8 



placed behind the pasterns and are called flexors, because they flex, or 

 bend, the pasterns and coffinbone backward. One of these tendons is 

 attached to the upper end of the short pastern, while the other passes 

 down between the heels, glides over the under surface of the navic- 

 ular bone, and attaches itself to the under surface of the coffinbone. 

 These two tendons not only flex, or fold up, the foot as the latter 

 leaves the ground, during motion, but at rest assist the suspensory 

 ligament in supporting the fetlock joint. 



Foot-axis. — The foot-axis is an imaginary line passing from the fet- 

 lock joint through the long axes of the two pasterns and coffinbone. 

 This imaginary line, which shows the direction of the pasterns and 

 coffinbone, should always be straight — that is, never broken, either 

 forward or backward when viewed from the side, or inward or out 

 ward when observed from in front. Viewed from one side, the long 

 axis of the long pastern, when prolonged to the ground, should be 

 parallel to the line of the toe. Viewed from in front, the long axis 

 of the long pastern, when prolonged to the ground, should cut the 

 hoof exactly at the middle of the toe. 



Raising the heels or shortening the toe not only tilts the coffinbone 

 forward and makes the hoof stand steeper at the toe, but slackens 

 the tendon that attaches to the under surface of the coffinbone, 

 and therefore allows the fetlock joint to sink downward and back- 

 ward and the long pastern to assume a more nearly horizontal posi- 

 tion. The foot-axis, viewed from one side, is now broken forward; 

 that is, the long pastern is less steep than the toe, and the heels 

 are either too long or the toe is too short. On the other hand, raising 

 the toe or lowering the heels of a foot with a straight foot-axis not 

 only tilts the coffinbone backward and renders the toe more nearly 

 horizontal, but tenses the perforans tendon, which then forces the fet- 

 lock joint forward, causing the long pastern to stand steeper. The 

 foot-axis, seen from one side, is now broken backward — an indication 

 that the toe is relatively too long or that the heels are relatively too 

 low. 



Lateral cartilages and plantar cushion.— The elastic tissues of the 

 foot are preeminently the lateral cartilages and the plantar cushion. 

 The lateral cartilages are two irregularly four-sided plates of gristle, 

 one on either side of the foot, extending from the wings of the 

 coffinbone backward to the heels and upward to a distance of an inch 

 or more above the edge of the hair, where the}' may be felt by the 

 lingers. When sound, these plates are elastic and yield readily to 

 moderate finger pressure, but from various causes may undergo ossi- 

 fication , in which condition they are hard and unyielding. The 

 plantar cushion is a wedge-shaped mass of tough, elastic, fibro-fatty 

 tissue filling all the space between the lateral cartilages, forming the 

 fleshy heels and the fleshy frog, and serving as a buffer to disperse 

 shock when the foot is set to the ground. It extends forward under- 



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