To review, a normal breath in, causes the ribs to move up and out, the diaphragm moves down. The diaphragm returns to a dome, the external intercostal muscles rest, the ribs drop back down to a resting state. Normal expiration is a relaxed process.A piston like motion occurs as the central tendon of the diaphragm pulls the diaphragm down into the abdomen. The side of the rib cage opens up the thoracic cavity in a bucket handle motion, and the lower ribs open in a caliper motion and all mechanics help to increase the thoracic cavity volume. The front to back portion of the rib cage increases in diameter through this mechanism. The thoracic spine or back extends or straightens as we inhale, which allows the breast bone to expand further forward. As we inhale, normally the chest wall will move forward and upward at the breast bone and upper ribs in a pump handle motion.At the front of the body, ribs 1-7 articulate with the sternum or breastbone, and then ribs 8-10 connect by way of cartilage to the ribs above, whereas the ribs 11-12 are floating at the front of the body. At the back of the body, the rib cage articulates with the 12 thoracic vertebrae (back bones). The rib cage also helps to protect our internal organs. The rib cage provides the site for the muscles to attach which allows the thoracic cage to expand larger during the inhale, or compress the thorax during exhale.As we exhale, air leaves the lungs and carries carbon dioxide out of the lungs. As we breathe out, the external intercostals relax which causes the chest wall to relax, and the diaphragm relaxes which allows it to return to it’s domed shape.The external intercostal muscles and diaphragm contribute to an increase in the volume (opening) of the thoracic cavity which allows the lungs to bring air and oxygen inward. Simultaneously, the external intercostal muscles (muscles between the ribs) contribute to inhalation (breath in) by lifting the ribs up and out, also allowing air to travel into the lungs. The diaphragm travels down into the abdomen as we take a breath in or inhale, allowing air to travel inward into the lungs. Our diaphragm is a large domed shaped muscle.For example, in normal breathing biomechanics, we can explore the diaphragm muscle, the intercostal muscles, the joints of our rib cage/thorax, and accessory or helper muscles. This understanding can help set breathing goals. Why understand normal breathing? If we understand normal, then we can understand when something is different with our breathing. A tune up of the respiratory system in general, can go a long way especially with our current COVID-19 crisis. Did you know that you can strengthen your breathing muscles and breathing mechanics? Just like lifting weights to build muscle, or stretching to improve flexibility, you can complete breathing exercises to help strengthen and lengthen your diaphragm, intercostals (muscles between the ribs) and rib cage. With the current COVID-19 pandemic, revisiting our natural biomechanics of breathing could not be more appropriate. Our breathing mechanism is driven by muscles and joint mobility. On a day to day basis, an adult takes 12-18 breaths per minute. You acknowledge that you should consult with a physician prior to starting any exercise program and should follow any restrictions placed on your activity by your physician or other healthcare providers. You should not perform these exercises unless you are in good health and not currently under medical care for any condition that would potentially prevent you from exercising. The Forgotten Biomechanics of Breathing: a reminder of our internal breathing mechanism during the time of COVID-19īy accessing and reading this blog’s reference to exercises, you acknowledge and agree that these exercises and blog posts are intended as examples for general fitness and educational purposes and are not intended for the treatment of a medical problem or disorder.

Muscles of inspiration