When doing a rear delt fly or bent over lateral(these are the same yes?) what is the difference in recruitment with the grip pronated or the grip in neutral(where there is more external rotation)?
I've seen videos of both.
I'll give my thoughts although there are certainly more qualified people on the forum to answer this question.
When I do the rear delt fly I feel it more in my back.
Bent over lateral raise is more of a shoulder exercise to me. I only bend over about 30 degrees.
Can't help you w/ the grip question.. Sorry