Anthropometric asymmetry in normal and mentally retarded males

Abstract

Anthropometric asymmetry was considered in a sample of 202 normal and about 200 mentally retarded males. In addition to height, 11 bilateral measurements of bone, soft tissue and strength were taken. Differences between bilateral measurements were analysed in terms of absolute and signed differences, and in terms of the differences corrected for height. Mentally retarded individuals show greater anthropometric asymmetry than normal individuals in both absolute measurements and those corrected for height. The distributions of the differences, both absolute and signed, are also broader in the retarded, and variances of the left-right differences are greater than variances associated with measurement. Left-right differences between the normal and retarded males occur primarily in the upper extremity; in contrast, side differences in the lower extremity are not great. Within the mentally retarded sample, there are no significant left-right differences among different I.Q. groups. However, there are significant differences among aetiological categories, and those with neurological impairment are more structurally asymmetrical.

Prenatal Psychological Stress, Dermatoglyphic Asymmetry and Pregnancy Outcome in the Pigtailed Macaque (<i>Macaca nemestrina</i>)

“…In 1962, Van Valen [24] applied the concept to the denti tion, and since then more than 25 publica tions have appeared dealing specifically with fluctuating dental asymmetry alone [25], while others have focussed on skeletal di mensions [26][27][28], bone and dental density [29,30], and dermatoglyphic features in cluding ridge counts [31][32][33][34] and the atd angle [35,36], The majority of studies have treated the presence of fluctuating asymme try as evidence for the presence of a stressor during development, in particular prenatal development [28-30, 37, 38], Consistent with this view is the finding that the degree of asymmetry is positively correlated with the magnitude of the environmental stressor [29,39], Some workers, however, have ques tioned the interpretation of fluctuating asymmetry as a general and biologically valid indicator of developmental decanaliza tion on an individual basis [25,40] or as a simple monitor of environmental stress alone [41][42][43]; while others have emphasized the confounding effects introduced into the results by sample size and measurement er ror [25,41,44], It is clear that more experi mental studies are needed to identify the nature of environmental stressors, including those of a psychosocial origin, and the extent of their association, if any, with the presence of increased fluctuating asymmetry.…”

Fluctuating asymmetry and disorders of developmental origin

“…Dermatoglyphics, in contrast, are determined at about 10 weeks of gestation [Penrose and Ohara, 19731 and therefore reflect only events occurring in early development. Other researchers have examined fluctuating asymmetry in anthropometric traits (e.g., ear length, foot breadth, palm breadth, and facial asymmetry) [Malina and Buschang, 1984;Livshits et al, 1988a;Livshits and Kobyliansky, 1989;Livshits and Smouse 1993a,b;Burke and Healy, 19931. Again the problem with interpreting fluctuating asymmetry in this context is the long developmental time of these traits.…”

“…Another genetic mechanism may create susceptibility to fluctuating asymmetry in special circumstances. This is the interruption of co-adapted gene complexes and may be the mechanism responsible for the decreased develop- Kieser [1992] Wilber et al [1993] Mellor [1992]; Markow and Wandler [1986]; Markow Peretz et al [19881 Garn et al [19701 Barden [1980bl Townsend [1983,1987] Woolf and Gianas [1976]; Adams and Niswander 119671 Sofaer [1979]; Adams and Niswander [1967] Barden [1980al Malina andBuschang [1984] and Gottesman [1989] Fluctuating asymmetry Environmental stress Fig. 1.…”

Relationship between inertial features of the upper extremity and simple reaction time in boys and girls aged 17–18

“…Afterward these data were averaged. Also, we measured the greatest and smallest circumferences of both forearms as well as their length from acromion to styloid process, as recommended [37]. Because the regression tables for calculation of rotational inertia (see below) were unilateral we used only the partici pants with negligible variation between left and right sides (less than 0.5 cm).…”