National Geographic : 1923 Nov
Sketch byEdward Herbert Miner THE TROTTER, THE PACER, AND THE RUNNER IN ACTION This sketch shows the three gaits which horses assume when traveling at speed, in the relative positionswhich thespeed ofthedifferent gaits would place them. The trotter (left) strikes, at the completion of each stride, on the forefoot of one side and the hind foot oftheopposite side; thus always the legs of the same side move in opposite directions, the forefoot being raised before the hind foot of the same side passes over toitslanding position. The pacer (center) moves the two legs of the same side together in perfect rhythm, both when leavingthe ground and when landing; this gait is clearer from interference than the trot and is a little faster. The runner (right) differs entirely from theother two, inthat attheend ofeach stride he lands on one hind foot. After the impetus of the next stride has been given by the hind quarters, theweight isplaced entirely upon one foreleg before the animal leaves the ground. It is this peculiarity of stride of the runner that places so much more strain upon theThoroughbred race horse than is borne either by the trotter or the pacer. Both the latter, with only a light harness upon them, bringtheir weight down upon two feet, whereas the weight of the runner and of its mount is thrown entirely upon one.