The full nelson is executed by the person penetrating a person to be behind a person and hooking their arms from outside inwards behind the legs and placing their hands behind the recipients head. This folds the receiving person by the hips and opens up their legs wide and open, their knees being close besides either side of their head.
The position can be done when standing up, but also when having the recipient lay on top of you. From behind penetration can than happen.
