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.

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.

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.

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.

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 Are There Any Differences in Abdominal Activation between Women and Men during Hypopressive Exercises?

2021 ◽  
Vol 18 (13) ◽  
pp. 6984
Author(s):  
Iria Da Cuña-Carrera ◽  
Alejandra Alonso-Calvete ◽  
Eva M. Lantarón-Caeiro ◽  
Mercedes Soto-González
Keyword(s):  
Observational Study ◽  
Healthy Subjects ◽  
Muscle Thickness ◽  
Standing Position ◽  
Rectus Abdominis ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
External Oblique ◽  
Internal Oblique ◽  
Significant Activation

This study analyzes the effects of hypopressive exercises on the abdominal thickness of healthy subjects and compares the performance between women and men. We conducted a transversal observational study in 98 subjects (63% women). The muscle thickness is analyzed in transversus abdominis, internal oblique, external oblique, and rectus abdominis with ultrasound imaging at rest and during the hypopressive exercise (HE) in supine and standing position. Comparisons between rest and hypopressive exercise are carried out in the two different positions and between women and men. In the supine position, there is a significant activation of the transversus abdominis and internal oblique during hypopressive exercise (p < 0.001), and it is similar in both sexes, the external oblique is only activated significantly by men (p < 0.001) and rectus abdominis had no significant activation (p > 0.05). Our results show that standing transversus abdominis and external oblique significantly increased their thickness during HE with higher effects in men. Internal oblique also increased significantly, but with higher effects in women, and rectus abdominis had no significant increase. Men had similar effects to women during HE, with an activation of the deepest abdominal muscles. The unequal anatomy and the position could explain the different results obtained between the sexes.

Abdominal muscle use during breathing in unanesthetized dogs

1989 ◽  
Vol 66 (1) ◽  
pp. 20-27 ◽  
Author(s):  
A. De Troyer ◽  
J. J. Gilmartin ◽  
V. Ninane
Keyword(s):  
Respiratory Muscle ◽  
Abdominal Muscle ◽  
Rectus Abdominis ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Quiet Breathing ◽  
Sitting Posture ◽  
Cervical Vagotomy ◽  
External Oblique ◽  
Conscious Animals

The pattern of abdominal muscle use during breathing in unanesthetized dogs is unknown. Therefore, we have recorded the electromyograms of the rectus abdominis, external oblique, and transversus abdominis in eight conscious animals breathing quietly in the sitting, standing, and prone postures. During quiet breathing in the sitting posture, all animals invariably had a large amount of phasic expiratory activity in the transversus abdominis. In contrast, only four animals showed some expiratory activity in the external oblique, and only one animal had expiratory activity in the rectus abdominis. A similar pattern was observed when the animals were standing or lying prone, although the amount of expiratory activity was less in this posture. Bilateral cervical vagotomy in four animals did not affect the degree of transversus abdominis expiratory activation or the influence of posture. We conclude that in conscious dogs 1) the abdominal muscles play an important role during breathing and make spontaneous quiet expiration a very active process, 2) the transversus abdominis is the primary respiratory muscle of the abdomen, and 3) unlike in anesthetized animals, extrapulmonary receptors play a major role in promoting abdominal expiratory contraction.

Changes in abdominal muscles architecture induced by different types of breathing

2021 ◽  
pp. 1-7
Author(s):  
Iria Da Cuña-Carrera ◽  
Alejandra Alonso-Calvete ◽  
Yoana González-González ◽  
Mercedes Soto-González
Keyword(s):  
Effect Size ◽  
Health Care Professionals ◽  
Rectus Abdominis ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Healthy Population ◽  
Different Types ◽  
Architectural Characteristics ◽  
And Behavior ◽  
Internal Oblique

BACKGROUND: The underlying morphology and behavior of abdominal muscles during breathing are still lacking in knowledge in healthy population. OBJECTIVE: To analyze the effects of three different types of breathing on the architectural characteristics of abdominal muscles. METHODS: Ninety-eight healthy subjects were measured to assess the effects of breathing on the abdominal muscles, subjects performed three different types of breathing and the muscular thickness was measured with ultrasound imaging, analyzing also the differences between sexes. RESULTS: During the three different types of breathing and in comparison with the resting state, an increase of the thickness has been reported in the transversus abdominis (p< 0.001; effect size = 2.44, very large) and internal oblique (p< 0.001; effect size = 1.04, moderate) in both sexes, but with a higher increase in men. External oblique and rectus abdominis increased their thickness through breathing only while the lips were with pursed (p< 0.05) with trivial effect sizes and only differences between sexes were found in rectus abdominis. CONCLUSIONS: All breathings activated the deepest abdominal muscles, but the most superficial were only activated with lips pursed. Moreover, men appeared to activate more the deepest abdominal muscles but also the rectus abdominis. Findings in this study support the use of different types of breathing depending on the muscle to be activated or the sex, helping health care professionals to address their interventions on the abdominal muscles with a more focused approach.

scholarly journals Impact of acute ascites on the action of the canine abdominal muscles

2008 ◽  
Vol 104 (6) ◽  
pp. 1568-1573 ◽  
Author(s):  
Dimitri Leduc ◽  
André De Troyer
Keyword(s):  
Muscle Length ◽  
Abdominal Muscle ◽  
Transversus Abdominis ◽  
Oblique Muscle ◽  
Abdominal Muscles ◽  
Cross Sectional ◽  
Control Value ◽  
Airway Opening ◽  
Internal Oblique ◽  
Resting Muscle

Although ascites causes abdominal expansion, its effects on abdominal muscle function are uncertain. In the present study, progressively increasing ascites was induced in supine anesthetized dogs, and the changes in abdominal (ΔPab) and airway opening (ΔPao) pressure obtained during stimulation of the internal oblique and transversus abdominis muscles were measured; the changes in internal oblique muscle length were also measured. As ascites increased from 0 to 100 ml/kg body wt, Pab and muscle length during relaxation increased. ΔPab also showed a threefold increase ( P < 0.001). However, ΔPao decreased ( P < 0.001). When ascites increased further to 200 ml/kg, resting muscle length continued to increase and muscle shortening during stimulation became very small so that active muscle length was 155% of the resting muscle length in the control condition. Concomitantly, ΔPab returned to the control value, and ΔPao continued to decrease. Similar results were obtained with the animals in the head-up posture, although the decrease in ΔPao appeared only when ascites was greater than 125 ml/kg. It is concluded that 1) ascites adversely affects the expiratory action of the abdominal muscles on the lung; 2) this effect results primarily from the increase in diaphragm elastance; and 3) when ascites is severe, the abdomen cross-sectional area is also increased and the abdominal muscles are excessively lengthened so that their active pressure-generating ability itself is reduced.

Changes in the neural drive to abdominal expiratory muscles in hemorrhagic hypotension

1994 ◽  
Vol 266 (6) ◽  
pp. H2423-H2429 ◽  
Author(s):  
R. F. Fregosi
Keyword(s):  
Pulmonary Ventilation ◽  
Respiratory Rhythm ◽  
Abdominal Muscle ◽  
Rectus Abdominis ◽  
Abdominal Muscles ◽  
Neural Drive ◽  
Hemorrhagic Hypotension ◽  
Severe Hypotension ◽  
Expiratory Muscles ◽  
External Oblique

The purpose of this study was to test the hypothesis that hemorrhage-induced hypotension increases the neural drive to the abdominal expiratory muscles in chloralose-urethan-anesthetized cats that are studied under conditions of constant arterial PCO2 (PaCO2) and hyperoxia. A secondary aim was to describe in detail the concomitant changes in inspired pulmonary ventilation (VI) and the pattern of breathing under these conditions. The rectified and integrated electromyogram (EMG) of the external oblique and rectus abdominis muscles and VI were recorded in moderate and severe hemorrhagic hypotension, leading to reductions in mean blood pressure of approximately 30 and 60%, respectively. The PaCO2 was prevented from falling, and the arterial PO2 was maintained at a hyperoxic level (> 200 mmHg) by adding CO2 and O2 to the inspired gas mixture. VI increased by 2.5- and 5-fold in moderate and severe hypotension (P < 0.05). The changes in VI were mediated exclusively by changes in tidal volume, indicating that the reflex did not alter the activity of respiratory rhythm-generating structures. The EMG of external oblique muscles averaged 2, 44, and 100% in control conditions and in moderate and severe hypotension, respectively; corresponding values in rectus abdominis muscles were 10, 28, and 100% (P < 0.05 for both muscles). Bilateral cervical vagotomy caused a one- to three-fold decrease in the ventilatory response to hemorrhage and abolished the increase in abdominal muscle EMG activities. In conclusion, hemorrhagic hypotension reflexly increases pulmonary ventilation and the neural drive to the abdominal muscles. The reflex is vagally mediated, but the location of the receptors was not identified.

scholarly journals Effects of Cesarean Section and Vaginal Delivery on Abdominal Muscles and Fasciae

Medicina ◽  
2020 ◽  
Vol 56 (6) ◽  
pp. 260 ◽  
Author(s):  
Chenglei Fan ◽  
Diego Guidolin ◽  
Serena Ragazzo ◽  
Caterina Fede ◽  
Carmelo Pirri ◽  
...  
Keyword(s):  
Cesarean Section ◽  
Vaginal Delivery ◽  
Rectus Sheath ◽  
Transversus Abdominis ◽  
Abdominal Muscles ◽  
Linea Alba ◽  
Pain Duration ◽  
External Oblique ◽  
Internal Oblique

Background and objectives: Possible disorders after delivery may interfere with the quality of life. The aim of this study was to ascertain whether abdominal muscles and fasciae differ in women depending on whether they experienced transverse cesarean section (CS) or vaginal delivery (VA) in comparison with healthy nulliparous (NU). Materials and methods: The thicknesses of abdominal muscles and fasciae were evaluated by ultrasound in 13 CS, 10 VA, and 13 NU women (we examined rectus abdominis (RA); external oblique (EO); internal oblique (IO); transversus abdominis (TrA); total abdominal muscles (TAM = EO + IO + TrA); inter-rectus distance (IRD); thickness of linea alba (TLA); rectus sheath (RS), which includes anterior fascia of RS and posterior fascia of RS (P-RS); loose connective tissue between sublayers of P-RS (LCT); abdominal perimuscular fasciae (APF), which includes anterior fascia of EO, fasciae between EO, IO, and TrA, and posterior fascia of TrA). Data on pain intensity, duration, and location were collected. Results: Compared with NU women, CS women had wider IRD (p = 0.004), thinner left RA (p = 0.020), thicker right RS (p = 0.035) and APF (left: p = 0.001; right: p = 0.001), and IO dissymmetry (p = 0.009). VA women had thinner RA (left: p = 0.008, right: p = 0.043) and left TAM (p = 0.024), mainly due to left IO (p = 0.027) and RA dissymmetry (p = 0.035). However, CS women had thicker LCT (left: p = 0.036, right: p < 0.001), APF (left: p = 0.014; right: p = 0.007), and right IO (p = 0.028) than VA women. There were significant correlations between pain duration and the affected fasciae/muscles in CS women. Conclusions: CS women showed significant alterations in both abdominal fasciae and muscle thicknesses, whereas VA women showed alterations mainly in muscles. Thinner RA and/or dissymmetric IO, wider IRD, and thicker LCT and APF after CS may cause muscle deficits and alteration of fascial gliding, which may induce scar, abdominal, low back, and/or pelvic pain.

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