The gait I am talking about is not a rack. It's still a trot, but there is
slight positive dissociation, where, an instant before foreleg impact, there
is hindleg impact. Seldom will any horse have simultaneous impact when viewed
in slow motion. Some have negative dissociation, which, if maintained later
in life, makes for a very poor athlete.
There was one French trotter, Ideal Du Gazeau, which was complained about as
not trotting during the acceleration phases of his races. He'd reach up and
under so far that occasionally a forefoot would cycle through without
touching the ground.
ti