Thanks for the advice Tim, but I'm pretty sure it's a recurrence of a torn muscle problem from when I was in my 20's. It feels exactly the same and it's all right side lower/middle back. I'm just taking co-codamol in the morning and early pm. Usually by the evening it's eased enough that I can sit up for the evening and get a reasonable nights sleep later.

This morning is a lot better than yesterday so I don't think it's a spinal problem. You know, with the number of dinghy people i know that have back problems, it'd be a really good topic for the general forum. What are the exercises that you do Phill?

Not only worth talking about how to ease problems but also how to avoid them for those who don't (yet) have back problems.....

I'm thinking about things like good trapeze/hiking technique, keeping your back straight when you sheet in etc. I'm sure that on this forum there must be the expertise to advise us all?