If dancer Gus Solomons Jr. was hoping choreographer Robert Battle would take it easy on him in reshaping his comical "Two" for the American Dance Festival, he blew it from the get-go.

"Gus made a fatal mistake when he was warming up and went into the splits," Battle said of the 69-year-old Solomons.

"I do the split when I dance it," Battle, 35, said of the short piece. "But I wasn't going to bring it up. I said, 'I'm not going to push it.' "

Then he saw Solomons in his split on the floor, and he threw away his kid gloves.

Solomons and "Two Redux" partner Carmen deLavallade, 77, make it their business to defy expectations. While many of their peers retired from the stage decades ago, these two forged on, working with top dance, theater and opera companies around the nation and eventually forming their own troupe called Paradigm.

They're not the first company to embrace old dancers as viable performers. Modern dance -- unlike the more rigid discipline of ballet -- has always had a place for dancers of varying abilities and disabilities. But deLavallade says dancing into old age is still a foreign notion to many dancers, and that baffles her.

"Some of these kids are stopping at 30, for crying out loud," she said in a phone interview. "That's when you just start going. The body is fine. You have practically all your faculties at 30. At 40, 45, people are still strong. But they just drop it, saying, 'Oh, I'm too old.' "

DeLavallade intends to dismiss the notion of "too old" when she and Solomons share the ADF bill with Battle's Battleworks company and fellow young bucks Larry Keigwin+Company.

Battle's five-minute "Two Redux" is set to a Vivaldi piece and to Donna Summer's disco hit "Last Dance." Solomons and deLavallade will also perform a new ADF-commissioned dance Keigwin created for them. It's called "Mirror Image," set to Billy Idol's 1981 hit "Dancing with Myself."

Rehearsals have been exhausting and sometimes trying, Solomons says. While some choreographers treat Solomons and deLavallade too gently because of their age, this pair pushed them too hard, with fast and demanding movements.

Paradigm tends toward a subtler form of expression, says Solomons, whose knee replacement and age-related aches shape his movement vocabulary.

"What you have is economy, the notion that you don't have to work so hard, partly because you can't but also because you don't need to," Solomons says. "You have the experience of a lifetime of dancing that informs how you give expression to whatever it is you're doing."

Battle has given Solomons and deLavallade free rein to make their mark on his dance, and he is curious to see the result. But he says working with them has made its mark on him, too.

"It stretches you to push yourself in a different direction and to be more clear with less movement," Battle says.

"It was interesting to have to not rely sometimes on the shock value of dancers flinging themselves wildly and get to the point: 'What movement is totally essential to the statement of the work?'" he says. "So it made me think differently about what I was doing, and I think that has influenced my work a lot."

DeLavallade says she can't imagine ever abandoning dance. Her joints may be less flexible than they once were, but she will always be able to stretch her perspective.

"I have to be honest with myself and figure what are my limitations, or are they limitations, or is this something I have to reinvent?" she says.

"I'm certainly not going to even attempt to try what I did years ago. I think that's folly, because I'm not that person anymore. But I am somebody else."