Prescribe Posture Correction to Improve Respiratory Function

 In ideal posture, the ears align vertically with the shoulders, and the back is relatively flat. Forward-head posture refers to a common postural misalignment where the head translates anteriorly. Thoracic kyphosis (shoulders rounded forward) often accompanies forward-head posture. Research connects forward-head posture to a number of maladies more commonly considered in the exercise-therapy domain: neck pain & disability,2-4 tension headache,5 reduced function of the upper limbs,6,7 and shoulder dysfunction.8 However, treatment plans for respiratory difficulties also include posture correction, because the connection between forward-head posture and reduced pulmonary capacity is well established for both young and old patients. Various studies show the correlation between forward-head posture and impairment in these measures of pulmonary function: peak expiratory flow, maximum voluntary ventilation, forced vital capacity, forced expiratory volume in the 1st second, expiratory reserve volume, and inspiratory reserve volume.9-13 The mechanism by which forward-head posture causes respiratory deficiencies has been less clear, as some studies have connected chronic neck pain with respiratory dysfunction.14-18 In as much as forward-head posture is associated with neck pain, this invites questions such as, “Which is causal, posture or pain?” or “Do both posture and pain contribute to respiratory dysfunction?”

Some have theorised that disturbed neuromuscular control associated with chronic pain maybe a mechanism of action.19 This hypothesis suggests a possible analgesic approach to improving respiratory function. Entering the fray, we have Ahmad Mahdi Ahmad and colleagues from Cairo University’s Department of Physical Therapy for Cardiovascular and Respiratory Disorders and Department of Chest Diseases. Their first-of-its-kind study recruited people with chronic neck pain. Subjects reported an average neck-pain duration of two or more years. Researchers divided their subjects between people with forward head posture (craniovertebral angle > 50 degrees) and people with normal head posture. Then, they used ultrasound to measure diaphragmatic excursion (movement of the thoracic diaphragm) during deep inspiration. Greater excursion indicates greater respiratory capacity. Normal, right-side diaphragmatic excursion during deep inspiration reaches 66 mm.20 On average, Ahmad et al.’s chronic-neck pain patients with normal head posture achieved the standard diaphragmatic excursion, 67.6 mm.

On the other hand, patients with forward-head posture averaged a diaphragmatic excursion that was 16% lower, 57.0 mm. The study results suggest that neck pain may not be causal for respiratory dysfunction, and that neck pain is associated with respiratory dysfunction because forward-head posture causes both. Forward-head posture biomechanically causes constriction of the lower thorax, reduced movement of the lower ribs, and abdominal muscle shortening.13, 21,22 This is believed to be the cause of the strong association between forward-head posture and respiratory muscle weakness.23

References

1. Ahmad A, Kamel KM, Mohammed RG. Effect of forward head posture on diaphragmatic excursion in subjects with non-specific chronic neck pain. A case-control study. Physiotherapy Quarterly. 2022;28(3):9-13.

2. Yip CH, Chiu TT, Poon AT. The relationship between head posture and severity and disability of patients with neck pain. Manual Therapy. 2008 Apr 1;13(2):148-54.

3. Kim DH, Kim CJ, Son SM. Neck pain in adults with forward head posture: effects of craniovertebral angle and cervical range of motion. Osong Public Health and Research Perspectives. 2018 Dec;9(6):309.

4. Ha SM, Kwon OY, Yi CH, Jeon HS, Lee WH. Effects of passive correction of scapular position on pain, proprioception, and range of motion in neck-pain patients with bilateral scapular downward-rotation syndrome. Manual Therapy. 2011 Dec 1;16(6):585-9.

5. Fernández‐de‐las‐Peñas C, Alonso‐Blanco C, Cuadrado ML, Gerwin RD, Pareja JA. Trigger points in the suboccipital muscles and forward head posture in tension‐type headache. Headache: The Journal of Head and Face Pain. 2006 Mar;46(3):454-60.

6. Kwon JW, Son SM, Lee NK. Changes in upper-extremity muscle activities due to head position in subjects with a forward head posture and rounded shoulders. Journal of Physical Therapy Science. 2015;27(6):1739-42.

7. Weon JH, Oh JS, Cynn HS, Kim YW, Kwon OY, Yi CH. Influence of forward head posture on scapular upward rotators during isometric shoulder flexion. Journal of Bodywork and Movement Therapies. 2010 Oct 1;14 (4):367-74.

8. Singla D, Veqar Z. Association between forward head, rounded shoulders, and increased thoracic kyphosis: a review of the literature. Journal of Chiropractic Medicine. 2017 Sep 1;16(3):220-9.

9. Han J, Park S, Kim Y, Choi Y, Lyu H. Effects of forward head posture on forced vital capacity and respiratory muscles activity. Journal of Physical Therapy Science. 2016;28(1):128-31.

10. Kim MS, Cha YJ, Choi JD. Correlation between forward head posture, respiratory functions, and respiratory accessory muscles in young adults. Journal of Back and Musculoskeletal Rehabilitation. 2017 Jan 1;30(4):711-5.

11. Kang JI, Jeong DK, Choi H. Correlation between pulmonary functions and respiratory muscle activity in patients with forward head posture. Journal of Physical Therapy Science. 2018;30(1):132-5.

12. Zafar H, Albarrati A, Alghadir AH, Iqbal ZA. Effect of different head-neck postures on the respiratory function in healthy males. BioMed Research International. 2018 Jul 12;2018.

13. Koseki T, Kakizaki F, Hayashi S, Nishida N, Itoh M. Effect of forward head posture on thoracic shape and respiratory function. Journal of Physical Therapy Science. 2019;31(1):63-8.

14. Dimitriadis Z, Kapreli E, Strimpakos N, Oldham J. Respiratory weakness in patients with chronic neck pain. Manual Therapy. 2013 Jun 1;18(3):248-53.

15. Dimitriadis Z, Kapreli E, Strimpakos N, Oldham J. Pulmonary function of patients with chronic neck pain: a spirometry study. Respiratory Care. 2014 Apr 1;59(4):543-9.

16. Wirth B, Amstalden M, Perk M, Boutellier U, Humphreys BK. Respiratory dysfunction in patients with chronic neck pain–Influence of thoracic spine and chest mobility. Manual Therapy. 2014 Oct 1;19(5):440-4.

17. Dimitriadis Z, Kapreli E, Strimpakos N, Oldham J. Respiratory dysfunction in patients with chronic neck pain: What is the current evidence?. Journal of Body Work and Movement Therapies. 2016 Oct 1;20(4):704-14.

18. Kahlaee AH, Ghamkhar L, Arab AM. The association between neck pain and pulmonary function: a systematic review. American Journal of Physical Medicine & Rehabilitation. 2017 Mar 1;96(3):203-10.

19. Kapreli E, Vourazanis E, Strimpakos N. Neck pain causes respiratory dysfunction. Medical Hypotheses. 2008 Jan 1;70(5):1009-13.

20. Fayssoil A, Behin A, Ogna A, Mompoint D, Amthor H, Clair B, Laforet P, Mansart A, Prigent H, Orlikowski D, Stojkovic T. Diaphragm: pathophysiology and ultrasound imaging in neuromuscular disorders. Journal of Neuromuscular Diseases. 2018 Jan 1;5(1):1-0.

21. Szczygieł E, Węglarz KA, Piotrowski K, Mazur T, Miętel S, Golec J. Biomechanical influences on head posture and the respiratory movements of the chest. Acta of Bioengineering and Biomechanics. 2015;17(2).

22. Ito Y, Yamada T, Takeda M. Investigation of respiratory function and breathing pattern in elderly people with kyphosis posture. Rigakuryoho Kagaku. 2007;22:353-8. 23. Kapreli E, Vourazanis E, Billis E, Oldham JA, Strimpakos N