The trapezium bone is one of the eight small bones that make up the wrist, known as the carpals. It is located at the base of the thumb and plays a crucial role in thumb movement and function. The trapezium is shaped like a trapezoid, which is where it gets its name, and it articulates with the first metacarpal bone of the thumb. This bone is essential for the saddle joint formed between the trapezium and the first metacarpal, allowing for a wide range of thumb motions, including opposition. Proper function of the trapezium is vital for grip strength and hand dexterity.