Bouncing Balls in elementary school classrooms are replacing chairs

A recent Youtube program showed students at North Beverly elementary school sitting on bouncing balls instead of chairs in the classroom. I guess this is the newest experiment to be tried on school children. The kids were having a great time bouncing up and down, but it is unclear how it helps with the learning process. The occupational therapist interviewed claimed that it helps with fidgeting. I try to imagine kids becoming used to sitting on said balls in order to ?concentrate? Is there any evidence to prove that it does anything other than to create "fun"? What about the physical problems that can result from such experiments?  Who is in charge of the schools anyway? Does anyone offer any protest or do parents just go along to get along?  I hope someone can answer my questions.