FDR did a lot to conceal his disability. Ableism was really fierce at the time, and he wanted to project vigor. It was heroic, and clever. Aides would carry a standing FDR to a podium, holding him up by his powerful arms. And then he’d use those arms to stay up while he spoke.
US Naval Institute Proceedings in the 30s once made reference to a cruiser (Houston, IIRC) being frequently used by FDR as a transport because it had special “Presidential fittings” and I’ve long suspected that was code for ramps and the like.
A clever trick was to arrive at a crowd to give a speech in a car, drive the car up a ramp with a microphone, and have him give the speech from the car. It gave the impression he was in a hurry to fix things. Political cartoonists obliged, and frequently depicted him running.
He concealed it, though not completely.
But that’s beside the point. He was in a wheelchair and, despite the ableist framing of the Economist, he was the greatest U.S. president ever.