I love my fitness ball! It makes a great, affordable tool for modifying pilates exercises, improving balance, and ups the stability challenge of anything done on a the typical bench in the weight room. And of course, lots of people are using it as a chair. So here are a few tips, if you go that route.
First of all, if you can't sit on it, and stay on it, then don't attempt to use it as your chair at work, for 8 hours. I read a few articles about using a ball as a chair and that point was brought up by several worrywarts. No, seriously, if you can't balance on a ball with your feet on the floor, we should talk. Your core muscles need a wake up call.
Sizing: If you want to use a ball as a chair at a work station, you'll need to get a ball large enough, so that when you sit on it with your feet on the floor in front of you and your knees are bent at a right angle, your hips should be slightly higher than your knees. Also you should sit high enough so that you can bend your arms to your work station/keyboard with your neck relaxed, shoulders down and wrists slightly lower than your elbows. (that drawing is not to scale, but you get the general idea, right?)
A point not everyone is aware of. If you sit on a ball for hours and hours--well actually if you sit for hours and hours anywhere-- but especially on a ball, be sure to engage your pelvic floor muscles. The ball is domed-shaped and as you sit on it, your pelvic muscles can relax. Sounds good, right? But too much of a good thing can be, well, bad. Weak pelvic floor muscles can increase the chances of hip and low back pain and even incontinence.
Clients ask me what I think of those chairs that hold the ball.
Now I know a lot of folks love them. And if they make you feel better, then by all means go for it. But personally I see the chair as a gadget that takes a ball, with all of its benefits, and turns it into a glorified seat cushion. When the ball is used alone, it challenges balance, stability, keeps you on your toes, so to speak because you can't slouch like in a regular chair. But the chair, takes all that away, because it's now stabilizing the ball and all you have to do is sit on it. Granted, the dome shape is a bit less stable than a regular chair seat, and the wheels make it easier to roll around the room. But like I said, you get more for less with just a ball.
Lastly, if you want a ball that you can move around the room on, then maybe a Hippity Hop is what you need. (I think I saw some in the window at PollyWogs.) I have one! You can sit on it, then when you need to move from your desk to a file cabinet you can grab the handle and hop over to it and back. Unfortunately, a lot of employers have banned the ball at work. So I'm sure this would just send HR run screaming from the building. Oh, the joys of protecting ourselves from getting healthier. . .
So, should you get a ball? Should you use it as a chair? I rank the ball itself a High Five! Using it as a chair is just one of the great ways to use it. Should you get that chair contraption?Hhhmmmm. . . I rate it at a two on the 1-5 scale. Use-it-if-you-like/have-it-but-don't-bother-if-you-don't.