Is Sitting On An Exercise Ball At Work A Bad Idea?
What are you sitting on? Using exercise balls at work
Fitness Ball Is Not Suitable As A Chair
Should I Sit on an Exercise Ball at Work?
Ask Well: Do Ball Chairs Offer Benefits?
If anything they may increase lower back problems.
However, I did come across this:
Researchers have determined that increasing the seat angle produces reduced muscle activity in the back and reduces disc pressure. Leaning back at an angle between 110 and 120 degrees decreases disc pressure to even lower than that in standing. In addition both lumbar support and the use of armrests have been found to always result in reduced disc pressure. Muscle activity is reduced even further with a wider seat/backrest angle.And this:
As a result, chairs have been developed with a variety of back rests and improved adjustability, including seat-to-backrest angles. These features assist the sitter to achieve optimum posture. Modern approaches to chair design reject the concept of a fixed 90 degree sitting posture, in favour of a more dynamic posture centred around an 'open' trunk-thigh angle of 105 degrees or more. A variety of chairs provide this dynamic posture, such as dynamic chairs (adjustable seat/backrest angle), 'sit/stand' chairs and 'sit/kneel' chairs.
The [United States Army Public] Health Command also explains that sitting in a chair in a reclined position significantly eliminates disc pressure in the back.