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Applied Ergonomics Sep 2017We assessed whether participants are able to perform abdominal bracing during lifting, and described its effects on trunk muscle activity and body kinematics. Fourteen...
We assessed whether participants are able to perform abdominal bracing during lifting, and described its effects on trunk muscle activity and body kinematics. Fourteen participants performed 10 lifts (symmetrical lifting of a 15 kg load from floor level), 5 with abdominal bracing and 5 without. Activity of the lumbar multifidus (LM) and internal oblique (IO) muscles, and trunk and lower body kinematics were obtained. During non-bracing lifting, IO activity did not increase beyond rested standing levels (with average muscle activity ranging between 8.2 and 9.1% maximum voluntary contraction; %MVC), while LM activity did (range: 8.5-21.0 %MVC). During bracing lifting, muscle activity was higher compared to non-bracing in IO and LM at the start of the lift (with average between condition differences up to 10.9 %MVC). Upper leg, pelvis and lumbar spine angles were smaller, but thorax flexion angles were larger while lifting with bracing compared to without (with average between condition differences ranging from 0.7° to 4.3°). Although participants do not typically brace their abdominal muscles while lifting, they can be trained to do so. There appears to be no clear advantage of abdominal bracing during lifting, leaving its value for low-back pain prevention unclear.
Topics: Abdominal Muscles; Adult; Back Muscles; Biomechanical Phenomena; Braces; Female; Humans; Lifting; Male; Posture; Range of Motion, Articular; Task Performance and Analysis; Torso; Weight-Bearing; Young Adult
PubMed: 28502411
DOI: 10.1016/j.apergo.2017.04.009 -
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 -
Neurourology and Urodynamics Feb 2020To measure the neuromuscular activation of the pelvic floor and abdominal muscles concurrently with vaginal closure forces induced during a hypopressive exercise (HE)...
AIM
To measure the neuromuscular activation of the pelvic floor and abdominal muscles concurrently with vaginal closure forces induced during a hypopressive exercise (HE) and to identify the contribution of the HEs sequences (posture and maneuver) in the muscle's activation.
METHODS
A cross-sectional study design was employed. Sixty-six women who had participated in a physical therapy program focused on HEs were recruited. Pelvic floor muscle (PFM) activation was measured using surface electromyography (sEMG) in supine and in the orthostatic position, and vaginal closure force was measured through vaginal dynamometry in supine. Activation of the abdominal, gluteal, and hip adductor muscles was measured using sEMG. Maximum effort voluntary contractions (MVCs) of the PFMs and reference contractions of the abdominal and hip muscles were acquired for normalization purposes. A HE was then performed in a supine position with one leg raised, then in an orthostatic position.
RESULTS
During the supine HE, the peak PFM sEMG amplitude was 74.4% to 86.5% (49.6%-109.6%) of MVC, the peak vaginal closure force was between 51.2% and 55.7% (95.5%-382.9%) of MVC, and the muscles of the lateral abdominal wall were activated between 25.4% and 35.3% of the reference contraction. During the orthostatic HE, PFM activation was 61.4% (40.1%-105.6%) of MVC, and the lateral abdominal wall muscles contracted at 22.8% of the reference activation level.
CONCLUSIONS
The PFMs, abdominal, gluteal, and adductor muscles are activated during the performance of a HE. The activation level of the PFMs and abdominal muscles is likely insufficient to result in strength gains; however, they could have an endurance effect.
Topics: Abdominal Muscles; Adult; Cross-Sectional Studies; Electromyography; Exercise Therapy; Female; Humans; Middle Aged; Muscle Contraction; Muscle Strength; Muscle, Skeletal; Pelvic Floor; Pelvic Floor Disorders; Physical Therapy Modalities; Posture; Vagina
PubMed: 31985114
DOI: 10.1002/nau.24284 -
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 -
International Urogynecology Journal Feb 2024Stress urinary incontinence (SUI) primarily results from the weakness of pelvic floor muscles, working synergistically with the abdominal muscles. The current study...
INTRODUCTION AND HYPOTHESIS
Stress urinary incontinence (SUI) primarily results from the weakness of pelvic floor muscles, working synergistically with the abdominal muscles. The current study aimed to compare thickness and contractile function of lateral abdominal muscles in women with and without SUI.
METHODS
Thirty-nine women with SUI (SUI group; age: 38.87 ± 8.96 years, body mass index (BMI): 24.03 (5.94) kg/m) and 42 healthy women (control group; age: 36.21 ± 11.46 years, BMI: 23.90 (5.85) kg/m) were included. Transverse abdominis (TrA) and internal oblique (IO) muscle thickness at rest and during abdominal drawing-in maneuver (ADIM) were measured with ultrasound imaging in B-mode using a Logiq S7/Expert device and a 9-11 MHz linear transducer. Percentage change in thickness and contractile function of these muscles were also calculated.
RESULTS
No significant differences in the thickness of TrA and IO muscles at rest and during ADIM between the groups were found (p > 0.05). The percent change in thickness and contractile function of both right and left side TrA muscles and the right side IO muscle were lower in SUI group than control group (p < 0.05). The percentage change in thickness and the contractile function of the left side IO muscle did not change (p > 0.05).
CONCLUSION
Women with SUI had a smaller percentage change in thickness and contractile function of TrA and IO muscle than women without SUI. However, there was no difference in the morphological features of these muscles between the groups. Considering the lateral abdominal muscle, training may be important for management of SUI.
Topics: Humans; Female; Adult; Middle Aged; Young Adult; Urinary Incontinence, Stress; Abdominal Muscles; Muscle Contraction; Ultrasonography; Pelvis
PubMed: 37599308
DOI: 10.1007/s00192-023-05636-9 -
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 -
Journal of Ultrasound in Medicine :... Nov 2015The activity of abdominal muscles mainly produces high expiratory pressure. These include the rectus abdominis, external oblique, internal oblique, and transverse...
OBJECTIVES
The activity of abdominal muscles mainly produces high expiratory pressure. These include the rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles. The purpose of this study was to determine whether maximal expiratory pressure is associated with each abdominal muscle thickness at rest.
METHODS
Thirty-nine healthy male volunteers (mean age ± SD, 20.7 ± 2.7 years) participated in the study. The thickness of the right rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles was measured by B-mode sonography in the supine position. The maximal expiratory pressure was obtained with a spirometer in the sitting position. The correlations between each abdominal muscle thickness and maximal expiratory pressure were determined by the Pearson correlation coefficient.
RESULTS
The correlation coefficient between the rectus abdominis muscle and maximal expiratory pressure was 0.571 (P< .001). Correlation coefficients between the external oblique, internal oblique, and transverse abdominis muscles and maximal expiratory pressure were 0.297 (P = .066), 0.267 (P = .100), and 0.022 (P = .894), respectively.
CONCLUSIONS
Our results indicate that the rectus abdominis muscle thickness might be more highly correlated with expiratory pressure production than the external oblique, internal oblique, and transverse abdominis muscle thickness.
Topics: Abdominal Muscles; Exhalation; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Male; Organ Size; Physical Exertion; Pressure; Reproducibility of Results; Sensitivity and Specificity; Statistics as Topic; Ultrasonography; Young Adult
PubMed: 26396169
DOI: 10.7863/ultra.14.12006 -
Disability and Rehabilitation Aug 2021The purpose of this study was to understand the relationship between abdominal muscle strength and recovery of upper limb function, after adjusting for various...
PURPOSE
The purpose of this study was to understand the relationship between abdominal muscle strength and recovery of upper limb function, after adjusting for various confounding factors, such as age, gender, and sensory function.
METHODS
We retrospectively analyzed data of 78 sub-acute stroke patients with mild-to-moderate upper limb dysfunction. Participants were divided into two groups, strong and weak, according to the abdominal muscle strength. The improvement of scores on the Simple Test for Evaluating Hand Function was compared between the groups. We employed propensity score matching to adjust for numerous relevant variables, including age, affected side, duration from onset, upper limb function, grip strength, sensory function, visuospatial perception, motivation, and cognitive function at admission.
RESULTS
The improvement of scores on the Simple Test for Evaluating Hand Function of the strong group was significantly larger than the weak one, both before and after matching. This trend was noted in the subgroup analysis of participants with moderate dysfunction on admission; however; the trend was not clearly noticeable in participants with mild dysfunction.
CONCLUSIONS
Our results suggest that abdominal muscle strength is significantly associated with the recovery of upper limb function in sub-acute stroke patients, especially in those with moderate upper limb dysfunction.Implications for RehabilitationAbdominal muscle strength is associated with the recovery of upper limb function in subacute stroke patients with moderate upper limb dysfunction.Abdominal muscle strength can be used as a predictive factor for the prognosis of upper limb function in stroke patients.
Topics: Abdominal Muscles; Hand Strength; Humans; Muscle Strength; Propensity Score; Recovery of Function; Retrospective Studies; Stroke; Stroke Rehabilitation; Upper Extremity
PubMed: 31874062
DOI: 10.1080/09638288.2019.1706104 -
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 -
Journal of Physical Activity & Health Apr 2022Using data from a multiethnic cohort, the authors tested associations of multiple types and intensities of physical activity (PA) with abdominal muscle area and density.
BACKGROUND
Using data from a multiethnic cohort, the authors tested associations of multiple types and intensities of physical activity (PA) with abdominal muscle area and density.
METHODS
1895 Multiethnic Study of Atherosclerosis participants (mean age 64.6 [9.6] y) completed health history and PA questionnaires and computed tomography to quantify body composition and measurements of cardiovascular and inflammatory biomarkers. Analyses included multivariable regression.
RESULTS
Compared with those not meeting PA guidelines for Americans, those meeting the guidelines had higher total abdominal muscle area (odds ratio, 95% confidence interval 1.60, 1.20 to 2.15), stability muscle area (1.68, 1.28 to 2.20), and stability muscle density (1.35, 1.03 to 1.76). After adjustment for relevant covariates, each SD increase in total moderate to vigorous PA was associated with a higher total abdominal (β, 95% confidence interval = 0.068, 0.036 to 0.173), stability (0.063, 0.027 to 0.099), and locomotor (0.069, 0.039 to 0.099) muscle area and higher locomotor muscle density (0.065, 0.022 to 0.108, P < .01). Only intentional and conditioning exercise were associated with total abdominal and stability muscle density (P < .05). Light PA and walking were not associated with muscle area or density.
CONCLUSIONS
Most types of PA are positively associated with abdominal muscle area and density across functional categories, independent of relevant covariates. These results provide additional evidence for promoting PA for healthy muscle aging.
Topics: Abdominal Muscles; Atherosclerosis; Body Composition; Cardiovascular System; Exercise; Humans; Middle Aged
PubMed: 35276663
DOI: 10.1123/jpah.2021-0409