Choreographer Ralph Lemon has spent the last nine years trying to make dancers do something impossible: disappear.

Not literally, of course, but rather on "an energetic, physical, kinesthetic level," Lemon says. What does that look like, exactly? In his word: messy.

"The body is moving at a very high level for a long period of time, going in as many directions as it can, simultaneously," Lemon explained in an interview last week during his company's residency at EMPAC. "There's never a still image — it's a moving blur."

"4Walls," Lemon's most recent exploration of continuous motion, is on stage Friday at 8 p.m. and Saturday at 4 p.m. at EMPAC.

Lemon has been pushing boundaries of one sort or another for more than 30 years. His body of work addresses social, political and identity issues, using frameworks that meld dance and visual art, text and film, theatricality and pure movement. He studied literature and theater arts at the University of Minnesota, in his hometown of Minneapolis, and danced with the innovative composer/choreographer Meredith Monk before founding the Ralph Lemon Company in New York City in 1985.

The company disbanded a decade later, but Lemon has continued to choreograph, direct and collaborate in multiple mediums through his cross-disciplinary company Cross Performance. His 10-year "Geography Trilogy" project was influenced by his travels in Africa and Asia, and by the ritualized structure of Buddhism. Lemon also wrote two books to accompany the trilogy, which includes the dance/theater works "Geography," "Tree" and "Come Home Charley Patton." Patton was a great Delta blues musician born in Mississippi, and the piece references the segregationist era — including a section in which Lemon is sprayed with a fire hose, as civil rights protesters were in the 1960s.

The final three minutes of "Come Home Charley Patton" — a high-speed, high-energy tangle of spins, falls and collisions — marked the beginning of Lemon's fascination with the idea of "formless dance." He expanded the sequence for his 2010 work "How Can You Stay in the House All Day and Not Go Anywhere?," which combined visual art, text and video of past performances.

In "4Walls," Lemon weaves two sections of video from that 2010 performance with two new solos, danced by Gesel Mason and Darrell Jones. Each dancer engages in nonstop movement for about 20 minutes, a feat of endurance they've prepared for with rigorous training.

"You're watching a body trying to continue doing something extremely difficult for it to do," Lemon said. "As with any extreme sport, there's a natural tendency for the body to break down. The unanswerable question is, How far can one go? What happens after one hits that wall?" (He's very careful, he notes, to make sure that what he's requesting of his dancers is reasonable, or at least "healthily unreasonable — it's important that no one gets hurt.")

To give the dancers something to hang on to in the maelstrom, Lemon created a movement narrative of sorts: a series of physical "tasks" they must complete. He describes them as "stations" in time and space that mark the unfolding of the work. For the most part, however, the dance is not choreographed in any traditional sense of the word.

"It's dancing that's beyond shape or style — dancing that's beyond dance, as I know it," Lemon said. "There's something infinite and primal about it. It's a metaphor for life itself — things break down, collapse and die, and yet life goes on."

Tresca Weinstein is a freelance writer.