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
Ball detent folding knives to prevent unwanted opening of the blade when carrying it. The term "ball detent" is also used when referring to a mechanism in paintball markers designed to prevent the paintball from rolling out of the firing chamber before being fired. Some designs are similar to those outlined above, with a cartridge utilizing a ball bearing in a bore with spring pressure. The cartridge is installed perpendicular to the barrel bore axis, just ahead of where the ball rests before being fired. Other designs use elastic rubber protrusions that block the ball until it is pushed over it by