Learning about acccessible gaming and the controllers that help people with disabilities join this popular activity isn't always easy. In an effort to provide introductory information on what choices one might find, consider these links below as starting points. Please note: the links below are not formal recomendations of these products or vendors.
1) Puff controller for quadriplegics: http://www.quadstick.com.
2) Optical tracking controllers: http://www.naturalpoint.com.
3) Voice activated controllers: http://voiceattack.com/.
4) One handed controller: http://www.oneswitch.org.uk/art.php?id=19.
5) Wireless head controlled mouse: http://www.orin.com/access/headmouse/.
6) Footboard controllers: https://www.amazon.com/Stinky-Gaming-Footboard-Foot-Controller/dp/B00EOPT5ZS and https://www.3drudder.com/.
7) Programmable multi function control panel: http://www.chproducts.com/Multi-Function-Panel-v13-d-724.html.
See also this CTD posting on a Disabled Gamer Manual reviewing mainstream controllers: https://www.ctdinstitute.org/library/2018-03-07/disabled-gamers-manual.
See also this Reddit "Disabled Gamer Group" for more current information and discussions on a multitude of disabled gamer topics: https://www.reddit.com/r/disabledgamers/.