Neandertal radial tuberosity orientation.

Examination of adult and immature Neandertal radii demonstrates that the medial versus anterior orientations of their radial tuberosities fall within recent human ranges of variation, but on the average their radial tuberosities are significantly more medially, as opposed to anteromedially, oriented. This more posterior positioning of their radial tuberosities implies a maintenance of an effective moment arm for M. biceps brachii through the full range of supination, an interpretation which fits with the hypertrophy of and increased moment arms for their forearm pronator muscles. It is an additional indication of the muscular hypertrophy evident elsewhere in Neandertal upper limbs.