The tempo characteristics of physical development of saint-petersburg'S boys during early childhood

Dynamic observations of the physical development of children make it possible to ascertain shifts in its indicators due to positive or negative phenomena occurring in society and the environment. The aim of the study was to analyze the characteristics of growth processes based on indicators of physical development (body length and weight, chest and head circumference) in boys in early childhood. The surveyed group included 350 boys born in 2014-2016 living in Saint-Petersburg. Anthropometric data of body length and weight, chest and head circumferences were statistically processed by the parametric (sigma) method and the nonparametric (centile) method. An integral nonparametric assessment of anthropometric indicators made it possible to assess the growth tempo and harmony of the development of boys. 66-83% boys throughout the studied age period are of average growth tempo. The largest proportion of boys with an accelerated tempo of development was found at the age of one and a half years (26,8%) and at the end of early childhood at 2 years and 9 months (22,7%). The smallest group during early childhood are boys with a slower growth tempo (7-22%). To clarify the harmony of the development of boys in early childhood, with different tempo characteristics of growth, anthropometric profiles of each group were constructed. Boys with an average tempo characteristic of growth processes throughout the entire period of early childhood are distinguished by harmonious physical development. Boys with an accelerated tempo of development at the age of one and a half and two years show disharmonious development, total sizes exceed the average values by 2а. Boys with a delayed tempo of development in almost all control age points have disharmonious development, especially at 2 years and 2 years 6 months in terms of length, body weight and circumference of the chest and head below average values by an average of 1,5а. The data obtained testify to the unevenness of the growth and development tempos of the boys' bodies and begin to manifest themselves in early childhood.