The wrist is comprised of eight small bones called carpal bones. These are arranged in two rows: the proximal row (closer to the forearm) and the distal row (closer to the hand).
Proximal Carpal Bones
The proximal row, when moving from the thumb side (radial) to the pinky side (ulnar), includes:
- Scaphoid: A boat-shaped bone located on the thumb side.
- Lunate: A crescent-shaped bone next to the scaphoid.
- Triquetrum: A three-cornered bone located next to the lunate.
- Pisiform: A pea-shaped bone that sits on top of the triquetrum.
Distal Carpal Bones
The distal row, also moving from radial to ulnar, consists of:
- Trapezium: A bone located at the base of the thumb.
- Trapezoid: A smaller bone located next to the trapezium.
- Capitate: The largest carpal bone, located in the center of the wrist.
- Hamate: A wedge-shaped bone on the pinky side, with a hook-like projection.
| Row | Bone | Position |
|---|---|---|
| Proximal | Scaphoid | Thumb side (radial) |
| Proximal | Lunate | Next to scaphoid |
| Proximal | Triquetrum | Next to lunate |
| Proximal | Pisiform | Sits on top of the triquetrum |
| Distal | Trapezium | Base of the thumb |
| Distal | Trapezoid | Next to the trapezium |
| Distal | Capitate | Center of wrist |
| Distal | Hamate | Pinky side (ulnar) |
These eight carpal bones work together to provide flexibility and stability to the wrist. They articulate with the radius and ulna of the forearm as well as with the metacarpal bones of the hand.
