LIARS PERFORMANCES ARE typically acrobatic affairs.

On stage, towering frontman Angus Andrew gets physical — he writhes about, hurls himself from the top of amplifiers and tangles himself amid the microphone cords while guitarist Aaron Hemphill and drummer Julian Gross pound out scrappy and spooky post-punk.

But when Liars perform at 9:30 Club on Tuesday there’s a good chance Andrew will be doing it from an armchair.

“It’s an interesting way to do a show, I’ve never done it in the past,” said the singer. “It certainly adds more drama.”

It’s hardly artistic sensibility that’s keeping Andrew confined to a chair, though. A week prior to the band’s three-and-a-half-week tour, Liars announced via their MySpace page that Andrew had thrown his back out while trying to pick up a pillow at his Los Angeles home.

“Getting up and sitting down is a bit of an ordeal for me,” said Andrew. “It’s made me a bit more like and old man — hunched over, drooling — it’s a different window into our performance.”

Maybe the wear and tear of cavorting around arena-sized stages has finally taken its toll. Liars recently completed a tour supporting well-attired New York mope-rock band Interpol, and that band’s mega-dome-style billing allowed Liars a little more room to jump around than they’ve had in a while.

“It required more grandioseness,” said Andrew. “But we are that — we are grandiose.”

It’s also possible that Andrew might have gotten a little too involved in trying to freak out Interpol’s buttoned-up fans.

“We wanted to make sure that the crowd knew that we enjoyed making mistakes — to remind them that not all bands play the same way,” said Andrew.

Whether this resulted in enjoyment or alienation isn’t a huge concern to Liars.

“There are different definitions of connection,” said Andrew. “I think we connected with people in a strong way — although it may have been distasteful. We shocked them out of their comfort zone. We maybe weren’t what they expected. Hopefully we rocked some people’s worlds in a way that opened their eyes. It wasn’t hard to shock them — I mean, Interpol are so clean-cut.”

According to Andrew, Liars’ dedication to unpredictability and sonic creepiness is a reflection of our unpredictable and creepy world.

“It’s a sign of the times, really. Since we’ve been a band we’ve been living in this culture of fear and paranoia that’s pervasive in American society,” explained the singer. “It’s difficult to make music that escapes that — which is why our work is so uneasy and fractured. Right now a lot of people are making hippie music, and I find that difficult to swallow — it’s not the ’60s.”

But however much he doesn’t like it — for now at least — Andrew will have to take things sitting down.

» 9:30 Club, 815 V St. NW; with No Age, Tue., 7:30 p.m., $15; 800-955-5566. (U St.-Cardozo)

Written by Express contributor Aaron Leitko

Photos by Joe Dilworth