Relative strengths of the chest wall muscles

1988 ◽  
Vol 65 (2) ◽  
pp. 852-862 ◽  
Author(s):  
M. B. Hershenson ◽  
Y. Kikuchi ◽  
S. H. Loring
Keyword(s):  
Muscle Strength ◽  
Chest Wall ◽  
Abdominal Muscle ◽  
Inspiratory Pressure ◽  
Abdominal Muscles ◽  
Maximal Inspiratory Pressure ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Closed Glottis

We hypothesized that during maximal respiratory efforts involving the simultaneous activation of two or more chest wall muscles (or muscle groups), differences in muscle strength require that the activity of the stronger muscle be submaximal to prevent changes in thoracoabdominal configuration. Furthermore we predicted that maximal respiratory pressures are limited by the strength of the weaker muscle involved. To test these hypotheses, we measured the pleural pressure, abdominal pressure (Pab), and transdiaphragmatic pressure (Pdi) generated during maximal inspiratory, open-glottis and closed-glottis expulsive, and combined inspiratory and expulsive maneuvers in four adults. We then determined the activation of the diaphragm and abdominal muscles during selected maximal respiratory maneuvers, using electromyography and phrenic nerve stimulation. In all subjects, the Pdi generated during maximal inspiratory efforts was significantly lower than the Pdi generated during open-glottis expulsive or combined efforts, suggesting that rib cage, not diaphragm, strength limits maximal inspiratory pressure. Similarly, at high lung volumes, the Pab generated during closed-glottis expulsive efforts was significantly greater than that generated during open-glottis efforts, suggesting that the latter pressure is limited by diaphragm, not abdominal muscle, strength. As predicted, diaphragm activation was submaximal during maximal inspiratory efforts, and abdominal muscle activation was submaximal during open-glottis expulsive efforts at midlung volume. Additionally, assisting the inspiratory muscles of the rib cage with negative body-surface pressure significantly increased maximal inspiratory pressure, whereas loading the rib cage muscles with rib cage compression decreased maximal inspiratory pressure. We conclude that activation of the chest wall muscles during static respiratory efforts is determined by the relative strengths and mechanical advantage of the muscles involved.

Partitioning of inspiratory pressure swings between diaphragm and intercostal/accessory muscles

1978 ◽  
Vol 44 (2) ◽  
pp. 200-208 ◽  
Author(s):  
P. T. Macklem ◽  
D. Gross ◽  
G. A. Grassino ◽  
C. Roussos
Keyword(s):  
Total Pressure ◽  
Pleural Pressure ◽  
Inspiratory Pressure ◽  
Abdominal Pressure ◽  
Abdominal Muscles ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Accessory Muscle ◽  
Inspiratory Muscles ◽  
Accessory Muscles

We tested the hypothesis that the inspiratory pressure swings across the rib-cage pathway are the sum of transdiaphragmatic pressure (Pdi) and the pressures developed by the intercostal/accessory muscles (Pic). If correct, Pic can only contribute to lowering pleural pressure (Ppl), to the extent that it lowers abdominal pressure (Pab). To test this we measured Pab and Ppl during during Mueller maneuvers in which deltaPab = 0. Because there was no outward displacement of the rib cage, Pic must have contributed to deltaPpl, as did Pdi. Under these conditions the total pressure developed by the inspiratory muscles across the rib-cage pathway was less than Pdi + Pic. Therefore, we rejected the hypothesis. A plot of Pab vs. Ppl during relaxation allows partitioning of the diaphragmatic and intercostal/accessory muscle contributions to inspiratory pressure swings. The analysis indicates that the diaphragm can act both as a fixator, preventing transmission of Ppl to the abdomen and as an agonist. When abdominal muscles remain relaxed it only assumes the latter role to the extent that Pab increases.

Effect of fatigue on maximal inspiratory pressure-flow capacity

1992 ◽  
Vol 73 (1) ◽  
pp. 36-43 ◽  
Author(s):  
F. D. McCool ◽  
M. B. Hershenson ◽  
G. E. Tzelepis ◽  
Y. Kikuchi ◽  
D. E. Leith
Keyword(s):  
Esophageal Pressure ◽  
Inspiratory Flow ◽  
Muscle Performance ◽  
Inspiratory Pressure ◽  
Maximal Inspiratory Pressure ◽  
Pressure Flow ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Flow Capacity ◽  
Inspiratory Muscles

The inspiratory muscles can be fatigued by repetitive contractions characterized by high force (inspiratory resistive loads) or high velocities of shortening (hyperpnea). The effects of fatigue induced by inspiratory resistive loaded breathing (pressure tasks) or by eucapnic hyperpnea (flow tasks) on maximal inspiratory pressure-flow capacity and rib cage and diaphragm strength were examined in five healthy adult subjects. Tasks consisted of sustaining an assigned breathing frequency, duty cycle, and either a “pressure-time product” of esophageal pressure (for the pressure tasks) or peak inspiratory flow rate (for the flow tasks). Esophageal pressure was measured during maximal inspiratory efforts against a closed glottis (Pesmax), maximal transdiaphragmatic pressure was measured during open-glottis expulsive maneuvers (Pdimax), and maximal inspiratory flow (VImax) was measured during maximal inspiratory efforts with no added external resistance before and after fatiguing pressure and flow tasks. The reduction in Pesmax) with pressure fatigue (-25 +/- 7%) was significantly greater than the change in Pesmax with flow fatigue (-8 +/- 8%, P less than 0.01). In contrast, the reductions in Pdimax (-11 +/- 8%) and VImax (-16 +/- 3%) with flow fatigue were greater than the changes in Pdimax (-0.6 +/- 4%, P less than 0.05) or VImax (-3 +/- 4%, P less than 0.05) with pressure fatigue. We conclude that respiratory muscle performance is dependent not only on the presence of fatigue but whether fatigue was induced by pressure tasks or flow tasks. The specific impairment of Pesmax and not of Pdimax or flow with pressure fatigue may reflect selective fatigue of the rib cage muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Chest wall distortion during resistive inspiratory loading

1985 ◽  
Vol 58 (5) ◽  
pp. 1646-1653 ◽  
Author(s):  
E. R. Ringel ◽  
S. H. Loring ◽  
J. Mead ◽  
R. H. Ingram
Keyword(s):  
Chest Wall ◽  
Wall Motion ◽  
Respiratory Muscles ◽  
Underlying Mechanism ◽  
Abdominal Muscles ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Circular Configuration ◽  
Chest Wall Motion ◽  
Resistive Loads

We studied six (1 naive and 5 experienced) subjects breathing with added inspiratory resistive loads while we recorded chest wall motion (anteroposterior rib cage, anteroposterior abdomen, and lateral rib cage) and tidal volumes. In the five experienced subjects, transdiaphragmatic and pleural pressures, and electromyographs of the sternocleidomastoid and abdominal muscles were also measured. Subjects inspired against the resistor spontaneously and then with specific instructions to reach a target pleural or transdiaphragmatic pressure or to maximize selected electromyographic activities. Depending on the instructions, a wide variety of patterns of inspiratory motion resulted. Although the forces leading to a more elliptical or circular configuration of the chest wall can be identified, it is difficult to analyze or predict the configurational results based on insertional and pressure-related contributions of a few individual respiratory muscles. Although overall chest wall respiratory motion cannot be readily inferred from the electromyographic and pressure data we recorded, it is clear that responses to loading can vary substantially within and between individuals. Undoubtedly, the underlying mechanism for the distortional changes with loading are complex and perhaps many are behavioral rather than automatic and/or compensatory.

Passive mechanics of upright human chest wall during immersion from hips to neck

1986 ◽  
Vol 60 (5) ◽  
pp. 1561-1570 ◽  
Author(s):  
M. B. Reid ◽  
S. H. Loring ◽  
R. B. Banzett ◽  
J. Mead
Keyword(s):  
Chest Wall ◽  
Esophageal Pressure ◽  
Vertical Surface ◽  
Repeated Measurements ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Gastric Pressure ◽  
Length Changes ◽  
Accessory Muscles

We have determined the mechanical effects of immersion to the neck on the passive chest wall of seated upright humans. Repeated measurements were made at relaxed end expiration on four subjects. Changes in relaxed chest wall configuration were measured using magnetometers. Gastric and esophageal pressures were measured with balloon-tipped catheters in three subjects; from these, transdiaphragmatic pressure was calculated. Transabdominal pressure was estimated using a fluid-filled, open-tipped catheter referenced to the abdomen's exterior vertical surface. We found that immersion progressively reduced mean transabdominal pressure to near zero and that the relaxed abdominal wall was moved inward 3–4 cm. The viscera were displaced upward into the thorax, gastric pressure increased by 20 cmH2O, and transdiaphragmatic pressure decreased by 10–15 cmH2O. This lengthened the diaphragm, elevating the diaphragmatic dome 3–4 cm. Esophageal pressure became progressively more positive throughout immersion, increasing by 8 cmH2O. The relaxed rib cage was elevated and expanded by raising water from hips to lower sternum; this passively shortened the inspiratory intercostals and the accessory muscles of inspiration. Deeper immersion distorted the thorax markedly: the upper rib cage was forced inward while lower rib cage shape was not systematically altered and the rib cage remained elevated. Such distortion may have passively lengthened or shortened the inspiratory muscles of the rib cage, depending on their location. We conclude that the nonuniform forcing produced by immersion provides unique insights into the mechanical characteristics of the abdomen and rib cage, that immersion-induced length changes differ among the inspiratory muscles according to their locations and the depth of immersion, and that such length changes may have implications for patients with inspiratory muscle deficits.

Respiratory response to abdominal and rib cage muscle paralysis in dogs

1993 ◽  
Vol 74 (5) ◽  
pp. 2309-2317 ◽  
Author(s):  
J. F. Brichant ◽  
M. Gorini ◽  
A. De Troyer
Keyword(s):  
Tidal Volume ◽  
Abdominal Cavity ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Respiratory Response ◽  
Muscle Paralysis ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Inspiratory Muscles ◽  
Arterial Blood

To assess the respiratory response to abdominal and rib cage muscle paralysis, we measured tidal volume, esophageal and gastric pressures, arterial blood gases, and the electromyogram (EMG) of the diaphragm during progressive epidural anesthesia (lidocaine 2%) in 35 supine anesthetized dogs. The EMG activity of the diaphragm was measured with fine-wire electrodes; the abdominal cavity was thus left intact. Paralysis of the abdominal muscles alone did not produce any alterations. In contrast, when all rib cage muscles were also paralyzed, there were substantial increases in the peak height and the rate of rise of diaphragmatic EMG activity that were associated with a decrease in tidal volume and an increase in arterial PCO2 (PaCO2); swings in transdiaphragmatic pressure, however, were unchanged. The increased diaphragmatic activation due to rib cage muscle paralysis persisted after bilateral cervical vagotomy and was well explained by the increased PaCO2. These observations indicate that in the dog 1) the rib cage muscles contribute significantly to tidal volume, and their paralysis causes, through the increased hypercapnic drive, a compensatory increase in diaphragmatic activation; and 2) the rib cage inspiratory muscles enhance the diaphragm's ability to generate pressure during breathing.

Rib cage mechanics during quiet breathing and exercise in humans

1997 ◽  
Vol 83 (4) ◽  
pp. 1242-1255 ◽  
Author(s):  
C. M. Kenyon ◽  
S. J. Cala ◽  
S. Yan ◽  
A. Aliverti ◽  
G. Scano ◽  
...  
Keyword(s):  
Chest Wall ◽  
Respiratory Muscles ◽  
Relaxation Curve ◽  
Abdominal Pressure ◽  
Abdominal Muscles ◽  
Quiet Breathing ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Ergometer Exercise ◽  
Exercise In Humans

Kenyon, C. M., S. J. Cala, S. Yan, A. Aliverti, G. Scano, R. Duranti, A. Pedotti, and Peter T. Macklem. Rib cage mechanics during quiet breathing and exercise in humans. J. Appl. Physiol. 83(4): 1242–1255, 1997.—During exercise, large pleural, abdominal, and transdiaphragmatic pressure swings might produce substantial rib cage (RC) distortions. We used a three-compartment chest wall model ( J. Appl. Physiol. 72: 1338–1347, 1992) to measure distortions of lung- and diaphragm-apposed RC compartments (RCp and RCa) along with pleural and abdominal pressures in five normal men. RCp and RCa volumes were calculated from three-dimensional locations of 86 markers on the chest wall, and the undistorted (relaxation) RC configuration was measured. Compliances of RCp and RCa measured during phrenic stimulation against a closed airway were 20 and 0%, respectively, of their values during relaxation. There was marked RC distortion. Thus nonuniform distribution of pressures distorts the RC and markedly stiffens it. However, during steady-state ergometer exercise at 0, 30, 50, and 70% of maximum workload, RC distortions were small because of a coordinated action of respiratory muscles, so that net pressures acting on RCp and RCa were nearly the same throughout the respiratory cycle. This maximizes RC compliance and minimizes the work of RC displacement. During quiet breathing, plots of RCa volume vs. abdominal pressure were to the right of the relaxation curve, indicating an expiratory action on RCa. We attribute this to passive stretching of abdominal muscles, which more than counterbalances the insertional component of transdiaphragmatic pressure.

Triangularis sterni muscle use in supine humans

1987 ◽  
Vol 62 (3) ◽  
pp. 919-925 ◽  
Author(s):  
A. De Troyer ◽  
V. Ninane ◽  
J. J. Gilmartin ◽  
C. Lemerre ◽  
M. Estenne
Keyword(s):  
Normal Subjects ◽  
Abdominal Muscle ◽  
Abdominal Muscles ◽  
Neural Activation ◽  
Trained Subjects ◽  
Rib Cage ◽  
Residual Capacity ◽  
External Oblique ◽  
Head Flexion ◽  
Static Head

The electrical activity of the triangularis sterni (transversus thoracis) muscle was studied in supine humans during resting breathing and a variety of respiratory and nonrespiratory maneuvers known to bring the abdominal muscles into action. Twelve normal subjects, of whom seven were uninformed and untrained, were investigated. The electromyogram of the triangularis sterni was recorded using a concentric needle electrode, and it was compared with the electromyograms of the abdominal (external oblique and rectus abdominis) muscles. The triangularis sterni was usually silent during resting breathing. In contrast, the muscle was invariably activated during expiration from functional residual capacity, expulsive maneuvers, “belly-in” isovolume maneuvers, static head flexion and trunk rotation, and spontaneous events such as speech, coughing, and laughter. When three trained subjects expired voluntarily with considerable recruitment of the triangularis sterni and no abdominal muscle activity, rib cage volume decreased and abdominal volume increased. These results indicate that unlike in the dog, spontaneous quiet expiration in supine humans is essentially a passive process; the human triangularis sterni, however, is a primary muscle of expiration; and its neural activation is largely coupled with that of the abdominals. The triangularis sterni probably contributes to the deflation of the rib cage during active expiration.

scholarly journals Inspiratory muscle strength in subjects with tetraplegia: viability of evaluation through the measurement of maximal inspiratory pressure

2014 ◽  
Vol 27 (3) ◽  
pp. 371-377
Author(s):  
Marlene Aparecida Moreno ◽  
Juliana Viana Paris ◽  
Raphael do Nascimento Pereira ◽  
Antonio Roberto Zamunér ◽  
Tais Mendes de Camargo ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Study ◽  
Inspiratory Muscle ◽  
Inspiratory Pressure ◽  
Maximal Inspiratory Pressure ◽  
Cross Sectional ◽  
Pressure Meter ◽  
Predicted Values ◽  
Inspiratory Muscle Strength ◽  
Sniff Nasal Inspiratory Pressure

Objective To analyze the values of maximal inspiratory pressure (MIP) and sniff nasal inspiratory pressure (SNIP) and to verify the existence of concordance between the two evaluation methodologies, in subjects with tetraplegia. Materials and methods Cross-sectional study with 17 tetraplegic men, aged 30.42 ± 7.67 years, who underwent MIP and SNIP evaluation using a respiratory pressure meter. Results The MIP and SNIP values obtained showed no difference when compared to each other (88.42 ± 29.39 vs. 86.68 ± 25.40 cmH2O, respectively). They were, however, significantly lower compared to the predicted values (MIP = 128.92 ± 7.18; SNIP = 114.11 ± 3.19 cmH2O), with the MIP values presenting correlation (r2 = 0.94; p < 0.0001) and concordance with those of the SNIP. Conclusions Both the MIP and SNIP values obtained were lower than the predicted values, indicating a reduction in inspiratory muscle strength (IMS). Both techniques showed correlation and concordance, suggesting that MIP can be used as a noninvasive method for IMS evaluation in this population.

Human respiratory muscle actions and control during exercise

1997 ◽  
Vol 83 (4) ◽  
pp. 1256-1269 ◽  
Author(s):  
A. Aliverti ◽  
S. J. Cala ◽  
R. Duranti ◽  
G. Ferrigno ◽  
C. M. Kenyon ◽  
...  
Keyword(s):  
Lung Volume ◽  
Respiratory Muscle ◽  
Abdominal Muscle ◽  
Abdominal Pressure ◽  
Abdominal Muscles ◽  
Quiet Breathing ◽  
Rib Cage ◽  
Velocity Of Shortening ◽  
And Control ◽  
Muscle Actions

Aliverti, A., S. J. Cala, R. Duranti, G. Ferrigno, C. M. Kenyon, A. Pedotti, G. Scano, P. Sliwinski, Peter T. Macklem, and S. Yan. Human respiratory muscle actions and control during exercise. J. Appl. Physiol. 83(4): 1256–1269, 1997.—We measured pressures and power of diaphragm, rib cage, and abdominal muscles during quiet breathing (QB) and exercise at 0, 30, 50, and 70% maximum workload (W˙max) in five men. By three-dimensional tracking of 86 chest wall markers, we calculated the volumes of lung- and diaphragm-apposed rib cage compartments (Vrc,p and Vrc,a, respectively) and the abdomen (Vab). End-inspiratory lung volume increased with percentage of W˙max as a result of an increase in Vrc,p and Vrc,a. End-expiratory lung volume decreased as a result of a decrease in Vab. ΔVrc,a/ΔVab was constant and independent ofW˙max. Thus we used ΔVab/time as an index of diaphragm velocity of shortening. From QB to 70%W˙max, diaphragmatic pressure (Pdi) increased ∼2-fold, diaphragm velocity of shortening 6.5-fold, and diaphragm workload 13-fold. Abdominal muscle pressure was ∼0 during QB but was equal to and 180° out of phase with rib cage muscle pressure at all percent W˙max. Rib cage muscle pressure and abdominal muscle pressure were greater than Pdi, but the ratios of these pressures were constant. There was a gradual inspiratory relaxation of abdominal muscles, causing abdominal pressure to fall, which minimized Pdi and decreased the expiratory action of the abdominal muscles on Vrc,a gradually, minimizing rib cage distortions. We conclude that from QB to 0% W˙max there is a switch in respiratory muscle control, with immediate recruitment of rib cage and abdominal muscles. Thereafter, a simple mechanism that increases drive equally to all three muscle groups, with drive to abdominal and rib cage muscles 180° out of phase, allows the diaphragm to contract quasi-isotonically and act as a flow generator, while rib cage and abdominal muscles develop the pressures to displace the rib cage and abdomen, respectively. This acts to equalize the pressures acting on both rib cage compartments, minimizing rib cage distortion .

Effects of separate rib cage and abdominal restriction on exercise performance in normal humans

1985 ◽  
Vol 58 (6) ◽  
pp. 2020-2026 ◽  
Author(s):  
S. N. Hussain ◽  
B. Rabinovitch ◽  
P. T. Macklem ◽  
R. L. Pardy
Keyword(s):  
Minute Ventilation ◽  
Normal Subjects ◽  
Cycle Ergometer ◽  
Abdominal Muscle ◽  
Work Rate ◽  
Abdominal Pressure ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Constant Work Rate ◽  
And Control

We assessed the effects of selective restriction of movements of the rib cage (Res,rc) and abdomen (Res,ab) on ventilatory pattern, transdiaphragmatic pressure (Pdi), and electrical activity of the diaphragm (Edi) in five normal subjects exercising at a constant work rate (80% of maximum power output) on a cycle ergometer till exhaustion. Restriction of movements was achieved by an inelastic corset applied tightly around the rib cage or abdomen. Edi was recorded by an esophageal electrode, rectified, and then integrated, and peak values during inspiration were measured. Each subject exercised at the same work rate on 3 days: with Res,rc, with Res,ab, and without restriction (control). Res,rc but not Res,ab reduced exercise time (tlim). Up to tlim, minute ventilation (VE) was similar in all three conditions. At any level of VE, however, Res,rc decreased tidal volume and inspiratory and expiratory time, whereas Res,ab had no effect on the pattern of breathing. Res,ab was associated with higher inspiratory Pdi swings at any level of VE, whereas peak Edi was similar to control. Inspiratory Pdi swings were the same with Res,rc as control, but the peak Edi for a given Pdi was greater with Res,rc (P less than 0.05). During Res,rc the abdominal pressure swings in expiration were greater than with Res,ab and control. We conclude that Res,rc altered the pattern of breathing in normal subjects in high-intensity exercise, decreased diaphragmatic contractility, increased abdominal muscle recruitment in expiration, and reduced tlim. On the other hand, Res,ab had no effect on breathing pattern or tlim but was associated with increased diaphragmatic contractility.

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