Intra-abdominal pressure correlates with abdominal wall tension during clinical evaluation tests

Changes of abdominal wall tension across various resistance exercises during maximal and submaximal loads in healthy adults: a cross-sectional study

INTRODUCTION

Resistance exercises are effective for maintaining health and activating stabilizing muscles, as they trigger abdominal wall tension responses. This study compared the effects of multi-joint and single-joint, upper-body and lower-body exercises (Lat pulldown, Rows, Peck deck, Chest press, Biceps curls, Triceps extensions, French-Press, Step up, Hip abduction/adduction, Squat, Leg press, Romanian deadlift, Hamstring curls) performed at maximal and submaximal intensities.

METHODS

This cross-sectional study included 12 men and 18 women (age:47.8 ± 5.9 years, height:174.8 ± 10.2 cm, weight: 77.7 ± 15.4 kg, BMI:25.3 ± 3.6), who wore a noninvasive sensor Ohmbelt to measure abdominal wall tension performing exercises at 15 repetition maximum (RM), 10RM, 5RM, and 1RM. Differences across exercises and sex were compared by Friedman test with Durbin-Conover post-hoc, and intensities were analyzed by Wilcoxon test.

RESULTS

The study found significant differences (p < 0.05) in abdominal wall tension changes based on the type of exercise and training intensity. Multi-joint lower-body exercises, such as the Romanian deadlift, dumbbell front squat, and leg press, led to the greatest increases in abdominal tension in both sexes in comparison to single-joint upper-body exercises. Males had higher abdominal wall tension changes than females (p < 0.05) at 1RM, 5RM, and 10RM. However, no significant difference was found at 15RM, indicating that lower intensities produce similar abdominal wall tension changes in both sexes.

CONCLUSIONS

This study showed that multi-joint lower-body exercises were found to produce greatest abdominal wall tension increases, especially compared to single-joint upper-body exercises. The abdominal wall tension was higher in males than females due to higher loads, emphasizing the need for exercise-specific approaches.

A Study on 10-Week Combined Aerobic and Resistance Training Exercise Prescription for Female Patients with Pelvic Floor Dysfunction

Background/Objectives: Female pelvic floor dysfunction (FPFD) is a prevalent condition affecting postpartum women. This study aims to evaluate the effectiveness of a 10-week combined aerobic and resistance training exercise prescription in improving pelvic floor muscle strength and function in postpartum women with FPFD. Methods: Thirty postpartum women diagnosed with FPFD underwent a 10-week exercise intervention. This study adopted a single-group pre-post design. Pelvic floor muscle electromyography assessment indicators were measured before and after the intervention. Results: The exercise intervention significantly improved the maximum value of fast-twitch muscle fibers (type II) and the average value of slow-twitch muscle fibers (type I) while reducing resting tension and variability. Conclusions: A 10-week combined aerobic and resistance training exercise prescription effectively improves pelvic floor muscle strength in postpartum women. It enhances the maximum value of fast-twitch (type II) muscle fibers, reduces rise and recovery times, and improves slow-twitch (type I) muscle fiber function, including increasing the mean value and reducing variability, rise time, and recovery time.

Retroperitoneal leakage as an important cause of acquired ultrafiltration decline in peritoneal dialysis: clinical characteristics and related risk factors

BACKGROUND

Peritoneal dialysis (PD) is a widely-used renal replacement therapy while low ultrafiltration volume usually results in technique failure. Retroperitoneal leakage has been reported to be one of the causes of acquired decline in ultrafiltration. The present study investigated retroperitoneal leakage in PD patients and explored related risk factors.

METHODS

This study was designed as a prospective, observational study. A total of 420 PD patients regularly followed up at our center were enrolled from May 2011 to July 2021 and followed until December 2021. Retroperitoneal leakage was determined by magnetic resonance peritoneography and was used as the endpoint. Patients with retroperitoneal leakage were given intermittent PD or temporary hemodialysis (HD) as therapy. Cox regression models were used to identify risk factors for retroperitoneal leakage.

RESULTS

The cohort was followed up for up to 125.0 months (median: 46.4 months; interquartile range: 16.6 months). During the follow-up, 68 patients developed retroperitoneal leakage, with 31 (45.6%) cases occurring within the first year after PD initiation. A total of 62 (91.2%) patients recovered from retroperitoneal leakage and resumed their original PD regimen. Multivariate Cox regression analysis revealed that age and gender were independent predictors for retroperitoneal leakage. Younger males were more likely to develop retroperitoneal leakage. In females, waistline and body mass index (BMI) were found to be risk factors for retroperitoneal leakage.

CONCLUSIONS

Retroperitoneal leakage was common in PD patients with ultrafiltration insufficiency and was usually reversible after appropriate treatment. Age and gender were independent risk factors for retroperitoneal leakage.

Inter-rater reliability of the dynamic neuromuscular stabilization diaphragm tests among individuals with non-specific low back pain and neck pain

BACKGROUND

The Dynamic Neuromuscular Stabilization (DNS) diaphragm test and intra-abdominal pressure regulation test (IAPRT) are qualitative clinical tests that assess postural stability provided by the diaphragm.

OBJECTIVE

Evaluate the inter-rater reliability of the diaphragm test and IAPRT between an experienced and novice DNS clinician among individuals with non-specific low back pain (LBP) and neck pain.

METHODS

Forty-five participants with non-specific LBP and/or neck pain were assessed by an experienced and novice DNS physiotherapist in the diaphragm test and IAPRT, and scored on a visual analog scale (VAS) according to five different criteria.

RESULTS

Moderate reliability was noted when assessing LBP and neck pain patients in the diaphragm test and IAPRT (p < 0.001). Moderate reliability also existed when assessing only LBP (p < 0.001) or neck pain (p = 0.002, p = 0.009) independently. Patients with lower pain (NPRS score of 5 or < ) demonstrated lower intra-class correlation coefficients, yet still moderate reliability in the diaphragm test (p = 0.004) and IAPRT (p = 0.001). Patients with higher pain (NPRS score of 6 or > ) demonstrated greater intra-class correlation coefficients, with the diaphragm test resulting in good reliability (p < 0.001).

CONCLUSIONS

The diaphragm test and IAPRT demonstrate moderate reliability between an experienced and novice DNS clinician when evaluating LBP and neck pain patients, with a greater degree of reliability noted in patients suffering from higher reported pain.

Physiologic tension of the abdominal wall

BACKGROUND

Tension-free abdominal closure is a primary tenet of laparotomy. But this concept neglects the baseline tension of the abdominal wall. Ideally, abdominal closure should be tailored to restore native physiologic tension. We sought to quantify the tension needed to re-establish the linea alba in patients undergoing exploratory laparotomy.

METHODS

Patients without ventral hernias undergoing laparotomy at a single institution were enrolled from December 2021 to September 2022. Patients who had undergone prior laparotomy were included. Exclusion criteria included prior incisional hernia repair, presence of an ostomy, large-volume ascites, and large intra-abdominal tumors. After laparotomy, a sterilizable tensiometer measured the quantitative tension needed to bring the fascial edge to the midline. Outcomes included the force needed to bring the fascial edge to the midline and the association of BMI, incision length, and prior lateral incisions on abdominal wall tension.

RESULTS

This study included 86 patients, for a total of 172 measurements (right and left for each patient). Median patient BMI was 26.4 kg/m2 (IQR 22.9;31.5), and median incision length was 17.0 cm (IQR 14;20). Mean tension needed to bring the myofascial edge to the midline was 0.97 lbs. (SD 1.03). Mixed-effect multivariable regression modeling found that increasing BMI and greater incision length were associated with higher abdominal wall tension (coefficient 0.04, 95% CI [0.01,0.07]; p = 0.004, coefficient 0.04, 95% CI [0.01,0.07]; p = 0.006, respectively).

CONCLUSION

In patients undergoing laparotomy, the tension needed to re-establish the linea alba is approximately 1.94 lbs. A quantitative understanding of baseline abdominal wall tension may help surgeons tailor abdominal closure in complex scenarios, including ventral hernia repairs and open or burst abdomens.

Biomechanical and tissue reaction: the effects of varying sutures size on canine abdominal wall stitching

Objective

Larger diameter sutures can provide sufficient tensile strength to surgical incisions but may exacerbate the inflammatory response caused by the amount of implanted foreign material. This experiment aims to investigate the differences in biomechanical stability and tissue reactivity after suturing canine midline abdominal incisions with different suture sizes.

Method

Assessing the biomechanical differences between USP 2-0, 3-0, and 4-0 PGA sutures using uniaxial tensile testing on ex vivo canine midline skin and fascial muscle tissues using either a simple continuous or simple interrupted technique. mRNA and protein expression levels of inflammatory factors were measured through RT-PCR and ELISA. Tissue reactivity was evaluated using a semi-quantitative scoring system.

Result

For strains below 30% in skin and below 50% in muscle, there were no significant differences among groups. The results of skin biomechanical testing showed that the USP 4-0 PGA suture group demonstrated significantly lower maximum tensile strength compared to the USP 2-0 PGA or USP 3-0 PGA suture groups. However, it remained capable of providing at least 56.3 N (1.03 MPa) tensile strength for canine skin incisions, matching the tensile strength requirements of general canine abdominal wall surgical incisions. In addition, there were no statistically significant differences observed in the maximum tensile strength among different size of sutures according to the data of biomechanical testing in muscle. Larger diameter sutures led to increased levels of inflammatory factors (IL-1β, IL-6, TNF-ɑ) and tissue reactivity. Simple interrupted sutures caused higher levels of inflammatory factors in muscular tissue compared to simple continuous sutures.

Conclusion

USP 4-0 PGA sutures provide sufficient biomechanical stability for suturing canine abdominal skin and linea alba. Suture size significantly influences tissue reactivity after suturing, with smaller gauge sutures reducing early tissue inflammatory response. Thus, USP 4-0 PGA suture has more advantages to suturing canine abdominal surgical incisions.

The effect of abdominal bracing on respiration during a lifting task: a cross-sectional study

BACKGROUND

Abdominal bracing is a maneuver widely used by rehabilitation specialists and sports trainers to improve spinal stability. This study aimed to investigate how lifting tasks with and without abdominal bracing affect the respiratory function of the diaphragm.

METHODS

M-mode ultrasonographic assessment of diaphragmatic motion combined with spirometry was performed on 31 healthy adults. Participants were asked to breathe continuously whilst lifting a load with spontaneous abdominal muscle contraction (natural loaded breathing) and abdominal bracing (AB loaded breathing).

RESULTS

Pearson's correlations revealed strong correlations between ultrasonography and spirometry measures (p < 0.001) for all types of breathing: tidal breathing (r = 0.709, r2 = 0.503), natural loaded breathing (r = 0.731, r2 = 0.534) and AB loaded breathing (r = 0.795, r2 = 0.632). Using paired-samples t-tests, the natural loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p < 0.001) but not during expiration (p = .101). Spirometry demonstrated lower lung volumes (L) at the end of inspiration and expiration (p < 0.001), with no changes in total lung volume (p = 0.06). The AB loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p = 0.002) but not during expiration (p = 0.05). Spirometry demonstrated lower lung volumes at the end of inspiration (p < 0.001), expiration (p = 0.002), and total lung volumes (p = 0.019).

CONCLUSION

This study demonstrated that abdominal bracing performed during a lifting task reduces lung volume despite an increase in diaphragmatic motion. Diaphragm excursions strongly correlate with lung volumes even under postural loading.

TRIAL REGISTRATION

The study was prospectively registered on 8 April 2021 at ClinicalTrials.gov with identification number NCT04841109.

CT-measured hernia parameters can predict component separation: a cross-sectional study from China

PURPOSE

Currently, there are no reliable preoperative methods for predicting component separation (CS) during incisional hernia repair. By quantitatively measuring preoperative computed tomography (CT) imaging, we aimed to assess the value of hernia defect size, abdominal wall muscle quality, and hernia volume in predicting CS.

METHODS

The data of 102 patients who underwent open Rives-Stoppa retro-muscular mesh repair for midline incisional hernia between January 2019 and March 2022 were retrospectively analyzed. The patients were divided into two groups: ''CS group'' patients who required CS to attempt fascial closure, and ''non-CS'' group patients who required only Rives-Stoppa retro-muscular release to achieve fascial closure. Hernia defect width, hernia defect angle, rectus width, abdominal wall muscle area and CT attenuation, hernia volume (HV), and abdominal cavity volume (ACV) were measured on CT images. The rectus width to defect width ratio (RDR), HV/ACV, and HV/peritoneal volume (PV; i.e., HV + ACV) were calculated. Differences between the indices of the two groups were compared. Logistic regression models were applied to analyze the relationships between the above CT parameters and CS. Receiver operator characteristic (ROC) curves were generated to evaluate the potential utility of CT parameters in predicting CS.

RESULTS

Of the102 patients, 69 were in the non-CS group and 33 were in the CS group. Compared with the non-CS group, hernia defect width (P < 0.001), hernia defect angle (P < 0.001), and hernia volume (P < 0.001) were larger in the CS group, while RDR (P < 0.001) was smaller. The abdominal wall muscle area in the CS group was slightly greater than that in the non-CS group (P = 0.046), and there was no significant difference in the CT attenuation of the abdominal wall muscle between the two groups (P = 0.089). Multivariate logistic regression identified hernia defect width (OR 1.815, 95% CI 1.428-2.308, P < 0.001), RDR (OR 0.018, 95% CI 0.003-0.106, P < 0.001), hernia defect angle (OR 1.077, 95% CI 1.042-1.114, P < 0.001), hernia volume (OR 1.002, 95% CI 1.001-1.003, P < 0.001), and CT attenuation of abdominal wall muscle (OR 0.962, 95% CI 0.927-0.998, P = 0.037) as independent predictors of CS. Hernia defect width was the best predictor for CS, with a cut-off point of 9.2 cm and an area under the curve (AUC) of 0.890. The AUCs of RDR, hernia defect angle, hernia volume, and abdominal wall muscle CT attenuation were 0.843, 0.812, 0.747, and 0.572, respectively.

CONCLUSION

Quantitative CT measurements are of great value for preoperative prediction of CS. Hernia defect size, hernia volume, and the CT attenuation of abdominal wall muscle are all preoperative predictive indicators of CS.

Effects of axial extension on pelvic floor displacement and abdominal muscle activity during a pelvic floor muscle task

BACKGROUND

The effects of axial extension on pelvic floor displacement and abdominal muscle activity during pelvic floor muscle (PFM) exercises are not well known.

OBJECTIVE

To clarify the effect of sitting axial extension on pelvic floor displacement and abdominal muscle activity during a PFM task.

METHODS

Pelvic floor displacement, abdominal muscle activity, and subjective kinesthesia of the PFM were compared between the resting and axial-extended sitting positions during a pelvic floor task in 34 healthy young men.

RESULTS

No significant difference in pelvic floor displacement was observed between the resting and axial extension sitting position. Subjective kinesthesia was significantly easier to perform in axial extension than in resting sitting position during pelvic floor depression. Abdominal oblique muscle activity was higher in axial extension than in resting sitting position during pelvic floor depression. The changes in axial extension were significantly greater in the internal oblique muscles during elevation and in the internal and external oblique muscles during depression than in the lower rectus abdominis muscles.

CONCLUSION

Axial extension in the sitting position does not change pelvic floor displacement during the PFM task. However, axial extension may be effective in facilitating subjective kinesthesia of PFM and in increasing oblique abdominal muscle activity.

Postural-respiratory function of the diaphragm assessed by M-mode ultrasonography

OBJECTIVES

The diaphragm changes position and respiratory excursions during postural loading. However, it is unclear how it reacts to lifting a load while breath-holding or breathing with simultaneous voluntary contraction of the abdominal muscles (VCAM). This study analyzed diaphragm motion in healthy individuals during various postural-respiratory situations.

METHODS

31 healthy participants underwent examination of the diaphragm using M-mode ultrasonography, spirometry, and abdominal wall tension (AWT) measurements. All recordings were performed simultaneously during three consecutive scenarios, i.e., 1. Lifting a load without breathing; 2. Lifting a load and breathing naturally; 3. Lifting a load and breathing with simultaneous VCAM.

RESULTS

Using paired-samples t-tests, lifting a load without breathing displaced the diaphragm's expiratory position more caudally (P < .001), with no change noted in the inspiratory position (P = .373). During lifting a load breathing naturally, caudal displacement of the diaphragm's inspiratory position was presented (P < .001), with no change noted in the expiratory position (P = 0.20) compared to tidal breathing. Total diaphragm excursion was greater when loaded (P = .002). Lifting a load and breathing with VCAM demonstrated no significant changes in diaphragm position for inspiration, expiration, or total excursion compared to natural loaded breathing. For all scenarios, AWT measures were greater when lifting a load (P < .001).

CONCLUSION

In healthy individuals, caudal displacement and greater excursions of the diaphragm occurred when lifting a load. The postural function of the diaphragm is independent of its respiratory activity and is not reduced by the increase in AWT.

Comparison of yoga and dynamic neuromuscular stabilization exercise in chronic low back pain on magnetic resonance imaging of lumbar multifidus- protocol for a randomized controlled trial

Background

Degeneration of Lumbar muscle in chronic low back pain (CLBP) is characterized by an increase in fat infiltration of paraspinal muscle, decrease in the cross-sectional area (CSA) of lumbar multifidus muscle (LMM) and increased thickness of Thoracolumbar fascia (TLF) by 25%. The study objective is to compare the effects of yoga and dynamic neuromuscular stabilization (DNS) exercise on CSA, fat infiltration of LMM with magnetic resonance imaging (MRI), and TLF thickness using musculoskeletal ultrasound imaging (MSK-USI) in CLBP.

Methods

One hundred and forty-four participants with CLBP, which persisted longer than three months, will be recruited for this trial. Both group interventions focused on LMM. The experimental group will receive structured yoga sessions, and the Control Group will receive exercise based on DNS. In each group, exercises will be performed for 3–5 days/week and progressed for 12 weeks. Baseline data will be collected, followed by the recording of primary outcome measure (MRI) and secondary outcome measures (MSK-USI, Oswestry disability index, visual analogue score, optimism, self-efficacy, mood, physical activity, fear of movement, pain catastrophizing, and coping) at baseline and the end of 12th weeks. The normality of data will be verified. Based on the data distribution, within-group analysis and between-group analysis will be performed.

Discussion

This will be the first RCT to compare the effect of yoga and DNS exercise among chronic low back pain participants. This will provide evidence of these interventions' impact on CSA, fat infiltration of LMM, and thickness of TLF in CLBP.

Registration number

CTRI/2021/08/035984 (This trial was registered prospectively).

Electromyographic Comparison of an Abdominal Rise on a Ball with a Traditional Crunch

We propose a new exercise, the abdominal rise on the ball, to replace the traditional crunch in exercise programs. The aim of this study is to compare the activity of the abdominal muscles when performing an ARB with the same activity when performing a traditional crunch. Twenty healthy adults participated in the study. Surface electromyography (EMG) was recorded from the upper and lower rectus abdominis (URA, LRA), internal oblique (IO), external oblique (EO), transversus abdominis (TrA), and erector spinae (ES). EMG values were normalized to maximal voluntary isometric contraction. A paired t-test, nonparametric Wilcoxon test and correlation coefficient were used for statistical analysis. The normalized EMG values of EO, TrA and ES, were statistically significantly higher during the abdominal rise on the ball compared to the traditional crunch, while URA, LRA and IO were significantly lower during the abdominal rise on the ball compared to the traditional crunch. TrA, EO and IO are sufficiently activated during an abdominal rise on a ball, so the exercise could be deemed effective for strengthening these muscles.