Photogrammetric determination of center of gravity of Down's Syndrome and normal individuals: A validation study

A total of 90 individuals (50 normal and 40 Down's Syndrome) served as subjects in the validation of a photogrammetric technique for determining total body and segmental centers of gravity. The Ss (n = 10) were placed equally into age groups (6-10 yr, 11-18 yr, adult females, adult males) except for the normal adults (15 male, 15 female). Eighty Ss, 40 Down's Syndrome and 40 normal, were evaluated on total body center of gravity by the center of gravity board and photogrammetric techniques. The normal adults (n = 30) were evaluated for segmental centers of gravity by the immersion and photogrammetric techniques. The photogrammetric technique for determining total body center of gravity was considered to be valid (r = .97, less than 5% error). The validity of photogrammetric technique for determining segmental centers of gravity was not fully established (r = .47-.72, percentage of error ranged from -8.9% to 1.1%). Total body and segmental centers of gravity of Down's Syndrome and normal Ss, determined by the photogrammetric technique, were compared by age and sex to existing normative data. The results indicated (a) the Down's Syndrome Ss were found to have an overall lower center of gravity when compared to the normal Ss, and (b) the differences between the groups increased with age.