I'm surprised no one mentioned this:
when I cracked some ribs during my karate days, the sensei (teacher) would take a piece of corrugated cardboard and some athletic tape, and literally tape the cardboard patch over the cracked rib area.
make sure the cardboard is big enough so you tape it to the good strong un-bashed ribs adjacent to the cracked/bruised one.
sounds like a joke but IT WORKED!,..almost no pain when you cough, or laugh (try that now!) the only thing was removing the tape before a shower was kinda a beach.
but for the pain relief it gave when it was on, it was worth it
check it out.