The impact of activity on pelvic age‐at‐death estimation

AbstractThis study assesses whether greater levels of physical activity result in increased rates of degenerative change in the pubic symphysis and the iliac auricular surface. The sample comprises 131 skeletons from the Athens Collection. Skeletal age‐at‐death was estimated from the pubic symphysis and the iliac auricular surface. Skeletal activity was assessed using femoral cross‐sectional geometric (CSG) properties and fibrocartilaginous entheses. The association between skeletal age stages, CSG properties and entheseal changes (EC) was tested using Spearman correlation followed with partial Spearman correlation controlling for the effect of documented age‐at‐death and estimated body mass, as well as generalised linear models. Moreover, Kruskal–Wallis tests were used to compare the EC and CSG values among individuals who were underaged, correctly aged and overaged using the pubic symphysis and the iliac auricular surface. Our results show a negative correlation of skeletal age stages with particular CSG properties, implying a decrease in skeletal rigidity as age increases, and a positive correlation with EC scores, suggesting that older individuals exhibit more pronounced EC. Controlling for documented age‐at‐death and body mass produced low correlation coefficients and very few statistically significant results. The difference in EC and CSG values among underaged, correctly aged and overaged individuals was significant only for ECs in individuals over 50 years old. The present study highlights that the effect of activity on pelvic age markers is not pronounced, because a limited association between activity and skeletal degeneration in the pubic symphysis and iliac auricular surface was found. Considering the difficulty in identifying past occupations skeletally, our study supports that this often missing parameter in past osteobiographies does not affect skeletal age estimation. Moreover, our results suggest that taking into account the EC scores when evaluating skeletal age can provide further insights in age‐at‐death estimation in older individuals.