Resist-A-Balls

Does anyone have any information, experience or literature on the use of "resist-a-balls" (large, inflatable vinyl exercise balls) in the workplace, specifically, as an alternative to a chair? We have have had a request from an employee wanting to use one at their computer workstation instead of their "ergonomic" chair.

Any feedback would be much appreciated.

Resist-a-Balls are used by some physical therapists in the treatment of low back injuries. The purpose is to help the patient gain lumbar and abdominal strength while relearning proprioception (position sense) of the trunk/pelvis complex.

A big NAY on using the ball as a seat. You may as well have the person sit in a $5.00 fiberglass bucket seat. The ball will offer absolutely NO lumbar support NOR proper pelvic positioning. The only way a person could sit with neutral spinal posture on a ball would be by actively contracting the trunk musculature while concentrating on proper posture (the purpose of the short duration exercises). This requires static muscle contraction, which becomes fatiguing in a very short time (5-10 min). The result would be a worker with a slumped, flexed posture, looking kind of goofy sitting on a big ball. This posture would create increased intervertebral disc pressures and place the spinal musculature in it's weakest, least efficient range (fully stretched). In effect, the weight of the body would be hanging on the ligamentous support of the spine - a condition to be avoided.

I could go on with a long list of negatives and can't think of one positive for use of the ball as a seat. The properly adjusted (key point) ergonomic seat is the best bet. You may do well to interview the worker to determine if there are particular problem they have with the chair. Perhaps they are not familiar with the various adjustments and how to adjust it appropriately for their size.

Think of the play toy this might become in a work setting . . . :-)

A big NAY on using the ball as a seat. You may as well have the person sit in a $5.00 fiberglass bucket seat. The ball will offer absolutely NO lumbar support NOR proper pelvic positioning. The only way a person could sit with neutral spinal posture on a ball would be by actively contracting the trunk musculature while concentrating on proper posture (the purpose of the short duration exercises). This requires static muscle contraction, which becomes fatiguing in a very short time (5-10 min). The result would be a worker with a slumped, flexed posture, looking kind of goofy sitting on a big ball. This posture would create increased intervertebral disc pressures and place the spinal musculature in it's weakest, least efficient range (fully stretched). In effect, the weight of the body would be hanging on the ligamentous support of the spine - a condition to be avoided.

Having just completed a scientific review of over 2000 literature citations regarding sitting, seating, fundamental biomechanics and muscle physiology and presenting a portion of the results at two conferences, I can categorically say that your assertions are based on some very dubious assumptions. First of all, I would like to see the proof that lumbar support is required to have spinal health, especially within the context of normal human function. The muscle fatigue you describe is an artifact of deconditioned type 1 muscle fibres that have been resting against lumbar or other back support since they first hit the couch in front of the television at age two. These tissues train very quickly and it is possible to sit unsupported and comfortable for as long as one thinks sitting should be tolerated at all (another topic). The ball would more likely stimulate dynamic variation in trunk muscle contraction since it is slightly unstable in a multitude of directions. Even if much of the work is somewhat static in nature, upright trunk posture requires less that 3% MVC to maintain. You mention disc pressure. As I am sure you know, discs gain nutrition through the regular exchange of nutrients through the endplates. This exchange is facilitated by increases and decreases of compression. Might this be an advantage of the ball with all its dynamic instability and the tendancy of users to lightly bounce?

Your comments about the danger of the slumped posture are accurate, but an office chair produces these postures in large percentages of the cases. There is even evidence that lumbar support promotes lumbar flexion bias. The contention that unsupported posture=slumped posture is one of the great legends of modern ergonomics.

Your comments indicate a cultural bias against the concept of "play" in the workplace and the fear of appearing "goofy". Such cultural biases are significant barriers to understanding normal human function as well as applying compatible techniques in the workplace.

By the way, as a result of my research, I began experimenting with sitting on a ball (price was right at $34 CDN!) while doing computer work. I have been using it almost exclusively for nearly a year. I can offer the personal anecdote of complete comfort, enjoyment and neutral spine posture. Besides that I bounce a little from time to time and if I want to do some exercise it is very convenient.