The use of ball chairs (or FitBalls, Swiss Balls, Physio Balls, Exercise Balls, and any other name they may go by) are recognizable in your local gym or physical therapy shop, but lately, they are appearing in the workplace as a replacement for an office chair. Below are a variety of opinions that have been shared among members of the Ergoweb community

According to Jeanie Croasmun, writing in The Ergonomics Report™:

The intent of the ball chair developers was laudable: to take an item that seems to be beneficial in an area of health care (rehabilitation and strengthening/wellness) and apply the same principle to the office. But just like a hammer might be a valuable tool for some tasks (hanging a picture), in others (washing dishes) it’s useless or may do more harm than good.

The exercise ball might be great for strengthening and toning in the gym or at home, but it can’t compete with a truly ergonomic chair for long-term sitting in an office environment.

And Jeff Pajot, writing from Canada, in the Ergoweb Forum:

Exercise balls are not recommended for prolonged office sitting.

• Sitting on the exercise balls with no trunk support and the constant trunk movement certainly does activate trunk musculature and therefore aids in maintaining muscle tone. However, since the muscles shorten during contraction, there is a huge compression placed on the intervertebral discs. Prolonged compression is contraindicated, especially during sitting since the pelvis is rotated forward which flattens the lumbar lordosis adding a further compressive penalty to the discs.
• I don't know if it is published, but Dr. Stuart McGill (University of Waterloo) told me that the EMG in all trunk musculature goes through the roof while sitting on the exercise balls. In particular, the Quadratus Lumborum muscle is highly active and it places a high compressive force on the discs.
• A modified version of the exercise ball is the"Swopper Chair". It is a stool with a weighted concave base. So, while sitting on it, you are a little off balance like the exercise balls. Like the exercise balls, the trunk musculature is highly activated. I was asked by a local distributor to perform a quick evaluation of the Swopper chair and I sent a response indicating a risk to back injury with prolonged use.
• Furthermore, in the morning since the spine is elongated due to lying down for eight hours after sleeping and the intervertebral disc space is larger, the spine is much more unstable. Lifting and excessive spinal movement in the first couple of hours in the morning is not recommended. Therefore, an exercise ball or similar device should probably not be used first thing in the morning.

John Ridd (UK), in the Ergoweb Forum:

In a consultant capacity I have and would recommend against allowing these into the workplace - other than when there has been a specific (and probably written) request from a medic/physio or the like. Apart from the spinal risks already mentioned there are general health and safety risks to consider; the potential for injury, if the user were to become so unbalanced as to fall off the ball is enormous, and I can only imagine the awkward questions that might be asked after such an event. In the UK, one of the criteria that office seating has to satisfy, is that it should be 'stable'!

In another post Ridd continues:

I'm sure the rehabilitation benefits of these balls are significant and one always has to be careful of questioning the advice of an individual's treating professional; however, my non-clinical experience has been that the described benefits do not outweigh the potential causes of concern for the use of these products in the office environment, and that in general I agree with your view that a good office chair is likely be more appropriate. There are too many possible dangers for the user and for colleagues in normal office situations; it does not need an ergonomist to describe the effects of any loss of balance.

Shona Anderson (Canada), in the Ergoweb Forum:

I have had many questions about Ball Seats or "FitBalls" over the years … In my opinion, they are good for short periods of time, while the person can maintain a neutral spine and strengthen his muscles while maintaining balance. However, many people fatigue quickly and then they slump or change their posture to one which is not as good for the spine. At this time, I believe they need to switch to a chair that offers them good back support until their muscles are no longer fatigued and then they can switch back to the ball.

David MacFarlane (Australia), in the Ergoweb Forum:

There was an interesting discussion about this topic in the Aus Ergo discussion forum last year that was very illuminating for people like myself who have had little experience of the “gymnastic-ball” chair phenomenon. We were basically told that they can be used for therapeutic purposes with adequate supervision but rehab advisors said that when they are often asked to support the use of a fit ball as a chair replacement, they have usually declined for the following reasons:

• You can slump as easily on a fit ball as a chair
• The balls have a tendency to roll out form under the person as they sit or stand
• Fit balls are not height adjustable potentially and this can result in poor upper body postures
• For dynamic work tasks an additional consideration is the instability of the balls as inappropriate postures can result (and there is a risk of losing balance and falling off).

Andrew L. Concors (USA), in the Ergoweb Forum:

As both a PT (as physio are referred to here) and ergonomist I'd have to recommend against the use of the ball exclusively, primarily for safety reasons. First, the fitball is not primarily designed to be a sitting surface while chairs are. I've had one patient's ball burst on her while performing exercises at home. Secondly, the balls have a tendency to roll even when placed in a ring, causing a potential for the employee or co-workers to trip and fall. Without a specific reason beside the one given and research to back it up I would consider the recommendation as "armchair ergonomics" (no pun intended) given by a well intentioned healthcare practitioner. That being said, the ball may be an option for short-term use and a very inexpensive one at that (they can be purchased for as little as 10 euros). I hope this helps,

And I wrote, in the Ergoweb Forum:

• They are not ergonomic seating devices (e.g., they have no user operated adjustments).
• A ball is inherently unstable, and therefore introduces a safety hazard in the workplace.
• Using a ball to strengthen abdominal and other trunk muscles, often the reason for which they are touted, is best done under the guidance and direct supervision of a medical professional.
• As an employer and in my consulting activities, I would only allow one for workplace use with written directions or prescription from a qualified medical professional (even then I would remain concerned with liability).
• The people who seem most enthusiastic about their use and efficacy are often those that are selling or promoting them, not the users who end up sitting on one for 8 or more hours a day.
• There are other chair designs that may accomplish the same posture and trunk toning goals as the ball, but also provide adjustability and stability (two important features for something to be deemed "ergonomic").

So, for all the good they may do in the local health club or physical therapy shop, you might want to think twice before outfitting your office with these inexpensive “miracle cure” devices. They can offer certain advantages when used for a prescribed period of time in a controlled use environment, but they likely present more risks than they’re worth when used as an office chair.