Fluctuating and directional asymmetry in young human males: Effect of heavy working condition and socioeconomic status

Abstract

Many adverse environmental and genetic factors can affect stability of development during human growth. Although the level of fluctuating asymmetry (FA) may be influenced by environmental and genetic stress encountered during this period, directional asymmetry (DA) is largely attributable to differential mechanical loading during bone growth, for example, handedness. I assessed the effects of heavy working conditions and socioeconomic conditions on asymmetry levels in three groups of young human males: 1) individuals employed in the heavy industry sector (n = 104, mean age = 18.48 +/- 0.61 years), 2) individuals who had the same socioeconomic status as the laborers (n = 102, mean age = 18.39 +/- 0.58 years) but were not laborers, and 3) nonlaborers from the higher socioeconomic levels of society (n = 103, mean age = 18.43 +/- 0.67). For all subjects, hand length, hand width, elbow width, wrist width, knee width, ankle width, foot length, foot width, ear length, and ear width were measured. All measurements of the upper extremities in the labor group appeared to exhibit DA; in the other two groups only hand measurements exhibited DA. According to analysis of FA, subjects living in poor conditions exhibited more FA than their nonlaborer peers living in better conditions. In addition, biomechanical pressures due to heavy working conditions of the labor group appeared to cause increased DA in the upper extremities: DA increased with an increase in the number of years working.

Facial asymmetry and genetic ancestry inLatinAmerican admixed populations

“…population. This result seems to be concordant with previous analyses suggesting that there is no single asymmetry pattern in our species (Farkas and Cheung, 1981;Ras et al, 1994;Ferrario et al, 1995;Shaner et al, 2000;Smit~t 2000;Ercan et al, 2008;Klingenberg et al, 2010h;Ozener, 2010b).…”

Fluctuating Asymmetry of Human Populations: A Review

“…Dentition of males was more asymmetric than those of females. There are, however, numerous contradictory findings in the literature on this issue [113][114][115][116][117][118][119][120][121]. Furthermore, random X-inactivation can generate mosaic patterns in females for heterozygous loci on the X-chromosome; this could conceivably increase asymmetry for some traits.…”

“…Several comprehensive studies of nutrition, social status, and fluctuating asymmetry have been conducted in the city of Ankara, Turkey [118,123,128,136]. Özener [118] studied the effects of heavy labor and poor socioeconomic conditions on fluctuating asymmetry in three groups of young males: (1) those from lower socioeconomic classes employed in heavy industry; (2) those from the same socioeconomic classes who were not laborers; and (3) non-laborers from the higher socioeconomic classes.…”

“…Özener [118] studied the effects of heavy labor and poor socioeconomic conditions on fluctuating asymmetry in three groups of young males: (1) those from lower socioeconomic classes employed in heavy industry; (2) those from the same socioeconomic classes who were not laborers; and (3) non-laborers from the higher socioeconomic classes. Ten bilateral measures were taken from 309 young adults.…”

Association between Lateral Epicondylalgia and Upper Extremity Anthropometric Measurements: A Case Control Study

“…Directional asymmetry is the presence of significantly larger upper extremity anthropometric measurements when right and left sides are compared, observed in the playing extremities of racquetball, tennis, baseball and rodeo athletes [7][8][9][10][11][12]. This asymmetry reflects asymmetrical growth of bones and muscles [13][14][15].…”