The timing and duration of adolescent growth.

The adolescent growth of 212 randomly selected Swedish urban children has been investigated by using a graphical analysis of unsmoothed increments of height. The adolescent growth period has been divided into the pubertal spurt and the postpubertal period. On average, the pubertal spurt began at 10.0 years in girls, and 12.1 years in boys and ended at 14.8 years and 17.1 years, respectively. In both sexes peak height velocity occurred two years after the onset of the spurt (12.0 years and 14.1 years). Growth terminated at 17.5 years in girls and 19.2 years in boys. The standard deviation of the age at the occurrence of the various growth events is about one year in both sexes. The duration of the spurt did not differ between the sexes but the postpubertal period was significantly longer in girls. To include the total range of adolescent growth variability, the age range 6 -- 20 years in girls and 9 -- 23 years in boys must be considered in a Swedish population.