Morphological variations in ulnar supinator crests and fossae as identifying markers of occupational stress

Recent morphometric studies of ulnae of prehistoric skeletal remains from populations known to have used spears, atlatls, and similar projectile weapons for hunting and warfare reveal a high incidence of hypertrophy of the ulnar crest, to which the supinator muscle is attached, along with pronounced depth of the adjacent supinator fossa, especially in the upper extremities of males. Similar features occur in the right ulnae of living persons of both sexes who are habitually engaged in certain occupational and athletic activities involving angular displacement of the forearm as a result of medial rotation of the arm at the shoulder, shoulder and arm rapid extension, and abrupt shifts from forearm supination to pronation. Aside from its forensic science implications in determination of right- or left-handedness as a trait peculiar to the individual, observation of these markers of stress on the proximal end of the ulna are significant in identification of skeletal remains of persons known to have engaged in specific brachial activities during life. The biomechanics of these movement patterns and activities in which they occur, when properly interpreted, are relevant to forensic science problems of individual identification and paleoanthropological studies of occupational stress factors in extinct populations for which a skeletal record is available.