Re: BklynMagus
Actually, no. You actually start with the hand slightly cupped with the thumb tucked into the palm and the other four fingers bunched together (the Swan position).
If you tensed your hand and made it rigid, you would make your knuckles more prominent and that can cause problems.
You should also be aware that there are two sphincters to navigate and that it you actually do not make a fist until you have cleared them both.
Once safely inside, a loose fist is best, both to allow for maximum sensation as well as to maximize awareness of the internal response of the fistee. Just as a surgeon needs a soft, deft touch, so too does a handball top.
^^^^
CB: "Fist" is a bit of a misnomer , then ? Macho , maybe ( "Men, so rigid") Massaging sounds closer.
On the other "hand", would seem that the bones of the hand provide underlying rigidity, relatively. Something limp couldn't push in.
Of course, women's hands have bones too. :>)