1. ANATOMY The anatomy of the shoulder girdle includes seven bones (shoulder blades, clavicles,sternum and upper ends of the humerus), six joints and their corresponding muscles. 1Translated from French to English - www.onlinedoctranslator.com 1.1 OSTEOLOGY ➢ Shoulder blade The scapula has two sides, an articular cavity and two processes, the acromion and thecoracoid. . ● The anterior surface is excavated, it gives insertion almost entirely to the muscle subscapularis. On its internal edge from top to bottom is inserted the large serratededge. The long portion of the triceps originates on its outer edge, under the glenoidcavity, while the long biceps inserts above this cavity. . ● The posterior surface is divided into two fossae by the spine of the scapula. These two fossae give rise to the supraspinatus and infraspinatus. On the outer edge areinserted from top to bottom the long portion of the triceps, the teres minor, the teresmajor and the latissimus dorsi. On its internal edge it gives insertion to the angularand the rhomboids. On the spine of the scapula the trapezius muscle is inserted atthe top and the deltoid at the bottom. . ● The acromion extends the spine of the scapula. It presents on its antero-internal face an articular facet intended for the clavicle. The only muscle inserting in this process isthe deltoid. . ● The coracoid process is made up of two parts, a vertical branch and a horizontal branch oriented from back to front from the inside to the outside. At the end of thisprocess the biceps brevis and the coraco-brachialis are inserted by a commontendon. On the internal face of this branch is inserted the small pectoral. . ● The glenoid labrum is made up of a fibro-cartilaginous ring placed on the around the glenoid cavity of the scapula. It is a triangular cartilage with three faces (peripheral,articular and bony). In its upper part the rim is only joined to the edge of the glenoidcavity, its internal, free face is only applied to the glenoid cartilage, and therefore hasthe characteristics of a meniscus. The function of the glenoid labrum is to increasethe depth of the cavity. It is a stabilizer of the glenohumeral joint. ➢ Clavicle The clavicle extends from the acromion to the sternum. Its stability is ensured by theacromioclavicular and sternoclavicular joints, but also by the trapezoid, conoid andcoracoclavicular ligaments. The clavicle serves as a fulcrum for many muscles; to thetrapezius, deltoid, pectoralis major and sternocleidomastoid on its upper surface, to thesubclavius and sternocleidomastoid on its lower surface.
➢ Sternum The sternum is made up of three odd and symmetrical pieces of bone which only participatein the shoulder girdle at the level of the sternoclavicular joint. The sternum as we know ittoday is the result of the fusion of independent bony parts, the sternebrae. The manubriumarticulates with the first rib and the clavicle superiorly, the second rib at its junction with thesternal body. The body, flat and elongated, has sixternal notches on each side. The joint ofthe manubrium and the body form a dihedral angle projecting anteriorly. The xiphoid joint isoften cartilaginous. On its anterior surface the manubrium and the body give insertion to thesternocleidomastoid muscles and the pectoralis major. ➢ Humeral head The upper end of the humerus presents, in addition to the head of the humerus (joint area),two tuberosities separated by the anatomical neck. The greater tuberosity is located outsidethe head on the 2 extension of the outer edge of the bone, while the trochin is positioned onthe anterior surface of the humerus. These two tuberosities are separated by anosteo-fibrous groove in which the tendon of the long biceps slides. The greater tuberositypresents on its upper and posterior surface three facets which give respectively insertion tothe supraspinatus, infraspinatus and teres minor muscles. The subscapularis muscle isinserted on the trochin. The banks of the bicipital groove provide insertion on the externalside to the pectoralis major and on the internal side to the teres major and latissimus dorsi.