Skip to main content
  • Research article
  • Open access
  • Published:

The effect of body position on pulmonary function: a systematic review



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.


A search to identify English-language papers published from 1/1998–12/2017 was conducted using MEDLINE and Google Scholar with key words: body position, lung function, lung mechanics, lung volume, position change, positioning, posture, pulmonary function testing, sitting, standing, supine, ventilation, and ventilatory change. Studies that were quasi-experimental, pre-post intervention; compared ≥2 positions, including sitting or standing; and assessed lung function in non-mechanically ventilated subjects aged ≥18 years were included. Primary outcome measures were forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC, FEV1/FVC), vital capacity (VC), functional residual capacity (FRC), maximal expiratory pressure (PEmax), maximal inspiratory pressure (PImax), peak expiratory flow (PEF), total lung capacity (TLC), residual volume (RV), and diffusing capacity of the lungs for carbon monoxide (DLCO). Standing, sitting, supine, and right- and left-side lying positions were studied.


Forty-three studies met inclusion criteria. The study populations included healthy subjects (29 studies), lung disease (nine), heart disease (four), spinal cord injury (SCI, seven), neuromuscular diseases (three), and obesity (four). In most studies involving healthy subjects or patients with lung, heart, neuromuscular disease, or obesity, FEV1, FVC, FRC, PEmax, PImax, and/or PEF values were higher in more erect positions. For subjects with tetraplegic SCI, FVC and FEV1 were higher in supine vs. sitting. In healthy subjects, DLCO was higher in the supine vs. sitting, and in sitting vs. side-lying positions. In patients with chronic heart failure, the effect of position on DLCO varied.


Body position influences the results of PFTs, but the optimal position and magnitude of the benefit varies between study populations. PFTs are routinely performed in the sitting position. We recommend the supine position should be considered in addition to sitting for PFTs in patients with SCI and neuromuscular disease. When treating patients with heart, lung, SCI, neuromuscular disease, or obesity, one should take into consideration that pulmonary physiology and function are influenced by body position.

Peer Review reports


Pulmonary function tests (PFTs) provide objective, quantifiable measures of lung function. They are used to evaluate and monitor diseases that affect heart and lung function, to monitor the effects of environmental, occupational, and drug exposures, to assess risks of surgery, and to assist in evaluations performed before employment or for insurance purposes. Spirometric examination is the most common form of PFT [1]. According to ATS/ERS guidelines, PFTs may be performed either in the sitting or standing position, and the position should be recorded on the report. Sitting is preferable for safety reasons to avoid falling due to syncope [2], and might also be more convenient because of the measurement devices and patient comfort. However, people who suffer from neuromuscular disease, morbid obesity, and other conditions may find it difficult to sit or stand during this test, which may influence their results.

One of the main goals of positioning, and specifically the use of upright positions, is to improve lung function in patients with respiratory disorders, heart failure, neuromuscular disease, spinal cord injury (SCI), and obesity, and in the past 20 years, various studies regarding the influence of body position on respiratory mechanics and/or function have been published. However, we did not find a systematic review that integrates findings from studies involving non-mechanically ventilated adults to derive clinical implications for respiratory care and pulmonary function test (PFT) execution.

We aimed to systematically review studies that evaluated the effect of body position on lung function in healthy subjects and non-mechanically ventilated patients with lung disease, heart disease, SCI, neuromuscular disease, and obesity.


Two researchers (SK., E-LM.) searched MEDLINE and Google Scholar for studies published from January 1998–December 2017 using the key words body position, lung function, lung mechanics, lung volumes, position change, positioning, posture, PFTs, sitting, standing, supine, ventilation, and ventilatory change, in various combinations. Each search term combination included at least one key word related to pulmonary function and at least one related to body position. The year 1998 was chosen as the beginning point due to the publication of the seminal study by Meysman and Vincken [3]. A total of 972 abstracts identified in the search were screened by the same two researchers, and full text of 151 potentially relevant articles was obtained. The full texts were evaluated and categorized, and 108 articles not fulfilling the inclusion criteria were excluded (Fig. 1).

Fig. 1
figure 1

Study flow diagram

Articles were included if they met the following criteria: (1) Quasi-experimental, pre-post intervention. (2) Two or more body positions compared, including at least the sitting or standing position. (3) Outcome measures included assessment of lung function by forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, vital capacity (VC), functional residual capacity (FRC), maximal expiratory pressure (PEmax), maximal inspiratory pressure (PImax), peak expiratory flow (PEF), total lung capacity (TLC), residual volume (RV), or diffusing capacity of the lungs for carbon monoxide (DLCO). (4) Study population of non-mechanically ventilated subjects. (5) Participants aged ≥18 years. (6) English language. Studies assessing lung function using other criteria and those without statistical comparisons of lung function in different positions, those enrolling individuals < 18 years or on mechanical ventilation, published conference abstracts, and systematic reviews were excluded.

Positions studied

  1. 1.

    Standing – unsupported active standing

  2. 2.

    Sitting – sitting on a chair or wheelchair with the backrest at 90° and all limbs supported

  3. 3.

    Supine – lying flat on the back

  4. 4.

    Right-side lying (RSL) – lying straight on the right side

  5. 5.

    Left-side lying (LSL) – lying straight on the left side

Outcome measures and defined thresholds for clinical significance

  1. 1.

    FVC – forced vital capacity

    • Change of 200 ml or 12% from baseline values in FVC [4]

  2. 2.

    FEV1– forced expiratory volume in 1 s

    • Change of 200 ml or 12% from baseline values in FEV1 [4]

  3. 3.

    FEV1/FVC – forced expiratory volume in 1 s divided by forced vital capacity

    • FEV1/FVC < 0.7 is defined as obstructive disease

  4. 4.

    VC – vital capacity

  5. 5.

    FRC – functional residual capacity

    • Change > 10% [5]

  6. 6.

    TLC – total lung capacity

    • Change > 10% [5]

  7. 7.

    RV – residual volume

  8. 8.

    Maximal expiratory pressure (PEmax)

    • Change ≥24 cmH2O [6,7,8]

  9. 9.

    Maximal inspiratory pressure (PImax)

    • Change ≤ − 13 cmH2O [6,7,8]

  10. 10.

    Peak expiratory flow (PEF)

    • Change > 10% or 60 L/min [9, 10]

  11. 11.

    Diffusing capacity of the lungs for carbon monoxide (DLCO)

    • Change ≥10% in DLCO [11, 12]

Two experienced pulmonologists (NA, AR) reviewed the included studies in consensus to identify statistically significant and clinically important differences in pulmonary function. Results from articles included in the review were evaluated by all authors and categorized by study population, body positions studied, and outcome measures. Data from included studies was extracted by four authors (NA, AR, SK, E-LM.) independently and in consultation when questions arose. The review was performed according to the PRISMA guidelines [13].

Although these are not interventional studies, strictly speaking, we have chosen to assess them as “before and after intervention,” wherein the posture/position change is the maneuver of interest. Level of evidence was assessed according to the American Academy of Neurology (AAN) Classification of Evidence for therapeutic intervention [14]. Risk of bias was assessed according to the Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group developed by the National Heart, Lung and Blood Institute (NHLBI) of the US National Institutes of Health (NIH) [15]. This tool is comprised of 12 questions assessing various aspects of the quality of the study. Two authors (E-LM, SK) independently scored each study using the technique from Kunstler et al. [16]. Differences were resolved in consensus, in consultation with a third author (YZ). The risk of bias was categorized as low (score 76–100%), moderate (26–75%) or high (0–25%).


Studies included in the review

A total of 43 studies fully met inclusion criteria and were included in the review (Fig. 1). All studies used either consecutive, convenience, or volunteer sampling to enroll healthy individuals or subjects with various medical conditions. All studies provide Class III level of evidence.

The protocols and level of bias in the various studies are shown in Table 1 and Additional file 1: Table S1. Risk of bias was assessed as moderate in 41 studies and low in two. Quality issues were primarily related to sampling techniques for enrolling study participants. All studies used non-random sampling. Some studies investigating healthy subjects included convenience samples of young participants, mainly students. Only 7/43 studies reported sample size calculations required to reach statistical power. In addition, the details of the intervention protocol were not clearly reported in some studies (Table 1) and due to the nature of the study assessors could not be blinded to patient position or outcomes from previous tests.

Table 1 Study protocols

A summary of study characteristics, including the positions studied, outcome measures, and main results according to the study population, is shown in Table 2. Out of 43 studies, 29 included healthy subjects, nine included patients with lung disease, four included patients with heart disease, seven included patients with SCI, three included patients with neuromuscular diseases, and four included patients with obesity. Additional file 2: Table S2 summarizes only the statistically significant findings for each relevant outcome variable, according to position, for each of the populations studied.

Table 2 Summary of study characteristics according to study population


The association between FVC and body position in healthy subjects was investigated in 13 studies [3, 17,18,19,20,21,22,23,24,25,26,27,28]. There was a clinical and statistically significant increase in FVC in sitting vs. supine positions [3, 18, 22,23,24,25,26,27], in sitting vs. RSL and LSL [3, 21], standing vs. supine [19, 23], and standing vs. RSL and LSL [19]. In a smaller number of studies there was no change between standing and sitting [19], sitting and supine [17, 21, 28] or sitting and RSL or LSL [21], and one study [22] found a decrease in FVC from sitting to standing that was statistically but not clinically significant. Thus, in the majority of studies the more upright position was associated with increased FVC.

Four studies included subjects with lung disease [29,30,31,32]. Among asthmatic patients in one study FVC increased significantly from supine to standing [30]; however, there was no significant difference between standing and sitting or between sitting and supine, RSL, or LSL. Another study reported a statistically and clinically significant increase in FVC in standing vs. sitting, supine, RSL, and LSL and in sitting vs. supine, RSL and LSL [31]. Among obese asthmatic patients [32], and among patients with chronic obstructive pulmonary disease (COPD) [29], no difference was found in FVC between standing and sitting.

Three studies included subjects with congestive heart failure (CHF) [18, 21, 27]. In one study, FVC was reported 200 ml higher in sitting vs. RSL and LSL [21], and in the other two studies FVC was higher in sitting vs. supine by 350–400 ml, which has clinical significance [18, 27].

Six studies included patients with SCI [17, 33,34,35,36,37]. The effect of body position on FVC depends on the level and extent of injury. Among those with cervical SCI, FVC was higher in the supine vs. sitting position [17, 33, 34]. Other studies [35,36,37] did not find significant differences in FVC for patients with SCI in a pooled group of all levels of injury for these positions. However, in patients with cervical SCI, as well as those with thoracic injury in one study [36], there was an increased FVC in the supine vs. sitting, while in those with thoracic or lumbar injury FVC was higher in the sitting position [37]. The differences did not always reach statistical significance. Nevertheless, it is important to note that in these debilitated patients with SCI, even a small change in FVC is probably clinically significant.

Three studies evaluated patients with neuromuscular diseases [25, 34, 38]. In patients with myotonic dystrophy and in those with amyotrophic lateral sclerosis (ALS), there was a clinically and statistically significant decrease in FVC from sitting to supine [25, 34, 38]. In subjects with obesity (mean BMI 36.7) no significant difference was reported between standing and sitting [32].


In healthy subjects, FEV1 was reported to be higher in sitting vs. supine [3, 18, 22, 23, 26, 27, 39], in sitting vs. RSL and LSL [3, 19, 20], in standing vs. sitting [23], and in standing vs. sitting, supine, RSL, and LSL [19]. However, other studies [21, 24, 28, 40] did not find significant difference for FEV1 between sitting and supine, RSL, and LSL. One study [22] reported a decrease of 120 ml in FEV1 from sitting to standing, which is statistically but not clinically significant.

Among asthmatic patients, FEV1 was higher in the standing vs. supine position, a statistically and clinically significant change; however, there was no significant difference between sitting vs. supine, RSL, and LSL positions [30]. Another study in asthmatic patients reported FEV1 to be higher in standing vs. sitting, supine, RSL, and LSL, and in sitting  vs. supine, RSL and LSL [31]. Among obese asthmatic patients and those with COPD, there was no significant difference in FEV1 between standing and sitting [29, 32].

In subjects with CHF, one study found a statistically and clinically significant increase in FEV1 in sitting vs. RSL and LSL, but no difference between sitting and supine [21], while two other studies reported higher FEV1 in sitting vs. supine [18, 27].

In patients with SCI, FEV1 was recently reported to increase from sitting to supine [40]; however, other studies found that the effect of position on FEV1 in those with SCI depends on the level and extent of injury. In one study among all subjects with SCI, FEV1 was not significantly influenced by moving from sitting to supine [35], but patients with cervical injuries showed a tendency for increased FEV1 in the supine vs. sitting position while those with thoracic injuries tended towards increased FEV1 in the sitting position. Along the same vein, another study [36] found an increase is FEV1 in the sitting vs. the supine position in patients with lumbar injury while FEV1 was higher in the supine position for those with cervical spine or thoracic injuries. Although the differences between positions were not statistically significant, the effect of level of injury was statistically and clinically significant.

In another study [33], FEV1 was higher in supine vs. sitting in patients with complete tetraplegia, while in patients with incomplete injury there was no significant difference between positions. Another group [37] reported no significant change in FEV1 between the sitting and supine positions for a pooled group of patients with SCI, but in the subgroup of patients with incomplete motor injury and in those with incomplete thoracic motor injury there was a decrease in the supine position.

In patients with myotonic dystrophy, FEV1 decreased from sitting to supine [38]. Among those with obesity, FEV1 was higher in sitting vs. supine both before and after bariatric surgery [41]. In another study among obese patients, there was no difference in FEV1 between standing and sitting [32].


Seven studies compared FEV1/FVC for different body positions in healthy subjects [18, 19, 23, 24, 27, 28, 42]. In several studies, FEV1/FVC was reported to be higher in sitting vs. supine [23, 28], in sitting vs. LSL [19], and in standing vs. supine, RSL, and LSL [19]; however, FEV1/FVC was > 70% in all body positions so the difference was not clinically significant. Other studies found no difference between sitting and supine [18, 24, 27] or standing, sitting, and supine [42].

Among subjects with asthma, CHF, and obesity no statistically significant difference in FEV1/FVC was found between the different body postures [18, 27, 32, 42].

Vital capacity

The effect of body position on vital capacity was evaluated in six studies of healthy subjects [21, 24, 28, 39, 43, 44]. In most studies no difference was reported between sitting and supine [21, 24, 28, 43] or between sitting and RSL or LSL [21]. One study [39] found that VC was higher in the sitting vs. supine position. However, another study [44] found that VC was higher in the supine vs. sitting position, but only in females.

In patients with CHF, VC was reported to be higher in sitting vs. supine in one study [27] while another study found no statistically significant difference between these positions [21]. In patients with spinal cord injury, VC was higher in the supine vs. sitting position [40]. In subjects with obesity, no difference in VC was reported between the sitting and supine positions [41, 43].


PEF in different body positions was evaluated in 13 studies [3, 22,23,24, 31, 33, 45,46,47,48,49,50,51]. Eight studies evaluated only healthy adults [3, 22,23,24, 45, 48, 50, 51], three evaluated healthy subjects and patients with COPD or asthma [31, 46, 49], one included adult cystic fibrosis patients [47], and one included subjects with SCI [33]. Nine studies that compared standing or sitting positions vs. supine or RSL and LSL found higher PEF in standing and sitting [3, 22,23,24, 31, 45,46,47,48]. Three of six studies comparing the standing and sitting positions found higher PEF in standing [46, 50, 51] and one reported higher PEF in sitting [22]. However, it is most likely that none of the differences reported in PEF are clinically significant. In SCI patients with complete tetraplegia PEF was found to be 12% higher in the supine vs. sitting position [33].


FRC was evaluated using helium dilution in five studies [27, 41, 43, 52, 53]. Among healthy subjects, FRC was higher in standing [53] and in sitting [27, 43] vs. supine, with the differences reaching statistical and clinical significance. However, the difference in sitting vs. supine was not significant among patients with obesity (mean BMI 44–45) [41, 43] or CHF [27], and was higher in sitting vs. supine in patients after bariatric surgery (mean BMI 31) [41]. Another study [52] involving subjects with mild-to-moderate obesity (mean BMI 32), reported that FRC was significantly higher both statistically and clinically in sitting vs. supine.

Total lung capacity

Two studies that evaluated TLC using helium dilution in healthy subjects [43] and in subjects with obesity [41, 43] found no statistically significant difference between the sitting and supine positions.

Residual volume

Two studies that evaluated RV using helium dilution in healthy subjects [43] and those with obesity [41, 43] found no statistically significant difference between sitting and supine.


Six studies investigated the association between body position and PEmax in healthy subjects [3, 28, 39, 46, 54, 55]. PEmax was higher in standing vs. supine, in standing vs. sitting and RSL, in sitting vs. supine [54], and in sitting vs. supine and RSL [46]; however, the differences reported in those studies were not clinically significant. Other studies found no difference in PEmax between sitting and supine [28, 39], or between sitting, supine, RSL, and LSL [3, 55].

In COPD patients, PEmax was higher in standing or sitting vs. supine or RSL [46], and was higher in standing and sitting vs. RSL in patients with cystic fibrosis [47]. The differences were not clinically significant.

In subjects with SCI, PEmax was significantly higher in sitting vs. supine for all subjects, and for patients with motor complete injury or incomplete cervical motor injury [37].


In healthy subjects, PImax was improved in sitting vs. supine in two studies [3, 54]. However, other studies found no difference in PImax in sitting vs. supine [28, 39, 55], or sitting vs. RSL and LSL [3, 55]. In subjects with chronic SCI, no significant change was seen in PImax between sitting and supine, with the exception of a subgroup of patients with complete thoracic motor paresis where there was statistically and clinically significant improvement in sitting [37].


Seven studies evaluated the effect of body position on diffusion capacity; six included healthy subjects [18, 20, 21, 24, 56, 57], three included patients with CHF [18, 21, 58], and one included COPD patients [57].

Among healthy subjects, two studies [24, 56] found statistically and clinically significant improvement in DLCO in supine vs. sitting and one [57] found a trend towards increased DLCO in supine vs. sitting, however this difference did not reach statistical significance. One study [18] found DLCO to be higher in the sitting vs. supine positions while another study found no difference in DLCO between these positions [21]. One study [21] reported higher DLCO in sitting vs. side lying while another study [20] found no difference between these positions. In COPD patients, no statistically significant change in DLCO was found between the sitting and the supine position [57].

Three studies investigated diffusion capacity in patients with CHF [18, 21, 58]. One study [58] found that postural changes from the supine to sitting positions induced different responses in diffusion capacity. In some patients diffusion capacity improved in the sitting position and others showed no change or a decline. On the average no statistically significant difference was found between the two positions. The authors attributed the difference in responses to variations in pulmonary circulation pressures. Another study [18] found no significant difference in diffusion capacity between the sitting and the supine positions. Side-lying was reported to reduce DLCO in comparison to sitting in the third study [21].


Most studies in this systematic review of 43 papers evaluating the effect of body position on pulmonary function found that pulmonary function improved with more erect posture in both healthy subjects and those with lung disease, heart disease, neuromuscular diseases, and obesity. In patients with SCI, the effect is more complex and depends on the severity and level of injury. In contrast, diffusion capacity, as assessed by DLCO, increases in the supine position in healthy subjects while the effect in CHF patients is thought to depend upon pulmonary circulation pressure.

Decreased FVC in more recumbent positions may reflect both increased thoracic blood volume due to gravitational facilitation of venous return, which is more important in patients with heart failure, as well as cephalic displacement of the diaphragm due to abdominal pressure in the recumbent positions, which is more important in obese subjects [59]. In side-lying positions, even though only the dependent hemi-diaphragm is displaced, the effect on FVC appears to be similar to that observed in a supine position [59]. Other factors that may contribute to lower FVC values in side-lying positions include increased airway resistance and decreased lung compliance secondary to anatomical differences between the left and right lungs, as well as shifting of the mediastinal structures [20].

FEV1 was also higher in erect positions. Recumbent positions limit expiratory volumes and flow, which may reflect an increase in airway resistance, a decrease in elastic recoil of the lung, or decreased mechanical advantage of forced expiration, presumably affecting the large airways [20]. In asthmatic patients the increase in FVC while standing might be due to the increased diameter of the airways in this position [30].

In patients with CHF the lungs are stiff and heavy, and the heart is large and heavy, increasing the negative effects of lung-heart interdependence [60]. As cardiac dimension increases, lung volume, mechanical function, and diffusion capacity decrease [61, 62]; thus, the heart weighs on the diaphragm while sitting and on one of the lungs while in a side-lying position. This influences the ability of the lungs to expand laterally but allows the diaphragm to descend and the lungs to expand inferiorly. In side-lying positions, the heart weighs on one lung, compressing both the airways and lung parenchyma, leading to a reduction in FEV1 and FVC due to airway compression [21]. Both elastic (reduced lung compliance) and resistive loads are simultaneously increased in the supine position in CHF patients [63].

Changes in FVC from the sitting to supine positions may reflect diaphragm strength/paralysis. FVC is thus an important clinical tool for assessment of diaphragmatic weakness in patients with neuromuscular diseases [64]. In patients with ALS, supine FVC is a test of diaphragmatic weakness [65] that predicts orthopnea [25] and prognosis for survival [66, 67]. The American Academy of Neurology has concluded that in ALS patients, supine FVC is probably more effective than erect FVC in detecting diaphragm weakness and correlates better with symptoms of hypoventilation [68].

In patients with cervical SCI (tetraplegia), FVC and FEV1 increase in the supine vs. sitting position. The diaphragm increases its inspiratory excursion in the supine position because its muscle fibers are longer at end expiration, and they operate at a more effective point of their length-tension curve [69,70,71]. This mechanism is especially important in patients for whom the diaphragm is the main muscle for breathing, since their intercostal and abdominal muscles are inactive due to SCI.

FRC was reported to increase in upright positions in healthy subjects [27, 43, 53] and in patients with mild-to-moderate obesity [41, 52]. Changing from a supine to an upright position increases FRC due to reduced pulmonary blood volume and the descent of the diaphragm. This may change the point in which tidal breathing occurs in the volume-pressure curve, which leads to increased lung compliance, and thus an identical pressure change would produce a greater inspired volume if there is no change in respiratory drive [53]. However, among patients with CHF, no difference in FRC between sitting and supine was reported [27]. In heart failure, reduction in lung compliance in the supine position might reduce the passive change in lung volume, but FRC may be sustained above relaxation volume by an adjustment in respiratory muscle or glottal activity [27]. Among patients with obesity the sitting FRC was less than in healthy subjects but there was no further decrease in the supine position [43].

PEF, PEmax, and PImax were found to increase in upright positions in healthy subjects [3, 23, 24, 46, 48, 50, 51] and in those with lung diseases [31, 46, 47]. This may be related to changes in lung volumes with positions.

Standing and sitting have been shown to lead to the highest lung volumes [72, 73]. At higher lung volumes the elastic recoil of the lungs and the chest wall is greater. In addition, the expiratory muscles are at a more optimal region of the length-tension curve and thus are capable of generating higher intrathoracic pressure, potentially generating higher expiratory pressures and pushing air through narrow airways at high speed, which results in higher PEmax, PEF, and FEV1. As lung volumes decrease, muscle length becomes less optimal, which results in lower PEmax in sitting, compared to the standing position, and even lower in more recumbent positions. The change in PEmax influences PEF [46].

When standing, gravity pulls the mediastinal and abdominal structures down, creating more space in the thoracic cavity, which allows further expansion of the lungs and greater lung volumes [74]. This, along with the decrease in compression on the lung bases, allows alveoli to recruit and increases lung compliance. The inspiratory muscles can expand even more, which allows the diaphragm to continue contracting downwards, thus increasing lung volumes [46].

Sitting often leads to the somewhat reduced lung volumes compared with standing. This can be explained by several mechanisms. First, in sitting, abdominal organs are higher, interfering with diaphragmatic motion, thus enabling smaller inspiration. Second, the abdominal muscles are in a less optimal point in the length-tension curve, since the combination of hip flexion and higher position of the abdominal contents exert upward pressure. Third, the back of the chair may limit thoracic expansion. These three factors explain a slightly lower PEmax and PEF in sitting vs. standing [46].

Diaphragmatic strength is negatively affected by the supine position, and intrathoracic blood volume is increased. These factors lead to decreased PEmax and PEF in the supine position [3].

In side-lying positions (RSL or LSL), when the bed is flat, the abdominal contents fall forward. The dependent hemi-diaphragm is stretched to a good length for tension generation, while the nondependent hemi-diaphragm is more flattened. Changes in lung volumes may thus balance themselves out due to a better diaphragmatic contraction but decreased space in the thorax [46].

The decreased PImax observed in the supine position could be related to diaphragm overload by abdominal content displacement during maximal inspiratory effort, which could offset improved diaphragm position on the length-tension curve. In addition, the length of all other inspiratory muscles may become less optimal in supine position [75].

In patients with cervical spinal cord injury and high tetraplegia, PEF was found to be higher in the supine vs. sitting position [33] corresponding to the increase in FVC and FEV1 in the supine position.

In healthy subjects, most studies showed an increase in DLCO in supine vs. sitting [24, 56, 57]. This improvement is attributed to the moderate increase in alveolar blood volume in the supine position due to recruitment of lung capillary bed on transition from upright to supine. Age may attenuate this increase [76]. This may explain why a study that included participants with a mean age of 61 [21] found no difference in DLCO between sitting and supine.

In side-lying positions, the heart weighs on one lung, compressing both airways and lung parenchyma, reducing alveolar blood volume, and causing ventilation/ perfusion mismatch. Those effects caused reduction of diffusion capacity in the side-lying positions [21].

In COPD patients, there was no change in DLCO between sitting and supine [57]. This might be related to reduced FVC and alveolar damage in these patients. These effects might have negative impact on diffusion capacity, opposing the positive effect of the increase in blood volume in the alveoli [57].

In patients with CHF, different patterns of the effect of posture on DLCO were observed [58]. The change in DLCO was probably related to the change in alveolar blood volume, most likely due to differences in pulmonary artery pressure and heart dimensions [58].

Limitations of the study

There are a few limitations to this review. First, the level of evidence of the studies is relatively low. However, in this type of research, due to the nature of the populations studied and the interventions applied, it is impossible to perform a randomized control study. Second, most studies were performed on a small number of subjects and all studies used either consecutive, convenience, or volunteer sampling. The review included only adult subjects and it is therefore not possible to generalize the results to children and adolescents. Finally, research protocols varied between studies and detailed information about protocols were often missing. Patient cooperation during lung function testing strongly influences results. This may explain contradictory results obtained in some cases. Studies that included subjects older than 60 years did not mention the cognitive function of participants, a factor that may influence patient cooperation.

Further research in this field is needed, including studies designed to evaluate lung function in a larger number of healthy participants as well as in individuals with a variety of medical conditions. There is also a need to use a standardized protocol including randomization of postures and times between tests (e.g. for wash-out of inhaled gasses or redistribution of blood volume) in different positions to enable a better comparison of outcomes.


When performing pulmonary function tests, body position plays a role in its influence over test results. As seen in this review, a change in body position may have varying implications depending on the patient populations. American Thoracic Society (ATS) guidelines [2] recommend performing PFTs in the sitting or standing position, but the sitting position is usually preferred. The norms of those functions according to gender and age were established from tests performed in this position. This review suggests that for most of the subjects this is the preferred position for the test; however, clinicians should consider performing PFTs in other positions in selected patients. In patients with SCI, testing also in the supine position may provide important information. In patients with neuromuscular disorders, performing PFTs in the supine position may help to assess diaphragmatic function.

Positioning plays an important role in maximizing respiratory function when treating patients with various problems and diseases and it is important to know the implications of each position on the respiratory system of a specific patient. Understanding the influence of body position can give healthcare professionals better knowledge of optimal positions for patients with different diseases.



American Academy of Neurology


Amyotrophic lateral sclerosis


American Thoracic Society


Congestive heart failure


Chronic obstructive pulmonary disease


Diffusing capacity of the lungs for carbon monoxide


European Respiratory Society


Forced expiratory volume in 1 s


Functional residual capacity


Forced vital capacity


Left side lying


Peak expiratory flow


Maximal expiratory pressure


Pulmonary function test


Maximal inspiratory pressure


Right side lying


Residual volume


Spinal cord injury


Total lung capacity


Vital capacity


  1. Crapo RO. Pulmonary-function testing. N Engl J Med. 1994;331(1):25–30.

    Article  CAS  Google Scholar 

  2. Miller MR, Crapo R, Hankinson J, et al. General considerations for lung function testing. Eur Respir J. 2005;26(1):153–61.

    Article  CAS  Google Scholar 

  3. Meysman M, Vincken W. Effect of body posture on spirometric values and upper airway obstruction indices derived from the flow-volume loop in young nonobese subjects. Chest. 1998;114(4):1042–7.

    Article  CAS  Google Scholar 

  4. Pellegrino R, Viegi G, Brusasco V, et al. Interpretative strategies for lung function tests. Eur Respir J. 2005;26(5):948–68.

    Article  CAS  Google Scholar 

  5. Wanger J, Clausen JL, Coates A, et al. Standardisation of the measurement of lung volumes. Eur Respir J. 2005;26(3):511–22.

    Article  CAS  Google Scholar 

  6. Goswami R, Guleria R, Gupta AK, et al. Prevalence of diaphragmatic muscle weakness and dyspnoea in Graves’ disease and their reversibility with carbimazole therapy. Eur J Endocrinol. 2002;147(3):299–303.

    Article  CAS  Google Scholar 

  7. Keenan SP, Alexander D, Road JD, Ryan CF, Oger J, Wilcox PG. Ventilatory muscle strength and endurance in myasthenia gravis. Eur Respir J. 1995;8(7):1130–5.

    Article  CAS  Google Scholar 

  8. Nava S, Crotti P, Gurrieri G, Fracchia C, Rampulla C. Effect of a beta 2-agonist (broxaterol) on respiratory muscle strength and endurance in patients with COPD with irreversible airway obstruction. Chest. 1992;101(1):133–40.

    Article  CAS  Google Scholar 

  9. Quanjer PH, Lebowitz MD, Gregg I, Miller MR, Pedersen OF. Peak expiratory flow: conclusions and recommendations of a working Party of the European Respiratory Society. Eur Respir J Suppl. 1997;24:2s–8s.

    CAS  PubMed  Google Scholar 

  10. Global initiative for asthma (GINA): Global strategy for asthma management and prevention (2018 update). 2018. file:///C:/Users/owner/Downloads/wms-GINA-2018-report-V1.3–002.pdf. Accessed 29 May 2018.

    Google Scholar 

  11. Graham BL, Brusasco V, Burgos F, et al. 2017 ERS/ATS standards for single-breath carbon monoxide uptake in the lung. Eur Respir J. 2017;49(1).

    Article  Google Scholar 

  12. Hathaway EH, Tashkin DP, Simmons MS. Intraindividual variability in serial measurements of DLCO and alveolar volume over one year in eight healthy subjects using three independent measuring systems. Am Rev Respir Dis. 1989;140(6):1818–22.

    Article  CAS  Google Scholar 

  13. Moher D, Liberati A, Tetzlaff J, Altman DG, PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(7):e1000097.

    Article  Google Scholar 

  14. Gronseth GS, Woodroffe LM, Getchuis TSD. Clinical practice guideline process manual. 2011. Accessed 29 May 2018.

  15. Quality assessment tool for before-after (pre-post) studies with no control group. 2014. Accessed 12 Aug 2018.

  16. Kunstler BE, Cook JL, Freene N, et al. Physiotherapist-led physical activity interventions are efficacious at increasing physical activity levels: a systematic review and meta-analysis. Clin J Sport Med. 2018;28(3):304–15.

    Article  Google Scholar 

  17. Ben-Dov I, Zlobinski R, Segel MJ, Gaides M, Shulimzon T, Zeilig G. Ventilatory response to hypercapnia in C(5-8) chronic tetraplegia: the effect of posture. Arch Phys Med Rehabil. 2009;90(8):1414–7.

    Article  Google Scholar 

  18. Ceridon ML, Morris NR, Olson TP, Lalande S, Johnson BD. Effect of supine posture on airway blood flow and pulmonary function in stable heart failure. Respir Physiol Neurobiol. 2011;178(2):269–74.

    Article  Google Scholar 

  19. Ganapathi LV, Vinoth S. The estimation of pulmonary functions in various body postures in normal subjects. Int J Advances Med. 2015;2(3):250–4 Accessed 29 May 2018.

    Article  Google Scholar 

  20. Manning F, Dean E, Ross J, Abboud RT. Effects of side lying on lung function in older individuals. Phys Ther. 1999;79(5):456–66.

    CAS  PubMed  Google Scholar 

  21. Palermo P, Cattadori G, Bussotti M, Apostolo A, Contini M, Agostoni P. Lateral decubitus position generates discomfort and worsens lung function in chronic heart failure. Chest. 2005;128(3):1511–6.

    Article  Google Scholar 

  22. Patel AK, Thakar HM. Spirometric values in sitting, standing, and supine position. Lung Pulm Resp Res. 2015;2(1):00026 Accessed 29 May 2018.

    Google Scholar 

  23. Saxena J, Gupta S, Saxena S. A study of change of posture on the pulmonary function tests : can it help COPD patients? Indian J Community Health. 2006;18(1):10–2. Accessed 29 May 2018.

  24. Stewart IB, Potts JE, McKenzie DC, Coutts KD. Effect of body position on measurements of diffusion capacity after exercise. Br J Sports Med. 2000;34(6):440–4.

    Article  CAS  Google Scholar 

  25. Varrato J, Siderowf A, Damiano P, Gregory S, Feinberg D, McCluskey L. Postural change of forced vital capacity predicts some respiratory symptoms in ALS. Neurology. 2001;57(2):357–9.

    Article  CAS  Google Scholar 

  26. Vilke GM, Chan TC, Neuman T, Clausen JL. Spirometry in normal subjects in sitting, prone, and supine positions. Respir Care. 2000;45(4):407–10.

    CAS  PubMed  Google Scholar 

  27. Yap JC, Moore DM, Cleland JG, Pride NB. Effect of supine posture on respiratory mechanics in chronic left ventricular failure. Am J Respir Crit Care Med. 2000;162(4 Pt 1):1285–91.

    Article  CAS  Google Scholar 

  28. Tsubaki A, Deguchi S, Yoneda Y. Influence of posture on respiratory function and respiratory muscle strength in normal subjects. J Phys Ther Sci. 2009;21(1):71–4 Accessed 29 May 2018.

    Article  Google Scholar 

  29. De S. Comparison of spirometric values in sitting versus standing position among patients with obstructive lung function. Indian J Allergy Asthma Immunol. 2012;26(2):86–8 Accessed 29 May 2018.

    Article  Google Scholar 

  30. Melam GR, Buragadda S, Alhusaini A, Alghamdi MA, Alghamdi MS, Kaushal P. Effect of different positions on FVC and FEV1 measurements of asthmatic patients. J Phys Ther Sci. 2014;26(4):591–3.

    Article  Google Scholar 

  31. Mohammed J, Abdulateef A, Shittu A, Sumaila FG. Effect of different body positioning on lung function variables among patients with bronchial asthma. Arch Physiother Global Res. 2017;21(3):7–12. Accessed 29 May 2018.

  32. Razi E, Moosavi GA. The effect of positions on spirometric values in obese asthmatic patients. Iran J Allergy Asthma Immunol. 2007;6(3):151–4.

    PubMed  Google Scholar 

  33. Linn WS, Adkins RH, Gong H Jr, Waters RL. Pulmonary function in chronic spinal cord injury: a cross-sectional survey of 222 southern California adult outpatients. Arch Phys Med Rehabil. 2000;81(6):757–63.

    Article  CAS  Google Scholar 

  34. Park JH, Kang SW, Lee SC, Choi WA, Kim DH. How respiratory muscle strength correlates with cough capacity in patients with respiratory muscle weakness. Yonsei Med J. 2010;51(3):392–7.

    Article  Google Scholar 

  35. Baydur A, Adkins RH, Milic-Emili J. Lung mechanics in individuals with spinal cord injury: effects of injury level and posture. J Appl Physiol. 2001;90(2):405–11.

    Article  CAS  Google Scholar 

  36. Kim M-K, Hwangbo G. The effect of position on measured lung function in patients with spinal cord injury. J Physical Therapy Sci. 2012;24(8):655–7 Accessed 29 May 2018.

  37. Terson de Paleville DG, Sayenko DG, Aslan SC, Folz RJ, McKay WB, Ovechkin AV. Respiratory motor function in seated and supine positions in individuals with chronic spinal cord injury. Respir Physiol Neurobiol. 2014;203:9–14.

    Article  Google Scholar 

  38. Poussel M, Kaminsky P, Renaud P, Laroppe J, Pruna L, Chenuel B. Supine changes in lung function correlate with chronic respiratory failure in myotonic dystrophy patients. Respir Physiol Neurobiol. 2014;193:43–51.

    Article  Google Scholar 

  39. Naitoh S, Tomita K, Sakai K, Yamasaki A, Kawasaki Y, Shimizu E. The effect of body position on pulmonary function, chest wall motion, and discomfort in young healthy participants. J Manipulative Physiol Ther. 2014;37(9):719–25.

    Article  Google Scholar 

  40. Miccinilli S, Morrone M, Bastianini F, et al. Optoelectronic plethysmography to evaluate the effect of posture on breathing kinematics in spinal cord injury: a cross sectional study. Eur J Phys Rehabil Med. 2016;52(1):36–47.

    PubMed  Google Scholar 

  41. Sebbane M, El Kamel M, Millot A, et al. Effect of weight loss on postural changes in pulmonary function in obese dubjects: a longitudinal study. Respir Care. 2015;60(7):992–9.

    Article  Google Scholar 

  42. Myint WW, Htay MNN, Soe HHK, et al. Effect of body positions on lungs volume in asthmatic patients: a cross-sectinal study. J Adv Med Pharma Sci. 2017;13(4):1–6 Accessed 29 May 2018.

    Google Scholar 

  43. Watson RA, Pride NB. Postural changes in lung volumes and respiratory resistance in subjects with obesity. J Appl Physiol (1985). 2005;98(2):512–7.

    Article  CAS  Google Scholar 

  44. Roychowdhury P, Pramanik T, Prajapati R, Pandit R, Singh S. In health--vital capacity is maximum in supine position. Nepal Med Coll J. 2011;13(2):131–2.

    CAS  PubMed  Google Scholar 

  45. Antunes BO, de Souza HC, Gianinis HH, Passarelli-Amaro RC, Tambascio J, Gastaldi AC. Peak expiratory flow in healthy, young, non-active subjects in seated, supine, and prone postures. Physiother Theory Pract. 2016;32(6):489–93.

    Article  Google Scholar 

  46. Badr C, Elkins MR, Ellis ER. The effect of body position on maximal expiratory pressure and flow. Aust J Physiother. 2002;48(2):95–102.

    Article  Google Scholar 

  47. Elkins MR, Alison JA, Bye PT. Effect of body position on maximal expiratory pressure and flow in adults with cystic fibrosis. Pediatr Pulmonol. 2005;40(5):385–91.

    Article  Google Scholar 

  48. Gianinis HH, Antunes BO, Passarelli RC, Souza HC, Gastaldi AC. Effects of dorsal and lateral decubitus on peak expiratory flow in healthy subjects. Braz J Phys Ther. 2013;17(5):435–41.

    Article  Google Scholar 

  49. McCoy EK, Thomas JL, Sowell RS, et al. An evaluation of peak expiratory flow monitoring: a comparison of sitting versus standing measurements. J Am Board Fam Med. 2010;23(2):166–70.

    Article  Google Scholar 

  50. Ottaviano G, Scadding GK, Iacono V, Scarpa B, Martini A, Lund VJ. Peak nasal inspiratory flow and peak expiratory flow. Upright and sitting values in an adult population. Rhinology. 2016;54(2):160–3.

    Article  Google Scholar 

  51. Wallace JL, George CM, Tolley EA, et al. Peak expiratory flow in bed? A comparison of 3 positions. Respir Care. 2013;58(3):494–7.

    PubMed  Google Scholar 

  52. Benedik PS, Baun MM, Keus L, et al. Effects of body position on resting lung volume in overweight and mildly to moderately obese subjects. Respir Care. 2009;54(3):334–9.

    PubMed  Google Scholar 

  53. Chang AT, Boots RJ, Brown MG, Paratz JD, Hodges PW. Ventilatory changes following head-up tilt and standing in healthy subjects. Eur J Appl Physiol. 2005;95(5–6):409–17.

    Article  Google Scholar 

  54. Costa R, Almeida N, Ribeiro F. Body position influences the maximum inspiratory and expiratory mouth pressures of young healthy subjects. Physiotherapy. 2015;101(2):239–41.

    Article  Google Scholar 

  55. Ogiwara S, Miyachi T. Effect of posture on ventilatory muscle strength. J Phys Ther Sci. 2002;14(1):1–5. Accessed 29 May 2018.

    Article  Google Scholar 

  56. Peces-Barba G, Rodriguez-Nieto MJ, Verbanck S, Paiva M, Gonzalez-Mangado N. Lower pulmonary diffusing capacity in the prone vs. supine posture. J Appl Physiol (1985). 2004;96(5):1937–42.

    Article  CAS  Google Scholar 

  57. Terzano C, Conti V, Petroianni A, Ceccarelli D, De Vito C, Villari P. Effect of postural variations on carbon monoxide diffusing capacity in healthy subjects and patients with chronic obstructive pulmonary disease. Respiration. 2009;77(1):51–7.

    Article  Google Scholar 

  58. Faggiano P, D’Aloia A, Simoni P, et al. Effects of body position on the carbon monoxide diffusing capacity in patients with chronic heart failure: relation to hemodynamic changes. Cardiology. 1998;89(1):1–7.

    Article  CAS  Google Scholar 

  59. Behrakis PK, Baydur A, Jaeger MJ, Milic-Emili J. Lung mechanics in sitting and horizontal body positions. Chest. 1983;83(4):643–6.

    Article  CAS  Google Scholar 

  60. Agostoni PG, Marenzi GC, Sganzerla P, et al. Lung-heart interaction as a substrate for the improvement in exercise capacity after body fluid volume depletion in moderate congestive heart failure. Am J Cardiol. 1995;76(11):793–8.

    Article  CAS  Google Scholar 

  61. Agostoni PG, Cattadori G, Guazzi M, Palermo P, Bussotti M, Marenzi G. Cardiomegaly as a possible cause of lung dysfunction in patients with heart failure. Am Heart J. 2000;140(5):e24.

    Article  CAS  Google Scholar 

  62. Hosenpud JD, Stibolt TA, Atwal K, Shelley D. Abnormal pulmonary function specifically related to congestive heart failure: comparison of patients before and after cardiac transplantation. Am J Med. 1990;88(5):493–6.

    Article  CAS  Google Scholar 

  63. Nava S, Larovere MT, Fanfulla F, Navalesi P, Delmastro M, Mortara A. Orthopnea and inspiratory effort in chronic heart failure patients. Respir Med. 2003;97(6):647–53.

    Article  CAS  Google Scholar 

  64. Fromageot C, Lofaso F, Annane D, et al. Supine fall in lung volumes in the assessment of diaphragmatic weakness in neuromuscular disorders. Arch Phys Med Rehabil. 2001;82(1):123–8.

    Article  CAS  Google Scholar 

  65. Lechtzin N, Wiener CM, Shade DM, Clawson L, Diette GB. Spirometry in the supine position improves the detection of diaphragmatic weakness in patients with amyotrophic lateral sclerosis. Chest. 2002;121(2):436–42.

    Article  Google Scholar 

  66. Baumann F, Henderson RD, Morrison SC, et al. Use of respiratory function tests to predict survival in amyotrophic lateral sclerosis. Amyotroph Lateral Scler. 2010;11(1–2):194–202.

    Article  Google Scholar 

  67. Schmidt EP, Drachman DB, Wiener CM, Clawson L, Kimball R, Lechtzin N. Pulmonary predictors of survival in amyotrophic lateral sclerosis: use in clinical trial design. Muscle Nerve. 2006;33(1):127–32.

    Article  Google Scholar 

  68. Miller RG, Jackson CE, Kasarskis EJ, et al. Practice parameter update: the care of the patient with amyotrophic lateral sclerosis: drug, nutritional, and respiratory therapies (an evidence-based review): report of the quality standards Subcommittee of the American Academy of Neurology. Neurology. 2009;73(15):1218–26.

    Article  CAS  Google Scholar 

  69. Fugl-Meyer AR. Effects of respiratory muscle paralysis in tetraplegic and paraplegic patients. Scand J Rehabil Med. 1971;3(4):141–50.

    CAS  PubMed  Google Scholar 

  70. Fugl-Meyer AR, Grimby G. Respiration in tetraplegia and in hemiplegia: a review. Int Rehabil Med. 1984;6(4):186–90.

    Article  CAS  Google Scholar 

  71. Huldtgren AC, Fugl-Meyer AR, Jonasson E, Bake B. Ventilatory dysfunction and respiratory rehabilitation in post-traumatic quadriplegia. Eur J Respir Dis. 1980;61(6):347–56.

    CAS  PubMed  Google Scholar 

  72. Wade OL, Gilson JC. The effect of posture on diaphragmatic movement and vital capacity in normal subjects with a note on spirometry as an aid in determining radiological chest volumes. Thorax. 1951;6(2):103–26.

    Article  CAS  Google Scholar 

  73. Moreno F, Lyons HA. Effect of body posture on lung volumes. J Appl Physiol. 1961;16:27–9.

    Article  CAS  Google Scholar 

  74. Castile R, Mead J, Jackson A, Wohl ME, Stokes D. Effects of posture on flow-volume curve configuration in normal humans. J Appl Physiol Respir Environ Exerc Physiol. 1982;53(5):1175–83.

    CAS  PubMed  Google Scholar 

  75. Segizbaeva MO, Pogodin MA, Aleksandrova NP. Effects of body positions on respiratory muscle activation during maximal inspiratory maneuvers. Adv Exp Med Biol. 2013;756:355–63.

    Article  CAS  Google Scholar 

  76. Chang SC, Chang HI, Liu SY, Shiao GM, Perng RP. Effects of body position and age on membrane diffusing capacity and pulmonary capillary blood volume. Chest. 1992;102(1):139–42.

    Article  CAS  Google Scholar 

Download references


The authors wish to thank Prof. Ora Paltiel, a specialist in Internal Medicine, Hematology, and Oncology who also holds a doctorate in Epidemiology and Biostatistics, for her invaluable assistance in selecting the optimal tools for assessment of the quality of evidence and potential for bias of studies included in this systematic review.

The authors wish to thank Shifra Fraifeld, a medical center-based medical writer and editor, for her editorial contribution during manuscript preparation.

Author information

Authors and Affiliations



SK, E-LM, NA, AR contributed to the study concept and design. SK, E-LM, NA, AR, YZ contributed to data acquisition and analysis, and interpretation of the data. The primary literature search was conducted by SK and E-LM. SK and E-LM drafted the manuscript. SK, E-LM, NA, AR, YZ critically reviewed and revised the manuscript for intellectual content. All authors reviewed the final version of the manuscript prior to submission and all accept responsibility for the integrity of the research process and findings. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Ariel Rokach.

Ethics declarations

Ethics approval and consent to participate

Not applicable – systematic review.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Additional files

Additional file 1:

Table S1. Scoring for papers included in the systematic review based on the Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group of the National Heart, Lung and Blood Institute [3, 15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31, 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58]. (DOCX 63 kb)

Additional file 2:

Table S2. Statistically significant differences in pulmonary function between the various body positions [3, 17,18,19,20,21,22,23,24,25,26,27,28, 30, 31, 33, 34, 37,38,39,40,41, 43,44,45,46,47,48, 50,51,52,53,54, 56]. (DOCX 104 kb)

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Katz, S., Arish, N., Rokach, A. et al. The effect of body position on pulmonary function: a systematic review. BMC Pulm Med 18, 159 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: