When a horse “dwells,” it doesn’t keep its impulsion through the air, but slows down slightly at the peak of the arc, so that it appears to be suspended in the air for a moment. As a result of the loss of momentum, the horse’s landing spot will often be closer to the center of the fence than the take-off spot, instead of being correctly the same distance from the fence.
To correct the problem, the rider must push the horse through the air with his legs, and, if this is not enough impetus, must use his stick on the barrel of the horse to reinforce his leg aid. The goal is to create one continuous flow of energy through the air, so that the jumping effort will be more athletic and, thus, safer.