Before audience members at the April 20 opening of Broadway’s “The Cripple of Inishmaan” could congratulate Daniel Radcliffe on his performance, they had to get a stupid question out of the way first.

The actor’s physically demanding performance requires that, every time he sits onstage, he keeps one leg raised in the air as one of the marks of his character’s disability. Isn’t that painful after a while?

Not so much, according to Radcliffe, who likened the physical elements of “Inishmaan” to a demanding dance number in a musical like “How to Succeed in Business Without Really Trying” (in which he also starred on Broadway).

“Someone said to me, ‘Well, when you’re at home, do you sit with the other leg in the air, just to balance it out?’ ” he said at the show’s opening party at the Edison Ballroom. “And I thought, ‘No, but I probably should!'”

Radcliffe, like everyone else involved in the production, is loving how much more vocal and audibly reactive American audiences are compared to auds in London, where the production premiered last year. “It’s gorgeous,” Radcliffe said. “We don’t really ooh and aah in London. We don’t gasp.”

Director Michael Grandage said he and the cast relished the opportunity to go back and work on the play after their initial go at it on the West End. “Daniel has certainly continued to work on it,” Grandage said. “His performance has gotten deeper and darker.”

It was Radcliffe’s idea to do an Irish play with Grandage, in part because Radcliffe’s father is Irish and in part because he’d never done an Irish play before. “He likes doing things he’s not done before,” the director said of the thesp. “He likes going out of his comfort zone.”