What are the Carpal Bones?

The human wrist is composed of eight separate bones that link together -- the carpal bones. Two of the carpal bones create the wrist joint with the ulna and radius bones of the forearm, while the remaining six form the palm. Each of the carpal bones helps enable the many movements of the hand and wrist.

1. Classifications

There are multiple ways to classify the eight carpal bones. Medically and biomechanically, it makes the most sense to view the bones as three columns:

• The radial scaphoid column consists of the scaphoid, trapezium, and trapezoid.
• The lunate column contains the lunate and the capitate.
• The ulnar triquetral column consists of the triquetrum and hamate bones.

Alternatively, most texts and physicians describe the bones as existing on two rows.

• The proximal row contains the scaphoid, lunate, triquetrum, and pisiform.
• The distal row contains the trapezium, trapezoid, capitate, and hamate.