Vital Areas

Subaxillary Region

Fourth intercostal space. May cause loss of consciousness due to trauma to lungs and associated nerves, leading to loss of lung function and stoppage of breathing and circulatory failure.

Area below Nipples

Between the fifth  and sixth ribs on either side. May cause loss of consciousness due to similar to loss of lung function, stoppage of breath, and circulatory failure.

Commotio Cordis

Also known as cardiac concussion. This is a syndrome in which a non penetrating impact to the chest causes heart failure but causes little or no structural damage to the body or the heart. A common victim is a player who takes a baseball, hockey puck, or other hard object in the chest, but it also could be a punch or kick. About half the time, the victim collapses immediately; otherwise, it usually occurs within a minute or two. Death is thought to result from ventricular fibrillation, a state in which the lower heart chambers start fluttering and stop pumping blood. One study of 128 cases reported that 84 percent of the victims died, with nearly all the survivors receiving prompt defibrillation. Relatively little force is required for the killing blow; one researcher estimates that the blunt instrument need be moving at only 30 mph. Although this is a proven medical phenomenon, animal experiments indicate that one must strike within a 15-20 millisecond window in the heartbeat cycle to have a reasonably good chance of taking down an attacker; therefore, in a self-defense situation, it is practically useless.