The benefits of correct diaphragmatic breathing have been extolled by yoga and meditation teachers for years, but a recent study has highlighted how much your breathing affects your brain and emotions:
So what exactly is the diaphragm? Well, this is a large thin sheet of muscle which divides your heart and lungs from the abdominal contents (your stomach, liver, gut and other organs). It is dome shaped at rest, but when you take a deep breath the muscle flattens and descends, pulling air into the lungs. Below you will see just how far up into the ribcage it extends at rest.
Try this simple breathing exercise: lying on your back, place your hands on your abdomen. As you take a deep breath in, your hands should naturally rise up, as the diaphragm flattens, pushing the abdominal contents downwards and outwards. (If you watch babies and small children, they breathe like this naturally- but adults sometimes have to re-learn this skill!)
In practice, I often find a tight diaphragm is part of the problem in patients with low back pain. As you can see, it attaches onto the lumbar spine (labelled left and right crus in this image) and is closely associated with two other prime suspects- the psoas major and the quadratus lumborum. So do your back a favour and practice some diaphragmatic breathing today!