ARTICULATIONS 



149 



Biceps 

 brachii 



Brachial 



The articular capsule is attached proximally to the antero- 

 medial and antero-lateral surfaces of the humerus, above the 

 coronoid and radial fossae respectively. At the sides it is 

 attached to the epicondyles and posteriorly to the posterior sur- 

 face on which the line of attachment passes through the upper 

 part of the fossa olecrani. Distally the capsule is attached 

 to the anterior margin of the proximal, medial, and lateral 

 surfaces of the olecranon ; to the medial and volar margins 

 of the coronoid process of the ulna, and to the annular 

 ligament of the radius. The anterior part of the capsule 

 consists of fibres which 

 take an irregular 

 course over the an- 

 terior aspect of the 

 joint. The posterior 

 part of the capsule is 

 weaker than the an- 

 terior and its attach- 

 ment to the posterior 

 surface of the humerus 

 is comparatively 

 loose. 



Ligamentum Col- 

 lateraleRadiale(O.T. 



External Lateral Ligament). This is a strong but short 

 ligamentous band which is attached above to the distal aspect 

 of the lateral epicondyle of the humerus. Below, it is fixed 

 to the annular ligament of the radius, and also, more posteriorly, 

 to the lateral side of the olecranon of the ulna. The annular 

 ligament is a strong ligamentous collar which surrounds the 

 head of the radius, and retains it in the incisura radialis of 

 the ulna. 



Ligamentum Collaterale Ulnare (O.T. Internal Lateral 

 Ligament). The ulnar collateral ligament, taken as a whole, 

 is fan-shaped. By its proximal pointed part it is attached to 

 the medial epicondyle of the humerus. Distally it spreads 

 out to find insertion into the coronoid process and olecranon. 

 It consists of three very distinct portions, viz. an anterior, a 

 posterior, and a transverse. 



The anterior part springs from the distal and anterior part of 

 the medial epicondyle, and is attached to the medial margin 

 of the coronoid process of the ulna. The posterior part is 



Flexor carpi 

 ulnaris 



FIG. 58. Vertical section through Humerus 

 and Ulna at the Elbow-joint. 



