Where would you advice me STRAP MY BABY, BACK OR CHEST?

From a young woman:
I don’t really like the idea of strapping my baby on my back but my mother never stops complaining about the chest idea either; she says it’s safer on the back. So I seek your opinion here with convincing reasons. “Where would you advice me strap my baby, back or chest? Which is safer?”
What’s your take on this, comrades? “… with convincing reasons”; in addition, perhaps with relevant instances. Thanks.