The trapezium (wrist bone)

What it does

The trapezium sits at the thumb end of the second row of wrist bones. The bone of the thumb's palm rests on it in a saddle-shaped joint, which lets the thumb swing across the palm to touch each fingertip.

Why it matters

This joint takes a lot of wear, and it is one of the commonest places for arthritis in the hand, making jar-opening and pinching painful.

Nearby

• The scaphoid (wrist bone)
• The palm bones
• The ball of the thumb

Read more

• Trapezium — Wikipedia