:!2G A Manned of Veterinary Physiology. 



of the leg and the flexing of the hock and stifle, is that the 

 foot is flexed. In a certain surgical condition, commonly 

 known as dislocation of the patella, the limb is rigid from 

 the stifle to the hock ; but, though the foot may be flexed, 

 neither hock nor stifle responds, owing to the patella being 

 fixed. I believe, in the majority of these cases, that the 

 patella is not fixed from dislocation but from spasm of the 

 patella muscles. 



The amount of movement in the stifle is so considerable, 

 that to admit of it being carried out with perfect freedom 

 the convex condyles of the femur play in cups formed of 

 cartilage on the upper surface of the tibia. It will be 

 noticed that the patella does not play up and down on the 

 femur, as at first sight we might expect, but rather that 

 the femur plays on the patella by the opening and closing 

 of the femoro-tibial angle. 



The Hip is a cup and ball joint ; the range of movement 

 obtained by it in the horse is limited by the insertion of 

 the ligamentum teres and pubio-femoral ligament into the 

 inner side of the head of the femur, and not into its centre 

 as in most other animals. This is said to be the reason 

 why the horse rarely ' cow-kicks.' The lengthening of 

 these ligaments, according to my unpublished observations, 

 accounts for ' cow-hocks ' in horses. 



The Shoulder-joint is remarkable for the considerable 

 surface afforded by the humerus and the small surface of 

 the scapula, the object being to obtain a large range of 

 motion. 



The Elbow presents an articulation with ridges which 

 influence the turning outwards of the knee in progression ; 

 if the knees are turned out too much the leg below is 

 thrown in as it is brought forward, and in this way ' brush- 

 ing ' and ' speedy cutting ' is produced : but in the knee- 

 joint a provision exists to counteract this movement. 



The Knee consists of three main joints ami numerous 

 minor ones ; the upper joint possesses the largest range of 

 motion, whilst the lower joint, practically dors not open 1 . 

 Probably such defects as speedy cutting and its opposite 



