A modder has made a Wii Nunchuk mod. It was designed for a good friend of the modder, who's arm only extends a little below the elbow. The design for the Nunchuk is intended to be used at the elbow with the joystick resting on a knee. The two buttons from the Nunchuk were removed and placed on the side of the Wii-remote where they can be easily pressed with the middle and index fingers.
To view this mod project, click on link below and go to "Projects". On the right hand side, you'll see "Special Projects" and click on the "Wii controller" link.