From the Brotherhood of the Phoenix email list:
"I am a Disabled gay male witch and I need information on casting a circle from a wheelchair can anyone tell me any information on alternatives for casting a circle for paraplegics."
If you're feeling unsure about what you're doing, you may want to contact an experienced Witch in your locale who would be willing to meet with you. You would want to find someone who can sense energy (whether by sight, touch, whatever) so the person can give you feedback on what results you're having.
I do cast circles sometimes without moving at all. I begin, as always, by centering then grounding. Once that's well established, I focus the energy at my center, then gradually expand it into a sphere (pulling energy up from the Earth, not draining your body!). When the sphere is as large as I want (the size of my circle), I anchor it into the floor (and sometimes walls).
As for calling the Elements, years ago a friend and I led a coven briefly. The friend co-leading with me is very much not into formal ritual. So, instead of calling the elements as presences at the quarters, we performed the following "Sensing the Elements" meditation to evoke the elements from within the participants.
ring bell: "Hear the Air."
light candle: "See the Fire."
sprinkle salt into bowl of water, then sip: "Taste the Water."
pick up stone: "Touch the Earth."
anoint with oil: "Smell the Essence."
When doing this as a group, we passed the bell around. After each person rang it, s/he could say something brief about what s/he needed from Air that night.
We then passed the lit candle around, again people could say something.
We then passed the bowl of salt-water, each person sipped, then could say something.
We then passed the stone, each person held it, and could say something.
We then each anointed the next person (usually a pentagram on the forehead), consciously blessing her/him.
[This is a very effective way to actively include everyone in the circle. No-one will feel like an audience while someone else performs the ritual.]
Thanks to
amandamagick for helping me develop the "Sensing the Elements" meditation.