If you're looking for a seating alternative you may have learned about the yoga ball chair. The thought is that if sitting on an exercise ball chair for 10 minutes is good, then sitting on an exercise ball chair for 4 hours is better.
Unfortunately, although there are benefits from sitting on a ball chair such as stabilizer muscle recruitment and strengthening, it's just too difficult to sustain that kind of muscle activity for very long periods of time such as that required at work.
It may be beneficial however to sit on a stability ball chair for shorter interrupted periods of time. Perhaps at your desk at home, or in your kids room for doing homework.
If you have a history of back pain or disc injury it is best to consult your family physician or physical therapist prior to purchasing a yoga ball chair. A fitness ball may be recommended by a physical therapist to treat a condition. In these cases the use of the ball as seating should be prescribed in a treatment or rehabilitation plan, along with recommendations about the duration of use and any other treatments provided.
A 1992 study done amongst 310 children aged 8 and 12 used muscle testing and balance testing to determine if using a yoga ball chair throughout the school year would have a positive effect. Results of this research suggest a possible effect of the seating on the back and abdominal muscles.
Amstad H, Bachlin A, von Arx N. ball or chair as seating arrangement in the classroom. A prospective study. Schweiz Med Wochenschr, 1992 May 23;122(21):811-6.
Another study done in 2006 examined muscle activation in 14 muscles amongst a group of 15 men sitting on a stability ball versus a wooden stool. Muscle activity and spine position were used to model spine load and stability. They found no difference in muscle activation profiles of each of the 14 muscles between sitting on the stool and ball. They conclude that prolonged sitting on a dynamic, unstable seat surface does not significantly affect the magnitudes of muscle activation, spine posture, spine loads or overall spine stability.
McGill SM, Kavcic NS, Harvey E. Sitting on a chair or an exercise ball: various perspectives to guide decision making. Clin Biomech (Bristol, Avon) 2006 May;21(4):353-60.
A study using children with attention deficit hyperactivity disorder found that using a an exercise ball chair resulted in better in seat behaviour and improved productivity of legible writing
Schilling Dl, Washington K, Billingsley FF, Deitz J. Classroom seating for children with attention deficit hyperactivity disorder: therapy balls versus chairs. Am J Occup Ther. 2003 Sep-Oct;57(5):534-41.
We can conclude that using an exercise ball chair in the class room is beneficial in terms of the following: