Adolescent spurts in body dimensions: Average and modal sequences.

The sequence of growth spurts in 11 body dimensions was examined in 101 Polish adolescents, 52 males and 49 females, followed longitudinally from 11-18 years. The dimensions included weight; stature; symphyseal height; biacromial and bicristal breadths; and arm, forearm, chest, thigh and calf circumferences. Upper segment length was estimated as stature minus symphyseal height. Measurements were taken quarterly from 11-14 years, and annually or less frequently thereafter. Growth curves were fitted to individual longitudinal observations using kernel regression to derive estimates of ages at peak velocity (PV) and peak velocities. Within each sex, mean ages at PV were used to define the average sequence, while the most frequently observed sequence of PVs in individuals was used to define the modal sequence. Average and modal sequences differed, the latter probably reflecting individual variability in timing. The spurt in the estimate of leg length (symphyseal height) occurred prior to that for stature in males (first in the sequence) and was nearly coincident with that for stature in females (second in the sequence by 0.01 years). The timing of spurts in other dimensions within each sex was more variable in both average and modal sequences. Am. J. Hum. Biol. 11:287-295, 1999. Copyright 1999 Wiley-Liss, Inc.