Hi, after suffering bouts of both back pain and RLS I invested in a Power Plate [looks like a treadmill] second hand off ebay and it was the best £25 I have ever spent in my life. Brand new they are self-assembly and cost about £200 for the full version but smaller units can also be bought, although I have not tried one of these.
I use it for 10 minutes most days and my back is measurably better and stronger. My only bout of restless legs since using it was stopped in its tracks by standing on the machine with my knees bent. By setting the vibrations to a high frequency the machine literally shakes the restlessness out of my limbs.
Many gyms have these machines so anyone could go for a try to see whether or not one of these could help, before actually buying one.
They are also useful for weight control & circulatory problems.
My house is only quite small and the machine does take up a bit of room but its benefits far outweigh this disadvantage.
Well and truly recommended!!