Thank you, ***** *****
This Lady showed me the Rib in question two evenings ago ..
It is a Front Rib, and, seemingly, the uppermost one,on her right hand side.
She offered to pop it out herself as a demonstration, but I declined this offer!
I can't specify any particular situations / actions which might trigger the problem, but this Lady works under a lot of stress ..
One occasion was at a recent Family Christening ..
She is currently undergoing a bad patch with her partner (my son) ..
So I wonder whether stress might be to blame for an inherent weakness surfacing?
I don't know whether this Lady is 'double-jointed' ..
I hope that the information I have given you is sufficient for you to advise regarding the situation which is, quite naturally, making her feel vulnerable, and less able to conduct her job, within which she is a Manager ..
I look forward to your reply ..