Secular changes of chosen somatic variables in children aged 7 to 15 from the rural regions of Zywiec between 1964-1996

The main objective of the paper was the determination of the secular trend of boys and girls from rural regions of Zywiec in the years of 1964-1996. The results indicate that time changes relate to chosen somatic variables as well as body proportions. The intensity of these changes vary depending on the variable. The greatest increment for both sexes were registered for body height and body mass (only average 1.3 cm and 1.1 kg per decade). This increase was higher in case of males and was lower in the rural population in comparison to others. During the years on 1980-1996 the rate of secular changes decreased significantly what reflects very difficult social and economical conditions of Polish rural populations during this period. Secular changes seem to confirm the thesis proposed by Polish antropologists which states that the level of physical development reflects in a very sensitive manner social changes in a given population.