Pressure sensitive Fuji film was used to measure contact areas and pressures in the distal radioulnar joints of cadaveric human arms. Joint pressure and contact areas varied as a function of simulated physiological loading under combinations of seven anatomical positions and four dorsal malunions (0°, 5°, 10°, 20°) of the distal radius. In 75% of the cases, mean pressure decreased 3-44% from intact to 0° malunion. During pronation, there was an increase of 5-28% in mean pressure with increasing dorsal malunion from 5° to 20°. Consistent increases in peak pressure were recorded with pronation (3-27%), ulnar deviation (6-35%), and dorsiflexion (9-28%). Increasing dorsal malunion had a nonlinear effect on contact pressures under all loading conditions. These results should be taken into consideration when evaluating acceptable thresholds for radial deformity in surgical practice.