The bone most distal and medial of the hand is the "ulna." The ulna is one of the two bones in the forearm, with the other being the radius. It runs along the inner (medial) side of the forearm and extends down to the wrist, where it forms the bump on the inner side of the wrist called the ulnar styloid process. The ulna plays a crucial role in the structure and movement of the wrist and hand.