Changes of body proportions in the growth process of Riga school age boys

By body proportions we understand the dimensions of the head and the neck, as well as those of the torso and the extremities expressed in the percentage of the total body length. The human body proportions are determined by the skeletal dimensions which are the variables. There are also differences in the growth rate of separate body parts. The determination of body proportions has an important practical meaning in the assessment of one's physical development because only a proportional body succumbs to the chief biomechanical law - consumes the least of energy and is an ideal of health and beauty. The second practical meaning could be the manufacture - clothes, furniture, etc. Proportions play an important role in the spheres of art and sport. The aim of the study is to state the constitutional type of Riga boys in the definitive age. The anthropometric measurements acquired in 2005-2007 from Riga school and pre-school boys were taken for the basis of the current study. 1,359 boys, included in the study, were divided into 12 age groups. Anthropologic measurements were carried out according to the methodical recommendations of R. Martin, K. Sailer and J. Primanis. During the study several anthropometric parameters were analyzed - sizes of the head, the arm, the leg and the torso, as well as the shoulder and the pelvis width and their indices. For the parameters of the boys' body proportions were used the percentage of the value of separate body parts in relation to their definitive value. It shows the different growth rates of these body parts. Adding to this method, proportions of separate body parts against the body height were used. Since the body proportions of boys in different age groups are changeable, and according to the mean statistic parameters, the boys included in the study have different constitutional parameters, they do not correspond to a definite type. However, some main characteristics, which are typical for boys in all age groups are observed. Riga boys are characterized by methodological relatively shorter legs, a short and narrow torso and narrow shoulders. The last two signs are typical of the dolychomorphous type, though it differs from it by shorter legs. Considering the results of measurements and by analyzing the data, we can conclude that: for boys the growth process proceeds harmoniously (balanced) and proportionally; the decisive factor in the body length variations is the length of legs; at the age of 17-18 years the boys' constitutional type corresponds to that of dolichomorphous, except for the length of legs which are shorter and corresponds more to the mesomorphous type.