The stability ball is one of the most versatile pieces of fitness equipment. It is used by physical and occupational therapists, yoga and pilates instructors, chiropractors, and other health and fitness professionals, for exercising, strengthening, rehabilitating, specific sports training, and more. It is also used as a replacement to the traditional office chair, as the simple act of sitting on the ball activates core, abdominal, and trunk muscles, strengthening and toning them throughout the day.