%