Because it is so mountainous where we train, all the horses wear breast plates. Most riders use the Zilco or biothane ones. They interfere with the horse a lot less than a slipping saddle.
Some also use a crupper, and I should be one of those. Even though Hunter has nice defined withers, his saddle will still slip forward on a steep descent. . I'm too old for the rodeo that might result from a crupper on this little guy. I have used a crupper on Twist, but he is also a driving horse and quite used to a crupper. Nancy