Physio said - EXERCISES! - and gave me eight to do three times a day - also STAND every 20 minutes.
Well if it will improve my back and posture I'll give it a go.
I'm putting a self reminder pic down the side here and I'll have to set a timer every 20 minutes to remind me to 'jump up' as I'm sitting for hours here or stitching.
Maybe I should have chosen more energetic hobbies in the first place!