Sexual Maturation and the Growth of Fat, Muscle and Bone in Girls

In a previous paper a method was described for comparing children in terms of the breadths of bone muscle mass and superficial fat in the leg. Measurements of these three tissue components in this anatomical area were based on a longitudinal series of roentgenograms taken specifically for the study of tissue differentiation. Growth changes sex differences and individual variations in tissue distribution were discussed. It was also suggested that differential tissue distribution may be related to such characteristics as sexual maturation and a preliminary report on this problem has been made. The present paper is concerned with the relationship of breast development in girls to the growth of fat muscle and bone in the leg. In broader terms it is thus a study of the relationships between sexual maturation and body structure as they are reflected by a single maturational criterion and by the tissue distributions in a single body area. Although this report is concerned for the most part with girls between the ages of 7 ½ and 12 ½ years of age certain observations on boys are included. (excerpt)