Adolescent spurts in body dimensions: Average and modal sequences

The sequence of growth spurts in 11 body dimensions was examined in 101 Pol ish adolescents, 52 males and 49 females, followed longitudinally from 11-1 8 years. The dimensions included weight; stature; symphyseal height; biacro mial and bicristal breadths; and arm, forearm, chest, thigh and calf circum ferences. Upper segment length was estimated as stature minus symphyseal he ight. Measurements were takes quarterly from 11-14 years, and annually or l ess frequently thereafter. Growth curves were fitted to individual longitud inal observations using kernel regression to derive estimates of ages at pe ak velocity (PV) and peak velocities. Within each sex, mean ages at PV were used to define the average sequence, while the most frequently observed se quence of PVs in individuals was used to define the modal sequence. Average and modal sequences differed, the latter probably reflecting individual va riability in timing. The spurt in the estimate of leg length (symphyseal he ight) occurred prior to that for stature in males (first in the sequence) a nd was nearly coincident with that for stature in females (second in the se quence by 0.01 years). The timing of spurts in other dimensions within each sex was more variable in both average and modal sequences. (C) 1999 Wiley- Liss, Inc.