I use one of these when I'm having issues (Elctrician with heavy hands on work). It's my second one in 8+ years. It allows my back muscles to recover whilst being able to carry on with lighter duties. Personally, For the money I think they're fantastic. Just recommended this to a friend. He said the same.
If you think it's spinal, See the Doctor. If you think it's a pulled or tired muscle, This might work for you. If you're in doubt, seek medical advice.
Amazon.co.uk User Recommendation