The knowledge of how to breath with your diaphragm comes pre-programmed in every new baby. It is well understood and implemented by the infant with no complications.
How does breathing get messed up and lead to neck problems?
The diaphragm is your primary breathing muscle. It is a thin, wide sheet of muscle that separates the rib cage from the abdomen. It has a high domed shape which flattens out significantly when it contracts. The dome-shape is much more pronounced than most people realise, and that shape is important to understand.
When the diaphragm contracts, that dome flattens significantly to allow space for the lungs to expand. As it flattens it pushes downwards on the viscera in your stomach. As the viscera is like liquid, which can not be compressed, the stomach must bulge out to accommodate the action of the diaphragm. Hence, good breathing is usually described as “abdominal breathing” or “diaphragmatic breathing.” So the stomach in a person breathing correctly looks a bit like the happy buddha when they are breathing in.
The innocent infant grows into a self conscious teen and adult who responds to cues around them to keep their tummy in, in response to vanity. Smaller, less efficient muscles in the upper chest, throat and neck designed to help breathing in times of high demand (like running) are recruited to do the every second of every day task that is breathing. These are called accessory muscles e.g.. pectorals minor and scalenes. These are small muscles which quickly become overused and tight, leading to poor muscle stability around the shoulder and neck. See the connection to neck pain !
How to practice breathing your diaphragm
1. Lie on your back – put one hand on your chest and one hand on your tummy. As you breath in, allow your tummy to rise (do not push it up) while your chest does not move. To breath out, allow your tummy to flatten. Practice this in different positions. Sitting is the hardest. Practice this during different tasks and activities such as walking, gym, hanging out the washing etc.
2. To strengthen/condition your Diaphragm you can put a large heavy book on your stomach while lying on your back and practice diaphragm breathing with the extra weight of the book on your stomach. You could start by doing 20 breathes once a day and build up to more if you feel comfortable.