A Case of Marked Bilateral Asymmetry in the Upper Limbs of an Upper Palaeolithic Male from Barma Grande (Liguria), Italy

Abstract

Barma Grande 2, a male skeleton of upper palaeolithic age from Balzi Rossi (Liguria, Italy), shows a marked degree of upper limb bilateral asymmetry. Similar cases of asymmetry in palaeolithic hominid fossils have variously been attributed to high levels of behavioural asymmetry (related to handedness) or a pathologically induced alteration of upper limb skeletal remodelling processes. As in many of these cases, the skeleton from Barma Grande lacks any indications of trauma or pathology in the smaller left limb. Consideration of the morphology of the preserved upper limb elements and a comparative analysis of asymmetry in normal and pathological male palaeolithic fossils and normal recent human samples suggests that the asymmetry in Barma Grande 2 was a secondary effect of trauma or pathology in the left side. The degree and pattern of asymmetry in numerous humeral and ulnar measurements indicates an adult onset of altered loading patterns. Several possible aetiological factors are considered, with the most probable being an entrapment neuropathy, direct trauma to one or more muscles about the shoulder, or possibly glenohumeral joint instability.