Quantitative sex differentiation of morphological characteristics in children aged 11 to 14 years.

Sex is one of major factors of individual variability. In kinesiology, we explore and record changes brought on by growth and development, so we will use a sample of 1020 subjects, at the age of powerful changes caused by sexual maturation, to investigate differences in morphological characteristics of children and to determine the significance of differences based on sex. The aim of this transversal research was to determine the sex differentiation of morphological characteristics in 5th and 8th grade students of elementary school as well as structural differences between the sexes. Differential sex differences in the structure of morphological parameters surely exist, and in their basis lies in a different temporal, or periodical onset of development phases, while multivariate analysis of variance for each age removes any doubt about these differences being more than obvious. Differences in the structure of discriminant function in children aged 11 are conditioned primarily by diverse structuring of transverse dimensions, in a way that boys are distinctly superior in knee diameter, and girls in bicristal diameter. As early as the age of 11, it can clearly be recognized that pre-puberty had already progressed in girls, which is then followed by puberty. At the age of 12 girls are already experiencing a puberty spurt, which is manifested in further development of bicristal diameter and longitudinal dimensionality of the skeleton, particularly of lower extremities. Thirteen year old boys are on the verge of a puberty spurt, which is manifested through the development of longitudinal dimensionality, and to a lesser extent, of transverse dimensionality of the skeleton. Secondary discriminant distinctiveness can be observed continuously across all variables assessing the dimension of deposition of fat reserves, and also, absolute values of measures of subcutaneous fat tissue are more prominent in female students. It is indicative that subcutaneous fat deposits are still secondary determinants in distinguishing groups of children according to sex, in a way that this dimension is continuously expressed more perceptibly in girls.