Abstract:

Various anatomical variations often occur on the anterior aspect of the femoral neck, and some features have been the subject of much research because of their possible relevance to ancient human behavior, such as Poirier’s facet. However, the definition of these non-metric traits and the reasons for their occurrence are controversial. In this paper, we combine the previous studies and practical observation experience to sort out the observation standards for the three common non-metric traits on the anterior femoral head-neck junction, namely, Poirier’s facet, plaque and Allen’s fossa. This paper observed eight groups of femur samples from archaeological sites in northern China dating from the Neolithic Age to the Ming-Qing period, and after statistics on the occurrence rate of each feature, we found that all three features showed significant gender, age, and population differences. Poirier’s facet and plaques were commonly found in males and occurred more frequently in middle-aged and older adults, and Allen’s fossa was more common in females and more prevalent in young adults. Combined with the anatomy of the hip joint and the daily activities of ancient populations, the presence of the Poirier’s facet and plaque may be associated with hip joint activity. Hip extension and external rotation increase the pressure on the iliofemoral ligament and compress the femoral head at the neck. With hip extension, external rotation and flexion, the femoral neck comes into contact with the acetabular rim, creating a pressure area. Femoroacetabular impingement is another possible factor that contributes to the appearance of Poirier’s facet and plaques. The formation of these two traits does not correlate well with behaviors such as riding horse and squatting. Allen’s fossa is different from both the morphological characteristics and the location of appearance of the Poirier’s facet and plaques, with Allen’s fossa appearing as early as childhood, possibly as a result of higher levels of stress in the individual’s survival, but more validation is needed from a sample of children. Taken together with the history of the research of Poirier facet and the reasons for its formation, the original translation of Poirier’s facet is not appropriate any longer. The significant differences in the performance of non-metric traits at the anterior aspects of the femoral head-neck junction between different populations suggest that there is potential for reconstructing activity patterns, health conditions and lifestyles of ancient people.

Key words: Poirier’s facet, riders’ facet, non-metric trait, femoral neck