A Cross-sectional Growth Study of Forearm Length and Tibial Length in an Indigenous Andean Population of 6 to 19 Years of Age.

Abstract

Patterns of growth in forearm length and tibial length were studied in 149 school-children of Aymara ancestry (73 boys and 76 girls), aged 6 to 19 years. The investigation was based on a cross-sectional survey performed in 1987 in the rural community of Putre (3,530 m), northern Chile. The results show that there is little sexual dimorphism over the age period of 6 to 13 years, while sex differences are more pronounced between the ages of 14 and 17 years, both for forearm length and tibial length, with boys having higher means. Correspondingly, the maximum values achieved for both measurements are greater in boys than in girls. The growth spurt begins about two years earlier in girls than in boys. In both sexes, tibial growth precedes forearm growth. The analysis of growth relationships between forearm length and tibial length in relation to other measurements shows higher positive correlations to stature than to sitting height. Inter-populational comparisons between the extremity growth pattern of the Aymara children and that of children of different ethnic ancestry reveal that at all ages, the Aymara have longer forearms in proportion to their tibiae than is the case with children of Asiatic, European and African ancestry. It is suggested that the relatively longer forearms in the Aymara might be related to their larger thoracic dimensions.