The American Journal of Occupational Therapy published research on the use of stability balls in the classroom. Eight children who were highly likely to have attention deficit hyperactivity disorder were observed 3x/week for 12 weeks while using stability balls in the classroom. When the data was analyzed it revealed that while using the stability balls the following was observed: "increased levels of attention, decreased levels of hyperactivity, and increased time on task and in seat or on ball". A questionnaire that the teachers completed indicated that the teachers preferred the stability ball.
You can read the complete study here.
Reference: Fedewa, A. L., & Erwin, H. E. (2011). Stability balls and students with attention and hyperactivity concerns: Implications for ontask
and in-seat behavior. American Journal of Occupational Therapy, 65, 393–399. doi: 10.5014/ajot.2011.000554