If you listen to all the hype, we’ll all be sitting on large rubber balls some day instead of traditional chairs. Inflatable ball chairs resemble the popular exercise devices found in numerous gyms and health clubs.

Many grammar schools around the United States are already using ball chairs in the classroom. The devices force students to frequently change positions to maintain balance. That leads to increased alertness and concentration. According to experts, when kids shift position on the chairs, they use their core muscles, which helps stimulate their brains, resulting in better focus.

Ball chairs can be modified with wheels, arm rests and back supports for office or assembly line applications. However, the devices have pros and cons.

“There are [advantages] to using exercise balls,” claims Julia Abate, senior ergonomist at the Ergonomics Center of North Carolina, which is housed in the Edward P. Fitts Department of Industrial and Systems Engineering at North Carolina State University. “It’s cheaper than purchasing a good chair; it works the core muscles (some call this ‘active sitting’); and it does not place direct pressure on the legs, as some chairs do.

“However, some versions are also very unstable and adjust in height, usually by inflation or deflation,” adds Abate. “The balls also lack true lumbar support, and most users I’ve seen will sit in a slouched position after a period of time, especially as their muscles get tired from the workout provided when sitting straight.

“As for use in assembly, I would personally not recommend it,” warns Abate. “Largely, it’s a matter of safety and stability. For example, if the operator has to reach for any parts or products during the assembly process, their center of gravity on the ball would shift, and could result in a fall or injury.”

Recent research indicates that sitting on an exercise ball might positively affect static and dynamic aspects of working posture. But, old-time balance balls that are commonly used in Pilates classes are “not meant to be used in a working environment for 8 hours a day,” says Cynthia Roth, CEO of Ergonomic Technologies Corp. “Ball chairs can be unsafe, because they put all of the stress on abdominal and back muscles.

“I see this as just another gimmick,” notes Roth. “It’s similar to the kneeling chair, which was a popular fad back in the early desktop computer days. Today, few people use the devices because they can harm your knees.”