Explain the rising trot and how to do it?

The rising trot — also called the posting trot — is the technique of rising out of the saddle and sitting back down in rhythm with the horse's trot, using the horse's own movement to assist the rise rather than pushing up independently on every stride. It is the most fundamental trot skill for developing riders and remains one of the most used gaits at every level of English riding, not because it is easier than sitting trot but because it allows the horse's back to swing freely, encourages forward movement, and is genuinely kinder to a young horse's developing back than sitting trot applied before the horse has the strength and suppleness to carry a sitting rider comfortably. The mechanics of the rising trot depend on understanding the trot's two-beat diagonal footfall. The trot moves in diagonal pairs — left front and right hind together, then right front and left hind together — and each pair's push off the ground produces an upward impulse that the rising trot rider uses to assist the rise. Rather than pushing herself up with her legs on every stride, the correctly posting rider allows the horse's movement to carry her upward on one diagonal and then softly sits as the other diagonal comes to the ground. The rise is with the horse rather than against him. The mechanics of the rise itself begin with the hips. The rising trot is not a standing up and sitting down movement — it is a forward and up movement of the hips that allows the seat to clear the saddle briefly before returning softly. Thinking of the hips moving forward and slightly upward rather than straight up keeps the upper body from tipping forward excessively and keeps the rider's weight over the correct balance point. The knees and the stirrups provide the pivot point for this hip movement — the knee stays in contact with the saddle throughout the rise and the foot stays weighted in the stirrup. The return to the saddle should be soft and controlled rather than a drop or a thud. The rider controls the return through the same leg muscles that assisted the rise, allowing herself to descend softly into the saddle rather than falling back into it. A rider who bangs back into the saddle on every sit phase produces a horse whose back tightens in response to the repeated impact, which defeats one of the primary purposes of the rising trot. Learning the correct diagonal is the technical skill that develops alongside the mechanical skill of posting. The conventional rule is to rise with the outside shoulder — rising as the outside front leg moves forward. The simplest way to check the diagonal is to glance down at the outside shoulder and confirm that it is moving forward as you rise. When it is moving back as you rise, you are on the incorrect diagonal and a single extra sit shifts you to the correct one.