It increases the anteroposterior diameter by elevating the upper ribs with the help of the sternum; its significance in the physiology of respiration is obvious. Remember this when “assessing breathing patterns”… structure dictates function and the diaphragm has links to many structures including the spine, the lungs, rib cage and ABS. Stress can affect the diaphragm via the ANS and aerobic training, and sport can also affect the diaphragm, making it tighter, as it is a muscle. Tensegrity Biomechanics and Complexity explains all of this.