The other day I decided to keep raising the jump higher and higher until my horse started knocking rails. Normally I don't jump courses higher than 3ft, but I ended up going up to a 4'3 oxer before Sheena started hitting rails. It got me thinking, how do you know when you shouldn't ask you're horse to go any higher? I don't normally jump that high, I just wanted to see how high I could go. My horse is a 12 year old 15.3 paint/qh cross that loves to jump. I don't want to ask her to do anything that isn't safe or anything that is above her ability. Any thoughts?