One word Goose - Stretching
You have been away from the back breaking work and your muscles get out of tone, the back brace may help to remind yourself to tighten up your stomach muscles when you go to lift something heavy, but you are getting to the age where you have to be very careful of your back. Don't overdo it. Stretching and staying limber can prevent injury. Sounds like you need to strengthen the lower back muscles back up again.
Maybe do some research and not ask a bunch of obsessed fishermen
