phil heath's back is just like phil heath's chest.
it cannot get WIDER.
It will get bigger, thicker, and more bunched up.
But wideness is a genetic thing.
If you can find a pic of Phil heath and Vic martinez standing right next to one another, you'll understand immediately. Vic is 6 or 8 inches WIDER. So his chest and back will always be wider.
Phil has amazing arms, but back/chest are near max. All they do now is getbunched up and ruin his symmetry.