Statistical analyses of measurements were used to evaluate congenital asymmetry and activity-related change in 100 pairs of humeri and 112 pairs of femora. Bone pairs in samples from the Nary Rose and an earlier medieval site in Norwich were subdivided into age categories and their archaeological groups for analysis. Internal bone dimensions were determined from radiographs and compared with those of a modern group of divers. Muscle insertions were ranked and femoral morphological traits were recorded. Differences were tested at the p<0.05 level of confidence. Congenital asymmetry was accepted from earlier work for maximum length of the humerus. Asymmetries decreased with age in the humerus and to a lesser extent in the femur. The humerus was shown to have significant right-sided dominance while the femur was more symmetric. Accepted methods of measuring femoral torsion were demonstrated to be inadequate. Femoral morphological traits were shown to be affected by environment. Significant results obtained from new measurements may be attributable to patterns of activity In the Nary Rose sample. These individuals were significantly taller and larger than those of the Norwich sample. Selection, diet and activity are discussed as possible explanations for these increases. Statistical comparison of compatible groups may reveal patterns of activity, if the occupations in the groups are known.