Shoulder blade, shoulder blade or shoulder it is a triangle-shaped bone located in the upper part of the chest, or in the shoulder, which together with the clavicle forms the shoulder girdle, allowing the union of each upper limb to the trunk. It is classified as a flat bone and has a translucent part.
In the frontal plane, it has a triangular shape, and has three angles (lower angle, lateral angle and superior angle), two faces (anterior and posterior) and three edges (upper, internal and external).
On its posterior side, there is the spine of the scapula, which can be easily palpated, it also has a coracoid process, which is shaped like a finger and serves for muscle insertion; the coracoid process can be palpated.
The external angle of the scapula has a cavity located laterally, which articulates with the head of the humerus. There is also a scapular notch and three fossae: subscapular (located in a lower position in quadrupeds), infraspinatus and supraspinatus.
The shoulder blade, clavicle and coracoid constitute the shoulder girdle, a set that serves to articulate the forelimbs of tetrapod vertebrates. In higher mammals, the shoulder girdle is composed of the clavicle and shoulder blade, the coracoid being just an apophysis of the shoulder blade.
