Fascia of shoulder and upper arm

The superficial fascia of the upper limb is part of the superficial fascia that covers the entire body.

The fascia of the supraspinatus is thick (up to 2 mm), dense, at the top it is fused with the transverse ligament of the scapula, with the coracoid process and the capsule of the shoulder joint. Between the nadostnoy muscle and the bottom of the dystrophic fossa there is a thin layer of fiber, in which the suprascapular nerve and the suprapular artery with adjacent veins are located.

Subacute fascia is also dense, has a tendon structure. This fascia forms a fascial box for a small round muscle, and also extends to a large round muscle. In loose fiber under the subaccess muscle there is an artery, enveloping the scapula. At the base of the acromial process, the supraspinous and subacute fascial cases communicate with each other (along the course of the blood vessels and nerves passing through the subacute fossa).

In the deltoid region, the superficial fascia has a fibrous structure, especially over the acromial part of the deltoid muscle.

The delta-shaped fascia (fascia deltoidea) forms a fascial box for the deltoid muscle. From this fascia, the connective tissue septa move into the muscle, especially at the boundaries of the scapular, acromial and clavicular parts. From the partitions begins a part of the fibers of the deltoid muscle. The counterfeit cellular space corresponding mainly to the acromial part of the muscle extends downward to the place where the deltoid muscle is attached to the humerus. In the counterfeit space, the tendon of the long head of the biceps arm muscle, the axillary nerve branch and the posterior artery circumscribing the humerus are located, which penetrate the counterfeit space through the quadruple orifice. In the counterfeit space, the anterior artery and the vein that surround the humerus also pass. The deltoid fascia laterally and downwards continues into the fascia of the shoulder, in front - to the fascia of the chest, behind fuses with the subacute fascia.

Axillary fascia (fiscia axillaris) thin, loose, has numerous holes through which the skin nerves, blood and lymph vessels pass. At the borders of the axillary region, the fascia thickens and fuses with the fasciae of neighboring regions - passes into the fascia of the breast and the fascia of the shoulder.

Fascia brachialis (fascia brachialis) forms two osteo-fascial beds (anterior and posterior), which are separated from each other by the medial and lateral intermuscular septum (septum intermusculare brachii mediale et septum intermusculare brachii laterale). These septa extend from the fascia of the shoulder and attach to the humerus. In the anterior bone-fascial bed, the muscles are arranged in two layers. The biceps arm muscle is more superficially located, and under it lie the beak-brachial (proximal) and brachial (distal) muscles. Both layers of muscles are separated by a deep leaf of the fascia of the shoulder, under which passes the musculocutaneous nerve.

In the medial groove of the biceps brachii of the shoulder, there is a vascular-neural bundle formed by the median nerve, the brachial artery and veins. On the posterior surface of the shoulder, its own fascia forms the vagina of the triceps arm muscle, in front of which the posterior neurovascular bundle passes in the radial nerve channel. The canal of the radial nerve or cannabis canalis nervi radialis, s. Canalis humeromuscularis, is located between the posterior surface of the humerus and the triceps muscle. The upper (inlet) opening of the canal, located at the level between the upper and middle third of the body of the humerus, is bounded from the medial side by the humerus and the two heads (lateral and medial) of the triceps arm muscle. The lower (outlet) opening of the canal is located at the level of the boundary between the middle and lower thirds of the humerus on the lateral side of the shoulder, between the brachial and brachial muscles. In this channel, the radial nerve passes along with the deep artery and the veins of the shoulder.

In the back of the ulnar region, on the sides of the elbow process, two furrows are visible. Above the elbow itself under the skin is located subcutaneous ulnar mucous bag. Under the tendon of the triceps muscle, the shoulder, attached to the upper-posterior surface of the elbow, is located the epithelium of the same name . On the back surface of the elbow joint, the fascia is thickened due to the tendon fibers of the triceps brachii that weave into it. The fascia is firmly fused with the posterior edge of the ulna, as well as with the medial and lateral epicondyle of the humerus. Under the fascia, in the posterior medial ulnar fissure, in the osteo-fibrous canal (narrow slit) formed by the posterior surface of the medial epicondyle of the humerus, the elbow process and fascia, the elbow nerve passes.

In the anterior elbow region, the ulnar fossa (fossa cubitalis) is visible, the bottom and upper border of which is limited by the brachial muscle (from the lateral side) and the round pronator (from the medial side). In the ulnar fossa, the lateral ulnar fissure (sulcus bicipitalis lateralis, s. Radialis) is delimited from the outside by the humerus muscle, on the medial side by the brachial muscle, and the medial ulnar groove (sulcus bicipitalis medialis, s. Ulnaris) located between the circular pronator (laterally) and the brachial muscle (medially). In the subcutaneous tissue there are lateral and medial subcutaneous veins. Under the aponeurosis of the biceps arm muscle passes the brachial artery, to which are adjoined two eponymous veins and the median nerve. In the anterior elbow region, above the tendon of the biceps arm muscle, the fascia is thin. Medial to this tendon, the fascia thickens, as it is reinforced by the fibers of the aponeurosis of the biceps arm muscle.

The medial and lateral intermuscular septa extend along the lines of the medial and lateral ulnar fissures from the fascia, which attach to the epicondyle of the humerus and to the capsule of the elbow joint. As a result, in the anterior elbow region under the fascia, 3 fascial muscle beds (a box) are formed. In the medial bed, the most superficially lie the round pronator, the radial flexor of the wrist, the long palmar muscle and the ulnar flexor of the wrist. Under these muscles, the superficial flexor of the fingers is located in the second layer, in the lateral fascial bed there is the brachial muscle, and below it the supinator. On the average fascial bed (between two ulnar furrows), the distal part of the biceps muscle of the shoulder and its tendon are located, and below it is the elbow muscle. Between these muscle groups in the clefts of the muscle septum pass the medial and lateral vascular-neural bundles on the forearm. Distal to the elbow joint, the medial and lateral fascial intermuscular septums converge and join together, forming an anterior radial intermuscular septum of the forearm.

[1], [2]