How do you develop rhythm and relaxation as the foundation of correct movement?

Rhythm and relaxation are the two most fundamental qualities of correct movement in a horse under saddle, and they must be established before any collection, lateral work, or more demanding training can be correctly developed. Rhythm refers to the regularity and consistency of the footfall pattern at each gait — the clear four-beat walk, two-beat trot, and three-beat canter — and relaxation refers to the horse's physical and mental state of ease that allows it to move freely through its back and topline without tension or resistance. These two qualities are interdependent. A tense horse will always have some disruption in its rhythm because tension causes the back to tighten and the stride to shorten or become uneven. A horse that is rhythmically irregular is almost always tense somewhere in its body, and that tension must be addressed before the rhythm can become consistent. Developing rhythm and relaxation requires long, patient warm-up periods at a forward, active pace before any collection or demanding work is asked for. Allowing the horse to stretch forward and downward at the trot and canter — reaching its nose toward the ground and swinging freely through its back — develops the topline suppleness and relaxation that rhythm is built upon. Transitions between gaits, performed frequently and from light aids, develop both rhythm and the horse's ability to maintain relaxation through changes of pace. A horse that moves with a clear, consistent rhythm and a genuinely relaxed, swinging back is pleasant to ride, develops correct musculature, and has the physical foundation for all more advanced training.