Roached back while jumping?

Take a riding crop and thread it through your arms.You are sitting normally on the horse, holding the reins. It rests on the inside of your elbows but goes behind your back. This forces you to be in the correct position and will not allow your shoulders to roach. FYI: This is uncomfortable! Definitely start this on the flat so you can get used to it and make sure you have your balance. You have probably already been doing this, but ride around on the flat in your jumping position and make sure your back isn't roached. Even over arch it. Hopefully this will make the muscle memory kick in and it will be natural over jumps. Another possibility is that you don't have a lot of core and shoulder muscle. Do shoulder and core strength exercises and see if that doesn't help.

Good luck and don't give up!

When your going over a jump, imagine somebody pressing a plank down on your back that touches from your butt to your shoulders. This should help. Also try reaching your hands out further down the neck and stretching your back out. Don't go too far, though.

Don't give up, though. Riding is just too fun to quit on! Keep at it. Personally, I've been stuck doing three-jump cross-rail courses for the past year or so and that was pretty boring. But during the summer, I got to finally start doing much longer courses with verticals and if felt so great to finally be moving forward again. Just keep thinking about how good you'll feel when you finally succeed and keep trying.

I used to do that... i focused on arching my back as much as possible then my back became straight when I went over the jumps. Another thing that I did was think of shoving my shoulders back when I was sitting down in class or just anytime because then my posture would be better when I was riding which ended up effecting my jumping position (in a good way). My jumping position still isn't perfect but its A LOT better than what it was before. I would try that. It worked for me in a big way.

My best riding class was when my instructor had us put on a blindfold and put our horses over a cross-pole jump. There must have been 5 teenagers and one 30-year old. Me. I was shamed into doing it. Closing your eyes does not work. Just put the blindfold over your eyes and trust your horse. Doing this will help you "feel" the moment you need to rise into a two-point.

You must use an indoor arena, all doors closed, other horses with yours so she feels safe, and your riding instructor moving your horse. No reins, use a halter so you don't grab and hurt her mouth.

Also you might have someone lunge your horse while you are seated, no stirrups, to gain your balance. No more than 15 minutes each way or else you could hurt your horse's shoulders.

You should take pics or videos and look at what your doing and compare to more experienced riders with nice positions. I had no idea what I looked like until I took pictures.