This "squishiness," George describes, "enables the person to wedge it powering their back for Main work or squeeze at the rear of their knee for glute exercises. Should the ball is just too stiff, it may be difficult to hold onto or place your body in uncomfortable angles and positions." https://advertisesmart.com/view/post/The-Ultimate-List-of-Facial-Exercises-for-Glowing-Skin/112