You Asked for It
November 2002

HI Sharon:
I enjoy your newsletter. It is professional in its look and approach and gives very useful information. I have run across some articles recently on fit balls and sit balls to use instead of chairs at a your desk. I often work out with my exercise ball and love it.

Could you comment on exercise balls as chairs in your next newsletter.

Thanks

Terry Mack
Director of Training
Common Sense Solutions
Home of "The E-Business Tutor"

(I also had a phone call last week from a woman who had been told to remove her "exercise sitting ball" from the office because it posed a safety hazard).

The concept is that an exercise ball is an unstable object, so sitting becomes a dynamic activity. A dynamic activity uses cyclical contraction of muscles which promotes circulation to, from and within the muscles. This compares to using an upright and unsupported sitting posture which is a static activity - one which actually restricts circulation to the muscles, causing a build up of lactic acid and other byproducts of the muscle contraction.

The first exercise balls used for sitting were simply large balls. The user sat on them with their legs widely spread and their feet hooked around the sides of the ball, with their toes or feet on the floor. The lack of back support and bouncy-ness of the ball required continuous but varied contraction of the back muscles. The wide leg stance and dropped knees promoted circulation from the lower extremities through the groin. As with kneeling chairs, when used for long periods of computer work, I would expect the user to gradually assume a hunched upper back posture. From a safety issue for the user, I don't have as much concern about the use of an exercise ball as I do about kneeling chairs (which lock in the legs). There remains however, a bit of a safety issue for people around the primary user. The problem is that floors are rarely flat - that is why there are levelers on the panel and desk legs! So, when not in use, the balls tend to roll around, creating a tripping hazard.

More recently I saw a sit ball that was set into a frame with wheels and a lumbar support. The ball itself was comfortable to sit on and my knees naturally separated and fell down and to the sides - definitely no skirts allowed. The lumbar support was height adjustable, but only within a small range. The idea was that a heavier person would sit lower on the ball and lighter person would sit higher - so a lot of lumbar adjustment wouldn't be necessary. There was no upper back support however. That means no opportunity to relax the upper postural muscles. You could lean back against the lumbar support, but still had to hold a static contraction of the upper muscles. The other problem is that the sit balls locate you higher at the desk. If your keyboard was already too high, this might be a way to accommodate better arm position, but you would still lean over the desk for reading and writing tasks. In most offices, using a sit ball would require considerable changes to the desk heights.

The interesting thing about the sit ball in a frame, is that it defeats the purpose. By making the ball itself stationary, it is simply an oversized chair with a bit more bounce in the seat pan. Add to that the lack of adjustability in the lumbar support, lack of upper back support and need to raise all the furniture to accommodate it. Overall, it is not a device that I would recommend for anything other than a change in posture. For concentration and comfort, I always recommend a chair with good back support.

Feedback

"Hi Sharon,

I also did not recommend exercise balls for use in our facility. I was concerned with the safety warnings from the manufacturer (due diligence) and a clear overstatement of health benefits. I made a case for the use of [regular] chairs and the options available and the use of these options regularly. I also made a case for standing when there's opportunity to do so.

All this while I was up against physiotherapists and doctors, who have no idea of the ramifications of their opinions, who present the idea of items such as exercise balls to be applied in a Regulated workplace where there are Unionised staff. It would be nice to be a workplace where "experimentation" is freely available and without consequences but I for one have not known many of these workplaces to exist.

In addition, the "research" presented to me on the health benefits was not from scientific merit yet it's mere existence is justification to the layperson. I believe the Ergonomist has a large role to play to help populations understand the issues of alleged "health" improvement devices as some are very beneficial but many are smoke and mirrors, at least when their literature is stretching the possible benefits claimed."

Corporate Ergonomist

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