Objective: To accumulate the information in the long-term studies of the variation of the limb segments length and proportion in the process of growth and development of children, we have measured and summarized the average level of limb segments length for the children and adolescents in the main urban area of Chongqing, calculated the ratios of limb segments length to height and extremities-trunk ratio, body proportions, and analyze their age trends.
Methods: Using cluster sampling, sampling 4715 students of five schools aged 617 years in the main urban area of Chongqing, we measured their standing height, sitting height, arm span, forearm length, upper arm length and lower leg length, calculated their average level and ratios, and observed their age trends.
Results: The study obtained the average levels of limb segments lengths, they show similar growth trend to height, and no significantly gender differences were found before the age of 13. The correlation analysis showed that sitting height, forearm length, upper arm length, arm span and lower leg length are highly correlated with standing height, the correlation coefficient r is all above 0.9 (P<0.05). With the growth of age, the ratios of forearm length, upper arm length, arm span, lower leg length to standing height increased, while the forearm length/upper arm length showed a downward trend (P<0.05). Sitting height/leg length rebounded slightly after the first gradual decline trend with age, gender difference was not obvious before the age of 11, while males smaller than females after 11-year-old (P<0.05), extremities-trunk ratio showed opposite trend.
Conclusions: Sitting height, arm span, forearm length, upper arm length, lower leg length and their ratio to standing height present regular changes with the growth of age, and limb segments length is highly correlated with height.
18 Sep 2014 - 20 Sep 2014