The postulnar bone, also known as the postaxial bone, is a term used in anatomy to describe the bone located on the side opposite to the thumb (medial side) of the forearm in humans and other mammals. It is one of the two long bones found in the forearm, the other being the radius.
The postulnar bone is situated parallel to the radius and forms part of the skeletal structure that allows the forearm to rotate and bend. It spans from the elbow joint to the wrist joint and contributes to the structure of the wrist. In humans, this bone extends from the medial epicondyle of the humerus, where it articulates with the humerus bone, to the styloid process of the ulna, where it connects to the bones of the wrist.
Its main function, along with the radius, is to provide support and stability to the forearm and wrist, thereby enabling a wide range of movements such as rotation, flexion, extension, pronation, and supination. The postulnar bone also serves as an attachment point for various muscles and ligaments involved in forearm and wrist movements.
In cases of injury or fracture to the postulnar bone, medical intervention may be required to realign and stabilize the bone, typically through the use of casts, splints, or surgical procedures.
