REGION OF THE ELBOW. 



285 



attachment of both these sets of muscles coincides too closely with the axis of motion 

 to allow of their aiding to any marked extent either flexion or extension of the 

 elbow. Their function as far as the elbow is concerned is to aid and strengthen the 

 lateral ligaments of their special sides. 



The Anterior or Flexor Muscles. These Comprise the biceps, brachialis 

 anticus, brachioradialis, and extensor carpi radialis longior. It will be observed 

 that the first two muscles come from above and cross the joint, while the last two 

 arise just above the joint to pass down the forearm (Fig. 297). 



The brachialis anticus arises from the humerus by two heads, one on each 

 side of the insertion of the deltoid, and from the anterior surface to just above the 



Biceps 



Inner head of triceps 



Flexor carpi ulnaris- 



Brachialis anticus 



Brachioradialis 



Supinator 



Pronator radii teres 



Flexor carpi radialis 



Palmaris longus 



FIG. 297. View of the antecubital fossa and muscles at the bend of the elbow. 



elbow-joint. It passes over the joint and inserts into the base or lower and inner 

 part of the coronoid process. It does not insert into the tip, but some distance 

 below. Its function is purely flexion. 



The biceps arises from the upper rim of the glenoid cavity by its long head and 

 from the coracoid process by its short head. It inserts into the posterior edge of the 

 bicipital tubercle of the radius. Between it and the tubercle is a bursa. About 4 cm. 

 ( i % in. ) above its insertion its tendon gives off a fibrous expansion which passes 

 inward to blend with the deep fascia covering the flexor group of muscles. This is 

 called the bicipital or semilunar fascia. The biceps tendon passes almost in the 

 middle between the two condyles. Along its inner side is the brachial artery, which 

 is covered by the bicipital fascia; over this fascia passes the median basilic vein, 

 sometimes used for transfusion. The insertion of the biceps is into the radius, which 

 is the movable bone, and not into the ulna, which is less so. As a consequence, in 

 addition to its function of flexion it acts also as a powerful supinator of the radius. 



