THE PASTERN 79 



THE FETLOCK 



The fetlock-joint, with its anatomical i-ehition.s, constitutes an interest- 

 ing and important piece of animal mechanism. The bones entering into its 

 composition are shown in fig. 59, and consist of the inferior extremity of 

 the canon, articuhxting beh)w with the long pastern and behind with the 

 two sesamoid bones, the four together comltining to form a joint whose 

 movements, although confined to flexion and extension, are in these 

 directions of great range. 



The sesamoid bones are connected with the back part of the knee Ijy 

 means of the suspensory ligament (fig. 60), a powerful elastic band by 

 which the Ijones are supported in opposition to the downward and l)ack- 

 ward pressure imparted to them by the canon. While offering considerable 

 resistance to the descent of the fetlock-joint, the elasticity of the suspen- 

 sory ligament .still permits it to yield more or less in accordance with the 

 weight imposed upon it. The spring-like action thus imparted to the joint 

 is still further amplified by the flexor tendons, which, in descending the leg, 

 play over the sesamoid bones behind as does a rope over a pulley, and by 

 limiting the descent of the fetlock thereby prevent any undue strain on 

 the elasticity of the suspensory ligament. 



It will be seen, therefore, that besides supporting w^eight, the con- 

 struction of this joint is by its elastic mechanism specially adapted to the 

 important purpose of warding off concu.ssion. 



To be in other respects efficient, the fetlock-joint should be broad from 

 side to side and from front to back, thus j^roviding for a large surface of 

 articulation on the ends of the bones and greater leverage from the back- 

 ward projection of the sesamoid bones, which unite to render the range 

 of movement both free and extensive. 



THE PASTERN 



The pastern, which, as we have seen, assists to form the fetlock-joint, is 

 situated between it and the coronet. The points of special interest attach- 

 ing to this region are its length and its obliquity, in both of which excess or 

 deficiency will constitute a defect of conformation proportionate to its extent. 



The longer the pastern the more the reaction of the soil against the 

 weight of the body augments and fatigues the muscles and taxes the 

 tendons and ligaments which are connected with the sesamoid bones. 



Deficiency of length of the pastern evidently has inverse drawbacks. 

 The short-jointed horse surcharges his bones beyond measure. He lacks 

 suppleness in consequence of the insufficiency of the fetlock as an apparatus 



