Pisiform bone joint, articulating with the triquetral bone. It is on a plane anterior to the other carpal bones and is spheroidal in form. The pisiform bone has four surfaces: Unlike the other carpal bones, the pisiform is not involved in movement of the wrist. The etymology derives from the Latin "pīsum" which means "pea". All other tetrapods have pisiform, being the most common sesamoid. As compared with apes, which have an elongated Pisiform, humans have a shorter pisiform bone. This is due to the loss of the single growth plate typically found in other mammalian pisiforms. This may be because of
Hamate bone usually a hairline fracture, commonly missed on normal X-rays. Symptoms are pain aggravated by gripping, tenderness over the hamate and symptoms of irritation of the ulnar nerve. This is characterized by numbness and weakness of the pinkie finger with partial involvement of the ring finger as well, the "ulnar 1½ fingers". The hook of hamate is particularly prone to fracture-related complications such as non-union due to its tenuous blood supply. It is also a common injury in baseball players. Several professional baseball players have had the bone removed during the course of their careers. This condition has been called "Wilson's