Guy (Peter Arbalo) in our association averages around 180 and he's in his 70s I think. He's pretty famous for wheelchair sports in general and does a lot of clinics around the world helping others learn how to play in wheelchairs.
I'm not sure how he generates the speed he does (its not extraordinarily high or low)except he is fit. He locks the chair at the foul line and leans over a bit, taking an extra swing to build up momentum he releases the ball on the second.
Erin