The adolescent – Physical development

Adolescence is a turbulent time in many respects -physically, emotionally and sexually. During the years from approximately the age of 10 to the age of 18 the human body undergoes so many changes it is difficult for the adolescent to keep track of his or her shape and appearance. Growth is rapid and sexual characteristics develop quickly, so that within two to three years the child has become an adult – physically, at least.

The age at which adolescence announces itself by a sudden, rapid increase in height is about 10 years old in girls, and about 12 years old in boys. The onset of menstruation in girls and the first seminal discharge in boys is regarded as the starting point of physical adolescence. This moment generally comes within two years of the initial growth spurt, but as in all the developments of adolescence, there is large variation between different individuals.

The adolescent growth spurt

After the second year of birth, height increases steadily by about six centimetres a year until a pre-puberty growth spurt of height and weight. In girls, the spurt starts at about 10 to 11 years of age, and in boys approximately 12 to 13 years of age. It lasts for about two years. During this burst of growth, girls gain about 16cm and boys 20cm in height. Although a boy’s growth spurt starts later than a girl’s it lasts longer- until about 18 years of age in comparison with about 16 years of age in girls. This is why men are on average taller than women.

The weight increase lags behind the change in height in both sexes and starts later in boys. In both sexes, the feet and hands grow first, then the forearms and calves, followed by the chest and hips. Next, the shoulders, particularly in boys, develop. Lastly, the trunk lengthens and the chest deepens, although the growth of breasts in girls to some extent masks the chest growth. These growth spurts change the bodily shape to the extent that the differences between the two sexes become more physically apparent. The pelvic region in girls grows more than their shoulder girdle, becoming wider, more spacious and deeper than the male pelvis. Also, fat is deposited over the hips, resulting in the characteristic female contours. In boys, the reverse takes place and the shoulders become wider and heavier.

Parents should not neglect the rapidly growing feet of adolescents, who are often more interested in wearing fashionable shoes, which may cramp and distort their feet, than in healthy and practical footwear. Complaints such as corns, hammer toes or bunions may occur, and distortion of feet during adolescence may not be curable later on.

Another problem that may occur as a result of ‘vanity’ is when adolescent boys and girls refuse to wear glasses when they need them. They may consequently suffer from headaches and severe eyestrain. During early adolescence, boys and girls are generally not at their most physically attractive. The contours of their body are angular, their complexion spotty, their hair dull, and their movements often badly co-ordinated and lacking in rhythm. Boys usually have longer legs than girls because during the pre-pubescent period, their legs grow faster than their trunk. All the physical changes to do with growth in boys and girls are caused by the secretion of the human growth hormone from the pituitary gland and (to a lesser extent) by the sex hormones. Sometimes the pituitary gland, which is attached to the base of the brain, malfunctions.

Underproduction of the growth hormone can lead to dwarfism, and overproduction to gigantism. Both these conditions can be treated if detected at an early stage.