142 MUSCULAR SYSTEM. 



Its tendon is slender and flattened, arising about midway down 

 the arm, crosses just above the knee within a sheath to the inner 

 side, and at its termination expands and becomes confounded 

 with the general fibrous covering of the knee joint. 



Action. — To maintain the tendon of the extensor metacarpi in 

 its place during action : it will also have some effect in extending 

 the leg. 



SUPERFICIAL POSTERIOR BRACHIO-CRURAL REGION. 

 EPiTROCHLO-CARPEus. — Fkxov metacavpi externus. 



Situation. — Postero-external side of the arm. 



Form. — Elongated ; and flattened from without inward. 



Attachment. — Superiorly, to the postero-inferior part of the 

 external condyle : inferiorly (by one division of its tendon) to the 

 OS trapezium ; (by the other) to the head of the outer small me- 

 tacarpal bone. 



J{e/o/w?/s. — Externally, with aponeurosis and skin; internally, 

 with the flexor perforans : postero-internally, with the flexor ac- 

 cessorius sublimis, and next muscle ; antero-externally, with the 

 flexor accessorius profundus. 



Structure. — The superior attachment is mostly tendinous. The 

 surfaces are partially aponeurotic. The fleshy belly has two 

 wide tendinous intersections uniting below the middle of the 

 arm to form a broad, flat, thick tendon, which at the knee bifur- 

 cates into a broad flattened division, and a long narrow round 

 one : the latter is continued down at the back of the knee, in 

 contact with the capsular ligament, enveloped within a tendinous 

 sheath. 



Action. — To bend the leg. 



EPicoNDYLO-cARPEUs. — Flexov metacarpi medius. 



Situation. — Posterior part of the arm. 



Form. — Elongated ; flattened. 



Attachment. — Superiorly, to the external condyle of the hume- 

 rus ; also to the olecranon : inferiorly, to the trapezium. 



Relations. — Posteriorly, with the faschia and skin ; anteriorly, 

 with the flexor perforans : externally, with the preceding nmscle 

 and flexor accessorius sublimis ; internally, with the following 

 muscle. 



Structure. — Superior attachment, tendinous; surfaces par- 

 tially aponeurotic. Its belly has a single broad tendinous inter- 

 section, which terminates below in a thick flattened tendon, having 

 its under surface thinly covered with fleshy fibres. The part 

 attached to the olecranon is but a narrow thin fleshy slip. 



Action, — To bend the leg. 



