The Diaphragm

The Diaphragm

The diaphragm, sometimes called the thoracic diaphragm due to its positioning, is a thin sheet of strong muscle that sits underneath the ribs. It is a dome-shape that separates the abdominal cavity from the thoracic cavity (heart, lungs & ribs). The diaphragm plays a very important role in respiration.

During inhalation, the diaphragm contracts down and spreads out, increasing the spatial capacity of the thoracic cavity by increasing the vertical dimensions of the chest cavity. This contraction reduces ‘intra-thoracic pressure’ i.e. the enlargement of the cavity draws air into the lungs by creating suction. This helps to ensure that our optimum lung capacity is utilized.

When our diaphragm relaxes, the lung creates an elastic recoil which causes air to be exhaled out of the lung as well as from the various tissues that line the thoracic cavity. When working with the abdominal and intercostal muscles, this reaction becomes an antagonist for the contraction of the diaphragm.

The diaphragm is actually involved in other functions of the body. It helps to expel faeces and urine as well as vomit from the body. It does this by increasing the ‘intra-abdominal’ pressure. Another function it helps in the body is that it helps to prevent acid reflux by exerting pressure on the oesophagus as the acid travels past the oesophageal hiatus.

            The diaphragm is covered by the lower area of the parietal pleura. When the diaphragm contracts the pleura is pulled down creating a lower pressure that lowers the alveoli, so drawing air into the lungs. When the individual breathes out, the diaphragm is made to relax and it goes back to its normal, balanced position. This entire process is repeated at a more rapid rate when an individual exercises. This is due to the fact that, in quiet breathing the diaphragm moves only a couple of centimetres whilst doing exercise, the diaphragm can move up to ten centimetres.

For performers, the diaphragm is an incredibly vital organ and it is important for us to understand and know when our diaphragm is being engaged properly. We need to ensure, that when engaging the diaphragm in the correct manner when inhaling, our bellies should be pushed out, this is because of the diaphragm is contracting down and filling our abdominal cavity as well as the abdominal muscles will be working in an antagonistic manner with the diaphragm.

The diaphragm is an essential element in projection and breath control, and to develop a full control of our diaphragm is vital so that we can control our breathing during performances such as performing a monologue or singing a song. Having a control on our breathing is vital as bad control can actually lead to damaging your vocal cords. Often when singing, or performing on stage, using our voice with an incorrect breathing technique will often lead to over-use or straining of the voice. The problems that can be caused from straining include:

-         Scratchy breaks in your voice

-         Inability to reach high notes (singing)

-         A weak and powerless vocal sound (this will cause problems with projection)

-         Pitch problems (singing)

-         A shortness of breath while singing

-         Formation of vocal nodules (can permanently impair your vocal cords)