External Oblique Research Articles

Effect of expiratory muscle training on respiratory muscle fatigue in healthy adults: a randomized controlled trial.

[Purpose] This study examined the effects of expiratory muscle training on fatigue in individual respiratory muscles. [Participants and Methods] Healthy adult males (n=31) were randomly assigned to two groups: expiratory muscle training (n=15) and normal controls (n=16). In the expiratory muscle training group, training was performed once for 15 min at 50% load of the maximum expiratory mouth pressure twice daily for 4 weeks. Respiratory muscle fatigue indicators were measured using surface electromyography as the median power frequency of each respiratory muscle at the time of measuring the maximum inspiratory mouth pressure during 20 min of inspiratory muscle loading and maximum expiratory mouth pressure. [Results] In the expiratory muscle training group, the median power frequency values of the sternocleidomastoid, rectus abdominis, and internal oblique/external oblique before expiratory muscle training significantly decreased during inspiratory muscle loading. However, no difference was observed in the median power frequency values measured before and during inspiratory muscle loading after the expiratory muscle training. In the normal controls, the median power frequency values of the sternocleidomastoid and rectus abdominis significantly decreased during inspiratory muscle loading. [Conclusion] Expiratory muscle training increased fatigue tolerance of the sternocleidomastoid, rectus abdominis, and internal and external oblique muscles in healthy individuals.

Resistance training modalities: comparative analysis of effects on physical fitness, isokinetic muscle functions, and core muscle biomechanics.

This study aimed to evaluate the effects of varied resistance training modalities on physical fitness components, body composition, maximal strength assessed by one-repetition maximum (1RM), isokinetic muscle functions of the shoulder and knee joints, and biomechanical properties of core muscles. Forty participants were randomly assigned to four groups: control group (CG, n = 10), compound set training group (CSG, n = 10), pyramid set training group (PSG, n = 10), and superset training group (SSG, n = 10). Excluding the CG, the other three groups underwent an 8-week resistance training program, three sessions per week, at 60%-80% of 1RM intensity for 60-90min per session. Assessments included body composition, physical fitness components, 1RM, isokinetic muscle functions, and biomechanical properties (muscle frequency, stiffness, etc.) of the rectus abdominis and external oblique muscles. The PSG demonstrated the most significant improvement in relative peak torque during isokinetic testing of the shoulder and knee joints. Compared to the CG, all exercise groups exhibited positive effects on back strength, sprint performance, 1RM, and core muscle biomechanics. Notably, the PSG showed superior enhancement in external oblique stiffness. However, no significant differences were observed among the exercise groups for rectus abdominis biomechanical properties. Structured resistance training effectively improved maximal strength, functional performance, and core muscle biomechanics. The pyramidal training modality conferred specific benefits for isokinetic muscle functions and external oblique stiffness, suggesting its efficacy in enhancing force production capabilities and core stability.

Thickness of the abdominal wall and pelvic floor dysfunctions in men who practice crossfit vs no crossfit: An observational study.

The objective of this study is to compare the thickness of the transverse abdominis, internal oblique, external oblique, rectus abdominis, and rectus abdominis distance, the quality of life (SF-36), the presence of chronic pelvic pain (CPPQ-Mohedo), and sexual dysfunction (IIEF) in men who practice CrossFit® versus men who do not. Sixty-four healthy men with an average age of 37.19 were recruited at a private sports club and divided into two groups for this cross-sectional observational study. Additionally, participants completed the CPPQ-M, IIEF, and SF-36 questionnaires. Significant differences were found in the thickness of the internal oblique at rest (p = 0.018, d = 0.61), which was greater in the CrossFit® group. In the SF-36 quality of life questionnaire (p = 0.05, d = 0.50), the CrossFit® group also obtained a higher score. CrossFit® improves the quality of life and self-esteem of the participants, in addition to increasing the thickness of the internal oblique. Neither more chronic pelvic pain nor more erectile dysfunction was observed in the CrossFit® group.

Ultrasound-guided muscle dissection for lumboperitoneal shunting via lateral abdominal laparotomy.

Purpose;Lumboperitoneal shunting (LPS) is a common procedure for treating idiopathic normal pressure hydrocephalus (iNPH), involving two abdominal approaches:anterior abdominal laparotomy and lateral abdominal laparotomy (LAL). While LAL is advantageous in terms of infection risk, it presents challenges such as muscle manipulation and potential deviation from the desired trajectory. This report presents a novel technique that utilizes ultrasound examination of the lateral abdominal wall (UELAW) to visualize the three muscle layers (external oblique, internal oblique, and transversus abdominis) before abdominal manipulation during LAL. Illustrative Case;An 83-year-old iNPH patient underwent LPS with this approach, ensuring precise alignment of the trajectory and successful access to the abdominal cavity. Following the procedure, the patient experienced an improvement in gait disturbance and was discharged without any surgical complications. Conclusion;The use of UELAW during LPS provides clear visualization of the abdominal muscle layers, allowing surgeons to perform the procedure with confidence and accuracy, minimizing the risk of trajectory deviation, and ultimately improving patient outcomes. J. Med. Invest. 71 : 343-345, August, 2024.

Comparison of Surgical Results of Modified Stoppa and Ilioinguinal Approach in Patients with Acetabular Fractures Involving Quadrilateral Surface Fractures.

The aim of this study was to evaluate the results of surgical treatment in patients with acetabular fractures with a fractured quadrilateral surface treated using two different approaches. The study included 106 patients who were operated on with ilioinguinal (group A) or modified Stoppa (group B) technique for acetabular fracture with a fractured quadrilateral surface between 2011 and 2020 in our clinic. The quality of reduction was evaluated according to Matta criteria and postoperative pelvic (anteroposterior, external oblique, iliac oblique) radiographs. Evaluation of hip function was recorded using the Merle d'aubigne and Postel Score and Harris Hip Score. Among the patients included in the study, there were 45 patients in group A and 61 patients in group B. When the group data were compared, it was seen that the modified Stoppa approach was superior in terms of intraoperative reduction quality, radiological data, Harris hip score, Merle d'aubigne and PostelScore. (Respectively p=0.40, p=0.49, p=0.040, p=0.028). : Modified Stoppa approach has successful clinical and radiological outcomes and better reduction quality and hip scores than ilioinguinal approaches in acetabular fractures involving quadrilateral plates.

Analyzing muscle thickness changes in lateral abdominal muscles while exercising using virtual reality.

[Purpose] Virtual reality (VR) rehabilitation has become popular in the medical field. VR-guided exercises (VR-ge) have demonstrated positive effects on gait and trunk control. Trunk muscle activation, particularly that of the transversus abdominis (TrA), is responsible for these improvements. However, the difference in muscle activation between VR and real space remains unclear. Therefore, this study aimed to clarify the differences in trunk muscle activation during exercise therapy performed in VR and real space. [Participants and Methods] A total of 22 healthy male volunteers were divided into two equal groups: VR-ge and Control exercise (C-e) groups. Both groups performed reaching exercises in a seated position. Ultrasound imaging was used to measure the thicknesses of the right external oblique, internal oblique, and TrA muscles, both at rest and during the reaching exercises performed in six different directions. [Results] No significant differences were observed in TrA muscle thickness changes between the groups before the intervention. However, after the intervention, the VR-ge group showed significantly greater TrA muscle thickness changes during reaching compared to that of the C-e group. [Conclusion] VR-ge increased TrA activation during reaching compared to exercising in real space.

Effects of progessive vs. constant protocol whole-body vibration on muscle activation, pain, disability and functional performance in non-specific chronic low back pain patients: a randomized clinical trial.

Non-specific chronic low back pain (NSCLBP) is a prevalent condition causing significant disability and functional impairment. Whole-body vibration exercise (WBVE) has emerged as a new treatment method, but additional research is necessary to determine the optimal parameters of WBVE that would be beneficial for patients experiencing chronic low back pain (CLBP). This study aims to investigate the effects of two type of WBVE (constant vs progressive) on pain, disability, functional performance, and muscle activity in patients with NSCLBP. Thirty-two individuals diagnosed with chronic low back pain (CLBP) without any specific causes were enrolled and randomly assigned to one of two intervention groups: a constant/fixed protocol WBVE group or a progressive protocol WBVE group. Participants underwent WBVE sessions for around 30 min, thrice weekly over a period of 8 weeks. Primary outcomes assessed included pain intensity, functional disability, functional performance, and electromyographic activity of core musculature, measured at baseline and upon completion of the intervention period. Temporal changes of each outcome variable across different periods and between groups were measured with repeated measures 2×2 mixed ANOVA. Further, the paired t-test was performed to compare pre- and post-treatment values within each group. Significant improvements were observed in both the constant and progressive WBVE protocol groups. Pain intensity decreased by 64.2% (p<0.001) in the constant group and by 61.1% (p<0.001) in the progressive group. Functional disability decreased by 48.1% (p<0.001) in the constant group and by 53.3% (p<0.001) in the progressive group. Functional performance improved by 16.5% (p<0.001) in the constant group and by 16.9% (p<0.001) in the progressive group. Electromyography (EMG) demonstrated significant improvements across all measured variables except % maximum voluntary isometric contraction (%MVIC) of external obliques (EO) in both intervention groups with time (p<0.001). There was no statistically significant difference in the magnitude of improvement between the constant and progressive WBVE protocols (p>0.05), indicating both modalities' effectiveness in ameliorating CLBP symptoms and associated functional impairments. The study demonstrates that both progressive and constant WBVE protocols are equally effective in reducing pain and disability in NSCLBP patients. These findings support the inclusion of progressive WBVE in clinical practice, offering a flexible treatment option that can be tailored to individual patient needs, ensuring both tolerability and effectiveness. This contributes valuable evidence towards optimizing WBVE protocols for managing NSCLBP.

A Case of Open Zone Ⅰ Extensor Tendon Rupture Reconstructed by External Oblique Muscle Aponeurosis with Perifascial Areolar Tissue

A Case of Open Zone Ⅰ Extensor Tendon Rupture Reconstructed by External Oblique Muscle Aponeurosis with Perifascial Areolar Tissue

Prophylactic Sclerotherapy for Lymphatic Complications After Living Donor Renal Transplant: A Single-Center Experience.

Lymphocele formation after kidney transplant is a common complication that causes significant morbidity. In this study, we aimed to evaluate the safety and effectiveness of intraoperative prophylactic povidone-iodine sclerotherapy through the closed suction drain to prevent lymphocele after kidney transplant. In this retrospective comparative single-institution study, we compared patients who underwent intraoperative prophylactic povidone-iodine sclerotherapy through the closed suction drain (group A) with patients who did not receive sclerotherapy (group B). Patients were treated between September 2017 and July 2023. Atthe end of the kidney transplant surgery, after the closure of the external oblique muscle layer and before skin closure, 10 mL of 10% povidone-iodine in 40 mL of normal saline were instilled via the closed suction drain and dwelled in the cavity for 30 minutes. During the study period, 300 living-related donor kidney transplants were performed. Prophylactic povidone-iodine sclerotherapy was performed in 150 patients (50%).We noted a significantly lower incidence of lymphorrhea and lymphocele in group A. On postoperative days 1 and 5, we noted a significant reduction in drain output in group A (P < .001). One patient in group A and 5 patients in group B required ultrasonography-guideddrainage andpovidone-iodine sclerotherapy. No sclerotherapy-related complications were reported after a median follow-up of 16 months (range, 3-29 months). Intraoperative prophylactic povidoneiodine sclerotherapy appears to be an easy, safe, and effective procedure for preventing lymphatic complications after living donor kidney transplant.

Shear Wave Elastography for Assessment of Changes in Abdominal Soft Tissues after Lipoabdominoplasty.

The changes in the elasticity of the abdominal skin, subcutaneous tissues and muscles after lipoabdominoplasty are still unknown. The aim of this study was to provide an objective assessment of tissue elasticity after lipoabdominoplasty using ultrasound elastography. A total of 21 female patients (31-41 years old) who underwent lipoabdominoplasty from Oct 2019 to Mar 2022 were included in this retrospective study. The elastography values of the skin, subcutaneous tissues and abdominal muscles were obtained with the ultrasound shear wave elasticity imaging system pre-operation (Pre) and 6 months post-operation (Post) at four different points. Twenty-one female patients were included. The elasticity of the abdominal skin, subcutaneous tissues, rectus abdominis and external oblique abdominis significantly increased at 6 months post-operation. The improvements in abdominal soft tissue elasticity were not uniform across the examined points. Significant changes in the elasticity of the abdominal skin, subcutaneous tissues and muscles were observed after lipoabdominoplasty. Ultrasound elastographic assessment was objective and feasible for evaluating the effect of lipoabdominoplasty on abdominal soft tissue. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Determining the Association Between Insurance Type and Myofascial Release in Large Ventral Hernias

IntroductionAbdominal wall reconstruction (AWR) utilizes advanced myofascial releases to perform complex ventral hernia repair (VHR). The relationship between the performance of AWR and disparities in insurance type is unknown. MethodsThe Abdominal Core Health Quality Collaborative was queried for adults who had undergone an elective VHR between 2013 and 2020 with a hernia size ≥10 cm. Patients with missing insurance data were excluded. Comparison groups were divided by insurance type: favorable (private, Medicare, Veteran's Administration, Tricare) or unfavorable (Medicaid and self-pay). Propensity score matching compared the cumulative incidence of AWR between the favorable and unfavorable insurance comparison groups. ResultsIn total, 26,447 subjects met inclusion criteria. The majority (89%, n = 23,617) had favorable insurance, while (11%, n = 2830) had unfavorable insurance. After propensity score matching, 2821 patients with unfavorable insurance were matched to 7875 patients with favorable insurance. The rate of AWR with external oblique release or transversus abdominis release was significantly higher (23%, n = 655) among the unfavorable insurance group compared to those with favorable insurance (21%, n = 1651; P = 0.013). ConclusionsThis study provides evidence that patients with unfavorable insurance may undergo AWR with external oblique or transversus abdominis release at a greater rate than similar patients with favorable insurance. Understanding the mechanisms contributing to this difference and evaluating the financial implications of these trends represent important directions for future research in elective VHR.

The Association among Physical Activity, Sociodemographic, Trunk Muscles Thickness and Low Back Pain-Related Disability in Amateur Soccer Players: An Observational Study

Abstract Objective Although low back pain (LBP) is one of the most common musculoskeletal disorders, there is limited evidence assessing which factors contribute LBP severity in amateur athletes. We aimed to analyze relationships between sociodemographic, clinical, lifestyle and lumbar multifidus (LM) at L4 and L5 levels, rectus abdominis (RA), external and internal obliques (EO and IO) and transversus abdominis (TrA) muscles thickness assessed with ultrasound imaging (US) variables with lumbar disability in amateur athletes with LBP and lumbar disc herniation. Methods Eighty-two male amateur soccer athletes were analyzed. Demographic data, internal hip rotation, finger-floor distance, pain intensity, number of LBP episodes within the last year, metabolic equivalent of tasks for physical activity, sitting time, muscle thickness and disability caused by LBP were collected. Results Pain intensity showed significant associations with LBP recurrence, disability, sedentarism, trunk and hip flexibility, vigorous physical activity and TrA, EO and RA muscles thickness (p&lt;0.05). Similarly, disability was associated with number of LBP episodes, vigorous activity, sitting time, finger floor distance, and RA, EO and IO muscles thickness (p&lt;0.05). TrA thickness and internal hip rotation were not associated with lumbar disability (p&gt;0.05). Conclusion LBP intensity and pain-related disability were significantly associated with LBP episodes, vigorous activity, sitting time, finger floor distance, and thickness of abdominal muscles were associated with pain intensity and disability. However, lumbar multifidus thickness at rest, ankle dorsiflexion and walking time were not associated with clinical severity.

Chronic low back pain and muscle activity in women during the sit-to-stand task: A cross-sectional study

IntroductionThe ability to stand up and sit down is important. Due to the large number of repetitions of these activities during the day and the demand that the task requires, it is cited as painful in the presence of low back pain (LBP). Individuals with LBP present alterations in muscle activation, however, this statement needs to be verified during everyday situations like the sit-to-stand task (STST). Therefore, the objective was to evaluate the muscle recruitment of women with and without LBP during the STST. Methods35 women were evaluated, and allocated into the control group (CG n = 15) and the low back pain group (LBPG n = 20). The protocol consisted of clinical evaluation and the sit-to-stand task (STST). Electromyographic signals of the lumbar multifidus (LM), internal oblique (IO) and external oblique (EO), rectus abdominis (RA), and lumbar iliocostalis (LI) were carried out concomitantly with the STST. To verify normality, the Shapiro-Wilk test was used. For the characterization of the sample, the MANOVA test was chosen and the MANCOVA test was also chosen to compare the characteristics of the participants. ResultsRegarding the data analysis of the electromyographic signals, higher values were seen in the RA (moments 2 and 3) in the LBPG in the STST. ConclusionThe present study showed that women with chronic LBP present higher muscle activation of the rectus abdominis in the sit-to-stand task.

Effect of Exhaustive Exercise on Lumbopelvic-Hip Complex Stability, Muscle Activity, and Movement Patterns

This study aimed to evaluate the effect of exhaustive exercise on lumbopelvic-hip complex (LPHC) muscle activity, stability, and single-leg squat kinematics. Twenty-two healthy participants (12 females, 23.5 ± 3.1 years) were recruited. LPHC stability was measured by number of errors committed during a seated trunk control test (STCT). Surface electromyography recorded muscle activity of rectus abdominis (RA), external oblique, internal oblique (IO), erector spinae, and gluteus medius during the STCT and single-leg squat, and was normalized to peak activity during the task. Two-dimensional motion analysis quantified frontal and sagittal plane kinematics of the trunk, hip, and knee. Following exhaustive exercise, STCT performance worsened (number of errors: pre: 5.5 (interquartile range (IQR) = 1.4–9.0), post: 8.0 (IQR = 3.6–11.3), p = 0.026.), RA activity increased during the single-leg squat (pre: 42.1 (IQR = 33.6–48.5)%, post: 61.1 (IQR = 39.4–156.7 %, p =.004), and participants displayed less hip and knee flexion (hip: pre: 72.4 ± 22.1°; post: 66.2 ± 22.5°, p =.049; knee: pre: 72.4 ± 15.4°; post: 67.4 ± 18.2°, p =.005). Full-body exhaustive exercise negatively affected isolated LPHC stability and resulted in greater RA activity during the single-leg squat. Hip and knee flexion decreased during a single-leg squat after exhaustive exercise which could indicate decreased athletic performance, but changes in the quality of movement during other tasks should be further investigated.

Effectiveness of warm-up and dynamic balance training in preventing anterior cruciate ligament injuries in college gymnasts: a 3-year prospective study for one team.

The effect of trunk stability and dynamic balance warm-up exercises on physical functional improvement remains unelucidated. This study examined whether exercises could prevent anterior cruciate ligament (ACL) injury and improve trunk muscle activation and dynamic balance in gymnasts. This comparison study, involving gymnastics practice sessions, included 31 university gymnasts and was conducted in two periods: 1 year of observation followed by 2 years of intervention. Participants performed a trunk and dynamic balance warm-up exercise program during the intervention. The effect of exercise on the incidence of ACL injury was evaluated. In addition, the paired t-test was used to compare the Y-balance distance and the changes in muscle thickness associated with trunk muscle activation at rest and during plank. ACL injury risk during the intervention was significantly lower, with a relative risk of 0.23 (P=0.02, 95% CI: 0.06-0.88). Changes in muscle thickness with activation of the transversus abdominis (P<0.01, mean difference 4.1, 95% CI: 9.97-28.07, Cohen's d=0.52), internal oblique (P<0.01, mean difference 5.2, 95% CI: 9.72-21.55, Cohen's d=0.65), and external oblique (P<0.01, mean difference 5.5, 95% CI: 20.44-39.09, Cohen's d=0.71) muscles were significantly higher during the intervention. The Y-balance distance was also significantly greater in the posterior medial reach (P<0.01, mean difference 3.3, 95% CI: 1.56-6.26, Cohen's d=0.46) during the intervention. Exercise-based warm-up programs may decrease ACL injuries. It can improve physical functions, such as the rate of change in trunk muscle thickness and the posterior medial distance during Y balance.

Effects of loading positions on the activation of trunk and hip muscles during flywheel and dumbbell single-leg Romanian deadlift exercises

Objective: The study compared the activities of the surface electromyography (sEMG) of trunk and hip muscles during single-leg Romanian deadlift (SLRDL) exercises using a flywheel and dumbbell with different loading positions (ipsilateral and contralateral).Method: Twelve active male subjects with at least 2 years of strength training experience (age: 26.7 ± 3.3 years; weight: 73.9 ± 6.2 kg) participated in this study. sEMG in the percentage of maximum voluntary isometric contraction of four SLRDL exercises (ipsilateral and contralateral loading position for dumbbell and flywheel) in a randomized order for superior gluteus maximus (SGM), inferior gluteus maximus (IGM), gluteus medius (GM), biceps femoris (BF), erector spinae (ES), external oblique (EO), and adductor longus (AL) were measured. One-way repeated measure ANOVA with Bonferroni adjustment (statistical significance at 0.05) and the non-clinical magnitude-based decision with a standardized difference were performed for statistical analysis.Results: The overall results demonstrated a very high level of SGM (105.4%–168.6%) and BF (69.6%–122.4%) muscle activities. A significant moderate increase of sEMG signals in GM, IGM, and ES (dominant side) and a large increase in SGM activity during concentric action when the loading position of flywheel SLRDL was changed from ipsilateral to the contralateral side. No significant difference was observed between flywheel and dumbbell SLRDL exercises.Conclusion: Strength coaches may adopt dumbbell or flywheel SLRDL exercises using the contralateral loading position to simultaneously strengthen the hip extensors and trunk stabilizers effectively.

Contribution of Trunk Rotation and Abdominal Muscles to Sprint Kayak Performance.

Over the past two decades the importance of trunk contribution to sporting performance has been highlighted through the expanse of literature concerning core stability and strength. However, the role of trunk motion and the abdominal muscles are yet to be established during sprint kayak performance. The purpose of this study was to determine the associations among trunk rotation, kayak velocity, and abdominal muscle activity during on-water sprint kayaking. Eight international paddlers completed five 150 m sprint trials. During each trial peak muscle activation (peak root-mean-squared electromyogram) of the latissimus dorsi, rectus abdominus, external obliques and rectus femoris for ipsilateral (stroke side) and contralateral (opposite side) were recorded as the paddler passed through a 5-m calibrated volume, in conjunction with upper and lower trunk rotation and kayak velocity. Results indicated a significant strong negative relationship between lower trunk rotation and peak velocity (r = -0.684, p < 0.05). Furthermore, a significant strong positive relationship (p < 0.05) with mean velocity was identified for the contralateral rectus abdominus and multiple significant associations between the rectus femoris, rectus abdominus and external obliques during the paddle stroke. Findings indicate that limiting the rotation of the lower trunk will increase both the peak and the mean velocity, with the rectus abdominus, external oblique and rectus femoris combining to assist in this process. Training should therefore focus on developing the strength of these muscle groups to enhance performance.

Effect of verbal instructions on trunk muscle activity during volitional preemptive abdominal contraction

ObjectiveThis study investigated the effect of Verbal Instruction (VI) strategies on trunk muscle contraction among healthy subjects. The effect of three VI Abdominal Drawing-In Maneuver (ADIM) and two VI Abdominal Bracing Maneuver (ABM) strategies on left Internal (LIO) and External Oblique (LEO) and bilateral superficial Multifidi (sMf) activation was examined. DesignWithin-subjects, repeated measure design. MethodsSurface EMG (sEMG) measured LIO, LEO, and sMf activity in 28 subjects (mean age 23.5 ± 5.5 years). Testing included five supine hook-lying and five quiet standing conditions. ResultsOne-way ANOVAs demonstrated no significant main effect for ADIM or ABM in supine or standing (p > .05). Muscle activation amplitudes during VPAC conditions demonstrated higher mean values for standing versus supine (p < .05) except for two conditions involving LEO. Friedman Tests for dominant strategy demonstrated a significant main effect for ADIM-VI and ABM-VI strategies. Post-hoc testing generally showed the dominant strategy to be significantly higher versus others. ConclusionNo single preferred VI cue for ADIM or ABM was observed. Each subject's dominant strategy dictated the most suitable VI. Standing was preferred for LIO and sMf activation, whereas position did not change LEO activation. Non-significant correlations between all muscle pairings during all ADIM and ABM strategies were observed. These findings may suggest the need for healthcare providers who understand the intricacies of trunk stability to teach and monitor VPAC with either ADIM or ABM options.

Significant relationship between musculoaponeurotic attachment of the abdominal and thigh adductor muscles to the pubis: implications for the diagnosis of groin pain.

Groin pain is prevalent in orthopedic and sports medicine, causing reduced mobility and limiting sports activity. To effectively manage groin pain, understanding the detailed anatomy of supporting muscles is crucial. This study aimed to investigate the musculoaponeurotic attachments on the pubis and the relationship among intramuscular aponeuroses of abdominal and thigh adductor musculatures. Macroscopic analyses were performed in 10 pelvic halves. The bone morphology of the pubis was assessed in two pelvic halves using microcomputed tomography. Histological investigations were conducted in two pelvic halves. The external oblique aponeurosis extended to the adductor longus aponeurosis, forming conjoined aponeurosis, which attached to a small impression distal to the pubic crest. The gracilis aponeurosis merges with the adductor brevis aponeurosis and is attached to the proximal part of the inferior pubic ramus. The rectus abdominis and pyramidalis aponeuroses were attached to the pubic crest and intermingled with the gracilis-adductor brevis aponeurosis, forming bilateral conjoined aponeurosis, which attached to a broad area covering the anteroinferior surface of the pubis. Histologically, these two areas of conjoined aponeuroses were attached to the pubis via the fibrocartilage enthesis. Microcomputed tomography revealed two distinctive bone morphologies, a small impression and an elongated osseous prominence on pubis, corresponded to the two areas of conjoined aponeuroses. This study demonstrated close relationships between the aponeurotic attachment of the external oblique and adductor longus, and between the rectus abdominis, pyramidalis, gracilis, and adductor brevis. The findings of aponeurotic complexes would aid in diagnostic and surgical approaches for athletic groin pain.

Age influences the specific force and fatigability of the external abdominal obliques but not pectoralis major muscles

In the elderly, airway infections are associated with impaired airway defense behaviors, leading to an increased risk of airway infection. The muscles of the chest and abdominal wall are essential for performing effective airway defense manoeuvres, however, very little is known about their function in aging. Here in the 6- and 24-months old Fischer 344 rat model of aging, we assess the contractility and fatigability of chest (the pectoralis major muscle) and abdominal wall (external abdominal oblique) muscles. We assessed muscle function using an ex vivo approach, measuring isometric specific forces normalised to muscle CSA, via a platinum plate field stimulations at a range of frequencies (5–150 Hz) for 1 s. Surprisingly, we did not observe any effect of age on the specific force and fatigue properties of the pectoral muscle. However, in 24-months old rats, EAO specific force was reduced by ∼32 %. These finding suggest that not all respiratory muscles are equally vulnerable to age-associated weakness.