THE ESTIMATION OF SEX FROM LUMBAR SPINE

Abstract

The estimation of the sex of an unknown individual forms an essential part of biological identification in forensic anthropology, but is often hindered by poor preservation of the skull or pelvis. This study explores the relationship between the spinal dimensions of the lumbar spine and biological sex through means of osteometry. Osteometric data from a total of 3645 dry lumbar vertebra (N=385 and N=278 male and female skeletons respectively) were collected from four anatomical collections of known age and sex individuals located in Africa and North America. The Maximum Lumbar Length (ML) was determined for each of the five vertebrae and the measurements were then combined to provide an average for each individual. Of the single vertebrae, the ML dimensions of L1 provided the greatest accuracy when comparing the estimated sex against the known sex of the individual (80.3%). However, maximum lumbar length proved more accurate when the measurements for the five vertebrae were combined (82%). This study proposes possible usages of the sexually dimorphic features of the lumbar spine of Homo sapiens in challenging clinical, anatomical, forensic and osteoanthropometric cases in which either one or combination of factors such as decomposition, scavenging, burning and dismembering of human bodies provide no other feasible clues for identification of sex. Further examination and detailed studies of sexually dimorphism in the spine are needed to fully develop this method of forensic use, and may also have potential applications in evolutionary biology, possibly providing new information on sex specific bipedal adaptations.Grant Funding Source: AAA