It is now believed that sitting on a stability ball for stretched periods of time does not change the manner in which a person sits. It only increases the level of discomfort.
As compared to an office chair, when sitting on a stability ball there are minor changes in biological responses. These changes, when combined with the increased reported discomfort while sitting on the ball indicates that sitting on the stability ball extended lengths of time may be disadvantageous.
Does Active Sitting Improve Posture? – NO
According to researchers, sitting on a dynamic, unstable seat surface for extended lengths of time does not influence the magnitude of spine posture, muscle aviation, spine loads or overall spine stability. When sitting on a ball, the contact area spreads out; this appears to cause uncomfortable soft tissue compression possibly explaining the reported discomfort.
Minimal postural sway and less muscle activity were observed during the conditions that encourage active sitting, compared with sitting on a conventional office chair. Conclusion – Active Sitting does not improve your posture.
Research has shown that the pressure on the back is increases when sitting on the ball as compared to sitting on a stool. Therefore sitting for long periods of time on the ball may lead to greater discomfort in your lower back.
It is of great importance to ensure you always have good posture while you sit. You’re just as likely to slouch sitting on a ball as you are in a chair.
In fact, slouching on the ball is even worse, as you don’t have lower back support as you do with a chair.
Research shows that that the amount your muscles work while you sit on a ball is not much different than when you sit on a stool.
If you continuously make small adjustments to stay balanced throughout the workday you may feel fatigued.
The best way to ensure your core muscles work and increase their strength is to try “active sitting.” Active sitting is sitting with “super-powered” posture.
Known hazards of using Exercise Ball as Office Chair include
High concentration levels and fatigue from continuous exercising.
Most likely to lose the initial upright posture over a long period of sitting because there is no full seat and back support
Upright postures are difficult to maintain during tasks requiring any reaching or moving around.
Employees cannot swivel or navigate around the workstation.
Getting on and off or reaching from the ball may constitute a falling hazard.
The sitting surface does not provide adequate support for the buttocks and thighs.
An exercise ball should be used as a break from the office chair, not as an all-day alternative.