a facial oie ag 
72 THE ARTICULATIONS OR JOINTS. 
iw) 
directions—obliquely, transversely, and vertically—and of these the vertical fibres 
are of most importance. It is attached above to the upper margins of the coronoid 
and supracapitellar fossze ; below, to the margins of the coronoid process and to the 
orbicular ligament of the superior radio-ulnar joint, but some loosely-arranged 
fibres reach as far as the neck of the radius. The lateral portions of this ligament, 
which are situated in front of the capitellum and inner margin of the trochlea 
respectively, are much thinner and weaker than the central part. Fibres of origin 
of the brachialis anticus muscle arise from the front of this ligament. 
The posterior ligament is an extremely thin, almost redundant layer. 
Superiorly it is attached, in relation to the margin of the olecranon fossa, at a 
varying distance from the trochlear articular surface, and inferiorly to the summit 
and sides of the lip of the olecranon process. Externally some of its fibres | 
pass from the posterior aspect of the capitellum to the posterior border of the lesser 
sigmoid cavity of the ulna. This ligament derives material support from, and . 
participates in the movements of, the triceps muscle, since they are closely — 
adherent to each other in the region of the olecranon process. 
The internal lateral ligament (lig. collaterale ulnare, Figs. 211 and 212) is a fan- 
Humerus 
Interosseous membrane Radius Coronoid process 
1 
Oblique ligament Tendon of biceps 
- Internal condyle 
Anterior part of internal 
lateral ligament 
Posterior part of 
internal lateral ligament 
Olecranon process 
Ulna Transverse part of internal lateral ligament 
Fic, 212.—ELBow-Jomnt (inner aspect). 
shaped structure of unequal thickness, but its margins, which are its strongest bands, 
are continuous with the adjoining parts of the anterior and posterior ligaments. 
By its upper end it is attached to the anterior, inferior, and posterior aspects of the 
internal condyle of the humerus. By its broad lower end it is attached to the 
inner margin of the greater sigmoid cavity, so that the anterior band is associated 
principally with the inner margin of the coronoid process, and the posterior band 
with the inner margin of the olecranon process, while the intermediate weaker 
portion sends its fibres downwards to join a transverse band, sometimes very strong, 
which bridges the notch between the adjoining inner margins of the coronoid and 
olecranon processes. . 
The external lateral ligament (lig. collaterale radiale, Fig. 211) is a strong 
flattened band attached superiorly to the lower and posterior aspects of the external 
condyle of the humerus. It completes the continuity of the capsule on the outer 
side, and blends inferiorly with the orbicular ligament, on the surface of which its 
fibres may be traced both to the anterior and posterior ends of the lesser sigmoid 
