THE FRONT OF THE ARM 



95 



nearer to the medial than to the lateral epicondyle. The 

 loose skin which covers the olecranon moves freely over its 

 subcutaneous surface, owing to the interposition of a bursa. 

 The different positions which are assumed by the olecranon, 

 in relation to the epicondyles of the humerus in the move- 

 ments of the forearm at the elbow-joint, must be carefully 

 examined. That can be done best by placing the thumb on 

 one epicondyle, the middle finger on the other, and the fore- 



FIG. 39. Relation of Bones 

 of Elbow to the surface. 

 Dorsal view ; elbow fully 

 extended. 



FIG. 40. Relation of the 

 Bones of the Elbow to the 

 surface. Dorsal view ; 

 elbow bent. 



finger on the olecranon. The limb should then be alternately 

 flexed and extended, so as to make clear the extent of the 

 excursion performed by the olecranon. In full extension 

 at the elbow -joint the three prominences lie in the same 

 horizontal plane ; when the forearm is bent at a right angle 

 the three bony points are placed at the angles of an equilateral 

 triangle, of which one angle points distally. 



When the forearm is extended a marked depression on the 

 dorsal aspect of the elbow indicates the position of the articula- 



