In 2006 we had a customer call us about a Crossbow for his wheel chair. The customer was paralized from the neck down in a car accident. He loved to hunt and had a setup installed on his wheel chair.
He purchased a Excalibur Exocet from us and mounted it on his wheel chair. He was able to aim the crossbow and shoot it with his mouth.
He killed two does in one day the first year he went out. He sent us a couple of pictures. We have them posted on our website.
Scroll down on the picture gallery and you'll see him with the bow mounted on his wheel chair. I think I was just as excited as he was!
http://www.outdoorsexperience.com/gallery.html