seated Preacher curls with a Barbell...ez bar don´t work for me.
Scott wrote several articles years ago in which he described doing supinated preacher curls using a curl bar, but gripped so that the little finger side of the hand was higher than the thumb side; basically, the opposite of how you would normally grip that bar.
The idea is that, angled the traditional way, the move is easier - thus, less effective.
A straight bar is more effective.
Larry's grip was supposedly even more effective because it is harder and, in turn, stresses the biceps more.
(He often employed this hand position when doing db preachers.)It should be noted that the bar he used in the illustrations was not the typical EZ bar, but the kind that is significantly
less angled.
I don't know for sure, but this may be a Gironda idea, as he was keen on making those kinds of minor adjustments to conventional exercises.