I am backing a horse for a couple and I am doing it on their property. She is officially 'green broke'... mostly trustworthy (no offers to buck or rear) under saddle, but doesn't know it all yet. I went out there today and they'd had her saddled up with a breastcollar and a back cinch. I never used either of those things on her because, in my opinion, they can be irritating on a green horse. Not so much the breast collar, but couldn't the back cinch make them kick out if it tickles their belly? I don't want to add any unnecessary tack at this point, especially since she's green. Maybe later on when she's been exposed to more things.