Researchers from Boston University School of Medicine (BUSM) have shown how the distal humerus (elbow) can be used to determining sex in skeletal remains, whilst also highlighting population differences.

Forensic anthropologists estimate the biological profile (sex, ancestry, age, and stature) of skeletal remains for the purpose of identification. Sex is one of the most important components of this profile as it can narrow the pool of missing persons significantly in certain forensic contexts. Sex is typically determined by the shape and features of the pelvis or skull as well as long bone measurements.

“However, many of the areas on the skeleton that are used for sex estimation may be missing or damaged due to trauma, poor preservation, animal scavenging and nature of the incident (explosive). Therefore, it is important to examine other areas of the skeleton that preserve well and are potentially sexually dimorphic (show differences between females and males),” explained author Dr Sean Tallman, assistant professor of anatomy and neurobiology at BUSM.

For this new research, more than 600 skeletons from a modern, documented collection in Khon Kaen, Thailand were examined. Sex estimation methods using the distal humerus that had been developed on non-Asian individuals were applied to the Thai skeletons.

“We found that the shape of the distal humerus differs between females and males in modern Thai individuals. However, when methods that were developed on non-Asian populations were applied to the Thai skeletons, the methods performed poorly, indicating that there are population differences in the degree of sexual dimorphism in the humerus,” said Tallman.

According to the researchers, accurate biological profile methods need to be established and tested on modern skeletal collections that are closely linked with the skeletons being studied.

“It is important to develop biological profile methods that can help identify individuals from this often neglected region of the world that is susceptible to mass disaster from weather, earthquakes, tsunamis as well as civil unrest,” added Tallman.

Research article: Distal Humerus Morphological Variation and Sex Estimation in Modern Thai Individuals