REARING. 



91 



{see p. 119, et seq.). By doing this, we "lighten" the hind 

 quarters and accustom him to hft them and move them freely. 

 In the rear, the horse usually keeps one hind foot advanced 

 more than the other, and his hind feet more or less apart, 

 so as to widen the base of support. 



The rear is a particularly insecure and fatiguing attitude 

 for the horse to maintain ; as the column of bones formed by 

 the body and the hind legs has to be kept in position, 

 at its joints (or angles), by the exercise of muscular force. 

 In a biped, like man, this column of bones can be brought 

 into a nearly vertical position, so that its component parts 

 can rest on each other, with but little muscular exertion 

 to maintain them in that position. Owing to the large 

 amount and continued nature of this muscular effort, there 

 will be a very appreciable backward and forward sway 

 (caused by the alternate contraction and relaxation of the 

 opposing muscles) at the various joints. This, added to 

 the narrowness of the base of support (formed by the hind 

 feet and the respective lines which join their toes and 

 heels), will render the rearing position so insecure that, to 

 support it, the horse will have to keep frequently changing 

 it. The danger of falling backwards which the animal incurs, 

 if he gets too erect, will naturally help to deter him from trying 

 to assume a comparatively vertical position. Hence, he will 

 have to keep the joints of his hind limbs more bent than 

 if he was not exposed to this risk of falling backwards. 



The hocks are particularly liable to injury from rearing, 

 owing to the great strain thrown on them when the animal 

 assumes an upright position. " Curbs " and other enlarge- 

 ments are of frequent occurrence among circus horses which 

 are trained to walk on their hind legs. 



