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The horse's submission
When the sacral joint closes the horse is empowered. When it opens the horse deactivates. The rider - while doing work in hand - softly touches the horse with a dressage whip and asks it to step with its hindlegs sideways. This movement stretches the haunches laterally. As a result the horse strikes off in an elevated trot and remains its cheerful self. Pizazz and the urge to perform are unchanged.
Or, the rider in hand asks the horse to yield its hindquarters. He does so by fixing his eyes on that triangle in the area of the widest lateral extension of the pelvis where in the equine hindquarters major postural and locomotive muscles meet. The horse yields and respectfully opens the sacral joint. It subsequently does not strike off big but drops the neck and picks up a small trot.
Psychologically there is a big difference in what appears to be the same side stepping motion. In the first case the sacral joint activates. The horse is the master, the rider its well-meaning partner. In the second case it deactivates. The rider is the master, the horse his willing servant.
From the sacral joint at the rear end of the cantilevered back bone the horse manages forward locomotion. From the front end of the cantilevered back bone it controls speed and direction. The rider in hand asks the horse to shoulder-yield. Touching the neck with the lead rope, lunge or rein and with his hand covering the horse's eye he drives its head and neck away. It turns around the haunches. The neck leans into the direction of movement. The shoulders are stretched.
If the rider combines this lesson with hindquarter yielding and distinct lateral neck bending, the horse in an instant apprehends and consciously activates the control function in the forehand's center. It thereafter strikes off in a small well-balanced trot. At the rider's command it tunes down to the walk or halt. It tunes up to a canter or big trot.
Without further comment, an approach which in one calls on the horse's submission while fostering self-control is preferable to the mere development of equine gaits. After all, to achieve maximum performance, the jockey for instance must yield ninety-nine percent of the control. A question remains. Will the horse after complete surrender ever again raise neck and withers, change to performance position and work in second gear? Will it remember the mood that produces elevation and sublime lightness?