Morphometric variation and ray allocation of human proximal hand phalanges
Karakostis, Fotios Alexandros; Lorenzo, Carlos; Moraitis, Konstantinos
Abstract In previous studies, the anatomy of proximal hand phalanges has been described and techniques of anatomical allocation have been developed. However, these rely on the observation of small phalangeal traits without providing a multivariate analysis of morphological variation. In bioarchaeological contexts, the form of these distinctive traits is often not clear and the use of alternative supplementary methods is vital. This study aims to conduct a multivariate analysis of proximal phalanges and introduce a new methodology of ray allocation for isolated proximal phalanges. The sample utilized involves 60 Greek individuals of the Athens Collection as well as 48 African-American and 49 European-American individuals of the Hamann-Todd collection. Multivariate analyses of variation were performed to assess differences across three population samples, sexes, and the five hand rays. Subsequently, a metric method for identifying the ray of isolated specimens was developed and a blind test was utilized to assess its value. The results demonstrated that there is extensive overlapping among population samples and substantial sexual dimorphism. Across rays, three morphological groups were observed. Identifying correctly the 1st and the 5th rays was possible in 100% and 93.0% of the cases, respectively. The classification accuracy for the 2nd ray reached the 91.0%. Sex-specific functions provided moderate accuracy for the 3rd and 4th rays, which ranged from 77.2 to 83.3%. The blind test indicated that the combined use of morphological and metric methods can provide a more certain anatomical allocation of proximal hand phalanges than each of these approaches separately.