LAMENESS: ITS CAUSES AND TREATMENT, 305 
Our first consideration should be the physiology of normal or 
healthy locomotion, that thence we may the more easily reach our 
conclusions touching lameness, or that which is abnormal, and by 
this process we ought to succeed in obtaining a clew to the solution 
of the first problem, to wit, in which leg is the seat of the lameness? 
A word of definition is here necessary, in order to render that 
which follows more easily intelligible. In veterinary nomenclature 
each two of the legs, as referred to in pairs, is denominated a biped. 
Of the four points occupied by the feet of the animal while standing 
at rest, forming a square, the two fore legs are known as the anterior 
biped; the two hinder, the posterior; the two on one side, the lateral ; 
and one of ‘either the front or hind biped with the opposite leg of 
the hind or front biped will form the diagonal biped. 
Considering, as it is proper to do, that in a condition of health 
each separate biped and each individual leg is required to perform 
an equal and uniform function and to carry an even or equal por- 
tion of the weight of the body, it will be readily appreciated that 
the result of this distribution will be a regular, evenly balanced, 
and smooth displacement of the body thus supported by the fon 
legs, and that therefore, according to the rapidity of the motion in 
different gaits, each single leg will be required at certain succes- 
sive moments to bear the weight which had rested upon its congener 
while it was itself in the air, in the act of moving; or, again, two 
different legs of a biped may be called upon to bear the weight of 
the two legs of the opposite biped while also in the air in the act 
of moving. 
To simplify the matter by an illustration, the weight of an animal 
may be placed at 1,000 pounds, of which each leg, in a normal and 
healthy condition, supports while at rest 250 pounds. When one of 
the fore legs is in action, or in the air, and carrying no weight, its 
250 pounds share of the weight will be thrown upon its congener, or 
partner, to sustain. If the two legs of a biped are both in action and 
raised from the ground, their congeners, still resting in inaction, will 
carry. the total weight of the other two, or 500 pounds. And as the 
succession of movements continues, and the change from one leg to 
another or from one biped to another, as may be required by the 
gait, proceeds, there will result a smooth, even, and equal balancing 
of active movements, shifting the weight from one leg or one biped 
to another, with symmetrical precision, and we shall be presented 
with an interesting example of the play of vital machanics in a 
healthy organization. 
Much may be learned from the accurate study of the action of a 
single leg. Normally, its movements will be without variation or 
failure. When at rest it will easily sustain the weight assigned to it 
36444°—16——20 
