Probably differs for every species, right? Birds have lighter bones and all. Actually, we'd probably need to know where everyone's heart is...there might be medical records about that?

[ Not his department. But worth asking. ]

Don't worry too much. Cracked ribs can be fixed. Easier than death. I mean...well, we kinda revive here, but I don't think people want to die too much and test the tether.