Effects of ventilation on body sway during human standing

Lung, 1987

We measured minute ventilation (~rE), tidal volume (Vr), mean inspiratory flow (Vr/T0, and occlusion pressure (P.~) in I0 resting subjects breathing room air, in sitting, supine, right and left lateral positions, and compared them with corresponding data on static lung compliance [Cst(1)], dynamic lung compliance [Cdyn(l)], and pulmonary flow resistance JR(l)]. Highest values for Vv, VE, VT/Tb P.~, and effective inspiratory impedance [P.1/(VT/Ti)] were observed in the supine posture. Values for P~ and P.I/(VT/ T~ in lateral decubitus were intermediate to those obtained when seated and supine. While the increases in P.1 and P.j/(Va-/TI) in recumbent postures were qualitatively similar to the decrease in Cdyn(/) and increase in R(/), there was no significant correlation between them, probably reflecting the complex relationship between P.J(Vr/T~) and lung compliance and resistance, as the former, in addition to lung mechanics, also depends on the shape of the inspiratory driving pressure wave, the active inspiratory impedance, the mechanics of the chest wall, and the duration of inspiration.

National Journal of Physiology, Pharmacy and Pharmacology, 2022

Background: Pulmonary function parameters can be altered with the change in body position. Therefore, physiological basis behind such consequent influence is essential to be understood. Pulmonary function tests are generally conducted in the erect sitting posture as it is more feasible and comfortable. However, bedridden patients are unable to do so and only few studies are found on recumbent postures. Thus, to comfort such patients in breathing, need arises to meet this requisite investigation to conclude the best recumbent body posture. Aim and Objectives: To compare and assess forced vital capacity (FVC), forced expiratory volume in 1 second (FEV 1), FEV 1 /FVC ratio, forced expiratory flow of during 25-75% expiration (FEF 25-75% , and peak expiratory flow rate (PEF) in the Supine, Crook-lying and Fowler's position. Materials and Methods: The present research was carried out on 128 healthy adults to measure FVC, FEV 1 , FEV 1 /FVC ratio, FEF 25-75% and PEF using a computer-based spirometer in the Supine, Crook-lying and Fowler's position. One-way Analysis of Variance with Tukey HSD post-hoc test was utilized between each body postures by evaluation of their mean values. Results: This study consisted of 128 subjects (males 57, females 71) with mean age of 21.62 ± 1.75 years, mean weight 59.71 ± 9.97 kg, mean height 164.68 ± 9.30 cm and Body mass index 21.91 ± 2.38 kg/m 2. Fowler's posture showed significantly (P < 0.05) higher value in all spirometric parameters as compared to other two postures. Outcome of the study showed all spirometric parameters value-greater in the Fowler's posture than that of Supine or Crook-lying posture. Conclusion: The implication of this research is that it will meet the need of selection of the most suitable substitute posture for better pulmonary functioning in bedridden people.

Journal of Applied Physiology, 2002

The volume-pressure relationship of the lung was studied in six subjects on changing the gravity vector during parabolic flights and body posture. Lung recoil pressure decreased by ∼2.7 cmH2O going from 1 to 0 vertical acceleration (Gz), whereas it increased by ∼3.5 cmH2O in 30° tilted head-up and supine postures. No substantial change was found going from 1 to 1.8 Gz. Matching the changes in volume-pressure relationships of the lung and chest wall (previous data), results in a decrease in functional respiratory capacity of ∼580 ml at 0 Gz relative to 1 Gz and of ∼1,200 ml going to supine posture. Microgravity causes a decrease in lung and chest wall recoil pressures as it removes most of the distortion of lung parenchyma and thorax induced by changing gravity field and/or posture. Hypergravity does not greatly affect respiratory mechanics, suggesting that mechanical distortion is close to maximum already at 1 Gz. The end-expiratory volume during quiet breathing corresponds to the m...

2019

Background: Pulmonary function is one of the most common practice parameters to know airway and lung health. Any abnormality or imbalance can directly change the pulmonary function.Even different body positioning can change pulmonary function. So in different positioning different physiological parameters are having a direct or indirect effect. Objective- The objective of the study was to find out the pulmonary function in supine, sitting and recline positions and compare the pulmonary function of these positions. Procedure- subjects performed PFT 3 times in sitting, recline and supine positions. outcome measures used were FVC,FEV1,FEV1/FVC,FEF25-75% and PEFR. The result showed that sitting position shows better results than supine and recline position. Conclusion- five subjects shows better result in sitting position than supine and recline position.

Journal of the Japanese Physical Therapy Association, 1998

This study was undertaken to evaluate the postural effect on ventilatory responses during both supine and sitting exercise. Seven healthy men performed two exercise tests utilizing the ramp protocol (20 watts/min) with a cycle ergometer in each position. The results were as follows: The oxygen uptake and the oxygen pulse measured at 180 watts and at anaerobic threshold in the sitting were significantly higher compared with those in the supine position. The average of carbon-dioxide output, minute ventilation and tidal volume at lower exercise intensities showed higher values in the sitting compared with those in the supine position, whereas there were no significant differences for respiratory rate. There was significant difference in the slope of the minute ventilation to carbon-dioxide output plot between sitting and supine position. In conclusion, the higher minute ventilation in the sitting position was mainly performed by higher tidal volume which may counteract the effects of an increase in physiological dead space. The lower slope of the minute ventilation to carbon-dioxide output plot which shows more effective ventilation in the supine position may be due to decreased physiological dead space and higher diffusion capacity.

Physiotherapy Theory and Practice, 2003

Few studies have compared the difference in pulmonary function in normal subjects while sitting in an upright posture as compared to a slumped posture. The purpose of this study was to demonstrate differences in tidal volume (TV), breathing frequency (fb), and minute ventilation (V E ) between these two sitting postures in a population of healthy adults.

2019

Purpose: Dynamic Neuromuscular Stabilization (DNS) approach is developed based on neurodevelopmental kinesiology and reflex-mediated core stabilization concepts. But the outcomes of this approach remain unclear. So changes in some spirometry indices in response to DNS breathing exercises in sedentary students with poor posture will be explored. Methods: In this single-group pretest-posttest study design, we involved 26 male volunteer sedentary students with poor posture. First, a pretest of the spirometry indices (Maximum Voluntary Ventilation (MVV), Forced Expiratory Volume in first second (FEV1), Forced Vital Capacity (FVC), and FEV1/FVC ratio) were done each participant in random order. DNS breathing exercise protocol (six times a week, for six weeks) were trained and after completion of training, the post-test of the same parameters was performed. Descriptive statistical and the paired-sample test were used to analyze. Results: The findings of data analysis indicated that the effect of DNS breathing exercise on respiratory function and significant improvements were observed in post-test compared with pre-test in the following parameters: MVV (178.0±21.5 vs 141.0±30.4 l/min, P<0.001), FEV1 (4.7±0.5 vs 4.0±0.5 L, P<0.001), FVC (5.0±0.7 vs 4.4±0.6 L, P<0.001), and FEV1/FVC (0.95±0.05 vs 0.92±0.07 L, P<0.001). Conclusion: It can be concluded that DNS breathing exercise is an effective protocol to significantly improve respiratory function. Moreover, it can be deduced that DNS breathing exercise with a focus on the Integrated Spinal Stabilizing System (ISSS) and breathing techniques can serve as an effective instructive approach to prevent risks of malalignment. Citation Mohammad Rahimi N, Mahdavinejad R, Attarzadeh Hosseini SR, Negahban H. Effect of Dynamic Neuromuscular Stabilization Breathing Exercises on Some Spirometry Indices of Sedentary Students With Poor Posture. Physical Treatments. 2019; 9(3):169-176. http://dx.

BMC Pulmonary Medicine

Background: Pulmonary function tests (PFTs) are routinely performed in the upright position due to measurement devices and patient comfort. This systematic review investigated the influence of body position on lung function in healthy persons and specific patient groups.

Ventilatory parameters. Compliance of respiratory system (Crs), plateau pressure (Pplat), PEEP, intrinsic PEEP (PEEPi), total PEEP (PEEPtot) were studied in 10 patients, ventilated for acute lung injury (ALI), in 3 body positions: supine (SP), left (LLP) and right lateral (RLP), at PEEP levels (increasing at steps of 3 cm H 2 O from 0 up to 18 cm H 2 O or to the level of PEEP at which a decrease of Crs was observed). Studied para-meters were registered at the level of PEEP, at which maximal Crs was observed. Results. In SP the mean values of Crs were higher by 28% and in Pplat lower by 8% than in LP. The PEEP values, at which Crs were the highest increased by 38% at the change from LLP to SP, by 46% from SP to RLP and by 102% at the change from LLP to RLP. The changes of studied parameters were not dependent on the laterality of radiological opacities in lungs. Conclusion. In the ALI patients the change of body position from SP to LP was connected with a risk of great, difficult to ...