Have you ever watched a sleeping baby breathe? Or a dog soaking in the sun breathe? Notice that their bellies, rather than their chests, rises when they inhale and becomes flat when they exhale. This is called diaphragmatic breathing (or also called ‘belly breathing’). The diaphragm is a dome-shaped muscle at the base of the lungs, between the chest and the abdomen. When you inhale (breathe in), the diaphragm contracts and moves downwards, stretching your lungs elastically to expand and fill your chest; that creates a vacuum and air flows in. When you exhale (breathe out), the diaphragm relaxes and moves upwards, allowing the lungs to elastically recoil to their deflated position; this squeezes out the air out of your lungs.
Under the everyday life stressors (i.e., tight clothing, sedentary lifestyle, talking a lot, stress, inefficient ergonomics, etc.) many of us unintentionally stop using this innate ability to correctly engage the diaphragm while breathing and we shift to a shallower type of breathing (‘chest breathing’). Chest breathing depends more on the accessory muscles of breathing like the intercostals (the muscles lining the ribcage).
Breathing is an automatic process, controlled by the autonomic nervous system (or ANS). The ANS is a division of the nervous system that unconsciously regulates many of the automatic bodily functions that we depend on every second such as our heart rate, digestion or blood circulation to different organs.
In a recent literature review, it was found that there is evidence to suggest that concussion does impact the function of the autonomic nervous system (Pertab et al., 2018). The nature of the symptoms from autonomic dysfunction confound with those of post-concussion syndrome.
Proper breathing contributes to maintaining the acid-base homeostasis of the blood. Overbreathing (or ‘over-ventilating’) is a common type of breathing dysregulation that happens when people breathe out too much carbon dioxide (CO2). Many people think about the importance of having enough oxygen (O2), and that CO2 is “just waste”. However, we need enough CO2 to maintain proper acid-base chemistry in the blood so our cells and enzymes can work optimally. Breathing out too much CO2 disrupts that homeostasis resulting in physiological, emotional and/or cognitive symptoms like:
- shortness of breath
- heart palpitations
- elevated heart rate
- numbness and tingling in the hands or feet
- feelings of unreality
- muscle tension
- difficulty concentrating
- “foggy” mind
- diaphoresis (sweating) and shivering
- blurred vision
- dry mouth
In moderate overbreathers there is a 30-40% reduction of O2 to the brain and in severe overbreathers this amount can go up to a 60% reduction of O2 to the brain (Khazan, 2013). If overbreathing persists chronically it can lead to or worsen chronic fatigue, asthma, COPD, functional abdominal pain, fibromyalgia, hypertension, chronic muscle pain and lower back pain, depression, PTSD, anxiety disorders, psychological stress/irritability, insomnia, migraines, tension-type headaches, TMJ pain and autonomic dysfunction to name a few. (Khazan, 2013).
While one can still over-breathe with any breathing style, it is more commonly present in those that practice quicker, shallower breathing – more typical of chest breathing. Using mindfulness techniques, patients can often intuitively feel the diaphragmatic breathing form that feels natural for them; the use of biofeedback expedites the learning curve.
Some patients need feedback regarding how much CO2 they are blowing off so that they can adjust their breathing to restore more physiologically-sound blood chemistry; fortunately, most will not need to use this expensive equipment.
Other than the benefits listed above about regulating CO2 levels to promote ideal blood pH and ionic potentials, diaphragmatic breathing improves O2 perfusion to the organs which in turns can also help with performance and athleticism (Hunt et. al., 2018).
Regulating CO2 levels can help alleviate some concussion symptoms. Training diaphragmatic breathing also decreases musculoskeletal tension, particularly around the neck, as it requires less effort and energy to breathe, and through efficient core recruitment, can improve balance.
There is evidence suggesting it may even help patients suffering from asthma (Venkatesan et al., 2012).
At the Toronto Concussion Clinic, one area where we start rehabilitation is by teaching our patients diaphragmatic breathing. We call it low-and-slow diaphragmatic breathing (LSDB) so as to avoid giving the impression that there is striving or effort involved; it is an easy, natural way of breathing. If we are not diaphragmatically breathing now, rest assure, we once did. As patients reconnect with this natural form of breathing, they start noticing how much easier it is, and they wonder why and how they ever got out of habit of doing it. We then train these patients in HRV training. In fact, as people recover and reintegrate into the activities of their pre-concussion lives, they comment that one of the most helpful skills they learned is HRV training.
- First, find a comfortable, quiet space to lie down.
- Can you recognize if there is any tension in your shoulders, neck, chest or core? Consciously minimize that tension.
- Place one hand on your upper chest and one hand on your abdomen (belly) to identify where the motion is coming from. And breathe in.
- Allow the motion to shift to your abdomen while minimizing the motion that takes place from the chest. The hand on your chest should remain still while the one on your abdomen should rise.
- If helpful, you can use visualization strategies like imagining a balloon expanding, or imagining air flowing past your lungs and into your belly to guide your breath.
- Ashina H, Iljazi A, Al-Khazali HM, et al. Persistent post-traumatic headache attributed to mild traumatic brain injury: Deep phenotyping and treatment patterns. Cephalalgia. 2020;0(0):1-11. doi:10.1177/0333102420909865
- Conder, R. L., & Conder, A. A. (2014). Heart rate variability interventions for concussion and rehabilitation. Frontiers in Psychology, 5, 890. http://doi.org/10.3389/fpsyg.2014.00890.
- Esterov D, Greenwald BD. Autonomic dysfunction after mild traumatic brain injury. Brain Sci. 2017;7(8):1-8. doi:10.3390/brainsci7080100.
- Hunt, Melissa & Rushton, James & Shenberger, Elyse & Murayama, Sarah. (2018). Positive Effects of Diaphragmatic Breathing on Physiological Stress Reactivity in Varsity Athletes. Journal of Clinical Sport Psychology. 12. 1-12. 10.1123/jcsp.2016-0041.
- Khazan, I. Z. (2013). The clinical handbook of biofeedback: A step-by-step guide for training and practice with mindfulness. Chichester, UK: Wiley-Blackwell.
- Kim, S., Zemon, V., Cavallo, M. M., Rath, J. F., McCraty, R., & Foley, F. W. (2013). Heart rate variability biofeedback, executive functioning and chronic brain injury. Brain Injury, 27(2), 209-222. doi:10.3109/02699052.2012.729292
- Lagos, L., Thompson, J., & Vaschillo, E. (2013). A preliminary study: Heart rate variability biofeedback for treatment of postconcussion syndrome. Biofeedback, 41(3), 136-143. https://doi.org/10.5298/1081-5937-41.3.02.
- Pertab, J. L., Merkley, T. L., Cramond, A. J., Cramond, K., Paxton, H., & Wu, T. (2018). Concussion and the autonomic nervous system: An introduction to the field and the results of a systematic review. Neurorehabilitation, 42(4), 397–427. http://doi.org/10.3233/NRE-172298.
- Thompson J., Hagedorn D. (2012). Multimodal analysis: new approaches to the concussion conundrum. Journal of Clinical Sport Psychology, 6, 22–46. doi:10.1123/jcsp.6.1.22.
- Thompson, Michael; Thompson, Lynda. Functional Neuroanatomy. The Association for Applied Psychophysiology and Biofeedback 2015.
- Venkatesan, Prem & Sahoo, Ramesh & Adhikari, Prabha. (2012). Effect of diaphragmatic breathing exercise on quality of life in subjects with asthma: A systematic review. Physiotherapy theory and practice. 29. 10.3109/09593985.2012.731626.