Action of the diaphragm on the rib cage inferred from a force-balance analysis

Loring, S. H.; Mead, J.

doi:10.1152/jappl.1982.53.3.756

Cited by 118 publications

(89 citation statements)

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“…The diaphragm has a mechanism of expansion that involves not only the abdomen but also the lower thorax. 28 Therefore we assumed that the marker distances of the lower thorax were greater in the male subjects. In the sitting position, female subjects had significantly decreased upper thoracic movement, and there were significant negative relationships between upper thoracic movement and sex.…”

Section: Discussionmentioning

confidence: 99%

“…Possible causes are more predominant rib cage breathing and higher lung volumes. Loring and Mead 28 showed that the inspiratory action of the diaphragm on the rib cage was greatest at low lung volumes. Accordingly, during deep breathing, which involves higher lung volumes and relatively greater rib cage movement, expansion of the lower rib cage seems to be more difficult in the sitting position than in the supine position.…”

Section: Discussionmentioning

confidence: 99%

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Breathing Movements of the Chest and Abdominal Wall in Healthy Subjects

2012

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BACKGROUND: Physical assessment of breathing is an important component of physical therapy evaluations. However, there are no standardized reference values of breathing movements available for use in clinical practice. The purpose of this study was to determine the 3-dimensional distances of observational points on the thorax and abdomen during breathing in healthy subjects and to assess the effects of age, posture, and sex on breathing movements. METHODS: We studied the 3-dimensional breathing movement distances of the thorax and abdomen in 100 healthy subjects (50 males, 50 females). Breathing movements were measured with a 3-dimensional motion system during quiet and deep breathing with subjects in supine and sitting positions. Thirteen reflective markers were placed on the upper (the clavicles, 3rd ribs, and sternal angle) and lower thorax (the 8th ribs, 10th ribs, and xiphoid process) and the abdomen (upper abdomen and lateral abdomen). Range of movement in both breathing conditions was measured as the 3-dimensional distance at half respiratory cycle. Respiratory rates were calculated based on the breathing movements analyzed. One-way analysis of variance, t tests, and multiple regression were used for statistical analysis. RESULTS: The average marker distances for the thorax and abdomen during quiet breathing were less than one third of those during deep breathing. Upper thoracic movement was significantly decreased with age. There was less abdominal movement in females than in males, except during quiet breathing in the supine position. The distances between the thoracic markers were greater and those of the abdomen were less during quiet and deep breathing in the sitting position, compared with those in the supine position. CONCLUSIONS: We found that the observed breathing movements were related to the effects of age, sex, and posture. These findings are in agreement with those reported in previous studies. The results may be helpful in assessing breathing movement by physical examination.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Breathing Movements of the Chest and Abdominal Wall in Healthy Subjects

2012

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“…It is tempting to attribute this, at least in part, to the greater mechanical impairment of diaphragmatic function in these patients, compared to those with "isolated" chronic bronchitis or asthma. Nevertheless, both the lowering of pressure difference between peritoneum and pleura (∆Pdi) due to the flattening of the diaphragm [44], and the "intrinsic-PEEP" (auto-PEEP) phenomenon of emphysematous patients [45] should partially act against persistence of atelectasis during consciousness. The possible explanation(s) of this behaviour, as well as the importance of surgical transection of the transversus abdominis muscle (which many COPD patients contract during expiration) [46], are as yet unclear.…”

Section: Discussionmentioning

confidence: 99%

Upper abdominal surgery: does a lung function test exist to predict early severe postoperative respiratory complications?

Barisione¹,

Rovida²,

Gazzaniga³

et al. 1997

Eur Respir J

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We evaluated the capacity to predict severe respiratory complications (SRCs) following upper abdominal surgery (UAS) by using the results of a respiratory questionnaire and preoperative pulmonary function tests.Lung volumes, flows and transfer factor of the lung for carbon monoxide (TL,CO,sb) were assessed in 361 consecutive adult patients (248 males and 113 females). SRCs were diagnosed 24 h after UAS by clinical examination and chest radiography. Univariate and stepwise multiple logistic regression analyses were performed to estimate the odds ratio (OR) and 95% confidence interval (95% CI) of each single input variable, and to determine which indices best predicted outcome.These patients had a 1% mortality rate and 14% incidence of SRCs, with a male:female ratio of 0.86. The best predictors for SRCs by multiple analysis were: preoperative current hypersecretion of mucus (OR=133; p<0.0001); an increase in residual volume (RV) (OR=3.11; p=0.01); and, to a lesser extent, low percentage of predicted values both of forced expiratory volume in one second (FEV1 % pred) and TL,CO,sb. The algorithm thus obtained (logit θ) was extremely sensitive (84%), specific (99%), and accurate (95%) for preoperative prediction of SRCs.We have found that preoperative current hypersecretion of mucus and pulmonary hyperinflation, and to a lesser extent percentage predicted values both of forced expiratory volume in one second and transfer factor of the lung for carbon monoxide, have a significant predictive capacity for severe respiratory complications following upper abdominal surgery. Eur Respir J 1997; 10: 1301-1308 Since 1910, it has been well-known that patients undergoing upper abdominal surgery (UAS) generally develop a severe pulmonary restrictive pattern [1], and carry a high risk of postoperative respiratory complications [2][3][4]. The most important factors determining the degree of postoperative impairment of ventilation and gas exchange are the site of operation, the age, and clinical status of the patient [5]. Forced vital capacity (FVC) and peak flows are often reduced to half, and the functional residual capacity (FRC) to below 70% of the preoperative values [5]. These effects may not be restored even by the fifth postoperative day [5]. The reduced FVC and the reduction of FRC are mainly a consequence of an impaired diaphragmatic function [6]. Furthermore, the risk for postoperative respiratory complications decreases with the distance of the surgical incision from the diaphragm [7,8].Several studies have tried to determine the incidence of postoperative respiratory complications of UAS, and the estimates vary widely. The majority of investigations have focused on subclinical complications, i.e. radiographic evidence of atelectasis, with or without pleural fluid. With this broader definition of complication, the incidence of postoperative complications of UAS is approximately 25-75% [9,10].In this paper, we examine the relationship between preoperative respiratory symptoms and physiology, and postoperative r...

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“…Contraction of the diaphragm increases abdominal pressure and decreases pleural pressure. The increased abdominal pressure exerts an outward inspiratory force on the lower third of the rib cage, which is apposed to the diaphragm (34,35). The upward pull of the costal diaphragm also causes the lower rib cage to expand.…”

Section: Mechanical Actions In Situmentioning

confidence: 99%