Studies on the Relative Variation of Chest Dimension at 18 Years Old

In this paper, we consider relative variation of some chest dimensions at youth by the analysis of the absolute size values and allometry. Because few reports have ever been published related to this problem.The materials were 18 years old Japanese students and consists of 236 males and 83 females. We took the girth of chest at rest (GCR) on x-axis and the others on y-axis. All subjects were devided into several groups according to their measuring values of GCR, for instance, the 80cm group was composed of the subjects from 80.0 to 80.9 cm of GCR, and similary other groups. And arithmetic means of all items were calculated in each group and stochastical analysis were attempted according to these values. We fitted the equation, y=ax+b for the absolute value analysis, logy=αlog x+log b for allometric analysis.As shown in Figure 1, the differences between the girth of chest during inspiration (GCI) and GCR become smaller as the GCR increases. On the contrary, the differences between the girth of chest during expiration (GCE) and GCR become smaller as the GCR decreases.From the test of linearity, GCI and GCE showed the monophasic allometry (Fig. 2). GCI showed the negative allometry against GCR. The coefficient of male (0.88) is smaller than that of female (0.91). We also admitted the negative allometry in GCE. The coefficients of male and female were 0.98 and 0.91 respectively. In both sexes, GCI showed more extensive negative allometry than GCE.In sagittal diameter of chest, the regression coefficient in male (0.240) is larger than that in female (0.114). But there is no significant differences between the coefficients of transverse diameter of chest in both sexes (Fig. 3).From the allometric analysis we admitted the distinct negative allometry of transverse diameter of chest in both sexes as shown in Figure 4. On the contrary, the allometry of the sagittal diameter of chest in female showed the extensive negative, in spite of the isometry in male.From these results it is reasonable to presume that in female the group of larger GCR have relatively larger sagittal diameter of chest.In the vital capacity, there are no continuity of between the fitting lines both sexes as be shown in another items (Fig. 5). An inclination of the fitting line of female is more gentle than that of male

Allometry · Biology · Combinatorics · Expiration · Girth (graph theory) · Respiratory system · Anatomy · Ecology · Mathematics · Medical Imaging and Analysis · Radiation Dose and Imaging · Scoliosis diagnosis and treatment