Translations:Schulterblatt/4/en

The Angulus acromii is an easily palpable bone point that marks the point where the lateral edge of the Acromion merges into the Spina scapulae. The lateral angulus is the location of the acetabulum, the cavitas glenoidalis (11). At its upper margin a small hump is visible, the Tuberculum supraglenoidale (12). Below the Cavitas is the Tuberculum infraglenoidale (13). After cavitas glenoidalis the neck of the scapula lies, collum scapulae.
Above the Cavitas glenoidalis rises the raven beak process, Processus coracoideus (14). It bends at right angles to lateroventral and ends flattened. Together with the acromion it protects the underlying joint. Medial from the base of processus coracoideus is found in margo superior an incision, incisura scapulae (15).
The bony socket Cavitas glenoidalis (11) of the Articulatio humeri, a ball joint, is considerably smaller than the head of the humerus. The socket is enlarged by a fibrous cartilaginous joint lip, Labrum glenoidale. The surface of the Cavitas glenoidalis is approx. 6qcm. The weight of the upper extremity is about 4 kg. Since there are no stronger ligaments, the muscles surrounding the joint must secure it. This is why we speak of a muscle-secured joint. The so-called "rotator cuff" is part of this muscular securing and especially strengthens the joint capsule.