Thanks to Random Guy and Phil once more.
It would seem that habits are learnt and can become subconscious.They may be learnt accidentally rather than deliberately, but once established they are there for good.( or nearly?) I have been lead to believe that once learnt, that's it. Unlearning is all but impossible. Better to learn something better and establish that than try to stop doing whatever it was, does that sound about right?
The forward loose has always seemed to me to be a flaw in so many archers' technique. Perhaps I mix with the wrong people!
I believe, as you do that it is poor back muscle control. I would go further and add that I feel it slowly becomes part of the technique when there is no one around to help correct it. It then becomes something they DO without realising.This can so often lead to looking in the wrong place for a solution.
What started this all off was something that I do as a coach. I tend to use the example of tying shoelaces, and how we get to be able to do it without looking, to help explain how some bad habits get into our shooting. That seems to take the guilt out of the archer.( they often seem to want to justify why they make mistakes as if they are at school and about to be punished)
I have been a bit concerned recently that I was using the wrong words to describe what is going on. Using "subconscious" etc when perhaps that's the wrong word. If I am wrong then I need to know what is right. If I sound a bit nit picky, then it's only because I want to know for sure, rather than hope I'm right.
Thanks for your inputs, I feel better already.