Two donkey's carpi radiographied without contrast media and two donkey's carpi were injected with a mixture of 75 g red lead oxide in 150cc gum milk latex at the radiocarpal joint and with an eventually mixture of 75 g red lead oxide in 150 cc gum milk latex colored blue with metheyline blue stain at the
intercarpal joint, where two depressions were observed medial to the extensor carpi radialis tendon and common digital extensor tendon on the dorsal surface of the carpal joint after being flexed, the needle inserted perpendicular in the depressions.