Shoulder joint

The humerus, artculatio humeri, is formed by the articular cavity of the scapula, caviias gtenoidalis scapulae, and the head of the humerus, caput humeri. The articular surfaces are covered with hyaline cartilage and do not correspond to each other. The congruence of articular surfaces increases due to the joint lip, labrum glenoidale, which is located at the edge of the articular cavity.

The joint capsule is fixed on the scapula along the edge of the articular cartilage of the articular cavity and along the outer edge of the joint lip; On the humerus, the joint capsule is attached to the anatomical neck. The joint capsule is spacious and slightly stretched. In the lower medial part, it is thin, and for the rest of its length the fibrous layer is supported by the muscle tendons that weave into it; In the upper and posterior and lateral sections - supraspinous, subacute and small round muscles, mm. Supraspinatus, infraspinatus teres minor, in the medial - subscapular muscle, m. Subscapularis. When moving in the shoulder joint, these muscles pull the articular capsule and do not allow it to be infringed between the articular surfaces of the bones, the joint capsule on the humerus bone in the form of a bridge spreads over the intertubercular furrow, where the tendon of the long head of the biceps brachula originates from the suprarenal tubercle and the edge of the articular Lips, passes through the cavity of the shoulder joint and then goes in the inter-tubercle groove. In the cavity of the shoulder joint, the biceps tendon of the biceps muscle is covered by a synovial membrane that accompanies it in the interstitial sulcus 2-5 cm below the level of the anatomical neck, then wraps up and, following the tendon, passes into the synovial membrane of the joint capsule.
Thus, a double-walled protrusion of the synovial membrane is formed around the tendon of the biceps arm muscle in the intercammonial sulcus, which is called the inter-tubercular synovial vagina, vagina synovialis intertubercularis. The joint cavity is often communicated with the subculture bag of the scapula, bursa subtendinea m. Subscapularts, located at the root of the coracoid process.
On the inner surface of the joint capsule are three joint-brachial ligaments, ligg. Glenohumeralia. They are attached from one side to the anatomical neck of the humerus, on the other - to the joint lip of the scapula. The upper and middle ligaments are separated by the holes of the bag located under the subscapular muscle. Bundles strengthen the anterior surface of the capsule of the shoulder joint.
In addition, the shoulder joint has a powerful beak-brachial ligament, lig. Coracohumerale. It is a consolidation of the fibrous layer of the capsule, which extends from the outer edge of the coracoid process to the large tubercle of the humerus.

The previously beak-acromial ligament, lig. Coracoacromiale. Located above the shoulder joint and together with the acromion and the coracoid process of the scapula forms the arch of the shoulder. The arch of the shoulder protects the shoulder joint from above and brakes along with the tension of the joint capsule, the withdrawal of the shoulder and the raising of the arm forward or to the side of the shoulder level. Further movement of the final rn upwards is accomplished by the motion of the blade along with it.

Shoulder joint is triaxial, in shape refers to globular joints. Thanks to the fact that the shoulder joint is the most movable joint of the human body, the hand has considerable freedom of movement.