I spent most of my teenage years in the 60s,learning the art of undoing bras and now all these years later I find myself helping my wife every day to put hers on!Life is a sod,isn't it?
I suffer with severe arthritis .I cannot put a bra on and reach to fasten it at the back. Simple solution,put it on back to front,so the cups are at the back fasten it, and pull it round,heave your bosoms into it and pull the straps up over your shoulders.
Front closing bras are more often than not non adjustable and women with odd bust sizes have difficulty getting a proper fit. .