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Growth Patterns and Physical Plasticity in Adolescent Laborers
Izzet Duyar
Sažetak
Data about the effects of working environment and excessive physical loads on human growth and constitution are insufficient.
Although there are a few studies which link growth retardation in children’s stature and long bones to their
exposure to hard labor, it is difficult to discern whether the detrimental effects of compressive forces on growth result solely
from severe compressive stresses or from the subjects’ poor economic and substandard nutritional conditions as well.
The aim of this study was to clarify this issue by comparing the anthropometric dimensions of laboring and non-laboring
adolescents; both groups came from lower socioeconomic strata and were subject to poor living conditions. The laboring
group consisted of 532 male apprentices aged 13.5–18.5, and the control group, of their 451 non-laboring peers who were
attending school during the period of observation. Body weight, 3 vertical dimensions (stature, upper and lower limb
lengths), 2 diameters (elbow and knee breadths), and 3 circumferences (contracted and relaxed upper arm girth and calf
girth) were measured. In addition, relative growth according to the body height for each variable was computed, since relative
variables are more valuable in evaluating the effects of excessive loading on the human body. The analyses showed
that all vertical dimensions of laboring adolescents lagged behind those of their non-laboring peers. There were also
clear differences between the two groups with regard to relative diameters and girths. The pressure effects of physical activity
stimulate the transversal growth of the long bones. Similarly, circumferences, especially contracted upper arm girth
relative to stature, are more developed in the laboring group than in the non-laboring group. These findings suggest
that excessive workloads retard adolescents’ vertical growth, especially in upper parts of the body, but that they stimulate
transversal growth of the long bones and muscle development.
Ključne riječi
physical plasticity; child labor; physical growth; mechanical loading; body proportions
Hrčak ID:
27189
URI
Datum izdavanja:
7.7.2008.
Posjeta: 1.175 *