Hmmm, Why did i assume you were from Sydney???

Anyway, You can still ring Barb's place and ask who in Melbourne / Vic does this stuff. It is not a common treatment technique.

I have lots of questions for you!

Is there anything that you can do to help the pain - e.g. when you open the door (heavy) can you push into the rib to see if it stabilises?

Have you tried to self manip your T/S. I know that sounds wild but a lot of people do it just by extending their T/S with their hand behind the back. I am NOT telling you to manip your spine just to see - just asking if you have already tried it or it has happened accidently. Don't do it if you haven't.

Have you had a cold lately? Coughing or sneezing can do it.

have you changed bra types lately? A bra too tight, esp with underwire can cause altered rib function

You mention T4 being tender. Also, 4th rib is tender. Have you recently started any exercise that you are unaccustomed to? Often external obliques being overactive can cause splinting of the T/S up to and including T 5 via the 5th ribs. This can then cause T4 to move excessively over T5 causing your rib dysfunction +/- T4 problems. A common giveaway is that you will have a crease above the umbilicus.

You mention radiating pain down the left arm. Exactly where is it and where does it go?

Seated arm lift...Sit and FF one arm to about 90deg. Does it require more effort compared to the other side? Does "core" activation help - i suggest a gentle anterior pelvic floor contraction?

Please answer the above - i am more than happy to help!