i have a exercise that was given to me by a posture doctor:
1.lie on your back in a sit up position
2.breath deeply in to your lungs
3. hold for 2-3 seconds
4. exhale and push down the ribs
!!!important tips!!!:
DO not work your abdominal s or obliques
pretty much don't work your any ab because that will put unnecessary pressure one your sternum and will make it even worse.
do 10-15 times, 2-3 reps
please tell me what you think and if it helps.
to me it is the best exercise because after i do it you almost cant see the rib flare.
(another exercise(that i think is in bjorn blog but i didn't have time to check
inhale as much as you can to your lungs
hold for 10-15 seconds
exhale easily
is you fill dizzy you should hold for less seconds, this will also improve your posture.