Hi Karen,
This is a good thread to start, I'm only seeing it now. Like you I too have been caught in the supermarket and I've had to grab a strangers trolley on many occasion to stop me just dropping to the floor with the spasm, the strangers trolley like that would see the tears in my eyes and I just hope that it eases for a minute and the stranger would help walk me to some chairs.
Thankfully my husband usually does the shopping and I tag along. I usually end up in bed for the rest of the day with some Diazapam and a book or TV and pray that it goes away by the next day.

Everyone hates the spasms and there's very little we can do about them but I've been on medication for them too and they've worked for me. I find one of those heat pillows on my back great.

That's my story I hope it helps.

All the best

Sinéad xxx