MYOLOGY. 69 



Actio7i. — Extends forearm. 

 Nerve. — Radial. 



LARGE EXTENSOR OF FOREARM. 



Origin. — Dorsal angle and axillary border of scapula. 

 Insertiofi. — Into olecranon, after gliding over a bursa. 

 Aciion. — As preceding. 

 Nerve. — Radial. 



SHORT EXTENSOR OF FOREARM. 



Origin. — Line runiiing from head of humerus to deltoid. 

 Insertion. — Imprint with preceding. 

 Action. — With preceding. 

 Nerve. — Radial. 



MIDDLE EXTENSOR OF FOREARM. 



Origin. — Inner surface of humerus above tuberosity. 

 Insertion. — Tip and side of olecranon. 

 Action. — As preceding. 

 Nerve. — Radial. 



ANCONEUS. 



Origin. — Above margin of olecranian fossa. 

 In^ertio7i. — Anterior and external border of olecranon. 

 Action. — Raises capsule of humero-ulnar-radial articulation. 

 Nerve. — Radial. 



FOREARM. 



The anti-brachial aponeurosis is a strong layer of fibrous tissue 

 that binds the muscles of the forearm together and passes be- 

 tween them, forming the inter-muscular septum. It is attached 

 to the olecranon and sides of radius. 



ANTERIOR EXTENSOR OF THE METACARPUS. 



Origin. — From humerus below crest of furrow of torsion, and 

 above and in front of the inferior articular portion. 



Insertion. — Anterior and superior tuberosity of large meta- 

 carpal bone. 



Action. — As name implies. 



Nerve. — Radial. 



