not to cause further controversy, however, i was once an avid trainer many years ago, now i'm back in the gym at 33, and haven't trained seriously in about 5 years, i started last november, i was getting CHEST size back from pressing but was lacking the middle. I started doing moderate weight cables, not crossing the hands, just letting them meet, at full contraction i was twisting my wrists in, making my palms face up. i would alter my arms from workout to workout, sometimes completing the squeeze in front of my face other times down by my abs and sometimes in between, within a month, the line came out.
case in point, regardless of what movement you do, IMO it's all about the SQUEEZE...