Effects of pulse lung inflation on chest wall expiratory motor activity

2007 ◽  
Vol 102 (1) ◽  
pp. 485-491 ◽  
Author(s):  
Jaroslaw R. Romaniuk ◽  
Thomas E. Dick ◽  
Krzysztof E. Kowalski ◽  
Anthony F. DiMarco
Keyword(s):  
Motor Activity ◽  
Muscle Activity ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Phase Duration ◽  
Lung Inflation ◽  
Expiratory Phase ◽  
Expiratory Muscle ◽  
Bilateral Vagotomy

The effects of pulse lung inflation (LI) on expiratory muscle activity and phase duration (Te) were determined in anesthetized, spontaneously breathing dogs ( n = 20). A volume syringe was used to inflate the lungs at various times during the expiratory phase. The magnitude of lung volume was assessed by the corresponding change in airway pressure (Paw; range 2–20 cmH2O). Electromyographic (EMG) activities were recorded from both thoracic and abdominal muscles. Parasternal muscle EMG was used to record inspiratory activity. Expiratory activity was assessed from the triangularis sterni (TS), internal intercostal (IIC), and transversus abdominis (TA) muscles. Lung inflations <7 cmH2O consistently inhibited TS activity but had variable effects on TA and IIC activity and expiratory duration. Lung inflations resulting in Paw values >7 cmH2O, however, inhibited expiratory EMG activity of each of the expiratory muscles and lengthened Te in all animals. The responses of expiratory EMG and Te were directly related to the magnitude of the lung inflation. The inhibition of expiratory motor activity was independent of the timing of pulse lung inflation during the expiratory phase. The inhibitory effects of lung inflation were eliminated by bilateral vagotomy and could be reproduced by electrical stimulation of the vagus nerve. We conclude that pulse lung inflation resulting in Paw between 7 and 20 cmH2O produces a vagally mediated inhibition of expiratory muscle activity that is directly related to the magnitude of the inflation. Lower inflation pressures produce variable effects that are muscle specific.

Expiratory muscle activity in the awake and sleeping human during lung inflation and hypercapnia

1992 ◽  
Vol 72 (3) ◽  
pp. 881-887 ◽  
Author(s):  
Y. Wakai ◽  
M. M. Welsh ◽  
A. M. Leevers ◽  
J. D. Road
Keyword(s):  
Lung Volume ◽  
Muscle Activity ◽  
Ventilatory Threshold ◽  
Minute Ventilation ◽  
Abdominal Muscle ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Lung Inflation ◽  
Expiratory Muscle ◽  
Intramuscular Electrodes

Expiratory muscle activity has been shown to occur in awake humans during lung inflation; however, whether this activity is dependent on consciousness is unclear. Therefore we measured abdominal muscle electromyograms (intramuscular electrodes) in 13 subjects studied in the supine position during wakefulness and non-rapid-eye-movement sleep. Lung inflation was produced by nasal continuous positive airway pressure (CPAP). CPAP at 10–15 cmH2O produced phasic expiratory activity in two subjects during wakefulness but produced no activity in any subject during sleep. During sleep, CPAP to 15 cmH2O increased lung volume by 1,260 +/- 215 (SE) ml, but there was no change in minute ventilation. The ventilatory threshold at which phasic abdominal muscle activity was first recorded during hypercapnia was 10.3 +/- 1.1 l/min while awake and 13.8 +/- 1 l/min while asleep (P less than 0.05). Higher lung volumes reduced the threshold for abdominal muscle recruitment during hypercapnia. We conclude that lung inflation alone over the range that we studied does not alter ventilation or produce recruitment of the abdominal muscles in sleeping humans. The internal oblique and transversus abdominis are activated at a lower ventilatory threshold during hypercapnia, and this activation is influenced by state and lung volume.

Posture effects on timing of abdominal muscle activity during stimulated ventilation

1999 ◽  
Vol 86 (6) ◽  
pp. 1994-2000 ◽  
Author(s):  
Tadashi Abe ◽  
Takumi Yamada ◽  
Tomoyuki Tomita ◽  
Paul A. Easton
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Moving Average ◽  
Abdominal Muscle ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
External Oblique ◽  
End Tidal ◽  
Internal Oblique

In humans during stimulated ventilation, substantial abdominal muscle activity extends into the following inspiration as postexpiratory expiratory activity (PEEA) and commences again during late inspiration as preexpiratory expiratory activity (PREA). We hypothesized that the timing of PEEA and PREA would be changed systematically by posture. Fine-wire electrodes were inserted into the rectus abdominis, external oblique, internal oblique, and transversus abdominis in nine awake subjects. Airflow, end-tidal CO2, and moving average electromyogram (EMG) signals were recorded during resting and CO2-stimulated ventilation in both supine and standing postures. Phasic expiratory EMG activity (tidal EMG) of the four abdominal muscles at any level of CO2 stimulation was greater while standing. Abdominal muscle activities during inspiration, PEEA, and PREA, were observed with CO2stimulation, both supine and standing. Change in posture had a significant effect on intrabreath timing of expiratory muscle activation at any level of CO2stimulation. The transversus abdominis showed a significant increase in PEEA and a significant decrease in PREA while subjects were standing; similar changes were seen in the internal oblique. We conclude that changes in posture are associated with significant changes in phasic expiratory activity of the four abdominal muscles, with systematic changes in the timing of abdominal muscle activity during early and late inspiration.

Differential respiratory activity of four abdominal muscles in humans

1996 ◽  
Vol 80 (4) ◽  
pp. 1379-1389 ◽  
Author(s):  
T. Abe ◽  
N. Kusuhara ◽  
N. Yoshimura ◽  
T. Tomita ◽  
P. A. Easton
Keyword(s):  
Moving Average ◽  
Standing Position ◽  
Transversus Abdominis ◽  
Ultra Sound ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Expiratory Muscle ◽  
Expiratory Muscles ◽  
Expiratory Flow ◽  
End Tidal

Together the abdominal muscles contribute significantly to ventilation under some conditions, but there is little information regarding individual recruitment and timing of activation of the four abdominal muscles in humans. Fine-wire electrodes were inserted under direct vision guided by high-resolution ultra-sound into the rectus abdominis (Rectus), external oblique (Extern), internal oblique (Intern), and transversus abdominis (Transv) in nine awake healthy subjects. Airflow, end-tidal CO2, and moving-average EMG signals were recorded during 1) supine resting and CO2-stimulated ventilation and 2) resting ventilation in the standing position. During resting supine breathing, Transv showed significant phasic EMG activity during expiration. As posture changed from supine to standing, phasic activity during resting ventilation was greatest in Transv, with lesser activity in Intern and Extern, while Rectus remained inactive. As CO2 began to increase, Transv was activated first, followed by Intern, the Extern, and finally Rectus. With moderate CO2 stimulation, Transv and Intern were more active than was Extern and Rectus remained least active. EMG activities in the expiratory muscles after cessation of expiratory flow (postexpiratory expiratory activity) and in expiratory muscle activity preceding expiratory flow were observed consistently during supine stimulated ventilation and standing resting ventilation. These activities before and after expiratory airflow were prominent with stimulated ventilation during a substantial portion of inspiration, suggesting dual control of inspiratory pump action by both inspiratory and expiratory muscles, which provide acceleration and braking actions, respectively. These results suggest that in awake humans 1) during resting ventilation, expiration is an active process; 2) abdominal muscles are activated differentially; 3) Transv is the most active, Intern and Extern are intermediate, and Rectus is the least active expiratory muscle; and 4) during stimulated ventilation, inspiratory and expiratory muscles contribute dually to inspiratory pump action.

Vagal contributions to respiratory muscle activity during eupnea in the awake dog

1992 ◽  
Vol 72 (4) ◽  
pp. 1355-1361 ◽  
Author(s):  
D. M. Ainsworth ◽  
C. A. Smith ◽  
B. D. Johnson ◽  
S. W. Eicker ◽  
K. S. Henderson ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Muscle Activity ◽  
Respiratory Muscle ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Expiratory Muscle ◽  
Vagal Blockade ◽  
Inspiratory Activity ◽  
Vagal Cooling ◽  
Respiratory Muscle Activity

We examined the effects of reversible vagal cooling on respiratory muscle activities in awake chronically instrumented tracheotomized dogs. We specifically analyzed electromyographic (EMG) activity and its ventilatory correlates, end-expiratory lung volume (EELV) and diaphragmatic resting length via sonomicrometry. Elimination of phasic and tonic mechanoreceptor activity by vagal cooling doubled the EMG activity of the costal, crural, and parasternal muscles, with activation occurring sooner relative to the onset of inspiratory flow. Diaphragmatic postinspiration inspiratory activity in the intact dog coincided with a brief mechanical shortening of the diaphragm during early expiration; vagal blockade removed both the electrical activity and the mechanical shortening. Vagal blockade also doubled the EMG activity of a rib cage expiratory muscle, the triangularis sterni, but reduced that of an abdominal expiratory muscle, the transversus abdominis. Within-breath electrical activity of both muscles occurred sooner relative to the onset of expiratory flow during vagal blockade. Vagal cooling was also associated with a 12% increase in EELV and a 5% decrease in end-expiratory resting length of the diaphragm. We conclude that vagal input significantly modulates inspiratory and expiratory muscle activities, which help regulate EELV efficiently and optimize diaphragmatic length during eupneic breathing in the awake dog.

scholarly journals Surface electromyography comparison of the abdominal hypopressive gymnastics against the prone bridge exercise

2019 ◽  
Vol 12 (3) ◽  
pp. 243-246
Author(s):  
Gonzalo Alfonso Quiroz Sandoval ◽  
Nathalie Tabilo ◽  
Cristóbal Bahamondes ◽  
Pilar Bralic
Keyword(s):  
Abdominal Wall ◽  
Muscle Activity ◽  
Surface Electromyography ◽  
Healthy Subjects ◽  
Muscle Activation ◽  
Transversus Abdominis ◽  
Abdominal Pressure ◽  
Abdominal Muscles ◽  
External Oblique ◽  
Internal Oblique

Objectives: Abdominal hypopressive gymnastics (AHG) is a little-researched method designed to train the muscles of the abdominal wall and pelvic floor under low stress. This study’s objective is to compare levels of muscle activation in AHG against prone bridge by surface electromyography (sEMG) of the abdominal wall muscles. Methods: Twenty healthy subjects were enrolled to measure the muscle activity of the rectus abdominis (RA), transversus abdominis/internal oblique (Tra/IO), and external oblique (EO) during three exercises: prone bridge (PB), orthostatic hypopressive (OH), and hypopressive bridge (HB). Root mean square values normalized to the PB (%PB) as a baseline were used to compare the PB against OH and HB. Results: The median PB ratio (%PB) for the Tra/IO showed –10.31% and +59.7% activation during OH and the HB, respectively, whereas the RA showed –77.8% and +19.3% and the EO –39.8% and +9.8%. Significant differences were found for all muscles except the Tra/IO during the OH. Conclusion: This study’s results suggest that hypopressive exercises facilitate the activation of the Tra/IO similar to bridge exercises while simultaneously reducing RA and EO activity. This suggests that hypopressive training is a valid alternative for activating the abdominal muscles, isolating the Tra/IO at low intra-abdominal pressure.

Respiratory muscle responses elicited by dorsal periaqueductal gray stimulation in rats

2005 ◽  
Vol 289 (5) ◽  
pp. R1338-R1347 ◽  
Author(s):  
Weirong Zhang ◽  
Linda F. Hayward ◽  
Paul W. Davenport
Keyword(s):  
Gray Matter ◽  
Muscle Activity ◽  
Respiratory Muscle ◽  
Stimulus Frequency ◽  
Periaqueductal Gray ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Respiratory Response ◽  
Defense Behavior ◽  
Periaqueductal Gray Matter

The periaqueductal gray matter is an essential neural substrate for central integration of defense behavior and accompanied autonomic responses. The dorsal half of the periaqueductal gray matter (dPAG) is also involved in mediating emotional responses of anxiety and fear, psychological states that often are associated with changes in ventilation. However, information regarding respiratory modulation elicited from this structure is limited. The present study was undertaken to investigate the relationship between stimulus frequency and magnitude on ventilatory pattern and respiratory muscle activity in urethane-anesthetized, spontaneously breathing rats. Electrical stimulation in the dPAG-recruited abdominal muscle activity increased ventilation and increased respiratory frequency by significantly shortening both inspiratory time and expiratory time. Ventilation increased within the first breath after the onset of stimulation, and the respiratory response increased with increasing stimulus frequency and magnitude. dPAG stimulation also increased baseline EMG activity in the diaphragm and recruited baseline external abdominal oblique EMG activity, normally quiescent during eupneic breathing. Significant changes in cardiorespiratory function were only evoked by stimulus intensities >10 μA and when stimulus frequencies were >10 Hz. Respiratory activity of both the diaphragm and abdominal muscles remained elevated for a minimum of 60 s after cessation of stimulation. These results demonstrate that there is a short-latency respiratory response elicited from the dPAG stimulation, which includes both inspiratory and expiratory muscles. The changes in respiratory timing suggest rapid onset and sustained poststimulus dPAG modulation of the brain stem respiratory network that includes expiratory muscle recruitment.

Variations in respiratory muscle activity during echolocation when stationary in three species of bat (Microchiroptera: Vespertilionidae)

2001 ◽  
Vol 204 (24) ◽  
pp. 4185-4197
Author(s):  
Winston C. Lancaster ◽  
J. R. Speakman
Keyword(s):  
Muscle Activity ◽  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Pteronotus Parnellii ◽  
Economic Production ◽  
Morphological Adaptations ◽  
The Family ◽  
Respiratory Muscle Activity

SUMMARY Echolocating bats use respiratory muscles to power the production of biosonar vocalisations. The physical characteristics of these calls vary among species of bat, and variations also exist in the timing and patterns of respiratory muscle recruitment during echolocation. We recorded electromyograms from the respiratory muscles of three species of bat (Family Vespertilionidae) while the animals vocalised from stationary positions. Activity was recorded consistently from the lateral abdominal muscles (internal abdominal oblique and transversus abdominis) from all calling bats, but we found much variation within and among species. Bats in the family Vespertilionidae devoted longer periods of expiratory muscle activity to each call than did the mormoopid bat Pteronotus parnellii. These differences correlate negatively with the duration of calls. We suggest that morphological adaptations in some bats may facilitate the economic production of echolocation calls at rest.

Changes in muscle activity and perceived exertion during exercises performed on a swiss ball

2006 ◽  
Vol 31 (4) ◽  
pp. 376-383 ◽  
Author(s):  
Paul Marshall ◽  
Bernadette Murphy
Keyword(s):  
Muscle Activity ◽  
Perceived Exertion ◽  
Oblique Muscle ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Unstable Surface ◽  
Primary Base ◽  
Base Of Support ◽  
Hip Flexor ◽  
Swiss Ball

The objective of this study was to determine differences in electromyographic (EMG) activity of prime mover and abdominal muscles while performing squats, push ups, and double leg lowering with a swiss ball. Twelve healthy subjects performed the movements. There was no difference between the surface conditions for muscle activity during the squat exercise; however, individuals had lower perceived exertion for the swiss ball squat. Activity of the triceps and abdominals was highest performing push ups on the swiss ball, whereas the activity of rectus abdominus (RA) only increased during double leg lowering on the swiss ball. Perceived exertion was highest for the push up and leg-lowering exercise performed on the swiss ball. Increased RA activity during double leg lowering can be attributed to its role as a hip flexor, whereas the lack of a rotation aspect to the task prevented increased oblique muscle activity. The swiss ball appears to only increase muscle activity during exercises where the unstable surface is the primary base of support.

Reproducibility and responsiveness of a noninvasive EMG technique of the respiratory muscles in COPD patients and in healthy subjects

2004 ◽  
Vol 96 (5) ◽  
pp. 1723-1729 ◽  
Author(s):  
Marieke L. Duiverman ◽  
Leo A. van Eykern ◽  
Peter W. Vennik ◽  
Gerard H. Koëter ◽  
Eric J. W. Maarsingh ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Healthy Subjects ◽  
Respiratory Muscles ◽  
Emg Activity ◽  
Chronic Obstructive ◽  
Abdominal Muscles ◽  
Breathing Patterns ◽  
Obstructive Pulmonary Disease ◽  
Intercostal Muscles ◽  
Copd Patients

In the present study, we assessed the reproducibility and responsiveness of transcutaneous electromyography (EMG) of the respiratory muscles in patients with chronic obstructive pulmonary disease (COPD) and healthy subjects during breathing against an inspiratory load. In seven healthy subjects and seven COPD patients, EMG signals of the frontal and dorsal diaphragm, intercostal muscles, abdominal muscles, and scalene muscles were derived on 2 different days, both during breathing at rest and during breathing through an inspiratory threshold device of 7, 14, and 21 cmH2O. For analysis, we used the logarithm of the ratio of the inspiratory activity during the subsequent loads and the activity at baseline [log EMG activity ratio (EMGAR)]. Reproducibility of the EMG was assessed by comparing the log EMGAR values measured at test days 1 and 2 in both groups. Responsiveness (sensitivity to change) of the EMG was assessed by comparing the log EMGAR values of the COPD patients to those of the healthy subjects at each load. During days 1 and 2, log EMGAR values of the diaphragm and the intercostal muscles correlated significantly. For the scalene muscles, significant correlations were found for the COPD patients. Although inspiratory muscle activity increased significantly during the subsequent loads in all participants, the COPD patients displayed a significantly greater increase in intercostal and left scalene muscle activity compared with the healthy subjects. In conclusion, the present study showed that the EMG technique is a reproducible and sensitive technique to assess breathing patterns in COPD patients and healthy subjects.

Mechanical response to hyperinflation of the two abdominal muscle layers

1989 ◽  
Vol 66 (5) ◽  
pp. 2189-2195 ◽  
Author(s):  
A. M. Leevers ◽  
J. D. Road
Keyword(s):  
Functional Residual Capacity ◽  
Muscle Length ◽  
Abdominal Muscle ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Lung Inflation ◽  
Residual Capacity ◽  
Length Changes ◽  
External Oblique ◽  
Internal Oblique

Abdominal muscle length changes and activity were directly examined in vivo with the use of the techniques of sonomicrometry and electromyography, respectively, in nine supine anesthetized dogs. Expiratory threshold loading was utilized to stimulate recruitment of the abdominal muscles, and lung inflations produced the passive relationships. The internal layer, consisting of the internal oblique and transversus abdominis, shortened more in expiration than the external layer, consisting of the external oblique and rectus abdominis. The internal oblique shortened to approximately 83% of its length at functional residual capacity vs. 98% for the external oblique (P less than 0.05). The results obtained during passive lung inflation indicate these internal muscles are also more influenced by changes in lung volume. The internal oblique lengthened to 115% of its length at functional residual capacity vs. 103% for external oblique at total lung capacity (P less than 0.05). The results suggest that anatomic division of the abdominal muscles into external and internal layers corresponds to functional differences in terms of both passive lengthening and active shortening during ventilation and that these differences imply variable functions of the two layers.

Sign in / Sign up

Export Citation Format

Share Document