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.

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.

Abdominal muscle activity during hypercapnia in awake dogs

1994 ◽  
Vol 77 (3) ◽  
pp. 1393-1398 ◽  
Author(s):  
A. M. Leevers ◽  
J. D. Road
Keyword(s):  
Tidal Volume ◽  
Muscle Layer ◽  
Abdominal Muscle ◽  
Rectus Abdominis ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Co2 Rebreathing ◽  
External Oblique ◽  
Internal Oblique

We previously found the internal abdominal muscle layer to be preferentially recruited during expiratory threshold loading in anesthetized and awake dogs. Expiratory threshold loading increases end-expiratory lung volume and hence can activate reflex pathways such as tonic vagal reflexes, which could influence abdominal muscle recruitment. Our objectives in the present study were to determine the effects of hypercapnia on abdominal muscle activation and the pattern of recruitment in awake dogs. Five tracheotomized dogs were chronically implanted with sonomicrometer transducers and fine-wire electromyogram (EMG) electrodes in each of the four abdominal muscles: transversus abdominis, internal oblique, external oblique, and rectus abdominis. Muscle length changes and EMG activity were studied in the awake dog at rest and during CO2 rebreathing. CO2 rebreathing produced a tripling of tidal volume and activation of the abdominal muscles. Despite the increase in tidal volume, there was no significant change in abdominal muscle end-inspiratory length. Both tonic and phasic expiratory shortening were greater in the internal muscle layer (transversus abdominis and internal oblique) than in the external muscle layer (external oblique and rectus abdominis). We conclude that the internal abdominal muscles are preferentially recruited by hypercapnia and vagal reflexes probably do not contribute to this differential recruitment but that segmental reflexes may be involved. The mechanical consequences of this recruitment are discussed.

Abdominal muscle activation by respiratory stimuli in conscious dogs

1993 ◽  
Vol 74 (1) ◽  
pp. 16-23 ◽  
Author(s):  
F. Yasuma ◽  
R. J. Kimoff ◽  
L. F. Kozar ◽  
S. J. England ◽  
T. D. Bradley ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Respiratory Muscles ◽  
Abdominal Muscle ◽  
Minute Volume ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Vagus Nerves ◽  
Peripheral Chemoreceptor ◽  
External Oblique

The responses of the diaphragm, external oblique, and transversus abdominis muscles to hyperoxic hypercapnia and isocapnic hypoxia were studied in four awake dogs to test the hypothesis that central and peripheral chemoreceptor inputs result in different patterns of respiratory muscle activation. The dogs were trained to lie quietly in place, and electromyographic (EMG) discharges of the diaphragm (EMGdi), external oblique (EMGeo), and transversus abdominis (EMGta) were recorded from chronically implanted electrodes. Both hypercapnia and hypoxia recruited EMGeo and EMGta activity, but at comparable levels of minute volume of ventilation the EMG activity of the abdominal muscles was greater during hypercapnia than during hypoxia. However the two chemical stimuli also resulted in different tidal volume (VT) and respiratory frequency responses at any given minute volume of ventilation. When EMG activity was reanalyzed as a function of VT, EMGeo and EMGta were the same for a given VT whether induced by hypercapnia or hypoxia, but EMGdi was consistently greater during hypoxia than during hypercapnia. When the vagus nerves were blocked by cooling exteriorized cervical vagal loops, all abdominal muscle EMG activity was abolished. The findings support the concept that stimulation of the central and peripheral chemoreceptors results in asymmetric activation of the inspiratory and expiratory respiratory muscles. The findings also indicate that afferent vagal stimuli play an important facilitatory role in activation of the abdominal expiratory muscles.

Responses of the anterolateral abdominal muscles during cough and expiratory threshold loading in the cat

2000 ◽  
Vol 88 (4) ◽  
pp. 1207-1214 ◽  
Author(s):  
Donald C. Bolser ◽  
Paul J. Reier ◽  
Paul W. Davenport
Keyword(s):  
Abdominal Muscle ◽  
Rectus Abdominis ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Cough Reflex ◽  
Gastric Pressure ◽  
Simultaneous Activation ◽  
External Oblique ◽  
Internal Oblique

The present study was conducted to determine the pattern of activation of the anterolateral abdominal muscles during the cough reflex. Electromyograms (EMGs) of the rectus abdominis, external oblique, internal oblique, transversus abdominis, and parasternal muscles were recorded along with gastric pressure in anesthetized cats. Cough was produced by mechanical stimulation of the lumen of the intrathoracic trachea or larynx. The pattern of EMG activation of these muscles during cough was compared with that during graded expiratory threshold loading (ETL; 1–30 cmH2O). ETL elicited differential recruitment of abdominal muscle EMG activity (transversus abdominis > internal oblique > rectus abdominis ≅ external oblique). In contrast, both laryngeal and tracheobronchial cough resulted in simultaneous activation of all four anterolateral abdominal muscles with peak EMG amplitudes 3- to 10-fold greater than those observed during the largest ETL. Gastric pressures during laryngeal and tracheobronchial cough were at least eightfold greater than those produced by the largest ETL. These results suggest that, unlike their behavior during expiratory loading, the anterolateral abdominal muscles act as a unit during cough.

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.

The effects of curl-up exercise in terms of posture and muscle contraction direction on muscle activity and thickness of trunk muscles

2020 ◽  
Vol 33 (5) ◽  
pp. 857-863
Author(s):  
Sun-Young Ha ◽  
DooChul Shin
Keyword(s):  
Muscle Contraction ◽  
Muscle Activity ◽  
Muscle Thickness ◽  
Transversus Abdominis ◽  
Trunk Muscles ◽  
Abdominal Muscles ◽  
Significant Difference ◽  
Effective Angle ◽  
External Oblique ◽  
Internal Oblique

BACKGROUND: The curl-up exercise is widely used in clinical practice for strengthening abdominal muscles, but has been applied without a systematic method. OBJECTIVE: The purpose of this study was to determine the most effective method considering the angle and muscle contraction direction during the curl-up exercise. METHODS: Fourteen healthy males performed the curl-up exercise according to contraction direction (concentric and eccentric) and angle (30∘, 60∘, and 90∘). The muscle activity of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and iliopsoas (IP) was measured using electromyography (EMG), and the muscle thickness of transversus abdominis (TrA) was measured using ultrasonography. RESULTS: The activities of the abdominal muscles (RA, EO, and IO) decreased with increasing angles (30∘, 60∘, and 90∘) (p< 0.05). There was no significant difference between eccentric and concentric contractions. The thickness ratio of TrA was the largest at an eccentric curl-up at 30∘, and the smallest at a concentric curl-up at 30∘ (p< 0.05). CONCLUSIONS: The most effective angle for curl-up was 30∘. Although there is no difference in the direction of muscle contraction, eccentric curl-up at 30∘ could be considered the most effective posture for abdominal strengthening considering the importance of TrA.

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.

Effects of posture on abdominal muscle shortening in awake dogs

1993 ◽  
Vol 75 (4) ◽  
pp. 1452-1459 ◽  
Author(s):  
A. M. Leevers ◽  
J. D. Road
Keyword(s):  
Respiratory Activity ◽  
Abdominal Muscle ◽  
Rectus Abdominis ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Muscle Shortening ◽  
Lateral Decubitus ◽  
Length Changes ◽  
External Oblique ◽  
Internal Oblique

The objective of this study was to examine the effects of posture on tonic and phasic expiratory activity of the abdominal muscles in awake dogs. Six tracheostomized dogs were chronically instrumented with sonomicrometer transducers and bipolar electromyographic electrodes placed in each of the four abdominal muscles. To determine the effects of posture on tonic and phasic activity of individual abdominal muscles, muscle resting length (Lr) and tidal length changes (%Lr), respectively, were measured in awake dogs in the left lateral decubitus (LLD), sitting, and standing (STAND) positions. The transversus abdominis Lr consistently shortened when the dog was moved from LLD to STAND and lengthened when the dog was moved from LLD to the sitting position, and the external oblique Lr consistently lengthened when the dog went from LLD to STAND. The internal oblique and rectus abdominis had no consistent changes in Lr with a change in position. All four abdominal muscles actively shortened (%Lr) more in the upright positions. In addition, the internal layer (transversus abdominis and internal oblique) actively shortened more than the external layer (rectus abdominis and external oblique). In conclusion, both tonic and phasic respiratory activity of the abdominal muscles, reflected by changes in Lr and %Lr, respectively, were affected by changes in posture.

Abdominal Strengthening Exercises: A Comparative EMG Study

1997 ◽  
Vol 6 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Gloria M. Beim ◽  
Jorge L. Giraldo ◽  
Danny M. Pincivero ◽  
Matthew J. Borror ◽  
Freddie H. Fu
Keyword(s):  
Abdominal Wall ◽  
Muscle Activation ◽  
Anterior Abdominal Wall ◽  
Surface Emg ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Healthy Male ◽  
Strengthening Exercises ◽  
External Oblique ◽  
Internal Oblique

The purpose of this study was to compare electromyographic (EMG) activity of the abdominal muscles between the crunch exercise and five other popular abdominal exercises. Surface EMG recordings of four muscles (upper rectus, lower rectus, external oblique, and internal oblique) of the anterior abdominal wall were collected and analyzed on 20 healthy, male volunteers. EMG activity was recorded during execution of the abdominal crunch, the sit-up, and exercises performed with the Abflex machine, the AbRoller, the Nordic Track Ab Works, and the Nautilus crunch machine. The results indicate that the crunch exercise is comparable to the five other abdominal exercises with respect to muscle activation of the internal and external abdominal oblique muscles. Activation of the upper rectus abdominal muscles appears to be best achieved with the Abflex machine, whereas the crunch exercise is superior to the sit-up for activation of the upper and lower rectus abdominal muscles.

Mechanical role of expiratory muscles during breathing in prone anesthetized dogs

1990 ◽  
Vol 69 (6) ◽  
pp. 2137-2142 ◽  
Author(s):  
G. A. Farkas ◽  
M. A. Schroeder
Keyword(s):  
Spontaneous Breathing ◽  
Muscle Activation ◽  
Transversus Abdominis ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Cervical Vagotomy ◽  
Anesthetized Dogs ◽  
Expiratory Muscles ◽  
External Oblique

The purpose of the present study was to assess the mechanical role of the expiratory muscles during spontaneous breathing in prone animals. The electromyographic (EMG) activity of the triangularis sterni, the rectus abdominis, the external oblique, and the transversus abdominis was studied in 10 dogs light anesthetized with pentobarbital sodium. EMGs were recorded during spontaneous steady-state breathing in supine and prone suspended animals both before and after cervical vagotomy. We also measured the end-expiratory lung volume [functional residual capacity (FRC)] in supine and prone positions to assess the mechanical role of expiratory muscle activation in prone dogs. Spontaneous breathing in the prone posture elicited a significant recruitment of the triangularis sterni, the external oblique, and the transversus abdominis (P less than 0.05). Bilateral cervical vagotomy eliminated the postural activation of the external oblique and the transversus abdominis but not the triangularis sterni. Changes in posture during control and after cervical vagotomy were associated with an increase in FRC. However, changes in FRC, on average, were 132.3 +/- 33.8 (SE) ml larger (P less than 0.01) postvagotomy. We conclude that spontaneous breathing in prone anesthetized dogs is associated with a marked phasic expiratory recruitment of rib cage and abdominal muscles. The present data also indicate that by relaxing at end expiration the expiratory muscles of the abdominal region are directly responsible for generating roughly 40% of the tidal volume.

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