Yeah, I remember that from my readings a long time ago. Don’t pull from the head! Apparently there are a bunch of important nerves on the top of the penis, just below the head. For this reason, I have also seen it recommended that when you jelq underhand (thumb on top) to stop an inch or so short of the head.
I have seen videos of people stretching and jelqing with no heed to the warnings others have posted, but I choose to heed them.
When I stretch, since I am targetting the ligs, I grab the base of my penis, and put as little force as possible near the head.
My $.02,
Cdr.Blop