The best businesses are nimble, agile and extremely flexible. In fact, so are the most effective business owners. In part two of our small business fitness guide, learn simple strategies for staying loose and sitting up straight. Both your spine and your bottom line will benefit.

By: MATT ALDERTON

As a rule, small business owners are stiff. Their thumbs are permanently crooked from typing on their handhelds. Their hands resemble claws from gripping too tightly their computer mice. Their backs have humps from spending hours on end in a forward-leaning lurch. Even their necks, once straight, seem to have a permanent crook in them from so many client calls.

Unfortunately, when your back is out of whack, it's not just your posture that suffers. Your productivity feels pain, too, according to health expert Janice Novak, author of Posture, Get It Straight!

"We have become a nation of professional sitters," Novak says. "By stopping the slouch, supporting your back properly and avoiding the head-forward position, you will be able to work more comfortably and productively."

Naturally, when you're able to work more comfortably and productively, you're also able to work more successfully, to the benefit of both your body and your business. It pays, therefore, to straighten up. Here's how.

Perfect Posture

Whether you work from your home or from an office, chances are that running your business is ruining your back.

"You could walk into any office building all around America and see people sitting behind computers in really bad posture positions," Novak says. "Necks craning forward, slumping upper backs, rounded shoulders."

Sitting too long, she continues, is a major contributor to back and neck discomfort, as sitting puts continuous pressure—40 percent more pressure, in fact—on the muscles in your lower back, not to mention the disks in your spine. What's more, sitting in poor alignment causes your abdominal muscles to weaken, which spells trouble for that six pack that you've been doing crunches every night in order to get.

"The more you slump, the weaker your muscles get," Novak says.

In order to find your strength again, consider Novak's tips for perfect seated posture: