[The relative length of the radius and ulna at the wrist joint]

The average relative length of radius and ulna on the wrist joint was measured. The 922 examined joints (637 patients) were divided into groups corresponding to age. Up to the age of 50 the relative length of the both forearm bones is the same. Then the ulna surpasses the length of the radius a little. The maximum difference amounts to 1 mm. We support the cause in a decrease of cartilage thickness of caput radii and capitulum humeri which is greater than a simultaneous decrease of cartilage thickness in humero-ulnar joint. In senility the small difference disappears again. The standard deviation is rather considerable, it means a great individual fluctuation. Besides we have examined the elevation of processus styloideus radii et ulnae and their distance. This values were very constant.