My view of center mass targeting is formed by the location of absolutely vital organs. These lie below and around the sternum. The location and size of the sternum The sternum is at the center of the rib cage beginning at the collar bones and extending downward. The average dimensions of the human sternum are stated below. Males have larger sternum than females, but for the purposes of this article the differences are insignificant. Length: 7 inches Thickness: 0.4 inch Breadth: tapering top to bottom - 2.75 inches to 1.25 inches The sternum is attached to the ribs by cartilage. Cartilage is significantly softer than bone. The ribs are significantly thinner than the sternum and vary in thickness and shape depending upon their placement in the rib cage. The rib cage protects vital organs. The most vital organs other than the brain are behind the rib cage, which is intended to provide protection for those organs. In the image below we see that the heart, lungs, and major artery idea and veins are all in the rib cage connected by the sternum. To the rear of the sternum is the thoracic spinal column. The main arteries and veins that carry blood to and from the heart to the brain and lungs are all encased in the sternum's rib cage area. That can be seen in the image. The relationship of accuracy to incapacitation is an accepted fact that a well placed shot that disrupts the central nervous system, or causes massive bleeding, or injures a vital organ will incapacitate or kill an attacker in quick order. While the brain is an ideal target, the area of the head is smaller than the thoracic cavity. The head can move much faster than the upper torso. That makes the upper torso a better target in self defense. While the upper torso is often thought of anything above the waist, in fact it is anything from the relative position of the lungs to the neck. Tghe body portion below that is the mid section until the hips where the lower body begins. What is center mass? The recommendation of most deaf defense trainers is to shoot for center mass, but what does that mean? For me it aim at the sternum. Below is the new target I am going to use.