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The subscapular muscle is divided into two portions: a superior, 

 small, triangular, passes from the thoracic aspect of the coracoid bone, 

 and upper part of the scapula, to be inserted into the inner tubercle, at 

 the upper extremity of the humerus. The inferior portion arises from 

 the posterior border of the scapula ; the fibres run outwards, to be in- 

 serted by a twisted tendon below the last. 



Deltoid — a triangular muscle — arises from the posterior border of 

 the scapula, behind the humeral joint, by a flat tendon; it passes down- 

 wards and outwards, becoming fleshy, and is inserted into the ridge on 

 the back of the humerus, as far down as to within three inches of the 

 humero-cubital articulation. 



Teres minor passes from the border of the blade of the scapula to 

 the lowest point of the tubercle of the humerus. Extensor cubiti con- 

 sists of two heads — one long, arising from the lower border of the sca- 

 pula, between teres and deltoid ; the second, or inner, from a ridge on 

 the inner side of the humerus, as far down as an inch from the cubital 

 joint ; the two heads unite low down, and clothe the back of the hu- 

 merus, and are inserted into the olecranon process of the ulna and fascia. 

 Brachialis anticus arises from the lower half of the anterior surface of 

 the humerus, passes under the pronator teres, to be inserted into an 

 oblique ridge on the front of the ulna. Pronator teres runs from the 

 internal condyle to the outer side of the radius, and passes over the 

 radial artery. 



Flexor digitorum communis arises from the anterior surface of the 

 ulna, as far down as the lower extremity of that bone. The fibres end 

 in small tendons, which are inserted into the second phalanx of all the 

 digits. 



Flexor carpi ulnaris passes from the inner condyle of the humerus, 

 and the external part of the ulna, to the pisiform bone of the carpus. 

 Supinator longus arises from a ridge above the outer condyle, and is in- 

 serted into the metacarpal bone of the thumb. The musculo-spiral 

 nerve runs between this muscle and the brachialis anticus. Supinator 

 brevis, beneath the last, runs from the outer condyle and external la- 

 teral ligament, to be inserted into the upper and outer part of the 

 radius. 



Extensor carpi radialis arises from the posterior surface of the 

 radius, and runs to be inserted into the outer metacarpal bone. 



Extensor digitorum communis passes from the external condyle into 

 the last phalanges of the inner digits. 



Extensor carpi "ulnaris arises from the back of the outer condyle, 

 and from the posterior surface of the ulna, for its whole length, and is 

 inserted into the base of the outer metacarpal bone. 



Indicator passes from the interosseous space, and the side of the ulna, 

 and ends in a tendon which passes to the index finger. There are two 

 interossei on the front of the metacarpal bones, and one on the dorsal 

 aspect. A small abductor minimi digiti runs from the pisiform bone to 

 the metacarpal bone of the third finger ; and a still smaller abductor 

 pollicis is attached to the outer bones of the carpus, and inserted into 



