I'm assuming you are talking about doing the small universe on some else, who is lying down.
You obviously can't move your hands about the person's whole body, unless the are on a table. Even in a chair Master Lin doesn't pass his hand under the person.
What I do on my children when they are sleeping is to either use not physical hand motions for doing the small universe and just use my conscious thought, or to use one hand (or more correctly I visualize and energetic extention of my hand) and move the energy around the small universe as I would swirl water about in a tub.
The energy goes where you mind and the universe direct it. Although the physical portion does naturally influence energy movement, it is not necessary to move energy. Balance and flow are what you are seeking to create. Use the methods that are most appropriate.
You are perfection.
Iam2 