CHAPTER IX. 



LAMENESS IN THE HIND-LEG. 



Anatomo-physiological Revie-w. 



The lunctions of tlie hind-leg, like those of the fore-leg, 

 may be divided into the swinging and supporting leg. The 

 supporting leg sustains the weight while the animal is at 

 rest, but during motion it is also concerned in the propulsion 

 of the body. The function of the supporting leg is executed 

 principally without the aid of muscles, it being equipped 

 with a check apparatus which fixes the joints. Under these 

 circumstances an expenditure of muscular energy becomes 

 at once unnecessary, provided the joints from the stifle down 

 are fixed, the ilium being immovable and sustained by the 

 head of the femur. The flexor metatarsi unites the stifle 

 aud hock joints, the gastrocuemii, the posterior face of the 

 femur and os calcis. As the flexor metatarsi is in front and 

 the gastrocuemii behind the axis of the stifle and hock joints, 

 the femur is connected with the metatarsus in such a 

 manner as to make the movements of these two joints 

 dependent on each other, — that is, if one is extended or 

 flexed the other undergoes the same movement at the same 

 time. The phalanges are fixed similarly as in the fore-leg 

 by the flexor tendons ; the check ligament of the perforaus 

 pulling the hock downward and backward, just as the carpus 

 is fixed in the fore-leg. While the check ligament just 



