[Significance of the upper segment of the body: a hypothesis to consider].

Considering the unquestionable echosensitivity of the lower segment and the great resistance that the upper segment shows to the negative action of the environmental factors, the study of the final height predictions was carried out based on the magnitude of the present height of the lower and the upper segments under the hypothesis that such predictions, but specially those involving the latter, would express the minimal genetic potential that each group would have as an average and that would approach considerably the one established for 18 year -old subjects selected to design reference patterns. For such purpose, 1 011 females, from 12 to 20 years of age and belonging to different socioeconomical levels were studied. In those belonging to the highest level, (normal growth) there were no significant differences in predictions made; on the other hand, subjects of the lowest level showed very noticeable differences in spite of which, predictions made, considering the upper segment, did not differ significantly from those made for the other group, nor with the height accepted as normal in reference patterns (160.6 +/- 7.4 cm).