Bear in mind that there are options like this out there that can help the impared with their gaming. In this case especially, by offloading the WASD / Arrow keys to a foot pedal, it makes a lot of action and FPS games doable. I don't know the specifics about this situation, but I talked with a gamer in the past who lost his left arm, and a pedal like that with a mouse like this made him just as capable as anyone else.

Here's my set up after loosing 2 fingers on left hand: Stinky gaming footboard, UtechSmart gaming mouse, and Logitech Gaming pad with joystick for wasd The G-13 has been the biggest help for me in FPS, but for racing games it sucks, I have to switch back to the keyboard. I don't use the footboard as much though. Hope one of these or similar helps bro.

Wouldn't this be better?