Or balancing of the horse is used to
1 Prepare for transitions, up or down.
2 Create or maintain the horse’s shape.
3 To rebalance if he speeds up.
4 To set your horse up for a new movement.
The rider has to stay sitting steady on both seat bones with good posture. The rider’s legs demanding quietly for energy that will bring the horse’s hind legs more under his hips and close the baseline.
The hand regulates the impulsion and every time the horse “gathers himself”, the rider’s hand should yield slightly, keeping the contact but not acting backwards. In the yielding, you should feel the horse is light on the forehand and balancing without the rider holding other than a springy soft contact.