A study on length of lower limbs of adolescents in postwar Japan by relative growth

In the allometric study in relation to the body height, the proportions of sitting height and length of lower limbs to the body height seem to be kept almost unchanged in postwar years in ages before adolescent growth spurt, but those in ages after adolescent growth spurt seem to have changed year by year, and the changes in a recent quarter of century seem to be more apparent at the ages when the body height approaching the terminal level. As a result, the proportion of length of lower limbs to the body height in adolescents is larger in recent years than in the years just after the war. In the observation of boys and girls at the age 17, the increment of sitting height in the postwar years was rather small, and, accordingly, the abrupt increase in body height after the war was mainly caused by the increase in length of lower limbs and the increase as such seem to have occurred in ages after the adolescent growth spurt. After the war, a precocious tendency became rapidly remarkable and the age of adolescent growth spurt became younger year by year. Along this phenomenom, the growth in sitting height per year decreased gradually in ages after the adolescent growth spurt, while the growth in length of lower limbs per year kept rather a constant value in these ages in spite of increasing tendency of precocity. In short, the advance of the precocious phenomenom caused an increase in length of lower limbs which consisted in the main factor of increase in body height.