Holding all other factors constant, does direct bicep work have an affect on deltoid definition, mainly the definition along the transition of biceps and anterior and lateral deltoid heads?
Yes. Unless you’re fat
Definition is usually tied to leanness, but in terms of developing the area you’re talking about, it can, and how much it does depends on how much the particular variation of curl you’re doing stresses that area. For example, incline curls (curls while lying back on an incline Bench and letting your arms hang down) will stress and stretch that area far more than any curl variation that has your elbows at shoulder level.
For that particular area you’re discussing though- and I think @The_Mighty_Stu has discussed these recently - reverse grip shoulder presses would do a much better job of hitting that, IMO.
If anyone has never tried reverse grip Military presses, I recommend taking them for a test drive. You’ll understand things in a way you hadn’t before.
No it does not, unless you are doing a dynamic movement that trains both. And honestly, there are no established movements that simultaneously train biceps heavily and delts heavily except for barbell cheat curls. And why would you wanna do barbell cheat curls?
You and @flappinit piqued my curiosity.
Who came up with it anyway? I’ll go look it up.
I will definitely try these next shoulder day. Right now I’ve made shoulders a priority over chest on my chest/shoulder day. Been doing dumbbell OHP’s for my main movement. I’ll definitely give these a whirl and I’d try anything to make dem dare bowlin ball shoulders