This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
By the wrist is meant the constricted portion of the upper extremity by which the hand is joined to the forearm. We will include in its consideration the lower portion of the forearm for about 4 cm. (1 1/2 in.) above the radiocarpal joint, and the joint itself. I he wrist is so constructed as to permit of the movements of pronation and supination of the bones of the forearm, to serve as a support for the hand, and to allow movements of the hand in various directions.