250 



MYOLOGY. 



Action. — To flex the fetlock and pastern joints, and assist iit 

 extending the tarsus ; when the animal 

 is stationary, it serves mechanically, a* 

 a fibrous band, to prevent flexion of 

 the tarsal joint. 



FLEXOR Pm)IS PERFOBANS. 



( Tibio-phalangeua. ) 



(Fig. 86. c.) 



Situated on the posterior aspect of 

 the leg, extending from the head of 

 the tibia to the distal phalanx, this 

 muscle is thick and prismatic, consist- 

 ing of a fleshy, intersected belly and 

 long tendon of insertion. The belly is 

 partially bifid, the internal portion 

 being the larger. The tendon com- 

 mences a little above the hock, passes 

 through the groove on the inner side 

 of the calcaneum, first crossing the 

 posterior capsular ligament of the 

 tarsus, where it is bound down by 

 fibrous tissue, in a synovial sheath, the 

 usual seat of Thorough-pin. It then 

 descends behind the metatarsal bone ; 

 about half-way down, it is joined by 

 the check ligament, which springs from 

 the lower bones of the tarsus and head 

 of the metatarsal bone, and is similar 

 to, but considerably less than, that of 

 the fore extremity. It is joined above 

 by the tendon of the flexor accessorius, 

 and is otherwise disposed exactly as 

 the perforans tendon of the anterior 

 extremity. 



Origin. — From the roughened pos- 

 terior aspect, and head of the tibia, the 

 fibula, and fibulo-tibial ligament. 



Insertion. — To the semilunar ridge 

 on the solar surface of the os pedis. 



FiQ. 86. 

 Posterior tibial group of muscles 

 of the right limb— postero-internal 

 view. The gastrocnemius is removed. 

 a, Popliteus; 6, Flexor pedio per- 

 foratus; t'. Its tendon; 6", Expansion 

 of its tendon forming the cap of the 

 hock; c, Flexor pedis perforans; c', 

 Its tendon ; d, Floxor accessorius, d', 

 Union of its tendon with that of the 

 perforans. 



