Longitudinal study on growth in height in Polish boys and girls

Physical growth and development of children, determined by endogenous factors (genetic and paragenetic) is modified by numerous exogenic ones. This affects differentiation of ways of growth in individual children. In order to estimate the individual growth patterns and changes in growth rate as well as differences in growth of boys and girls, one must observe the process of growth of the same children and over a period of many years (longitudinal study). Such longitudinal study is the only way to provide information about the variability of growth and growth velocity at each age.