In saddle seat equitation the rider makes every effort to show the high leg action of his/her mount--one of the gaited breeds such as the American Saddlebred.
Saddle seat riding developed in the United States, and is also practiced in Canada and South Africa--and to a lesser extent in Australia and Europe. In equitation classes, the rider is judged on how well he/she displays the talents of his/her mount.
Gaited horses have exaggerated movements, especially at the trot. They are ridden and shown only on the flat (no jumping).
The saddle seat rider's position, attire and tack differs greatly from two other English disciplines, hunt seat and dressage. Riders sit farther back in the saddle (which has wider skirts), with hands held much higher. In fact, equitation riders are penalized for leaning forward or dropping their hands.
There's a reason for this position--the rider sits behind the horse's center of balance, freeing the front legs and encouraging the high action. The gaited breed you'll see most often in saddle seat equitation classes is the American Saddlebred. But you may also see Arabians, National Show Horses, Tennessee Walking Horses, Racking Horses, Spotted Saddle Horses, Morgans, Friesians, Andalusians, Hackneys, Paso Finos, Missouri Foxtrotters, and Rocky Mountain Horses