hurting my side on legs hangs, jade, and allegra

Hi folks, My question is...Will I get over hurting my back and sides from legs hangs, jade, and allegra. Especially the allegra. It's slowing down progress a lot since I have to take to much time off to recover from it. How many inverts in a session are too many. It is really not the skin either, it's the muscles underneath. I have a really short waste, and the pole ends up hitting my back ribs a lot. It is just a newbie thing or is their a technique I'm missing..?