is the joint that connects the hand and the forearm. A person uses the wrist to move the
hand up, down, and sideways. The word wrist also refers to an area of the upper part of
the hand. This area includes eight small bones called carpals.
The carpal bones extend across the hand in two rows of four bones each. Strong tissues
called ligaments bind the carpals in place, but they also permit movement. Three carpals
of the upper row join the radius, one of the two bones of the forearm, to form the wrist
joint. The ulna, the other bone of the forearm, does not connect with the carpals. It
forms a joint with the radius just above the wrist. This joint permits the wrist to rotate
and thus helps turn the palm of the hand up and down.
Cordlike tissues called tendons extend through the carpal
area and connect the finger bones with muscles in the arm. When these arm muscles
contract, they pull the tendons and make the fingers move. The tendons on the palm side of
the carpals bend the fingers. Those on the back of the hand straighten the fingers.
A fall on an outstretched arm may fracture one of the carpals, called the scaphoid bone,
or the radius's lower end. Either injury is called a broken wrist. Many athletes suffer
Contributor: J. Donald Opgrande, M.D., Chairman, Orthopedic Surgery, Univ. of North Dakota
School of Medicine.