Protraction and retraction limbs angle measurements in a sample of the Colombian paso horse. P1: Coronary band front; P6: Scapula (top of the withers), P7: Coronary band hind, P12: Sacro-iliac joint (Tuber coxae). The dashed points show the angles measured when the horses were trotting without a rider. Protraction was the maximum angle between P1-P6 and the vertical plane when the forelimb was extended forward. Retraction was the maximum angle between P7-P12 and the vertical plane when the hind limb was extended backwards. | Image: 2018 Novoa-Bravo et al., Selection on the Colombian paso horse's gaits has produced kinematic differences partly explained by the DMRT3 gene/Creative Commons

However, a new study suggests the trocha isn’t all that genetically similar to lateral gaits in other ambling breeds like Icelandics, Tennessee Walking Horses, and pacers. While the gaitkeeper gene (DMRT3) appears to have some influence, the trocha appears to be coded by additional genes as well, said Miguel Novoa-Bravo, PhD of the National University of Colombia Department of Biology, in Bogotá.

In fact, he and colleagues from the Swedish University of Agricultural Sciences, in Uppsala, found the trocha actually has a diagonal component in it in addition to the lateral one, which might explain why the gaitkeeper gene only has a partial influence.

“The trocha is a lateral sequence four-beat gait, but it’s actually diagonally coupled,” Novoa-Bravo said, adding that the Missouri Foxtrotter’s foxtrot is similar to the trocha. “That means the forelimb hits the ground before the contralateral hind limb. So it has to be considered a diagonal gait, mainly because the time it takes to perform the diagonal movement (opposite fore-hind limb sequence) is shorter than the time it takes to perform the lateral movement (hind-fore limb of the same side)