From the part of the rider it needs "much practice in collecting and balancing the horse and in using the aids correctly.
"[2] As in all dressage, the horse should remain relaxed, engaged, and responsive, with the poll as the highest point.
Pivoting around one hindleg without lifting it is not considered a correct movement: "The inside hind foot is raised and put down almost in the same place".
[3] When performed at the canter, the gait actually is meant to remain a three-beat action with a moment of suspension.
However, the high level of collection, strength and discipline required means that it often degenerates into an incorrect four-beat motion.