escápula

The escapula, commonly known as the shoulder blade, is a large, triangular bone located on the posterior aspect of the thorax, covering the upper and posterior part of the ribs. It connects the humerus (upper arm bone) with the clavicle (collarbone). This anatomical structure plays a crucial role in enabling a wide range of motion in the shoulder joint, allowing for movements such as elevation, depression, protraction, retraction, and rotation of the arm.

The escapula is composed of several key features. The body is the main flat part of the bone. Projecting from the body are the spine of the scapula, a prominent ridge that divides the posterior surface into the supraspinous and infraspinous fossae. The acromion is a large, bony projection that forms the highest point of the shoulder and articulates with the clavicle at the acromioclavicular joint. The coracoid process is a hook-like projection that extends anteriorly and superiorly, serving as an attachment point for several muscles and ligaments. The glenoid cavity is a shallow, pear-shaped depression that articulates with the head of the humerus, forming the glenohumeral joint, the primary joint of the shoulder.

Numerous muscles attach to the escapula, including the deltoid, trapezius, rhomboids, serratus anterior, supraspinatus, infraspinatus, teres minor, teres major, and subscapularis. These muscles are essential for stabilizing the shoulder joint and facilitating complex arm movements. Injuries to the escapula itself are relatively rare, but fractures can occur due to significant trauma. More common are issues related to its mobility and the surrounding musculature, which can lead to conditions like scapular dyskinesis.