LIGAMENTS OF THE SCAPULA. 



287 



cess, internal to the preceding; above, by its expanded base, to the conoid 

 tubercle on the under surface of the clavicle, and to a line proceeding inter- 

 Fig. 198. The Left Shoulder-Joint, Scapulo-clavicular Articulations and Proper Ligaments 



of Scapula. 



nally from it for half an inch. These ligaments are in relation, in front, with 

 the Subclavius ; behind, with the Trapezius : they serve to limit rotation of the 

 scapula forwards and backwards. 



The Interarticular Fibro-cartilage is most frequently absent in this articula- 

 tion. When it exists, it generally only partially separates the articular sur- 

 faces, and occupies the upper part of the articulation. More rarely, it com- 

 pletely separates the joint into two cavities. 



There are two Synovial Membranes when a complete interarticular cartilage 

 exists ; more frequently there is only one synovial membrane. 



Actions. The movements of this articulation are of two kinds. 1. A gliding 

 motion of the articular end of the clavicle on the acromion. 2. Rotation of 

 the scapula forwards and backwards upon the clavicle, the extent of this rota- 

 tion being limited by the two portions of the coraco-clavicular ligament. 



III. PROPER LIGAMENTS OF THE SCAPULA. (Fio. 198.) 

 The proper ligaments of the scapula are, the 



Coraco-acromial. Transverse. 



The Coraco-acromial Ligament is a broad, thin,. flat band, of a triangular shape, 

 extended transversely above the upper part of -the shoulder-joint, between the 

 coracoid and acromion processes. It is attached, by its apex, to the summit of 

 the acromion just in front of the articular surface for the clavicle; and by its 

 broad base, to the whole length of the outer border of the .coracoid process. 



