Sexing accuracies using proximal and middle phalanges of the hand in a modern south african sample

Abstract

Forensic anthropologists include sex determination as part of their analyses. Hand bones were previously excluded from such studies due to their relatively small size and poor preservation. Scheuer and Elkington (1993) were able to show that metacarpals and the first proximal phalanx are sexually dimorphic, with accuracies ranging from 78.0% - 92.0% and 74.0% - 78.0% respectively. The aim of this study was to determine sexing accuracies using the proximal (PP) and middle (MP) phalanges of the human hand in a South African sample. A total skeletal sample of 200 individuals (100 males and 100 females) was used. Seven measurements were recorded on each bone to an accuracy of 0.01mm. Data were analyzed using SPSS version 11.5. Statistically significant differences (p<0.01) were found between males and females for all variables. In the stepwise discriminant function analysis, the variables selected for proximal phalanges were the antero-posterior midshaft diameter for the first proximal phalanx, the medio-lateral midshaft measurement of the second and fifth proximal phalanges and the antero-posterior base diameter of the third and fourth proximal phalanges. Variables selected for the middle phalanges were the antero-posterior base diameter for the second middle phalanx and the medio-lateral midshaft measurement for the third, fourth and fifth middle phalanges. Classification accuracies for proximal phalanges using the stepwise analysis ranged between 80.6% and 84.0% (males) and 85.9% to 88.8% (females), with the highest accuracies obtained for PP1 (males and females) and PP3 (females). Direct analyses for proximal phalanges using single variables produced accuracies ranging from 74.5% to 85.0% (males) and 86.6% to 88.9% (females). Classification accuracies for middle phalanges using the stepwise analysis, ranged between 77.6% and 85.0% (males) and 85.4% to 86.7% (females), with the highest accuracies obtained for MP3. Direct analyses for middle phalanges using single variables produced accuracies ranging from 71.7% to 79.2% (males) and 83.3% to 85.4% (females). In conclusion, these results compare with those of previous studies indicating that these bones can be used to determine sex