Background
I've been fooling around with some variation in grip width on the bench press lately.
I've had a trainer help me find my "ideal" width, which I use most of the time. I.e. the width where my forearm stays as perpendicular as possible to the floor for most of the lift, while neither flaring nor tucking the elbows.
In these cases, my form looks like this. (Not me depicted, just an example.)
But I some times like to use a slighly more narrow grip - about a palm-width in on each hand. Just outside the shoulders. It looks something like this:
Question
What are the implications as far as muscle group intensities? Does it fill the role of if your muscle X is weak, do more of this for any particular muscle group?
This question is similar to, but not a duplicate of, Bench press grip width?, as I am not looking to discover the optimal width, but simply clarify benefits/drawbacks of a slightly narrower-than-normal width.