Christmas article: Impact of handstand on airway resistance and pulmonary diffusing capacity in healthy humans

Abstract

Introduction: Postural changes are known to have a significant influence on lung function and gas exchange due to the gravitational influence on the lungs, as postural changes alter the lungs' orientation relative to gravity. Previously, assessing lung function in more challenging postures was difficult due to limitations of available equipment. However, with the development of handheld equipment, it is now possible to investigate lung function in different postures. Therefore, this study aimed to investigate the effects of postural changes, including supine and quadruped postures, as well as handstands, on airway resistance and pulmonary diffusing capacity.

Methods: Twelve healthy young participants underwent measurements of impulse oscillometry and pulmonary diffusing capacity with carbon monoxide corrected for haemoglobin (DL,COc) during upright standing, as well as in the supine, quadruped, and handstand postures.

Results: Total airway resistance increased from upright standing to supine (p less-than 0.001) and handstand (p less-than 0.001), and small airway resistance increased from upright standing to handstand (p = 0.019). DL,COc increased from upright standing to supine (p less-than 0.001), quadruped (p = 0.028) and handstand (p less-than 0.001), whereas DL,COc were lower in quadruped posture compared to supine (p = 0.007) and handstand (p = 0.022), with no difference between supine and handstand (p = 0.17).

Conclusion: Both supine posture and handstand increase airway resistance compared to upright standing, whereas supine and quadruped postures, as well as handstand, increase pulmonary diffusing capacity similarly.

Funding: The Centre for Physical Activity Research (CFAS) is supported by TrygFonden (grants ID 101390, ID 20045, ID 125132, and ID 177225).

Trial registration: None.