Is there a day that goes by when a chiropractor doesn’t deal with a postural concern? If we were to sit purely on the orthopedic wagon, we would have enough to concern us. Poor posture can cause pain- headaches, pain in the shoulders and neck, problems with the gait, uneven distribution of weight resulting in referred pain (i.e. heavy backpacks slung across one shoulder for extended periods of time).
These issues are no big surprises. But beyond the banner headlines, there is a deeper story to be told when it comes to posture and the body. Science is now revealing how posture can affect more than just pain and aesthetics. From cardiopulmonary function to digestion, pelvic floor function, and even neurodegenerative diseases, the links are becoming increasingly clear.
Posture and Cardiopulmonary Function
The first cab off the rank in this series is the important issue of posture and cardiopulmonary function. In recent times, heart rate variability has become somewhat of a rising topic in chiropractic. Whether this improvement in HRV is due to postural correction, removal of subluxation or an improvement in the patient’s state of ease (versus stress) is a matter for further investigation. What we do know, is that it’s but one potential impact of chiropractic care on the cardiopulmonary system. The power of good posture is indeed a potent thing.
In a recent series on stress (published on the Australian Spinal Research Foundation website), we explore how stress impacts posture. Once the amygdala has detected a stressor, one of the primal reactions is to drop the head forward and round the shoulders so we are ready to fight or run. But posture can also be a stressor, as rounded shoulders and forward head posture can tell the brain there is something wrong. Research also shows us there is a clear link between the two.
Among the results of the stress response are elevated heart rate and increased blood pressure – neither of which is ideal if stress becomes chronic and the stress response settles in for the long haul.
But in the smartphone era, we are living in a world that seems to burst at the seams with cases of cervical or thoracic kyphosis. What does this do to the cardiopulmonary function apart from impacting the stress response (including heart rate variability and blood pressure, the latter being an issue there’s a lot of chiropractic research on)?
Rene Caillet MD, author, and director of physical medicine and rehabilitation at USC, says “lung capacity can be reduced by as much as 30% in individuals with thoracic kyphosis. ”
This thoracic kyphosis is “very closely linked with several other postural imbalances that play off each other including: forward head posture, cervical flexion, rounded shoulders, scapular abduction and winging, internal humeral rotation and depressed ribs” . The latter are facts easily gleaned from basic science. Still, research is increasingly linking the thoracic kyphosis with the forward head posture and rounded shoulders. 
In fact, Singla et al found that “Cervical Lordosis values were found to be significantly associated with thoracic kyphosis values. Also, there were significant correlations between rounded shoulders and increased thoracic kyphosis .
They went on to link these presentations with:
- Computer use
- Carriage of backpacks
- Use of Smartphones
- Mouth breathing
- Shoulder overuse
A growing number of research papers are indicating that cervical kyphosis can have a negative impact on tidal volumes [4,5].
In both Landers et al and Bidhay et al, patients exhibited improvements in pulonary function when they were moved from sitting to supine positions – the latter position effectively relieving the cervical kyphosis.
In the case of Landers, it was stroke patients under the proverbial microscope, and these also benefited from thoracic mobilisation . In the case of Bishay, it was a wheelchair-bound 22-year old with notable cervical kyphosis and low tidal volume. 
But what does lowered tidal volume and lung capacity mean? We don’t really need to view new research asserting that we need oxygen to stay alive, but just how much of difference oxygenation makes to blood and the various tissues in the body, and then performance and concentration is another topic altogether – once scientists interested in peak human performance still investigate.
On the illness end of the spectrum, lowered lung capacity or tidal volume can play into conditions like asthma, emphysema, chronic obstructive pulmonary disease, pulmonary oedema, and bronchitis among many others.
On the wellness end of the spectrum, we need good oxygenation to enjoy a broad range of activities, whether athletic, leisurely, or academic. (Who has ever tried to write a brilliant piece of academic work while feeling dizzy or foggy-headed?)
Can we (chiropractors) claim to cure any of these problems? The answer is, NO.
But we can remove subluxations, advise stretches and help patients reclaim up to 30% in lost lung capacity and tidal volumes.
How do we measure it?
It makes sense that if we are claiming to make a change to someone’s posture and that this impacts cardiopulmonary function, we should be able to measure it. How do we do that in clinical practice? The main tool chiropractors use maybe their hands, but there is a plethora of ways we can measure the impact on cardiopulmonary function without adding to or subtracting from our modality.
HRV (Heart Rate Variability)
As mentioned above, Heart Rate Variability (HRV) is becoming increasingly visible in the world of chiropractic. Heart rate proper may be used as an indicator of health in other ways, but when applied to chiropractic, HRV can give us unique insight into adaptation, as it gives us a clear look at what is happening in the cardiopulmonary system pre and post adjustment. As for how we measure it, CLA (the Chiropractic Leadership Alliance) Insight Station now measures HRV. There are also some wearable wrist devices that can achieve the same thing.
Cardiac Recovery Tests
In another recent article, Dr Micheal Hall discussed a cardiac recovery test we can use in practice to assess how fast a patient’s HRV comes back down to normal after physical activity. It involved taking their heart rate, getting them to march on the spot for two minutes, and then timing to see how fast their heart rate come back down. For adults, a normal resting heart rate should be between 60 and 100 beats per minute, and the lower it is, the healthier person is thought to be . Dr Hall cautioned that anything over 80 should make us raise an eyebrow.
By using the simple assessment of resting heart rate followed by a simple, non-invasive cardiac recovery test, we can get some insight into a patient’s level of stress and cardiopulmonary function.
Pulse Oximetry is another simple way of measuring cardiopulmonary function. In a 2012 edition of Jurnal of Chiropractic Medicine, Hall and Jensen put forward a rationale for its use in chiropractic care, suggesting that it has the potential to be an integral part of chiropractic practice :
“Pulse oximetry simply gives us an indication of a patient’s oxygen saturation levels. It is seen commonly in hospitals and is as simple as placing a clip on a patient’s finger in order to glean potentially lifesaving information. Halland Jensen offered three reasons for the inclusion of pulse oximetry into chiropractic practice:
- Pulse oximetry allows for quick and reliable retrieval of oxygen saturation and heart rate values previously not readily obtained or used.
- Pulse oximetry allows for immediate assessment of potentially hypoxic patients.
- Pulse oximetry allows for important changes in patients management potentially influencing outcomes and safety.
Dr David Fletcher, of CLA, has advised that pulse oximetry is something on the horizon for new editions of the Insight Stations, so this technology will soon become easier for chiropractors to get hands-on.
This technology is a simple way to measure tidal volumes. It simply measures how much air you can inhale and exhale quickly, giving insight into the movement of the lungs. Spirometers vary in price from a few hundred to a few thousand dollars. It’s fast, easy, and gives a tangible way to demonstrate an added benefit of chiropractic care.
Measuring chest expansion
Spirometers are cheap but if, you’d rather avoid the use of another device, measuring chest expansion is an option. (As an added benefit, it costs you even less and can work as a great outcome measure).
We can see from basic science that posture has a significant impact on cardiopulmonary function. We also know that chiropractors are uniquely positioned to assist patients with postural concerns. What data should show us, now more than ever as instances of cervical/thoracic kyphosis are on the rise, is how important this could be.
- “Effect of thoracic and cervical joint mobilization on pulmonary function in stroke patients”, Sang-Hun Jang, PT, PhD1 and Hyun-Soo Bang, PT, PhD1, Stress Series part 3
- Whitehead M (2015), “How Posture Affects Lung Capacity”,
- Association Between Forward Head, Rounded Shoulders, and Increased Thoracic Kyphosis: A Review of the Literature, Deepika Singla, MPT Sports, BPT⁎ and Zubia Veqar, PhD, MPT Ortho, BPT, Journal of Chiropractic Medicine 2017, pp. 22-229
- Landers, M, Barker, G, Wallentine, S, Wesley-McWhorter, J and Peel, C (2003),“A Comparison of Tidal Volume, Breathing Frequency, and Minute Ventilation Between Two Sitting Postures in Healthy Adults,” Physiotherapy Theory and Practice
- “A Cervical Case? Improvement in Pulmonary Function Flows from Sitting to Supine“, Lara C. Bishay , Charles Berde , Dennis Rosen, retrieved, 24 September 2018
- GONCALVES “Comparison of thoracic kyphosis between a patient with chronic obstructive pulmonary disease and a healthy individual by the flexicurve method”, Marcia Aparecida GonçalvesPatrícia Leite RodovalhoAngela Jacques BelliniAna Karla Vieira BruggemannGiovana Zarpellon MazoElaine Paulin
- Staff Writer 2018, “Improvements in HRV under chiropractic care “, Australian Spinal Research Foundation
- Staff writer 2018, “Resting Heart Rate”, Health Direct, retrieved 26 September 2018
- “The role of pulse oximetry in chiropractic practice: a rationale for its use”, Michael W Hall 1, Anne M Jensen, (2012), Journal of Chiropractic Medicine, pp.127-133
- Staff Writer (2018), “Spirometry”, Lung Foundation Australia