FORM AND ACTION OF THE FOOT. 25 



The Foot as a Whole. 



The details I liave given of the structure and uses of 

 each separate part of the foot will, I hope, be sufficient 

 to enable us to understand the form and action of the 

 organ as a whole. 



No one part of the foot is of greater importance than 

 -another; each is dependent for its highest development 

 and soundest condition upon the integrity of neigh- 

 boring parts. 



A weak wall allows of the flattening and spreading of 

 the sole, whilst a weak sole permits contraction of the 

 wall. Overgrown heels cause wasting of the frog, but 

 low, weak heels are usually accompanied by excessive 

 •development of frog. 



The special function of the foot is to sustain the 

 weight of the animal whilst standing or moving. The 

 horse standing squarely on all four feet rests his weight 

 chiefly on the lower circumference of the wall. On level 

 ground, the sole, on account of its arched form, takes no 

 direct bearing, but if sole and wall be sound, a propor- 

 tion of all pressure applied to the wall is transmitted to 

 the sole. So, also, must all weight imposed on the arch 

 of the sole be transmitted, through its abutments or 

 union vdth the wall, to the wall. If the sole be so thin 

 that it yields to pressure, then its proper action is des- 

 troyed, and instead of acting like an arch and supporting 

 weight imposed on it, it yields, and injury results. The 

 arched form of the sole indicates that it was not intended 

 to take a direct bearing on hard ground. On a soft sur- 

 face, the edge of the wall sinks and the whole under 

 surface of the foot takes a direct bearing. Pressure of 

 the sole on the soft surface does no harm, because it is 

 diffused evenly over the whole of the sole. We take 

 advantage of this when the wall is diseased or injured, 

 and we desire to throw on the sole a larger share of 

 weight. We turn such animals out into a soft field or 

 stable them on sand or saw-dust. Any system of shoeing^ 

 founded upon the true form and action of the foot must 

 recognize the arch, and not endeavor to force the sole 





