When people refer to “your seat” they’re talking about how your butt stays or doesn’t stay with the horse when the horse is moving. It’s all about rhythm and knowing what rhythm you’re trying to stay with. In anything you do on a horse, if you know where and how he’s going to get there, you’ll be able to stay with him. When you aren’t sure… that’s when you become unbalanced, start to bounce, slide off the side, and/or come off the horse.
The first thing you need to do is study your horse’s movement. Start with a walk. Walk a lot. Experiment with your body. Move with the horse, move against the horse. Lead the horse with your movements then follow the horse with your movements. Try everything you can to get accustomed to the way your horse moves.
When you’re perfectly in sync, it’s comfortable for both you and your horse. Strive to be right with the horse. Then try something different. You can use your seat to help the horse change tempo: push into the saddle prematurely to speed him up, or lag a bit to help him slow down. Horses will generally aim for the place with the least resistance. So if your horse feels you pushing into the saddle to either slow him down or speed him up, he’ll adjust his pace to seek out the rhythm that doesn’t have your pressure. Show him where you want him to be and he’ll get there.
As you move into other gaits, the premise is the same—it’s just the way the horse moves that’s different. Practice. Get to know the rhythms. One thing that may help is music. Find songs that help you move with the horse. The Ants Go Marching always plays in my head in a walk. In a slow trot I usually hear It Takes Time to Be a Man by The Rapture. A canter I always hear This is Your Life by The Killers. A gallop, just the wind in my ears.
A big THANK YOU to Erin Barker for riding like a champ and allowing me to take pictures of it. You are awesome.