96 LIVE-STOCK JUDGING 



the hind legs serving as propellers. The articulation of 

 the thigh directly with the pelvis conveys the propulsive 

 effort throughout the entire length of the spinal column. 

 The supportive action of the forelegs meets the propul- 

 sive action of the hind legs in such a way as to restore the 

 equilibrium of the body. 



The joints of the leg are hinge joints, capable of motion 

 in two directions only, flexion and extension, while the 

 joints of the hip and shoulder, points at which the legs 

 articulate with the body, are ball and socket joints, which 

 permit of a rotary motion. The legs, generally speaking, 

 are therefore capable of alternate flexion and extension, 

 which take place in the order named, although the flexion 

 of the leg as a whole may involve the extension of some 

 one joint, as in the case of the shoulder at the commence- 

 ment of flexion of the leg. 



89. The stride. Flexion of the leg, which raises the 

 foot from the ground, plus extension of the leg, which carries 

 the foot forward until it comes in contact with the ground, 

 again constitute a "stride, and by the simultaneous or suc- 

 cessive strides of the four legs, regularly repeated, the body 

 is advanced. Each leg may engage in a stride inde- 

 pendently, as in the case of the walk and the rack or single 

 foot, in which the cadence is distinctly marked by four 

 beats; one fore and the opposite hind leg may operate 

 separately, while the other two act as one, as is done 

 in the gallop, there being three distinct beats but of 

 irregular cadence; a fore and a hind leg may move in 

 unison and mark but two beats, as in the trot, when a 

 diagonal pair are concerned, as the near fore and the 

 off hind, or in the pace, when a lateral pair, as the near 

 fore and the near hind, cooperate. 



90. Deviations in the stride. There is an active and 



