Actually my main problem is that I have the tendency to want to lean back "in the saddle" like a rodeo cowboy which has caused my H to have to bounce me off with an "ouch-yowee" on a couple occasions. So I have to think too much about not doing that and it distracts me. I'm surprised he still is into it .
I can understand this, i have the same problem...when i'm on my back, 90 degrees straight up is about as far as i bend before it starts to hurt. This also makes WOT facing feet a position that i can't do which is so unfortunate because i so love that viewpoint