The rider can't help but impact the horse with his seat. He uses his hands to communicate and facilitates his feet to propel it on. Legs, pelvis, vertebra, ribs, shoulders and arms, in short the whole of the body, plays a role. The rider may use the distribution of his weight to balance the horse and from his core release its energy.
The rider's seat
The rider sits still on his place in the horse's back. His pelvis is level, the sacral joint at center, the sacro-illiac joint released. The latter permits a degree of elasticity in the pelvis. It activates human core energy. Two concurring provisions, a place for the rider in the horse's back and the release of the human sacro-illiac joint, permit the rider to sit movements in the horse's back. By the same token his energy directs the horse's energy. Spoken of is the seat, which exclusively and from earliest times riders used to ride the horse; up until the late 1700s and the beginning of modern times.
Today we ride a different horse. Modern equitation depends on the rider's success in making himself welcome. Horses who do not want the rider to sit bounce him. If this is the case it is of advantage to post, float or, better yet, to remain in the walk until the horse consolidates, settles in the haunches and raises in the withers. It will then, from the very first strike-off, offer the rider a comfortable seat. The fully mobilized horse permits the fully seated rider to lean slightly in the lumbar vertebrae and transfer the focus of energy from the sacrum to mid-back. Horses with a good back and strong supple haunches love it.
In modern equitation the rider facilitates his body's structural and energetic faculties to tune into the horse's needs. There are two additional seat options, which directly speak to the horse. In the forward seat the rider slightly hollows the lumbar vertebrae and, seat raised, thus addresses simultaneously the horse's energy level and its haunches. This seat demands a change of position in the rider's sacral joint. It closes, a bit like in walking uphill or framing up for an action that requires energy. As a result the pelvis tips to the front. The complimentary effect evolves in the cowboy's sliding stop. Here the rider's pelvis tips back. The sacral joint closes and the flow of energy is cut; a bit like resting in a lounge chair.
It follows that teaching the seat in a new modern equitation is more than learning the traditional upright seat and any of the floating or forward seats, which are practiced today. It calls for a schooling that one, informs the rider of his/her options, two prepares ways to facilitate them, three according to the horse's needs and the task at hand.
