One side to side exersise that helps me is laying in bed ...put arms straight down /palms down ..pull bent knees up as far as you can toward face (feet are off the bed)...then roll from side to side over your arms. Use the balance of your arms against the bed and use your muscles to turn back the other way. It is not easy at first, but it will also train your body for turning over in bed and getting out of bed... which so many people find difficult later on. You have to create new muscle memory You Can Do IT. Someone can help you at first to push your knees over and help you come back to the other side until your body learns what muscles to build up and use to accomplish this. Just having someone turn you back and forth in this way will loosen stiffness the whole way along your back. I started doing this exersise years ago in Florida when trying to strengthen my core to try to learn to flip a kayak. *Never got the kayak flipped over and back up, but I didn't have one that fit me snug so we could move as one...think I would have made it if fitted properly.