Never underestimate folks with a disability. Someone in crutches may be able to swing a crutch to sweep out an opponent's legs. There are folks who RACE wheelchairs.

If you are perceived by your enemies as disabled that may even allow you to maneuver undetected into a position of advantage.

A person that can neither speak nor walk could turn out to be that fearsome blacksmith, machinist, and armorer whose creations strike fear into Nazis and fill their pants with shit. Probably they'd be ignored even in house to house police raids. Disabled armorer one, cops zero.

In New York City their used to be a one-legged bike messenger who could ride with the best of them. He lost his right leg in the process of saving a child about to be run over by a bus. Never one to sit and mope, he built a fixed gear bike with the drivetrain on the left and no right pedal. Note that a fixed gear is far easier to ride with only one leg as the pedal is guaranteed to come back around. He used a skateboard for a hand truck, and bungeed the crutch for his bad side to the top tube of the bike.

Yes he had knee issues with one knee taking the power of a leg built to double power. No he didn't let it stop him