scholarly journals Connections between expiratory bulbospinal neurons and expiratory motoneurons in thoracic and upper lumbar segments of the spinal cord

2013 ◽  
Vol 109 (7) ◽  
pp. 1837-1851 ◽  
Author(s):  
J. D. Road ◽  
T. W. Ford ◽  
P. A. Kirkwood
Keyword(s):  
Cross Correlation ◽  
Intercostal Nerve ◽  
Oblique Muscle ◽  
Abdominal Muscles ◽  
Intercostal Muscle ◽  
Nerve Branch ◽  
Monosynaptic Connection ◽  
Distal Branch ◽  
Caudal Medulla ◽  
Thoracic And Abdominal

Cross-correlation of neural discharges was used to investigate the connections between expiratory bulbospinal neurons (EBSNs) in the caudal medulla and expiratory motoneurons innervating thoracic and abdominal muscles in anesthetized cats. Peaks were seen in the cross-correlation histograms for around half of the EBSN-nerve pairs for the following: at T8, the nerve branches innervating internal intercostal muscle and external abdominal oblique muscle and a more distal branch of the internal intercostal nerve; and at L1, a nerve branch innervating internal abdominal oblique muscle and a more distal branch of the ventral ramus. Fewer peaks were seen for the L1 nerve innervating external abdominal oblique, but a paucity of presumed α-motoneuron discharges could explain the rarity of the peaks in this instance. Taking into account individual EBSN conduction times to T8 and to L1, as well as peripheral conduction times, nearly all of the peaks were interpreted as representing monosynaptic connections. Individual EBSNs showed connections at both T8 and L1, but without any discernible pattern. The overall strength of the monosynaptic connection from EBSNs at L1 was found to be very similar to that at T8, which was previously argued to be substantial and responsible for the temporal patterns of expiratory motoneuron discharges. However, we argue that other inputs are required to create the stereotyped spatial patterns of discharges in the thoracic and abdominal musculature.

Comparison among low intensity bridge exercises using suspension devices based on muscle activity and subjective difficulty

2021 ◽  
pp. 1-6
Author(s):  
Sang-Yeol Lee ◽  
Se-Yeon Park
Keyword(s):  
Inclination Angle ◽  
Muscle Activity ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Oblique Muscle ◽  
Abdominal Muscles ◽  
Internal Oblique Muscle ◽  
Low Intensity ◽  
Erector Spinae Muscle ◽  
Internal Oblique

BACKGROUND: Recent clinical studies have revealed the advantages of using suspension devices. Although the supine, lateral, and forward leaning bridge exercises are low-intensity exercises with suspension devices, there is a lack of studies directly comparing exercise progression by measuring muscular activity and subjective difficulty. OBJECTIVE: To identify how the variations in the bridge exercise affects trunk muscle activity, the present study investigated changes in neuromuscular activation during low-intensity bridge exercises. We furthermore explored whether the height of the suspension point affects muscle activation and subjective difficulty. METHODS: Nineteen asymptomatic male participants were included. Three bridge exercise positions, supine bridge (SB), lateral bridge (LB), forward leaning (FL), and two exercise angles (15 and 30 degrees) were administered, thereby comparing six bridge exercise conditions with suspension devices. Surface electromyography and subjective difficulty data were collected. RESULTS: The rectus abdominis activity was significantly higher with the LB and FL exercises compared with the SB exercise (p< 0.05). The erector spinae muscle activity was significantly higher with the SB and LB exercises, compared with the FL exercise (p< 0.05). The LB exercise significantly increased the internal oblique muscle activity, compared with other exercise variations (p< 0.05). The inclination angle of the exercise only affected the internal oblique muscle and subjective difficulty, which were significantly higher at 30 degrees compared with 15 degrees (p< 0.05). CONCLUSIONS: Relatively higher inclination angle was not effective in overall activation of the trunk muscles; however, different bridge-type exercises could selectively activate the trunk muscles. The LB and SB exercises could be good options for stimulating the internal oblique abdominis, and the erector spinae muscle, while the FL exercise could minimize the erector spinae activity and activate the abdominal muscles.

Comparison of core stabilization techniques on ultrasound imaging of the diaphragm, and core muscle thickness and external abdominal oblique muscle electromyography activity

2021 ◽  
pp. 1-9
Author(s):  
Jaejin Lee ◽  
Dohyun Kim ◽  
Yoonkyum Shin ◽  
Chunghwi Yi ◽  
Hyeseon Jeon ◽  
...  
Keyword(s):  
Muscle Thickness ◽  
Random Order ◽  
Abdominal Muscle ◽  
Core Stability ◽  
Oblique Muscle ◽  
Abdominal Muscles ◽  
Amplitude Analysis ◽  
Core Stabilization ◽  
Co Activation ◽  
Pressure Biofeedback

BACKGROUND: To restore core stability, abdominal drawing-in maneuver (ADIM), abdominal bracing (AB), and dynamic neuromuscular stabilization (DNS) have been employed but outcome measures varied and one intervention was not superior over another. OBJECTIVE: The purpose of this study was to compare the differential effects of ADIM, AB, and DNS on diaphragm movement, abdominal muscle thickness difference, and external abdominal oblique (EO) electromyography (EMG) amplitude. METHODS: Forty-one participants with core instability participated in this study. The subjects performed ADIM, AB, and DNS in random order. A Simi Aktisys and Pressure Biofeedback Unit (PBU) were utilized to measure core stability, an ultrasound was utilized to measure diaphragm movement and measure abdominal muscles thickness and EMG was utilized to measure EO amplitude. Analysis of variance (ANOVA) was conducted at P< 0.05. RESULTS: Diaphragm descending movement and transverse abdominis (TrA) and internal abdominal oblique (IO) thickness differences were significantly increased in DNS compared to ADIM and AB (P< 0.05). EO amplitude was significantly increased in AB compared to ADIM, and DNS. CONCLUSIONS: DNS was the best technique to provide balanced co-activation of the diaphragm and TrA with relatively less contraction of EO and subsequently producing motor control for efficient core stabilization.

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.

On the issue of radical inguinal hernia surgery

1936 ◽  
Vol 32 (7) ◽  
pp. 892-892
Author(s):  
B. Ivanov
Keyword(s):  
Inguinal Hernia ◽  
Spermatic Cord ◽  
Inguinal Canal ◽  
Oblique Muscle ◽  
Abdominal Muscles ◽  
Hernia Surgery ◽  
Internal Oblique Muscle ◽  
Hernial Sac ◽  
Inguinal Hernia Surgery ◽  
Internal Oblique

Stiasnу, H. K Describes his method of radical inguinal hernia surgery, which he recommended for cases where a simple Bassi operation is not applicable due to the weakness of the fascia and abdominal muscles, to strengthen the weakest parts of the inguinal canal the lower inguinal triangle and the site of the spermatic cord exit , the hernial sac, after its isolation from the latter, is cut off as high as possible, and the cord after the incision of the internal oblique muscle of the abdomen is pushed upward at an angle of 45-90 .

Cerebral cortical evoked potentials elicited by cat intercostal muscle mechanoreceptors

1993 ◽  
Vol 74 (2) ◽  
pp. 799-804 ◽  
Author(s):  
P. W. Davenport ◽  
R. Shannon ◽  
A. Mercak ◽  
R. L. Reep ◽  
B. G. Lindsey
Keyword(s):  
Electrical Stimulation ◽  
Evoked Potentials ◽  
Sensorimotor Cortex ◽  
Muscle Mechanics ◽  
Muscle Spindles ◽  
Intercostal Nerve ◽  
Muscle Afferents ◽  
Cortical Activation ◽  
Intercostal Muscle ◽  
Cortical Evoked Potentials

Intercostal muscle afferents discharge in response to changes in intercostal muscle mechanics and have spinal and brain stem projections. It was hypothesized that intercostal muscle mechanoreceptors also project to the sensorimotor cortex. In cats, the proximal muscle branch of an intercostal nerve was used for electrical stimulation. The mechanical stimulation was stretch of an isolated intercostal space. The sensorimotor cortex was mapped with a surface ball electrode. Primary cortical evoked potentials (CEP) were found in area 3a of the sensorimotor cortex with mechanical and electrical stimulation. The CEP was elicited with the smallest stretch amplitude used, 50 microns. The CEP response showed little increase beyond 300-microns stretch. The CEP elicited by 50-microns stretch suggests an initial cortical activation by intercostal muscle spindles. The minimal increase in CEP amplitude with stretch > 300 microns suggests that the CEP response is primarily due to muscle spindle recruitment. The increase in amplitude beyond this stretch may be due to recruitment of tendon organs. These results demonstrate a short-latency projection of intercostal muscle mechanoreceptors to the sensorimotor region of the cerebral cortex. This cortical activation may be involved in respiratory sensations and/or transcortical reflex responses to changes in respiratory muscle mechanics.

scholarly journals Absence of synergy for monosynaptic Group I inputs between abdominal and internal intercostal motoneurons

2014 ◽  
Vol 112 (5) ◽  
pp. 1159-1168 ◽  
Author(s):  
T. W. Ford ◽  
C. F. Meehan ◽  
P. A. Kirkwood
Keyword(s):  
Intercostal Nerve ◽  
Abdominal Muscle ◽  
Transversus Abdominis ◽  
Intercostal Muscle ◽  
Group I ◽  
Group A ◽  
Muscle Groups ◽  
Group B ◽  
Motor Acts ◽  
Stimulation Of

Internal intercostal and abdominal motoneurons are strongly coactivated during expiration. We investigated whether that synergy was paralleled by synergistic Group I reflex excitation. Intracellular recordings were made from motoneurons of the internal intercostal nerve of T8 in anesthetized cats, and the specificity of the monosynaptic connections from afferents in each of the two main branches of this nerve was investigated. Motoneurons were shown by antidromic excitation to innervate three muscle groups: external abdominal oblique [EO; innervated by the lateral branch (Lat)], the region of the internal intercostal muscle proximal to the branch point (IIm), and muscles innervated from the distal remainder (Dist). Strong specificity was observed, only 2 of 54 motoneurons showing excitatory postsynaptic potentials (EPSPs) from both Lat and Dist. No EO motoneurons showed an EPSP from Dist, and no IIm motoneurons showed one from Lat. Expiratory Dist motoneurons fell into two groups. Those with Dist EPSPs and none from Lat ( group A) were assumed to innervate distal internal intercostal muscle. Those with Lat EPSPs ( group B) were assumed to innervate abdominal muscle (transversus abdominis or rectus abdominis). Inspiratory Dist motoneurons (assumed to innervate interchondral muscle) showed Dist EPSPs. Stimulation of dorsal ramus nerves gave EPSPs in 12 instances, 9 being in group B Dist motoneurons. The complete absence of heteronymous monosynaptic Group I reflex excitation between muscles that are synergistically activated in expiration leads us to conclude that such connections from muscle spindle afferents of the thoracic nerves have little role in controlling expiratory movements but, where present, support other motor acts.

Respiratory muscle control during vomiting

1990 ◽  
Vol 68 (2) ◽  
pp. 237-241 ◽  
Author(s):  
Alan D. Miller
Keyword(s):  
Response Pattern ◽  
Respiratory Muscles ◽  
Respiratory Neurons ◽  
Abdominal Muscles ◽  
Inspiratory Muscles ◽  
Medullary Respiratory Neurons ◽  
Gastric Contents ◽  
Expiratory Neurons ◽  
Expiratory Muscles ◽  
Thoracic And Abdominal

The changes in thoracic and abdominal pressures that generate vomiting are produced by coordinated action of the major respiratory muscles. During vomiting, the diaphragm and external intercostal (inspiratory) muscles co-contract with abdominal (expiratory) muscles in a series of bursts of activity that culminates in expulsion. Internal intercostal (expiratory) muscles contract out of phase with these muscles during retching and are inactive during expulsion. The periesophageal portion of the diaphragm relaxes during expulsion, presumably facilitating rostral movement of gastric contents. Recent studies have begun to examine to what extent medullary respiratory neurons are involved in the control of these muscles during vomiting. Bulbospinal expiratory neurons in the ventral respiratory group caudal to the obex discharge at the appropriate time during (fictive) vomiting to activate either abdominal or internal intercostal motoneurons. The pathways that drive phrenic and external intercostal motoneurons during vomiting have yet to be identified. Most bulbospinal inspiratory neurons in the dorsal and ventral respiratory groups do not have the appropriate response pattern to initiate activation of these motoneurons during (fictive) vomiting. Relaxation of the periesophageal diaphragm during vomiting could be brought about, at least in part, by reduced firing of bulbospinal inspiratory neurons.Key words: brain stem, bulbospinal respiratory neurons, vomiting center critique, diaphragm, abdominal muscles.

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.

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