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Physiotherapy Research International :... Oct 2023Pressure biofeedback is a tool that can detect the movement of a structure and may be used as an indicator of muscle function. It's widely used to measure the... (Review)
Review
BACKGROUND AND PURPOSE
Pressure biofeedback is a tool that can detect the movement of a structure and may be used as an indicator of muscle function. It's widely used to measure the transversus abdominis (TrA) muscle activity. Pressure biofeedback (PBU) monitors the abdominal wall movement by measuring the pressure change during abdominal hollowing and can indirectly evaluate the TrA muscle function, which is considered as a valuable tool. The evaluation of the training of core muscles, including the transversus abdominis, requires a reliable outcome. Various methods using different positions are used to evaluate the transversus abdominis muscle function. However, it is noted that a standard way of evaluation and training still needs to be improved in research and clinical practice. This technical report discusses the optimal position and technique to measure the TrA muscle activity using PBU, with discussions on the merits and demerits of the body positions.
METHODS
The technical report is presented with a literature review of the PBU measurement of TrA and through observation in the clinical practice. The evaluation methods of TrA, including the position to activate and isolate, are discussed in detail.
RESULTS
Training core muscles does not imply TrA activation, and evaluating isolated TrA and multifidus is essential before intervention. The abdominal drawing-in maneuver effectively activates TrA in various evaluation positions of the body, but when using PBUs, it would be valid in a prone position.
DISCUSSION
Different body positions are practiced to train TrA and core muscles using PBU, commonly adopted by practice are in supine. It's noted that most of the studies lack in establishing the effectiveness of the position in evaluating the TrA muscle activity using PBU. The need for insight into an appropriate technique for evaluating TrA activity is addressed in this technical report. This report presents key points on the complete technique and concludes that the prone position is superior to other positions and recommended for measuring and recording the TrA activity using a PBU.
Topics: Humans; Muscle Contraction; Abdominal Muscles; Posture; Pressure; Biofeedback, Psychology
PubMed: 37395304
DOI: 10.1002/pri.2033 -
European Journal of Applied Physiology Jul 2024To clarify the association between forced expiration and the abdominal muscles by assessing the relationship between expiratory mouth pressure and abdominal muscle...
PURPOSE
To clarify the association between forced expiration and the abdominal muscles by assessing the relationship between expiratory mouth pressure and abdominal muscle activity in healthy young males.
METHODS
Twenty-five males underwent forced expiration at 20, 30, 50, 75, and 100% of the maximal expiratory mouth pressure. Mouth pressure was measured using a bridge-type transducer connected to a mouth pressure meter. Abdominal crunch, twist crunch, and abdominal hollowing at maximal voluntary contraction were also performed. During forced expiration and abdominal exercises, the activity of the rectus abdominis (RA), oblique externus abdominis/oblique internus abdominis (OE/OI), and OI/transversus abdominis (OI/TrA) was measured using surface electromyography.
RESULTS
The determination coefficient (r) for the linear relationship between mouth pressure and abdominal muscle activity was 0.86 ± 0.15 for the RA, 0.93 ± 0.06 for the OE/OI, and 0.90 ± 0.14 for the OE/OI. The slope of the linear relationship with r ≥ 0.50 showed no significant difference between the RA (0.22 ± 0.27) and the OE/OI (0.27 ± 0.21). However, it was significantly greater in the OI/TrA (1.78 ± 1.41) than in the RA and OE/OI. The OE/OI activity was significantly lower in the maximal forced expiration than in twist crunch, and the OI/TrA activity was not significantly greater in the maximal forced expiration than in twist crunch.
CONCLUSION
All abdominal muscles contribute to forced expiration with a greater contribution of the OI and TrA than the RA and OE. Furthermore, the contribution of the TrA would be greater than that of the OI.
Topics: Humans; Male; Abdominal Muscles; Exhalation; Mouth; Pressure; Young Adult; Adult; Muscle Contraction; Electromyography
PubMed: 38427101
DOI: 10.1007/s00421-024-05430-5 -
Medicina (Kaunas, Lithuania) Feb 2021The maximal abdominal contraction maneuver (MACM) was designed as an effective and efficient breathing exercise to increase the stability of the spinal joint. However,...
The maximal abdominal contraction maneuver (MACM) was designed as an effective and efficient breathing exercise to increase the stability of the spinal joint. However, it has not been determined whether MACM is more effective and efficient than the maximal expiration method. Thus, the present study was undertaken to investigate whole abdominal muscle thickness changes after MACM. Thirty healthy subjects (17 males and 13 females) participated in this study. An experimental comparison between MACM and the maximal expiration task was conducted by measuring the change of abdominal muscle thickness such as the transverse abdominis (TrA), internal oblique (IO), external oblique (EO) and rectus abdominis (RA) using ultrasound images. The results indicated that MACM resulted in significantly greater muscle thickness increases of the TrA and RA than the maximal expiration exercise ( < 0.05). MACM provided better exercise than the maximal expiration exercise in terms of increasing spine stability, at least from a co-contraction perspective.
Topics: Abdominal Muscles; Breathing Exercises; Exercise; Female; Humans; Male; Muscle Contraction; Ultrasonography
PubMed: 33540623
DOI: 10.3390/medicina57020129 -
Reproductive Sciences (Thousand Oaks,... Mar 2017To record and characterize electromyography (EMG) from the uterus and abdominal muscles during the nonlabor to first and second stages of labor and to define...
OBJECTIVE
To record and characterize electromyography (EMG) from the uterus and abdominal muscles during the nonlabor to first and second stages of labor and to define relationships to contractions.
METHODS
Nulliparous patients without any treatments were used (n = 12 nonlabor stage, 48 during first stage and 33 during second stage). Electromyography of both uterine and abdominal muscles was simultaneously recorded from electrodes placed on patients' abdominal surface using filters to separate uterine and abdominal EMG. Contractions of muscles were also recorded using tocodynamometry. Electromyography was characterized by analysis of various parameters.
RESULTS
During the first stage of labor, when abdominal EMG is absent, uterine EMG bursts temporally correspond to contractions. In the second stage, uterine EMG bursts usually occur at same frequency as groups of abdominal bursts and precede abdominal bursts, whereas abdominal EMG bursts correspond to contractions and are accompanied by feelings of "urge to push." Uterine EMG increases progressively from nonlabor to second stage of labor.
CONCLUSIONS
(1) Uterine EMG activity can be separated from abdominal EMG events by filtering. (2) Uterine EMG gradually evolves from the antepartum stage to the first and second stages of labor. (3) Uterine and abdominal EMG reflect electrical activity of the muscles during labor and are valuable to assess uterine and abdominal muscle events that control labor. (4) During the first stage of labor uterine, EMG is responsible for contractions, and during the second stage, both uterine and abdominal muscle participate in labor.
Topics: Abdominal Muscles; Adult; Electromyography; Female; Humans; Labor, Obstetric; Myometrium; Parity; Pregnancy; Uterine Contraction
PubMed: 27436367
DOI: 10.1177/1933719116658704 -
Journal of Sport Rehabilitation Jul 2023Isometric core stability exercises are commonly used to target muscles of the lumbopelvic-hip complex, including the rectus abdominis (RA) and erector spinae (ES). These...
CONTEXT
Isometric core stability exercises are commonly used to target muscles of the lumbopelvic-hip complex, including the rectus abdominis (RA) and erector spinae (ES). These exercises can be implemented in rehabilitation protocols to increase muscle strength and endurance. Difficulty can be progressed by modifying the base of support or adding an unstable element. Load cells can be affixed to suspension training devices to measure force exerted through the straps during exercise. The primary purpose of this study was to assess the relationship between activity of the RA and ES to force measured through a load cell fixed to suspension straps during bilateral and unilateral suspended bridge exercises.
DESIGN
Forty asymptomatic, active individuals completed a single laboratory visit.
METHODS
Participants completed 2 bilateral suspended bridges and 2 unilateral suspended bridges held to failure. Surface electromyography sensors were placed over the bilateral RA and ES to quantify muscle activity (% maximum voluntary isometric contraction). A load cell was affixed to the suspension straps to measure force exerted through the straps throughout the duration of the exercise. Pearson correlations were used to determine relationships between force and muscle activity of the RA and ES throughout exercise duration.
RESULTS
Force was negatively related to RA muscle activity in bilateral suspended bridges (r = -.735 to -.842, P < .001) and unilateral suspended bridges (r = -.300 to -.707, P = .002 to <.001). Force had a positive relationship with ES muscle activity in bilateral suspended bridges (r = .689 to .791, P < .001) and unilateral suspended bridges (r = .418 to .448, P < .001).
CONCLUSIONS
Suspended bridge exercises can be a valuable tool to target posterior abdominal musculature such as the ES to contribute to core stability and endurance. Load cells can be applied during suspension training to quantify the interaction between individuals and the exercise equipment.
Topics: Humans; Exercise Therapy; Exercise; Abdominal Muscles; Electromyography; Rectus Abdominis; Muscle, Skeletal
PubMed: 37146988
DOI: 10.1123/jsr.2022-0307 -
Musculoskeletal Science & Practice Dec 2020Active Straight Leg Raise (ASLR) is a clinical test that challenges lumbopelvic stability and have been used in low back pain patients. There are reports of positive...
BACKGROUND
Active Straight Leg Raise (ASLR) is a clinical test that challenges lumbopelvic stability and have been used in low back pain patients. There are reports of positive tests in asymptomatic individuals, however, it is not clear if they are false positives or a consequence of performing the test differently.
OBJECTIVES
To compare abdominal muscles activity and pelvic motion during an ASLR between adults with chronic low back pain and asymptomatic participants with a positive and negative ASLR test.
DESIGN
Cross-sectional study design.
METHOD
Nineteen volunteers with chronic nonspecific low back pain (LBP) and 19 asymptomatic, 12 with a negative ASLR (AG-) and 7 with a positive ASLR test (AG+) were assessed while performing an ASLR (dynamic postural challenge). Pelvic rotation and medio-lateral center of pressure displacement (COPml), as well as bilateral EMG abdominal muscles activity were assessed. Muscles asymmetry index were also analyzed. Kruskal-wallis test was used to compare groups (α = 0.05).
RESULTS
Both LBP and AG + displayed significantly less contralateral internal oblique/transversus abdominis (IO/TrA) muscle activation than AG- (p = 0.003 and p = 0.005, respectively) and also more asymmetry between sides in the IO/TrA than AG- (p = 0.022 and p = 0.004, respectively). No significant differences between LBP and AG+ were found (p > 0.05).
CONCLUSION
A positive ASLR test in an asymptomatic person could be more than a false positive, since IO/TrA muscle activation appears to be lower and more asymmetrical in people with a positive ASLR test, both with and without low back pain. Future studies may consider removing asymptomatic individuals with a positive ASLR.
Topics: Abdominal Muscles; Adult; Cross-Sectional Studies; Humans; Leg; Low Back Pain; Muscle Contraction
PubMed: 32919292
DOI: 10.1016/j.msksp.2020.102245 -
Journal of Neurophysiology May 2018Recordings of alpha motoneuron discharges from branches of the intercostal and abdominal nerves in anesthetized cats were analyzed for modulation during the cardiac...
Recordings of alpha motoneuron discharges from branches of the intercostal and abdominal nerves in anesthetized cats were analyzed for modulation during the cardiac cycle. Cardiac modulation was assessed by the construction of cross-correlation histograms between the R-wave of the ECG and the largest amplitude efferent spikes. In all but two recordings (which were believed to have either no or few alpha spikes), the histograms showed relatively short duration peaks and/or troughs (widths at half amplitude 4-50 ms) at lags of 10-150 ms. These observations were deduced to result from activity in oligosynaptic pathways, probably from muscle spindle afferents, whose discharges are known to be synchronized to the cardiac pulse. The results suggest that onward transmission of the cardiac signal from thoracic muscle afferents (and possibly from other dynamically sensitive afferents) to other parts of the central nervous system is highly likely and that therefore these afferents could contribute to cardiac interoception. NEW & NOTEWORTHY It has been recognized since 1933 that muscle spindles respond to the cardiac pulse, but it is unknown whether this cardiac signal is transmitted to other levels in the nervous system. Here we show that a cardiac signal, likely arising from muscle spindles, is present in the efferent activities of thoracic and abdominal muscle nerves, suggesting probable onward transmission of this signal to higher levels and therefore that muscle spindles could contribute to cardiac interoception.
Topics: Abdominal Muscles; Animals; Cardiovascular Physiological Phenomena; Cats; Electrocardiography; Female; Intercostal Muscles; Intercostal Nerves; Interoception; Male; Motor Neurons; Muscle Spindles; Spinal Cord; Thoracic Vertebrae
PubMed: 29412777
DOI: 10.1152/jn.00025.2018 -
Journal of Bodywork and Movement... Apr 2022Suspension training reportedly enhances core musculature co-contraction. This study investigated whether the use of a suspension trainer increases core musculature...
Suspension training reportedly enhances core musculature co-contraction. This study investigated whether the use of a suspension trainer increases core musculature co-activation during exercises vs. its floor counterpart. Participants were 25 healthy volunteers (16 men, 9 women; age: 27.24 ± 4.02 years). Wireless electromyography electrodes were placed bilaterally at the rectus abdominis (RA), erector spinae (ES), and abdominal obliques (OB). Test order (push-up, bridge, and prone plank) was randomized (exercise and condition) with a 3-min rest period between tests. Co-contraction ratios between muscle groups were estimated by root mean square. Ratios (RA/ES, RA/OB, ES/OB) were analyzed using paired t-tests (P ≤ .05). For all floor exercises, co-contraction of core musculature was significantly higher than suspension trainer. During suspension training, perturbations due to increased agonist activation without similar increases in antagonists may be too intense for untrained or injured individuals. Individuals lacking muscle control to recruit muscles concurrently may benefit from mastering traditional floor exercises to promote joint stiffness and stability before suspension trainer exercises.
Topics: Abdominal Muscles; Adult; Electromyography; Exercise; Exercise Therapy; Female; Humans; Male; Rectus Abdominis; Young Adult
PubMed: 35500983
DOI: 10.1016/j.jbmt.2022.02.018 -
Plastic and Reconstructive Surgery Feb 2022Abdominal bulging at the donor site of free abdominal flaps for breast reconstruction is a common postoperative complication. In addition to the thickness of abdominal...
BACKGROUND
Abdominal bulging at the donor site of free abdominal flaps for breast reconstruction is a common postoperative complication. In addition to the thickness of abdominal muscles, the authors identified the rectus abdominis diastasis as an important factor that compromises abdominal wall strength. This study aimed to assess the relationship between preoperative abdominal wall strength and postoperative abdominal bulging.
METHODS
A total of 224 patients were enrolled in this study. Patient demographics, the rectus and lateral abdominis muscle thicknesses, and the rate of rectus abdominis diastasis were compared (with versus without bulging). Muscle thickness and rectus abdominis diastasis were investigated by preoperative computed tomography.
RESULTS
The group with bulging consisted of 32 patients (14.3 percent), whereas the group without bulging consisted of 192 patients. The group with bulging had a significantly higher gestational history rate. The thickness of the rectus abdominis muscle in the group with bulging was significantly thinner (median, 8.6 mm versus 10.5 mm; p < 0.001) and the rate of rectus abdominis diastasis was significantly higher (78.1 percent versus 32.3 percent; p < 0.001). There were no significant differences with respect to the thickness of the lateral abdominal muscle and the other factors (i.e., age, body mass index, history of laparotomy. and operative details).
CONCLUSIONS
Because the diagnosis of abdominal bulging was based on severity, the rate may be high compared to that reported from previous studies. Because the factor of gestational history correlated to thickness of the rectus abdominis muscle and rectus abdominis diastasis, this factor influenced the occurrence of abdominal bulging. Patients with a thin rectus abdominis muscle and rectus abdominis diastasis were at higher risk of abdominal bulging.
CLINICAL QUESTION/LEVEL OF EVIDENCE
Risk, III.
Topics: Abdominal Muscles; Abdominal Wall; Adult; Case-Control Studies; Diastasis, Muscle; Female; Free Tissue Flaps; Humans; Mammaplasty; Middle Aged; Muscle Strength; Postoperative Complications; Preoperative Period; Retrospective Studies; Transplant Donor Site
PubMed: 35077427
DOI: 10.1097/PRS.0000000000008763 -
Biology of Sex Differences 2017Optimal function of the abdominal muscles is necessary for several life functions including lifting and carrying tasks. Sex differences in strength and fatigability are... (Comparative Study)
Comparative Study
BACKGROUND
Optimal function of the abdominal muscles is necessary for several life functions including lifting and carrying tasks. Sex differences in strength and fatigability are established for many limb muscles and back extensor muscles, but it is unknown if sex differences exist for the abdominal muscles despite their functional importance.
METHODS
Eighteen females (24.3 ± 4.8 years) and 15 males (24.1 ± 6.6 years) performed (1) isometric trunk flexion maximal voluntary contractions (MVCs) in a range of trunk positions to establish a torque-angle curve and (2) submaximal (50% MVC), intermittent isometric contraction (6 s on, 4 s off) until task failure to determine fatigability of the trunk flexor muscles. Dual X-ray absorptiometry quantified body fat and lean mass. Physical activity levels were quantified with a questionnaire. Torque-angle curves, electromyography (EMG), MVC torque, and torque steadiness were compared with repeated measures ANOVA with sex as a between-subjects factor.
RESULTS
For the torque-angle curve, MVC torque was reduced as the trunk angle increased toward flexion ( < 0.001). Males had greater MVC torque than females at the extended positions (31% difference), with no sex differences in torque in upright sitting ( 0.05). Time-to-task failure for the submaximal fatigability task in upright sitting was similar between males and females (12.4 ± 7 vs 10.5 ± 6 min). Time-to-task failure was positively associated with strength ( = 0.473, = 0.005) and self-reported physical activity ( = 0.456, = 0.030). Lean mass in the trunk was positively associated with trunk flexor strength ( = 0.378, = 0.011) and self-reported physical activity ( = 0.486, = 0.007). Finally, torque steadiness [coefficient of variation of torque (CV)] during submaximal isometric contractions decreased with contraction intensity and was similar for males and females across all intensities.
CONCLUSIONS
Unlike many limb muscle groups, males and females had similar fatigability and torque steadiness of the trunk flexor muscles during isometric contractions. Stronger individuals, however, exhibited less fatigability. Lower self-reported physical activity was associated with greater fatigability of trunk flexor muscles. The relationship between strength and fatigability of the trunk flexor muscles and physical activity supports the importance of abdominal muscle strengthening to offset fatigability in both males and females.
Topics: Abdominal Muscles; Adolescent; Adult; Electromyography; Exercise; Female; Humans; Isometric Contraction; Male; Muscle Fatigue; Torque; Torso; Young Adult
PubMed: 28428836
DOI: 10.1186/s13293-017-0133-y