“Flex Is Kings” explores the phenomenon of a flashy Brooklyn street dance and various performers and organizers who have embraced it. (Kasia Grabek)

Flexing is a sight to behold. The competitive dance form involves hanging from bridges and flipping off balconies, throwing flaming flash paper and donning weird masks. One dancer in the documentary “Flex Is Kings” secretly holds a bird in his mouth while he performs until, suddenly, he opens up and lets the little guy fly. Those ostentatious maneuvers — which are mixed in with body movements that recall popping-and-locking and other forms of street dance — are what set flexing apart. And for some performers in the East New York borough of Brooklyn, where the dance was born, they might be the key to a better life.

In “Flex Is Kings,” directors Michael Beach Nichols and Deidre Schoo follow various dancers and organizers involved in the movement. Some had been involved in gangs and drugs but have chosen creative pursuits that don’t pay over potentially lucrative but illegal ones. In fact, in one scene, Flizzo, one of the film’s main subjects, sells tickets to a big dance competition on a street corner where he says he used to deal drugs.

Portly and boisterous, Flizzo might lack exacting footwork, but he more than makes up for it in creative flourishes that get a crowd on its feet. (He was the mastermind of the bird stunt.) The movie’s other main subject is Jay, a lithe and soft-spoken talent who is recruited by Brooklyn’s experimental Company XIV to star in a version of “Pinocchio” that goes on to debut at Edinburgh’s renowned Festival Fringe.

The movie’s great strength is the way it captures these dancers, sometimes in slow motion, as they contort their bodies in ways that don’t seem possible. When it comes to the narrative, though, the movie struggles a bit. Although Flizzo and Jay end up being the two predominant threads, the documentary starts out with no apparent focal point, meaning we don’t get to know these characters very well, especially the meeker Jay. His story is especially inspiring, but it also has potential for drama. He is, after all, a freestyle dancer from the streets who is working for the first time with a professional dance company where precise choreography is important. But we don’t get many of the details of what that push-and-pull feels like beyond the fact that it exists.

In the visual realm, Nichols and Schoo know what they’re doing. The movie culminates in expertly interwoven shots of Flizzo vying for the title in the annual Battlefest dance competition and Jay’s debut in Scotland. It’s an uplifting finale, even if both men don’t get exactly what they want.

Overall, it doesn’t always seem like the directors knew where they were going, but they ended up in the right place.

★ ★

Unrated. At the Angelika Pop-Up at Union Market. Contains language. 83 minutes.
A question-and-answer session with director Michael Beach Nichols will follow the 8:30 p.m. screening Saturday and the 2:30 p.m. screening Sunday.