MUSCLES OF THE RIGHT SUPERIOR LIMB 57 



and one or more on the volar side of the digits. This is best 

 accompKshed after the extensor communis digitorum (23) and 

 flexor sublimis (29) muscles have been transected so that their 

 tendons can be manipulated freely through the tendon sheaths. 

 Method: Remove the skin entirely from the hand and digits 

 including every hair. The best way to do this is to insert the 

 grooved director along the medial side of the carpus and pollex, 

 then cut through the skin mediad. Do the same thing on the 

 fifth digit and cut through the skin laterad; then carefully 

 dissect the skin off the back and volar sides of the hand. The 

 tendons of the extensor muscles of the hand lie just under 

 the skin, while those of the flexors are better protected. Clear 

 the remaining superficial fascia off of the back and volar sides 

 of the hand so as to expose the glistening tendons clearly. The 

 antibrachial fascia (homologue of crural fascia, p. 63) is a tough 

 sheet of tendonous tissue which envelops the antibrachium, 

 dipping between the muscles, especially on the extensor side. 

 It will have to be removed. 



23. Extensor communis digitorum m. : Lateral epicondyle 

 of humerus and adjacent region of ulna and other fascia; to all 

 digits except the pollex. Draws hand, especially the digits, 

 craniad. Method: After the back of the hand has been cleared 

 of superficial fascia so that the tendons and annular ligaments 

 are clearly visible pick up the tendons of this muscle just 

 proximad to the ligamentum carpi dorsale (Fig. 20, AL) with 

 the forceps and manipulate it, by flexing and extending the 

 hand, so as to demonstrate the insertion of the various tendons. 

 Transect, but be careful not to cut the next muscle (24) which 

 passes along the index tendon and under the belly of the 

 extensor digitorum communis m. (23). 



24. Extensor pollicis et indicis m.: Craniolateral region 

 of ulna near elbow joint; to pollex and index finger. Extensor 

 and abductor of pollex. Do not transect. This muscle 

 respresents and is sometimes separated to form the extensor 

 longus polhcis and extensor indicis mm. as in man. 



