American Registry of Radiologic Technologists (ARRT) Practice Exam

Which carpal bone is the most palpable?

1. Pisiform

2. Capitate

3. Navicular

4. Triquetrum

The correct answer is: Pisiform

The pisiform bone is the most palpable carpal bone due to its location and unique characteristics. It is a small, pea-shaped bone situated on the palmar side of the wrist, where it forms a visible prominence that can be felt under the skin. The pisiform acts as a sesamoid bone, specifically in the tendon of the flexor carpi ulnaris muscle, which contributes to its accessibility to palpation. In contrast, the other carpal bones, while they have specific locations and functions, are not as easily felt through the skin. The capitate, although the largest carpal bone and centrally located, is deeper within the wrist and covered by other structures. The navicular (also known as the scaphoid) is located more proximally and is typically harder to palpate without specific maneuvering. The triquetrum, located just proximal to the pisiform, is also not as readily palpable due to its position and the overlaying tissue. Therefore, the distinct location and the projection of the pisiform make it the most palpable carpal bone.