If you find that you need to massage your back and do not have anyone to help you, try the following:
You will need a pillowcase, a tennis ball or two.
1) Place tennis balls in the pillowcase, 2) Hold the end of the pillowcase over your shoulder and stand against a clear wall, 3) Move the pillowcase accordingly to be placed where your back aches, 4) Move yourself against the wall and you will feel the tennis balls working on your back.
Neat trick. It helps when there isn't anyone available to help you. I hope this helped you.