What made the ‘Reemski’ dance go viral? Its Brooklyn creator says it started offline.

Warm up those knees and quads. You’ll need them to try a new dance that’s going viral in New York City.

It’s called the “Reemski.”

The dance involves rolling your shoulders in a circular motion while taking tiny steps and moving your hips side to side, like a downhill skier.

It’s already been turned into a meme about the MTA and a popular joke about how Jesus walked out of the tomb, and has reached one of the most influential people on Twitch: Kai Cenat. Some clips of people doing the dance have been viewed over a million times on social media platforms.

It’s typically performed to the song “Fisherrr,” by Bronx rapper Cash Cobain in collaboration with rapper Bay Swag.

But the creator of the “Reemski,” aspiring rap artist Kareem Gadson, said it can be done to any song. His favorites include Sexyy Red’s “Get It Sexy” and Travis Scott’s “FE!N.”

Like iconic dances before it — the Chicken Noodle Soup, Harlem Shake, Shmurda (sometimes called the “Shmoney”) and others — the Reemski started in the Big Apple.

“I just got tired of doing the dances that I was seeing out here,” Gadson said. “So I just decided to do my own.”

Gadson, who lives in Brooklyn, said the dance is called the “Reemski” because the leg movements look like someone skiing downhill. He said he’s been doing it since 2016 at parties but it only recently took off online when people started posting clips of him dancing.

“I like that it doesn’t have anything to do with violence,” he added. “It’s got a lot to do with just having fun and enjoying yourself.”

Cash Cobain said the timing of the dance taking off is “perfect.”

“And it helped boost my song too, so of course I’m gonna love the dance,” he said.

So how do you do the Reemski?

Gadson said the first step is to turn to sway your body to the right, pop and lock your arms, then do the same thing on the left. Whenever…