Henry Gray (18251861). Anatomy of the Human Body. 1918.
segment of a cone, the axis of which extends from the center of the head of the radius to the middle of the head of the ulna. In this movement the head of the ulna is not stationary, but describes a curve in a direction opposite to that taken by the head of the radius. This, however, is not to be regarded as a rotation of the ulnathe curve which the head of this bone describes is due to a combined antero-posterior and rotatory movement, the former taking place almost entirely at the elbow-joint, the latter at the shoulder-joint.
FIG. 336 Vertical section through the articulations at the wrist, showing the synovial cavities. (See enlarged image)
The wrist-joint is a condyloid articulation. The parts forming it are the lower end of the radius and under surface of the articular disk above; and the navicular, lunate, and triangular bones below. The articular surface of the radius and the under surface of the articular disk form together a transversely elliptical concave surface, the receiving cavity. The superior articular surfaces of the navicular, lunate, and triangular form a smooth convex surface, the condyle, which is received into the concavity. The joint is surrounded by a capsule, strengthened by the following ligaments:
The Volar Radiocarpal.
The Ulnar Collateral.
The Dorsal Radiocarpal.
The Radial Collateral.
The Volar Radiocarpal Ligament (ligamentum radiocarpeum volare; anterior ligament) (Fig. 334).This ligament is a broad membranous band, attached above to the anterior margin of the lower end of the radius, to its styloid process, and to the front of the lower end of the ulna; its fibers pass downward and medialward to be inserted into the volar surfaces of the navicular, lunate, and triangular bones, some being continued to the capitate. In addition to this broad membrane, there is a rounded fasciculus, superficial to the rest, which reaches from the base of the styloid process of the ulna to the lunate and triangular bones. The ligament is perforated by apertures for the passage of vessels, and is in relation, in front, with the tendons of the Flexor digitorum profundus and Flexor pollicis