Internal Muscle Research Articles

Lateral internal sphincterotomy under local and spinal anaesthesia for chronic anal fissure: A randomised control trial

Introduction Anal fissure is described as a linear defect, or laceration, in the anoderm, located between the dentate line and the anal verge. An acute fissure is a simple laceration, whereas a chronic anal fissure is an ulceration with built-up scarred edges and exposed internal anal sphincter muscle fibers at its base. Additional findings may include a perianal skin tag at the external margin of the fissure and a hypertrophied papilla at the dentate.

Dynamic biomechanical characterization of colon tissue according to anatomical factors

IntroductionThe aim of this study was to determine the mechanical response of colonic specimens retrieved from the entire human colon and placed under dynamic solicitation until the tissue ruptured. Material and methodsSpecimens were taken from 20 refrigerated cadavers from different locations of the colonic frame (ascending, transverse, descending and sigmoid colon) in two different directions (longitudinal and circumferential), with or without muscle strips (taenia coli). A total of 120 specimens were subjected to tensile tests, after preconditioning, at the speed of 1m/s. ResultsHigh-speed video analysis showed a bilayer injury process with an initial rupture of the serosa / external muscular layer followed by a second rupture of the inner layer consisting of the internal muscle / submucosa / mucosa.The mechanical response was biphasic, with a first point of initial damage followed by a complete rupture. The levels of stress and strain at the failure site were statistically greater in terms of circumferential stress (respectively 69±22% and 1.02±0.50MPa) than for longitudinal stress (respectively 55±32% and 0.70±0.34MPa). The difference between longitudinal and circumferential stress was not statistically significant (3.17±2.05MPa for longitudinal stress and 3.15±1.73MPa for circumferential stress). The location on colic frame significantly modified the mechanical response both longitudinally and circumferentially, whereas longitudinal taenia coli showed no mechanical influence. ConclusionThe mechanical response of the colon specimen under dynamic uniaxial solicitation showed a bilayer and biphasic injury process depending on the direction of solicitation and colic localization. Furthermore these results could be integrated into a numeric model reproducing abdominal trauma to better understand and prevent intestinal injuries.

A new T staging system for nasopharyngeal carcinoma based on magnetic resonance imaging and intensity-modulated radiotherapy

Objective To establish a new T staging system for nasopharyngeal carcinoma (NPC) based on magnetic resonances imaging (MRI) and intensity-modulated radiotherapy (IMRT). Methods A retrospective analysis was performed on the clinical data of 608 patients who were newly diagnosed with non-metastatic NPC by MRI and treated with IMRT in our hospital from 2008 to 2010. All patients were staged according to the 7th edition of the UICC/AJCC staging system for NPC. The survival rates were calculated using the Kaplan-Meier method and analyzed using the log-rank test. The Cox regression model was used for multivariate analyses. To deal with the deficiency in the current UICC/AJCC staging system, a new T staging system for NPC was established and systematically evaluated. Results The 5-year follow-up rate was 94.5%. The 5-year overall survival (OS), disease-free survival, local relapse-free survival (LRFS), and distant metastasis-free survival rates were 81.5%, 80.1%, 86.0%, and 81.1%, respectively. The univariate and multivariate analyses showed that the anatomic structures of nasopharynx, parapharyngeal space, and skull base were influencing factors for the OS rate (P=0.000-0.045). New T staging criteria were proposed based on the risk differences and survival curves: stage T1: invasion of the nasopharynx, parapharyngeal space, oropharynx, nasal cavity, skull base, and internal pterygoid muscle; stage T2: invasion of the external pterygoid muscle, paranasal sinus, intracalvarium, infratemporal fossa, and cranial nerves. The proposed T staging system achieved a good separation in both OS and LRFS curves. Conclusions The proposed new T staging system gives an objective prognostic prediction in patients with NPC, which provides an exploratory attempt toward a new clinical staging system for NPC. Key words: Nasopharyngeal neoplasms/intensity-modulated radiotherapy; Magnetic resonances imaging; Hazard discrimination; T staging system; Prognosis

Age-related alterations in female obturator internus muscle.

Pelvic floor muscle rehabilitation is a widely utilized, but often challenging therapy for pelvic floor disorders, which are prevalent in older women. Regimens involving the use of appendicular muscles, such as the obturator internus (OI), have been developed for strengthening of the levator ani muscle (LAM). However, changes that lead to potential dysfunction of these alternative targets in older women are not well known. We hypothesized that aging negatively impacts OI architecture, the main determinant of muscle function, and intramuscular extracellular matrix (ECM), paralleling age-related alterations in LAM. OI and LAM were procured from three groups of female cadaveric donors (five per group): younger (20 - 40years), middle-aged (41 - 60years), and older (≥60years). Architectural predictors of the excursional (fiber length, L f), force-generating (physiological cross-sectional area, PCSA) and sarcomere length (L s) capacity of the muscles, and ECM collagen content (measure of fibrosis) were determined using validated methods. The data were analyzed using one-way ANOVA and Tukey's post-hoc test with a significance level of 0.05, and linear regression. The mean ages of the donors in the three groups were 31.2 ± 2.3years, 47.6 ± 1.2years, and 74.6 ± 4.2years (P < 0.005). The groups did not differ with respect to parity or body mass index (P > 0.5). OI L f and L s were not affected by aging. Age >60years was associated with a substantial decrease in OI PCSA and increased collagen content (P < 0.05). Reductions in OI and LAM force-generating capacities with age were highly correlated (r 2 = 0.9). Our findings of age-related decreases in predicted OI force production and fibrosis suggest that these alterations should be taken into consideration, when designing pelvic floor fitness programs for older women.

Fetal development of the pulley for muscle insertion tendons: A review and new findings related to the tensor tympani tendon

The existence of hard tissue pulleys that act to change the direction of a muscle insertion tendon is well known in the human body. These include (1) the trochlea for the extraocular obliquus superior muscle, (2) the pterygoid hamulus for the tensor veli palatini muscle, (3) the deep sulcus on the plantar aspect of the cuboid bone for the peroneus longus tendon, (4) the lesser sciatic notch for the obturator internus muscle, and (5) the bony trochleariformis process for the tensor tympani muscle tendon. In addition, (6) the stapedius muscle tendon shows a lesser or greater angulation at the pyramidal eminence of the temporal bone. Our recent studies have shown that the development of pulleys Nos. 1 and 2 can be explained by a change in the topographical relationship between the pulley and the tendon, that of pulley No. 3 by the rapidly growing calcaneus pushing the tendon, and that of pulley No. 4 by migration of the insertion along the sciatic nerve and gluteus medius tendon. Therefore, in Nos. 1–4, an initially direct tendon curves secondarily and obtains an attachment to the pulley. In case No. 6, the terminal part of the stapedius tendon originates secondarily from the interzone mesenchymal tissue of the incudostapedial joint. In the case of pulley No. 5, we newly demonstrated that its initial phase of development was similar to No. 6, but the tensor tympani tendon achieved a right-angled turn under guidance by a specific fibrous tissue and it migrated along the growing malleus manubrium.

Single-Incision Mini-Slings: Obturator Complex Pull-Out-Force Measurements

Aim: To evaluate the different pull-out-force out of the obturator membrane and the obturator internus muscle of 2 mini-sling systems for stress urinary incontinence (SUI) treatment. Material and Methods: In a prospective study, the pull-out-force measurements were performed on 8 female cadaver pelvises, both on the obturator membrane and internal muscle, using the force measurement device PCE-FM50 (PCE Instruments). Tested were the hooks of 2 on the market available mini-sling kits (MiniArc by American Medical System; Ajust by BARD Inc.). Connected to the force measurement device, the hooks were placed into the obturator membrane and the obturator internus muscle. Mean value and SD were documented. Results: On the complete obturator complex, Ajust showed a significantly higher pull-out-force (2,561.75 ± 638.8 g) than did the MiniArc (1,780.69 ± 442.3 g), p = 0.025. No significant differences were performed on the obturator membrane. Conclusions: The Ajust mini-sling hook is, given the objective results, more stably attached to the obturator complex than the MiniArc. Yet, both systems are sufficiently attachable to the evaluated anatomic structures, fulfilling the needed requirements for their use in the treatment of SUI.

Hip muscle strength and static balance in patients with snapping hip syndrome – a pilot study

Abstract Introduction: Snapping hip syndrome (SHS) occurs in 5-10% of the global population. A back and forth skip of the tendon of the dysfunctional muscle across the osseous prominence is the most common symptom of this condition. Mainly young generation suffers from SHS. Depending on the structures that cause an audible snap, snapping hip syndrome may be classified into intra-articular and extra-articular types. The main aim of the research was to assess the strength of the major hip muscles and static balance in patients with snapping hip syndrome. Material and methods: The research was carried out on 10 untrained females and 10 untrained males with extra-articular snapping hip syndrome. An average age was approximately 25 years. The research was conducted with the use of interview questionnaire, clinical examination, balance assessment on the JBA Staniak 4P dynamometric platform and measurements of the hip muscle strength on the JBA Staniak SPB2 set. Results: Patients with SHS manifested an increased tension in iliotibial band, while significant weakening of internal and external rotator muscle strength was noted in women and significant weakening of external rotator muscle strength was observed in men. No correlations between hip muscles strength and stabilographic test results in patients with snapping hip syndrome were found. Conclusions: Individuals with SHS and healthy persons demonstrate similar balance levels. The treatment of snapping hip syndrome should include: 1) restoring internal rotator muscle strength in women, 2) restoring external rotator muscle strength both in women and in men, as well as 3) restoring iliotibial band flexibility.

Green tea extract catechin improves internal cardiac muscle relaxation in RCM mice.

BackgroundDiastolic dysfunction refers to an impaired relaxation and an abnormality in a heart’s filling during diastole while left ventricular systolic function is preserved. Diastolic dysfunction is commonly observed in patients with primary hypertension, diabetes and cardiomyopathies such as hypertrophic cardiomyopathy or restrictive cardiomyopathy. We have generated a restrictive cardiomyopathy (RCM) mouse model with troponin mutations in the heart to mimic the human RCM patients carrying the same mutations.ResultsIn the present study, we have investigated the ventricular muscle internal dynamics and pressure developed during systole and diastole by inserting a micro-catheter into the left ventricle of the RCM mice with or without treatment of desensitizer green tea extracts catechins. Our results demonstrate that green tea catechin is able to correct diastolic dysfunction in RCM mainly by improving ventricular compliance and reducing the internal muscle rigidity caused by myofibril hypersensitivity to Ca2+.ConclusionGreen tea extract catechin is effective in correcting diastolic dysfunction and improving ventricular muscle intrinsic compliance in RCM caused by troponin mutations.

Muscle system in rediae and daughter sporocysts of several digeneans

Morphological studies on digenetic trematodes are quite numerous, but the large majority of researchers deal with the hermaphroditic generation (cercariae, metacercariae, adults). Parthenitae (miracidia, sporocysts, rediae), although they constitute a significant part of a digeneans’ life cycle, attract much less attention. The sparse literature concerning the musculature of parthenitae indicates that it differs in many respects from that of digenean hermaphroditic generation and many other flatworms. We have tried to fill the knowledge gap on digenean muscle systems by focusing on daughter parthenitae (three species with rediae and two with daughter sporocysts). The study was performed using TRITC-phalloidin labeling and confocal microscopy and was aimed at both describing general trends and comparing different morphotypes. The basic body-wall muscle layers were confirmed to be composed of circular and longitudinal muscle fibers. Circular fibers form quite a uniform layer, and longitudinal fibers are typically joined into bundles. The density of muscle layers varies widely among studied species, and the possible causes of this variation are discussed. The internal muscle fibers and bundles are present in all studied species, being most prominent in the anterior region. The brood chamber and birth pore channel often have a muscular lining. The rediae pharynx has a typical set of muscle elements, mostly coinciding with one in the pharynx of the hermaphroditic generation. Taken together, our findings suggest that data on the musculature of daughter parthenitae are important from an evolutionary perspective.

Simultaneous optimisation of earwig hindwings for flight and folding.

ABSTRACTEarwig wings are highly foldable structures that lack internal muscles. The behaviour and shape changes of the wings during flight are yet unknown. We assume that they meet a great structural challenge to control the occurring deformations and prevent the wing from collapsing. At the folding structures especially, the wing could easily yield to the pressure. Detailed microscopy studies reveal adaptions in the structure and material which are not relevant for folding purposes. The wing is parted into two structurally different areas with, for example, a different trend or stiffness of the wing veins. The storage of stiff or more flexible material shows critical areas which undergo great changes or stress during flight. We verified this with high-speed video recordings. These reveal the extent of the occurring deformations and their locations, and support our assumptions. The video recordings reveal a dynamical change of a concave flexion line. In the static unfolded state, this flexion line blocks a folding line, so that the wing stays unfolded. However, during flight it extends and blocks a second critical folding line and prevents the wing from collapsing. With these results, more insight in passive wing control, especially within high foldable structures, is gained.

The effects of a passive exoskeleton on muscle activity, discomfort and endurance time in forward bending work

Exoskeletons may form a new strategy to reduce the risk of developing low back pain in stressful jobs. In the present study we examined the potential of a so-called passive exoskeleton on muscle activity, discomfort and endurance time in prolonged forward-bended working postures.Eighteen subjects performed two tasks: a simulated assembly task with the trunk in a forward-bended position and static holding of the same trunk position without further activity. We measured the electromyography for muscles in the back, abdomen and legs. We also measured the perceived local discomfort. In the static holding task we determined the endurance, defined as the time that people could continue without passing a specified discomfort threshold.In the assembly task we found lower muscle activity (by 35–38%) and lower discomfort in the low back when wearing the exoskeleton. Additionally, the hip extensor activity was reduced. The exoskeleton led to more discomfort in the chest region. In the task of static holding, we observed that exoskeleton use led to an increase in endurance time from 3.2 to 9.7 min, on average.The results illustrate the good potential of this passive exoskeleton to reduce the internal muscle forces and (reactive) spinal forces in the lumbar region. However, the adoption of an over-extended knee position might be, among others, one of the concerns when using the exoskeleton.

Management of stress urinary incontinence

Female stress urinary incontinence (SUI) is a common condition with significant impact on a woman’s quality of life. The prevalence of SUI is about 50%. Previously, the majority of incontinence procedures were performed via an abdominal approach (Burch colposuspension). The tension-free procedures, with a synthetic tape material, have replaced almost completely the previous surgeries and is nowadays considered the gold standard option for surgical treatment of female SUI. A wide spectrum of tape-based surgical procedures and devices are currently available. Today, Burch colposuspension has a role in patients undergoing abdominal pelvic organ prolapse (POP) repair as a concomitant procedure in those patients with urethral hypermobility or those with contraindication to mid-urethral slings (MUS) placement. The objective success rate reported of this procedure ranges between 49% and 88%. Mid-urethral synthetic slings represent the most common procedures for SUI in North America and Europe. Cure rate of retropubic MUS approaches 86% with a satisfaction rate of about 75%. For transobturator tape MUS the objective success rate at 12 months is 87% and the satisfaction rate is 85%. Single incision mini-slings (SIMS) were introduced in 2003 and they have a different anchoring mechanism, located at the two extremities, that allows the stabilization of the tape in the obturator internal muscle or deeper in the obturator channel trough a single vaginal incision. Reported objective cure rate is 78% and satisfaction rate is 82%. According to the most recent EAU guidelines about incontinence and the UK National Institute for Healthcare and Clinical Excellence (NICE), the surgeon must be able to offer alternative surgical treatments and have the knowledge of efficacy and safety of these approaches at counseling of the patient. The objective cure rate is rather similar among the different types and routs of mid-urethral slings and the difference vs. Burch colposuspension seems to disappear at 5 years follow-up, when effectiveness is comparable. There is no significant difference in erosion rates between transobturator and retropubic approaches among mid-urethral tapes, but they are lower when compared to SIMS. The injury rate of nearby organs is quite low for all types of approaches, except for retropubic slings.

TVT ABBREVO: cadaveric study of tape position in foramen obturatum and adductor region.

The aim of the study was to describe fixation of the TVT ABBREVO and establish whether the tape penetrates through obturator muscles and membrane (obturator complex) into the adductor region and, if so, how far it penetrates. Eight formalin-embalmed female cadavers were used to simulate TVT ABBREVO surgery (totalling 16 insertions). Following tape insertion, dissection was performed and ends of the tape were identified. In cases of penetration, the length of tape penetrating into the adductor region was measured. Of the 16 cases, the tape ended in the obturator membrane in eight, in the internal obturator muscle in one, and penetrated through the obturator membrane into the external obturator muscle in five, where it remained. In two cases, it penetrated through the obturator internus muscle, obturator membrane and obturator externus muscle into the group of thigh adductors; one penetration was by 3mm and the second by 10mm. No contact with the obturator nerve or its branches was noted in any case. No TVT contact with the obturator nerve was noted; tape penetrated into the adductor region in two of the 16 cases.

Sister Mary Joseph nodule.

Learning points for clinicians Sister Mary Joseph nodule can be as the first signal of advanced intra-abdominal malignancy. It could be easily mistaken for omphalitis, cyst, hernia and skin disease, which leads to the delayed finding of primary tumors. Umbilical nodule in an adult patient should be considered as metastasis until proven otherwise. A 53-year-old man with known stage IV bladder cancer, diagnosed in 2011, was admitted to the hospital for progressive fatigue and diffuse abdominal pain. In 2011, abdominal CT scan revealed a tumor (5.9 × 6.4 cm) in the bladder with muscle-layer invasion, abutting the right internus muscle, and right …

The effects of transcutaneous neuromuscular electrical stimulation on the activation of deep lumbar stabilizing muscles of patients with lumbar degenerative kyphosis.

[Purpose] To investigate the effectiveness of three different neuromuscular electrical stimulation (NMES) protocols for the deep lumbar stabilizing muscles of patients with lumbar degenerative kyphosis (LDK). [Subjects and Methods] Twenty patients with LDK were recruited. Three stimulation protocols were investigated: stimulation of the abdominal muscles (protocol A); stimulation of the lumbar muscles (protocol B); and simultaneous stimulation of the abdominal and lumbar muscles (protocol A+B). Images of the obliquus externus (OE), obliquus internus (OI), transversus abdominis (TrA), and lumbar multifidus (LM) muscles were captured by real-time ultrasound imaging (RUSI). [Results] The thickness of LM was significantly greater during stimulation than at rest for all three protocols. Thicknesses of the abdominal muscles (TrA, OI, and OE) were significantly greater during stimulation than at rest for protocols A and A+B. Thickness increases in LM were significantly greater during protocols B and A+B, but not during protocol A. Thickness increases in the abdominal muscles (TrA, OI, and OE) were significantly greater during protocols A and A+B, but not during protocol B. [Conclusion] NMES can significantly activate the deep lumbar stabilizing muscles of patients with LDK. Protocol A+B of NMES is recommended to aid postural correction and low back pain (LBP) in patients with LDK.

Isokinetic Performance of Shoulder External and Internal Rotators in Adolescent Male Volleyball Athletes

Title: Isokinetic performance of shoulder external and internal rotators in young male volleyball athletes. Background: Volleyball is a sport characterized by short, intensive and explosive actions. In the performance of these repetitive movements, the shoulder joint receives the largest load. Therefore, a detailed assessment of biomechanics and muscle performance is fundamental in the evaluation, treatment and in prevention of shoulder injuries in volleyball athletes. Methods and Findings: Information from a database concerning the isokinetic evaluation of the shoulder’s external and internal rotator muscles at the 60°/s and 180°/s angular velocities from 20 male volleyball athletes under 17 years of age was assessed. At a velocity of 60°/s the average values for internal rotators on the non-dominant limb were significantly smaller than those of the dominant limb, and at a velocity of 180°/s both the internal and external rotators average values for the non-dominant limb were significantly smaller than those for the dominant limb. For the external-internal rotator ratio analyses, there was no significant difference between the limbs. Conclusions: In conclusion, the unilateral demands during typical movements in volleyball resulted in higher peak torque values for the dominant limb in comparison to that of the non-dominant limb. For the external-internal rotators, no relevant differences were found between limbs, and the average values were within the parameters of normality.

Correction of breast asymmetry and minor ptosis with internal mastopexy and muscle splitting biplane breast augmentation

Correction of breast asymmetry and minor ptosis with internal mastopexy and muscle splitting biplane breast augmentation

Successful Surgical Management of Recurrent Perineal Hernia Using Colopexy and Cystopexy in a Dog

The aim of this report is to describe the successful management of long standing and recurrent perineal hernia with transposition of internal obturator muscles, colopexy, cystopexy and castration in a non- descript dog.

The Role of the Obturator Internus Muscle in Pelvic Floor Function

The Role of the Obturator Internus Muscle in Pelvic Floor Function

Musculoskeletal Proportionality, Biomechanical Considerations, and Their Contribution to Movement in Adults and Children.

The musculoskeletal system grows greatly throughout maturation. When trying to explain differences in strength, power and movement patterns between adults and children many pediatric exercise scientists will assume that this growth is proportional in all dimensions and structures. This article examines the evidence underpinning these assumptions, and considers how changes in fascicle, muscle, tendon and joint proportions may contribute to maturation-induced changes in physical performance. There are only a small number of studies to draw upon, but they consistently indicate that 1) growth changes the functional design of muscles, so that they become better at producing large forces at slow speeds but less able to achieve large length changes or high velocities; 2) the skeleton appears to grow somewhat proportionally before puberty, but this changes throughout adolescence, meaning the moment arm about which the muscle acts does not remain proportional to muscle length or the external moment arm about which joint work acts on the external world. In combination these results show that external measures of whole body or joint performance do not reflect the actual internal muscle function similarly in children and adults. Since our purpose should be to explain and not just describe maturation-induced changes in performance, greater efforts are needed to understand the internal "engine" driving our movement. This necessitates more detailed, longitudinal and dynamically loaded studies of the structure and function of the muscles and their interaction with the skeleton throughout maturation.