A mixed longitudinal study of physical growth in girls--I.

A total of 492 apparently normal healthy Punjabi girls belonging to upper socio-economic status between 5-15 years of age were selected from the schools for the study of physical growth. Twenty one measurements were made on each girl. Girls below the age of 13 years were examined five times at interval of six months each. Beyond 13 years, only those girls who had not attained menarche, were followed-up 6 monthly. The linear and circumferential measurements followed similar pattern while skinfold thicknesses showed different pattern. Each linear and circumferential measurement and weight increased progressively from age 5 to 15 years. Annual growth gain per year was slow upto 9/10 years followed by a rapid growth with a peak velocity between 11-13 years of age. Thereafter, growth rate declined. The skin-fold thicknesses showed decrease in absolute values upto 10 years of age. Beyond 13 years of age, these increased rapidly. However, no peak velocity in either of the skinfold was detected. Thus, three periods of growth rate, viz., preadolescent (age 5-9 years); adolescent (10-13 years) and post adolescent (beyond 13 years) could be identified.