The diaphragm can help stabilise the Lower back by increasing the pressure in the abdomen. As the diaphragm moves down, the pressure in the abdomen increases. Your core muscles contract to maintain this pressure and therefore stabilise the lower back. This is another reason it is important to have good all round core strength.
When working well, proper diaphragm breathing also improves ventilation and oxygenation of the blood and can also help improve your posture when the lumbar spine is supported properly.
So what happens if diaphragm is not working well or is challenged by poor aerobic fitness?
As with every aspect of your body, the Nervous System controls and coordinates how the diaphragm works. When challenged, the nervous system will always select maintenance of breathing or respiration over spinal stability during an aerobic challenge.
What does this mean?
Put simply, if you are challenged aerobically, the nervous system will always want to maintain respiration even if means putting the lower back at risk. This is an example of the fight or flight mechanism.
For example, if you are doing a repetitive bending or lifting activity, such as digging, and you start to get a bit tired and puffed, aside from the loss of good technique, your back will become vulnerable to injury because your nervous system is using the diaphragm to maintain breathing and leaving the lower back open to injury.
The moral of the story is that if you are doing a repetitive activity and are feeling tired, have a break, get your breathing under control with some diaphragmatic breathing exercises and help prevent an injury.
I hope you have enjoyed this blog series on breathing. It is amazing how poor breathing techniques can cause neck and lower back problems. It can also affect your posture! Try the breathing exercise that I described in my previous post for a few weeks and see how good you will feel. Your body will thank you for it. Of course, if you have any questions, please feel free to contact me.
References
C. Liebenson, Rehabilitation of the spine, A practitioners Manual, 2nd edition, 2007
B. Hodges PW, Heijnen I, Gandevia SC. Postural activity of the diaphragm is reduced in humans when respiratory demands increases. J Physiol 2001;537(3):999-1008