Metric pair-matching of calcanei in cases of commingled human remains: examining 21st century black, white, and Coloured South African populations

This research aimed to establish an accurate method of osteometric pair-matching calcanei in White, Black, and Coloured South Africans. Paired calcanei of 419 adult individuals (210 males, 209 females) were utilized. Both the left and right calcanei of 139 White South Africans (70 males, 69 females), 140 Black South Africans (70 males, 70 females), and 140 Coloured South Africans (70 males, 70 females) were examined. Six measurements were collected from each calcaneus. The variables that exhibited the least amount of directional and absolute asymmetry were maximum length (MAXL) and middle breadth (MIDB). The variables that exhibited greater degrees of directional and absolute asymmetry were articular facet dimensions (dorsal articular facet length (DAFL), dorsal articular facet breadth (DAFB), middle articular facet length (MAFL), and middle articular facet breadth (MAFB)). There were no statistically significant differences in directional and absolute asymmetry between sexes for most variables. There were statistically significant differences in ­absolute asymmetry between the three South African populations for some variables. Therefore, population-specific osteometric pair-matching methods are necessary. The statistic M was utilized to create reference tables for osteometric pair-matching. The values of M for MAXL for pair-matching comparisons resulted in the greatest reduction in the number of possible pairs with acceptable false rejection rates. The osteometric pair-matching tables from the current study can be utilized, in combination with visual pair-matching techniques, to assist in the resolution of commingled remains cases.