The stability ball was developed in 1963 by an Italian plastics manufacturer named Aquilino Cosani. It was first referred to as a "Pezzi ball" and later, a "Swiss ball." These early stability balls were first used in physical therapy. They were introduced to the United States by American physical therapists who witnessed the effectiveness of the stability ball on physical therapy patients in Switzerland.
The stability ball helps to work core stabilizer muscles by providing an unstable surface against which the user must work. Over time, these muscles become stronger as the user exercises with the stability ball.
The primary muscles that are exercised when using the stability ball are the abdominal and back muscles. Perform stability ball exercises in seated, lying-on-your-back or lying-on-your-front positions.
Some obstetricians recommend use of a stability ball as a seat for pregnant women. The idea is that the curved surface provides relief to the lumbar spine, while toning the back and abdominal muscles that will later be used during birth.
Some office workers choose to use a stability ball rather than an office chair. The use of a stability ball in this way has been encouraged by some physical therapists. However, others discourage such use, because most stability balls are not designed ergonomically for office work.