Center a heavy dog on his bed
If your dog has a mobility problem or is paralyzed, sometimes he will land on his bed crooked or too close to the edge or backward. This article explains how to center a heavy dog on his bed using a garbage bag.
Take a heavy duty tear-resistant garbage bag (eg. Hefty) and put your hands and arms inside it. Then slip your bag-covered hands under your dog palms down and push your hands until they are all the way under him. This is surprisingly easy to do, because the garbage bag reduces friction.
Once your hands and arms are under the dog, you can move him around on his bed, keeping your palms flat on the mattress. There is no lifting involved, you are merely pushing forward. Lifting in this position may hurt your back. Just push your hands under and then "float" the dog to the correct position. His body will be lying on the backs of your hands.
When you have your dog where you want him, pull your arms out of the bag and pull the bag out from under him.
This trick is better for your back than bending over the dog and trying to pull him to the center of the bed. It is also better for your dog because you reduce the friction of his skin dragging across the bedding, which should help prevent bedsores.
It works well on an orthopedic mattress. I have not tried it on a fiberfill dog bed.
This idea is adapted from a caregiver tip for humans found in the article, "Moving a patient in bed when you don't have a draw sheet".