Bones and Joints

The bones of the hand provide support and flexibility to the soft tissues. They can be divided into three categories:

Carpal bones – A set of eight irregularly shaped bones. These are located in the wrist area.
Metacarpals – There are five metacarpals, each one related to a digit.
Phalanges – The bones of the fingers. Each finger has three phalanges, except for the thumb, which has two.

Joints are formed wherever two or more of these bones meet. Each of the fingers has three joints:

Metacarpophalangeal joint (MCP) – the joint at the base of the finger.
Proximal interphalangeal joint (PIP) – the joint in the middle of the finger.
Distal interphalangeal joint (DIP) – the joint closest to the fingertip.

The surfaces of the bones where they meet to form joints are covered with a layer of cartilage, which allows them to glide smoothly against one another as they move.