The Best Active Office Chairs

A longtime dancer tests chairs designed to give the desk-bound a subtle workout, including the Buoy, ErgoErgo, Mogo, muvman and swopper.

FORGET TRADITIONAL task-chair luxuries like lumbar supports or even armrests. These days, health-conscious and fidgety computer users are opting for Spartan stools known as "active" or "dynamic" seats. Bucking conventional wisdom, these chairs' primary selling point is instability: They move when you sit on them—tilting, swaying, rocking—which forces you to engage your core abdominal muscles and continually shift your weight. Although similar in function to the yoga balls preferred by some daring office workers, these stools don't roll out from underneath you while you compose an email—and most look slightly more professional.

For an expert's assessment of these new-breed seats, we called upon Renee Robinson, a longtime member of Alvin Ailey American Dance Theater, who retired last year after three decades with the company. Ms. Robinson, who is working on a series of children's books, expects to be sitting far more than she had been—so she was enthusiastic about the test drive. "To keep the joints supple and the circulation and lymphatic system working, the body should be in motion," she said. We hauled a few chairs to the Alvin Ailey studio in Manhattan and set them in front of a desk with a keyboard. Here's Ms. Robinson's take on five models for the upwardly—and laterally—mobile.

1. Most Comfortable - aeris muvman
This lightly padded seat-on-a-stick was Ms. Robinson's favorite. "You may look at this stool and think, 'There's no way that teeny little seat will hold me,'" she said, "but the big base gives it a sense of solidity. I'm feeling a little more grounded in this one, even when I lean way forward." She explored the seat's mobility by shifting her pelvis in various directions as she sat, then reached down and raised the seat, which had been keyboard-height, until she was almost standing. "As a dancer, I'd probably want more movement possibilities," she said, "but then again, I like that the range of motion isn't so enormous that it becomes distracting."  


4. Cushiest - aeris swopper

The cartoonish swopper looks like a giant spring with a cushion on top. Both its height and the tension of its stem are adjustable, so sitters can increase the stool's range of motion as their abdominal muscles strengthen. "I like this from a dancer's perspective because I can lean way over and give myself a stretch without standing up," Ms. Robinson said. "And it's sturdy. You don't feel like you're going to wobble. Nothing is going to come apart." Ms. Robinson was also a fan of the soft red cushion. "I like the softness, how it doesn't dig in."