Exercise balls are used for both physical therapy and exercise to help with conditioning and strength. Since you use more muscles to keep you balanced while doing exercises normally performed sitting, lying or standing, exercise balls provide a fuller conditioning effect. When used with physical therapy rehab exercises, these balls can promote flexibility, coordination, motor skills, strengthening, and balance.They can also be used in sports medicine, Pilates, aerobics, yoga and as a birthing ball. They are perfect for stretching, improving posture and performing balance exercises. Also known as stability balls, gym balls, gymnastic balls, Swiss balls, body balls, therapy balls, fitness balls, balance balls or yoga balls.