[Cineradiographic study of wrist motion].

To make clear the kinematics of the wrist in flexion-extension and radial-ulnar deviation, a cineradiographic study was carried out on twenty normal hands. The intercarpal angles were measured on each picture of the cineradiogram. The relationship between the wrist angle and the intercarpal angles were calculated by a micro-computer giving a 5th degree regression curve. From the maximal dorsiflexion to the neutral position, the wrist moves in the radiocarpal joint more than in the midcarpal joint, while, from the neutral position to the maximal palmar flexion, the wrist moves more in the latter. From the neutral position to the maximal radial deviation, the wrist motion occurs in the midcarpal joint more than in the radiocarpal joint, while, from the neutral position to maximal ulnar deviation, the wrist motion occurs equally in the two joints. The movements of the carpal bones were regulated by the tension and the relaxation of the carpal ligaments.