ABSTRACT
OBJECTIVE@#To analyze the characteristics of the age at peak height velocity and peak height velocity of primary and middle school students in Zhongshan City, Guangdong Province, and to explore the law of the sudden increase in adolescent height in this area, and to understand the law of height growth spurt in adolescence by longitudinal tracking of the height of children and adolescents in Zhong-shan City.@*METHODS@#Based on the physical examination database of primary and middle school students in Zhongshan City, Guangdong Province from 2005 to 2016, individuals who had been continuously tracked for more than 6 times were selected as research samples. SITAR model was used to fit the height data of the sample population, and the age at peak height velocity and peak height velocity were calcula-ted.@*RESULTS@#A total of 49 579 subjects were included in this study, including 26 524 boys and 26 008 urban students. The median follow-up ages of boys and girls were 7.74 and 7.72 years, respectively. The boy's height spurt peak age was (12.72±0.89) years, and later than the girls at the age of (10.98±0.95) years (t=207.639, P < 0.001), the boy's height spurt peak velocity of (10.12±1.49) cm/year, higher than the girls of (8.35±1.12) cm/year (t=150.826, P < 0.001). The gender differences of height spurt peak age and height spurt peak speed in urban and rural students were consistent with the whole sample. The height surge peak age of urban male students was earlier than that of rural male students, and the height surge peak speed of urban female students was lower than that of rural female students.@*CONCLUSION@#The peak age of the surge of girls was earlier than that of boys, but the peak rate of the surge of girls was lower than that of boys, the peak age of urban students was earlier than that of rural students, but the peak rate of urban boys was lower than that of rural boys in Guangdong Province.
Subject(s)
Adolescent , Child , Female , Humans , Male , Body Height , Rural Population , Sex Factors , StudentsABSTRACT
O objetivo do estudo foi investigar a relação entre maturação biológica, modulação parassimpática da frequência cardíaca e teste de resistência intermitente em jovens jogadores de futebol. Participaram do estudo 23 jovens futebolistas (15,3 ± 1,1 anos, 175 ± 6 cm, 64 ± 7 kg) das categorias sub15 e sub17 de uma equipe da 1ª divisão do campeonato paulista. O estado maturacional foi determinado pela idade do pico de velocidade de crescimento (PVC), usado como indicador relativo de maturidade somática calculada através das medidas de estatura, altura tronco-cefálica, comprimento das pernas, massa corporal e as dobras cutâneas. As medidas de variabilidade da frequência cardíaca (VFC) foram obtidas em repouso durante 5 minutos e, posteriormente, analisadas pela variável raiz quadrada da média dos quadrados das diferenças entre intervalos RR normais adjacentes (rMSSD). Os indivíduos realizaram o teste de resistência intermitente, Yoyo intermittent recovery test level 2 (YIRT 2), após as medidas de VFC terem sido obtidas. Os resultados do presente estudo mostram que não há relação entre modulação parassimpática da frequência cardíaca (rMSSD = 57,4 ± 26,4 ms) e o estado de maturação biológica (0,67 ± 0,81 anos) dos jovens futebolistas (r= 0,30; p=0,163), enquanto que o teste de resistência intermitente (YIRT 2= 658 ± 151 m) possui uma grande correlação com o pico de velocidade de crescimento (r= 0,71; p< 0,001). A modulação parassimpática da frequência cardíaca possui grande correlação com o teste de resistência intermitente dos jogadores (r= 0,54; p= 0,007). Conclui-se que a utilização da idade do PVC e da VFC como indicador de desempenho no YIRT2 em jovens futebolistas....(AU)
The aim of the study was to investigate the relationship between biological maturation, parasympathetic heart rate modulation and intermittent endurance test in young soccer players. Participated of the study 23 young soccer players (15.3 ± 1.1 years, 175 ± 6 cm, 64 ± 7 kg) of the sub15 and sub17 categories of the team from the 1st division championship Paulista. The maturational status was determined by the age of the peak height velocity (PHV), used as relative indicator of somatic maturity and are calculated trhough measures of height, trunk-cephalic height, leg length, body weight, and skinfolds. The Heart rate variability (HRV) measures were obtained in rest during 5 minutes and, posteriorly, analyzed by the variable root mean square of the successive difference (rMSSD). For the intermittent endurance test the subjects performed the Yoyo intermittent recovery test level 2 (YIRT 2), before the HRV measures has been taken. The results of the present study shown which there was not relationship between parasympathetic heart rate modulation (rMSSD = 57,4 ± 26,4 ms) and status biological maturation (0,67 ± 0,81 years) of the young soccer players (r= 0,30; p=0,163), then that the intermittent endurance test (YIRT 2= 658 ± 151 m) has a great correlation with PHV (r= 0,71; p< 0,001). The parasympathetic heart rate modulation has a great correlation with intermittent endurance test of the players (r= 0,54; p= 0,007). In this way, the use of the PHV age and HRV as indicator of performance in YIRT2 in young soccer players is suggested....(AU)
Subject(s)
Humans , Male , Adolescent , Physical Education and Training , Soccer , Heart RateABSTRACT
This study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of the patients with skeletal class II division 1 or division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group (79 for pre-peak, 40 for peak, 40 for post-peak). Total 159 lateral cephalograms (70 for skeletal class I, 51 for skeletal class II, division 1, and 38 for skeletal class II, division 2) were selected.The growth of anteroposterior dimension of the pharyngeal airway were statistically significant among growth periods. The dimension for the nasopharyngeal and oropharyngeal airway space was the smallest in the division 1 skeletal class II group followed by class II division 2 and skeletal class I.
Subject(s)
Adolescent , HumansABSTRACT
Objective To discuss characteristics of height growth such as Peak Height Velocity (PHV) and Age at Peak Height Velocity (PHA) during adolescence,and to compare the results with other research findings.Methods Primary and middle school students' annual physical examination data of Zhongshan in 2005-2010 was used.The height velocity by age,PHV,PHA,height velocity by PHA were calculated.Results The average peak height velocity boys was ( 10.03 ± 1.67 ) cm/yr.and that of the girls was ( 8.39 ± 1.05 ) cm/yr.Both findings were close to the results from previous similar findings.The average age at which peak height velocity reached 12.28± 1.30 years for boys and 10.78 ± 1.04 years for girls,both lower than the previous findings.The correlation coefficients,between height level and PHA were -0.357 (P＜0.001) for boys and -0.338 (P＜0.001) for girls.Conclusion The height levels were positively related to the height velocity before PHA.The Zhongshan students' PHA was lower than the Beijing,Shanghai and Shenyang students,also lower than American and Britain students',but their PHVs were similar.
ABSTRACT
OBJECTIVE: This study investigated the onset, peak height velocity (PHV) and end of adolescent growth spurt as well as menarcheal timing deduced from surveying accumulative height growth over many years. METHODS: Ninety six students of Samgoe high school between 1st and 3rd grade that were in good health participated in the research. A survey questionnaire was distributed to examine the students' health status and menarche timing. RESULTS: Adolescent growth spurt typically began at the age of 9.9 and reached a PHV at the age of 11.6. The growth spurt ended at the age of 14.1 on average. The average age of menarche was 12.6 years, which was about one year after the PHV of adolescent growth spurt. In most cases, menarche came after PHV. But in 24% of the students, menarche and PHV was nearly coincident or menarche preceded PHV. The growth curves were classified into four types. A typical adolescent growth spurt showed one PHV on graph that drastically drops after the PHV. However, there were cases with two PHVs. CONCLUSIONS: The results indicate that individual growth patterns show large individual differences, however the categorization into the various growth curves may aid in predicting individual growth patterns.