My boyfriend gave me the back knobber to use one day when he was too lazy to give me a massage (feel free to roll eyes here!). But honestly, it was fantastic. The knobber reached the parts of my lower back and shoulder that are always aching and in need of some hard core kneeding. It's curved shape made it easy to use and easy to reach my middle and lower back. I promise you, after this your knots will be gone (at least for a day).
Two warnings though. one) It looks like a kinky sex toy so do not leave it lying around when you have guests coming over. two) It is ONLY for those who like deep tissue massage. Otherwise, you will hurt yourself.
My only complaint is that my kneck often hurts a lot too. But this contraption won't work on the neck.