Once the round pen basics have been laid, the colts foundation progresses with groundwork. The essence of these exercises is to get the horse's body and mind engaged. The colt learns to give to pressure, to soften his head and to disengage the hind quarters.
Softness in the face is what keeps the riding horse from pulling on the bit and is part of the foundation required for collection. Disengaging the hind end is the safety brake on your horse. In any problem situation, pick up on one rein and ask the horse to disengage the hind quarters. To do this the horse must step over on the hind end with the inside leg crossing in front of the outside hind leg. This takes all the drive away from the horse and brings him back to an exercise he knows and trusts.
The small circles and constant changes of direction encourage the colt to sharpen his mind and adapt his thought process quickly to changing commands. At this time the horse can be taught to turn on his back end and sets the foundation for roll backs.