The shoulder blade, or scapula, is a large, flat, triangular bone located on the posterior side of the ribcage, on either side of the spine. It is one of the three main bones forming the shoulder girdle, connecting the clavicle (collarbone) to the humerus (upper arm bone) and forming part of the shoulder joint socket.

The scapula has three surfaces, three borders, and three angles. Key anatomical features include the spine of the scapula, the acromion, the coracoid process, and the glenoid cavity (which articulates with the head of the humerus). It serves as an attachment site for more than a dozen muscles, ligaments, and tendons that provide mobility and stability to the shoulder.

The scapula plays a crucial role in enabling a wide range of shoulder movements and supporting the function of the upper limb.