266 THE MUSCLES. 



of the opiaoiidjdc by a very powerful, but extremely short tendon. In-_^ 

 feriorly, it terminates by a second tendon longer than the preceding, and" 

 divides into two branches, an anterior and a posterior. The latter (Fig. 119, 

 20), short and wide, is inserted into the supercarpal bone in becoming mixed 

 up with the oblique flexor. The former (Fig. 1 19, 19), rounded and funicular 

 in shape, glides by means of a synovial bursa in the channel excavated on 

 the external aspect of the supercarpal bone, and which is converted into 

 a canal by a little fibrous apparatus ; this branch is afterwards fixed on the 

 head of the external metacarpal bone by being confounded with the external 

 ligament of the carpus. 



Relations. — Covered by the antibracbial aponeurosis, this muscle covers 

 the two flexors of the digit. Its anterior border responds to the lateral 

 extensor of the phalanges ; the posterior to the oblique flexor. Its superior 

 tendon lies behind the external ligament of the elbow joint, and is covered 

 deeply by the external cul-de-sac of the synovial capsule belonging to that 

 articulation. 



Action. — It flexes the foot on the fore-arm. (Leyh observes that it is 

 more particularly concerned in what is known as " high action.") 



2. Oblique Flexor of the Metacarpus, or Anterior Ulnaris. (Fig. 121, 19.) 



Synonyms. — Epitrochlea supercarpeus — Girard. {Flexor metacarpi medius — PercivaU, 

 Eumero-metacarpeus internus — Leyh.') 



Situation — Form — Structure. — This muscle, situated behind and within 

 the fore-arm, is an exact counterpart of the preceding in form and structure. 



Direction. — Bourgelat has improperly named it an oblique flexor, for its 

 direction is vertical like that of the other muscles of this region. 



Attachments. — It has its origin : 1, On the base of the epi treghl on. by the?" 

 tendinous fibres of its superior extremity ; 2, On the olecranon, by a small,"^ 

 veiy thin, and very pale fleshy band, which is annexed to the principal 

 muscular body, and soon unites with its posterior border. Its inferior tendon 

 is undivided, and terminates on the supercarpal bone, along with the ex- 

 ternal flexor, to which it is intimately attached. 



Belations. — By its superficial face, with the antibracbial aponeurosis, 

 which strongly adheres to its tendon ; by its deep face, with the flexors of 

 the phalanges. Its anterior border is covered by the internal flexor ; the 

 posterior responds to the external flexor. 



Action. — ^It is a congener of the preceding. 



3. Internal Flexor of the Metacarpus, or Palmaris Magnus. (Fig. 121, 19.) 



Synonyms.— 'Epitrochlea, metucaTpeua— Girard. (Flexor metacarpi internus — Perci- 

 vaU. Humero-metacarpeus internus — Leyh.) 



Situation — Form— Structure — Attachments. — This muscle is situated 

 within the fore-arm, against the posterior face of the radius, and in its 

 general features resembles its congeners, the two preceding muscles. It is, 

 however, not so wide, is thinner, and less aponeurotic. Its upper extremity 

 is fixed, by tendinous fibres, to the base of the GpHndAftrat the same point V^ 

 as the oblique flexor, with which it is confounded— ori^ira. Its inferior - 

 extremity terminates in a long, thin, funicular tendon which passes through 

 a fibrous sheath at the inner side of the knee, and is inserted into the head 

 of the internal metacarpal bone — movable insertion. 



Belations. — It is covered by the antibracbial aponeurosis, and covers the 

 oblique flexor, the perforatus and perforans, as well as important blood- 



