At Heatherstone Elementary School in Olathe, Kansas, according to a story in The Kansas City Star in April, children sit on large blue or yellow exercise balls instead of chairs. Fidgety kids direct excess energy into staying balanced, the Kansas teacher told the newspaper, “allowing them to focus on learning.” They sit up straight, and their improved posture sends more blood to the brain, also a learning boon, she added.

Colorado teacher Lisa Witt studied a dozen of her sixth-grade students in 2001 to demonstrate the benefits of the balls to a skeptical principal. Video studies of the students showed improved posture, more time spent on task and less squirming while they sat on the balls, she told the newspaper. “People are not meant to sit still.”

Ellner’s biggest argument for the balls is fit. “We have all different sizes of children, but the desks and chairs are all the same.”

Cheryl Bennett, ergonomics specialist at Lawrence Livermore National Laboratory in California and chair of the Ergonomics for Children and Educational Environments committee of the International Ergonomics Association, agrees that kids need furniture that fits. The balls come in different sizes and can be inflated for a customized fit, which is a big advantage, Bennett told The Star. Studies have found mismatches of up to 90 percent between classroom furniture and the children who use it, she said. “That means furniture is fitting only 10 percent of kids.”

In the April 2005 edition of Ergonomics Today™ and the Ergonomics Forum from the same period, several expert contributors found fault with the balls as adult workplace seating. An interviewee in the first publication said it was audacious to describe the balls as “ergonomic” and a means of preventing back pain. A Forum contributor worried about the “huge compression placed on the intervertebral discs.” One described spinal risks, and pointed to the high potential for injury because users can become unbalanced and fall off the ball. Another said he advised against use of the balls because, unlike chairs, they are not designed to be a sitting surface.

The classroom examples show benefits for children, while the comment in the two ergonomics publications focus on the potential for harm in the adult workplace. The question is children using the balls are as vulnerable as adults, and whether benefits for them outweigh the potential for musculoskeletal disorders and injuries.

Sources: Kansas City Star; Ergonomics Today™; Ergonomics Forum