THE REGION OF THE ELBOW 45 



through abrasions of the skin, after falls on the elbow. This 

 may cause cellulitis in the forearm from direct spread. Chronic 

 inflammation of this bursa is not uncommon in miners. 



The Head of the Radius can be felt on the posterior aspect 

 of the limb. When the forearm is flexed, it lies nearly an inch 

 in front of the lateral epicondyle, the interval between the two 

 being occupied by the capitulum (capitellum) of the humerus. 

 When the forearm is fully extended, the tip of the finger may 

 be inserted into a distinct hollow immediately proximal to the 

 head and behind the radial collateral (external) ligament. This 

 hollow corresponds to the lateral and posterior part of the 

 radio - humeral joint, and immediately proximal to it the 

 subcutaneous posterior aspect of the lateral epicondyle can be 

 made out. If the elbow is grasped by the hand so that the 

 olecranon fits into the palm, while the thumb rests over the 

 head of the radius, the latter will be felt to rotate when the 

 forearm is alternately pronated and supinated. 



Muscular Landmarks. The flexor muscles on the medial 

 side, and the extensor and supinator muscles on the lateral side, 

 bound the cubital fossa, a triangular depression in front of the 

 elbow, distal to the intercondylar line. Entering the fossa is 

 the strong tendon of the biceps, and the examining finger can 

 readily slip into the depression between this tendon and the 

 brachio-radialis. From the medial border of the tendon the 

 lacertus fibrosus (bicipital fascia) passes distally and medially 

 to blend with the fascia covering the flexor muscles. It hinders 

 the examination of the depression between the biceps tendon 

 and the flexor muscles, but if the finger is inserted behind its 

 prominent proximal border, the pulsations of the brachial artery 

 can readily be felt. 



Superficial Nerves of the Arm, Elbow Eegion, and 

 Forearm. The proximal part of the lateral aspect of the arm 

 is supplied by the Axillary (Circumflex) Nerve (C. 5 and 6). Be- 

 tween this area and the lateral epicondyle the skin is supplied 

 by the proximal division of the Dorsal Cutaneous Nerve of the 

 Forearm (Upper External Cutaneous Branch of Musculo-SpiraJ) 

 (C. 5 and 6), which arises just before the radial (musculo-spiral) 

 nerve penetrates the lateral intermuscular septum. It at once 

 pierces the deep fascia and associates itself with the cephalic 

 vein. The Distal Division of the Dorsal Cutaneous Nerve of the 

 Forearm (Lower External Cutaneous Branch of Musculo-SpiraT) 

 (C. 6 and 7), arises just distal to the last-named, runs distally 



