The neck of the radius is a short and narrow cylinder of bone between the expanded head and the radial tuberosity on the shaft.
The radial tuberosity is a large blunt projection on the medial surface of the radius immediately inferior to the neck. Much of its surface is roughened for the attachment of the biceps brachii tendon. The oblique line of the radius continues diagonally across the shaft of the bone from the inferior margin of the radial tuberosity.
Proximal end of the ulna