Exercise ball a chair because of ergonomic considerations or biomechanical reasons. This large plastic ball, known as a "birth ball", can also be used during labour to aid the descent of the fetal head into the pelvis. Sitting in an upright position will also aid fetal positioning and is more comfortable for the woman. Sitting on the ball with arms placed on a bed, table or otherwise sturdy object for support and gently rocking the hips may help the woman during contractions and aid the natural physiological process of birth. Exercise ball An exercise ball, also known as a Swiss Ball, is
Three-ball 2 and 3 balls) are racked either in a triangle — usually aluminum, wooden or plastic, like a miniature eight-ball or snooker rack — with the apex ball on the , or in a straight line, again with the lead ball on the foot spot, and the other balls behind it, lined up toward the center of the . No particular arrangement is necessary, as there is no specific order in which the balls must be pocketed, nor do any of them have specific point values. Racking is often simply done by hand, though there have been at least two