The scaphoid bone is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist (also called the lateral or radial side). It forms the radial border of the carpal tunnel.

The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. It is approximately the size and shape of a medium cashew.

The carpal bones function as a unit to provide a bony superstructure for the hand. The scaphoid is also involved in movement of the wrist. It, along with the lunate, articulates with the radius and ulna to form the major bones involved in movement of the wrist. The scaphoid serves as a link between the two rows of carpal bones. With wrist movement, the scaphoid may flex from its position in the same plane as the forearm to perpendicular.

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