Muscles of the shoulder
Last reviewed: 23.04.2024
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The muscles of the shoulder are divided into two groups according to the topographic and anatomical principle: the anterior (flexor) and the posterior (extensors). The anterior group consists of three muscles: the coracoid-brachial, the biceps arm muscle and the brachial muscle; the back is the triceps brachii muscle and the elbow muscle. These two groups of muscles are separated from each other by plates of the fascia of the shoulder: from the medial side - by the medial intermuscular septum of the shoulder, with the lateral - by the lateral intermuscular septum of the shoulder.
Anterior muscle group of the shoulder
The biliary-brachial muscle (m.coracobrachialis) begins at the apex of the coracoid scapula of the scapula, passes into a flat tendon that attaches to the humerus below the crest of the small tubercle at the level of the tendon attachment of the deltoid muscle. Part of the muscle bundles is interlaced in the medial intermuscular septum of the shoulder.
The biceps arm muscle (m.biceps brachii) has two heads - short and long.
A short head (caput breve) begins with the coracoid-brachial muscle at the apex of the coracoid process of the scapula. The long head (caput longum) originates on the supraarticular tubercle of the scapula with a long tendon that perforates the capsule of the shoulder joint from above (being covered in the joint cavity by the synovial membrane) and exits to the shoulder, where it lies in the intertubercular furrow.
The biceps arm (shoulder biceps)
The brachial muscle (m.brachialis) begins on the lower two thirds of the humerus body between the deltoid tuberosity and the joint joint capsule of the elbow joint, on the medial and lateral intermuscular septum of the shoulder. It is attached to the tuberosity of the ulna. The bundles of the deep part of the tendon of this muscle are weaved into the capsule of the elbow joint.
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Back muscle group of the shoulder
The triceps brachii muscle (m.triceps brachii) is thick, occupies the entire posterior surface of the shoulder, has three heads. The lateral and medial heads begin on the humerus, and the long ones on the shoulder blade.
The lateral head (caput laterale) begins with tendon and muscle tufts on the outer surface of the humerus, between the place of attachment of the small round muscle - proximally and the furrow of the radial nerve - distally, and also on the posterior surface of the lateral intermuscular septum. The bunches of the lateral head pass downward and medially, covering the furrow of the radial nerve with the nerve of the same name and the deep vessels of the shoulder.
The triceps brachialis muscle (triceps pecula)
The ulnar muscle (m.anconeus) is triangular in shape, starting at the posterior surface of the lateral shoulder oath; is attached to the lateral surface of the elbow, the posterior surface of the proximal ulna and to the fascia of the forearm.