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
Nessler ball Nessler ball The Nessler ball, or balle Nessler, is a type of muzzle-loading musket bullet. It was developed to increase the accuracy and range of smoothbore muskets and was used in the Crimean War. The Nessler ball was a short conical-cylindrical soft lead bullet, with a conical hollow in its base. The bullet was designed with a lead skirting. Its intended purpose was to expand under the pressure and obturate the barrel and increase muzzle velocity. A similar ball design called the Chace ball (after its inventor W.B. Chace) was developed in 1861 in the United States but was not