Q. The Eames chair, the Aeron chair, and the Barcelona chair: what do they have in common?

A. They all cost a fortune and are uncomfortable as heck.

I remain perplexed by people who buy chairs based on reputation instead of comfort.

Nutty.

My Gymnic exercise ball has been my working desk chair of choice since the early 90s and I have yet to meet its match.

I paid $20 for mine and as of today it's $24.95.

Using one of these balls for sitting is a whole different ballgame.

Ahem.

They require "active sitting," that is, constant, unconscious movements of the back, torso, and legs to stay comfortably atop them; this is the best possible remedy for back pain and disc problems, as well as being an excellent prophylactic device against same.

In addition, venous stasis can't happen, since you are always moving just a bit, flexing and extending the muscles in your lower legs.

And, it's tremendous fun to just bounce up and down while you work.

People will think you're nuts: I know several attorneys who've tried and loved my chair but haven't put one in their offices because of its apparently frivolous nature.

Too bad!

These balls were originally developed and perfected in Switzerland, then used for decades in physical therapy throughout Europe before making their way to the U.S. about 20 years ago.

Even so, they're still rather an underground phenomenon here.

Bonus — back in the day when I was part of the academic medicine establishment, I took my extra chair out of my office and substituted a second ball: instantly, the number of people stopping by to shmooze and hang out dwindled to nearly zero.

Take it from a doctor, this is the way to go.

Helpful sizing hint: adults from 5'3" to 6' tall will find the blue 65 cm version just right.

Bonus: They come in heart-stoppingly bright colors — who could resist?