22 MANUAL FOR STABLE SERGEANTS. 



(e) The deep digital fiexor (deep flexor of the foot) (fig. 6). Thia 

 muscle originates with the superficial digital flexor. Its tendinoua 

 portion begins at the knee, passes down the leg between the cannon 

 bone and the tendon of the superficial flexor, over the back part of 

 the fetlock, through the ring formed by the superficial tendon, and 

 is attached to the under surface of the third -phalanx. 



Action. — 1^0 flex the knee and all joints below it. 



26. Muscles of the hind limb (fig. 7). 



(a) The long digital extensor (long extensor of the foot) (fig. 7). 

 This muscle originates from the lower and front part of the femur; 

 its fleshy portion passes downward along the front surface of the 

 tibia to the hock, where it becomes tendinous; from the hock it 

 passes down the front of the leg to become attached to the upper 

 and front part of the third phalanx. 



Action. — To extend the foot and flex the hock. 



(6) Tibialis anterior (anterior tibial). This muscle lies in front of 

 the tibia. 



Origin. — From the front and outer border of the tibia. 



Insertion. — By two tendons, one to the upper and front part of 

 the large metatarsal bone; the other to one of the small bones on the 

 inner side of the hock. 



Action. — To flex the hock joint. 



(c) Peroneus tertius. — This is a strong tendinous cord, extending 

 from the lower end of the front part of th.^ femur to the hock where 

 it terminates in two branches — a large one inserted in the front part 

 of the upper end of the large metatarsal bone, and a small one passing 

 outward to become attached to one of the small bones of the hock. 



Action. — Mechanically to flex the hock when the stifle joint is 

 flexed. 



(d) The superficial digital flexor (superficial flexor of the foot) 

 (fig. 7) of the hind log originates at the back and lower part of the 



femur. It extends do^vnward back of the tibia to the point of the 

 hock over which it passes; thence down the back of the log to be dis- 

 posed of in the same manner as the superficial digital flexor of the 

 front leg. 



Action.' — To extend the hock and flex the fetlock and pastern. 



(e) The deep digital flexor (deep flexor of the foot) (fig. 7) of the 

 hind leg originates from the upper and back part of the tibia, near 

 the lower third of which it becomes tendinous and passes downward 

 over the inner and back side of the hock to become attached to the 

 third phalanx in the same manner as the deep flexor of the fore leg. 



Action. — To extend the hock and flex the joints below it. 



