Utilização do tendão do músculo palmar longo em procedimentos cirúrgicos: estudo em cadáveres Use of the tendon of the palmaris longus muscle in surgical procedures: study on cadavers

Directory of Open Access Journals (Sweden)

Luiz Carlos Angelini Júnior

2012-01-01

Full Text Available OBJETIVO: Demonstrar que o tendão do músculo palmar longo pode ser estimado em relação ao seu comprimento e largura antes de usá-lo como enxerto em procedimento cirúrgico. MÉTODOS: Foram examinados 60 antebraços de 30 cadáveres de etnia negra; mensurou-se o comprimento e a largura do tendão do músculo palmar longo e comparou-se com o comprimento do antebraço. RESULTADOS: Foi constatada a ausência unilateral direita em dois cadáveres do sexo feminino. As médias do comprimento e da largura foram respectivamente 11,9 mais ou menos 15,2mm e 4,1 + 1,5mm. A média total do comprimento do antebraço foi de 275.4mm mais ou menos 17,9mm. CONCLUSÃO: Há uma relação significativa entre o comprimento do tendão e o comprimento do antebraço; assim poder-se-á avaliar o tamanho do tendão do músculo palmar longo quando for necessário usá-lo para enxertos. Nível de Evidências IV, Série de casos.OBJECTIVE: Demonstrate that the tendon of palmar long can be estimated in relation to its length and width before using it as a graft in surgical procedure. METHODS: There were examined 60 forearms of 30 corpses of black ethnicity; measure the length and width of the tendon of the palmaris longus muscle and compared the length of the forearm. RESULTS: There are notes their absence unilateral right in two female corpses. The medium length and width were more or less respectively 11.9, 15.2 mm and 4.1 + 1.5 mm. The total average forearm length of 275.4 was more or less 17.9 mm. CONCLUSION: There is a significant relationship between the length of the tendon and the length of the forearm; so we can evaluate the size of the tendon of the palmaris longus muscle when it is necessary to use it for grafts. Levels of Evidence IV, Case series.

Ultrastructural muscle and neuro-muscular junction alterations in polymyositis

Directory of Open Access Journals (Sweden)

L. L. Babakova

2012-01-01

Full Text Available Ultrastructural analysis of 7 biopsies from m.palmaris longus and m.deltoideus in patients with confirmed polymyositis revealed alterationand degeneration of muscle fibers and anomalies of neuro-muscular junction (NMJ. The NMJ abnormalities and following denervation ofmuscle fibers in polymyositis start with subsynaptic damages. The occurance of regeneration features in muscle fibers at any stage is characteristic for PM.

Bilateral Tensor Fasciae Suralis Muscles in a Cadaver with Unilateral Accessory Flexor Digitorum Longus Muscle

Directory of Open Access Journals (Sweden)

Logan S. W. Bale

2017-01-01

Full Text Available Muscle variants are routinely encountered in the dissection laboratory and in clinical practice and therefore anatomists and clinicians need to be aware of their existence. Here we describe two different accessory muscles identified while performing educational dissection of a 51-year-old male cadaver. Tensor fasciae suralis, a rare muscle variant, was identified bilaterally and accessory flexor digitorum longus, a more common muscle variant, was present unilaterally. Tensor fasciae suralis and accessory flexor digitorum longus are clinically relevant muscle variants. To our knowledge, the coexistence of tensor fasciae suralis and accessory flexor digitorum longus in the same individual has not been reported in either cadaveric or imaging studies.

Intermuscular interaction via myofascial force transmission: Effects of tibialis anterior and extensor digitorum longus length on force transmission from rat extensor digitorum longus muscle

NARCIS (Netherlands)

Maas, Huub; Baan, Guus C.; Huijing, P.A.J.B.M.

2001-01-01

Force transmission in rat anterior crural compartment, containing tibialis anterior (TA), extensor hallucis longus (EHL) and extensor digitorum longus (EDL) muscles, was investigated. These muscles together with the muscles of the peroneal compartment were excited maximally. Force was measured at

Myostatin dysfunction impairs force generation in extensor digitorum longus muscle and increases exercise-induced protein efflux from extensor digitorum longus and soleus muscles.

Science.gov (United States)

Baltusnikas, Juozas; Kilikevicius, Audrius; Venckunas, Tomas; Fokin, Andrej; Bünger, Lutz; Lionikas, Arimantas; Ratkevicius, Aivaras

2015-08-01

Myostatin dysfunction promotes muscle hypertrophy, which can complicate assessment of muscle properties. We examined force generating capacity and creatine kinase (CK) efflux from skeletal muscles of young mice before they reach adult body and muscle size. Isolated soleus (SOL) and extensor digitorum longus (EDL) muscles of Berlin high (BEH) mice with dysfunctional myostatin, i.e., homozygous for inactivating myostatin mutation, and with a wild-type myostatin (BEH+/+) were studied. The muscles of BEH mice showed faster (P myostatin dysfunction leads to impairment in muscle force generating capacity in EDL and increases susceptibility of SOL and EDL to protein loss after exercise.

Evaluation of the neuromuscular compartments in the peroneus longus muscle through electrical stimulation and accelerometry

Directory of Open Access Journals (Sweden)

Guillermo A. Mendez

2013-10-01

Full Text Available BACKGROUND: Muscles are innervated exclusively by a nerve branch and possess definite actions. However, mammalian skeletal muscles, such as the trapezius, the medial gastrocnemius, and the peroneus longus, are compartmentalized. In the peroneus longus muscle, multiple motor points, which innervate individual neuromuscular compartments (NMC, the superior (S-NMC, anteroinferior (AI-NMC, and posteroinferior (PI-NMC, have been described. The contribution of each neuromuscular compartment to the final action of the muscle is fundamental for the rehabilitation of patients afflicted by neurological and muscle dysfunctions. Interventions are often based on electrical principles that take advantage of the physiological characteristics of muscles and nerves to generate therapeutic effects. OBJECTIVE: To compare the effects of stimulating the different neuromuscular compartments (NMCs of the peroneus longus muscle on the motor threshold (MT and acceleration of the foot. METHOD: This is a cross-sectional study comprising 37 subjects. The three NMCs of the peroneus longus muscle were stimulated, and the acceleration of the foot and the motor threshold of each NMC were evaluated. A repeated measures analysis of variance with Bonferroni corrections of two intra-subjects factors was performed. RESULTS: The stimulation of the different NMCs did not result in any differences in MT (F=2.635, P=0.079. There were significant differences between the axes of acceleration caused by the stimulation of the different NMCs (F=56,233; P=0.000. The stimulation of the posteroinferior compartment resulted in the greatest acceleration in the X-axis (mean 0.614; standard deviation 0.253. CONCLUSIONS: The posteroinferior compartment primarily contributes to the eversion movement of the foot. NMCs have specific functional roles that contribute to the actions of the muscles to which they belong.

Occasional head of flexor pollicis longus muscle: a study of its morphology and clinical significance.

Directory of Open Access Journals (Sweden)

Hemmady M

1993-01-01

Full Text Available A cadaveric dissection study of 54 upper extremities to determine the incidence of occurrence, morphology and relations of the occasional head of the flexor pollicis longus muscle is presented. The occasional head of the flexor pollicis longus muscle was found to be present more frequently (66.66% than absent. It mainly arose from the medical epicondyle of the humerus (55.55% and the medial border of the coronoid process of the ulna (16.66%. It was found to be in close association with the median nerve (anteriorly and the anterior interosseous nerve (posteriorly. The clinical implications of these findings are discussed viz. entrapment neuropathies of the median and anterior interosseous nerves, cicatricial contraction of the occasional head leading to flexion deformity of the thumb and the likely necessity to lengthen/release the occasional head in spastic paralysis of the flexor pollicis longus muscle.

Anomalous bilateral contribution of extensor pollicis longus and muscle fusion of the first compartment of the wrist

Directory of Open Access Journals (Sweden)

Rodrigo César Rosa

2016-04-01

Full Text Available Knowledge of the anatomical variations of the muscles of the first dorsal compartments of the wrist is clinically relevant to De Quervain's tenosynovitis and to reconstructive surgeries. In the literature, there are many reports of the presence of multiple insertion tendons in the first dorsal compartment of the wrist, but few reports describe occurrences of fusion and muscle contributions. This case report describes an anomalous bilateral contribution of the extensor pollicis longus. This anomalous contribution was found through a slender auxiliary tendon that crossed laterally under the extensor retinaculum, entered the first dorsal compartment of the wrist and merged with the tendon of the extensor pollicis brevis muscle. In the same cadaver in which this contribution was present, there was atypical muscle fusion of the abductor pollicis longus muscle and extensor pollicis brevis muscle. In conclusion, anomalous bilateral contribution of the extensor pollicis longus muscle and atypical muscle fusion, concomitant with a variant insertion pattern, are the highlight of this case report. Furthermore, it is concluded that additional tendons may be effectively used in reconstructive surgeries, but that there is a need for knowledge of the possible numerical and positional variations of these tendons, with a view to making more effective surgical plans.

Myofascial force transmission causes interaction between adjacent muscles and connective tissue: Effects of blunt dissection and compartmental fasciotomy on length force characteristics of rat extensor digitorum longus muscle

NARCIS (Netherlands)

Huijing, P.A.J.B.M.; Baan, G.C.

2001-01-01

Muscles within the anterior tibial compartment (extensor digitorum longus: EDL. tibialis anterior: TA, and extensor hallucis longus muscles: EHL) and within the peroneal compartment were excited simultaneously and maximally. The ankle joint was fixed kept at 90°. For EDL length force characteristics

Surgical Anatomy of the Longus Colli Muscle and Uncinate Process in the Cervical Spine

Science.gov (United States)

Moon, Seong-Hwan; Kim, Tae-Hwan; Oh, Jae Keun; Kim, Hyung Joon; Park, Kun-Tae; Riew, K. Daniel

2016-01-01

Purpose There have been a few previous reports regarding the distances between the medial borders of the longus colli to expose the disc space. However, to our knowledge, there are no reports concerning longus colli dissection to expose the uncinate processes. This study was undertaken to assess the surgical relationship between the longus colli muscle and the uncinate process in the cervical spine. Materials and Methods This study included 120 Korean patients randomly selected from 333 who had cervical spine MRIs and CTs from January 2003 to October 2013. They consisted of 60 males and 60 females. Each group was subdivided into six groups by age from 20 to 70 years or more. We measured three parameters on MRIs from C3 to T1: left and right longus colli distance and inter-longus colli distance. We also measured three parameters on CT: left and right uncinate distance and inter-uncinate distance. Results The longus colli distances, uncinate distances, and inter-uncinate distances increased from C3 to T1. The inter-longus colli distances increased from C3 to C7. There was no difference in longus colli distances and uncinate distances between males and females. There was no difference in the six parameters for the different age groups. Conclusion Although approximate guidelines, we recommend the longus colli be dissected approximately 5 mm at C3–5, 6 mm at C5–6, 7 mm at C6–7, and 8 mm at C7–T1 to expose the uncinate process to its lateral edge. PMID:27189293

Variant palmaris profundus enclosed by an unusual loop of the median nerve

Science.gov (United States)

CHOU, HSIU-CHU; JENG, HELLEN; KO, TSUI-LING; PAI, MAN-HUI; CHANG, CHIU-YUN; WU, CHING-HSIANG

2001-01-01

According to the usual description in most anatomy texts, the median nerve in the forearm passes between the 2 heads of pronator teres. It continues distally between flexor digitorum superficialis and profundus almost to the retinaculum. Muscular branches leave the nerve near the elbow and supply all superficial muscles of the anterior part of the forearm except flexor carpi ulnaris. Many variations of the median nerve in the forearm have been reported (Urban & Krosman, 1992). The palmaris profundus is also a rare anomaly of the forearm (Dyreby & Engber, 1982). It originates from the radial side of the common flexor tendon in the proximal forearm and inserts into the undersurface of the palmar aponeurosis. The origin of palmaris profundus may be close to the median nerve and its branches, and may be involved in compressive neuropathy of the anterior interosseous nerve. Its tendon crossing through the carpal canal has been implicated in the carpal tunnel syndrome (reviewed by Lahey & Aulicino, 1986). In some cases, palmaris profundus was found enclosed in a common fascial sheath with the median nerve (Stark, 1992; Sahinoglu et al. 1994). To indicate its close association with the median nerve, the palmaris profundus was also named ‘musculus comitans nervi mediani’ (Sahinoglu et al. 1994). This article reports an unusual loop of the median nerve encircling an anomalous palmaris profundus in the forearm, which, to the best of our knowledge, has not been previously described. PMID:11693311

Catalase-positive microperoxisomes in rat soleus and extensor digitorum longus muscle fiber types

Science.gov (United States)

Riley, Danny A.; Bain, James L. W.; Ellis, Stanley

1988-01-01

The size, distribution, and content of catalase-reactive microperoxisomes were investigated cytochemically in three types of muscle fibers from the soleus and the extensor digitorum longus (EDL) of male rats. Muscle fibers were classified on the basis of the mitochondrial content and distribution, the Z-band widths, and the size and shape of myofibrils as the slow-twitch oxidative (SO), the fast-twitch oxidative glycolytic (FOG), and the fast-twitch glycolytic (FG) fibers. It was found that both the EDL and soleus SO fibers possessed the largest microperoxisomes. A comparison of microperoxisome number per muscle fiber area or the microperoxisome area per fiber area revealed following ranking, starting from the largest number and the area-ratio values: soleus SO, EDL SO, EDL FOG, and EDL FG.

Incidence and morphology of accessory heads of flexor pollicis longus and flexor digitorum profundus (Gantzer's muscles)

Science.gov (United States)

JONES, M.; ABRAHAMS, P. H.; SAÑUDO, J. R.; CAMPILLO, M.

1997-01-01

In 1813 Gantzer described 2 accessory muscles in the human forearm which bear his name (Wood, 1868; Macalister, 1875; Testut, 1884; Le Double, 1897). The more frequent of the 2 accessory muscles or ‘accessorius ad pollicem’ was found to arise from the coronoid process of the ulna, coursing distally to attach into the flexor pollicis longus muscle (flexor pollicis longus accessory head, FPLah). The less frequently observed or ‘accessorius ad flexorem profundum digitorum’ was again found to arise from the coronoid process and course to join into the flexor digitorum profundus (flexor digitorum profundus accessory head, FDPah). Since their initial description, they have been examined in further detail by a number of authors (Wood, 1868; Macalister, 1875; Le Double, 1897; Dykes & Anson, 1944; Mangini, 1960; Malhotra et al. 1982; Dellon & McKinnon, 1987; Kida, 1988). These studies, most of them focusing on the FPLah, all show different results of prevalence, origin, insertion, relations and nerve supply. We undertook this study with the aim of providing a more accurate account of the detailed morphology of both accessory muscles because of the above-mentioned inconsistent anatomical descriptions and the lack of information as to important aspects such as vascular supply, morphology (shape and length) and the coexistence of both accessory heads. PMID:9419002

The influence of the Peroneus Longus muscle on the foot under axial loading: A CT evaluated dynamic cadaveric model study.

Science.gov (United States)

Dullaert, K; Hagen, J; Klos, K; Gueorguiev, B; Lenz, M; Richards, R G; Simons, P

2016-05-01

Subtle hypermobility of the first tarsometatarsal joint can occur concomitantly with other pathologies and may be difficult to diagnose. Peroneus Longus muscle might influence stability of this joint. Collapse of the medial longitudinal arch is common in flatfoot deformity and the muscle might also play a role in correcting Meary's angle. A radiolucent frame was used to simulate weightbearing during CT examination. Eight pairs fresh-frozen lower legs were imaged in neutral position under non-weightbearing (75N), weightbearing (700N) and with 15kg weights hung from Peroneus Longus tendon. Measurements included first metatarsal rotation, intermetatarsal angle, first tarsometatarsal joint subluxation and Meary's angle. Weightbearing significantly increased Meary's angle and significantly decreased first tarsometatarsal joint subluxation (both Pfoot pathology. Weightbearing affects anatomy of the foot. No reliable information is available concerning the influence of the Peroneus muscle. This study investigates the influence of weightbearing and the impact the Peroneus muscle on the anatomy of the foot. Copyright © 2016. Published by Elsevier Ltd.

EFFECT OF UNIPOLAR ACU-STIM ON MUSCLE RE-EDUCATION FOLLOWING TENDON TRANSFER - A CASE STUDY

Directory of Open Access Journals (Sweden)

Prof. Srikanth R

2015-02-01

Full Text Available Background: Tendon transfer surgery is usually done to improve function, following damage to either major nerve trunks or peripheral nerves. Re-education of the muscle is of utmost importance to gain functional activity.To achieve this, along with re-education exercises, faradic stimulation is usually used. Unipolar Acu-Stim (UAS, is an innovative technique where an acupuncture needle is used to stimulate the transferred tendon with Surged Faradic Currents (SFC. The objective of the study is to identify if the application of SFC using UAS method, is effective to re-educate a transferred muscle. Case Description: The subject was a 24 year old male who had a loss of finger and thumb extension following Posterior Interosseous Nerve (PIN palsy, for which Flexor Carpi Radialis (FCR was transferred to Extensor Digitorum Communis (EDC and Palmaris Longus (PL was transferred to Extensor Pollicis Longus (EPL. Following removal of the POP, UAS with surged faradic current was applied for 4 weeks along with re-education exercises. Prognosis of finger extension was assessed by goniometry and video recordings. Outcome: At the end of 8th week, as observed on goniometry and video recordings, complete finger extension was achieved. Discussion: UAS with SFC, is useful in re-education of a transferred muscle, as desired movement can be achieved with low intensity.

The pyramidalis-anterior pubic ligament-adductor longus complex (PLAC) and its role with adductor injuries

DEFF Research Database (Denmark)

Schilders, Ernest; Bharam, Srino; Golan, Elan

2017-01-01

cadavers. The dimensions of the pyramidalis muscle were measured and anatomical connections with adductor longus, rectus abdominis and aponeuroses examined. RESULTS: The pyramidalis is the only abdominal muscle anterior to the pubic bone and was found bilaterally in all specimens. It arises from the pubic...... is to systematically investigate the pyramidalis muscle and its anatomical connections with adductor longus and rectus abdominis, to elucidate injury patterns occurring with adductor avulsions. METHODS: A layered dissection of the soft tissues of the anterior symphyseal area was performed on seven fresh-frozen male...... the pyramidalis muscle and adductor longus tendon via the anterior pubic ligament, and it introduces the new anatomical concept of the pyramidalis-anterior pubic ligament-adductor longus complex (PLAC). Knowledge of these anatomical relationships should be employed to aid in image interpretation and treatment...

Inflammation of vertebral bone associated with acute calcific tendinitis of the longus colli muscle

Energy Technology Data Exchange (ETDEWEB)

Mihmanli, I.; Kanberoglu, K. [Dept. of Radiology, Istanbul Univ. (Turkey); Karaarslan, E. [Intermed Medical Center, Nisantasi, Istanbul (Turkey)

2001-12-01

We present a case of acute retropharyngeal calcific tendinitis with characteristic findings on radiographic, computed tomography, and magnetic resonance imaging (MRI). To our knowledge, this is the first acute retropharyngeal calcific tendinitis report having inflammation of both the vertebra itself and the longus colli muscle diagnosed on MRI. In patients with neck pain, acute retropharyngeal calcific tendinitis should be kept in mind in the differential diagnosis, even if these patients had vertebral pathological signals on MRI. (orig.)

Inflammation of vertebral bone associated with acute calcific tendinitis of the longus colli muscle

International Nuclear Information System (INIS)

Mihmanli, I.; Kanberoglu, K.; Karaarslan, E.

2001-01-01

We present a case of acute retropharyngeal calcific tendinitis with characteristic findings on radiographic, computed tomography, and magnetic resonance imaging (MRI). To our knowledge, this is the first acute retropharyngeal calcific tendinitis report having inflammation of both the vertebra itself and the longus colli muscle diagnosed on MRI. In patients with neck pain, acute retropharyngeal calcific tendinitis should be kept in mind in the differential diagnosis, even if these patients had vertebral pathological signals on MRI. (orig.)

A rare variant of the ulnar artery with important clinical implications: a case report

Directory of Open Access Journals (Sweden)

Casal Diogo

2012-11-01

Full Text Available Abstract Background Variations in the major arteries of the upper limb are estimated to be present in up to one fifth of people, and may have significant clinical implications. Case presentation During routine cadaveric dissection of a 69-year-old fresh female cadaver, a superficial brachioulnar artery with an aberrant path was found bilaterally. The superficial brachioulnar artery originated at midarm level from the brachial artery, pierced the brachial fascia immediately proximal to the elbow, crossed superficial to the muscles that originated from the medial epicondyle, and ran over the pronator teres muscle in a doubling of the antebrachial fascia. It then dipped into the forearm fascia, in the gap between the flexor carpi radialis and the palmaris longus. Subsequently, it ran deep to the palmaris longus muscle belly, and superficially to the flexor digitorum superficialis muscle, reaching the gap between the latter and the flexor carpi ulnaris muscle, where it assumed is usual position lateral to the ulnar nerve. Conclusion As far as the authors could determine, this variant of the superficial brachioulnar artery has only been described twice before in the literature. The existence of such a variant is of particular clinical significance, as these arteries are more susceptible to trauma, and can be easily confused with superficial veins during medical and surgical procedures, potentially leading to iatrogenic distal limb ischemia.

Comparative proteomic profiling of soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscles from the mdx mouse model of Duchenne muscular dystrophy.

Science.gov (United States)

Carberry, Steven; Brinkmeier, Heinrich; Zhang, Yaxin; Winkler, Claudia K; Ohlendieck, Kay

2013-09-01

Duchenne muscular dystrophy is due to genetic abnormalities in the dystrophin gene and represents one of the most frequent genetic childhood diseases. In the X-linked muscular dystrophy (mdx) mouse model of dystrophinopathy, different subtypes of skeletal muscles are affected to a varying degree albeit the same single base substitution within exon 23 of the dystrophin gene. Thus, to determine potential muscle subtype-specific differences in secondary alterations due to a deficiency in dystrophin, in this study, we carried out a comparative histological and proteomic survey of mdx muscles. We intentionally included the skeletal muscles that are often used for studying the pathomechanism of muscular dystrophy. Histological examinations revealed a significantly higher degree of central nucleation in the soleus and extensor digitorum longus muscles compared with the flexor digitorum brevis and interosseus muscles. Muscular hypertrophy of 20-25% was likewise only observed in the soleus and extensor digitorum longus muscles from mdx mice, but not in the flexor digitorum brevis and interosseus muscles. For proteomic analysis, muscle protein extracts were separated by fluorescence two-dimensional (2D) gel electrophoresis. Proteins with a significant change in their expression were identified by mass spectrometry. Proteomic profiling established an altered abundance of 24, 17, 19 and 5 protein species in the dystrophin-deficient soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscle, respectively. The key proteomic findings were verified by immunoblot analysis. The identified proteins are involved in the contraction-relaxation cycle, metabolite transport, muscle metabolism and the cellular stress response. Thus, histological and proteomic profiling of muscle subtypes from mdx mice indicated that distinct skeletal muscles are differentially affected by the loss of the membrane cytoskeletal protein, dystrophin. Varying degrees of perturbed protein

Origin attachments of the caudofemoralis longus muscle in the Jurassic dinosaur Allosaurus

Directory of Open Access Journals (Sweden)

Andrea Cau

2017-06-01

Full Text Available The caudofemoralis longus muscle (CFL is the primary limb retractor among non-avian sauropsids, and underwent a dramatic reduction along the dinosaur lineage leading to birds. The osteological correlates of the CFL among fossil reptiles have been controversial, because, contrary to traditional interpretations, the extent of the muscle is not necessarily related to the distribution of the caudal ribs. In some Cretaceous dinosaurs, the extent of the CFL has been inferred based on the preserved bony septa between the CFL and other tail muscles. Here, we describe a series of tail vertebrae of the Jurassic dinosaur Allosaurus, each showing a previously-unreported feature: a sulcus, formed by a regular pattern of tightly packed horizontal slits, that runs vertically along the lateral surfaces of the centra and neural arches. These sulci are interpreted as the origin attachment sites of the CFL, allowing for direct determination of the muscle extent along the tail of this dinosaur. Anteriorly to the 18th caudal vertebra, the sulcus runs along most of the centrum and neural arch, then it progressively reduces its vertical extent, and disappears between caudals 24 and 32, a pattern consistent with previous CFL reconstructions in other theropods.

Flexor accessorius longus: A rare variation of the deep extrinsic digital flexors of the leg and its phylogenetic significance

Directory of Open Access Journals (Sweden)

Jaijesh P

2006-01-01

Full Text Available Anomalies of the calf muscles are rare. One such anomalous muscle, known as the Muscle Flexor accessorius longus (also named accessorius ad accessorium, accessorius secondus, accessory flexor digitorum longus or pronator pedis is of morphological significance. When present, this originates in the deep fascia of the tibia or fibula and inserts in the foot either into the flexor digitorum accessorius or into the tendons of the flexor digitorum longus. In this report we present a discussion of the morphological significance and phylogenetic history of one such muscle observed. In this case report we describe an anomalous calf muscle which extends from the popliteal region, runs along the posterior compartment of the leg, reaches the sole and is inserted to the flexor digitorum longus muscle. This kind of muscle variations are considered to be the higher origin of the flexor digitorum accessorius muscle of the sole. Here we discuss the phylogenetic history of this muscle as this muscle variant is present in some primitive mammals, absent in apes and in this particular case appeared as one of the muscles of the flexor compartment of the leg.

Lean and Obese Zucker Rat Extensor Digitorum Longus Muscle high-frequency electrical stimulation (HFES Data: Regulation of p70S6kinase Associated Proteins

Directory of Open Access Journals (Sweden)

Kevin M. Rice

2018-02-01

Full Text Available Anaerobic exercise has been advocated as a prescribed treatment for the management of diabetes: however, alterations in exercise-induced signaling remain largely unexplored in the diabetic muscle. Here, we compare the basal and the in situ contraction-induced phosphorylation of the AKT, GSK3beta, mTor, p70s6K, Pten, and Shp2 in the lean and obese (fa/fa Zucker rat Extensor Digitorum Longus (EDL muscle following a single bout of contractile stimuli. This article represents data associated with prior publications from our lab (Katta et al., 2009a, 2009b; Tullgren et al., 1991 [1–3] and concurrent Data in Brief articles (Ginjupalli et al., 2017a, 2017b; Rice et al., 2017a, 2017b [4–7]. Keywords: Diabetes, Skeletal muscle, High-frequency electrical stimulation (HFES, Zucker rat, Extensor Digitorum Longus, p70s6k

Effects of neuromuscular training on the reaction time and electromechanical delay of the peroneus longus muscle.

Science.gov (United States)

Linford, Christena W; Hopkins, J Ty; Schulthies, Shane S; Freland, Brent; Draper, David O; Hunter, Iain

2006-03-01

To examine the influence of a 6-week neuromuscular training program on the electromechanical delay and reaction time of the peroneus longus muscle. A 2 x 2 pre-post factorial design. Human performance research center biomechanics laboratory. Thirty-six healthy, physically active, college-age subjects were recruited for this study and 26 completed it. There were 5 men and 8 women in the treatment group (mean age +/- standard deviation, 21.9+/-2.1 y; height, 173.7+/-11.1cm; weight, 67.4+/-17.8 kg) and 6 men and 7 women in the control group (age, 21.8+/-2.3 y; height, 173.7+/-11.9 cm; weight, 70.8+/-19.4 kg). Subjects were not currently experiencing any lower-extremity pathology and had no history of injuries requiring treatment to either lower extremity. Subjects in the treatment group completed a 6-week neuromuscular training program involving various therapeutic exercises. Subjects in the control group were asked to continue their normal physical activity during the 6-week period. The electromechanical delay of the peroneus longus was determined by the onset of force contribution after artificial activation, as measured by electromyographic and forceplate data. Reaction time was measured after a perturbation during walking. Data were analyzed using two 2 x 2 analyses of covariance (covariate pretest score). Group (treatment, control) and sex (male, female) were between-subject factors. Neuromuscular training caused a decrease in reaction time to perturbation during walking compared with controls (F=4.030, P=.029), while there was a trend toward an increase in electromechanical delay (F=4.227, P=.052). There was no significant difference between sexes or the interaction of sex and treatment in either reaction time or electromechanical delay. The 6-week training program significantly reduced reaction time of the peroneus longus muscle in healthy subjects. Neuromuscular training may have a beneficial effect on improving dynamic restraint during activity.

Recombinant Uncarboxylated Osteocalcin Per Se Enhances Mouse Skeletal Muscle Glucose Uptake in both Extensor Digitorum Longus and Soleus Muscles

Directory of Open Access Journals (Sweden)

Xuzhu Lin

2017-11-01

Full Text Available Emerging evidence suggests that undercarboxylated osteocalcin (ucOC improves muscle glucose uptake in rodents. However, whether ucOC can directly increase glucose uptake in both glycolytic and oxidative muscles and the possible mechanisms of action still need further exploration. We tested the hypothesis that ucOC per se stimulates muscle glucose uptake via extracellular signal-regulated kinase (ERK, adenosine monophosphate-activated protein kinase (AMPK, and/or the mechanistic target of rapamycin complex 2 (mTORC2-protein kinase B (AKT-AKT substrate of 160 kDa (AS160 signaling cascade. Extensor digitorum longus (EDL and soleus muscles from male C57BL/6 mice were isolated, divided into halves, and then incubated with ucOC with or without the pretreatment of ERK inhibitor U0126. ucOC increased muscle glucose uptake in both EDL and soleus. It also enhanced phosphorylation of ERK2 (Thr202/Tyr204 and AS160 (Thr642 in both muscle types and increased mTOR phosphorylation (Ser2481 in EDL only. ucOC had no significant effect on the phosphorylation of AMPKα (Thr172. The inhibition of ucOC-induced ERK phosphorylation had limited effect on ucOC-stimulated glucose uptake and AS160 phosphorylation in both muscle types, but appeared to inhibit the elevation in AKT phosphorylation only in EDL. Taken together, ucOC at the physiological range directly increased glucose uptake in both EDL and soleus muscles in mouse. The molecular mechanisms behind this ucOC effect on muscle glucose uptake seem to be muscle type-specific, involving enhanced phosphorylation of AS160 but limitedly modulated by ERK phosphorylation. Our study suggests that, since ucOC increases muscle glucose uptake without insulin, it could be considered as a potential agent to improve muscle glucose uptake in insulin resistant conditions.

Nomenclatural review of long digital forelimb flexors in carnivores.

Science.gov (United States)

Spoor, C F; Badoux, D M

1986-12-01

A hitherto-unknown atavistic muscle in the dog initiated a review of the literature on the homologies and nomenclature of the forelimb flexors in carnivores and man. A consequence is that we recommend a revision of the nomenclature in the Nomina Anatomica Veterinaria (Ithaca, New York, 1983) so that it is in agreement with the Nomina Anatomica (Wilkins, Baltimore, 1983). This revision mainly consists of the incorporation of the terms M. palmaris longus and Mm. flexores breves manus.

Effect of Electroacupuncture on the Expression of Glycyl-tRNA Synthetase and Ultrastructure Changes in Atrophied Rat Peroneus Longus Muscle Induced by Sciatic Nerve Injection Injury

Directory of Open Access Journals (Sweden)

Meng Wang

2016-01-01

Full Text Available Glycyl-tRNA synthetase (GlyRS is one of the key enzymes involved in protein synthesis. Its mutations have been reported to cause Charcot-Marie-Tooth disease which demonstrates muscular atrophy in distal extremities, particularly manifested in peroneus muscles. In this situation, the dysfunctions of mitochondria and sarcoplasmic reticulum (SR affect energy supply and excitation-contraction coupling of muscle fibers, therefore resulting in muscular atrophy. Although the treatment of muscular atrophy is a global urgent problem, it can be improved by electroacupuncture (EA treatment. To investigate the mechanism underlying EA treatment improving muscular atrophy, we focused on the perspective of protein synthesis by establishing a penicillin injection-induced sciatic nerve injury model. In our model, injured rats without treatment showed decreased sciatic functional index (SFI, decreased peroneus longus muscle weight and muscle fiber cross-sectional area, aggregated mitochondria with vacuoles appearing, swollen SR, and downregulated mRNA and protein expression levels of GlyRS and myosin heavy chain IIb (MHC-IIb. The injured rats with EA treatment showed significant recovery. These results indicated that EA stimulation can alleviate peroneus longus muscular atrophy induced by iatrogenic sciatic nerve injury through promoting the recovery of GlyRS and muscle ultrastructure and increasing muscle protein synthesis.

Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man.

Science.gov (United States)

Kato, Kenji; Sasada, Syusaku; Nishimura, Yukio

2016-02-01

Controlling a neuroprosthesis requires learning a novel input-output transformation; however, how subjects incorporate this into limb control remains obscure. To elucidate the underling mechanisms, we investigated the motor adaptation process to a novel artificial recurrent connection (ARC) from a muscle to a peripheral nerve in healthy humans. In this paradigm, the ulnar nerve was electrically stimulated in proportion to the activation of the flexor carpi ulnaris (FCU), which is ulnar-innervated and monosynaptically innervated from Ia afferents of the FCU, defined as the "homonymous muscle," or the palmaris longus (PL), which is not innervated by the ulnar nerve and produces similar movement to the FCU, defined as the "synergist muscle." The ARC boosted the activity of the homonymous muscle and wrist joint movement during a visually guided reaching task. Participants could control muscle activity to utilize the ARC for the volitional control of wrist joint movement and then readapt to the absence of the ARC to either input muscle. Participants reduced homonymous muscle recruitment with practice, regardless of the input muscle. However, the adaptation process in the synergist muscle was dependent on the input muscle. The activity of the synergist muscle decreased when the input was the homonymous muscle, whereas it increased when it was the synergist muscle. This reorganization of the neuromotor map, which was maintained as an aftereffect of the ARC, was observed only when the input was the synergist muscle. These findings demonstrate that the ARC induced reorganization of neuromotor map in a targeted and sustainable manner. Copyright © 2016 the American Physiological Society.

Ultrasonographic features of an adductor longus tear: case report

Energy Technology Data Exchange (ETDEWEB)

Goh, Lesley-Ann Hui-huan [Tan Tock Seng Hospital (Singapore); Rethy, C.K.; Wang Shih-chang [National Univ. Hospital (Singapore); Tho Kam San [Alexandra Hospital (Singapore)

2001-08-01

Muscle strain of the lower extremities is among the most common injuries in sports. Excessive force, rather than direct trauma, causes disruption of the muscle-tendon unit, usually at the myotendinous junction, and improper rest and rehabilitation of a minor strain can often lead to a far more disabling injury. High-resolution ultrasonography is useful for direct imaging of muscle injuries. We present a case where ultrasonography was used to detect, treat and follow-up an adductor longus tear in a soccer player. (author)

Ultrasonographic features of an adductor longus tear: case report

International Nuclear Information System (INIS)

Goh, Lesley-Ann Hui-huan; Rethy, C.K.; Wang Shih-chang; Tho Kam San

2001-01-01

Muscle strain of the lower extremities is among the most common injuries in sports. Excessive force, rather than direct trauma, causes disruption of the muscle-tendon unit, usually at the myotendinous junction, and improper rest and rehabilitation of a minor strain can often lead to a far more disabling injury. High-resolution ultrasonography is useful for direct imaging of muscle injuries. We present a case where ultrasonography was used to detect, treat and follow-up an adductor longus tear in a soccer player. (author)

In vivo fascicle behavior of the flexor hallucis longus muscle at different walking speeds.

Science.gov (United States)

Péter, A; Hegyi, A; Finni, T; Cronin, N J

2017-12-01

Ankle plantar flexor muscles support and propel the body in the stance phase of locomotion. Besides the triceps surae, flexor hallucis longus muscle (FHL) may also contribute to this role, but very few in vivo studies have examined FHL function during walking. Here, we investigated FHL fascicle behavior at different walking speeds. Ten healthy males walked overground at three different speeds while FHL fascicle length changes were recorded with ultrasound and muscle activity was recorded with surface electromyography (EMG). Fascicle length at heel strike at toe off and at peak EMG activity did not change with speed. Range of FHL fascicle length change (3.5-4.5 and 1.9-2.9 mm on average in stance and push-off phase, respectively), as well as minimum (53.5-54.9 and 53.8-55.7 mm) and maximum (58-58.4 and 56.8-57.7 mm) fascicle length did not change with speed in the stance or push-off phase. Mean fascicle velocity did not change in the stance phase, but increased significantly in the push-off phase between slow and fast walking speeds (P=.021). EMG activity increased significantly in both phases from slow to preferred and preferred to fast speed (P<.02 in all cases). FHL muscle fascicles worked near-isometrically during the whole stance phase (at least during slow walking) and operated at approximately the same length at different walking speeds. FHL and medial gastrocnemius (MG) have similar fiber length to muscle belly length ratios and, according to our results, also exhibit similar fascicle behavior at different walking speeds. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Does the longus colli have an effect on cervical vertigo?

Science.gov (United States)

Liu, Xiao-Ming; Pan, Fu-Min; Yong, Zhi-Yao; Ba, Zhao-yu; Wang, Shan-Jin; Liu, Zheng; Zhao, Wei-dong; Wu, De-Sheng

2017-01-01

Abstract The aim of the study was to evaluate the role of the longus colli muscles in cervical vertigo. We retrospectively analyzed 116 adult patients who underwent anterior cervical discectomy and fusion (ACDF) during 2014 in our department. Patients were assigned to the vertigo group or the nonvertigo group. Demographic data were recorded. Inner distance and cross-sectional area (CSA) of longus colli were measured using coronal magnetic resonance imaging (MRI). The vertigo group (n = 44) and the nonvertigo group (n = 72) were similar in demographic data. Mean preoperative Japanese Orthopaedic Association (JOA) score was higher in the vertigo group than in the nonvertigo group (P = 0.037), but no difference postoperatively. Mean JOA scores increased significantly postoperatively in both groups (P = 0.002 and P = 0.001). The mean vertigo score decreased significantly from pre- to postoperatively in the vertigo group (P = 0.023). The mean preoperative Cobb angle was significantly smaller in the vertigo group than in the nonvertigo group (P vertigo group (P vertigo group (P vertigo group than in the nonvertigo group. Mean Miyazaki scores were significantly higher in the vertigo group at C3/4 and C4/5 (P = 0.044 and P = 0.037). Moreover, a shorter inner distance and smaller CSA were related to a higher Miyazaki score. Inner distance and cross-sectional area (CSA) of longus colli are associated closely with cervical vertigo. Shorter inner distance and smaller CSA of the longus colli muscles might be risk factors for cervical vertigo. ACDF provided a good resolution of cervical vertigo. PMID:28328822

Bilateral congenital absence of flexor pollicis longus with thumb hypoplasia and thenar atrophy

International Nuclear Information System (INIS)

Chaudhary, Vikas; Sehgal, Harsha; Bano, Shahina; Parmar, Pranjali R; Kumar, Sanjay

2014-01-01

Congenital absence of flexor pollicis longus with or without associated anomalies of thenar muscles and thumb is of rare occurrence. Inability to flex the interphalangeal joint of the thumb and absent dorsal wrinkles and flexion creases of the thumb are important clues to the diagnosis. Routine radiography and cross-sectional imaging help to confirm and document the condition. This article presents an extremely rare case of bilateral congenital absence of flexor pollicis longus tendon with thumb hypoplasia and thenar atrophy

Acute neck pain due to tendonitis of the longus colli: CT and MRI findings

International Nuclear Information System (INIS)

Artenian, D.J.; Lipman, J.K.; Scidmore, G.K.; Brant-Zawadzki, M.

1989-01-01

Calcific retropharyngeal tendonitis is an under-recognized cause of acute cervical pain produced by inflammation of the longus colli muscle. Although the clinical presentation may mimic more serious disorders, the diagnosis can be established radiographically by identification of prevertebral soft tissue calcification and swelling. Six patients with typical signs and symptoms of retropharyngeal tendonitis are presented. All were evaluated with plain films, four with CT and one with MRI. The pathognomonic finding of amorphous calcification anterior to C1-2 with associated asymmetric soft tissue swelling was clearly demonstrated by CT. Diffuse swelling of the longus colli muscle was shown as prominent high signal in the prevertebral region by T2 weighted MRI. (orig.)

Acute neck pain due to tendonitis of the longus colli: CT and MRI findings

Energy Technology Data Exchange (ETDEWEB)

Artenian, D J; Lipman, J K; Scidmore, G K; Brant-Zawadzki, M

1989-05-01

Calcific retropharyngeal tendonitis is an under-recognized cause of acute cervical pain produced by inflammation of the longus colli muscle. Although the clinical presentation may mimic more serious disorders, the diagnosis can be established radiographically by identification of prevertebral soft tissue calcification and swelling. Six patients with typical signs and symptoms of retropharyngeal tendonitis are presented. All were evaluated with plain films, four with CT and one with MRI. The pathognomonic finding of amorphous calcification anterior to C1-2 with associated asymmetric soft tissue swelling was clearly demonstrated by CT. Diffuse swelling of the longus colli muscle was shown as prominent high signal in the prevertebral region by T2 weighted MRI.

Effects of chronic administration of clenbuterol on contractile properties and calcium homeostasis in rat extensor digitorum longus muscle.

Science.gov (United States)

Sirvent, Pascal; Douillard, Aymerick; Galbes, Olivier; Ramonatxo, Christelle; Py, Guillaume; Candau, Robin; Lacampagne, Alain

2014-01-01

Clenbuterol, a β2-agonist, induces skeletal muscle hypertrophy and a shift from slow-oxidative to fast-glycolytic muscle fiber type profile. However, the cellular mechanisms of the effects of chronic clenbuterol administration on skeletal muscle are not completely understood. As the intracellular Ca2+ concentration must be finely regulated in many cellular processes, the aim of this study was to investigate the effects of chronic clenbuterol treatment on force, fatigue, intracellular calcium (Ca2+) homeostasis and Ca2+-dependent proteolysis in fast-twitch skeletal muscles (the extensor digitorum longus, EDL, muscle), as they are more sensitive to clenbuterol-induced hypertrophy. Male Wistar rats were chronically treated with 4 mg.kg-1 clenbuterol or saline vehicle (controls) for 21 days. Confocal microscopy was used to evaluate sarcoplasmic reticulum Ca2+ load, Ca2+-transient amplitude and Ca2+ spark properties. EDL muscles from clenbuterol-treated animals displayed hypertrophy, a shift from slow to fast fiber type profile and increased absolute force, while the relative force remained unchanged and resistance to fatigue decreased compared to control muscles from rats treated with saline vehicle. Compared to control animals, clenbuterol treatment decreased Ca2+-transient amplitude, Ca2+ spark amplitude and frequency and the sarcoplasmic reticulum Ca2+ load was markedly reduced. Conversely, calpain activity was increased by clenbuterol chronic treatment. These results indicate that chronic treatment with clenbuterol impairs Ca2+ homeostasis and this could contribute to the remodeling and functional impairment of fast-twitch skeletal muscle.

Proximo-distal organization and fibre type regionalization in rat hindlimb muscles

NARCIS (Netherlands)

Wang, LC; Kernell, D

Five muscles of the rat's lower hindlimb were compared with regard to their histochemical fibre type distribution at seven different proximo-distal levels. The muscles were: extensor digitorum longus (ED), flexor digitorum and hallucis longus (FD), gastrocnemius medialis (GM), peroneus longus (PE)

The relation between maximal voluntary force in m. palmaris longus and the temporal and spatial summation of muscle fiber recruitment in human subjects

DEFF Research Database (Denmark)

Claudel, Cécyl G.; Ahmed, Waqas; Elbrønd, Vibeke S.

2018-01-01

that AMG is a noninvasive method which can be readily applied to accurately describe how a subject uses a given muscle during any given movement. These findings have relevance when considering training strategies in subjects with muscle trauma or disease, in the elderly, or for both amateur and top...

Longer reaction time of the fibularis longus muscle and reduced postural control in basketball players with functional ankle instability: A pilot study.

Science.gov (United States)

Méndez-Rebolledo, Guillermo; Guzmán-Muñoz, Eduardo; Gatica-Rojas, Valeska; Zbinden-Foncea, Hermann

2015-08-01

Motor control evaluation in subjects with functional ankle instability is questionable when both ankles of the same subject are compared (affected vs non-affected). To compare the postural control and reaction time of ankle muscles among: basketball players with FAI (instability group), basketball players without FAI (non-instability group) and healthy non-basketball-playing participants (control group). Case-control study. Laboratory. Instability (n = 10), non-instability (n = 10), and control groups (n = 11). Centre of pressure variables (area, velocity and sway) were measured with a force platform. Reaction time of ankle muscles was measured via electromyography. A one-way ANOVA demonstrated that there were significant differences between the instability and non-instability groups in the fibularis longus (p postural control and longer reaction time of the fibularis and tibialis anterior muscles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reconstruction of a Total Soft Palatal Defect Using

Directory of Open Access Journals (Sweden)

Won Jai Lee

2012-01-01

Full Text Available Background The soft palate functions as a valve and helps generate the oral pressurerequired for normal speech resonance. Speech problems and nasal regurgitation can resultfrom a soft palatal defect. Reduction of the size of the velopharyngeal orifice is requiredto compensate for the lack of mobility in a reconstructed soft palate. We suggest a largevolume folded free flap for reduction of the caliber and a palmaris longus tendon sling forsuspension of the reconstructed palate.Methods Six patients had total soft palate resection for tonsillar cancer and reconstructionwith a large volume folded radial forearm free flap combined with a palmaris longus sling.A single surgeon and speech therapist examined the patients with three standardizedspeech assessment tools: nasometer test, consonant articulation test, and speech acuity testperformed for speech evaluation.Results Mean nasalance score was 76.20% for sentences with nasal sounds and 43.60% forsentences with oral sounds. Hypernasality was seen for oral sound sentences. The mean scoreof the picture consonant articulation test was 84% (range, 63% to 100%. The mean scoreof the speech acuity test was 5.84 (range, 5 to 6. These mean ratings represent a satisfactorylevel of speech function.Conclusions The large volume folded free flap with a palmaris longus tendon sling for totalsoft palate reconstruction resulted in satisfactory prognosis for speech despite moderatehypernasality.

Skeletal muscle CT of lower extremities in myotonic dystrophy

International Nuclear Information System (INIS)

Takahashi, Ryosuke; Imai, Terukuni; Sadashima, Hiromichi; Matsumoto, Sadayuki; Yamamoto, Toru; Kusaka, Hirofumi; Yamasaki, Masahiro; Maya, Kiyomi; Tanabe, Masaya

1988-01-01

We evaluated the leg and thigh muscles of 4 control subjects and 10 patients with myotonic dystrophy using computed tomography. Taking previous reports about the skeletal muscle CT of myotonic dystrophy into account, we concluded that the following 5 features are characteristic of myotonic dystrophy: 1. The main change is the appearance of low-density areas in muscles; these areas reflect fat tissue. In addition, the muscle mass decreases in size. 2. The leg is more severely affected than the thigh. 3. In the thigh, although the m. quadriceps femoris, especially the vastus muscles, tends to be affected, the m. adductor longus and magnus tend to be preserved. 4. In the leg, although the m. tibialis anterior and m. triceps surae tend to be affected, the m. peroneus longus, brevis, and m. tibialis posterior tend to be preserved. 5. Compensatory hypertrophy is often observed in the m. rectus femoris, m. adductor longus, m. adductor magnus, m. peroneus longus, and m. peroneus brevis, accompanied by the involvement of their agonist muscles. (author)

MR imaging of flexor digitorum accessorius longus

International Nuclear Information System (INIS)

Cheung, Y.Y.; Rosenberg, Z.S.; Colon, E.; Jahss, M.

1999-01-01

Objective The flexor digitorum accessorius longus muscle (FDAL), an anomalous muscle about the ankle, has recently been implicated in tarsal tunnel syndrome. The purpose of this study is to document the prevalence of the FDAL, its MR appearance and its relation to the neurovascular bundle in the tarsal tunnel. Design and patients The prevalence of the FDAL was determined from 100 ankle MR examinations in asymptomatic individuals. The appearance of the FDAL was summarized from 20 examples of FDAL: six gathered from the asymptomatic group and 14 acquired from a group of randomly collected cases of patients with ankle complaints. Results The prevalence of the FDAL was 6%, calculated from the group of 100 asymptomatic individuals. Possessing a dominant fleshy component in the tarsal tunnel, the FDAL accompanies the posterior neurovascular bundle as it descends the ankle. Conclusion The FDAL is encountered in 6% of asymptomatic individuals. Its prominent fleshy component in the tarsal tunnel and its close proximity to the posterior tibial neurovascular bundle readily differentiate the FDAL from other medial anomalous muscles on MR imaging. (orig.)

Complete avulsion of the adductor longus in a semi-professional football player: Rapid return to play with nonoperative treatment

Directory of Open Access Journals (Sweden)

Vince W Lands

2016-01-01

Full Text Available The adductor longus has become recognized as one of the more commonly injured muscles in the medial compartment. Acute complete rupture injuries occurring at the proximal aspect of the muscle are less common. Limited data exist regarding management of the injuries in athletes required for return to play and functioning. The current data favors operative management; however, nonoperative treatment may be a viable option. Nonoperative management of avulsion injuries of the proximal adductor longus tendon may prove equal results to surgical repair in return to play and functioning. A semi-professional football player sustained a left groin injury while participating in the play. Due to continued pain, swelling, and suspicion of injury, a magnetic resonance imaging was performed diagnosing a complete tear of proximal adductor longus tendon. Physical examination, strength, and range of motion were recorded until the patient was able to function normally without strength deficit, the range of motion loss, and the return of speed. The player was treated nonoperatively and was eventually allowed to return to play. The time of return to play was 6 weeks. Strength deficit was not appreciated or loss of motion and player was able to return to baseline function. Nonoperative management of complete avulsion injuries of the proximal adductor longus tendon result in faster return to play than operative management even if significant retraction is present.

EMG and force production of the flexor hallucis longus muscle in isometric plantarflexion and the push-off phase of walking.

Science.gov (United States)

Péter, Annamária; Hegyi, András; Stenroth, Lauri; Finni, Taija; Cronin, Neil J

2015-09-18

Large forces are generated under the big toe in the push-off phase of walking. The largest flexor muscle of the big toe is the flexor hallucis longus (FHL), which likely contributes substantially to these forces. This study examined FHL function at different levels of isometric plantarflexion torque and in the push-off phase at different speeds of walking. FHL and calf muscle activity were measured with surface EMG and plantar pressure was recorded with pressure insoles. FHL activity was compared to the activity of the calf muscles. Force and impulse values were calculated under the big toe, and were compared to the entire pressed area of the insole to determine the relative contribution of big toe flexion forces to the ground reaction force. FHL activity increased with increasing plantarflexion torque level (F=2.8, P=0.024) and with increasing walking speed (F=11.608, Ppush-off phase of walking, peak force under the big toe increased at a higher rate than force under the other areas of the plantar surface (F=3.801, P=0.018), implying a greater relative contribution to total force at faster speeds. Moreover, substantial differences were found between isometric plantarflexion and walking concerning FHL activity relative to that of the calf muscles, highlighting the task-dependant behaviour of FHL. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structural and functional anatomy of the palmaris brevis: grasping for answers.

Science.gov (United States)

Moore, Colin W; Rice, Charles L

2017-12-01

The palmaris brevis (PB) is a small cutaneous hand muscle that has been described as the most mysterious muscle from a functional and developmental perspective [Kaplan () Kaplan's Functional and Surgical Anatomy of the Hand]. Functionally, the PB is considered to deepen the hollow of the palm and to protect the neurovasculature of the ulnar canal. Although the function of the PB has been inferred from cadaveric observations, the electromyographic (EMG) activity of this muscle has not been explored systematically during specific movements of the hand. The purpose of this study was to record PB intramuscular EMG activity during dynamic grasping tasks, and to quantify the change in PB muscle length (M L ) and thickness (M T ) incurred during maximal contraction using ultrasound imaging. Intramuscular EMG was recorded from the PB in the dominant hands of 12 healthy participants (11 males, one female; age: 27 ± 4 years) during maximal abduction, flexion and opposition of the 5th digit, and two grasping tasks. Abduction of the 5th digit yielded the greatest EMG activity in most individuals (seven out of 11), and produced significantly less PB EMG activity when compared with grasping a cylindrical-shaped object (P = 0.003) but not a spherical-shaped object (P = 0.130). During maximal abduction of the 5th digit, PB M L decreased in both the left (28 ± 11%; P = 0.002) and right (32 ± 5%; P = 0.002) hands. Similarly, a concomitant increase in PB M T was observed in the left (68 ± 30%; P = 0.002) and right (85 ± 44%; P = 0.002) hands during the same contraction. These EMG results indicate that the PB is voluntarily activated during prehensile and non-prehensile movements of the hand with significant changes in muscle architecture. The study supports the preservation of the PB in surgical procedures based on its proposed protective role as a muscular barrier to the neurovasculature within the ulnar canal. © 2017 Anatomical Society.

A rare cause of acute dysphagia: acute calcific tendonitis of the longus colli muscle.

Science.gov (United States)

Abou Dargham, Hanadi; Bytyci, Faton; Shuman, Christian; Stolear, Anton

2017-05-27

We are presenting a case of a 78-year-old female with multiple comorbidities and history of neck surgery, who presented with acute dysphagia, odynophagia and neck pain that has been progressively getting worse over the course of 2 days, with no recent injury or infection. The patient was afebrile. There were no visible signs of infection on routine oropharyngeal examination. Initial workup was unremarkable except for elevated erythrocyte sedimentation rate, C-reactive protein and creatinine. CT of the cervical spine ruled out any fracture or cervical spine injury but showed an area of calcification, prevertebral oedema and fluid collection inferior to the anterior arch of C1. MRI of the cervical spine also showed prevertebral oedema and fluid collection in the retropharyngeal space from the skull base to the C3 level without abnormal surrounding enhancement that supported the diagnosis of acute calcific tendonitis of the longus colli muscle rather than an infectious process. There was significant improvement of symptoms 48 hours after initiating treatment with systemic steroids. The patient remains asymptomatic 6 months after treatment. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Extramuscular myofascial force transmission within the rat anterior tibial compartment: Proximodistal differences in muscle force

NARCIS (Netherlands)

Huijing, P.A.J.B.M.; Baan, G.C.

2001-01-01

Intramuscular connective tissues are continuous to extramuscular connective tissues. If force is transmitted there, differences should be present between force at proximal and distal attachments of muscles. Extensor digitorum longus (EDL), tibialis anterior (TA), and extensor hallucis longus muscles

Muscular hypertrophy and atrophy in normal rats provoked by the administration of normal and denervated muscle extracts.

Science.gov (United States)

Agüera, Eduardo; Castilla, Salvador; Luque, Evelio; Jimena, Ignacio; Leiva-Cepas, Fernando; Ruz-Caracuel, Ignacio; Peña, José

2016-12-01

This study was conducted to determine the effects of extracts obtained from both normal and denervated muscles on different muscle types. Wistar rats were used and were divided into a control group and four experimental groups. Each experimental group was treated intraperitoneally during 10 consecutive days with a different extract. These extracts were obtained from normal soleus muscle, denervated soleus, normal extensor digitorum longus, and denervated extensor digitorum longus. Following treatment, the soleus and extensor digitorum longus muscles were obtained for study under optic and transmission electron microscope; morphometric parameters and myogenic responses were also analyzed. The results demonstrated that the treatment with normal soleus muscle and denervated soleus muscle extracts provoked hypertrophy and increased myogenic activity. In contrast, treatment with extracts from the normal and denervated EDL had a different effect depending on the muscle analyzed. In the soleus muscle it provoked hypertrophy of type I fibers and increased myogenic activity, while in the extensor digitorum longus atrophy of the type II fibers was observed without changes in myogenic activity. This suggests that the muscular responses of atrophy and hypertrophy may depend on different factors related to the muscle type which could be related to innervation.

Activation of the hip adductor muscles varies during a simulated weight-bearing task.

Science.gov (United States)

Hides, Julie A; Beall, Paula; Franettovich Smith, Melinda M; Stanton, Warren; Miokovic, Tanja; Richardson, Carolyn

2016-01-01

To investigate the pattern of muscle activation of the individual hip adductor muscles using a standardised simulated unilateral weight-bearing task. A repeated measures design. Laboratory. 20 healthy individuals (11 females, 9 males) participated in the study. Age ranged from 20 to 25 years. Surface electromyography recordings from adductor magnus and adductor longus muscles were taken at levels representing 10-50% of body weight during a simulated weight-bearing task. Electromyography (EMG) data were normalised to maximal voluntary isometric contraction. The adductor magnus was recruited at significantly higher levels than the adductor longus muscle during a simulated weight-bearing task performed across 10-50% of body weight (p bearing task. This information should be considered when selecting exercises for management and prevention of groin strains. Closed chain exercises with weight-bearing through the lower limb are more likely to recruit the adductor magnus muscle over the adductor longus muscle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sonography findings in tears of the extensor pollicis longus tendon and correlation with CT, MRI and surgical findings

International Nuclear Information System (INIS)

Ruiz Santiago, Fernando; Garofano Plazas, Pilar; Fernandez, Juan Miguel Tristan

2008-01-01

We present our experience in the diagnosis of extensor pollicis longus tendon tears using different imaging methods. In the past 2 years, 12 patients (7 males, 5 females) with extension deficit of distal phalanx of thumb were diagnosed with extensor pollicis longus tendon (EPL) rupture by means of different imaging methods. The ultrasound pattern consisted of a gap between tendon stumps occupied by a continuous (eight cases) or discontinuous (four cases) attenuated hypoechoic string. In nine cases, the tendon ends were identified as a thickened stump-like structure. In the other three cases, tendon stumps were attenuated and mixed with atrophic muscle or wrist subcutaneous fat. All ultrasound findings were confirmed by CT, MR and/or surgical findings

Author Details

African Journals Online (AJOL)

Is there an increased risk of post-operative surgical site infection after orthopaedic surgery in Hiv patients? A systematic review and meta-analysis. Abstract PDF · Vol 7, No 1 (2013) - Articles The relationship between functional absence of the Flexor Digitorum Superficialis to the fifth digit and absence of the Palmaris Longus

Browse Title Index

African Journals Online (AJOL)

Items 1 - 50 of 217 ... Browse Title Index. Journal Home > Advanced ... Vol 13, No 1 (2016), Access to specialized surgical care, Abstract PDF. H Saidi ... Vol 9, No 2 (2012), Clinical Assessment of the Palmaris Longus – Accuracy of common tests, Abstract PDF ... Vol 11, No 2 (2014), Clinical trials in Surgery, Abstract PDF.

Electromyography comparison of the effects of various footwear in the activity patterns of the peroneus longus and brevis muscles.

Science.gov (United States)

Roca-Dols, Andrea; Losa-Iglesias, Marta Elena; Sánchez-Gómez, Rubén; López-López, Daniel; Becerro-de-Bengoa-Vallejo, Ricardo; Calvo-Lobo, César

2018-06-01

Peroneus longus and brevis (PLB) disorders are commonly in people with lateral ligamentous instability, ankle pain, lateral hindfoot pain and structures of the proximal compartment of the lower legs and their muscle activity is believed to be influenced by different footwear types. The proposal of this research is to evaluate the effects of five types of footwear with respect to the barefoot condition and analyze the activity patterns of PLB muscles in healthy subjects during the gait cycle. Thirty healthy subjects were recruited in a laboratory in this cross-sectional research design. While walking, electromyography (EMG) activity was measured from PLB via surface electrodes in six experimental conditions: 1) barefoot, 2) minimalist, 3) pronated control, 4) air chamber, 5) ethyl-vinyl-acetate (EVA) and 6) boost. These data were obtained and compared. The peroneus brevis showed significant reductions in the peak amplitude of the five footwear types (minimalist, pronation control, air chamber, EVA and boost) with respect to the barefoot condition in the propulsion phase of the gait cycle during walking (P = 0.034; P footwear types with respect to the barefoot condition in the propulsion phase of the gait cycle during running (P = 0.005; P = 0.038; P = 0.019; P = 0.025; P = 0.021). The EMG activity patterns of the PLB muscles may depend on the use of different types of sport shoes such as minimalist, pronation control, air chamber, EVA and boost footwear with respect the barefoot condition in different phases of the gait cycle during walking and running. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Rare Cause of Dysphagia to Remember: Calcific Tendinitis of the Longus Colli Muscle

OpenAIRE

Colella, Dominic M.; Calder?n Sandoval, Fiorela; Powers, David W.; Patel, Nimal; Sobrado, Javier

2016-01-01

Longus colli tendinitis (LCT) is an acute inflammatory condition with symptoms typically consisting of acute neck pain and stiffness with or without dysphagia. Once more severe etiologies for these symptoms are ruled out, this self-limiting condition usually resolves spontaneously with nonsteroidal anti-inflammatory drugs and corticosteroids. We present a case of LCT that presented as acute neck pain, dysphagia, and odynophagia that rapidly resolved once diagnosed and treated with anti-inflam...

PERONEUS LONGUS ACTIVITY IN DIFFERENT TYPES OF TAPING: ATHLETES WITH ANKLE INSTABILITY

Directory of Open Access Journals (Sweden)

Muhammad Rahmani Jaffar

Full Text Available ABSTRACT Introduction: Participation in sport among university athletes in Malaysia has progressed right up to Olympic level. However, some of these athletes are prevented from competing due to injuries. Ankle injuries, in particular, are among the common types of injury. Even so, there is still lack of local data and research describing the incidence of ankle injuries. Objectives: To determine peroneus longus muscle activity in different taped ankles and positions among subjects with functional ankle instability (FAI. Methods: Twenty-three subjects with ankle instability (AJFAT score > 26 volunteered to take part in the study. The subjects were tested under three conditions; 1 no tape (NT, 2 Kinesio(r tape (KT, and 3 rigid tape (RT. The subjects completed two postural stability tests, followed by a sudden inversion perturbation test with EMG, recording throughout the procedures. The EMG data were analyzed, filtered, full-wave rectified and normalized. The data were analyzed by analysis of variance (Independent T-test and ANOVA to evaluate differences in peak muscle activation (mV and peroneal latency (ms. Results: Peak muscle activation of the peroneus was activated more in the RT group during both the Static and Dynamic Stability Tests. Apart from that, there were no statistically significant differences. During sudden inversion perturbation, the RT group was the one that was most activated (p=0.001. Peroneal latency was even delayed in KT and RT during the three tests, and shorter in the NT group. There were significant differences during the Dynamic Stability Test, between the NT and KT groups (p=0.001 and between the NT, RT and KT groups (p=0.001. Conclusion: RT tape may enhance the peroneus longus response by maintaining a higher level of muscle activation, especially during dynamic movements and sudden inversion of the ankle, and may selectively benefit individuals with FAI. The KT ankle did not show superior effect to the NT ankle, and

MR imaging of accessory muscles of the ankle

International Nuclear Information System (INIS)

Mondello, Eduardo; Nazar, Miguel E.; Martin, Eduardo

2001-01-01

Purpose: The purpose of this work is to describe the normal anatomy and the characteristics in MRI of the accessory muscles of the posterior ankle: the accessory soleus, accessory flexor digitorum longus, peroneus quartus, tibiocalcaneus internus and peroneocalcaneus internus. Material and methods: There were evaluated 280 symptomatic patients between 18 and 40 years old (85 % males). MR was performed in High Field Magnetic Resonance Units (1.5 T y 1.0 T) and multiplanar sequences. Results: We found 2 peroneus quartus (0.7%), 2 accessory soleus muscles (0.7%), 3 accessory flexor digitorum longus (1.07%) and 1 peroneocalcaneus internus (0.35%). Conclusion: The knowledge of the accessory muscles of the posterior ankle allow to explain different painful pathologies with instability or tendinous tears, which are difficult to diagnose if the muscle are not adequately recognized. (author)

Peroneus longus tenosynovitis.

OpenAIRE

Folan, J. C.

1981-01-01

Tenosynovitis of the tendon of peroneus longus has rarely been described in the literature (Aberle-Horstenegg, 1932; Burman and Lapidus, 1931). This is a report on the condition in two athletes and in one of whom the os peroneum was absent on the side of the tenosynovitis. It emphasises the importance of a detailed review of athletes' training patterns when assessing their injuries.

Muscle stiffness of posterior lower leg in runners with a history of medial tibial stress syndrome.

Science.gov (United States)

Saeki, J; Nakamura, M; Nakao, S; Fujita, K; Yanase, K; Ichihashi, N

2018-01-01

Previous history of medial tibial stress syndrome (MTSS) is a risk factor for MTSS relapse, which suggests that there might be some physical factors that are related to MTSS development in runners with a history of MTSS. The relationship between MTSS and muscle stiffness can be assessed in a cross-sectional study that measures muscle stiffness in subjects with a history of MTSS, who do not have pain at the time of measurement, and in those without a history of MTSS. The purpose of this study was to compare the shear elastic modulus, which is an index of muscle stiffness, of all posterior lower leg muscles of subjects with a history of MTSS and those with no history and investigate which muscles could be related to MTSS. Twenty-four male collegiate runners (age, 20.0±1.7 years; height, 172.7±4.8 cm; weight, 57.3±3.7 kg) participated in this study; 14 had a history of MTSS, and 10 did not. The shear elastic moduli of the lateral gastrocnemius, medial gastrocnemius, soleus, peroneus longus, peroneus brevis, flexor hallucis longus, flexor digitorum longus, and tibialis posterior were measured using shear wave elastography. The shear elastic moduli of the flexor digitorum longus and tibialis posterior were significantly higher in subjects with a history of MTSS than in those with no history. However, there was no significant difference in the shear elastic moduli of other muscles. The results of this study suggest that flexor digitorum longus and tibialis posterior stiffness could be related to MTSS. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of balance training by knee joint motions on muscle activity in adult men with functional ankle instability.

Science.gov (United States)

Nam, Seung-Min; Kim, Won-Bok; Yun, Chang-Kyo

2016-05-01

[Purpose] This study examined the effects of balance training by applying knee joint movements on muscle activity in male adults with functional ankle instability. [Subjects and Methods] 28 adults with functional ankle instability, divided randomly into an experimental group, which performed balance training by applying knee joint movements for 20 minutes and ankle joint exercises for 10 minutes, and a control group, which performed ankle joint exercise for 30 minutes. Exercises were completed three times a week for 8 weeks. Electromyographic values of the tibialis anterior, peroneus longus, peroneus brevis, and the lateral gastrocnemius muscles were obtained to compare and analyze muscle activity before and after the experiments in each group. [Results] The experimental group had significant increases in muscle activity in the tibialis anterior, peroneus longus, and lateral gastrocnemius muscles, while muscle activity in the peroneus brevis increased without significance. The control group had significant increases in muscle activity in the tibialis anterior and peroneus longus, while muscle activity in the peroneus brevis and lateral gastrocnemius muscles increased without significance. [Conclusion] In conclusion, balance training by applying knee joint movements can be recommended as a treatment method for patients with functional ankle instability.

Peroneus longus tears associated with pathology of the os peroneum.

Science.gov (United States)

Stockton, Kristopher G; Brodsky, James W

2014-04-01

There is a range of different types of tears and pathology of the peroneal tendons. One of the least common types is the tear of the peroneus longus associated with fracture, enlargement, or entrapment at the cuboid tunnel of the os peroneum. The purpose of this study was to evaluate the pathologic patterns of these uncommon peroneal tendon tears, to review the treatment, and to report the patient outcomes following treatment with excision of the os peroneum, debridement, and tenodesis of the peroneus longus to the peroneus brevis. A 5-year retrospective review of all patients with peroneal tendon tears identified 12 patients operatively treated for peroneus longus tendon tears with associated pathology of the os peroneum, and in whom there was a viable peroneus brevis. All patients were treated with an operative procedure consisting of excision of the os peroneum, debridement, and tenodesis of the peroneus longus to the peroneus brevis. Mean age was 51.5 (range, 33 to 73) years, including 7 males and 5 females. Operative and radiographic records were reviewed to characterize the nature of the peroneus longus tears and associated pathology. Preoperative and postoperative AOFAS hindfoot, SF-36 questionnaires, and Visual Analog Scale (VAS) pain scores were compiled and patient records were reviewed for complications. Mean follow-up after surgery was 63.3 (range, 12 to 114) months. All of the patients had an os peroneum associated with a complex, irreparable tear of the peroneus longus tendon. The peroneus longus was typically enlarged, fibrotic, and adhered to the surrounding tissues. In 8 patients, the peroneus longus tendon tear was associated with a fracture of the os peroneum, and in 4 patients with an enlarged and entrapped os peroneum which prevented movement at the cuboid tunnel. Of the 12 patients, 9 had partial tears of the peroneus brevis, which were treated with debridement and suture repair. AOFAS hindfoot scores increased from a preoperative mean of 61

Anatomy of the pectoral and forelimb muscles of wildtype and green fluorescent protein-transgenic axolotls and comparison with other tetrapods including humans: a basis for regenerative, evolutionary and developmental studies

Science.gov (United States)

Diogo, R; Tanaka, E M

2012-01-01

stated in the literature, A. mexicanum has a muscle coracoradialis that has both a well developed proximal fleshy belly and a distal long and thin tendon, supporting the idea that this muscle very likely corresponds to at least part of the amniote biceps brachii. Our observations also: (i) confirmed that the flexores digitorum minimi, interphalangeus digiti 3, pronator quadratus and palmaris profundus 1 are present as distinct muscles in A. mexicanum, supporting the idea that the latter muscle does not correspond to the pronator accessorius of reptiles; (ii) confirmed that the so-called extensor antebrachii radialis is present as a distinct muscle in this species and, importantly, indicated that this muscle corresponds to the supinator of other tetrapods; (iii) showed that, contrary to some other urodeles, including some other Ambystoma species, there is no distinct muscle epitrochleoanconeus in A. mexicanum and; (iv) showed that the ulnar and radial bundles of the abductor et extensor digiti 1 correspond to the abductor pollicis longus and extensor pollicis longus of other tetrapods, respectively. PMID:22957800

Anatomy of the pectoral and forelimb muscles of wildtype and green fluorescent protein-transgenic axolotls and comparison with other tetrapods including humans: a basis for regenerative, evolutionary and developmental studies.

Science.gov (United States)

Diogo, R; Tanaka, E M

2012-12-01

stated in the literature, A. mexicanum has a muscle coracoradialis that has both a well developed proximal fleshy belly and a distal long and thin tendon, supporting the idea that this muscle very likely corresponds to at least part of the amniote biceps brachii. Our observations also: (i) confirmed that the flexores digitorum minimi, interphalangeus digiti 3, pronator quadratus and palmaris profundus 1 are present as distinct muscles in A. mexicanum, supporting the idea that the latter muscle does not correspond to the pronator accessorius of reptiles; (ii) confirmed that the so-called extensor antebrachii radialis is present as a distinct muscle in this species and, importantly, indicated that this muscle corresponds to the supinator of other tetrapods; (iii) showed that, contrary to some other urodeles, including some other Ambystoma species, there is no distinct muscle epitrochleoanconeus in A. mexicanum and; (iv) showed that the ulnar and radial bundles of the abductor et extensor digiti 1 correspond to the abductor pollicis longus and extensor pollicis longus of other tetrapods, respectively. © 2012 The Authors. Journal of Anatomy © 2012 Anatomical Society.

Relative strengths of the calf muscles based on MRI volume measurements.

Science.gov (United States)

Jeng, Clifford L; Thawait, Gaurav K; Kwon, John Y; Machado, Antonio; Boyle, James W; Campbell, John; Carrino, John A

2012-05-01

In 1985, Silver et al. published a cadaver study which determined the relative order of strength of the muscles in the calf. Muscle strength, which is proportional to volume, was obtained by dissecting out the individual muscles, weighing them, and then multiplying by the specific gravity. No similar studies have been performed using {\\it in vivo} measurements of muscle volume. Ten normal subjects underwent 3-Tesla MRI's of both lower extremities using non-fat-saturated T2 SPACE sequences. The volume for each muscle was determined by tracing the muscle contour on sequential axial images and then interpolating the volume using imaging software. The results from this study differ from Silver's original article. The lateral head of the gastrocnemius was found to be stronger than the tibialis anterior muscle. The FHL and EDL muscles were both stronger than the peroneus longus. There was no significant difference in strength between the peroneus longus and brevis muscles. This revised order of muscle strengths in the calf based on in vivo MRI findings may assist surgeons in determining the optimal tendons to transfer in order to address muscle weakness and deformity.

A Rare Cause of Dysphagia to Remember: Calcific Tendinitis of the Longus Colli Muscle

Directory of Open Access Journals (Sweden)

Dominic M. Colella

2016-12-01

Full Text Available Longus colli tendinitis (LCT is an acute inflammatory condition with symptoms typically consisting of acute neck pain and stiffness with or without dysphagia. Once more severe etiologies for these symptoms are ruled out, this self-limiting condition usually resolves spontaneously with nonsteroidal anti-inflammatory drugs and corticosteroids. We present a case of LCT that presented as acute neck pain, dysphagia, and odynophagia that rapidly resolved once diagnosed and treated with anti-inflammatory agents. Though exceedingly rare, LCT must be considered in the differential diagnosis of acute neck pain, dysphagia, and odynophagia when more common etiologies do not correlate with the clinical presentation.

Determining physiological cross-sectional area of extensor carpi radialis longus and brevis as a whole and by regions using 3D computer muscle models created from digitized fiber bundle data.

Science.gov (United States)

Ravichandiran, Kajeandra; Ravichandiran, Mayoorendra; Oliver, Michele L; Singh, Karan S; McKee, Nancy H; Agur, Anne M R

2009-09-01

Architectural parameters and physiological cross-sectional area (PCSA) are important determinants of muscle function. Extensor carpi radialis longus (ECRL) and brevis (ECRB) are used in muscle transfers; however, their regional architectural differences have not been investigated. The aim of this study is to develop computational algorithms to quantify and compare architectural parameters (fiber bundle length, pennation angle, and volume) and PCSA of ECRL and ECRB. Fiber bundles distributed throughout the volume of ECRL (75+/-20) and ECRB (110+/-30) were digitized in eight formalin embalmed cadaveric specimens. The digitized data was reconstructed in Autodesk Maya with computational algorithms implemented in Python. The mean PCSA and fiber bundle length were significantly different between ECRL and ECRB (p < or = 0.05). Superficial ECRL had significantly longer fiber bundle length than the deep region, whereas the PCSA of superficial ECRB was significantly larger than the deep region. The regional quantification of architectural parameters and PCSA provides a framework for the exploration of partial tendon transfers of ECRL and ECRB.

Muscle response to leg lengthening during distraction osteogenesis.

Science.gov (United States)

Thorey, Fritz; Bruenger, Jens; Windhagen, Henning; Witte, Frank

2009-04-01

Continuous lengthening of intact muscles during distraction osteogenesis leads to an increase of sarcomeres and enhances the regeneration of tendons and blood vessels. A high distraction rate leads to an excessive leg and muscle lengthening and might cause damages of muscle fibers with fibrosis, necrosis, and muscle weakness. Complications like muscle contractures or atrophy after postoperative immobilization emphazize the importance of muscles and their function in the clinical outcome. In an animal model of distraction osteogenesis, 18 sheep were operated with an external fixator followed by 4 days latency, 21 days distraction (1.25 mm per day) and 51 days consolidation. The anatomical location (gastrocnemius, peroneus tertius, and first flexor digitorum longus muscle), dimension and occurrence of muscular defects were characterized histologically. The callus formation and leg axis was monitored by weekly X-rays. Additionally, serum creatine kinase was analyzed during a distraction and consolidation period. Significant signs of muscle lesions in all three observed muscles can be found postoperatively, whereas normal callus formation and regular leg axis was observed radiologically. The peroneus tertius and first flexor digitorum longus muscles were found to have significantly more signs of fibrosis, inflammatory, and necrosis. Creatine kinase showed two peaks: 4 and 39 days postoperative as an indication of muscle damage and regeneration. The study implicates that muscle damages should be considered when a long-distance distraction osteogenesis is planned. The surgeon should consider these muscle responses and individually discuss a two-stage treatment or additional muscle tendon releases to minimize the risk of muscle damages.

Arthroscopic procedures and therapeutic results of anatomical reconstruction of the coracoclavicular ligaments for acromioclavicular Joint dislocation.

Science.gov (United States)

Takase, K; Yamamoto, K

2016-09-01

Surgical treatment is recommended for type 5 acromioclavicular joint dislocation on Rockwood's classification. We believe that anatomic repair of the coracoclavicular ligaments best restores the function of the acromioclavicular joint. We attempted to correctly reconstruct the anatomy of the coracoclavicular ligaments under arthroscopy, and describe the minimally invasive arthroscopic procedure. There were 22 patients; mean age at surgery, 38.1 years. Mean time to surgery was 13.2 days. Mean follow-up was 3 years 2 months. The palmaris longus tendon was excised from the ipsilateral side to replace the conoid ligament, while artificial ligament was used for reconstructing the trapezoid ligament. Both ligament reconstructions were performed arthroscopically. No temporary fixation of the acromioclavicular joint was performed. On postoperative radiographic evaluation, 4 patients showed subluxation and 2 showed dislocation of the acromioclavicular joint; the other 16 patients had maintained reduction at the final consultation. MR images 1year after surgery clearly revealed the reconstructed ligaments in 19 patients. Only 1 patient showed osteoarthritis of the acromioclavicular joint. Although it requires resection of the ipsilateral palmaris longus for grafting, we believe that anatomic reconstruction of both coracoclavicular ligaments best restores the function of the acromioclavicular joint. 4. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Direct effects of FGF21 on glucose uptake in human skeletal muscle

DEFF Research Database (Denmark)

Mashili, Fredirick L; Austin, Reginald L; Deshmukh, Atul S

2011-01-01

21 were determined in normal glucose tolerant (n = 40) and type 2 diabetic (T2D; n = 40) subjects. We determined whether FGF21 has direct effects on glucose metabolism in cultured myotubes (n = 8) and extensor digitorum longus skeletal muscle. RESULTS: Serum FGF21 levels increased 20% in T2D versus...... normal glucose tolerant subjects (p muscle mRNA expression was unaltered. Fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), waist circumference, and body mass index (BMI) significantly correlated with serum FGF21 levels in T2D (p ... and insulin-stimulated glucose uptake in human myotubes, coincident with increased glucose transporter 1 mRNA, and enhanced glucose transporter 1 abundance at the plasma membrane. In isolated extensor digitorum longus muscle, FGF21 potentiated insulin-stimulated glucose transport, without altering...

Muscle protein analysis. II. Two-dimensional electrophoresis of normal and diseased human skeletal muscle

Energy Technology Data Exchange (ETDEWEB)

Giometti, C.S. (Argonne National Lab., IL); Barany, M.; Danon, M.J.; Anderson, N.G.

1980-07-01

High-resolution two-dimensional electrophoresis was used to analyze the major proteins of normal and pathological human-muscle samples. The normal human-muscle pattern contains four myosin light chains: three that co-migrate with the myosin light chains from rabbit fast muscle (extensor digitorum longus), and one that co-migrates with the light chain 2 from rabbit slow muscle (soleus). Of seven Duchenne muscular dystrophy samples, four yielded patterns with decreased amounts of actin and myosin relative to normal muscle, while three samples gave patterns comparable to that for normal muscle. Six samples from patients with myotonic dystrophy also gave normal patterns. In nemaline rod myopathy, in contrast, the pattern was deficient in two of the fast-type myosin light chains.

Anatomía arterial de los colgajos musculares de extensor carpi radialis longus y extensor carpi radialis brevis para su uso en transferencia muscular funcional libre Arterial anatomy of the extensor carpi radialis longus and extensor carpi radialis brevis muscle flaps related to its use in free functioning muscle transfer

Directory of Open Access Journals (Sweden)

A. Rodríguez Lorenzo

2008-09-01

ón anatómica del nervio radial con el pedículo del ECRL hace que no sea posible su transferencia como colgajo libre sin sacrificar la rama motora del nervio radial en la mayor parte de los casos.The arterial anatomy of the Extensor Carpi Radialis Longus and Brevis (ECRL, ECRB flaps is herein described in order to provide the vascular basis to be used as free muscle transfer for facial reanimation. We used 29 fresh above-elbow human arms injected by means of two diferent techniques.Latex-injection was performed in 18 arms and the modified lead oxide-gelatine injection technique was performed in 11 arms. The ECRL and ECRB with their pedicles were dissected, photodocumented and radiographied.The number, length and calibers of the muscle pedicles were recorded. The intramuscular vascular pattern and the relations of the main pedicles of the muscles with the radial nerve were also noted. Two vascular patterns were found following the Mathes and Nahai Classification of the Vascular Anatomy of the Muscles (number of pedicles and its dominance: Type I (37,9% of ECRL and 20,7% of ECRB dissections and Type II (62,1% of ECRL and 79,3% of ECRB dissections. The dominant pedicle for the ECRL (with an average caliber of 1,73 mm and an average length of pedicle of 32,32 mm is a branch of the radial recurrent artery in 100% of the dissections and the dominant pedicle for the ECRB (with an average caliber of 1,11 mm and an average length of pedicle of 27,77 mm a branch of the radial artery in 68,9% of the dissections and a branch of radial recurrent artery in 31,1% of the cases. As a conclusion, ECRL and ECRB muscle flaps present two types of vascular patterns: type I and type II.Type II pattern is the most common in our study. The anatomical features of both muscles (vascular basis,presence of an important fascial layer, contour and length of the muscle, make them reliable as free muscles flaps for facial reanimation, however, the relation between the dominant pedicle for the ECRL

Tensile strength comparison between peroneus longus and hamstring tendons: A biomechanical study

Directory of Open Access Journals (Sweden)

Rudy

2017-01-01

Conclusion: The tensile strength of the peroneus longus tendon, which is similar to that of hamstring, gives information that both have the same biomechanic properties. Peroneus longus should not be used as a first option in ACL reconstruction, but may be used as an alternative donor in cases involving multiple instability that require more tendon donors in the reconstruction.

Contributions of foot muscles and plantar fascia morphology to foot posture.

Science.gov (United States)

Angin, Salih; Mickle, Karen J; Nester, Christopher J

2018-03-01

The plantar foot muscles and plantar fascia differ between different foot postures. However, how each individual plantar structure contribute to foot posture has not been explored. The purpose of this study was to investigate the associations between static foot posture and morphology of plantar foot muscles and plantar fascia and thus the contributions of these structures to static foot posture. A total of 111 participants were recruited, 43 were classified as having pes planus and 68 as having normal foot posture using Foot Posture Index assessment tool. Images from the flexor digitorum longus (FDL), flexor hallucis longus (FHL), peroneus longus and brevis (PER), flexor hallucis brevis (FHB), flexor digitorum brevis (FDB) and abductor hallucis (AbH) muscles, and the calcaneal (PF1), middle (PF2) and metatarsal (PF3) regions of the plantar fascia were obtained using a Venue 40 ultrasound system with a 5-13 MHz transducer. In order of decreasing contribution, PF3 > FHB > FHL > PER > FDB were all associated with FPI and able to explain 69% of the change in FPI scores. PF3 was the highest contributor explaining 52% of increases in FPI score. Decreased thickness was associated with increased FPI score. Smaller cross sectional area (CSA) in FHB and PER muscles explained 20% and 8% of increase in FPI score. Larger CSA of FDB and FHL muscles explained 4% and 14% increase in FPI score respectively. The medial plantar structures and the plantar fascia appear to be the major contributors to static foot posture. Elucidating the individual contribution of multiple muscles of the foot could provide insight about their role in the foot posture. Copyright © 2018. Published by Elsevier B.V.

Ultrasound evaluation of foot muscles and plantar fascia in pes planus.

Science.gov (United States)

Angin, Salih; Crofts, Gillian; Mickle, Karen J; Nester, Christopher J

2014-01-01

Multiple intrinsic and extrinsic soft tissue structures that apply forces and support the medial longitudinal arch have been implicated in pes planus. These structures have common functions but their interaction in pes planus is not fully understood. The aim of this study was to compare the cross-sectional area (CSA) and thickness of the intrinsic and extrinsic foot muscles and plantar fascia thickness between normal and pes planus feet. Forty-nine adults with a normal foot posture and 49 individuals with pes planus feet were recruited from a university population. Images of the flexor digitorum longus (FDL), flexor hallucis longus (FHL), peroneus longus and brevis (PER), flexor hallucis brevis (FHB), flexor digitorum brevis (FDB) and abductor hallucis (AbH) muscles and the plantar fascia were obtained using a Venue 40 ultrasound system with a 5-13 MHz transducer. The CSA and thickness of AbH, FHB and PER muscles were significantly smaller (AbH -12.8% and -6.8%, FHB -8.9% and -7.6%, PER -14.7% and -10%), whilst FDL (28.3% and 15.2%) and FHL (24% and 9.8%) were significantly larger in the pes planus group. The middle (-10.6%) and anterior (-21.7%) portions of the plantar fascia were thinner in pes planus group. Greater CSA and thickness of the extrinsic muscles might reflect compensatory activity to support the MLA if the intrinsic foot muscle function has been compromised by altered foot structure. A thinner plantar fascia suggests reduced load bearing, and regional variations in structure and function in feet with pes planus. Copyright © 2014 Elsevier B.V. All rights reserved.

Flexor Digitorum Accessorius Longus: Importance of Posterior Ankle Endoscopy

Directory of Open Access Journals (Sweden)

Jorge Pablo Batista

2015-01-01

Full Text Available Endoscopy for the posterior region of the ankle through two portals is becoming more widespread for the treatment of a large number of conditions which used to be treated with open surgery years ago. The tendon of the flexor hallucis longus (FHL travels along an osteofibrous tunnel between the posterolateral and posteromedial tubercles of the talus. Chronic inflammation of this tendon may lead to painful stenosing tenosynovitis. The aim of this report is to describe two cases depicting an accessory tendon which is an anatomical variation of the flexor hallucis longus in patients with posterior friction syndrome due to posterior ankle impingement and associated with a posteromedial osteochondral lesion of the talus. The anatomical variation (FDAL described was a finding during an endoscopy of the posterior region of the ankle, and we have spared it by sectioning the superior flexor retinaculum only. The accessory flexor digitorum longus is an anatomical variation and should be taken into account when performing an arthroscopy of the posterior region of the ankle. We recommend this treatment on this type of injury although we admit this does not make a definite conclusion.

Musculoskeletal management of a patient with a history of chronic ankle sprains: identifying rupture of peroneal brevis and peroneal longus with diagnostic ultrasonography.

Science.gov (United States)

Bruin, Dick B; von Piekartz, Harry

2014-09-01

The purpose of this case report is to describe the use of mobilization and eccentric exercise training for a patient with ankle pain and a history of chronic ankle sprains and discuss the course of diagnostic decision making when the patient did not respond to care. A 48-year-old police officer who had sustained multiple ankle sprains throughout his life presented with pain and restriction in his ability to walk, run, and work. The Global Rating of Change Scale score was - 6, the Numeric Pain Rating Scale score was 7/10, and the Lower Extremity Functional Scale score was - 33. Palpation of the peroneus longus and brevis muscles and inversion with overpressure reproduced the chief concern (Numeric Pain Rating Scale 7/10). The patient was initially diagnosed with chronic peroneal tendinopathy. Treatment included lateral translation mobilization of the talocrural joint combined with eccentric exercise using an elastic band for the peroneal muscles. The patient reported improvement in pain and function during the course of intervention but not as rapidly as expected. Therefore, follow-up ultrasonographic imaging and radiography were performed. These studies revealed partial rupture of the peroneal brevis muscle and total rupture of the peroneal longus muscle. A patient with long-term concerns of the foot complex with a diagnosis of peroneal tendinopathy showed slight improvement with eccentric exercises combined with manual therapy of the talocrural joint. After a course of treatment but minimal response, a diagnosis of tendon rupture was confirmed with diagnostic ultrasonography. Clinicians should be aware that when injuries do not improve with care, tendon rupture should be considered.

Extending the use of the gracilis muscle flap in perineal reconstruction surgery.

Science.gov (United States)

Goldie, Stephen J; Almasharqah, Riyadh; Fogg, Quentin A; Anderson, William

2016-08-01

Reconstruction of the perineum is required following oncological resections. Plastic surgical techniques can be used to restore the aesthetics and function of the perineum. The gracilis myocutaneous flap provides a substantial skin paddle, with minimal donor site morbidity. The flap is pedicled on a perforator from the medial circumflex femoral artery, giving it limited reach across the perineum. Tunnelling the flap under the adductor longus muscle may free up more of the arterial pedicle, increasing its reach. On three female cadavers, bilateral gracilis flaps were raised in the standard surgical manner, giving six flaps in total. With the flaps pedicled across the perineum, the distance from the tip of each flap was measured to the anterior superior iliac spine (ASIS). The flaps were then tunnelled under the adductor longus muscle. The distances to the ASIS were measured again. The average pedicle length was greater than 7 cm. Tunnelling the flap under the adductor longus muscle increased the reach by more than 4 cm on average. Cadaveric dissection has shown that tunnelling of the flap in a novel way increase its reach across the perineum. This additional flexibility improves its use clinically and is of benefit to plastic surgeons operating in perineal reconstruction. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Calcifications simulating peroneus longus tendinitis

International Nuclear Information System (INIS)

Carvalho, A. de; Illum, F.; Joergensen, J.

1984-01-01

In two patients with sprains of the ankle joint calcification adjacent to the posterior tibial margin was evident in the lateral projection of a standard radiographic examination. Calcifying peroneus longus tendinitis was suggested. Further tangential views and computed tomography (CT) scan disclosed, however, that the calcifications in both patients were located in the tibial insertion of the posterior and inferior tibio-fibular ligament. In such cases, a correct diagnosis will avoid unnecessary treatment for a non-existent tendinitis. (orig.)

Advantages of externally powered prosthesis with feedback system using pseudo-cineplasty.

Science.gov (United States)

Nambu, Seiji; Ikebuchi, Mitsuhiko; Taniguchi, Masashi; Park, Choong Sik; Kitagawa, Takahiro; Nakajima, Shigeyoshi; Koike, Tatsuya

2014-01-01

Externally powered upper-limb prostheses are difficult to use because of the lack of sensory feedback. Neuroprostheses have recently been developed for people with upper-limb amputation but are complicated, expensive, and still developing. We therefore designed a simple system by combining pseudo-cineplasty with extended physiological proprioception to provide sensory feedback to the body. We penetrated the palmaris longus tendon percutaneously with a metal ring, similar to that used in body piercing, in a nondisabled subject as a pseudo-cineplasty. The tendon and ring were connected to the system, and a sensory feedback experiment was performed. We investigated the ability of the user to determine the size of an object grasped by the prosthetic hand without visual information. The subject could distinguish between large and small objects with 100% accuracy and between small, medium, and large objects with 80% accuracy. In pseudo-cineplasty, control and sensory feedback are natural because the prosthetic hand is controlled by muscle contraction. Tension transmitted from the prosthetic hand is sensed via muscle spindles and skin sensors. This technique allows only partial sensory feedback but appears to offer several advantages over other human-machine interfaces.

Evaluation of clinical methods for peroneal muscle testing.

Science.gov (United States)

Sarig-Bahat, Hilla; Krasovsky, Andrei; Sprecher, Elliot

2013-03-01

Manual muscle testing of the peroneal muscles is well accepted as a testing method in musculoskeletal physiotherapy for the assessment of the foot and ankle. The peroneus longus and brevis are primary evertors and secondary plantar flexors of the ankle joint. However, some international textbooks describe them as dorsi flexors, when instructing peroneal muscle testing. The identified variability raised a question whether these educational texts are reflected in the clinical field. The purposes of this study were to investigate what are the methods commonly used in the clinical field for peroneal muscle testing and to evaluate their compatibility with functional anatomy. A cross-sectional study was conducted, using an electronic questionnaire sent to 143 Israeli physiotherapists in the musculoskeletal field. The survey questioned on the anatomical location of manual resistance and the combination of motions resisted. Ninety-seven responses were received. The majority (69%) of respondents related correctly to the peronei as evertors, but asserted that resistance should be located over the dorsal aspect of the fifth metatarsus, thereby disregarding the peroneus longus. Moreover, 38% of the respondents described the peronei as dorsi flexors, rather than plantar flexors. Only 2% selected the correct method of resisting plantarflexion and eversion at the base of the first metatarsus. We consider this technique to be the most compatible with the anatomy of the peroneus longus and brevis. The Fisher-Freeman-Halton test indicated that there was a significant relationship between responses on the questions (P = 0.0253, 95% CI 0.0249-0.0257), thus justifying further correspondence analysis. The correspondence analysis found no clustering of the answers that were compatible with anatomical evidence and were applied in the correct technique, but did demonstrate a common error, resisting dorsiflexion rather than plantarflexion, which was in agreement with the described

Are Ultrasonographic Measures of Cervical Flexor Muscles Correlated With Flexion Endurance in Chronic Neck Pain and Asymptomatic Participants?

Science.gov (United States)

Ghamkhar, Leila; Kahlaee, Amir Hossein

2017-12-01

This study compared the relationship between some clinical factors and the size of neck flexors in participants with or without chronic neck pain. In this case-control study, the correlation between flexor endurance capacity as well as thickness, cross-section area, and shape ratio of longus colli/capitis and sternocleidomastoid muscles were examined in 30 patients with chronic neck pain and 30 asymptomatic participants. The patients showed lower flexor endurance (P = 0.02), smaller thickness (P = 0.03), and cross-section area (P pain. In the control group, flexor endurance was negatively correlated with longus colli shape ratio (r = -0.45, P = 0.01) but positively correlated with longus capitis thickness (r = 0.45, P = 0.01) and cross-section area (r = 0.38, P = 0.03). Neck disability and pain intensity indices were not significantly correlated with either flexor muscles endurance or size. The ultrasonographic measures of the deep neck flexor muscles and the flexor endurance test, being associated with each other, could successfully differentiate patients with chronic neck pain from asymptomatic participants. However, the endurance test scores were not correlated with self-reported disability or pain intensity indices.

Protein degradation in skeletal muscle during experimental hyperthyroidism in rats and the effect of beta-blocking agents.

Science.gov (United States)

Angerås, U; Hasselgren, P O

1987-04-01

beta-Blocking agents are increasingly used in the management of hyperthyroid patients. The effect of this treatment on increased muscle protein breakdown in the hyperthyroid state is not known. In the present study, experimental hyperthyroidism was induced in rats by daily ip injections of T3 (100 micrograms/100 g BW) during a 10-day period. Control animals received corresponding volumes of solvent. In groups of rats the selective beta-1-blocking agent metoprolol or the nonselective beta-blocker propranolol was infused by miniosmotic pumps implanted sc on the backs of the animals. Protein degradation was measured in incubated intact soleus and extensor digitorum longus muscles by determining tyrosine release into the incubation medium. The protein degradation rate in incubated extensor digitorum longus and soleus muscles was increased by 50-60% during T3 treatment. Metoprolol or propranolol did not influence muscle protein breakdown in either T3-treated or control animals. The results suggest that T3-induced increased muscle proteolysis is not mediated by beta-receptors, and muscle weakness and wasting in hyperthyroidism might not be affected by beta-blockers.

Muscle Reaction Time During a Simulated Lateral Ankle Sprain After Wet-Ice Application or Cold-Water Immersion.

Science.gov (United States)

Thain, Peter K; Bleakley, Christopher M; Mitchell, Andrew C S

2015-07-01

Cryotherapy is used widely in sport and exercise medicine to manage acute injuries and facilitate rehabilitation. The analgesic effects of cryotherapy are well established; however, a potential caveat is that cooling tissue negatively affects neuromuscular control through delayed muscle reaction time. This topic is important to investigate because athletes often return to exercise, rehabilitation, or competitive activity immediately or shortly after cryotherapy. To compare the effects of wet-ice application, cold-water immersion, and an untreated control condition on peroneus longus and tibialis anterior muscle reaction time during a simulated lateral ankle sprain. Randomized controlled clinical trial. University of Hertfordshire human performance laboratory. A total of 54 physically active individuals (age = 20.1 ± 1.5 years, height = 1.7 ± 0.07 m, mass = 66.7 ± 5.4 kg) who had no injury or history of ankle sprain. Wet-ice application, cold-water immersion, or an untreated control condition applied to the ankle for 10 minutes. Muscle reaction time and muscle amplitude of the peroneus longus and tibialis anterior in response to a simulated lateral ankle sprain were calculated. The ankle-sprain simulation incorporated a combined inversion and plantar-flexion movement. We observed no change in muscle reaction time or muscle amplitude after cryotherapy for either the peroneus longus or tibialis anterior (P > .05). Ten minutes of joint cooling did not adversely affect muscle reaction time or muscle amplitude in response to a simulated lateral ankle sprain. These findings suggested that athletes can safely return to sporting activity immediately after icing. Further evidence showed that ice can be applied before ankle rehabilitation without adversely affecting dynamic neuromuscular control. Investigation in patients with acute ankle sprains is warranted to assess the clinical applicability of these interventions.

The Effects of Long-Term Experimental Diabetes Mellitus Type I on Skeletal Muscle Regeneration Capacity

OpenAIRE

Jerković, Romana; Bosnar, Alan; Jurišić-Eržen, Dubravka; Ažman, Josip; Starčević-Klasan, Gordana; Peharec, Stanislav; Čoklo, Miran

2009-01-01

Muscle fibers are dynamic structures capable of altering their phenotype under various pathological conditions. The aim of the present study was to investigate the influence of long-lasting diabetes mellitus on the process of muscle regeneration in the skeletal muscle. Wistar rats were made diabetic by a single intraperitoneal injection of streptozotocin (STZ). The regeneration process in the skeletal muscle was induced in slow (m. soleus, SOL) and fast (m. extensor digitorum longus, EDL) mus...

Spontaneous Rupture of the Extensor Pollicis Longus Tendon due to Unusual Etiology

Directory of Open Access Journals (Sweden)

Süleyman Taş

2014-03-01

Full Text Available Background: The etiology of spontaneous rupture of the extensor pollicis longus tendon includes systemic or local steroid injections, wrist fracture, tenosynovitis, synovitis, rheumatoid arthritis, and repetitive wrist motions. Case Report: We encountered a case of extensor pollicis longus tendon rupture with an unusual etiology, cow milking. In this case, transfer of the extensor indicis proprius tendon was performed successfully. At 1 year after surgery, extension of the thumb was sufficient. Conclusion: It appears that patients with occupations involving repetitive motions are at a high risk of closed tendon ruptures.

Anatomical variation of radial wrist extensor muscles: a study in cadavers

Directory of Open Access Journals (Sweden)

Soubhagya Ranjan Nayak

2008-01-01

Full Text Available OBJECTIVE: The tendons of the extensor carpi radialis longus and brevis muscles are quite useful in tendon transfer, such as in correction of finger clawing and restoration of thumb opposition. Knowledge of additional radial wrist extensor muscle bellies with independent tendons is useful in the above-mentioned surgical procedures. METHODS: The skin, subcutaneous tissue, and antebrachial fascia of 48 (24 on the right side and 24 on left side male upper limb forearms were dissected. The following aspects were then analyzed: (a the presence of additional muscle bellies of radial wrist extensors, (b the origin and insertion of the additional muscle, and (c measurements of the muscle bellies and their tendons. RESULTS: Five out of 48 upper limbs (10.41% had additional radial wrist extensors; this occurred in 3 out of 24 left upper limbs (12.5% and 2 out of 24 right upper limbs (8.3%. In one of the right upper limbs, two additional muscles were found. The length and width of each additional muscle belly and its tendon ranged between 2 - 15cm by 0.35 - 6.4cm and 2.8 - 20.8cm by 0.2 0.5cm, respectively. The additional radial wrist extensor tendons in our study basically originated either from the extensor carpi radialis longus or brevis muscles and were inserted at the base of the 2nd or 3rd metacarpal bone. CONCLUSION: The present study will inform surgeons about the different varieties of additional radial wrist extensors and the frequency of their occurrence.

Improvement of pustulosis palmaris et plantaris by periodontal infection control in a patient with chronic periodontitis.

Science.gov (United States)

Murai, Osamu; Sasaki, Daisuke; Ando, Yoshinori; Fujimura, Akira; Oikawa, Hiromi; Suwa, Nagisa; Watabe, Daisuke; Maeda, Fumihiko; Endo, Kohki; Yaegashi, Takashi; Akasaka, Toshihide; Naruishi, Koji

2012-01-01

Pustulosis palmaris et plantaris (PPP) is a chronic, inflammatory, autoimmune-type disease characterized by sterile pustules of skin. The skin inflammation is influenced by several factors such as drugs, sunlight, metabolic and psychogenic factors as well as metal allergy. Here, we report a rare case that intensive periodontal treatment might have contributed to the improvement of skin inflammation. Skin inflammation regressed 1 month after intensive periodontal treatment. Both CD4/CD8 ratio and % of B cells in the blood sample were slightly decreased corresponding to the improvement of periodontal inflammation. Infection control of periodontal lesions might be one of attractive therapeutic targets in management of PPP.

Muscle activity of leg muscles during unipedal stance on therapy devices with different stability properties.

Science.gov (United States)

Wolburg, Thomas; Rapp, Walter; Rieger, Jochen; Horstmann, Thomas

2016-01-01

To test the hypotheses that less stable therapy devices require greater muscle activity and that lower leg muscles will have greater increases in muscle activity with less stable therapy devices than upper leg muscles. Cross-sectional laboratory study. Laboratory setting. Twenty-five healthy subjects. Electromyographic activity of four lower (gastrocnemius medialis, soleus, tibialis anterior, peroneus longus) and four upper leg muscles (vastus medialis and lateralis, biceps femoris, semitendinosus) during unipedal quiet barefoot stance on the dominant leg on a flat rigid surface and on five therapy devices with varying stability properties. Muscle activity during unipedal stance differed significantly between therapy devices (P < 0.001). The order from lowest to highest relative muscle activity matched the order from most to least stable therapy device. There was no significant interaction between muscle location (lower versus upper leg) and therapy device (P = 0.985). Magnitudes of additional relative muscle activity for the respective therapy devices differed substantially among lower extremity muscles. The therapy devices offer a progressive increase in training intensity, and thus may be useful for incremental training programs in physiotherapeutic practice and sports training programs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Anatomical Study of the Neurovascular in Flexor Hallucis Longus Tendon Transfers.

Science.gov (United States)

Mao, Haijiao; Dong, Wenwei; Shi, Zengyuan; Yin, Weigang; Xu, Dachuan; Wapner, Keith L

2017-10-27

The transfer of the flexor hallucis longus tendon or flexor digitorum longus tendon is frequently used for the treatment of posterior tibial tendon insufficiency or chronic Achilles tendinopathy. According to several anatomical studies, harvesting the flexor hallucis longus (FHL) tendon may cause nerve injury. Sixty-eight embalmed feet were dissected and anatomically classified to define the relationship between Henry's knot and the plantar nerves. Two different configurations were identified. In Pattern 1, which was observed in 64 specimens (94.1%), the distance between the medial plantar nerve and Henry's knot was 5.96 mm (range, 3.34 to 7.84, SD = 1.12). In Pattern 2, which was observed in 4 specimens (5.9%), there was no distance between the medial plantar nerve (MPN) and Henry's knot. No statistically significant difference was observed according to gender or side (p > 0.05). A retraction was performed to harvest the FHL through the posteromedial hindfoot incision using a single minimally invasive technique, and the medial and lateral plantar nerve lesions were scrupulously assessed. In conclusion, medial and lateral plantar nerve injuries did not occur more frequently, even after performing a single minimally invasive incision to harvest the FHL tendon, due to the large distance between the FHL tendon and the medial and lateral plantar nerves.

Patellar stabilization: a quantitative evaluation of the vastus medialis obliquus muscle

NARCIS (Netherlands)

Raimondo, R. A.; Ahmad, C. S.; Blankevoort, L.; April, E. W.; Grelsamer, R. P.; Henry, J. H.

1998-01-01

Twenty-one cadaveric knees were dissected to analyze the functional anatomy of the vastus medialis complex (VMC), which is composed of the vastus medialis obliquus (VMO) and the vastus medialis longus (VML) muscles. The physiologic cross-sectional area of the VMO for 20 of the knees was 29% of the

Is dermatitis palmaris sicca an irritant contact dermatitis?

Science.gov (United States)

Chen, Fu-Juan; Liu, Zhen; Zhou, Ying; Chen, Yong-Hua; Fan, Yi-Ming

2013-01-01

Dermatitis palmaris sicca (DPS) is a common dry-fissured palmar dermatitis in Asian women. It may be an irritant contact dermatitis, but the immunophenotype of the cells in its infiltrate is unknown. The aim of this study was to evaluate the role of inflammatory cells in the pathogenesis of DPS. Patch testing was done in 68 patients with DPS, 87 subjects with hand eczema, and 31 healthy subjects. Immunophenotyping of cutaneous inflammatory cells was performed in 8 patients with DPS, 10 subjects with hand eczema, and 8 healthy individuals. Positive patch rates were higher in patients with DPS and those with hand eczema compared with healthy controls, but strong positive (++ or +++) reactions in DPS were fewer compared with hand eczema. Density of CD3, CD4, CD8, and CD68 cells in skin lesions of DPS and hand eczema was significantly higher than that in normal skin. Sparse CD20 cells were present only in hand eczema. Compared with hand eczema, the number of CD3, CD8, CD68, and dermal CD1a cells decreased, but epidermal CD1a cells and CD4/CD8 ratio increased in DPS. The absolute lack of CD20 cells and relative scarcity of dermal CD8 and CD1a cells in skin lesions might be insufficient to induce contact hypersensitivity, so DPS may be an irritant but not allergic contact dermatitis.

Energy conservation attenuates the loss of skeletal muscle excitability during intense contractions

DEFF Research Database (Denmark)

Macdonald, W A; Ørtenblad, N; Nielsen, Ole Bækgaard

2007-01-01

High-frequency stimulation of skeletal muscle has long been associated with ionic perturbations, resulting in the loss of membrane excitability, which may prevent action potential propagation and result in skeletal muscle fatigue. Associated with intense skeletal muscle contractions are large...... with control muscles, the resting metabolites ATP, phosphocreatine, creatine, and lactate, as well as the resting muscle excitability as measured by M-waves, were unaffected by treatment with BTS plus dantrolene. Following 20 or 30 s of continuous 60-Hz stimulation, BTS-plus-dantrolene-treated muscles showed...... changes in muscle metabolites. However, the role of metabolites in the loss of muscle excitability is not clear. The metabolic state of isolated rat extensor digitorum longus muscles at 30 degrees C was manipulated by decreasing energy expenditure and thereby allowed investigation of the effects of energy...

Facilitation of Hoffmann reflexes of ankle muscles in prone but not standing positions by focal ankle-joint cooling.

Science.gov (United States)

Kim, Kyung-Min; Ingersoll, Christopher D; Hertel, Jay

2015-05-01

Focal ankle-joint cooling (FAJC) has been shown to increase Hoffmann (H) reflex amplitudes of select leg muscles while subjects lie prone, but it is unknown whether the neurophysiological cooling effects persist in standing. To assess the effects of FAJC on H-reflexes of the soleus and fibularis longus during 3 body positions (prone, bipedal, and unipedal stances) in individuals with and without chronic ankle instability (CAI). Crossover. Laboratory. 15 young adults with CAI (9 male, 6 female) and 15 healthy controls. All subjects received both FAJC and sham treatments on separate days in a randomized order. FAJC was accomplished by applying a 1.5-L plastic bag filled with crushed ice to the ankle for 20 min. Sham treatment involved room-temperature candy corn. Maximum amplitudes of H-reflexes and motor (M) waves were recorded while subjects lay prone and then stood in quiet bipedal and unipedal stances before and immediately after each treatment. Primary outcome measures were H(max):M(max) ratios for the soleus and fibularis longus. Three-factor (group × treatment condition × time) repeated-measures ANOVAs and Fisher LSD tests were performed for statistical analyses. Significant interactions of treatment condition by time for prone H(max):M(max) ratios were found in the soleus (P = .001) and fibularis longus (P = .003). In both muscles, prone H(max):M(max) ratios moderately increased after FAJC but not after sham treatment. The CAI and healthy groups responded similarly to FAJC. In contrast, there were no significant interactions or main effects in the bipedal and unipedal stances in either muscle (P > .05). FAJC moderately increased H-reflex amplitudes of the soleus and fibularis longus while subjects were prone but not during bipedal or unipedal standing. These results were not different between groups with and without CAI.

Variant insertion of the fibularis tertius muscle is an evidence of the progressive evolutionary adaptation for the bipedal gait

Directory of Open Access Journals (Sweden)

Rashmoni Jana

2011-10-01

Full Text Available Fibularis tertius (FT is often considered as part of extensor digitorum longus (EDL muscle. The muscle is absent in hominoid apes and with the acquisition of the bipedal gait; the muscle emerged as a recent addition in the human foot. From its various modes of insertions, it is evident that the muscles of the sole are in search of its distal attachment, which can best support the relatively weak human midfoot. We describe an unusual insertion of the muscle in support of this hypothesis.

Motor-neuron pool excitability of the lower leg muscles after acute lateral ankle sprain.

Science.gov (United States)

Klykken, Lindsey W; Pietrosimone, Brian G; Kim, Kyung-Min; Ingersoll, Christopher D; Hertel, Jay

2011-01-01

Neuromuscular deficits in leg muscles that are associated with arthrogenic muscle inhibition have been reported in people with chronic ankle instability, yet whether these neuromuscular alterations are present in individuals with acute sprains is unknown. To compare the effect of acute lateral ankle sprain on the motor-neuron pool excitability (MNPE) of injured leg muscles with that of uninjured contralateral leg muscles and the leg muscles of healthy controls. Case-control study. Laboratory. Ten individuals with acute ankle sprains (6 females, 4 males; age= 19.2 ± 3.8 years, height= 169.4 ± 8.5 cm, mass= 66.3 ± 11.6 kg) and 10 healthy individuals(6 females,4 males; age= 20.6 ± 4.0 years, height = 169.9 ± 10.6 cm, mass= 66.3 ± 10.2 kg) participated. The independent variables were group (acute ankle sprain, healthy) and limb (injured, uninjured). Separate dependent t tests were used to determine differences in MNPE between legs. The MNPE of the soleus, fibularis longus, and tibialis anterior was measured by the maximal Hoffmann reflex (H(max)) and maximal muscle response (M(max)) and was then normalized using the H(max):M(max) ratio. The soleus MNPE in the ankle-sprain group was higher in the injured limb (H(max):M(max) = 0.63; 95% confidence interval [Cl],0.46, 0.80) than the uninjured limb (H(max):M(max) = 0.47; 95%Cl, 0.08, 0.93)(t(6) = 3.62,P =.01).In the acute ankle-sprain group, tibialis anterior MNPE tended to be lower in the injured ankle (H(max):M(max) =0.06; 95% Cl, 0.01, 0.10) than in the uninjured ankle (H(max):M(max) =0.22; 95%Cl, 0.09, 0.35),but this finding was not different (t(9) =-2.01, P =.07). No differences were detected between injured (0.22; 95% Cl, 0.14, 0.29) and uninjured (0.25; 95%Cl, 0.12, 0.38) ankles for the fibularis longus in the ankle-sprain group (t(9) =-0.739, P =.48). We found no side-to-side differences in any muscle among the healthy group. Facilitated MNPE was present in the involved soleus muscle of patients with acute

Comparative anatomy and muscle architecture of selected hind limb muscles in the Quarter Horse and Arab.

Science.gov (United States)

Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wakeling, J M; Wilson, A M; Payne, R C

2008-02-01

The Quarter Horse (bred for acceleration) and the Arab (bred for endurance) are situated at either end of the equine athletic spectrum. Studies into the form and function of the leg muscles in human sprint and endurance runners have demonstrated that differences exist in their muscle architecture. It is not known whether similar differences exist in the horse. Six Quarter Horse and six Arab fresh hind limb cadavers were dissected to gain information on the muscle mass and architecture of the following muscles: gluteus medius; biceps femoris; semitendinosus; vastus lateralis; gastrocnemius; tibialis cranialis and extensor digitorum longus. Specifically, muscle mass, fascicle length and pennation angle were quantified and physiological cross-sectional area (PCSA) and maximum isometric force were estimated. The hind limb muscles of the Quarter Horse were of a significantly greater mass, but had similar fascicle lengths and pennation angles when compared with those of the Arab; this resulted in the Quarter Horse hind limb muscles having greater PCSAs and hence greater isometric force potential. This study suggests that Quarter Horses as a breed inherently possess large strong hind limb muscles, with the potential to accelerate their body mass more rapidly than those of the Arab.

MRI of the tibioastragalus anticus of Gruber muscle: a rare accessory muscle and normal anatomical variant

Energy Technology Data Exchange (ETDEWEB)

Berkowitz, Yaron; Amiras, Dimitri [Imperial College Healthcare NHS Trust, London (United Kingdom); St Mary' s Hospital, Imaging Department, QEQM, London (United Kingdom); Mushtaq, Nadeem [Imperial College Healthcare NHS Trust, London (United Kingdom)

2016-06-15

We present the case of a 31-year-old man who sustained a hyperplantar flexion injury of his right ankle, and was evaluated using computed tomography and MRI to assess for osseous and ligamentous injury. The MRI and CT studies demonstrated a tibioastragalus anticus of Gruber (TAAG) muscle in the lower limb's anterior compartment. To our knowledge, the imaging of this muscle has not been previously described. The TAAG muscle arises from the lower third of the anterolateral tibia and the interosseous membrane. Its tendon passes laterally, deep to the tibialis anterior and extensor hallucis longus tendons, and inserts onto the anterior superolateral neck of the talus in a fan-like manner. Knowledge and recognition of this tendon are important for both diagnostic accuracy and surgical planning, and could potentially be used as a tendon transfer or graft in the appropriate clinical setting. The presence of this accessory muscle should not be confused with a pathological condition. (orig.)

Spontaneous atraumatic extensor pollicis longus rupture in the nonrheumatoid population.

Science.gov (United States)

Rada, Erin M; Shridharani, Sachin M; Lifchez, Scott D

2013-01-01

Extensor pollicis longus (EPL) tendon rupture is a well-described phenomenon in patients with rheumatoid arthritis. Mechanisms of EPL tendon rupture in the nonrheumatoid population have also been described and include traumatic rupture, repetitive motion strain, and steroid injection into the tendon. The operative records for patients undergoing extensor pollicis longus reconstruction by the senior author were reviewed. Patients with a history of trauma to the wrist or inflammatory arthropathy were excluded. We identified 3 patients who presented with spontaneous EPL tendon rupture. These patients reported no risk factors (as listed earlier) or inciting event. All 3 patients had some exposure to local steroids but this exposure was not at the site of subsequent tendon rupture. All patients were operatively repaired and went on to full recovery of EPL function. In patients with sudden loss of extension of the thumb interphalangeal joint, a thorough history of steroid exposure including local steroid exposure remote to the affected EPL tendon may be relevant.

Neuromuscular partitioning in the extensor carpi radialis longus and brevis based on intramuscular nerve distribution patterns: A three-dimensional modeling study.

Science.gov (United States)

Ravichandiran, Mayoorendra; Ravichandiran, Nisanthini; Ravichandiran, Kajeandra; McKee, Nancy H; Richardson, Denyse; Oliver, Michele; Agur, Anne M

2012-04-01

Differential activation of specific regions within a skeletal muscle has been linked to the presence of neuromuscular compartments. However, few studies have investigated the extra- or intramuscular innervation throughout the muscle volume of extensor carpi radialis longus (ECRL) and brevis (ECRB). The aim of this study was to determine the presence of neuromuscular partitions in ECRL and ECRB based on the extra- and intramuscular innervation using three-dimensional modeling. The extra- and intramuscular nerve distribution was digitized and reconstructed in 3D in all the muscle volumes using Autodesk Maya in seven formalin embalmed cadaveric specimens (mean age, 75.7 ± 15.2 years). The intramuscular nerve distribution was modeled in all the muscle volumes. ECRL was found to have two neuromuscular compartments, superficial and deep. One branch from the radial nerve proper was found to innervate ECRL. This branch was divided into anterior and posterior branches to the superficial and deep compartments, respectively. Five innervation patterns were identified in ECRB with partitioning of the muscle belly into two, three, or four compartments, in a proximal to distal direction depending on the number of nerve branches entering the muscle belly. The ECRL and ECRB both demonstrated neuromuscular compartmentalization based on intramuscular innervation. According to the partitioning hypothesis, a muscle may be differentially activated depending on the required function of the muscle, thus allowing multifunctional muscles to contribute to a variety of movements. Therefore, the increased number of neuromuscular partitions in ECRB when compared with ECRL could be due to the need for more differential recruitment in the ECRB depending on force requirements. Copyright © 2011 Wiley Periodicals, Inc.

Three-Dimensional Muscle Architecture and Comprehensive Dynamic Properties of Rabbit Gastrocnemius, Plantaris and Soleus: Input for Simulation Studies.

Science.gov (United States)

Siebert, Tobias; Leichsenring, Kay; Rode, Christian; Wick, Carolin; Stutzig, Norman; Schubert, Harald; Blickhan, Reinhard; Böl, Markus

2015-01-01

The vastly increasing number of neuro-muscular simulation studies (with increasing numbers of muscles used per simulation) is in sharp contrast to a narrow database of necessary muscle parameters. Simulation results depend heavily on rough parameter estimates often obtained by scaling of one muscle parameter set. However, in vivo muscles differ in their individual properties and architecture. Here we provide a comprehensive dataset of dynamic (n = 6 per muscle) and geometric (three-dimensional architecture, n = 3 per muscle) muscle properties of the rabbit calf muscles gastrocnemius, plantaris, and soleus. For completeness we provide the dynamic muscle properties for further important shank muscles (flexor digitorum longus, extensor digitorum longus, and tibialis anterior; n = 1 per muscle). Maximum shortening velocity (normalized to optimal fiber length) of the gastrocnemius is about twice that of soleus, while plantaris showed an intermediate value. The force-velocity relation is similar for gastrocnemius and plantaris but is much more bent for the soleus. Although the muscles vary greatly in their three-dimensional architecture their mean pennation angle and normalized force-length relationships are almost similar. Forces of the muscles were enhanced in the isometric phase following stretching and were depressed following shortening compared to the corresponding isometric forces. While the enhancement was independent of the ramp velocity, the depression was inversely related to the ramp velocity. The lowest effect strength for soleus supports the idea that these effects adapt to muscle function. The careful acquisition of typical dynamical parameters (e.g. force-length and force-velocity relations, force elongation relations of passive components), enhancement and depression effects, and 3D muscle architecture of calf muscles provides valuable comprehensive datasets for e.g. simulations with neuro-muscular models, development of more realistic muscle models, or

Three-Dimensional Muscle Architecture and Comprehensive Dynamic Properties of Rabbit Gastrocnemius, Plantaris and Soleus: Input for Simulation Studies.

Directory of Open Access Journals (Sweden)

Tobias Siebert

Full Text Available The vastly increasing number of neuro-muscular simulation studies (with increasing numbers of muscles used per simulation is in sharp contrast to a narrow database of necessary muscle parameters. Simulation results depend heavily on rough parameter estimates often obtained by scaling of one muscle parameter set. However, in vivo muscles differ in their individual properties and architecture. Here we provide a comprehensive dataset of dynamic (n = 6 per muscle and geometric (three-dimensional architecture, n = 3 per muscle muscle properties of the rabbit calf muscles gastrocnemius, plantaris, and soleus. For completeness we provide the dynamic muscle properties for further important shank muscles (flexor digitorum longus, extensor digitorum longus, and tibialis anterior; n = 1 per muscle. Maximum shortening velocity (normalized to optimal fiber length of the gastrocnemius is about twice that of soleus, while plantaris showed an intermediate value. The force-velocity relation is similar for gastrocnemius and plantaris but is much more bent for the soleus. Although the muscles vary greatly in their three-dimensional architecture their mean pennation angle and normalized force-length relationships are almost similar. Forces of the muscles were enhanced in the isometric phase following stretching and were depressed following shortening compared to the corresponding isometric forces. While the enhancement was independent of the ramp velocity, the depression was inversely related to the ramp velocity. The lowest effect strength for soleus supports the idea that these effects adapt to muscle function. The careful acquisition of typical dynamical parameters (e.g. force-length and force-velocity relations, force elongation relations of passive components, enhancement and depression effects, and 3D muscle architecture of calf muscles provides valuable comprehensive datasets for e.g. simulations with neuro-muscular models, development of more realistic

Volume estimation of extensor muscles of the lower leg based on MR imaging

International Nuclear Information System (INIS)

Lund, Hans; Christensen, Line; Savnik, Anette; Danneskiold-Samsoee, Bente; Bliddal, Henning; Boesen, Jens

2002-01-01

Magnetic resonance imaging can be used to measure the muscle volume of a given muscle or muscle group. The purpose of this study was to determine both the intra- and inter-observer variation of the manually outlined volume of the extensor muscles (tibialis anterior, extensor digitorum longus and extensor hallucis longus), to estimate the minimum number of slices needed for these calculations and to compare estimates of volume based on an assumed conic shape of the muscles with that of an assumed cylindrical shape, the calculation in both cases based on the Cavalieri principle. Eleven young and healthy subjects (4 women and 7 men, age range 24-40 years) participated. Magnetic resonance imaging of the left leg was obtained on a 1.5-T MR system using a knee coil (receive only). A total of 50 consecutive slices were obtained beginning 10 cm below the caput fibula sin. and proceeding distally with a slice thickness of 1.5 mm without gap. The intra-class correlation coefficient (ICC) was used to calculate the relative reliability (interval from 0 to 1.0). A high reliability for both intra- and inter-reliability was observed (ICC 0.98 and 1.0). The difference was only 0.004% between calculations based on measurement of all 50 slices with respect to 8 slices equally distributed along the muscle group. No difference was found between the two different volumetric assumptions in the Cavalieri principle. The manually outlining of extensor muscles volumes was reliable and only 8 slices of the calf were needed. No difference was seen between the two used mathematical calculations. (orig.)

Anatomical feasibility study of flexor hallucis longus transfer in treatment of Achilles tendon and posteromedial portal of ankle arthroscopy.

Science.gov (United States)

Mao, Haijiao; Wang, Linger; Dong, Wenwei; Liu, Zhenxin; Yin, Weigang; Xu, Dachuan; Wapner, Keith L

2018-04-16

The aim of this study was to evaluate the occurrence of anatomical variations of the musculotendinous junction of the flexor hallucis longus (FHL) muscle, the relationship between FHL tendon or muscle and the tibial neurovascular bundle at the level of the posterior ankle joint in human cadavers. Seventy embalmed feet from 20 male and 15 female cadavers, the cadavers' mean age was 65.4 (range from 14 to 82) years, were dissected and anatomically classified to observe FHL muscle morphology define the relationship between FHL tendon or muscle and the tibial neurovascular bundle. The distance between the musculotendinous junction and the relationship between FHL tendon or muscle and the tibial neurovascular bundle was determined. Three morphology types of FHL muscle were identified: a long lateral and shorter medial muscle belly, which was observed in 63 specimens (90%); equal length medial and lateral muscle bellies, this variant was only observed in five specimens (7.1%); one lateral and no medial muscle belly, which was observed in two specimens (2.9%). No statistically significant difference was observed according to gender or side (p > 0.05). Two patterns were identified and described between FHL tendon or muscle and the tibial neurovascular bundle. Pattern 1, the distance between the neurovascular bundle and FHL tendon was 3.46 mm (range 2.34-8.84, SD = 2.12) which was observed in 66 specimens (94.3%); Pattern 2, there was no distance which was observed in four specimens (5.7%). Knowing FHL muscle morphology, variations provide new important insights into secure planning and execution of a FHL transfer for Achilles tendon defect as well as for the interpretation of ultrasound and magnetic resonance images. With posterior arthroscopic for the treatment of various ankle pathologies, posteromedial portal may be introduced into the posterior aspect of the ankle without gross injury to the tibial neurovascular structures because of the gap between the

Ischemia Increases the Twitch Latent Period in the Soleus and Extensor Carpi Radialis Longus Muscles from Adult Rats.

Science.gov (United States)

Morales, Camilo; Fierro, Leonardo

2017-10-01

Complete ischemia and reperfusion effects on twitch force (∫(F·t)), twitch latent period (TLP), maximal rate of rise of twitch tension (δF/δt) max , and twitch maximum relaxation rate (TMRR) were assessed. We divided 36 adult rats into four groups; two control groups (n = 9), a group undergoing 1 hour of ischemia followed by 1 hour of reperfusion (n = 9), and one group exposed to 2 hours of ischemia followed by 1 hour of reperfusion (n = 9). We have induced twitch contractions every 10 minutes in the soleus and the extensor carpi radialis longus (ECRL). Twitch contractions were recorded and then analyzed for ∫(F·t), TLP, (δF/δt) max , and TMRR. During 1 hour and 40 minutes of ischemia, TLP increased to 179 ± 24% (p values.

Stretch-stimulated glucose transport in skeletal muscle is regulated by Rac1.

Science.gov (United States)

Sylow, Lykke; Møller, Lisbeth L V; Kleinert, Maximilian; Richter, Erik A; Jensen, Thomas E

2015-02-01

Rac1 regulates stretch-stimulated (i.e. mechanical stress) glucose transport in muscle. Actin depolymerization decreases stretch-induced glucose transport in skeletal muscle. Rac1 is a required part of the mechanical stress-component of the contraction-stimulus to glucose transport in skeletal muscle. An alternative to the canonical insulin signalling pathway for glucose transport is muscle contraction/exercise. Mechanical stress is an integrated part of the muscle contraction/relaxation cycle, and passive stretch stimulates muscle glucose transport. However, the signalling mechanism regulating stretch-stimulated glucose transport is not well understood. We recently reported that the actin cytoskeleton regulating GTPase, Rac1, was activated in mouse muscle in response to stretching. Rac1 is a regulator of contraction- and insulin-stimulated glucose transport, however, its role in stretch-stimulated glucose transport and signalling is unknown. We therefore investigated whether stretch-induced glucose transport in skeletal muscle required Rac1 and the actin cytoskeleton. We used muscle-specific inducible Rac1 knockout mice as well as pharmacological inhibitors of Rac1 and the actin cytoskeleton in isolated soleus and extensor digitorum longus muscles. In addition, the role of Rac1 in contraction-stimulated glucose transport during conditions without mechanical load on the muscles was evaluated in loosely hanging muscles and muscles in which cross-bridge formation was blocked by the myosin ATPase inhibitors BTS and Blebbistatin. Knockout as well as pharmacological inhibition of Rac1 reduced stretch-stimulated glucose transport by 30-50% in soleus and extensor digitorum longus muscle. The actin depolymerizing agent latrunculin B similarly decreased glucose transport in response to stretching by 40-50%. Rac1 inhibition reduced contraction-stimulated glucose transport by 30-40% in tension developing muscle but did not affect contraction-stimulated glucose transport in

Using a double-layered palmaris longus tendon for suspension of facial paralysis

DEFF Research Database (Denmark)

Toyserkani, Navid Mohamadpour; Bakholdt, Vivi; Sørensen, Jens Ahm

2015-01-01

follow-up of 49 months (range: 3-89 months). 93% noted an improvement of their facial appearance at follow-up. Seven out of 11 patients with preoperative problems with speech noted an improvement at follow-up. Eight out of 12 patients with preoperative problems with oral competence noted an improvement...

Foot posture influences the electromyographic activity of selected lower limb muscles during gait

Directory of Open Access Journals (Sweden)

Menz Hylton B

2009-11-01

Full Text Available Abstract Background Some studies have found that flat-arched foot posture is related to altered lower limb muscle function compared to normal- or high-arched feet. However, the results from these studies were based on highly selected populations such as those with rheumatoid arthritis. Therefore, the objective of this study was to compare lower limb muscle function of normal and flat-arched feet in people without pain or disease. Methods Sixty adults aged 18 to 47 years were recruited to this study. Of these, 30 had normal-arched feet (15 male and 15 female and 30 had flat-arched feet (15 male and 15 female. Foot posture was classified using two clinical measurements (the arch index and navicular height and four skeletal alignment measurements from weightbearing foot x-rays. Intramuscular fine-wire electrodes were inserted into tibialis posterior and peroneus longus under ultrasound guidance, and surface EMG activity was recorded from tibialis anterior and medial gastrocnemius while participants walked barefoot at their self-selected comfortable walking speed. Time of peak amplitude, peak and root mean square (RMS amplitude were assessed from stance phase EMG data. Independent samples t-tests were performed to assess for significant differences between the normal- and flat-arched foot posture groups. Results During contact phase, the flat-arched group exhibited increased activity of tibialis anterior (peak amplitude; 65 versus 46% of maximum voluntary isometric contraction and decreased activity of peroneus longus (peak amplitude; 24 versus 37% of maximum voluntary isometric contraction. During midstance/propulsion, the flat-arched group exhibited increased activity of tibialis posterior (peak amplitude; 86 versus 60% of maximum voluntary isometric contraction and decreased activity of peroneus longus (RMS amplitude; 25 versus 39% of maximum voluntary isometric contraction. Effect sizes for these significant findings ranged from 0.48 to 1

Isolated flexor pollicis longus nerve fascicle lesion – a rare differential diagnosis of thumb flexion deficiency

Directory of Open Access Journals (Sweden)

Glauser, Eva

2016-12-01

Full Text Available A rare differential diagnosis of thumb flexion deficiency is an isolated flexor pollicis longus (FPL nerve fascicle lesion. We present a 42-year-old otherwise healthy female patient who developed a weak thumb-to-index pinch and deficient right thumb flexion following the removal of osteosynthesis plates after a forearm fracture. Clinically,the flexor pollicis longus function was absent, yet index flexion and sensibility were unimpaired. Tendon rupture was excluded using a tenodesis test and the electro-physiological result of isolated interosseus nerve fascicle lesion was confirmed intraoperatively by inspection and electrostimulation. Tendon transfer using the extensor carpi radialis longus reconstruct strong thumb flexion during pinch. In summary, due to its specific location and anatomy, the FPL branch is more prone to isolated neuropathy, e.g. by injections or operations, than to other fascicles of the anterior interosseus nerve. When confronted with sudden and isolated thumb flexion deficiency, specialists should be aware of this rare phenomenon.

Ca2+ uptake and cellular integrity in rat EDL muscle exposed to electrostimulation, electroporation, or A23187

DEFF Research Database (Denmark)

Gissel, Hanne; Clausen, Torben

2003-01-01

We tested the hypothesis that increased Ca2+ uptake in rat extensor digitorum longus (EDL) muscle elicits cell membrane damage as assessed from release of the intracellular enzyme lactate dehydrogenase (LDH). This was done by using 1) electrostimulation, 2) electroporation, and 3) the Ca2+ ionoph...

Covering the Dorsal Finger Defect with Reverse Cross Finger Flap

Directory of Open Access Journals (Sweden)

Kaan Gurbuz

2014-12-01

Full Text Available Reconstruction of finger extensor zone defects with or without tendon gaps still remains a challenge for surgeons. Although surgical treatments may differ, and range from the use of local, regional, to free flaps, the outcomes for all cases are not satisfactory. In this case report, we present a case of a 3rd finger extensor side crush injury including a defect of Dd (Digit Dorsal 1, Dd2 and Dd3 defects of extensor zones with tendon gap. Tendon gap was reconstructed using m. palmaris longus tendon graft and the defect was covered with reversed cross-finger flap (random pattern with good cosmetic and excellent functional results.

Arthroscopic-Assisted Triangular Fibrocartilage Complex Reconstruction.

Science.gov (United States)

Chu-Kay Mak, Michael; Ho, Pak-Cheong

2017-11-01

Injury of the triangular fibrocartilage complex (TFCC) is a common cause of ulnar-sided wrist pain. Volar and dorsal radioulnar ligaments and their foveal insertion are the most important stabilizing components of the TFCC. In irreparable tears, anatomic reconstruction of the TFCC aims to restore normal biomechanics and stability of the distal radioulnar joint. We proposed a novel arthroscopic-assisted technique using a palmaris longus tendon graft. Arthroscopic-assisted TFCC reconstruction is a safe and effective approach with outcomes comparable to conventional open reconstruction and may result in a better range of motion from minimizing soft tissue dissection and subsequent scarring. Copyright © 2017 Elsevier Inc. All rights reserved.

Muscle sarcomere lesions and thrombosis after spaceflight and suspension unloading

Energy Technology Data Exchange (ETDEWEB)

Riley, D.A.; Ellis, S.; Giometti, C.S.; Hoh, J.F.Y.; Ilyina-Kakueva, E.I.; Oganov, V.S.; Slocum, G.R.; Bain, J.L.W.; Sedlak, F.R. (Argonne National Lab., IL (United States))

1992-08-01

Extended exposure of humans to spaceflight produces a progressive loss of skeletal muscle strength. This process must be understood to design effective countermeasures. The present investigation examined hindlimb muscles from flight rats killed as close to landing as possible. Spaceflight and tail suspension-hindlimb unloading (unloaded) produced significant decreases in fiber cross-sectional areas of the adductor longus (AL), a slow-twitch antigravity muscle. However, the mean wet weight of the flight AL muscles was near normal, whereas that of the suspension unloaded AL muscles was significantly reduced. Interstitial edema within the flight AL, but not in the unloaded AL, appeared to account for this apparent disagreement.In both conditions, the slow-twitch oxidative fibers atrophied more than the fast-twitch oxidative-glycolytic fibers. Microcirculation was also compromised by spaceflight, such that there was increased formation of thrombi in the postcapillary venules and capillaries.

Impact of high intensity exercise on muscle morphology in EAE rats

DEFF Research Database (Denmark)

Wens, I; Dalgas, U; Verboven, K

2015-01-01

paralysis (experiment 2, n=40), isokinetic foot extensor strength, cross sectional area (CSA) of tibialis anterior (TA), extensor digitorum longus (EDL) and soleus (SOL) and brain-derived neurotrophic factor (BDNF) levels were assessed. EAE reduced muscle fiber CSA of TA, EDL and SOL. In general, exercise...... was not able to affect CSA, whereas it delayed hindquarter paralysis peak. CON muscle work peaked and declined, while it remained stable in EAE. BDNF-responses were not affected by EAE or exercise. In conclusion, EAE affected CSA-properties of TA, EDL and SOL, which could, partly, explain the absence of peak...

When phosphorylated at Thr148, the β2-subunit of AMP-activated kinase does not associate with glycogen in skeletal muscle.

Science.gov (United States)

Xu, Hongyang; Frankenberg, Noni T; Lamb, Graham D; Gooley, Paul R; Stapleton, David I; Murphy, Robyn M

2016-07-01

The 5'-AMP-activated protein kinase (AMPK), a heterotrimeric complex that functions as an intracellular fuel sensor that affects metabolism, is activated in skeletal muscle in response to exercise and utilization of stored energy. The diffusibility properties of α- and β-AMPK were examined in isolated skeletal muscle fiber segments dissected from rat fast-twitch extensor digitorum longus and oxidative soleus muscles from which the surface membranes were removed by mechanical dissection. After the muscle segments were washed for 1 and 10 min, ∼60% and 75%, respectively, of the total AMPK pools were found in the diffusible fraction. After in vitro stimulation of the muscle, which resulted in an ∼80% decline in maximal force, 20% of the diffusible pool became bound in the fiber. This bound pool was not associated with glycogen, as determined by addition of a wash step containing amylase. Stimulation of extensor digitorum longus muscles resulted in 28% glycogen utilization and a 40% increase in phosphorylation of the downstream AMPK target acetyl carboxylase-CoA. This, however, had no effect on the proportion of total β2-AMPK that was phosphorylated in whole muscle homogenates measured by immunoprecipitation. These findings suggest that, in rat skeletal muscle, β2-AMPK is not associated with glycogen and that activation of AMPK by muscle contraction does not dephosphorylate β2-AMPK. These findings question the physiological relevance of the carbohydrate-binding function of β2-AMPK in skeletal muscle. Copyright © 2016 the American Physiological Society.

Modulation of the Fibularis Longus Hoffmann Reflex and Postural Instability Associated With Chronic Ankle Instability

Science.gov (United States)

Kim, Kyung-Min; Hart, Joseph M.; Saliba, Susan A.; Hertel, Jay

2016-01-01

Context: Individuals with chronic ankle instability (CAI) present with decreased modulation of the Hoffmann reflex (H-reflex) from a simple to a more challenging task. The neural alteration is associated with impaired postural control, but the relationship has not been investigated in individuals with CAI. Objective: To determine differences in H-reflex modulation and postural control between individuals with or without CAI and to identify if they are correlated in individuals with CAI. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: A total of 15 volunteers with CAI (9 males, 6 females; age = 22.6 ± 5.8 years, height = 174.7 ± 8.1 cm, mass = 74.9 ± 12.8 kg) and 15 healthy sex-matched volunteers serving as controls (9 males, 6 females; age = 23.8 ± 5.8 years, height = 171.9 ± 9.9 cm, mass = 68.9 ± 15.5 kg) participated. Intervention(s): Maximum H-reflex (Hmax) and motor wave (Mmax) from the soleus and fibularis longus were recorded while participants lay prone and then stood in unipedal stance. We assessed postural tasks of unipedal stance with participants' eyes closed for 10 seconds using a forceplate. Main Outcome Measure(s): We normalized Hmax to Mmax to obtain Hmax : Mmax ratios for the 2 positions. For each muscle, H-reflex modulation was quantified using the percentage change scores in Hmax : Mmax ratios calculated from prone position to unipedal stance. Center-of-pressure data were used to compute 4 time-to-boundary variables. Separate independent-samples t tests were performed to determine group differences. Pearson product moment correlation coefficients were calculated between the modulation and balance measures in the CAI group. Results: The CAI group presented less H-reflex modulation in the soleus (t26 = −3.77, P = .001) and fibularis longus (t25 = −2.59, P = .02). The mean of the time-to-boundary minima in the anteroposterior direction was lower in the CAI group (t28 = −2.06, P = .048

Different β-adrenergic receptor density in different rat skeletal muscle fibre types

International Nuclear Information System (INIS)

Jensen, J.; Dahl, H.A.; Broers, O.

1995-01-01

The effects of adrenaline on skeletal muscle differ between fibre types. The aim of the present study was to investigate the β-adrenoceptor density, affinity and subtype in rat skeletal muscles with different fibre type composition. β-Adrenoceptors were determined in cryostat sections to avoid methodological problems with variable recovery, using the non-selective βadrenoceptor ligand [ 3 H]CGP-12177 and β 1 - and β 2 -selective cold ligands CGP 20712A and ICI 118,551. In the presence of protease inhibitors [ 3 H]CGP-12177 binding was stable, saturable, reversible, and displaceable. Scatchard analysis of binding saturation data was compatible with a single class of specific binding sites. Binding site density (B max ) was higher (P -1 ) than in adult extensor digitorum longus (4.74±0.39 fmol x mg protein -1 ), whereas the dissociation constants (K d ), 0.37±0.05 and 0.31±0.04 nM for soleus and extensor digitorum longus, respectively, were not significantly different. For young rats (5-6 weeks), B max was 11.21±0.33 and 5.45±0.11 fmol x mg protein -1 (P d was 0.27±0.02 and 0.24±0.04 nM for soleus and epitrochlearis, respectively. These results correspond to a receptor density of 2 and 1 pmol x g w.wt. -1 in muscles containing mainly type I and type II fibres, respectively. Displacement studies with CGP 20712A and ICI 118,551 were compatible with mainly β 2 -adrenoceptors, but 7-10% β 1 -adrenoceptors were present in both types of muscle. In conclusion, the receptor density is twice as high in muscles containing mainly type I muscle fibres compared to muscles containing mainly type II fibres, and this may explain some of the different effects of adrenaline between the two muscle fibre types. (au)

Brain-derived neurotrophic factor is produced by skeletal muscle cells in response to contraction and enhances fat oxidation via activation of AMP-activated protein kinase

DEFF Research Database (Denmark)

Matthews, V B; Åström, Maj-Brit; Chan, M H S

2009-01-01

C12 skeletal muscle cells were electrically stimulated to mimic contraction. L6 myotubes and isolated rat extensor digitorum longus muscles were treated with BDNF and phosphorylation of the proteins AMP-activated protein kinase (AMPK) (Thr(172)) and acetyl coenzyme A carboxylase beta (ACCbeta) (Ser...... kinase (p44/42 Thr(202)/Tyr(204)) phosphorylation in these muscles. In addition, phosphorylation of ACCbeta was markedly elevated in the Bdnf electroporated muscles. CONCLUSIONS/INTERPRETATION: These data identify BDNF as a contraction-inducible protein in skeletal muscle that is capable of enhancing...

beta-adrenergic effects on carbohydrate metabolism in the unweighted rat soleus muscle

Science.gov (United States)

Kirby, Christopher R.; Tischler, Marc E.

1990-01-01

The effect of unweighting on the response of the soleus-muscle carbohydrate metabolism to a beta-adrenergic agonist (isoproterenol) was investigated in rats that were subjected to three days of tail-cast suspension. It was found that isoproterenol promoted glycogen degradation in soleus from suspended rats to a higher degree than in weighted soleus from control rats, and had no effect in unweighted digitorum longus. However, isoproterenol did not have a greater inhibitory effect on the net uptake of tritium-labeled 2-deoxy-glucose by the unweighted soleus and that isoproterenol inhibited hexose phosphorylation less in the unweighted than in the control muscle.

An anomalous accessory extensor proprius indicis muscle: A case report

Directory of Open Access Journals (Sweden)

Mustafa Kurklu

2013-12-01

Full Text Available Variations related to tendon insertion and musculotendinous junction of the extensor proprius indicis muscle are commonly encountered. An anomalous extensor indicis proprius muscle (EIP tendon was detected in a fifty-year-old female cadaver during routine dissection of the right upper extremity. The body of tendon was initiated from the posterior ulna as a one muscle body, then continued as two separate muscle bodies and tendons and finally they were separated into two slips after passing the fourth dorsal compartment. As a radial part, it was divided into two slips at the level of the first metacarpophalangeal joint, and conjugated with the extensor pollicis longus (EPL muscle. Then, as an ulnar part, it was terminated at the radial side of the lateral band of the second metacarpophalangeal joint. Familiarity with the normal anatomy and variations of the tendons may help to prevent confusion and mistakes during tendon repairs, and tendon transfers. [Hand Microsurg 2013; 2(3.000: 122-124

Chronic exercise increases insulin binding in muscles but not liver

International Nuclear Information System (INIS)

Bonen, A.; Clune, P.A.; Tan, M.H.

1986-01-01

It has been postulated that the improved glucose tolerance provoked by chronic exercise is primarily attributable to increased insulin binding in skeletal muscle. Therefore, the authors investigated the effects of progressively increased training (6 wk) on insulin binding by five hindlimb skeletal muscles and in liver. In the trained animals serum insulin levels at rest were lower either in a fed or fasted state and after an oral glucose tolerance test. Twenty-four hours after the last exercise bout sections of the liver, soleus (S), plantaris (P), extensor digitorum longus (EDL), and red (RG) and white gastrocnemius (WG) muscles were pooled from four to six rats. Insulin binding to plasma membranes increased in S, P, and EDL but not in WG or in liver. There were insulin binding differences among muscles. Comparison of rank orders of insulin binding data with published glucose transport data for the same muscles revealed that these parameters do not correspond well. In conclusion, insulin binding to muscle is shown to be heterogeneous and training can increase insulin binding to selected muscles but not liver

Acute Retropharyngeal Calcific Tendinitis in an Unusual Location: a Case Report in a Patient with Rheumatoid Arthritis and Atlantoaxial Subluxation

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Hun; Joo, Kyung Bin; Lee, Kyu Hoon; Uhm, Wan Sik [Hanyang University Hospital, Seoul (Korea, Republic of)

2011-08-15

Retropharyngeal calcific tendinitis is defined as inflammation of the longus colli muscle and is caused by the deposition of calcium hydroxyapatite crystals, which usually involves the superior oblique fibers of the longus colli muscle from C1-3. Diagnosis is usually made by detecting amorphous calcification and prevertebral soft tissue swelling on radiograph, CT or MRI. In this report, we introduce a case of this disease which was misdiagnosed as a retropharyngeal tuberculous abscess, or a muscle strain of the ongus colli muscle. No calcifications were visible along the vertical fibers of the longus colli muscle. The lesion was located anterior to the C4-5 disc, in a rheumatoid arthritis patient with atlantoaxial subluxation. Calcific tendinitis of the longus colli muscle at this location in a rheumatoid arthritis patient has not been reported in the English literature.

Two weeks of metformin treatment induces AMPK dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

DEFF Research Database (Denmark)

Kristensen, Jonas Møller; Treebak, Jonas Thue; Schjerling, Peter

2014-01-01

signaling. Methods: Oral doses of metformin or saline treatment were given muscle-specific kinase α2 dead AMPK mice (KD) and wild type (WT) littermates either once or chronically for 2 weeks. Soleus and Extensor Digitorum Longus (EDL) muscles were used for measurements of glucose transport and Western blot......Background: Metformin-induced activation of AMPK has been associated with enhanced glucose uptake in skeletal muscle but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent upon AMPK...... analyzes. Results: Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (45%, P...

Cuboid oedema due to peroneus longus tendinopathy: a report of four cases

International Nuclear Information System (INIS)

O'Donnell, Paul; Saifuddin, Asif

2005-01-01

To highlight focal bone abnormality in the cuboid due to tendinopathy of the adjacent peroneus longus. A retrospective review was carried out of the relevant clinical and imaging features. Two male and two female patients were studied, mean age 51.5 years (range 32 - 67 years), referred with foot pain and imaging showing an abnormal cuboid thought to represent either tumour or infection. A long history of foot pain was usual with a maximum of 8 years. Radiographs were normal in two cases and showed erosion in two, one of which exhibited periosteal new bone formation affecting the cuboid. Bone scintigraphy was undertaken in two patients, both of whom showed increased uptake of isotope. MRI, performed in all patients, showed oedema in the cuboid adjacent to the peroneus longus tendon. The tendon and/or paratendinous tissues were abnormal in all cases, but no tendon discontinuity was identified. One patient possessed an os peroneum. Unequivocal evidence of bone erosion was seen using MRI in three patients, but with greater clarity in two cases using CT. Additional findings of tenosynovitis of tibialis posterior, oedema in the adjacent medial malleolus and synovitis of multiple joints in the foot were seen in one patient. Imaging diagnosis was made in all cases avoiding bone biopsy, but surgical exploration of the peroneal tendons was performed in two cases and biopsy of ankle synovium in one. Oedema with erosion of the cuboid bone, simulating a bone lesion (cuboid ''pseudotumour''), may be caused by adjacent tendinopathy of peroneus longus. It is vital to be aware of this entity to avoid unnecessary biopsy of the cuboid. (orig.)

Cuboid oedema due to peroneus longus tendinopathy: a report of four cases

Energy Technology Data Exchange (ETDEWEB)

O' Donnell, Paul; Saifuddin, Asif [Royal National Orthopaedic Hospital NHS Trust, Department of Radiology, Stanmore, Middlesex (United Kingdom)

2005-07-01

To highlight focal bone abnormality in the cuboid due to tendinopathy of the adjacent peroneus longus. A retrospective review was carried out of the relevant clinical and imaging features. Two male and two female patients were studied, mean age 51.5 years (range 32 - 67 years), referred with foot pain and imaging showing an abnormal cuboid thought to represent either tumour or infection. A long history of foot pain was usual with a maximum of 8 years. Radiographs were normal in two cases and showed erosion in two, one of which exhibited periosteal new bone formation affecting the cuboid. Bone scintigraphy was undertaken in two patients, both of whom showed increased uptake of isotope. MRI, performed in all patients, showed oedema in the cuboid adjacent to the peroneus longus tendon. The tendon and/or paratendinous tissues were abnormal in all cases, but no tendon discontinuity was identified. One patient possessed an os peroneum. Unequivocal evidence of bone erosion was seen using MRI in three patients, but with greater clarity in two cases using CT. Additional findings of tenosynovitis of tibialis posterior, oedema in the adjacent medial malleolus and synovitis of multiple joints in the foot were seen in one patient. Imaging diagnosis was made in all cases avoiding bone biopsy, but surgical exploration of the peroneal tendons was performed in two cases and biopsy of ankle synovium in one. Oedema with erosion of the cuboid bone, simulating a bone lesion (cuboid ''pseudotumour''), may be caused by adjacent tendinopathy of peroneus longus. It is vital to be aware of this entity to avoid unnecessary biopsy of the cuboid. (orig.)

Muscular activity and torque of the foot dorsiflexor muscles during decremental isometric test: A cross-sectional study.

Science.gov (United States)

Ruiz-Muñoz, Maria; González-Sánchez, Manuel; Martín-Martín, Jaime; Cuesta-Vargas, Antonio I

2017-06-01

To analyse the torque variation level that could be explained by the muscle activation (EMG) amplitude of the three major foot dorsiflexor muscles (tibialis anterior (TA), extensor digitorum longus (EDL), extensor hallucis longus (EHL)) during isometric foot dorsiflexion at different intensities. In a cross-sectional study, forty-one subjects performed foot dorsiflexion at 100%, 75%, 50% and 25% of maximal voluntary contractions (MVC) with the hip and knee flexed 90° and the ankle in neutral position (90° between leg and foot). Three foot dorsiflexions were performed for each intensity. Outcome variables were: maximum (100% MVC) and relative torque (75%, 50%, 25% MVC), maximum and relative EMG amplitude. A linear regression analysis was calculated for each intensity of the isometric foot dorsiflexion. The degree of torque variation (dependent variable) from the independent variables explain (EMG amplitude of the three major foot dorsiflexor muscles) the increases when the foot dorsiflexion intensity is increased, with values of R 2 that range from 0.194 (during 25% MVC) to 0.753 (during 100% MVC). The reliability of the outcome variables was excellent. The EMG amplitude of the three main foot dorsiflexors exhibited more variance in the dependent variable (torque) when foot dorsiflexion intensity increases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Matching of sarcoplasmic reticulum and contractile properties in rat fast- and slow-twitch muscle fibres.

Science.gov (United States)

Trinh, Huong H; Lamb, Graham D

2006-07-01

1. The twitch characteristics (fast-twitch or slow-twitch) of skeletal muscle fibres are determined not only by the contractile apparatus properties of the fibre, but also by the time-course of Ca2+ release and re-uptake by the sarcoplasmic reticulum (SR). The present study examined, in individual fibres from non-transforming muscle of the rat, whether particular SR properties are matched to the contractile apparatus properties of the fibre, in particular in the case of fibres with fast-twitch contractile apparatus located in a slow-twitch muscle, namely the soleus. 2. Force was recorded in single, mechanically skinned fibres from extensor digitorum longus (EDL), gastrocnemius, peroneus longus and soleus muscles. Using repeated cycles in which the SR was emptied of all releasable Ca2+ and then reloaded, it was possible to determine the relative amount of Ca2+ present in the SR endogenously, the maximum SR capacity and the rate of Ca2+ loading. The sensitivity of the contractile apparatus to Ca2+ and Sr2+ was used to classify the fibres as fast-twitch (FT), slow-twitch (ST) or mixed (fibres examined) and thereby identify the likely troponin C and myosin heavy chain types present. 3. There was no significant difference in SR properties between the groups of FT fibres obtained from the four different muscles, including soleus. Despite some overlap in the SR properties of individual fibres between the FT and ST groups, the properties of the FT fibres in all four muscles studied were significantly different from those of the ST and mixed fibres. 4. In general, in FT fibres the SR had a larger capacity and the endogenous Ca2+ content was a relatively lower percentage of maximum compared with ST fibres. Importantly, in terms of their SR properties, FT fibres from soleus muscle more closely resembled FT fibres from other muscles than they did ST fibres from soleus muscle.

EMG of the hip adductor muscles in six clinical examination tests.

Science.gov (United States)

Lovell, Gregory A; Blanch, Peter D; Barnes, Christopher J

2012-08-01

To assess activation of muscles of hip adduction using EMG and force analysis during standard clinical tests, and compare athletes with and without a prior history of groin pain. Controlled laboratory study. 21 male athletes from an elite junior soccer program. Bilateral surface EMG recordings of the adductor magnus, adductor longus, gracilis and pectineus as well as a unilateral fine-wire EMG of the pectineus were made during isometric holds in six clinical examination tests. A load cell was used to measure force data. Test type was a significant factor in the EMG output for all four muscles (all muscles p stronger than Hips 45, Hips 90 and Side lay. BMI (body mass index) was a significant factor (p Muscle EMG varied significantly with clinical test position. Athletes with previous groin injury had a significant fall in some EMG outputs. Copyright © 2011 Elsevier Ltd. All rights reserved.

Morphological changes in the cervical muscles of women with chronic whiplash can be modified with exercise-A pilot study.

Science.gov (United States)

O'leary, Shaun; Jull, Gwendolen; Van Wyk, Luke; Pedler, Ashley; Elliott, James

2015-11-01

In this preliminary study we determined whether MRI markers of cervical muscle degeneration [elevated muscle fatty infiltration (MFI), cross-sectional area (CSA), and reduced relative muscle CSA (rmCSA)] could be modified with exercise in patients with chronic whiplash. Five women with chronic whiplash undertook 10 weeks of neck exercise. MRI measures of the cervical multifidus (posterior) and longus capitus/colli (anterior) muscles, neck muscle strength, and self-reported neck disability were recorded at baseline and at completion of the exercise program. Overall significant increases in CSA and rmCSA were observed for both muscles, but significant reductions in MFI were only evident in the cervical multifidus muscle. These changes coincided with increased muscle strength and reduced neck disability. MRI markers of muscle morphology in individuals with chronic whiplash appear to be modifiable with exercise. © 2015 Wiley Periodicals, Inc.

Downstream mechanisms of nitric oxide-mediated skeletal muscle glucose uptake during contraction.

Science.gov (United States)

Merry, Troy L; Lynch, Gordon S; McConell, Glenn K

2010-12-01

There is evidence that nitric oxide (NO) is required for the normal increases in skeletal muscle glucose uptake during contraction, but the mechanisms involved have not been elucidated. We examined whether NO regulates glucose uptake during skeletal muscle contractions via cGMP-dependent or cGMP-independent pathways. Isolated extensor digitorum longus (EDL) muscles from mice were stimulated to contract ex vivo, and potential NO signaling pathways were blocked by the addition of inhibitors to the incubation medium. Contraction increased (P contraction by ∼50% (P contraction; however, DTT attenuated (P contraction-stimulated glucose uptake (by 70%). NOS inhibition and antioxidant treatment reduced contraction-stimulated increases in protein S-glutathionylation and tyrosine nitration (P skeletal muscle glucose uptake during ex vivo contractions via a cGMP/PKG-, AMPK-, and p38 MAPK-independent pathway. In addition, it appears that NO and ROS may regulate skeletal muscle glucose uptake during contraction through a similar pathway.

Heat production during contraction in skeletal muscle of hypothyroid mice

International Nuclear Information System (INIS)

Leijendekker, W.J.; van Hardeveld, C.; Elzinga, G.

1987-01-01

The effect of hypothyroidism on tension-independent and -dependent heat produced during a twitch and a tetanic contraction of extensor digitorum longus (EDL) and soleus muscle of mice was examined. The amount of heat produced during a twitch and the rate of heat development during a tetanus of EDL and soleus were measured at and above optimal length. The effect of hypothyroidism on force production was 2+ cycling, these findings suggest that ATP splitting due to the Ca 2+ cycling is reduced in hypothyroid mice. This conclusion was strengthened by the observation that the oxalate-supported 45 Ca 2+ -uptake activity and 45 Ca 2+ -loading capacity of muscle homogenates from hypothyroid mice were reduced, respectively, to 51 and to 65% in soleus and to 63 and 73% in EDL muscle as compared with euthyroid mice. The tension-dependent rate of heat development during a tetanus was also decreased in soleus muscle of hypothyroid mice. This suggests a lower rate of ATP hydrolysis related to cross-bridge cycling in this muscle due to the hypothyroid state

Anatomic relationship of the proximal nail matrix to the extensor hallucis longus tendon insertion.

Science.gov (United States)

Palomo López, P; Becerro de Bengoa Vallejo, R; López López, D; Prados Frutos, J C; Alfonso Murillo González, J; Losa Iglesias, M E

2015-10-01

The purpose of this study was to delineate the relationship of the terminal extensor hallucis longus tendon insertion to the proximal limit of the nail matrix of the great toe. Fifty fresh-frozen human cadaver great toes with no evidence of trauma (average age, 62.5 years; 29 males and 21 females) were used for this study. Under 25X magnification, the proximal limit of the nail matrix and the terminal bony insertion of the extensor hallucis longus tendons were identified. The distance from the terminal tendon insertion to the nail matrix was ascertained using precision calipers, an optical microscope, and autocad(®) software for windows. Twenty-five great toes were placed in a neutral formalin solution and further analysed by histological longitudinal-sections. The specimens were stained with haematoxylin and eosin and examined microscopically to determine the presence of the extensor hallucis longus tendon along the dorsal aspect of the distal phalanx of each great toe. The main result we found in great toes was that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx in all, 100%, specimens. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of the distal phalanx as is the case for fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. We have found that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of distal phalanx as is the case in fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. Our anatomic study demonstrates that the proximal limit of the matrix and nail bed of the human great toe are dorsal and

Mitochondrial oxidative enzyme activity in individual fibre types in hypo- and hyperthyroid rat skeletal muscles.

Science.gov (United States)

Johnson, M A; Turnbull, D M

1984-04-01

Quantitative cytochemical and biochemical techniques have been used in combination to study the response of mitochondrial oxidative enzymes in individual muscle fibre types to hypo- and hyperthyroidism. Hypothyroidism resulted in decreased activity of succinate dehydrogenase (SDH), L-glycerol-3-phosphate dehydrogenase (L-GPDH), and D-3-hydroxybutyrate dehydrogenase (D-HBDH) in all fibre types of both slow-twitch soleus and fast-twitch extensor digitorum longus (e.d.l.) muscles. In hyperthyroidism, only L-GPDH activity increased in e.d.l. but more marked increases were seen in soleus muscles, which also showed increased SDH activity. In addition to these alterations in the enzyme activity in individual fibre types the metabolic profile of the muscle is further modified by the hormone-induced interconversion of slow- to fast-twitch fibres and vice versa.

Glycolysis in contracting rat skeletal muscle is controlled by factors related to energy state

DEFF Research Database (Denmark)

Ørtenblad, Niels; Macdonald, Will A; Sahlin, Kent

2009-01-01

The control of glycolysis in contracting muscle is not fully understood. The aim of the present study was to examine whether activation of glycolysis is mediated by factors related to the energy state or by a direct effect of Ca2+ on the regulating enzymes. Extensor digitorum longus muscles from...... and 58% of those in Con respectively. Glycolytic rate in BTS was only 51% of that in Con but the relative contribution of ATP derived from PCr (phosphocreatine) and glycolysis and the relation between muscle contents of PCr and Lac (lactate) were not different. Prolonged cyanide incubation of quiescent...... contribution of energy delivered from PCr and glycolysis during both conditions suggests that the glycolytic rate is controlled by factors related to energy state....

Both short intense and prolonged moderate in vitro stimulation reduce the mRNA expression of calcium-regulatory proteins in rat skeletal muscle

DEFF Research Database (Denmark)

Mänttäri, Satu; Ørtenblad, N; Madsen, Klavs

2013-01-01

RNA expression of components involved in Ca(2+) regulation in oxidative and glycolytic skeletal muscle. The mRNA level of Ca(2+)-ATPase (SERCA1, 2), calsequestrin (CASQ1, 2), ryanodine receptor (RyR1), and dihydropyridine receptor (Cacna1) was assessed in rat extensor digitorum longus (EDL) and soleus (SOL...

Flexor pollicis longus tenosynovitis in patients with carpal tunnel syndrome.

Science.gov (United States)

Manfield, Laura; Thomas, Mark; Lee, Se Won

2014-06-01

Carpal tunnel syndrome is typically diagnosed from history and physical examination then confirmed with electrodiagnosis. Electrodiagnosis provides only limited anatomic information and evaluation of space-occupying lesions. The authors present two cases in which demonstrated flexor pollicis longus tenosynovitis coexistent with carpal tunnel syndrome was diagnosed with ultrasonography. Ultrasonography is an effective modality that enhances the investigation of diseases in the soft tissues of the wrist and the hand. It can be useful in directing specific treatment by increasing diagnostic accuracy.

Impact of high intensity exercise on muscle morphology in EAE rats

DEFF Research Database (Denmark)

Wens, I; Dalgas, U; Verboven, K

2015-01-01

paralysis (experiment 2, n=40), isokinetic foot extensor strength, cross sectional area (CSA) of tibialis anterior (TA), extensor digitorum longus (EDL) and soleus (SOL) and brain-derived neurotrophic factor (BDNF) levels were assessed. EAE reduced muscle fiber CSA of TA, EDL and SOL. In general, exercise......The impact of high-intensity exercise on disease progression and muscle contractile properties in experimental autoimmune encephalomyelitis (EAE) remains unclear. Control (CON) and EAE rats were divided into sedentary and exercise groups. Before onset (experiment 1, n=40) and after hindquarter...... was not able to affect CSA, whereas it delayed hindquarter paralysis peak. CON muscle work peaked and declined, while it remained stable in EAE. BDNF-responses were not affected by EAE or exercise. In conclusion, EAE affected CSA-properties of TA, EDL and SOL, which could, partly, explain the absence of peak...

Rac1 Is a Novel Regulator of Contraction-Stimulated Glucose Uptake in Skeletal Muscle

Science.gov (United States)

Sylow, Lykke; Jensen, Thomas E.; Kleinert, Maximilian; Mouatt, Joshua R.; Maarbjerg, Stine J.; Jeppesen, Jacob; Prats, Clara; Chiu, Tim T.; Boguslavsky, Shlomit; Klip, Amira; Schjerling, Peter; Richter, Erik A.

2013-01-01

In skeletal muscle, the actin cytoskeleton-regulating GTPase, Rac1, is necessary for insulin-dependent GLUT4 translocation. Muscle contraction increases glucose transport and represents an alternative signaling pathway to insulin. Whether Rac1 is activated by muscle contraction and regulates contraction-induced glucose uptake is unknown. Therefore, we studied the effects of in vivo exercise and ex vivo muscle contractions on Rac1 signaling and its regulatory role in glucose uptake in mice and humans. Muscle Rac1-GTP binding was increased after exercise in mice (∼60–100%) and humans (∼40%), and this activation was AMP-activated protein kinase independent. Rac1 inhibition reduced contraction-stimulated glucose uptake in mouse muscle by 55% in soleus and by 20–58% in extensor digitorum longus (EDL; P Rac1 knockout mice. Furthermore, depolymerization of the actin cytoskeleton decreased contraction-stimulated glucose uptake by 100% and 62% (P Rac1 is activated during muscle contraction in murine and human skeletal muscle and suggest that Rac1 and possibly the actin cytoskeleton are novel regulators of contraction-stimulated glucose uptake. PMID:23274900

Comparative Statistical Mechanics of Muscle and Non-Muscle Contractile Systems: Stationary States of Near-Equilibrium Systems in A Linear Regime

Directory of Open Access Journals (Sweden)

Yves Lecarpentier

2017-10-01

Full Text Available A. Huxley’s equations were used to determine the mechanical properties of muscle myosin II (MII at the molecular level, as well as the probability of the occurrence of the different stages in the actin–myosin cycle. It was then possible to use the formalism of statistical mechanics with the grand canonical ensemble to calculate numerous thermodynamic parameters such as entropy, internal energy, affinity, thermodynamic flow, thermodynamic force, and entropy production rate. This allows us to compare the thermodynamic parameters of a non-muscle contractile system, such as the normal human placenta, with those of different striated skeletal muscles (soleus and extensor digitalis longus as well as the heart muscle and smooth muscles (trachea and uterus in the rat. In the human placental tissues, it was observed that the kinetics of the actin–myosin crossbridges were considerably slow compared with those of smooth and striated muscular systems. The entropy production rate was also particularly low in the human placental tissues, as compared with that observed in smooth and striated muscular systems. This is partly due to the low thermodynamic flow found in the human placental tissues. However, the unitary force of non-muscle myosin (NMII generated by each crossbridge cycle in the myofibroblasts of the human placental tissues was similar in magnitude to that of MII in the myocytes of both smooth and striated muscle cells. Statistical mechanics represents a powerful tool for studying the thermodynamics of all contractile muscle and non-muscle systems.

Experiment K-6-09. Morphological and biochemical investigation of microgravity-induced nerve and muscle breakdown. Part 1: Investigation of nerve and muscle breakdown during spaceflight; Part 2: Biochemical analysis of EDL and PLT muscles

Science.gov (United States)

Riley, D. A.; Ellis, S.; Bain, J.; Sedlak, F.; Slocum, G.; Oganov, V.

1990-01-01

The present findings on rat hindlimb muscles suggest that skeletal muscle weakness induced by prolonged spaceflight can result from a combination of muscle fiber atrophy, muscle fiber segmental necrosis, degeneration of motor nerve terminals and destruction of microcirculatory vessels. Damage was confined to the red adductor longus (AL) and soleus muscles. The midbelly region of the AL muscle had more segmental necrosis and edema than the ends. Macrophages and neutrophils were the major mononucleated cells infiltrating and phagocytosing the cellular debris. Toluidine blue-positive mast cells were significantly decreased in Flight AL muscles compared to controls; this indicated that degranulation of mast cells contributed to tissue edema. Increased ubiquitination of disrupted myofibrils may have promoted myofilament degradation. Overall, mitochondria content and SDH activity were normal, except for a decrease in the subsarcolemmal region. The myofibrillar ATPase activity shifted toward the fast type in the Flight AL muscles. Some of the pathological changes may have occurred or been exacerbated during the 2 day postflight period of readaptation to terrestrial gravity. While simple atrophy should be reversible by exercise, restoration of pathological changes depends upon complex processes of regeneration by stem cells. Initial signs of muscle and nerve fiber regeneration were detected. Even though regeneration proceeds on Earth, the space environment may inhibit repair and cause progressive irreversible deterioration during long term missions. Muscles obtained from Flight rats sacrificed immediately (within a few hours) after landing are needed to distinguish inflight changes from postflight readaptation.

L-carnitine pretreatment protects slow-twitch skeletal muscles in a rat model of ischemia-reperfusion injury.

Science.gov (United States)

Demirel, Mert; Kaya, Burak; Cerkez, Cem; Ertunc, Mert; Sara, Yildirim

2013-10-01

Ischemia-reperfusion (I/R) injury negatively affects the outcome of surgical interventions for amputated or severely traumatized extremities. This study aimed to evaluate the protective role of l-carnitine on the contractile properties of fast-twitch (extensor digitorum longus [EDL]) and slow-twitch (soleus [SOL]) skeletal muscles following I/R-induced injury in a rat model. Rats were divided into 4 groups (1) saline pretreatment, (2) l-carnitine pretreatment, (3) saline pretreatment and I/R, and (4) l-carnitine pretreatment and I/R. Twitch and tetanic contractions in the EDL and SOL muscles in each group were recorded. Additionally, a fatigue protocol was performed in these muscles. Twitch and tetanic contraction amplitudes were lower in the EDL and SOL muscles in which I/R was induced (P contraction amplitude in the SOL muscles following I/R (P muscles. l-Carnitine pretreatment did not alter the fatigue response in any of the muscles.

Gene Expression Profiling in Slow-Type Calf Soleus Muscle of 30 Days Space-Flown Mice.

Directory of Open Access Journals (Sweden)

Guido Gambara

Full Text Available Microgravity exposure as well as chronic disuse are two main causes of skeletal muscle atrophy in animals and humans. The antigravity calf soleus is a reference postural muscle to investigate the mechanism of disuse-induced maladaptation and plasticity of human and rodent (rats or mice skeletal musculature. Here, we report microgravity-induced global gene expression changes in space-flown mouse skeletal muscle and the identification of yet unknown disuse susceptible transcripts found in soleus (a mainly slow phenotype but not in extensor digitorum longus (a mainly fast phenotype dorsiflexor as functional counterpart to soleus. Adult C57Bl/N6 male mice (n = 5 flew aboard a biosatellite for 30 days on orbit (BION-M1 mission, 2013, a sex and age-matched cohort were housed in standard vivarium cages (n = 5, or in a replicate flight habitat as ground control (n = 5. Next to disuse atrophy signs (reduced size and myofiber phenotype I to II type shift as much as 680 differentially expressed genes were found in the space-flown soleus, and only 72 in extensor digitorum longus (only 24 genes in common compared to ground controls. Altered expression of gene transcripts matched key biological processes (contractile machinery, calcium homeostasis, muscle development, cell metabolism, inflammatory and oxidative stress response. Some transcripts (Fzd9, Casq2, Kcnma1, Ppara, Myf6 were further validated by quantitative real-time PCR (qRT-PCR. Besides previous reports on other leg muscle types we put forth for the first time a complete set of microgravity susceptible gene transcripts in soleus of mice as promising new biomarkers or targets for optimization of physical countermeasures and rehabilitation protocols to overcome disuse atrophy conditions in different clinical settings, rehabilitation and spaceflight.

Electrophysiological, histochemical, and hormonal adaptation of rat muscle after prolonged hindlimb suspension

Science.gov (United States)

Kourtidou-Papadeli, Chrysoula; Kyparos, Antonios; Albani, Maria; Frossinis, Athanasios; Papadelis, Christos L.; Bamidis, Panagiotis; Vivas, Ana; Guiba-Tziampiri, Olympia

2004-05-01

The perspective of long-duration flights for future exploration, imply more research in the field of human adaptation. Previous studies in rat muscles hindlimb suspension (HLS), indicated muscle atrophy and a change of fibre composition from slow-to-fast twitch types. However, the contractile responses to long-term unloading is still unclear. Fifteen adult Wistar rats were studied in 45 and 70 days of muscle unweighting and soleus (SOL) muscle as well as extensor digitorum longus (EDL) were prepared for electrophysiological recordings (single, twitch, tetanic contraction and fatigue) and histochemical stainings. The loss of muscle mass observed was greater in the soleus muscle. The analysis of electrophysiological properties of both EDL and SOL showed significant main effects of group, of number of unweighting days and fatigue properties. Single contraction for soleus muscle remained unchanged but there was statistically significant difference for tetanic contraction and fatigue. Fatigue index showed a decrease for the control rats, but increase for the HLS rats. According to the histochemical findings there was a shift from oxidative to glycolytic metabolism during HLS. The data suggested that muscles atrophied, but they presented an adaptation pattern, while their endurance in fatigue was decreased.

Satellite cell depletion prevents fiber hypertrophy in skeletal muscle.

Science.gov (United States)

Egner, Ingrid M; Bruusgaard, Jo C; Gundersen, Kristian

2016-08-15

The largest mammalian cells are the muscle fibers, and they have multiple nuclei to support their large cytoplasmic volumes. During hypertrophic growth, new myonuclei are recruited from satellite stem cells into the fiber syncytia, but it was recently suggested that such recruitment is not obligatory: overload hypertrophy after synergist ablation of the plantaris muscle appeared normal in transgenic mice in which most of the satellite cells were abolished. When we essentially repeated these experiments analyzing the muscles by immunohistochemistry and in vivo and ex vivo imaging, we found that overload hypertrophy was prevented in the satellite cell-deficient mice, in both the plantaris and the extensor digitorum longus muscles. We attribute the previous findings to a reliance on muscle mass as a proxy for fiber hypertrophy, and to the inclusion of a significant number of regenerating fibers in the analysis. We discuss that there is currently no model in which functional, sustainable hypertrophy has been unequivocally demonstrated in the absence of satellite cells; an exception is re-growth, which can occur using previously recruited myonuclei without addition of new myonuclei. © 2016. Published by The Company of Biologists Ltd.

Myostatin promotes distinct responses on protein metabolism of skeletal and cardiac muscle fibers of rodents

Directory of Open Access Journals (Sweden)

L.H. Manfredi

2017-10-01

Full Text Available Myostatin is a novel negative regulator of skeletal muscle mass. Myostatin expression is also found in heart in a much less extent, but it can be upregulated in pathological conditions, such as heart failure. Myostatin may be involved in inhibiting protein synthesis and/or increasing protein degradation in skeletal and cardiac muscles. Herein, we used cell cultures and isolated muscles from rats to determine protein degradation and synthesis. Muscles incubated with myostatin exhibited an increase in proteolysis with an increase of Atrogin-1, MuRF1 and LC3 genes. Extensor digitorum longus muscles and C2C12 myotubes exhibited a reduction in protein turnover. Cardiomyocytes showed an increase in proteolysis by activating autophagy and the ubiquitin proteasome system, and a decrease in protein synthesis by decreasing P70S6K. The effect of myostatin on protein metabolism is related to fiber type composition, which may be associated to the extent of atrophy mediated effect of myostatin on muscle.

Myostatin promotes distinct responses on protein metabolism of skeletal and cardiac muscle fibers of rodents.

Science.gov (United States)

Manfredi, L H; Paula-Gomes, S; Zanon, N M; Kettelhut, I C

2017-10-19

Myostatin is a novel negative regulator of skeletal muscle mass. Myostatin expression is also found in heart in a much less extent, but it can be upregulated in pathological conditions, such as heart failure. Myostatin may be involved in inhibiting protein synthesis and/or increasing protein degradation in skeletal and cardiac muscles. Herein, we used cell cultures and isolated muscles from rats to determine protein degradation and synthesis. Muscles incubated with myostatin exhibited an increase in proteolysis with an increase of Atrogin-1, MuRF1 and LC3 genes. Extensor digitorum longus muscles and C2C12 myotubes exhibited a reduction in protein turnover. Cardiomyocytes showed an increase in proteolysis by activating autophagy and the ubiquitin proteasome system, and a decrease in protein synthesis by decreasing P70S6K. The effect of myostatin on protein metabolism is related to fiber type composition, which may be associated to the extent of atrophy mediated effect of myostatin on muscle.

PLASTICITY OF SKELETAL MUSCLE STUDIED BY STEREOLOGY

Directory of Open Access Journals (Sweden)

Ida Eržen

2011-05-01

Full Text Available The present contribution provides an overview of stereological methods applied in the skeletal muscle research at the Institute of Anatomy of the Medical Faculty in Ljubljana. Interested in skeletal muscle plasticity we studied three different topics: (i expression of myosin heavy chain isoforms in slow and fast muscles under experimental conditions, (ii frequency of satellite cells in young and old human and rat muscles and (iii capillary supply of rat fast and slow muscles. We analysed the expression of myosin heavy chain isoforms within slow rat soleus and fast extensor digitorum longus muscles after (i homotopic and heterotopic transplantation of both muscles, (ii low frequency electrical stimulation of the fast muscle and (iii transposition of the fast nerve to the slow muscle. The models applied were able to turn the fast muscle into a completely slow muscle, but not vice versa. One of the indicators for the regenerative potential of skeletal muscles is its satellite cell pool. The estimated parameters, number of satellite cells per unit fibre length, corrected to the reference sarcomere length (Nsc/Lfib and number of satellite cells per number of nuclei (myonuclei and satellite cell nuclei (Nsc/Nnucl indicated that the frequency of M-cadherin stained satellite cells declines in healthy old human and rat muscles compared to young muscles. To access differences in capillary densities among slow and fast muscles and slow and fast muscle fibres, we have introduced Slicer and Fakir methods, and tested them on predominantly slow and fast rat muscles. Discussing three different topics that require different approach, the present paper reflects the three decades of the development of stereological methods: 2D analysis by simple point counting in the 70's, the disector in the 80's and virtual spatial probes in the 90's. In all methods the interactive computer assisted approach was utilised.

Role of adenosine 5'-monophosphate-activated protein kinase in interleukin-6 release from isolated mouse skeletal muscle

DEFF Research Database (Denmark)

Glund, Stephan; Treebak, Jonas Thue; Long, Yun Chau

2009-01-01

IL-6 is released from skeletal muscle during exercise and has consequently been implicated to mediate beneficial effects on whole-body metabolism. Using 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR), a pharmacological activator of 5'-AMP-activated protein kinase (AMPK), we tested......-type mice was also incubated with the AMPK activator A-769662. Incubation of mouse glycolytic extensor digitorum longus and oxidative soleus muscle for 2 h was associated with profound IL-6 mRNA production and protein release, which was suppressed by AICAR (P ... the hypothesis that AMPK modulates IL-6 release from isolated muscle. Skeletal muscle from AMPKalpha2 kinase-dead transgenic, AMPKalpha1 knockout (KO) and AMPKgamma3 KO mice and respective wild-type littermates was incubated in vitro, in the absence or presence of 2 mmol/liter AICAR. Skeletal muscle from wild...

Insulin binding to individual rat skeletal muscles

International Nuclear Information System (INIS)

Koerker, D.J.; Sweet, I.R.; Baskin, D.G.

1990-01-01

Studies of insulin binding to skeletal muscle, performed using sarcolemmal membrane preparations or whole muscle incubations of mixed muscle or typical red (soleus, psoas) or white [extensor digitorum longus (EDL), gastrocnemius] muscle, have suggested that red muscle binds more insulin than white muscle. We have evaluated this hypothesis using cryostat sections of unfixed tissue to measure insulin binding in a broad range of skeletal muscles; many were of similar fiber-type profiles. Insulin binding per square millimeter of skeletal muscle slice was measured by autoradiography and computer-assisted densitometry. We found a 4.5-fold range in specific insulin tracer binding, with heart and predominantly slow-twitch oxidative muscles (SO) at the high end and the predominantly fast-twitch glycolytic (FG) muscles at the low end of the range. This pattern reflects insulin sensitivity. Evaluation of displacement curves for insulin binding yielded linear Scatchard plots. The dissociation constants varied over a ninefold range (0.26-2.06 nM). Binding capacity varied from 12.2 to 82.7 fmol/mm2. Neither binding parameter was correlated with fiber type or insulin sensitivity; e.g., among three muscles of similar fiber-type profile, the EDL had high numbers of low-affinity binding sites, whereas the quadriceps had low numbers of high-affinity sites. In summary, considerable heterogeneity in insulin binding was found among hindlimb muscles of the rat, which can be attributed to heterogeneity in binding affinities and the numbers of binding sites. It can be concluded that a given fiber type is not uniquely associated with a set of insulin binding parameters that result in high or low binding

Metabolomic Analysis of Oxidative and Glycolytic Skeletal Muscles by Matrix-Assisted Laser Desorption/IonizationMass Spectrometric Imaging (MALDI MSI)

Science.gov (United States)

Tsai, Yu-Hsuan; Garrett, Timothy J.; Carter, Christy S.; Yost, Richard A.

2015-06-01

Skeletal muscles are composed of heterogeneous muscle fibers that have different physiological, morphological, biochemical, and histological characteristics. In this work, skeletal muscles extensor digitorum longus, soleus, and whole gastrocnemius were analyzed by matrix-assisted laser desorption/ionization mass spectrometry to characterize small molecule metabolites of oxidative and glycolytic muscle fiber types as well as to visualize biomarker localization. Multivariate data analysis such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed to extract significant features. Different metabolic fingerprints were observed from oxidative and glycolytic fibers. Higher abundances of biomolecules such as antioxidant anserine as well as acylcarnitines were observed in the glycolytic fibers, whereas taurine and some nucleotides were found to be localized in the oxidative fibers.

Fibre type composition of soleus and extensor digitorum longus muscles in normal female inbred Lewis rats

Czech Academy of Sciences Publication Activity Database

Soukup, Tomáš; Zachařová, Gisela; Smerdu, V.

2002-01-01

Roč. 104, č. 4 (2002), s. 399-405 ISSN 0065-1281 R&D Projects: GA ČR GA304/00/1653 Grant - others:CZ - SI Czech-Slovenian Intergovernmental S&T Co-operation(XC) - Institutional research plan: CEZ:AV0Z5011922 Keywords : inbred Lewis rats * skeletal muscles * soleus and EDL muscles Subject RIV: FH - Neurology Impact factor: 0.867, year: 2002

The lumbrical muscle: a novel in situ system to evaluate adult skeletal muscle proteolysis and anticatabolic drugs for therapeutic purposes.

Science.gov (United States)

Bergantin, Leandro Bueno; Figueiredo, Leonardo Bruno; Godinho, Rosely Oliveira

2011-12-01

The molecular regulation of skeletal muscle proteolysis and the pharmacological screening of anticatabolic drugs have been addressed by measuring tyrosine release from prepubertal rat skeletal muscles, which are thin enough to allow adequate in vitro diffusion of oxygen and substrates. However, the use of muscle at accelerated prepubertal growth has limited the analysis of adult muscle proteolysis or that associated with aging and neurodegenerative diseases. Here we established the adult rat lumbrical muscle (4/hindpaw; 8/rat) as a new in situ experimental model for dynamic measurement of skeletal muscle proteolysis. By incubating lumbrical muscles attached to their individual metatarsal bones in Tyrode solution, we showed that the muscle proteolysis rate of adult and aged rats (3-4 to 24 mo old) is 45-25% of that in prepubertal animals (1 mo old), which makes questionable the usual extrapolation of proteolysis from prepubertal to adult/senile muscles. While acute mechanical injury or 1- to 7-day denervation increased tyrosine release from adult lumbrical muscle by up to 60%, it was reduced by 20-28% after 2-h incubation with β-adrenoceptor agonists, forskolin or phosphodiesterase inhibitor IBMX. Using inhibitors of 26S-proteasome (MG132), lysosome (methylamine), or calpain (E64/leupeptin) systems, we showed that ubiquitin-proteasome is accountable for 40-50% of total lumbrical proteolysis of adult, middle-aged, and aged rats. In conclusion, the lumbrical model allows the analysis of muscle proteolysis rate from prepubertal to senile rats. By permitting eight simultaneous matched measurements per rat, the new model improves similar protocols performed in paired extensor digitorum longus (EDL) muscles from prepubertal rats, optimizing the pharmacological screening of drugs for anticatabolic purposes.

Role of adenosine 5'-monophosphate-activated protein kinase subunits in skeletal muscle mammalian target of rapamycin signaling

DEFF Research Database (Denmark)

Deshmukh, Atul S.; Treebak, Jonas Thue; Long, Yun Chau

2008-01-01

AMP-activated protein kinase (AMPK) is an important energy-sensing protein in skeletal muscle. Mammalian target of rapamycin (mTOR) mediates translation initiation and protein synthesis through ribosomal S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1). AMPK...... activation reduces muscle protein synthesis by down-regulating mTOR signaling, whereas insulin mediates mTOR signaling via Akt activation. We hypothesized that AMPK-mediated inhibitory effects on mTOR signaling depend on catalytic alpha2 and regulatory gamma3 subunits. Extensor digitorum longus muscle from...... (Thr37/46) (P mTOR targets, suggesting mTOR signaling is blocked by prior AMPK activation. The AICAR-induced inhibition was partly rescued...

The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

International Nuclear Information System (INIS)

Hamrick, Mark W.; Herberg, Samuel; Arounleut, Phonepasong; He, Hong-Zhi; Shiver, Austin; Qi, Rui-Qun; Zhou, Li; Isales, Carlos M.

2010-01-01

Research highlights: → Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. → We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. → Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. → Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient-related hormones such as leptin

The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

Energy Technology Data Exchange (ETDEWEB)

Hamrick, Mark W., E-mail: mhamrick@mail.mcg.edu [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Herberg, Samuel; Arounleut, Phonepasong [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); He, Hong-Zhi [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Shiver, Austin [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Qi, Rui-Qun [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Zhou, Li [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Department of Internal Medicine, Henry Ford Health System, Detroit, MI (United States); Isales, Carlos M. [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); others, and

2010-09-24

Research highlights: {yields} Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. {yields} We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. {yields} Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. {yields} Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient

Rac1 is a novel regulator of contraction-stimulated glucose uptake in skeletal muscle.

Science.gov (United States)

Sylow, Lykke; Jensen, Thomas E; Kleinert, Maximilian; Mouatt, Joshua R; Maarbjerg, Stine J; Jeppesen, Jacob; Prats, Clara; Chiu, Tim T; Boguslavsky, Shlomit; Klip, Amira; Schjerling, Peter; Richter, Erik A

2013-04-01

In skeletal muscle, the actin cytoskeleton-regulating GTPase, Rac1, is necessary for insulin-dependent GLUT4 translocation. Muscle contraction increases glucose transport and represents an alternative signaling pathway to insulin. Whether Rac1 is activated by muscle contraction and regulates contraction-induced glucose uptake is unknown. Therefore, we studied the effects of in vivo exercise and ex vivo muscle contractions on Rac1 signaling and its regulatory role in glucose uptake in mice and humans. Muscle Rac1-GTP binding was increased after exercise in mice (~60-100%) and humans (~40%), and this activation was AMP-activated protein kinase independent. Rac1 inhibition reduced contraction-stimulated glucose uptake in mouse muscle by 55% in soleus and by 20-58% in extensor digitorum longus (EDL; P contraction-stimulated increment in glucose uptake was decreased by 27% (P = 0.1) and 40% (P muscles, respectively, of muscle-specific inducible Rac1 knockout mice. Furthermore, depolymerization of the actin cytoskeleton decreased contraction-stimulated glucose uptake by 100% and 62% (P muscles, respectively. These are the first data to show that Rac1 is activated during muscle contraction in murine and human skeletal muscle and suggest that Rac1 and possibly the actin cytoskeleton are novel regulators of contraction-stimulated glucose uptake.

The muscle CT of thigh in chronic Werdnig-Hoffmann disease

International Nuclear Information System (INIS)

Horikawa, Hirosei; Konagaya, Masaaki; Takayanagi, Tetsuya; Otsuji, Hideaki

1986-01-01

In this paper, the muscle CT of thigh in chronic Werdnig-Hoffmann disease (chronic WH) was evaluated. The subjects were five cases of chronic WH (3 males and 2 females, ages ranging from 6 to 22 years) and four control males. All cases showed symmetrical muscular weakness. The proximal muscle were more affected than the distal in the upper limbs. But the muscle strength of hip adduction was relatively spared as compared with other strength of lower limbs. The CT scan was carried out at the upper quarter level between lesser trochanter and medial condyle of the femur. The muscle CT of cases aged 6 and 7 years showed the severely decreased cross-sectional area of muscle without significant decrease in density. The atrophic muscles were surrounded by a large amount of low density area. The hamstring muscles and the adductor muscles, especially adductor longus muscle (ALM), were less affected than the quadriceps femoris muscles. Spotty and moth-eaten low density areas were observed dominantly in the severely affected muscles. In the advanced cases, only ALM could be identified on the CT image. The other muscles were unable to be identified because of severe atrophy with extremely low density. These CT findings suggest the process of muscular wastings of chronic WH as follows; at first muscle fibers are atrophied due to denervation and sooner or later replaced with fat tissue. Moreover, the preservation of ALM suggests that loss of anterior horn cells does not always go on homogeneously. (author)

Spatial and temporal aspects of muscle hyperalgesia induced by nerve growth factor in humans

DEFF Research Database (Denmark)

Andersen, H.; Arendt-Nielsen, L.; Svensson, P.

2008-01-01

longus and at the web between 1st and 2nd metatarsal (central involvement). One day after the NGF/control injections, hypertonic saline (0.5 ml, 5.8%) was injected into the left and right TA to study the pain response to chemical stimulation of the hyperalgesic muscle tissue. Scores on a modified Likert...... distribution of muscle hyperalgesia over time (immediately after, 3 h, 1, 4, 7 and 21 days) after injecting NGF (5 mu g) into the tibialis anterior (TA) muscle, to explore possibly involved central pain mechanisms and to investigate the effect of gender on development of hyperalgesia. Totally 20 healthy...... scale were used to assess soreness during muscle function. An area of hyperalgesia was observed locally at the injected site 3 h after injection of NGF, which expanded both proximally and distally on day 1; this effect subsided on day 4. Decreased PPT was also found between 1st and 2nd metatarsal on day...

Metabolism of branched-chain amino acids in leg muscles from tail-cast suspended intact and adrenalectomized rats

Science.gov (United States)

Jaspers, Stephen R.; Henriksen, Erik; Jacob, Stephan; Tischler, Marc E.

1989-01-01

The effects of muscle unloading, adrenalectomy, and cortisol treatment on the metabolism of branched-chain amino acids in the soleus and extensor digitorum longus of tail-cast suspended rats were investigated using C-14-labeled lucine, isoleucine, and valine in incubation studies. It was found that, compared to not suspended controls, the degradation of branched-chain amino acids in hind limb muscles was accelerated in tail-cast suspended rats. Adrenalectomy was found to abolish the aminotransferase flux and to diminish the dehydrogenase flux in the soleus. The data also suggest that cortisol treatment increases the rate of metabolism of branched-chain amino acids at the dehydrogenase step.

Changes of contractile responses due to simulated weightlessness in rat soleus muscle

Science.gov (United States)

Elkhammari, A.; Noireaud, J.; Léoty, C.

1994-08-01

Some contractile and electrophysiological properties of muscle fibers isolated from the slow-twitch soleus (SOL) and fast-twitch extensor digitorum longus (EDL) muscles of rats were compared with those measured in SOL muscles from suspended rats. In suspendede SOL (21 days of tail-suspension) membrane potential (Em), intracellular sodium activity (aiNa) and the slope of the relationship between Em and log [K]o were typical of fast-twitch muscles. The relation between the maximal amplitude of K-contractures vs Em was steeper for control SOL than for EDL and suspended SOL muscles. After suspension, in SOL muscles the contractile threshold and the inactivation curves for K-contractures were shifted to more positive Em. Repriming of K-contractures was unaffected by suspencion. The exposure of isolated fibers to perchlorate (ClO4-)-containing (6-40 mM) solutions resulted ina similar concentration-dependent shift to more negative Em of activation curves for EDL and suspended SOL muscles. On exposure to a Na-free TEA solution, SOL from control and suspended rats, in contrast to EDL muscles, generated slow contractile responses. Suspended SOL showed a reduced sensitivity to the contracture-producing effect of caffeine compared to control muscles. These results suggested that the modification observed due to suspension could be encounted by changes in the characteristics of muscle fibers from slow to fast-twitch type.

Effects of 12-wk eccentric calf muscle training on muscle-tendon glucose uptake and SEMG in patients with chronic Achilles tendon pain

DEFF Research Database (Denmark)

Masood, Tahir; Kalliokoski, Kari; Magnusson, S Peter

2014-01-01

High-load eccentric exercises have been a key component in the conservative management of chronic Achilles tendinopathy. This study investigated the effects of a 12-wk progressive, home-based eccentric rehabilitation program on ankle plantar flexors' glucose uptake (GU) and myoelectric activity......, while the asymptomatic leg displayed higher uptake for medial gastrocnemius and flexor hallucis longus (P tendon GU than the controls (P effect on the tendon GU. Concerning SEMG, at baseline, soleus showed more relative...... within- or between-group differences. Eccentric rehabilitation was effective in decreasing subjective severity of Achilles tendinopathy. It also resulted in redistribution of relative electrical activity, but not metabolic activity, within the triceps surae muscle....

β-Hydroxy-β-methylbutyrate (HMβ supplementation stimulates skeletal muscle hypertrophy in rats via the mTOR pathway

Directory of Open Access Journals (Sweden)

Pimentel Gustavo D

2011-02-01

Full Text Available Abstract β-Hydroxy-β-methylbutyrate (HMβ supplementation is used to treat cancer, sepsis and exercise-induced muscle damage. However, its effects on animal and human health and the consequences of this treatment in other tissues (e.g., fat and liver have not been examined. The purpose of this study was to evaluate the effects of HMβ supplementation on skeletal muscle hypertrophy and the expression of proteins involved in insulin signalling. Rats were treated with HMβ (320 mg/kg body weight or saline for one month. The skeletal muscle hypertrophy and insulin signalling were evaluated by western blotting, and hormonal concentrations were evaluated using ELISAs. HMβ supplementation induced muscle hypertrophy in the extensor digitorum longus (EDL and soleus muscles and increased serum insulin levels, the expression of the mammalian target of rapamycin (mTOR and phosphorylation of p70S6K in the EDL muscle. Expression of the insulin receptor was increased only in liver. Thus, our results suggest that HMβ supplementation can be used to increase muscle mass without adverse health effects.

Comparative Analysis of Muscle Hypertrophy Models Reveals Divergent Gene Transcription Profiles and Points to Translational Regulation of Muscle Growth through Increased mTOR Signaling

Directory of Open Access Journals (Sweden)

Marcelo G. Pereira

2017-12-01

Full Text Available Skeletal muscle mass is a result of the balance between protein breakdown and protein synthesis. It has been shown that multiple conditions of muscle atrophy are characterized by the common regulation of a specific set of genes, termed atrogenes. It is not known whether various models of muscle hypertrophy are similarly regulated by a common transcriptional program. Here, we characterized gene expression changes in three different conditions of muscle growth, examining each condition during acute and chronic phases. Specifically, we compared the transcriptome of Extensor Digitorum Longus (EDL muscles collected (1 during the rapid phase of postnatal growth at 2 and 4 weeks of age, (2 24 h or 3 weeks after constitutive activation of AKT, and (3 24 h or 3 weeks after overload hypertrophy caused by tenotomy of the Tibialis Anterior muscle. We observed an important overlap between significantly regulated genes when comparing each single condition at the two different timepoints. Furthermore, examining the transcriptional changes occurring 24 h after a hypertrophic stimulus, we identify an important role for genes linked to a stress response, despite the absence of muscle damage in the AKT model. However, when we compared all different growth conditions, we did not find a common transcriptional fingerprint. On the other hand, all conditions showed a marked increase in mTORC1 signaling and increased ribosome biogenesis, suggesting that muscle growth is characterized more by translational, than transcriptional regulation.

Skeletal Muscle-specific G Protein-coupled Receptor Kinase 2 Ablation Alters Isolated Skeletal Muscle Mechanics and Enhances Clenbuterol-stimulated Hypertrophy.

Science.gov (United States)

Woodall, Benjamin P; Woodall, Meryl C; Luongo, Timothy S; Grisanti, Laurel A; Tilley, Douglas G; Elrod, John W; Koch, Walter J

2016-10-14

GRK2, a G protein-coupled receptor kinase, plays a critical role in cardiac physiology. Adrenergic receptors are the primary target for GRK2 activity in the heart; phosphorylation by GRK2 leads to desensitization of these receptors. As such, levels of GRK2 activity in the heart directly correlate with cardiac contractile function. Furthermore, increased expression of GRK2 after cardiac insult exacerbates injury and speeds progression to heart failure. Despite the importance of this kinase in both the physiology and pathophysiology of the heart, relatively little is known about the role of GRK2 in skeletal muscle function and disease. In this study we generated a novel skeletal muscle-specific GRK2 knock-out (KO) mouse (MLC-Cre:GRK2 fl/fl ) to gain a better understanding of the role of GRK2 in skeletal muscle physiology. In isolated muscle mechanics testing, GRK2 ablation caused a significant decrease in the specific force of contraction of the fast-twitch extensor digitorum longus muscle yet had no effect on the slow-twitch soleus muscle. Despite these effects in isolated muscle, exercise capacity was not altered in MLC-Cre:GRK2 fl/fl mice compared with wild-type controls. Skeletal muscle hypertrophy stimulated by clenbuterol, a β 2 -adrenergic receptor (β 2 AR) agonist, was significantly enhanced in MLC-Cre:GRK2 fl/fl mice; mechanistically, this seems to be due to increased clenbuterol-stimulated pro-hypertrophic Akt signaling in the GRK2 KO skeletal muscle. In summary, our study provides the first insights into the role of GRK2 in skeletal muscle physiology and points to a role for GRK2 as a modulator of contractile properties in skeletal muscle as well as β 2 AR-induced hypertrophy. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Skeletal Muscle-specific G Protein-coupled Receptor Kinase 2 Ablation Alters Isolated Skeletal Muscle Mechanics and Enhances Clenbuterol-stimulated Hypertrophy*

Science.gov (United States)

Woodall, Benjamin P.; Woodall, Meryl C.; Luongo, Timothy S.; Grisanti, Laurel A.; Tilley, Douglas G.; Elrod, John W.; Koch, Walter J.

2016-01-01

GRK2, a G protein-coupled receptor kinase, plays a critical role in cardiac physiology. Adrenergic receptors are the primary target for GRK2 activity in the heart; phosphorylation by GRK2 leads to desensitization of these receptors. As such, levels of GRK2 activity in the heart directly correlate with cardiac contractile function. Furthermore, increased expression of GRK2 after cardiac insult exacerbates injury and speeds progression to heart failure. Despite the importance of this kinase in both the physiology and pathophysiology of the heart, relatively little is known about the role of GRK2 in skeletal muscle function and disease. In this study we generated a novel skeletal muscle-specific GRK2 knock-out (KO) mouse (MLC-Cre:GRK2fl/fl) to gain a better understanding of the role of GRK2 in skeletal muscle physiology. In isolated muscle mechanics testing, GRK2 ablation caused a significant decrease in the specific force of contraction of the fast-twitch extensor digitorum longus muscle yet had no effect on the slow-twitch soleus muscle. Despite these effects in isolated muscle, exercise capacity was not altered in MLC-Cre:GRK2fl/fl mice compared with wild-type controls. Skeletal muscle hypertrophy stimulated by clenbuterol, a β2-adrenergic receptor (β2AR) agonist, was significantly enhanced in MLC-Cre:GRK2fl/fl mice; mechanistically, this seems to be due to increased clenbuterol-stimulated pro-hypertrophic Akt signaling in the GRK2 KO skeletal muscle. In summary, our study provides the first insights into the role of GRK2 in skeletal muscle physiology and points to a role for GRK2 as a modulator of contractile properties in skeletal muscle as well as β2AR-induced hypertrophy. PMID:27566547

Enzyme replacement therapy rescues weakness and improves muscle pathology in mice with X-linked myotubular myopathy.

Science.gov (United States)

Lawlor, Michael W; Armstrong, Dustin; Viola, Marissa G; Widrick, Jeffrey J; Meng, Hui; Grange, Robert W; Childers, Martin K; Hsu, Cynthia P; O'Callaghan, Michael; Pierson, Christopher R; Buj-Bello, Anna; Beggs, Alan H

2013-04-15

No effective treatment exists for patients with X-linked myotubular myopathy (XLMTM), a fatal congenital muscle disease caused by deficiency of the lipid phosphatase, myotubularin. The Mtm1δ4 and Mtm1 p.R69C mice model severely and moderately symptomatic XLMTM, respectively, due to differences in the degree of myotubularin deficiency. Contractile function of intact extensor digitorum longus (EDL) and soleus muscles from Mtm1δ4 mice, which produce no myotubularin, is markedly impaired. Contractile forces generated by chemically skinned single fiber preparations from Mtm1δ4 muscle were largely preserved, indicating that weakness was largely due to impaired excitation contraction coupling. Mtm1 p.R69C mice, which produce small amounts of myotubularin, showed impaired contractile function only in EDL muscles. Short-term replacement of myotubularin with a prototypical targeted protein replacement agent (3E10Fv-MTM1) in Mtm1δ4 mice improved contractile function and muscle pathology. These promising findings suggest that even low levels of myotubularin protein replacement can improve the muscle weakness and reverse the pathology that characterizes XLMTM.

Skeletal muscle water T2 as a biomarker of disease status and exercise effects in patients with Duchenne muscular dystrophy.

Science.gov (United States)

Mankodi, Ami; Azzabou, Noura; Bulea, Thomas; Reyngoudt, Harmen; Shimellis, Hirity; Ren, Yupeng; Kim, Eunhee; Fischbeck, Kenneth H; Carlier, Pierre G

2017-08-01

The purpose of this study was to examine exercise effects on muscle water T 2 in patients with Duchenne muscular dystrophy (DMD). In 12 DMD subjects and 19 controls, lower leg muscle fat (%) was measured by Dixon and muscle water T 2 and R 2 (1/T 2 ) by the tri-exponential model. Muscle water R 2 was measured again at 3 hours after an ankle dorsiflexion exercise. The muscle fat fraction was higher in DMD participants than in controls (p muscle. Muscle water T 2 was measured independent of the degree of fatty degeneration in DMD muscle. At baseline, muscle water T 2 was higher in all but the extensor digitorum longus muscles of DMD participants than controls (p muscle torque (p muscle water R 2 decreased (T 2 increased) after exercise from baseline in DMD subjects and controls with greater changes in the target muscles of the exercise than in ankle plantarflexor muscles. Skeletal muscle water T 2 is a sensitive biomarker of the disease status in DMD and of the exercise response in DMD patients and controls. Published by Elsevier B.V.

Fiber type composition of unoperated rat soleus and extensor digitorum longus muscles after unilateral isotransplantation of a foreign muscle in long-term experiments

Czech Academy of Sciences Publication Activity Database

Soukup, Tomáš; Smerdu, V.; Zachařová, Gisela

2009-01-01

Roč. 58, č. 2 (2009), s. 253-262 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/05/0327; GA ČR(CZ) GA304/08/0256; GA MŠk(CZ) LC554 Grant - others:EC(XE) LSH-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : muscle transplantations * muscle fiber types * myosin heavy chains Subject RIV: ED - Physiology Impact factor: 1.430, year: 2009

[Reconstruction of chronic Achilles tendon rupture with flexor hallucis longus tendon harvested using a minimally invasive technique].

Science.gov (United States)

Miao, Xudong; Wu, Yongping; Tao, Huimin; Yang, Disheng

2011-07-01

To evaluate the effectiveness of flexor hallucis longus tendon harvested using a minimally invasive technique in reconstruction of chronic Achilles tendon rupture. Between July 2006 and December 2009, 22 patients (22 feet) with chronic Achilles tendon rupture were treated, including 16 males and 6 females with a median age of 48 years (range, 28-65 years). The disease duration was 27-1,025 days (median, 51 days). Twenty-one patients had hooflike movement's history and 1 patient had no obvious inducement. The result of Thompson test was positive in 22 cases. The score was 53.04 +/- 6.75 according to American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score system. MRI indicated that the gap of the chronic Achilles tendon rupture was 4.2-8.0 cm. A 3 cm-long incision was made vertically in the plantar aspect of the midfoot and a 1 cm-long transverse incision was made in a plantar flexor crease at the base of the great toe to harvest flexor hallucis longus tendon. The flexor hallucis longus tendon was 10.5-13.5 cm longer from tuber calcanei to the end of the Achilles tendon, and then the tendon was fixed to the tuber calcanei using interface screws or anchor nail after they were woven to form reflexed 3-bundle and sutured. Wound healed by first intention in all patients and no early complication occurred. Twenty-two patients were followed up 12-42 months (mean, 16.7 months). At 12 months after operation, The AOFAS ankle and hindfoot score was 92.98 +/- 5.72, showing significant difference when compared with that before operation (t= -40.903, P=0.000). The results were excellent in 18 cases, good in 2 cases, and fair in 2 cases with an excellent and good rate of 90.9%. No sural nerve injury, posterior tibial nerve injury, plantar painful scar, medial plantar nerve injury, and lateral plantar nerve injury occurred. Chronic Achilles tendon rupture reconstruction with flexor hallucis longus tendon harvested using a minimally invasive technique offers a

Optimal workloop energetics of muscle-actuated systems: an impedance matching view.

Directory of Open Access Journals (Sweden)

Waleed A Farahat

2010-06-01

Full Text Available Integrative approaches to studying the coupled dynamics of skeletal muscles with their loads while under neural control have focused largely on questions pertaining to the postural and dynamical stability of animals and humans. Prior studies have focused on how the central nervous system actively modulates muscle mechanical impedance to generate and stabilize motion and posture. However, the question of whether muscle impedance properties can be neurally modulated to create favorable mechanical energetics, particularly in the context of periodic tasks, remains open. Through muscle stiffness tuning, we hypothesize that a pair of antagonist muscles acting against a common load may produce significantly more power synergistically than individually when impedance matching conditions are met between muscle and load. Since neurally modulated muscle stiffness contributes to the coupled muscle-load stiffness, we further anticipate that power-optimal oscillation frequencies will occur at frequencies greater than the natural frequency of the load. These hypotheses were evaluated computationally by applying optimal control methods to a bilinear muscle model, and also evaluated through in vitro measurements on frog Plantaris longus muscles acting individually and in pairs upon a mass-spring-damper load. We find a 7-fold increase in mechanical power when antagonist muscles act synergistically compared to individually at a frequency higher than the load natural frequency. These observed behaviors are interpreted in the context of resonance tuning and the engineering notion of impedance matching. These findings suggest that the central nervous system can adopt strategies to harness inherent muscle impedance in relation to external loads to attain favorable mechanical energetics.

Interval training by normobaric hypoxia accelerates the reinnervation of musculus extensor digitorum longus in mice

DEFF Research Database (Denmark)

Vardya, Irina; (Vard'ya); Mospanova, Svetlana V.

2000-01-01

Dokl Biol Sci. 2000 Mar-Apr;371:112-4. Interval training by normobaric hypoxia accelerates the reinnervation of musculus extensor digitorum longus in mice. Vard'ya IV , Mospanova SV , Portnov VV , Balezina OP , Koshelev VB . Department of Human and Animal Physiology, Faculty of Biology, Moscow St...... State University, Russia. PMID: 10833635 [PubMed - indexed for MEDLINE] Udgivelsesdato: 2000...

Heat production during contraction in skeletal muscle of hypothyroid mice

Energy Technology Data Exchange (ETDEWEB)

Leijendekker, W.J.; van Hardeveld, C.; Elzinga, G. (Free Univ., Amsterdam (Netherlands))

1987-08-01

The effect of hypothyroidism on tension-independent and -dependent heat produced during a twitch and a tetanic contraction of extensor digitorum longus (EDL) and soleus muscle of mice was examined. The amount of heat produced during a twitch and the rate of heat development during a tetanus of EDL and soleus were measured at and above optimal length. The effect of hypothyroidism on force production was <30%. Straight lines were used to fit the relation between heat production and force. Hypothyroidism significantly decreases tension-independent heat during contraction of EDL and soleus muscle. Because the tension-independent heat is considered to be related to the Ca{sup 2+} cycling, these findings suggest that ATP splitting due to the Ca{sup 2+} cycling is reduced in hypothyroid mice. This conclusion was strengthened by the observation that the oxalate-supported {sup 45}Ca{sup 2+}-uptake activity and {sup 45}Ca{sup 2+}-loading capacity of muscle homogenates from hypothyroid mice were reduced, respectively, to 51 and to 65% in soleus and to 63 and 73% in EDL muscle as compared with euthyroid mice. The tension-dependent rate of heat development during a tetanus was also decreased in soleus muscle of hypothyroid mice. This suggests a lower rate of ATP hydrolysis related to cross-bridge cycling in this muscle due to the hypothyroid state.

Physiological studies of muscle rigor mortis in the fowl

International Nuclear Information System (INIS)

Nakahira, S.; Kaneko, K.; Tanaka, K.

1990-01-01

A simple system was developed for continuous measurement of muscle contraction during nor mortis. Longitudinal muscle strips dissected from the Peroneus Longus were suspended in a plastic tube containing liquid paraffin. Mechanical activity was transmitted to a strain-gauge transducer which is connected to a potentiometric pen-recorder. At the onset of measurement 1.2g was loaded on the muscle strip. This model was used to study the muscle response to various treatments during nor mortis. All measurements were carried out under the anaerobic condition at 17°C, except otherwise stated. 1. The present system was found to be quite useful for continuous measurement of muscle rigor course. 2. Muscle contraction under the anaerobic condition at 17°C reached a peak about 2 hours after the onset of measurement and thereafter it relaxed at a slow rate. In contrast, the aerobic condition under a high humidity resulted in a strong rigor, about three times stronger than that in the anaerobic condition. 3. Ultrasonic treatment (37, 000-47, 000Hz) at 25°C for 10 minutes resulted in a moderate muscle rigor. 4. Treatment of muscle strip with 2mM EGTA at 30°C for 30 minutes led to a relaxation of the muscle. 5. The muscle from the birds killed during anesthesia with pentobarbital sodium resulted in a slow rate of rigor, whereas the birds killed one day after hypophysectomy led to a quick muscle rigor as seen in intact controls. 6. A slight muscle rigor was observed when muscle strip was placed in a refrigerator at 0°C for 18.5 hours and thereafter temperature was kept at 17°C. (author)

[Reconstruction of the extensor pollicis longus tendon by transposition of the extensor indicis tendon].

Science.gov (United States)

Loos, A; Kalb, K; Van Schoonhoven, J; Landsleitner Dagger, B

2003-12-01

Rupture of the extensor pollicis longus-tendon (EPL) is a frequent complication after distal radius fractures. Other traumatic and non-traumatic reasons for this tendon lesion are known, including a theory about a disorder in the blood supply to the tendon itself. We examined 40 patients after reconstruction of the EPL-tendon in a mean follow-up time of 30 months. All patients were clinically examined and a DASH questionnaire was answered by all patients. The method to reconstruct the EPL-tendon was the transposition of the extensor indicis-tendon. After the operations the thumb was put in a splint for four weeks in a "hitch-hiker's-position". 31 ruptures of the tendon (77.5 %) were a result of trauma. In 20 of them (50 %) a distal radius fracture had occurred. Clinical examination included measurements of the movement of the thumb- and index-finger joints, the grip strength and the maximal span of the hand. Significant differences were not found. The isolated extension of the index finger was possible in all patients. But it was reduced in ten cases which represent 25 %. Our results were evaluated by the Geldmacher score to evaluate the reconstruction of the EPL-tendon. 20 % excellent, 65 % good, 12.5 % fair and 2.5 % poor results were reached. The Geldmacher score was used critically. We suggest its modification for the evaluation of thumb abduction. The DASH score reached a functional value of ten points which represents a very good result. In conclusion the extensor indicis-transposition is a safe method to reconstruct the EPL-tendon. Its substantial advantage is taking a healthy muscle as the motor, thereby avoiding the risk of using a degenerated muscle in late tendon reconstruction. A powerful extension of the index finger will be maintained by physical education. Generally, the loss of the extension of the index finger is negligible. It does not disturb the patients. But it has to be discussed with the patient before the operation.

Rectus abdominis muscle injuries in elite handball players: management and rehabilitation

Science.gov (United States)

Balius, Ramon; Pedret, Carles; Pacheco, Laura; Gutierrez, Josep Antoni; Vives, Joan; Escoda, Jaume

2011-01-01

Muscle injuries generally occur in two-joint muscles with a high percentage of type II fibers during the performance of eccentric activity. Some muscle injuries, such as those located in the adductor longus, a monoarticular muscle, as well as rectus abdominis do not fully comply with these requirements. This study examines five cases of elite handball players with ruptured rectus abdominals. Sonographically, lesions in rectus abdominis are shown as a disruption of the fibrillar pattern with a hematic suffusion that invades the entire lesion. In some of the cases, the ultrasound study was complemented with a MRI. A unified rehabilitation protocol was applied and the return to play time of each handball player ranged between 16 and 22 days, with an average of 18.2 days. Follow-up at 15 months showed no evidence of re-injury or residual discomfort and all of them are playing at their highest level. The aim of this study was to illustrate a feature of handball injury that, as in tennis and volleyball, is uncommon and so far has not been specifically reported. The phenomenon of contralateral abdominal hypertrophy in handball appears in the dominant arm as in tennis and volleyball. PMID:24198573

Role of Glucocorticoids in the Response to Unloading of Muscle Protein and Amino Acid Metabolism

Science.gov (United States)

Tischler, M. E.; Jaspers, S. R.

1985-01-01

Intact control (weight bearing) and suspended rats gained weight at a similar rate during a 6 day period. Adrenaectomized (adx) weight bearing rats gained less weight during this period while adrenalectomized suspended rats showed no significant weight gain. Cortisol treatment of both of these groups of animals caused a loss of body weight. Results from these studies show several important findings: (1) Metabolic changes in the extensor digitorum longus muscle of suspended rats are due primarily to increased circulating gluccorticoids; (2) Metabolic changes in the soleus due to higher steroid levels are probably potentiated by greater numbers of receptors; and (3) Not all metabolic responses in the unloaded soleus muscle are due to direct action of elevated glucocorticoids or increased sensitivity to these hormones.

Passive stiffness of monoarticular lower leg muscles is influenced by knee joint angle.

Science.gov (United States)

Ateş, Filiz; Andrade, Ricardo J; Freitas, Sandro R; Hug, François; Lacourpaille, Lilian; Gross, Raphael; Yucesoy, Can A; Nordez, Antoine

2018-03-01

While several studies demonstrated the occurrence of intermuscular mechanical interactions, the physiological significance of these interactions remains a matter of debate. The purpose of this study was to quantify the localized changes in the shear modulus of the gastrocnemius lateralis (GL), monoarticular dorsi- and plantar-flexor muscles induced by a change in knee angle. Participants underwent slow passive ankle rotations at the following two knee positions: knee flexed at 90° and knee fully extended. Ultrasound shear wave elastography was used to assess the muscle shear modulus of the GL, soleus [both proximally (SOL-proximal) and distally (SOL distal)], peroneus longus (PERL), and tibialis anterior (TA). This was performed during two experimental sessions (experiment I: n = 11; experiment II: n = 10). The shear modulus of each muscle was compared between the two knee positions. The shear modulus was significantly higher when the knee was fully extended than when the knee was flexed (P passive muscle force, these results provide evidence of a non-negligible intermuscular mechanical interaction between the human lower leg muscles during passive ankle rotations. The role of these interactions in the production of coordinated movements requires further investigation.

Complications arising from a misdiagnosed giant lipoma of the hand and palm: a case report

Directory of Open Access Journals (Sweden)

Pagonis Thomas

2011-11-01

Full Text Available Abstract Introduction Lipomas are benign tumors which may appear in almost any human organ. Their diagnosis rate in the hand region is not known. Case Presentation We present the case of a 63-year-old Greek Caucasian woman with a giant lipoma of the hand and palm which was not initially diagnosed. After repeated surgical decompression of the carpal tunnel the patient was referred with persisting symptoms of median and ulnar nerve compression and a prominent mass of her left palm and thenar eminence. Clinical examination, magnetic resonance imaging, nerve conduction study and biopsy, revealed a giant lipoma in the deep palmar space (8.0 × 4.0 × 3.75 cm, which was also infiltrating the carpal tunnel. She had already undergone two operations for carpal tunnel syndrome with no relief of her symptoms and she also ended up with a severed flexor pollicis longus tendon. Definitive treatment was performed by marginal resection of the lipoma and restoration of the flexor pollicis longus with an intercalated graft harvested from the palmaris longus. Thirty months after surgery the patient had a fully functional hand without any neurological deficit. Conclusion Not all lipomas of the wrist and hand are diagnosed. Our report tries to emphasize the hidden danger of lipomas in cases with carpal tunnel symptoms. The need for a high index of suspicion in conjunction with good clinical evaluation and the use of appropriate investigative studies is mandatory in order to avoid unnecessary operations and complications. Marginal excision of these tumors is restorative.

Progression and variation of fatty infiltration of the thigh muscles in Duchenne muscular dystrophy, a muscle magnetic resonance imaging study.

Science.gov (United States)

Li, Wenzhu; Zheng, Yiming; Zhang, Wei; Wang, Zhaoxia; Xiao, Jiangxi; Yuan, Yun

2015-05-01

The purpose of this study was to assess the progression and variation of fatty infiltration of the thigh muscles of Duchenne muscular dystrophy patients. Muscle magnetic resonance imaging was used to measure the degree of fatty infiltration of the thigh muscles of 171 boys with Duchenne muscular dystrophy (mean age, 6.09 ± 2.30 years). Fatty infiltration was assigned using a modified Mercuri's scale 0-5 (normal-severe). The gluteus maximus and adductor magnus were affected in patients less than two years old, followed by the biceps femoris. Quadriceps and semimembranosus were first affected at the age of five to six years; the sartorius, gracilis and adductor longus remained apparently unaffected until seven years of age. Fatty infiltration of all the thigh muscles developed rapidly after seven years of age. The standard deviation of the fatty infiltration scores ranged from 2.41 to 4.87 before five years old, and from 6.84 to 11.66 between six and ten years old. This study provides evidence of highly variable degrees of fatty infiltration in children of different ages with Duchenne muscular dystrophy, and indicates that fatty infiltration progresses more quickly after seven years of age. These findings may be beneficial for the selection of therapeutic regimens and the analysis of future clinical trials. Copyright © 2015 Elsevier B.V. All rights reserved.

Flexor hallucis longus tendon rupture in RA-patients is associated with MTP 1 damage and pes planus

NARCIS (Netherlands)

Baan, H.; Baan, Henriette; Drossaers-Bakker, K.W.; Dubbeldam, Rosemary; Dubbeldam, Rosemary; Buurke, Jaap J.; Nene, A.V.; van de Laar, Mart A F J

2007-01-01

Background: To assess the prevalence of and relation between rupture or tenosynovitis of the Flexor Hallucis Longus (FHL) tendon and range of motion, deformities and joint damage of the forefoot in RA patients with foot complaints. Methods: Thirty RA patients with painful feet were analysed, their

The expression of NFATc1 in adult rat skeletal muscle fibres.

Science.gov (United States)

Mutungi, Gabriel

2008-03-01

Although numerous studies have recently implicated the calcineurin-nuclear factor of activated T-cells (Cn-NFAT) signalling pathway in the regulation of activity-dependent fibre type switching in adult mammalian skeletal muscles, little is known about the endogenous expression of NFAT proteins in the various fibre types present in these muscles. In this study, the immunolocalization of NFATc1 (also known as NFATc or NFAT2) in the extensor digitorum longus (EDL; a mainly fast-twitch muscle) and the soleus (a predominantly slow-twitch muscle) muscles of adult ( approximately 90-day-old) Wistar rats was investigated. The results show that NFATc1 is expressed only in oxidative fibres (i.e. type I and type IIA fibres) that stain intensely for succinate dehydrogenase activity irrespective of whether they are from the fast- or slow-twitch muscle. Thus, 99 +/- 4% (n = 7 rats) of the muscle fibres in the soleus and 42 +/- 2% (n = 7 rats) of those in the EDL expressed NFATc1. In the soleus muscle fibres, NFATc1 was localized mainly in the fibre nuclei, whereas in the EDL fibres it was localized in both the cytoplasm and the nuclei. However, no difference in its localization was observed between type I and type IIA fibres in both muscles. Western blot experiments showed that the soleus expressed more NFATc1 proteins than the EDL. From these results, we suggest that NFATc1 controls the number and distribution of both type I and type IIA fibres, as well as the oxidative capacity of adult mammalian skeletal muscles.

Fetal development of deep back muscles in the human thoracic region with a focus on transversospinalis muscles and the medial branch of the spinal nerve posterior ramus

Science.gov (United States)

Sato, Tatsuo; Koizumi, Masahiro; Kim, Ji Hyun; Kim, Jeong Hyun; Wang, Bao Jian; Murakami, Gen; Cho, Baik Hwan

2011-01-01

Fetal development of human deep back muscles has not yet been fully described, possibly because of the difficulty in identifying muscle bundle directions in horizontal sections. Here, we prepared near-frontal sections along the thoracic back skin (eight fetuses) as well as horizontal sections (six fetuses) from 14 mid-term fetuses at 9–15 weeks of gestation. In the deep side of the trapezius and rhomboideus muscles, the CD34-positive thoracolumbar fascia was evident even at 9 weeks. Desmin-reactivity was strong and homogeneous in the superficial muscle fibers in contrast to the spotty expression in the deep fibers. Thus, in back muscles, formation of the myotendinous junction may start from the superficial muscles and advance to the deep muscles. The fact that developing intramuscular tendons were desmin-negative suggested little possibility of a secondary change from the muscle fibers to tendons. We found no prospective spinalis muscle or its tendinous connections with other muscles. Instead, abundant CD68-positive macrophages along the spinous process at 15 weeks suggested a change in muscle attachment, an event that may result in a later formation of the spinalis muscle. S100-positive intramuscular nerves exhibited downward courses from the multifidus longus muscle in the original segment to the rotatores brevis muscles in the inferiorly adjacent level. The medial cutaneous nerve had already reached the thoracolumbar fascia at 9 weeks, but by 15 weeks the nerve could not penetrate the trapezius muscle. Finally, we propose a folded myotomal model of the primitive transversospinalis muscle that seems to explain a fact that the roofing tile-like configuration of nerve twigs in the semispinalis muscle is reversed in the multifidus and rotatores muscles. PMID:21954879

Dorsal capsulodesis associated with arthoscopy-assisted scapholunate ligament reconstruction using a palmaris longus tendon graft

Directory of Open Access Journals (Sweden)

Victor Bignatto Carvalho

Full Text Available ABSTRACT OBJECTIVES: To measure the quality of life, the time to work return, and clinical, functional, and radiographic parameters of patients treated with dorsal capsulodesis associated with scapholunate (SL reconstruction, assisted by arthroscopy. METHODS: From January 2015 to September 2016, 14 adult patients with SL dissociation underwent surgical treatment with the SL reconstruction procedure assisted by arthroscopy, using the new technique proposed in this study. All patients were assessed by the occupational therapy department at regular intervals after surgery and performed the same sequence of rehabilitation. The parameters analyzed were: range of motion (ROM, Disability of the Arm, Shoulder, and Hand (DASH, visual analog scale (VAS, and radiographic analysis to visualize the pre- and postoperative SL gap and the pre- and postoperative dorsal intercalated segment instability (DISI deformity the. The complications and the time to return to work activities were described. RESULTS: The follow-up time was 12 months (3-17. The ROM averaged 321° (96.9% of the normal side. VAS was 1.79/10 (1-6. DASH was 6.50/100 (1-30. The time to work return work was 4.42 months (2-17. As for complications, one patient developed SLAC, and underwent four-corner fusion one year after ligament reconstruction. Currently, he has experienced pain relief, with a functional range of motion of the wrist, and has not yet returned to professional activities. The preoperative SL gap was 4.29 mm (2-7; in the postoperative period, it was 1.79 mm (1-4. The DISI deformity was present in ten patients with SL angle > 70° (preoperative and it was corrected after surgery, in all patients. SLAC stage I was identified in a patient. Arthroscopy was performed in all cases. The SL instability was classified as Geissler grade III in four cases and as grade IV in ten cases. CONCLUSION: The new approach (dorsal capsulodesis associated with SL reconstruction, assisted by arthroscopy presented in this study is safe and effective in the treatment of SL dissociation, since it offers satisfactory clinical, radiographic and functional results, showing low rates of complications. For patients, it allows the return to their social and professional activities, and increases their life quality.

Morphological and functional analyses of skeletal muscles from an immunodeficient animal model of limb-girdle muscular dystrophy type 2E.

Science.gov (United States)

Giovannelli, Gaia; Giacomazzi, Giorgia; Grosemans, Hanne; Sampaolesi, Maurilio

2018-02-24

Limb-girdle muscular dystrophy type 2E (LGMD2E) is caused by mutations in the β-sarcoglycan gene, which is expressed in skeletal, cardiac, and smooth muscles. β-Sarcoglycan-deficient (Sgcb-null) mice develop severe muscular dystrophy and cardiomyopathy with focal areas of necrosis. In this study we performed morphological (histological and cellular characterization) and functional (isometric tetanic force and fatigue) analyses in dystrophic mice. Comparison studies were carried out in 1-month-old (clinical onset of the disease) and 7-month-old control mice (C57Bl/6J, Rag2/γc-null) and immunocompetent and immunodeficient dystrophic mice (Sgcb-null and Sgcb/Rag2/γc-null, respectively). We found that the lack of an immunological system resulted in an increase of calcification in striated muscles without impairing extensor digitorum longus muscle performance. Sgcb/Rag2/γc-null muscles showed a significant reduction of alkaline phosphate-positive mesoangioblasts. The immunological system counteracts skeletal muscle degeneration in the murine model of LGMD2E. Muscle Nerve, 2018. © 2018 The Authors. Muscle & Nerve Published by Wiley Periodicals, Inc.

Muscle Activation During Landing Before and After Fatigue in Individuals With or Without Chronic Ankle Instability

Science.gov (United States)

Webster, Kathryn A.; Pietrosimone, Brian G.; Gribble, Phillip A.

2016-01-01

Context: Ankle instability is a common condition in physically active individuals. It often occurs during a jump landing or lateral motion, particularly when participants are fatigued. Objective: To compare muscle activation during a lateral hop prefatigue and postfatigue in individuals with or without chronic ankle instability (CAI). Design: Cross-sectional study. Setting: Sports medicine research laboratory. Patients or Other Participants: A total of 32 physically active participants volunteered for the study. Sixteen participants with CAI (8 men, 8 women; age = 20.50 ± 2.00 years, height = 172.25 ± 10.87 cm, mass = 69.13 ± 13.31 kg) were matched with 16 control participants without CAI (8 men, 8 women; age = 22.00 ± 3.30 years, height = 170.50 ± 9.94 cm, mass = 69.63 ± 14.82 kg) by age, height, mass, sex, and affected side. Intervention(s): Electromyography of the tibialis anterior, peroneus longus, gluteus medius, and gluteus maximus was measured before and after a functional fatigue protocol. Main Outcome Measure(s): Activation of 4 lower extremity muscles was measured 200 milliseconds before and after landing from a lateral hop. Results: We observed no interactions. The group main effects for the peroneus longus demonstrated higher muscle activation in the CAI group (52.89% ± 11.36%) than in the control group (41.12% ± 11.36%) just before landing the lateral hop (F1,30 = 8.58, P = .01), with a strong effect size (d = 1.01). The gluteus maximus also demonstrated higher muscle activation in the CAI group (45.55% ± 12.08%) than in the control group (36.81% ± 12.08%) just before landing the lateral hop (F1,30 = 4.19, P = .049), with a moderate effect size (d = 0.71). We observed a main effect for fatigue for the tibialis anterior, with postfatigue activation higher than prefatigue activation (F1,30 = 7.45, P = .01). No differences were present between groups for the gluteus medius. Conclusions: Our results support the presence of a centralized feed

Use of muscle functional magnetic resonance imaging to compare cervical flexor activity between patients with whiplash-associated disorders and people who are healthy.

Science.gov (United States)

Cagnie, Barbara; Dolphens, Mieke; Peeters, Ian; Achten, Eric; Cambier, Dirk; Danneels, Lieven

2010-08-01

Chronic whiplash-associated disorders (WAD) have been shown to be associated with motor dysfunction. Increased electromyographic (EMG) activity in neck and shoulder girdle muscles has been demonstrated during different tasks in participants with persistent WAD. Muscle functional magnetic resonance imaging (mfMRI) is an innovative technique to evaluate muscle activity and differential recruitment of deep and superficial muscles following exercise. The purpose of this study was to compare the recruitment pattern of deep and superficial neck flexors between patients with WAD and controls using mfMRI. A cross-sectional design was used. The study was conducted in a physical and rehabilitation medicine department. The participants were 19 controls who were healthy (10 men, 9 women; mean [+/-SD] age=22.2+/-0.6 years) and 16 patients with WAD (5 men, 11 women; mean [+/-SD] age=32.9+/-12.7 years). The T2 values were calculated for the longus colli (Lco), longus capitis (Lca), and sternocleidomastoid (SCM) muscles at rest and following cranio-cervical flexion (CCF). In the overall statistical model for T2 shift, there was a significant main effect for muscle (F=3.906, P=.033) but not for group (F=2.855, P=.101). The muscle x group interaction effect was significant (F=3.618, P=.041). Although not significant, there was a strong trend for lesser Lco (P=.061) and Lca (P=.060) activity for the WAD group compared with the control group. Although the SCM showed higher T2 shifts, this difference was not significant (P=.291). Although mfMRI is an innovative and useful technique for the evaluation of deep cervical muscles, consideration is required, as this method encompasses a postexercise evaluation and is limited to resistance types of exercises. Muscle functional magnetic resonance imaging demonstrated a difference in muscle recruitment between the Lco, Lca, and SCM during CCF in the control group, but failed to demonstrate a changed activity pattern in the WAD group compared

Myosin phosphorylation improves contractile economy of mouse fast skeletal muscle during staircase potentiation.

Science.gov (United States)

Bunda, Jordan; Gittings, William; Vandenboom, Rene

2018-01-30

Phosphorylation of the myosin regulatory light chain (RLC) by skeletal myosin light chain kinase (skMLCK) potentiates rodent fast twitch muscle but is an ATP-requiring process. Our objective was to investigate the effect of skMLCK-catalyzed RLC phosphorylation on the energetic cost of contraction and the contractile economy (ratio of mechanical output to metabolic input) of mouse fast twitch muscle in vitro (25°C). To this end, extensor digitorum longus (EDL) muscles from wild-type (WT) and from skMLCK-devoid (skMLCK -/- ) mice were subjected to repetitive low-frequency stimulation (10 Hz for 15 s) to produce staircase potentiation of isometric twitch force, after which muscles were quick frozen for determination of high-energy phosphate consumption (HEPC). During stimulation, WT muscles displayed significant potentiation of isometric twitch force while skMLCK -/- muscles did not (i.e. 23% versus 5% change, respectively). Consistent with this, RLC phosphorylation was increased ∼3.5-fold from the unstimulated control value in WT but not in skMLCK -/- muscles. Despite these differences, the HEPC of WT muscles was not greater than that of skMLCK -/- muscles. As a result of the increased contractile output relative to HEPC, the calculated contractile economy of WT muscles was greater than that of skMLCK -/- muscles. Thus, our results suggest that skMLCK-catalyzed phosphorylation of the myosin RLC increases the contractile economy of WT mouse EDL muscle compared with skMLCK -/- muscles without RLC phosphorylation. © 2018. Published by The Company of Biologists Ltd.

Changes in the cholinergic system of rat sciatic nerve and skeletal muscle following suspension induced disuse

Science.gov (United States)

Gupta, R. C.; Misulis, K. E.; Dettbarn, W. D.

1984-01-01

Muscle disused induced changes in the cholinergic system of sciatic nerve, slow twitch soleus (SOL) and fast twitch extensor digitorum longus (EDL) muscle were studied in rats. Rats with hindlimbs suspended for 2 to 3 weeks showed marked elevation in the activity of choline acetyltransferase (ChAT) in sciatic nerve (38%), in SOL (108%) and in EDL (67%). Acetylcholinesterase (AChE) activity in SOL increased by 163% without changing the molecular forms pattern of 4S, 10S, 12S, and 16S. No significant changes in activity and molecular forms pattern of AChE were seen in EDL or in AChE activity of sciatic nerve. Nicotinic receptor binding of 3H-acetylcholine was increased in both muscles. When measured after 3 weeks of hindlimb suspension the normal distribution of type 1 fibers in SOL was reduced and a corresponding increase in type IIa and IIb fibers is seen. In EDL no significant change in fiber proportion is observed. Muscle activity, such as loadbearing, appears to have a greater controlling influence on the characteristics of the slow twitch SOL muscle than upon the fast twitch EDL muscle.

Contraction-induced skeletal muscle FAT/CD36 trafficking and FA uptake is AMPK independent

Science.gov (United States)

Jeppesen, J.; Albers, P. H.; Rose, A. J.; Birk, J. B.; Schjerling, P.; Dzamko, N.; Steinberg, G. R.; Kiens, B.

2011-01-01

The aim of this study was to investigate the molecular mechanisms regulating FA translocase CD36 (FAT/CD36) translocation and FA uptake in skeletal muscle during contractions. In one model, wild-type (WT) and AMP-dependent protein kinase kinase dead (AMPK KD) mice were exercised or extensor digitorum longus (EDL) and soleus (SOL) muscles were contracted, ex vivo. In separate studies, FAT/CD36 translocation and FA uptake in response to muscle contractions were investigated in the perfused rat hindlimb. Exercise induced a similar increase in skeletal muscle cell surface membrane FAT/CD36 content in WT (+34%) and AMPK KD (+37%) mice. In contrast, 5-aminoimidazole-4-carboxamide ribonucleoside only induced an increase in cell surface FAT/CD36 content in WT (+29%) mice. Furthermore, in the perfused rat hindlimb, muscle contraction induced a rapid (1 min, +15%) and sustained (10 min, +24%) FAT/CD36 relocation to cell surface membranes. The increase in cell surface FAT/CD36 protein content with muscle contractions was associated with increased FA uptake, both in EDL and SOL muscle from WT and AMPK KD mice and in the perfused rat hindlimb. This suggests that AMPK is not essential in regulation of FAT/CD36 translocation and FA uptake in skeletal muscle during contractions. However, AMPK could be important in regulation of FAT/CD36 distribution in other physiological situations. PMID:21297178

Metabolic characteristics of skeletal muscle from lean and obese Zucker rats

International Nuclear Information System (INIS)

Campion, D.R.; Shapira, J.F.; Allen, C.E.; Hausman, G.J.; Martin, R.J.

1987-01-01

The purpose of this study was to determine if the metabolic response to obesity and to pair feeding of obese Zucker rats to lean Zucker rats was similar across skeletal muscles. Oxidation of glucose, palmitate and isoleucine was studied in muscle strips in vitro using appropriate 14- carbon substrates as tracers. The plantaris muscle was subjected to histochemical analyses using an alkaline actomyosin ATPase, NADH-tetrazolium reductase and an oil red 0 stain. Soleus muscles from both ad libitum and pair fed obese rats oxidized less glucose to CO 2 , but released similar amounts of lactate when compared to the soleus muscles of lean rats. Oxidation of glucose was similar in the extensor digitorum longus (EDL) muscle of ad libitum fed obese rats, but lower when pair fed to the intake of lean rats. No differences were apparent in palmitate oxidation to CO 2 or in incorporation into lipid, except in the EDL muscle of pair-fed obese rats which exhibited a higher rate for palmitate metabolism when compared with lean rats. Isoleucine oxidation to CO 2 was higher in the EDL and plantaris muscles, but similar in the soleus muscle of ad libitum-fed obese rats when compared with lean rats. The magnitude of the difference in isoleucine oxidation was similar when the obese rats were pair fed. No differences in the percentage of plantaris muscle fibers sensitive to alkaline ATPase staining were observed. The plantaris muscle of obese rats, contained a higher proportion of oxidative fibers. These results indicate the great risk in generalizing about metabolic activity of the whole skeletal muscle mass based on observations made on one, or even two, distinct muscles in this animal model. Also, pair feeding of obese to lean Zucker rats did not result in uniform change sin metabolism between muscles of the obese rats

Peroneal perforator-based peroneus longus tendon and sural neurofasciocutaneous composite flap transfer for a large soft-tissue defect of the forearm: A case report.

Science.gov (United States)

Hayashida, Kenji; Saijo, Hiroto; Fujioka, Masaki

2018-01-01

We describe the use of a composite flap composed of a sural neurofasciocutaneous flap and a vascularized peroneus longus tendon for the reconstruction of severe composite forearm tissue defects in a patient. A 43-year-old man had his left arm caught in a conveyor belt resulting in a large soft-tissue defect of 18 × 11 cm over the dorsum forearm. The extensor carpi radialis, superficial radial nerve, and radial artery were severely damaged. A free neurofasciocutaneous composite flap measuring 16 × 11 cm was outlined on the patient's left lower leg to allow simultaneous skin, tendon, nerve, and artery reconstruction. The flap, which included the peroneus longus tendon, was elevated on the subfascial plane. After the flap was transferred to the recipient site, the peroneal artery was anastomosed to the radial artery in a flow-through manner. The vascularized tendon graft with 15 cm in length was used to reconstruct the extensor carpi radialis longus tendon defect using an interlacing suture technique. As the skin paddle of the sural neurofasciocutaneous flap and the vascularized peroneus longus tendon graft were linked by the perforator and minimal fascial tissue, the skin paddle was able to rotate and slide with comparative ease. The flap survived completely without any complications. The length of follow-up was 12 months and was uneventful. Range of motion of his left wrist joint was slightly limited to 75 degrees. This novel composite flap may be useful for reconstructing long tendon defects associated with extensive forearm soft tissue defects. © 2016 Wiley Periodicals, Inc.

Pulsed ultrasound therapy accelerates the recovery of skeletal muscle damage induced by Bothrops jararacussu venom

Directory of Open Access Journals (Sweden)

J. Saturnino-Oliveira

2012-06-01

Full Text Available We studied the effect of pulsed ultrasound therapy (UST and antibothropic polyvalent antivenom (PAV on the regeneration of mouse extensor digitorum longus muscle following damage by Bothrops jararacussu venom. Animals (Swiss male and female mice weighing 25.0 ± 5.0 g; 5 animals per group received a perimuscular injection of venom (1 mg/kg and treatment with UST was started 1 h later (1 min/day, 3 MHz, 0.3 W/cm², pulsed mode. Three and 28 days after injection, muscles were dissected and processed for light microscopy. The venom caused complete degeneration of muscle fibers. UST alone and combined with PAV (1.0 mL/kg partially protected these fibers, whereas muscles receiving no treatment showed disorganized fascicules and fibers with reduced diameter. Treatment with UST and PAV decreased the effects of the venom on creatine kinase content and motor activity (approximately 75 and 48%, respectively. Sonication of the venom solution immediately before application decreased the in vivo and ex vivo myotoxic activities (approximately 60 and 50%, respectively. The present data show that UST counteracts some effects of B. jararacussu venom, causing structural and functional improvement of the regenerated muscle after venom injury.

Passive stiffness of rat skeletal muscle undernourished during fetal development

Directory of Open Access Journals (Sweden)

Ana Elisa Toscano

2010-01-01

Full Text Available OBJECTIVES: The aim of the study was to investigate the effect of fetal undernutrition on the passive mechanical properties of skeletal muscle of weaned and young adult rats. INTRODUCTION: A poor nutrition supply during fetal development affects physiological functions of the fetus. From a mechanical point of view, skeletal muscle can be also characterized by its resistance to passive stretch. METHODS: Male Wistar rats were divided into two groups according to their mother's diet during pregnancy: a control group (mothers fed a 17% protein diet and an isocaloric low-protein group (mothers fed a 7.8% protein diet. At birth, all mothers received a standardized meal ad libitum. At the age of 25 and 90 days, the soleus muscle and extensor digitorum longus (EDL muscles were removed in order to test the passive mechanical properties. A first mechanical test consisted of an incremental stepwise extension test using fast velocity stretching (500 mm/s enabling us to measure, for each extension stepwise, the dynamic stress (σd and the steady stress (σs. A second test consisted of a slow velocity stretch in order to calculate normalized stiffness and tangent modulus from the stress-strain relationship. RESULTS: The results for the mechanical properties showed an important increase in passive stiffness in both the soleus and EDL muscles in weaned rat. In contrast, no modification was observed in young adult rats. CONCLUSIONS: The increase in passive stiffness in skeletal muscle of weaned rat submitted to intrauterine undernutrition it is most likely due to changes in muscle passive stiffness.

Knockout of the predominant conventional PKC isoform, PKCalpha, in mouse skeletal muscle does not affect contraction-stimulated glucose uptake

DEFF Research Database (Denmark)

Jensen, Thomas E; Maarbjerg, Stine J; Rose, Adam J

2009-01-01

Conventional (c) protein kinase C (PKC) activity has been shown to increase with skeletal muscle contraction, and numerous studies using primarily pharmacological inhibitors have implicated cPKCs in contraction-stimulated glucose uptake. Here, to confirm that cPKC activity is required for contrac...... working on other parts of contraction-induced signaling or the remaining cPKC isoforms are sufficient for stimulating glucose uptake during contractions.......Conventional (c) protein kinase C (PKC) activity has been shown to increase with skeletal muscle contraction, and numerous studies using primarily pharmacological inhibitors have implicated cPKCs in contraction-stimulated glucose uptake. Here, to confirm that cPKC activity is required...... for contraction-stimulated glucose uptake in mouse muscles, contraction-stimulated glucose uptake ex vivo was first evaluated in the presence of three commonly used cPKC inhibitors (calphostin C, Gö-6976, and Gö-6983) in incubated mouse soleus and extensor digitorum longus (EDL) muscles. All potently inhibited...

Periodic modulation of motor-unit activity in extrinsic hand muscles during multidigit grasping.

Science.gov (United States)

Johnston, Jamie A; Winges, Sara A; Santello, Marco

2005-07-01

We recently examined the extent to which motor units of digit flexor muscles receive common input during multidigit grasping. This task elicited moderate to strong motor-unit synchrony (common input strength, CIS) across muscles (flexor digitorum profundus, FDP, and flexor pollicis longus, FPL) and across FDP muscle compartments, although the strength of this common input was not uniform across digit pairs. To further characterize the neural mechanisms underlying the control of multidigit grasping, we analyzed the relationship between firing of single motor units from these hand muscles in the frequency domain by computing coherence. We report three primary findings. First, in contrast to what has been reported in intrinsic hand muscles, motor units belonging to different muscles and muscle compartments of extrinsic digit flexors exhibited significant coherence in the 0- to 5- and 5- to 10-Hz frequency ranges and much weaker coherence in the higher 10-20 Hz range (maximum 0.0025 and 0.0008, respectively, pooled across all FDP compartment pairs). Second, the strength and incidence of coherence differed considerably across digit pairs. Third, contrary to what has been reported in the literature, across-muscle coherence can be stronger and more prevalent than within-muscle coherence, as FPL-FDP2 (thumb-index digit pair) exhibited the strongest and most prevalent coherence in our data (0.010 and 43% at 3 Hz, respectively). The heterogeneous organization of common input to these muscles and muscle compartments is discussed in relation to the functional role of individual digit pairs in the coordination of multiple digit forces in grasping.

Expression of interleukin-15 and inflammatory cytokines in skeletal muscles of STZ-induced diabetic rats: effect of resistance exercise training.

Science.gov (United States)

Molanouri Shamsi, M; Hassan, Z H; Gharakhanlou, R; Quinn, L S; Azadmanesh, K; Baghersad, L; Isanejad, A; Mahdavi, M

2014-05-01

Skeletal muscle atrophy is associated with type-1 diabetes. Skeletal muscle is the source of pro- and anti-inflammatory cytokines that can mediate muscle hypertrophy and atrophy, while resistance exercise can modulate both muscle mass and muscle cytokine expression. This study determined the effects of a 5-week resistance exercise training regimen on the expression of muscle cytokines in healthy and streptozotocin-induced diabetic rats, with special emphasis on interleukin-15 (IL-15), a muscle-derived cytokine proposed to be involved in muscle hypertrophy or responses to stress. Induction of diabetes reduced muscle weight in both the fast flexor hallucis longus (FHL) and slow soleus muscles, while resistance training preserved FHL muscle weight in diabetic rats. IL-15 protein content was increased by training in both FHL and soleus muscles, as well as serum, in normal and diabetic rats. With regard to proinflammatory cytokines, muscle IL-6 levels were increased in diabetic rats, while training decreased muscle IL-6 levels in diabetic rats; training had no effect on FHL muscle IL-6 levels in healthy rats. Also, tumor necrosis factor-alpha (TNF-α) and IL-1β levels were increased by diabetes, but not changed by training. In conclusion, we found that in diabetic rats, resistance training increased muscle and serum IL-15 levels, decreased muscle IL-6 levels, and preserved FHL muscle mass.

Prevalence of and referred pain from myofascial trigger points in the forearm muscles in patients with lateral epicondylalgia.

Science.gov (United States)

Fernández-Carnero, Josué; Fernández-de-Las-Peñas, César; de la Llave-Rincón, Ana Isabel; Ge, Hong-You; Arendt-Nielsen, Lars

2007-05-01

Referred pain and pain characteristics evoked from the extensor carpi radialis brevis, extensor carpi radialis longus, extensor digitorum communis, and brachioradialis muscles was investigated in 20 patients with lateral epicondylalgia (LE) and 20-matched controls. Both groups were examined for the presence of myofascial trigger points (TrPs) in a blinded fashion. The quality and location of the evoked referred pain, and the pressure pain threshold (PPT) at the lateral epicondyle on the right upper extremity (symptomatic side in patients, and dominant-side on controls) were recorded. Several lateral elbow pain parameters were also evaluated. Within the patient group, the elicited referred pain by manual exploration of 13 out of 20 (65%) extensor carpi radialis brevis muscles, 12/20 (70%) extensor carpi radialis longus muscles, 10/20 (50%) brachioradialis muscles, and 5/20 (25%) extensor digitorum communis muscles, shares similar pain patterns as their habitual lateral elbow and forearm pain. The mean number of muscles with TrPs for each patient was 2.9 [95% confidence interval (CI) 1,4] of which 2 (95% CI 1,3) were active, and 0.9 (95% CI 0,2) were latent TrPs. Control participants only had latent TrPs (mean: 0.4; 95% CI 0,2). TrP occurrence between the 2 groups was significantly different for active TrPs (P0.05). The referred pain pattern was larger in patients than in controls, with pain referral to the lateral epicondyle (proximally) and to the dorso-lateral aspect of the forearm in the patients, and confined to the dorso-lateral aspect of the forearm in the controls. Patients with LE showed a significant (Plateral epicondyle was negatively correlated with both the total number of TrPs (rs=-0.63; P=0.003) and the number of active TrPs (rs=-0.5; P=0.02): the greater the number of active TrPs, the lower the PPT at the lateral epicondyle. Our results suggest that in patients with LE, the evoked referred pain and its sensory characteristics shared similar patterns

Effects of elevated temperature on protein breakdown in muscles from septic rats

International Nuclear Information System (INIS)

Hall-Angeras, M.A.; Angeras, U.H.; Hasselgren, P.O.; Fischer, J.E.

1990-01-01

Elevated temperature has been proposed to contribute to accelerated muscle protein degradation during fever and sepsis. The present study examined the effect of increased temperature in vitro on protein turnover in skeletal muscles from septic and control rats. Sepsis was induced by cecal ligation and puncture (CLP); control rats were sham operated. After 16 h, the extensor digitorum longus (EDL) and soleus (SOL) muscles were incubated at 37 or 40 degrees C. Protein synthesis was determined by measuring incorporation of [14C]phenylalanine into protein. Total and myofibrillar protein breakdown was assessed from release of tyrosine and 3-methylhistidine (3-MH), respectively. Total protein breakdown was increased at 40 degrees C by 15% in EDL and by 29% in SOL from control rats, whereas 3-MH release was not affected. In muscles from septic rats, total and myofibrillar protein breakdown was increased by 22 and 30%, respectively, at 40 degrees C in EDL but was not altered in SOL. Protein synthesis was unaffected by high temperature both in septic and nonseptic muscles. The present results suggest that high temperature is not the primary mechanism of increased muscle protein breakdown in sepsis because the typical response to sepsis, i.e., a predominant increase in myofibrillar protein breakdown, was not induced by elevated temperature in normal muscle. It is possible, however, that increased temperature may potentiate protein breakdown that is already stimulated by sepsis because elevated temperature increased both total and myofibrillar protein breakdown in EDL from septic rats

Induction of amino acid transporters expression by endurance exercise in rat skeletal muscle

International Nuclear Information System (INIS)

Murakami, Taro; Yoshinaga, Mariko

2013-01-01

Highlights: •Regulation of amino acid transporter expression in working muscle remains unclear. •Expression of amino acid transporters for leucine were induced by a bout of exercise. •Requirement of leucine in muscle cells might regulate expression of its transporters. •This information is beneficial for understanding the muscle remodeling by exercise. -- Abstract: We here investigated whether an acute bout of endurance exercise would induce the expression of amino acid transporters that regulate leucine transport across plasma and lysosomal membranes in rat skeletal muscle. Rats ran on a motor-driven treadmill at a speed of 28 m/min for 90 min. Immediately after the exercise, we observed that expression of mRNAs encoding L-type amino acid transporter 1 (LAT1) and CD98 was induced in the gastrocnemius, soleus, and extensor digitorum longus (EDL) muscles. Sodium-coupled neutral amino acid transporter 2 (SNAT2) mRNA was also induced by the exercise in those three muscles. Expression of proton-assisted amino acid transporter 1 (PAT1) mRNA was slightly but not significantly induced by a single bout of exercise in soleus and EDL muscles. Exercise-induced mRNA expression of these amino acid transporters appeared to be attenuated by repeated bouts of the exercise. These results suggested that the expression of amino acid transporters for leucine may be induced in response to an increase in the requirement for this amino acid in the cells of working skeletal muscles

HDAC4-Myogenin Axis As an Important Marker of HD-Related Skeletal Muscle Atrophy

Science.gov (United States)

Smeets, Cleo J. L. M.; Franklin, Sophie A.; Bondulich, Marie K.; Jolinon, Nelly; Muller, Thomas; Ahmed, Mhoriam; Dick, James R. T.; Piotrowska, Izabela; Greensmith, Linda; Smolenski, Ryszard T.; Bates, Gillian P.

2015-01-01

Skeletal muscle remodelling and contractile dysfunction occur through both acute and chronic disease processes. These include the accumulation of insoluble aggregates of misfolded amyloid proteins that is a pathological feature of Huntington’s disease (HD). While HD has been described primarily as a neurological disease, HD patients’ exhibit pronounced skeletal muscle atrophy. Given that huntingtin is a ubiquitously expressed protein, skeletal muscle fibres may be at risk of a cell autonomous HD-related dysfunction. However the mechanism leading to skeletal muscle abnormalities in the clinical and pre-clinical HD settings remains unknown. To unravel this mechanism, we employed the R6/2 transgenic and HdhQ150 knock-in mouse models of HD. We found that symptomatic animals developed a progressive impairment of the contractile characteristics of the hind limb muscles tibialis anterior (TA) and extensor digitorum longus (EDL), accompanied by a significant loss of motor units in the EDL. In symptomatic animals, these pronounced functional changes were accompanied by an aberrant deregulation of contractile protein transcripts and their up-stream transcriptional regulators. In addition, HD mouse models develop a significant reduction in muscle force, possibly as a result of a deterioration in energy metabolism and decreased oxidation that is accompanied by the re-expression of the HDAC4-DACH2-myogenin axis. These results show that muscle dysfunction is a key pathological feature of HD. PMID:25748626

Denervation in murine fast-twitch muscle: short-term physiological changes and temporal expression profiling.

Science.gov (United States)

Raffaello, Anna; Laveder, Paolo; Romualdi, Chiara; Bean, Camilla; Toniolo, Luana; Germinario, Elena; Megighian, Aram; Danieli-Betto, Daniela; Reggiani, Carlo; Lanfranchi, Gerolamo

2006-03-13

Denervation deeply affects muscle structure and function, the alterations being different in slow and fast muscles. Because the effects of denervation on fast muscles are still controversial, and high-throughput studies on gene expression in denervated muscles are lacking, we studied gene expression during atrophy progression following denervation in mouse tibialis anterior (TA). The sciatic nerve was cut close to trochanter in adult CD1 mice. One, three, seven, and fourteen days after denervation, animals were killed and TA muscles were dissected out and utilized for physiological experiments and gene expression studies. Target cDNAs from TA muscles were hybridized on a dedicated cDNA microarray of muscle genes. Seventy-one genes were found differentially expressed. Microarray results were validated, and the expression of relevant genes not probed on our array was monitored by real-time quantitative PCR (RQ-PCR). Nuclear- and mitochondrial-encoded genes implicated in energy metabolism were consistently downregulated. Among genes implicated in muscle contraction (myofibrillar and sarcoplasmic reticulum), genes typical of fast fibers were downregulated, whereas those typical of slow fibers were upregulated. Electrophoresis and Western blot showed less pronounced changes in myofibrillar protein expression, partially confirming changes in gene expression. Isometric tension of skinned fibers was little affected by denervation, whereas calcium sensitivity decreased. Functional studies in mouse extensor digitorum longus muscle showed prolongation in twitch time parameters and shift to the left in force-frequency curves after denervation. We conclude that, if studied at the mRNA level, fast muscles appear not less responsive than slow muscles to the interruption of neural stimulation.

Resistance to rocuronium of rat diaphragm as compared with limb muscles.

Science.gov (United States)

Huang, Lina; Yang, Meirong; Chen, Lianhua; Li, Shitong

2014-12-01

Skeletal muscles are composed of different muscle fiber types. We investigated the different potency to rocuronium among diaphragm (DIA), extensor digitorum longus (EDL), and soleus (SOL) in vitro as well as to investigate the differences of acetylcholine receptors (AChRs) among these three typical kinds of muscles. The isolated left hemidiaphragm nerve-muscle preparations, the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations were established to evaluate the potency to rocuronium. Concentration-response curves were constructed and the values of IC50 were obtained. The density of AChRs at the end plate and the number of AChRs per unit fiber cross fiber area (CSA), AChR affinity for muscle relaxants were evaluated. The concentration-twitch tension curves of rocuronium were significantly different. The curves demonstrated a shift to the right of the DIA compared with the EDL and SOL (P  0.05). IC50 was significantly largest in DIA, second largest in SOL, and smallest in EDL (P rocuronium of DIA compared with EDL and SOL was verified. The DIA was characterized by the largest number of AChRs per unit fiber CSA and the lowest affinity of the AChRs. Although compared with SOL, EDL was proved to have larger number of AChRs per unit fiber CSA and the lower affinity of the AChRs. These findings may be the mechanisms of different potency to rocuronium in DIA, EDL, and SOL. The results of the study could help to explain the relationship between different composition of muscle fibers and the potency to muscle relaxants. Extra caution should be taken in clinical practice when monitoring muscle relaxation in anesthetic management using different muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

The effect of hip abduction on the EMG activity of vastus medialis obliquus, vastus lateralis longus and vastus lateralis obliquus in healthy subjects

Directory of Open Access Journals (Sweden)

Arakaki Juliano

2006-07-01

Full Text Available Abstract Study design Controlled laboratory study. Objectives The purposes of this paper were to investigate (d whether vastus medialis obliquus (VMO, vastus lateralis longus (VLL and vastus lateralis obliquus (VLO EMG activity can be influenced by hip abduction performed by healthy subjects. Background Some clinicians contraindicate hip abduction for patellofemoral patients (with based on the premise that hip abduction could facilitate the VLL muscle activation leading to a VLL and VMO imbalance Methods and measures Twenty-one clinically healthy subjects were involved in the study, 10 women and 11 men (aged X = 23.3 ± 2.9. The EMG signals were collected using a computerized EMG VIKING II, with 8 channels and three pairs of surface electrodes. EMG activity was obtained from MVIC knee extension at 90° of flexion in a seated position and MVIC hip abduction at 0° and 30° with patients in side-lying position with the knee in full extension. The data were normalized in the MVIC knee extension at 50° of flexion in a seated position, and were submitted to ANOVA test with subsequent application of the Bonferroni multiple comparisons analysis test. The level of significance was defined as p ≤ 0.05. Results The VLO muscle demonstrated a similar pattern to the VMO muscle showing higher EMG activity in MVIC knee extension at 90° of flexion compared with MVIC hip abduction at 0° and 30° of abduction for male (p Conclusion The results showed that no selective EMG activation was observed when comparison was made between the VMO, VLL and VLO muscles while performing MVIC hip abduction at 0° and 30° of abduction and MVIC knee extension at 90° of flexion in both male and female subjects. Our findings demonstrate that hip abduction do not facilitated VLL and VLO activity in relation to the VMO, however, this study included only healthy subjects performing maximum voluntary isometric contraction contractions, therefore much remains to be discovered by

Engraftment potential of dermal fibroblasts following in vivo myogenic conversion in immunocompetent dystrophic skeletal muscle

Directory of Open Access Journals (Sweden)

Lindsey A Muir

2014-01-01

Full Text Available Autologous dermal fibroblasts (dFbs are promising candidates for enhancing muscle regeneration in Duchenne muscular dystrophy (DMD due to their ease of isolation, immunological compatibility, and greater proliferative potential than DMD satellite cells. We previously showed that mouse fibroblasts, after MyoD-mediated myogenic reprogramming in vivo, engraft in skeletal muscle and supply dystrophin. Assessing the therapeutic utility of this system requires optimization of conversion and transplantation conditions and quantitation of engraftment so that these parameters can be correlated with possible functional improvements. Here, we derived dFbs from transgenic mice carrying mini-dystrophin, transduced them by lentivirus carrying tamoxifen-inducible MyoD, and characterized their myogenic and engraftment potential. After cell transplantation into the muscles of immunocompetent dystrophic mdx4cv mice, tamoxifen treatment drove myogenic conversion and fusion into myofibers that expressed high levels of mini-dystrophin. Injecting 50,000 cells/µl (1 × 106 total cells resulted in a peak of ∼600 mini-dystrophin positive myofibers in tibialis anterior muscle single cross-sections. However, extensor digitorum longus muscles with up to 30% regional engraftment showed no functional improvements; similar limitations were obtained with whole muscle mononuclear cells. Despite the current lack of physiological improvement, this study suggests a viable initial strategy for using a patient-accessible dermal cell population to enhance skeletal muscle regeneration in DMD.

Partial fast-to-slow conversion of regenerating rat fast-twitch muscle by chronic low-frequency stimulation.

Science.gov (United States)

Pette, Dirk; Sketelj, Janez; Skorjanc, Dejan; Leisner, Elmi; Traub, Irmtrud; Bajrović, Fajko

2002-01-01

Chronic low-frequency stimulation (CLFS) of rat fast-twitch muscles induces sequential transitions in myosin heavy chain (MHC) expression from MHCIIb --> MHCIId/x --> MHCIIa. However, the 'final' step of the fast-to-slow transition, i.e., the upregulation of MHCI, has been observed only after extremely long stimulation periods. Assuming that fibre degeneration/regeneration might be involved in the upregulation of slow myosin, we investigated the effects of CLFS on extensor digitorum longus (EDL) muscles regenerating after bupivacaine-induced fibre necrosis. Normal, non-regenerating muscles responded to both 30- and 60-day CLFS with fast MHC isoform transitions (MHCIIb --> MHCIId --> MHCIIa) and only slight increases in MHCI. CLFS of regenerating EDL muscles caused similar transitions among the fast isoforms but, in addition, caused significant increases in MHCI (to approximately 30% relative concentration). Stimulation periods of 30 and 60 days induced similar changes in the regenerating bupivacaine-treated muscles, indicating that the upregulation of slow myosin was restricted to regenerating fibres, but only during an early stage of regeneration. These results suggest that satellite cells and/or regenerating fast rat muscle fibres are capable of switching directly to a slow program under the influence of CLFS and, therefore, appear to be more malleable than adult fibres.

A comparative study of charge movement in rat and frog skeletal muscle fibres.

Science.gov (United States)

Hollingworth, S; Marshall, M W

1981-12-01

1. The middle of the fibre voltage--clamp technique (Adrian & Marshall, 1977), modified where necessary for electrically short muscle fibres, has been used to measure non-linear charge movements in mammalian fast twitch (rat extensor digitorum longus), mammalian slow twitch (rat soleus) and frog (sartorius) muscles. 2. The maximum amount of charge moved in mammalian fast twitch muscle at 2 degrees C in hypertonic solution, was 3--5 times greater than in slow twitch muscle. The voltage distribution of fast twitch charge was 10--15 mV more positive when compared to slow twitch. 3. In both mammalian muscle types hypertonic Ringer solution negatively shifted the voltage distribution of charge some 6 mV. The steepness of charge moved around mechanical threshold was unaffected by hypertonicity. 4. The amount of charge in frog sartorius fibres at 2 degrees C in hypertonic solution was about half of that in rat fast twitch muscle; the voltage distribution of the frog charge was similar to rat soleus muscle. 5. Warming between 2 and 15 degrees C had no effect on either the amount of steady-state distribution of charge in mammalian or frog muscles. 6. At 2 degrees C, the kinetics of charge movement in fast and slow twitch mammalian muscles were similar and 2--3 times faster than frog muscle at the same temperature. In fast and slow mammalian fibres at 2 degrees C similar times were taken to shift the same fractions of the total amount of charge. The Q10 of charge movement kinetics was between 1.2 and 2.0 in the three muscles studied.

Common input to motor units of intrinsic and extrinsic hand muscles during two-digit object hold.

Science.gov (United States)

Winges, Sara A; Kornatz, Kurt W; Santello, Marco

2008-03-01

Anatomical and physiological evidence suggests that common input to motor neurons of hand muscles is an important neural mechanism for hand control. To gain insight into the synaptic input underlying the coordination of hand muscles, significant effort has been devoted to describing the distribution of common input across motor units of extrinsic muscles. Much less is known, however, about the distribution of common input to motor units belonging to different intrinsic muscles and to intrinsic-extrinsic muscle pairs. To address this void in the literature, we quantified the incidence and strength of near-simultaneous discharges of motor units residing in either the same or different intrinsic hand muscles (m. first dorsal, FDI, and m. first palmar interosseus, FPI) during two-digit object hold. To extend the characterization of common input to pairs of extrinsic muscles (previous work) and pairs of intrinsic muscles (present work), we also recorded electromyographic (EMG) activity from an extrinsic thumb muscle (m. flexor pollicis longus, FPL). Motor-unit synchrony across FDI and FPI was weak (common input strength, CIS, mean +/- SE: 0.17 +/- 0.02). Similarly, motor units from extrinsic-intrinsic muscle pairs were characterized by weak synchrony (FPL-FDI: 0.25 +/- 0.02; FPL-FPI: 0.29 +/- 0.03) although stronger than FDI-FPI. Last, CIS from within FDI and FPI was more than three times stronger (0.70 +/- 0.06 and 0.66 +/- 0.06, respectively) than across these muscles. We discuss present and previous findings within the framework of muscle-pair specific distribution of common input to hand muscles based on their functional role in grasping.

Exploring the Role of PGC-1α in Defining Nuclear Organisation in Skeletal Muscle Fibres.

Science.gov (United States)

Ross, Jacob A; Pearson, Adam; Levy, Yotam; Cardel, Bettina; Handschin, Christoph; Ochala, Julien

2017-06-01

Muscle fibres are multinucleated cells, with each nucleus controlling the protein synthesis in a finite volume of cytoplasm termed the myonuclear domain (MND). What determines MND size remains unclear. In the present study, we aimed to test the hypothesis that the level of expression of the transcriptional coactivator PGC-1α and subsequent activation of the mitochondrial biogenesis are major contributors. Hence, we used two transgenic mouse models with varying expression of PGC-1α in skeletal muscles. We isolated myofibres from the fast twitch extensor digitorum longus (EDL) and slow twitch diaphragm muscles. We then membrane-permeabilised them and analysed the 3D spatial arrangements of myonuclei. In EDL muscles, when PGC-1α is over-expressed, MND volume decreases; whereas, when PGC-1α is lacking, no change occurs. In the diaphragm, no clear difference was noted. This indicates that PGC-1α and the related mitochondrial biogenesis programme are determinants of MND size. PGC-1α may facilitate the addition of new myonuclei in order to reach MND volumes that can support an increased mitochondrial density. J. Cell. Physiol. 232: 1270-1274, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Upper motor neurone modulation of the structure of the terminal cisternae in rat skeletal muscle fibres.

Science.gov (United States)

Dulhunty, A F; Gage, P W; Valois, A A

1981-12-23

There are fewer indentations on the flat surfaces of terminal cisternae in soleus (slow-twitch) than in extensor digitorum longus (EDL, fast-twitch) muscle fibres of rats. Following mid-thoracic spinal cord transection, there is an increase in the number of indentations in soleus fibres but no change in EDL fibres. The increase in the numbers of indentations after spinal cord transections is correlated with changes in the contractile and charge movement properties of the soleus fibres so that they resemble normal EDL fibres. The indentations appear to have an important role in excitation-contraction coupling.

Ultrasound of the elbow with emphasis on detailed assessment of ligaments, tendons, and nerves

International Nuclear Information System (INIS)

De Maeseneer, Michel; Brigido, Monica Kalume; Antic, Marijana; Lenchik, Leon; Milants, Annemieke; Vereecke, Evie; Jager, Tjeerd; Shahabpour, Maryam

2015-01-01

Highlights: •Medial and lateral tendons: the different muscles forming these tendons can be followed up to the insertion. The imaging anatomy is reviewed. •Medial and lateral ligaments: the anatomy is complex and specialized imaging planes and arm positions are necessary for accurate assessment. •Biceps tendon: the anatomy of the distal biceps and lacertus fibrosus are discussed and illustrated with cadaveric correlation. •US imaging of the nerves about the elbow and visualization of the possible compression points is discussed. -- Abstract: The high resolution and dynamic capability of ultrasound make it an excellent tool for assessment of superficial structures. The ligaments, tendons, and nerves about the elbow can be fully evaluated with ultrasound. The medial collateral ligament consists of an anterior and posterior band that can easily be identified. The lateral ligament complex consists of the radial collateral ligament, ulnar insertion of the annular ligament, and lateral ulnar collateral ligament, easily identified with specialized probe positioning. The lateral ulnar collateral ligament can best be seen in the cobra position. On ultrasound medial elbow tendons can be followed nearly up to their common insertion. The pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis can be identified. The laterally located brachioradialis and extensor carpi radialis longus insert on the supracondylar ridge. The other lateral tendons can be followed up to their common insertion on the lateral epicondyle. The extensor digitorum, extensor carpi radialis brevis, extensor digiti minimi, and extensor carpi ulnaris can be differentiated. The distal biceps tendon is commonly bifid. For a complete assessment of the distal biceps tendon specialized views are necessary. These include an anterior axial approach, medial and lateral approach, and cobra position. In the cubital tunnel the ulnar nerve is covered by the ligament of Osborne

Ultrasound of the elbow with emphasis on detailed assessment of ligaments, tendons, and nerves

Energy Technology Data Exchange (ETDEWEB)

De Maeseneer, Michel, E-mail: Michel.demaeseneer@uzbrussel.be [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Brigido, Monica Kalume, E-mail: Mbrigido@med.umich.edu [Department of Radiology, University of Michigan, Ann Arbor, MI (United States); Antic, Marijana, E-mail: Misscroa@gmail.com [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Lenchik, Leon, E-mail: Llenchik@wakehealth.edu [Department of Radiology, Wake Forest University, Winston-Salem, NC (United States); Milants, Annemieke, E-mail: Annemieke.Milants@gmail.com [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Vereecke, Evie, E-mail: Evie.Vereecke@kuleuven-kulak.be [Department of Anatomy, KULAK, Katholieke Universiteit Leuven, Campus Kortrijk, Kortrijk (Belgium); Jager, Tjeerd [Aalsters Stedelijk Ziekenhuis, Aalst (Belgium); Shahabpour, Maryam, E-mail: Maryam.Shahabpour@uzbrussel.be [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium)

2015-04-15

Highlights: •Medial and lateral tendons: the different muscles forming these tendons can be followed up to the insertion. The imaging anatomy is reviewed. •Medial and lateral ligaments: the anatomy is complex and specialized imaging planes and arm positions are necessary for accurate assessment. •Biceps tendon: the anatomy of the distal biceps and lacertus fibrosus are discussed and illustrated with cadaveric correlation. •US imaging of the nerves about the elbow and visualization of the possible compression points is discussed. -- Abstract: The high resolution and dynamic capability of ultrasound make it an excellent tool for assessment of superficial structures. The ligaments, tendons, and nerves about the elbow can be fully evaluated with ultrasound. The medial collateral ligament consists of an anterior and posterior band that can easily be identified. The lateral ligament complex consists of the radial collateral ligament, ulnar insertion of the annular ligament, and lateral ulnar collateral ligament, easily identified with specialized probe positioning. The lateral ulnar collateral ligament can best be seen in the cobra position. On ultrasound medial elbow tendons can be followed nearly up to their common insertion. The pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis can be identified. The laterally located brachioradialis and extensor carpi radialis longus insert on the supracondylar ridge. The other lateral tendons can be followed up to their common insertion on the lateral epicondyle. The extensor digitorum, extensor carpi radialis brevis, extensor digiti minimi, and extensor carpi ulnaris can be differentiated. The distal biceps tendon is commonly bifid. For a complete assessment of the distal biceps tendon specialized views are necessary. These include an anterior axial approach, medial and lateral approach, and cobra position. In the cubital tunnel the ulnar nerve is covered by the ligament of Osborne

Sarcoplasmic reticulum function in slow- and fast-twitch skeletal muscles from mdx mice.

Science.gov (United States)

Divet, Alexandra; Huchet-Cadiou, Corinne

2002-08-01

The aim of the present study was to establish whether alterations in sarcoplasmic reticulum function are involved in the abnormal Ca(2+) homeostasis of skeletal muscle in mice with muscular dystrophy ( mdx). The properties of the sarcoplasmic reticulum and contractile proteins of fast- and slow-twitch muscles were therefore investigated in chemically skinned fibres isolated from the extensor digitorum longus (EDL) and soleus muscles of normal (C57BL/10) and mdx mice at 4 and 11 weeks of development. Sarcoplasmic reticulum Ca(2+) uptake, estimated by the Ca(2+) release following exposure to caffeine, was significantly slower in mdx mice, while the maximal Ca(2+) quantity did not differ in either type of skeletal muscle at either stage of development. In 4-week-old mice spontaneous sarcoplasmic reticulum Ca(2+) leakage was observed in EDL and soleus fibres and this was more pronounced in mdx mice. In addition, the maximal Ca(2+)-activated tension was smaller in mdx than in normal fibres, while the Ca(2+) sensitivity of the contractile apparatus was not significantly different. These results indicate that mdx hindlimb muscles are affected differently by the disease process and suggest that a reduced ability of the Ca(2+)-ATPase to load Ca(2+) and a leaky sarcoplasmic reticulum membrane may be involved in the altered intracellular Ca(2+) homeostasis.

Proteomic and carbonylation profile analysis of rat skeletal muscles following acute swimming exercise.

Directory of Open Access Journals (Sweden)

Francesca Magherini

Full Text Available Previous studies by us and other groups characterized protein expression variation following long-term moderate training, whereas the effects of single bursts of exercise are less known. Making use of a proteomic approach, we investigated the effects of acute swimming exercise (ASE on protein expression and carbonylation patterns in two hind limb muscles: the Extensor Digitorum Longus (EDL and the Soleus, mostly composed of fast-twitch and slow-twitch fibres, respectively. Carbonylation is one of the most common oxidative modifications of proteins and a marker of oxidative stress. In fact, several studies suggest that physical activity and the consequent increase in oxygen consumption can lead to increase in reactive oxygen and nitrogen species (RONS production, hence the interest in examining the impact of RONS on skeletal muscle proteins following ASE. Results indicate that protein expression is unaffected by ASE in both muscle types. Unexpectedly, the protein carbonylation level was reduced following ASE. In particular, the analysis found 31 and 5 spots, in Soleus and EDL muscles respectively, whose carbonylation is reduced after ASE. Lipid peroxidation levels in Soleus were markedly reduced as well. Most of the decarbonylated proteins are involved either in the regulation of muscle contractions or in the regulation of energy metabolism. A number of hypotheses may be advanced to account for such results, which will be addressed in future studies.

Effect of sepsis on calcium uptake and content in skeletal muscle and regulation in vitro by calcium of total and myofibrillar protein breakdown in control and septic muscle: Results from a preliminary study

International Nuclear Information System (INIS)

Benson, D.W.; Hasselgren, P.O.; Hiyama, D.T.; James, J.H.; Li, S.; Rigel, D.F.; Fischer, J.E.

1989-01-01

Because high calcium concentration in vitro stimulates muscle proteolysis, calcium has been implicated in the pathogenesis of increased muscle breakdown in different catabolic conditions. Protein breakdown in skeletal muscle is increased during sepsis, but the effect of sepsis on muscle calcium uptake and content is not known. In this study the influence of sepsis, induced in rats by cecal ligation and puncture, on muscle calcium uptake and content was studied. Sixteen hours after cecal ligation and puncture or sham operation, calcium content of the extensor digitorum longus (EDL) and soleus (SOL) muscles was determined with an atomic absorption spectrometer. Calcium uptake was measured in intact SOL muscles incubated in the presence of calcium 45 (45Ca) for between 1 and 120 minutes. Total and myofibrillar protein breakdown was determined in SOL muscles, incubated in the presence of different calcium concentrations (0; 2.5; 5.0 mmol/L), and measured as release into the incubation medium of tyrosine and 3-methylhistidine (3-MH), respectively. Calcium content was increased by 51% (p less than 0.001) during sepsis in SOL and by 10% (p less than 0.05) in EDL muscle. There was no difference in 45Ca uptake between control and septic muscles during the early phase (1 to 5 minutes) of incubation. During more extended incubation (30 to 120 minutes), muscles from septic rats took up significantly more 45Ca than control muscles (p less than 0.05). Tyrosine release by incubated SOL muscles from control and septic rats was increased when calcium was added to the incubation medium, and at a calcium concentration of 2.5 mmol/L, the increase in tyrosine release was greater in septic than in control muscle. Addition of calcium to the incubation medium did not affect 3-MH release in control or septic muscle

Ionic currents and charge movements in organ-cultured rat skeletal muscle.

Science.gov (United States)

Hollingworth, S; Marshall, M W; Robson, E

1984-12-01

The middle of the fibre voltage-clamp technique was used to measure ionic currents and non-linear charge movements in intact, organ-cultured (in vitro denervated) mammalian fast-twitch (rat extensor digitorum longus) muscle fibres. Muscle fibres organ cultured for 4 days can be used as electrophysiological and morphological models for muscles in vivo denervated for the same length of time. Sodium currents in organ-cultured muscle fibres are similar to innervated fibres except that in the temperature range 0-20 degrees C (a) in the steady state, the voltage distribution of inactivation in cultured fibres is shifted negatively some 20 mV; (b) at the same temperature and membrane potential, the time constant of inactivation in cultured fibres is about twice that of innervated fibres. Potassium currents in innervated and cultured fibres at 15 degrees C can be fitted with the Hodgkin-Huxley n variable raised to the second power. Despite the large range we would estimate that the maximum value of the steady-state potassium conductance of cultured fibres is about one-half that of innervated fibres. The estimated maximum amount of charge moved in cultured fibre is about one-third that in innervated fibres. Compared to innervated fibres, culturing doubles the kinetics of the decay phase of charge movement. The possibility of a negative shift of the voltage distribution of charge movements in cultured fibres is discussed.

A mouse anti-myostatin antibody increases muscle mass and improves muscle strength and contractility in the mdx mouse model of Duchenne muscular dystrophy and its humanized equivalent, domagrozumab (PF-06252616), increases muscle volume in cynomolgus monkeys.

Science.gov (United States)

St Andre, Michael; Johnson, Mark; Bansal, Prashant N; Wellen, Jeremy; Robertson, Andrew; Opsahl, Alan; Burch, Peter M; Bialek, Peter; Morris, Carl; Owens, Jane

2017-11-09

The treatments currently approved for Duchenne muscular dystrophy (DMD), a progressive skeletal muscle wasting disease, address the needs of only a small proportion of patients resulting in an urgent need for therapies that benefit all patients regardless of the underlying mutation. Myostatin is a member of the transforming growth factor-β (TGF-β) family of ligands and is a negative regulator of skeletal muscle mass. Loss of myostatin has been shown to increase muscle mass and improve muscle function in both normal and dystrophic mice. Therefore, myostatin blockade via a specific antibody could ameliorate the muscle weakness in DMD patients by increasing skeletal muscle mass and function, thereby reducing patients' functional decline. A murine anti-myostatin antibody, mRK35, and its humanized analog, domagrozumab, were developed and their ability to inhibit several TGB-β ligands was measured using a cell-based Smad-activity reporter system. Normal and mdx mice were treated with mRK35 to examine the antibody's effect on body weight, lean mass, muscle weights, grip strength, ex vivo force production, and fiber size. The humanized analog (domagrozumab) was tested in non-human primates (NHPs) for changes in skeletal muscle mass and volume as well as target engagement via modulation of circulating myostatin. Both the murine and human antibodies are specific and potent inhibitors of myostatin and GDF11. mRK35 is able to increase body weight, lean mass, and muscle weights in normal mice. In mdx mice, mRK35 significantly increased body weight, muscle weights, grip strength, and ex vivo force production in the extensor digitorum longus (EDL) muscle. Further, tibialis anterior (TA) fiber size was significantly increased. NHPs treated with domagrozumab demonstrated a dose-dependent increase in lean mass and muscle volume and exhibited increased circulating levels of myostatin demonstrating target engagement. We demonstrated that the potent anti-myostatin antibody mRK35 and

Time course in calpain activity and autolysis in slow and fast skeletal muscle during clenbuterol treatment.

Science.gov (United States)

Douillard, Aymeric; Galbes, Olivier; Rossano, Bernadette; Vernus, Barbara; Bonnieu, Anne; Candau, Robin; Py, Guillaume

2011-02-01

Calpains are Ca2+ cysteine proteases that have been proposed to be involved in the cytoskeletal remodeling and wasting of skeletal muscle. Cumulative evidence also suggests that β2-agonists can lead to skeletal muscle hypertrophy through a mechanism probably related to calcium-dependent proteolytic enzyme. The aim of our study was to monitor calpain activity as a function of clenbuterol treatment in both slow and fast phenotype rat muscles. For this purpose, for 21 days we followed the time course of the calpain activity and of the ubiquitous calpain 1 and 2 autolysis, as well as muscle remodeling in the extensor digitorum longus (EDL) and soleus muscles of male Wistar rats treated daily with clenbuterol (4 mg·kg-1). A slow to fast fiber shift was observed in both the EDL and soleus muscles after 9 days of treatment, while hypertrophy was observed only in EDL after 9 days of treatment. Soleus muscle but not EDL muscle underwent an early apoptonecrosis phase characterized by hematoxylin and eosin staining. Total calpain activity was increased in both the EDL and soleus muscles of rats treated with clenbuterol. Moreover, calpain 1 autolysis increased significantly after 14 days in the EDL, but not in the soleus. Calpain 2 autolysis increased significantly in both muscles 6 hours after the first clenbuterol injection, indicating that clenbuterol-induced calpain 2 autolysis occurred earlier than calpain 1 autolysis. Together, these data suggest a preferential involvement of calpain 2 autolysis compared with calpain 1 autolysis in the mechanisms underlying the clenbuterol-induced skeletal muscle remodeling.

Cytoskeleton, L-type Ca2+ and stretch activated channels in injured skeletal muscle

Directory of Open Access Journals (Sweden)

Fabio Francini

2013-07-01

Full Text Available The extra-sarcomeric cytoskeleton (actin microfilaments and anchoring proteins is involved in maintaining the sarco-membrane stiffness and integrity and in turn the mechanical stability and function of the intra- and sub-sarcoplasmic proteins. Accordingly, it regulates Ca2+ entry through the L-type Ca2+ channels and the mechano-sensitivity of the stretch activated channels (SACs. Moreover, being intra-sarcomeric cytoskeleton bound to costameric proteins and other proteins of the sarcoplasma by intermediate filaments, as desmin, it integrates the properties of the sarcolemma with the skeletal muscle fibres contraction. The aim of this research was to compare the cytoskeleton, SACs and the ECC alterations in two different types of injured skeletal muscle fibres: by muscle denervation and mechanical overload (eccentric contraction. Experiments on denervation were made in isolated Soleus muscle of male Wistar rats; forced eccentric-contraction (EC injury was achieved in Extensor Digitorum Longus muscles of Swiss mice. The method employed conventional intracellular recording with microelectrodes inserted in a single fibre of an isolated skeletal muscle bundle. The state of cytoskeleton was evaluated by recording SAC currents and by evaluating the resting membrane potential (RMP value determined in current-clamp mode. The results demonstrated that in both injured skeletal muscle conditions the functionality of L-type Ca2+ current, ICa, was affected. In parallel, muscle fibres showed an increase of the resting membrane permeability and of the SAC current. These issues, together with a more depolarized RMP are an index of altered cytoskeleton. In conclusion, we found a symilar alteration of ICa, SAC and cytoskeleton in both injured skeletal muscle conditions.

Effect of ascorbic acid on fatigue of skeletal muscle fibres in long term cold exposed sprague dawley rats

International Nuclear Information System (INIS)

Rashid, A.; Ayub, M.

2011-01-01

On exposure to prolonged cold temperature, the body responds for effective heat production both by shivering and non-shivering thermo genesis. Cold exposure increases the production of reactive oxygen species which influence the sarcoplasmic reticulum Ca/sup ++/ release from the skeletal muscles and affect their contractile properties. The role of ascorbic acid supplementation on force of contraction during fatigue of cold exposed skeletal muscles was evaluated in this study. Method: Ninety healthy, male Sprague Dawley rats were randomly divided into three groups of control, cold exposed, and cold exposed with ascorbic acid 500 mg/L supplementation mixed in drinking water. Group II and III were given cold exposure by keeping their cages in ice-filled tubs for 1 hr/day for one month. After one month, the extensor digitorum longus muscle was dissected out and force of contraction during fatigue in the skeletal muscle fibres was analysed on a computerised data acquisition system. Results: The cold exposed group showed a significant delay in the force of contraction during fatigue of skeletal muscle fibres compared to control group. Group III showed easy fatigability and a better force of contraction than the cold exposed group. Conclusions: Ascorbic acid increases the force of contraction and decreases resistance to fatigue in the muscles exposed to chronic cold. (author)

An MRI volumetric study for leg muscles in congenital clubfoot.

Science.gov (United States)

Ippolito, Ernesto; Dragoni, Massimiliano; Antonicoli, Marco; Farsetti, Pasquale; Simonetti, Giovanni; Masala, Salvatore

2012-10-01

To investigate both volume and length of the three muscle compartments of the normal and the affected leg in unilateral congenital clubfoot. Volumetric magnetic resonance imaging (VMRI) of the anterior, lateral and postero-medial muscular compartments of both the normal and the clubfoot leg was obtained in three groups of seven patients each, whose mean age was, respectively, 4.8 months, 11.1 months and 4.7 years. At diagnosis, all the unilateral congenital clubfeet had a Pirani score ranging from 4.5 to 5.5 points, and all of them had been treated according to a strict Ponseti protocol. All the feet had percutaneous lengthening of the Achilles tendon. A mean difference in both volume and length was found between the three muscular compartments of the leg, with the muscles of the clubfoot side being thinner and shorter than those of the normal side. The distal tendon of the tibialis anterior, peroneus longus and triceps surae (Achilles tendon) were longer than normal on the clubfoot side. Our study shows that the three muscle compartments of the clubfoot leg are thinner and shorter than normal in the patients of the three groups. The difference in the musculature volume of the postero-medial compartment between the normal and the affected side increased nine-fold from age group 2 to 3, while the difference in length increased by 20 %, thus, showing that the muscles of the postero-medial compartment tend to grow in both thickness and length much less than the muscles of the other leg compartments.

Effects of β₂-agonists on force during and following anoxia in rat extensor digitorum longus muscle

DEFF Research Database (Denmark)

Fredsted, A; Gissel, H; Ortenblad, N

2012-01-01

of salbutamol on force recovery were prevented by blocking the Na(+),K(+)- pumps with ouabain or by blocking glycolysis with 2-deoxyglucose. Dibutyryl cAMP (1 mM) or theophylline (1 mM) also improved force recovery remarkably. In anoxic muscles, salbutamol decreased intracellular Na(+), increased (86)Rb uptake...

Chronic clenbuterol treatment compromises force production without directly altering skeletal muscle contractile machinery

Science.gov (United States)

Py, G; Ramonatxo, C; Sirvent, P; Sanchez, A M J; Philippe, A G; Douillard, A; Galbès, O; Lionne, C; Bonnieu, A; Chopard, A; Cazorla, O; Lacampagne, A; Candau, R B

2015-01-01

Clenbuterol is a β2-adrenergic receptor agonist known to induce skeletal muscle hypertrophy and a slow-to-fast phenotypic shift. The aim of the present study was to test the effects of chronic clenbuterol treatment on contractile efficiency and explore the underlying mechanisms, i.e. the muscle contractile machinery and calcium-handling ability. Forty-three 6-week-old male Wistar rats were randomly allocated to one of six groups that were treated with either subcutaneous equimolar doses of clenbuterol (4 mg kg−1 day−1) or saline solution for 9, 14 or 21 days. In addition to the muscle hypertrophy, although an 89% increase in absolute maximal tetanic force (Po) was noted, specific maximal tetanic force (sPo) was unchanged or even depressed in the slow twitch muscle of the clenbuterol-treated rats (P muscle contraction and relaxation force kinetics indicated that clenbuterol treatment significantly reduced the rate constant of force development and the slow and fast rate constants of relaxation in extensor digitorum longus muscle (P fast rate constant of relaxation in soleus muscle (P fibres (fast twitch fibres) from clenbuterol-treated animals demonstrated decreased amplitude after 14 days (−19%, P < 0.01) and 21 days (−25%, P < 0.01). In conclusion, we showed that chronic clenbuterol treatment reduces contractile efficiency, with altered contraction and relaxation kinetics, but without directly altering the contractile machinery. Lower Ca2+ release during contraction could partially explain these deleterious effects. PMID:25656230

Gestational Undernourishment Modifies the Composition of Skeletal Muscle Transverse Tubule Membranes and the Mechanical Properties of Muscles in Newborn Rats

Directory of Open Access Journals (Sweden)

Ricardo Tonathiu Ramírez-Oseguera

2013-10-01

Full Text Available Backgroud/Aims: Skeletal muscle (SM constitutes more than 40% of the body weight in adulthood. Transports dietary glucose mainly through the insulin-dependent glucose transporter (Glut-4 located in the Transverse tubule membrane system (TT. The TT development ends shortly after birth. The TT membrane hosts the proteins involved in excitation-contraction coupling and glucose uptake. Glycaemic regulation through movement is a key function of fully developed skeletal muscle. In this study, we aimed to characterize the effect of gestational undernourishment (GUN in rats GLUT-4 expression and on the protein/lipid content of the TT membranes. We also examined the effect of GUN on the mechanical properties of muscles as an indication of the metabolic condition of the SM at birth. Methods: Isolated TT membrane from SM of GUN rats were used to study lipid/protein content and protein stability by differential scanning calorimetry. The effect of GUN on the SM mechanical properties was determined in isolated Extensor Digitorum Longus (EDL muscle. Results: We demonstrate that compared to control, GUN in the new-born produces; i decreases body weight; ii diminution in SM mass; iii decreases the formation of TT membranes; iv expresses TT membrane proteins with higher thermal stability. The TT membrane expression of GLUT-4 in GUN offspring was twice that of controls. The isolated EDL of GUN offspring was 20% stronger as measured by contractile force and more resistant to fatigue relative to controls. Conclusion; These results provide the first evidence of adaptive changes of the SM in new-borns exposed to severe gestational food restriction. The effects of GUN on muscle at birth are the first step toward detrimental SM metabolic function, contributing to the physiopathology of metabolic diseases in adulthood.

Gestational undernourishment modifies the composition of skeletal muscle transverse tubule membranes and the mechanical properties of muscles in newborn rats.

Science.gov (United States)

Ramírez-Oseguera, Ricardo Tonathiu; Jiménez-Garduño, Aura Matilde; Alvarez, Rocío; Heine, Katharina; Pinzón-Estrada, Enrique; Torres-Saldaña, Ismael; Ortega, Alicia

2013-01-01

[corrected] Skeletal muscle (SM) constitutes more than 40% of the body weight in adulthood. Transports dietary glucose mainly through the insulin-dependent glucose transporter (Glut-4) located in the Transverse tubule membrane system (TT). The TT development ends shortly after birth. The TT membrane hosts the proteins involved in excitation-contraction coupling and glucose uptake. Glycaemic regulation through movement is a key function of fully developed skeletal muscle. In this study, we aimed to characterize the effect of gestational undernourishment (GUN) in rats GLUT-4 expression and on the protein/lipid content of the TT membranes. We also examined the effect of GUN on the mechanical properties of muscles as an indication of the metabolic condition of the SM at birth. Isolated TT membrane from SM of GUN rats were used to study lipid/protein content and protein stability by differential scanning calorimetry. The effect of GUN on the SM mechanical properties was determined in isolated Extensor Digitorum Longus (EDL) muscle. We demonstrate that compared to control, GUN in the new-born produces; i) decreases body weight; ii) diminution in SM mass; iii) decreases the formation of TT membranes; iv) expresses TT membrane proteins with higher thermal stability. The TT membrane expression of GLUT-4 in GUN offspring was twice that of controls. The isolated EDL of GUN offspring was 20% stronger as measured by contractile force and more resistant to fatigue relative to controls. These results provide the first evidence of adaptive changes of the SM in new-borns exposed to severe gestational food restriction. The effects of GUN on muscle at birth are the first step toward detrimental SM metabolic function, contributing to the physiopathology of metabolic diseases in adulthood. © 2013 S. Karger AG, Basel

Changes in contractile activation characteristics of rat fast and slow skeletal muscle fibres during regeneration.

Science.gov (United States)

Gregorevic, Paul; Plant, David R; Stupka, Nicole; Lynch, Gordon S

2004-07-15

Damaged skeletal muscle fibres are replaced with new contractile units via muscle regeneration. Regenerating muscle fibres synthesize functionally distinct isoforms of contractile and regulatory proteins but little is known of their functional properties during the regeneration process. An advantage of utilizing single muscle fibre preparations is that assessment of their function is based on the overall characteristics of the contractile apparatus and regulatory system and as such, these preparations are sensitive in revealing not only coarse, but also subtle functional differences between muscle fibres. We examined the Ca(2+)- and Sr(2+)-activated contractile characteristics of permeabilized fibres from rat fast-twitch (extensor digitorum longus) and slow-twitch (soleus) muscles at 7, 14 and 21 days following myotoxic injury, to test the hypothesis that fibres from regenerating fast and slow muscles have different functional characteristics to fibres from uninjured muscles. Regenerating muscle fibres had approximately 10% of the maximal force producing capacity (P(o)) of control (uninjured) fibres, and an altered sensitivity to Ca(2+) and Sr(2+) at 7 days post-injury. Increased force production and a shift in Ca(2+) sensitivity consistent with fibre maturation were observed during regeneration such that P(o) was restored to 36-45% of that in control fibres by 21 days, and sensitivity to Ca(2+) and Sr(2+) was similar to that of control (uninjured) fibres. The findings support the hypothesis that regenerating muscle fibres have different contractile activation characteristics compared with mature fibres, and that they adopt properties of mature fast- or slow-twitch muscle fibres in a progressive manner as the regeneration process is completed.

A Reduction in Selenoprotein S Amplifies the Inflammatory Profile of Fast-Twitch Skeletal Muscle in the mdx Dystrophic Mouse.

Science.gov (United States)

Wright, Craig Robert; Allsopp, Giselle Larissa; Addinsall, Alex Bernard; McRae, Natasha Lee; Andrikopoulos, Sofianos; Stupka, Nicole

2017-01-01

Excessive inflammation is a hallmark of muscle myopathies, including Duchenne muscular dystrophy (DMD). There is interest in characterising novel genes that regulate inflammation due to their potential to modify disease progression. Gene polymorphisms in Selenoprotein S ( Seps1 ) are associated with elevated proinflammatory cytokines, and in vitro SEPS1 is protective against inflammatory stress. Given that SEPS1 is highly expressed in skeletal muscle, we investigated whether the genetic reduction of Seps1 exacerbated inflammation in the mdx mouse. F1 male mdx mice with a heterozygous Seps1 deletion ( mdx : Seps1 -/+ ) were generated. The mdx:Seps1 -/+ mice had a 50% reduction in SEPS1 protein expression in hindlimb muscles. In the extensor digitorum longus (EDL) muscles, mRNA expression of monocyte chemoattractant protein 1 ( Mcp-1 ) ( P = 0.034), macrophage marker F4/80 ( P = 0.030), and transforming growth factor-β1 ( Tgf-β1 ) ( P = 0.056) were increased in mdx:Seps1 -/+ mice. This was associated with a reduction in muscle fibre size; however, ex vivo EDL muscle strength and endurance were unaltered. In dystrophic slow twitch soleus muscles, SEPS1 reduction had no effect on the inflammatory profile nor function. In conclusion, the genetic reduction of Seps1 appears to specifically exacerbate the inflammatory profile of fast-twitch muscle fibres, which are typically more vulnerable to degeneration in dystrophy.

Two weeks of metformin treatment induces AMPK-dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

Science.gov (United States)

Kristensen, Jonas Møller; Treebak, Jonas T.; Schjerling, Peter; Goodyear, Laurie

2014-01-01

Metformin-induced activation of the 5′-AMP-activated protein kinase (AMPK) has been associated with enhanced glucose uptake in skeletal muscle, but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent on AMPK signaling. Oral doses of metformin or saline treatment were given to muscle-specific kinase dead (KD) AMPKα2 mice and wild-type (WT) littermates either once or chronically for 2 wk. Soleus and extensor digitorum longus muscles were used for measurements of glucose transport and Western blot analyses. Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (∼45%, P metformin treatment. Insulin signaling at the level of Akt and TBC1D4 protein expression as well as Akt Thr308/Ser473 and TBC1D4 Thr642/Ser711 phosphorylation were not changed by metformin treatment. Also, protein expressions of Rab4, GLUT4, and hexokinase II were unaltered after treatment. The acute metformin treatment did not affect glucose uptake in muscle of either of the genotypes. In conclusion, we provide novel evidence for a role of AMPK in potentiating the effect of insulin on glucose uptake in soleus muscle in response to chronic metformin treatment. PMID:24644243

Glucose uptake during contraction in isolated skeletal muscles from neuronal nitric oxide synthase μ knockout mice.

Science.gov (United States)

Hong, Yet Hoi; Frugier, Tony; Zhang, Xinmei; Murphy, Robyn M; Lynch, Gordon S; Betik, Andrew C; Rattigan, Stephen; McConell, Glenn K

2015-05-01

Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation is observed in individuals with Type 2 diabetes compared with healthy individuals. Therefore, NO appears to play an important role in mediating muscle glucose uptake during contraction. In this study, we investigated the involvement of neuronal NOSμ (nNOSμ), the main NOS isoform activated during contraction, on skeletal muscle glucose uptake during ex vivo contraction. Extensor digitorum longus muscles were isolated from nNOSμ(-/-) and nNOSμ(+/+) mice. Muscles were contracted ex vivo in a temperature-controlled (30°C) organ bath with or without the presence of the NOS inhibitor N(G)-monomethyl-l-arginine (L-NMMA) and the NOS substrate L-arginine. Glucose uptake was determined by radioactive tracers. Skeletal muscle glucose uptake increased approximately fourfold during contraction in muscles from both nNOSμ(-/-) and nNOSμ(+/+) mice. L-NMMA significantly attenuated the increase in muscle glucose uptake during contraction in both genotypes. This attenuation was reversed by L-arginine, suggesting that L-NMMA attenuated the increase in muscle glucose uptake during contraction by inhibiting NOS and not via a nonspecific effect of the inhibitor. Low levels of NOS activity (~4%) were detected in muscles from nNOSμ(-/-) mice, and there was no evidence of compensation from other NOS isoform or AMP-activated protein kinase which is also involved in mediating muscle glucose uptake during contraction. These results indicate that NO regulates skeletal muscle glucose uptake during ex vivo contraction independently of nNOSμ. Copyright © 2015 the American Physiological Society.

Adaptation of Mouse Skeletal Muscle to Long-Term Microgravity in the MDS Mission

Science.gov (United States)

Camerino, Giulia M.; Bianchini, Elisa; Ciciliot, Stefano; Danieli-Betto, Daniela; Dobrowolny, Gabriella; Furlan, Sandra; Germinario, Elena; Goto, Katsumasa; Gutsmann, Martina; Kawano, Fuminori; Nakai, Naoya; Ohira, Takashi; Ohno, Yoshitaka; Picard, Anne; Salanova, Michele; Schiffl, Gudrun; Blottner, Dieter; Musarò, Antonio; Ohira, Yoshinobu; Betto, Romeo; Conte, Diana; Schiaffino, Stefano

2012-01-01

The effect of microgravity on skeletal muscles has so far been examined in rat and mice only after short-term (5–20 day) spaceflights. The mice drawer system (MDS) program, sponsored by Italian Space Agency, for the first time aimed to investigate the consequences of long-term (91 days) exposure to microgravity in mice within the International Space Station. Muscle atrophy was present indistinctly in all fiber types of the slow-twitch soleus muscle, but was only slightly greater than that observed after 20 days of spaceflight. Myosin heavy chain analysis indicated a concomitant slow-to-fast transition of soleus. In addition, spaceflight induced translocation of sarcolemmal nitric oxide synthase-1 (NOS1) into the cytosol in soleus but not in the fast-twitch extensor digitorum longus (EDL) muscle. Most of the sarcolemmal ion channel subunits were up-regulated, more in soleus than EDL, whereas Ca2+-activated K+ channels were down-regulated, consistent with the phenotype transition. Gene expression of the atrophy-related ubiquitin-ligases was up-regulated in both spaceflown soleus and EDL muscles, whereas autophagy genes were in the control range. Muscle-specific IGF-1 and interleukin-6 were down-regulated in soleus but up-regulated in EDL. Also, various stress-related genes were up-regulated in spaceflown EDL, not in soleus. Altogether, these results suggest that EDL muscle may resist to microgravity-induced atrophy by activating compensatory and protective pathways. Our study shows the extended sensitivity of antigravity soleus muscle after prolonged exposition to microgravity, suggests possible mechanisms accounting for the resistance of EDL, and individuates some molecular targets for the development of countermeasures. PMID:22470446

Adaptation of mouse skeletal muscle to long-term microgravity in the MDS mission.

Directory of Open Access Journals (Sweden)

Dorianna Sandonà

Full Text Available The effect of microgravity on skeletal muscles has so far been examined in rat and mice only after short-term (5-20 day spaceflights. The mice drawer system (MDS program, sponsored by Italian Space Agency, for the first time aimed to investigate the consequences of long-term (91 days exposure to microgravity in mice within the International Space Station. Muscle atrophy was present indistinctly in all fiber types of the slow-twitch soleus muscle, but was only slightly greater than that observed after 20 days of spaceflight. Myosin heavy chain analysis indicated a concomitant slow-to-fast transition of soleus. In addition, spaceflight induced translocation of sarcolemmal nitric oxide synthase-1 (NOS1 into the cytosol in soleus but not in the fast-twitch extensor digitorum longus (EDL muscle. Most of the sarcolemmal ion channel subunits were up-regulated, more in soleus than EDL, whereas Ca(2+-activated K(+ channels were down-regulated, consistent with the phenotype transition. Gene expression of the atrophy-related ubiquitin-ligases was up-regulated in both spaceflown soleus and EDL muscles, whereas autophagy genes were in the control range. Muscle-specific IGF-1 and interleukin-6 were down-regulated in soleus but up-regulated in EDL. Also, various stress-related genes were up-regulated in spaceflown EDL, not in soleus. Altogether, these results suggest that EDL muscle may resist to microgravity-induced atrophy by activating compensatory and protective pathways. Our study shows the extended sensitivity of antigravity soleus muscle after prolonged exposition to microgravity, suggests possible mechanisms accounting for the resistance of EDL, and individuates some molecular targets for the development of countermeasures.

Tissue-specific Role of the Na,K-ATPase α2 Isozyme in Skeletal Muscle*

Science.gov (United States)

Radzyukevich, Tatiana L.; Neumann, Jonathon C.; Rindler, Tara N.; Oshiro, Naomi; Goldhamer, David J.; Lingrel, Jerry B.; Heiny, Judith A.

2013-01-01

The Na,K-ATPase α2 isozyme is the major Na,K-ATPase of mammalian skeletal muscle. This distribution is unique compared with most other cells, which express mainly the Na,K-ATPase α1 isoform, but its functional significance is not known. We developed a gene-targeted mouse (skα2−/−) in which the α2 gene (Atp1a2) is knocked out in the skeletal muscles, and examined the consequences for exercise performance, membrane potentials, contractility, and muscle fatigue. Targeted knockout was confirmed by genotyping, Western blot, and immunohistochemistry. Skeletal muscle cells of skα2−/− mice completely lack α2 protein and have no α2 in the transverse tubules, where its expression is normally enhanced. The α1 isoform, which is normally enhanced on the outer sarcolemma, is up-regulated 2.5-fold without change in subcellular targeting. skα2−/− mice are apparently normal under basal conditions but show significantly reduced exercise capacity when challenged to run. Their skeletal muscles produce less force, are unable to increase force to match demand, and show significantly increased susceptibility to fatigue. The impairments affect both fast and slow muscle types. The subcellular targeting of α2 to the transverse tubules is important for this role. Increasing Na,K-ATPase α1 content cannot fully compensate for the loss of α2. The increased fatigability of skα2−/− muscles is reproduced in control extensor digitorum longus muscles by selectively inhibiting α2 enzyme activity with ouabain. These results demonstrate that the Na,K-ATPase α2 isoform performs an acute, isoform-specific role in skeletal muscle. Its activity is regulated by muscle use and enables working muscles to maintain contraction and resist fatigue. PMID:23192345

Myosin phosphorylation potentiates steady-state work output without altering contractile economy of mouse fast skeletal muscles.

Science.gov (United States)

Gittings, William; Bunda, Jordan; Vandenboom, Rene

2018-01-30

Skeletal myosin light chain kinase (skMLCK)-catalyzed phosphorylation of the myosin regulatory light chain (RLC) increases (i.e. potentiates) mechanical work output of fast skeletal muscle. The influence of this event on contractile economy (i.e. energy cost/work performed) remains controversial, however. Our purpose was to quantify contractile economy of potentiated extensor digitorum longus (EDL) muscles from mouse skeletal muscles with (wild-type, WT) and without (skMLCK ablated, skMLCK -/- ) the ability to phosphorylate the RLC. Contractile economy was calculated as the ratio of total work performed to high-energy phosphate consumption (HEPC) during a period of repeated isovelocity contractions that followed a potentiating stimulus (PS). Consistent with genotype, the PS increased RLC phosphorylation measured during, before and after isovelocity contractions in WT but not in skMLCK -/- muscles (i.e. 0.65 and 0.05 mol phosphate mol -1 RLC, respectively). In addition, although the PS enhanced work during repeated isovelocity contractions in both genotypes, the increase was significantly greater in WT than in skMLCK -/- muscles (1.51±0.03 versus 1.10±0.05, respectively; all data P economy calculated for WT muscles was similar to that calculated for skMLCK -/- muscles (i.e. 5.74±0.67 and 4.61±0.71 J kg -1  μmol -1 P, respectively ( P economy. © 2018. Published by The Company of Biologists Ltd.

Rectus abdominis muscle injuries in elite handball players: management and rehabilitation

Directory of Open Access Journals (Sweden)

Balius R

2011-07-01

Full Text Available Ramon Balius1, Carles Pedret2, Laura Pacheco1, Josep Antoni Gutierrez3, Joan Vives4, Jaume Escoda11Consell Català de l’Esport, Generalitat de Catalunya, Barcelona; 2Centro Mapfre de Medicina del Tenis, Barcelona; 3Spanish National Handball Team, Spain; 4Granollers Handball Club, Granollers, Barcelona, SpainAbstract: Muscle injuries generally occur in two-joint muscles with a high percentage of type II fibers during the performance of eccentric activity. Some muscle injuries, such as those located in the adductor longus, a monoarticular muscle, as well as rectus abdominis do not fully comply with these requirements. This study examines five cases of elite handball players with ruptured rectus abdominals. Sonographically, lesions in rectus abdominis are shown as a disruption of the fibrillar pattern with a hematic suffusion that invades the entire lesion. In some of the cases, the ultrasound study was complemented with a MRI. A unified rehabilitation protocol was applied and the return to play time of each handball player ranged between 16 and 22 days, with an average of 18.2 days. Follow-up at 15 months showed no evidence of re-injury or residual discomfort and all of them are playing at their highest level. The aim of this study was to illustrate a feature of handball injury that, as in tennis and volleyball, is uncommon and so far has not been specifically reported. The phenomenon of contralateral abdominal hypertrophy in handball appears in the dominant arm as in tennis and volleyball.Keywords: rectus abdominis, muscle injury, sonography, MRI, handball 

Correlation between Mechanical Properties of the Ankle Muscles and Postural Sway during the Menstrual Cycle.

Science.gov (United States)

Yim, JongEun; Petrofsky, Jerrold; Lee, Haneul

2018-03-01

Ankle and foot injuries are common among athletes and physically active individuals. The most common residual disability, ankle sprain, is characterized by instability along with postural sway. If the supporting structures around a joint become lax, posture stability and balance are also affected. Previous studies have examined muscle stiffness and elasticity and postural sway separately; however, the relationship between these factors is yet unknown. It is well known that the levels of sex hormones, especially estrogen, change in women over the phase of the menstrual cycle. Therefore, this study examined the relationship between the mechanical properties of tissue and balance activity using a non-invasive digital palpation device to determine if they undergo any changes over the menstrual cycle in young women. Sixteen young women with regular menstrual cycles completed the study. Tone, stiffness, and elasticity of the ankle muscles (lateral gastrocnemius, peroneus longus, and tibialis anterior) were measured using a non-invasive digital palpation device. Postural sway was recorded while the participants performed balance tasks during ovulation and menstruation. Significantly greater posture sway characteristics and ankle muscle elasticity were found during ovulation than during menstruation; lower tone and stiffness of the ankle muscles were observed at ovulation (p connective tissues. We therefore postulate that estrogen increases joint and muscle laxity and affects posture stability according to the phase of the menstrual cycle.

Increased sphingosine-1-phosphate improves muscle regeneration in acutely injured mdx mice

Science.gov (United States)

2013-01-01

Background Presently, there is no effective treatment for the lethal muscle wasting disease Duchenne muscular dystrophy (DMD). Here we show that increased sphingosine-1-phoshate (S1P) through direct injection or via the administration of the small molecule 2-acetyl-4(5)-tetrahydroxybutyl imidazole (THI), an S1P lyase inhibitor, has beneficial effects in acutely injured dystrophic muscles of mdx mice. Methods We treated mdx mice with and without acute injury and characterized the histopathological and functional effects of increasing S1P levels. We also tested exogenous and direct administration of S1P on mdx muscles to examine the molecular pathways under which S1P promotes regeneration in dystrophic muscles. Results Short-term treatment with THI significantly increased muscle fiber size and extensor digitorum longus (EDL) muscle specific force in acutely injured mdx limb muscles. In addition, the accumulation of fibrosis and fat deposition, hallmarks of DMD pathology and impaired muscle regeneration, were lower in the injured muscles of THI-treated mdx mice. Furthermore, increased muscle force was observed in uninjured EDL muscles with a longer-term treatment of THI. Such regenerative effects were linked to the response of myogenic cells, since intramuscular injection of S1P increased the number of Myf5nlacz/+ positive myogenic cells and newly regenerated myofibers in injured mdx muscles. Intramuscular injection of biotinylated-S1P localized to muscle fibers, including newly regenerated fibers, which also stained positive for S1P receptor 1 (S1PR1). Importantly, plasma membrane and perinuclear localization of phosphorylated S1PR1 was observed in regenerating muscle fibers of mdx muscles. Intramuscular increases of S1P levels, S1PR1 and phosphorylated ribosomal protein S6 (P-rpS6), and elevated EDL muscle specific force, suggest S1P promoted the upregulation of anabolic pathways that mediate skeletal muscle mass and function. Conclusions These data show that S1P is

Increased response to insulin of glucose metabolism in the 6-day unloaded rat soleus muscle

Science.gov (United States)

Henriksen, Erik J.; Tischler, Marc E.; Johnson, David G.

1986-01-01

Hind leg muscles of female rats were unloaded by tail cast suspension for 6 days. In the fresh-frozen unloaded soleus, the significantly greater concentration of glycogen correlated with a lower activity ratio of glycogen phosphorylase (p less than 0.02). The activity ratio of glycogen synthase also was lower (p less than 0.001), possibly due to the higher concentration of glycogen. In isolated unloaded soleus, insulin (0.1 milliunit/ml) increased the oxidation of D(U-C-14) glucose, release of lactate and pyruvate, incorporation of D-(U-C-14) glucose into glycogen, and the concentration of glucose 6-phosphate more (p less than 0.05) than in the weight-bearing soleus. At physiological doses of insulin, the percent of maximal uptake of 2-deoxy-D-(1,2-H-3) glucose/muscle also was greater in the unloaded soleus. Unloading of the soleus increased, by 50 percent the concentration of insuling receptors, due to no decrease in total receptor number during muscle atrophy. This increase may account for the greater response of glucose metabolism to insulin in this muscle. The extensor digitorum longus, which generally shows little response to unloading, displayed no differential response of glucose metabolism to insulin.

Step Cut Lengthening: A Technique for Treatment of Flexor Pollicis Longus Tendon Rupture.

Science.gov (United States)

Chong, Chew-Wei; Chen, Shih-Heng

2018-04-01

Reconstruction of a tendon defect is a challenging task in hand surgery. Delayed repair of a ruptured flexor pollicis longus (FPL) tendon is often associated with tendon defect. Primary repair of the tendon is often not possible, particularly after debridement of the unhealthy segment of the tendon. As such, various surgical treatments have been described in the literature, including single-stage tendon grafting, 2-stage tendon grafting, flexor digitorum superficialis tendon transfer from ring finger, and interphalangeal joint arthrodesis. We describe step cut lengthening of FPL tendon for the reconstruction of FPL rupture. This is a single-stage reconstruction without the need for tendon grafting or tendon transfer. To our knowledge, no such technique has been previously described.

Silicone infusion tubing instead of Hunter rods for two-stage zone 2 flexor tendon reconstruction in a resource-limited surgical environment.

Science.gov (United States)

Kibadi, K; Moutet, F

2017-10-01

The authors describe their experience using silicone infusion tubing in place of Hunter rods for two-stage zone 2 flexor tendon reconstruction in a resource-limited surgical environment. This case report features a 47-year-old, right-handed man who had no active PIP and DIP joint flexion in four fingers of the right hand 5 months after an injury. During the first repair stage, the A2 and A4 pulleys were reconstructed using an extensor retinaculum graft. An infusion tube was inserted instead of Hunter rods. During the second stage, formation of a digital neo-canal around the infusion tubing was observed. The infusion tubing was removed and replaced with a palmaris longus tendon graft according to the conventional technique. Physiotherapy and rehabilitation followed surgery. At 6 months, very significant progress had been made with complete recovery of PIP and DIP flexion in the four fingers. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study.

Science.gov (United States)

Kataoka, T; Moritomo, H; Omokawa, S; Iida, A; Wada, T; Aoki, M

2013-06-01

We developed a new triangular fibrocartilage complex reconstruction technique for distal radioulnar joint instability in which the palmar portion of the triangular fibrocartilage complex was predominantly reconstructed, and evaluated whether such reconstruction can restore stability of the distal radioulnar joint in seven fresh cadaver upper extremities. Distal radioulnar joint instability was induced by cutting all soft-tissue stabilizers around the distal ulna. Using a palmar approach, a palmaris longus tendon graft was sutured to the remnant of the palmar radioulnar and ulnocarpal ligaments. The graft was then passed through a bone tunnel created at the fovea and was sutured. Loads were applied to the radius, and dorsopalmar displacements of the radius relative to the ulna were measured using an electromagnetic tracking device in neutral rotation, 60° supination and 60° pronation. We compared the dorsopalmar displacements before sectioning, before reconstruction and after reconstruction. Dorsopalmar instability produced by sectioning significantly improved in all forearm positions after reconstruction.

Overload-induced skeletal muscle hypertrophy is not impaired in STZ-diabetic rats

Science.gov (United States)

Fortes, Marco Aurélio S; Pinheiro, Carlos Hermano J; Guimarães-Ferreira, Lucas; Vitzel, Kaio F; Vasconcelos, Diogo A A; Curi, Rui

2015-01-01

The aim of this study was to evaluate the effect of overload-induced hypertrophy on extensor digitorum longus (EDL) and soleus muscles of streptozotocin-induced diabetic rats. The overload-induced hypertrophy and absolute tetanic and twitch forces increases in EDL and soleus muscles were not different between diabetic and control rats. Phospho-Akt and rpS6 contents were increased in EDL muscle after 7 days of overload and returned to the pre-overload values after 30 days. In the soleus muscle, the contents of total and phospho-Akt and total rpS6 were increased in both groups after 7 days. The contents of total Akt in controls and total rpS6 and phospho-Akt in the diabetic rats remained increased after 30 days. mRNA expression after 7 days of overload in the EDL muscle of control and diabetic animals showed an increase in MGF and follistatin and a decrease in myostatin and Axin2. The expression of FAK was increased and of MuRF-1 and atrogin-1 decreased only in the control group, whereas Ankrd2 expression was enhanced only in diabetic rats. In the soleus muscle caused similar changes in both groups: increase in FAK and MGF and decrease in Wnt7a, MuRF-1, atrogin-1, and myostatin. Differences between groups were observed only in the increased expression of follistatin in diabetic animals and decreased Ankrd2 expression in the control group. So, insulin deficiency does not impair the overload-induced hypertrophic response in soleus and EDL muscles. However, different mechanisms seem to be involved in the comparable hypertrophic responses of skeletal muscle in control and diabetic animals. PMID:26197932

Structural characterization of CFA/III and Longus type IVb pili from enterotoxigenic Escherichia coli.

Science.gov (United States)

Kolappan, Subramaniapillai; Roos, Justin; Yuen, Alex S W; Pierce, Owen M; Craig, Lisa

2012-05-01

The type IV pili are helical filaments found on many Gram-negative pathogenic bacteria, with multiple diverse roles in pathogenesis, including microcolony formation, adhesion, and twitching motility. Many pathogenic enterotoxigenic Escherichia coli (ETEC) isolates express one of two type IV pili belonging to the type IVb subclass: CFA/III or Longus. Here we show a direct correlation between CFA/III expression and ETEC aggregation, suggesting that these pili, like the Vibrio cholerae toxin-coregulated pili (TCP), mediate microcolony formation. We report a 1.26-Å resolution crystal structure of CofA, the major pilin subunit from CFA/III. CofA is very similar in structure to V. cholerae TcpA but possesses a 10-amino-acid insertion that replaces part of the α2-helix with an irregular loop containing a 3(10)-helix. Homology modeling suggests a very similar structure for the Longus LngA pilin. A model for the CFA/III pilus filament was generated using the TCP electron microscopy reconstruction as a template. The unique 3(10)-helix insert fits perfectly within the gap between CofA globular domains. This insert, together with differences in surface-exposed residues, produces a filament that is smoother and more negatively charged than TCP. To explore the specificity of the type IV pilus assembly apparatus, CofA was expressed heterologously in V. cholerae by replacing the tcpA gene with that of cofA within the tcp operon. Although CofA was synthesized and processed by V. cholerae, no CFA/III filaments were detected, suggesting that the components of the type IVb pilus assembly system are highly specific to their pilin substrates.

Isolated Tuberculous Tenosynovitis of the Anterior Tibial and Extensor Digitorum Longus Tendons

Directory of Open Access Journals (Sweden)

Berhan Genç

2013-01-01

Full Text Available Musculoskeletal system is involved in 1-5% of extrapulmonary cases of tuberculosis. Tuberculous tenosynovitis is a rare form of musculoskeletal tuberculosis. Tuberculosis of the tendon sheath in the hand has been seen in a few cases. Involvement of the tendons of the leg is less common. Diagnosis is not easy as there are no specific clinical symptoms or signs. A 33-year-old male presented with painful swelling in the distal right lower limb that caused restriction of movement. Imaging studies showed inflammation and infection of the extensor digitorium longus and tibialis anterior tendons. Histopathological studies showed a necrotizing granulomatous inflammation in the synovial tissue. A diagnosis of tuberculosis was made and medical treatment was initiated that proved successful. Patient remained infection-free at 26-month follow-up examination.

Studies on the possible role of thyroid hormone in altered muscle protein turnover during sepsis

International Nuclear Information System (INIS)

Hasselgren, P.O.; Chen, I.W.; James, J.H.; Sperling, M.; Warner, B.W.; Fischer, J.E.

1987-01-01

Five days after thyroidectomy (Tx) or sham-Tx in young male Sprague-Dawley rats, sepsis was induced by cecal ligation and puncture (CLP). Control animals underwent laparotomy and manipulation of the cecum without ligation or puncture. Sixteen hours after CLP or laparotomy, protein synthesis and degradation were measured in incubated extensor digitorum longus (EDL) and soleus (SOL) muscles by determining rate of 14 C-phenylalanine incorporation into protein and tyrosine release into incubation medium, respectively. Triiodothyronine (T3) was measured in serum and muscle tissue. Protein synthesis was reduced by 39% and 22% in EDL and SOL, respectively, 16 hours after CLP in sham-Tx rats. The response to sepsis of protein synthesis was abolished in Tx rats. Protein breakdown was increased by 113% and 68% in EDL and SOL, respectively, 16 hours after CLP in sham-Tx animals. The increase in muscle proteolysis during sepsis was blunted in hypothyroid animals and was 42% and 49% in EDL and SOL, respectively. T3 in serum was reduced by sepsis, both in Tx and sham-Tx rats. T3 in muscle, however, was maintained or increased during sepsis. Abolished or blunted response of muscle protein turnover after CLP in hypothyroid animals may reflect a role of thyroid hormones in altered muscle protein metabolism during sepsis. Reduced serum levels of T3, but maintained or increased muscle concentrations of the hormone, suggests that increased T3 uptake by muscle may be one mechanism of low T3 syndrome in sepsis, further supporting the concept of a role for thyroid hormone in metabolic alterations in muscle during sepsis

Multi-slice MRI reveals heterogeneity in disease distribution along the length of muscle in Duchenne muscular dystrophy.

Science.gov (United States)

Chrzanowski, Stephen M; Baligand, Celine; Willcocks, Rebecca J; Deol, Jasjit; Schmalfuss, Ilona; Lott, Donovan J; Daniels, Michael J; Senesac, Claudia; Walter, Glenn A; Vandenborne, Krista

2017-09-01

Duchenne muscular dystrophy (DMD) causes progressive pathologic changes to muscle secondary to a cascade of inflammation, lipid deposition, and fibrosis. Clinically, this manifests as progressive weakness, functional loss, and premature mortality. Though insult to whole muscle groups is well established, less is known about the relationship between intramuscular pathology and function. Differences of intramuscular heterogeneity across muscle length were assessed using an ordinal MRI grading scale in lower leg muscles of boys with DMD and correlated to patient's functional status. Cross sectional T 1 weighted MRI images with fat suppression were obtained from ambulatory boys with DMD. Six muscles (tibialis anterior, extensor digitorum longus, peroneus, soleus, medial and lateral gastrocnemii) were graded using an ordinal grading scale over 5 slice sections along the lower leg length. The scores from each slice were combined and results were compared to global motor function and age. Statistically greater differences of involvement were observed at the proximal ends of muscle compared to the midbellies. Multi-slice assessment correlated significantly to age and the Vignos functional scale, whereas single-slice assessment correlated to the Vignos functional scale only. Lastly, differential disease involvement of whole muscle groups and intramuscular heterogeneity were observed amongst similar age subjects. A multi-slice ordinal MRI grading scale revealed that muscles are not uniformly affected, with more advanced disease visible near the tendons in a primarily ambulatory population with DMD. A geographically comprehensive evaluation of the heterogeneously affected muscle in boys with DMD may more accurately assess disease involvement.

Muscle activation in young men during a lower limb aquatic resistance exercise with different devices.

Science.gov (United States)

Borreani, Sebastien; Colado, Juan Carlos; Furio, Josep; Martin, Fernando; Tella, Víctor

2014-05-01

Little research has been reported on the effects of using different devices with resistance exercises in a water environment. This study compared muscular activation of lower extremity and core muscles during leg adduction performed at maximum velocity with drag and floating devices of different sizes. A total of 24 young men (mean age 23.20 ± 1.18 years) performed 3 repetitions of leg adduction at maximum velocity using 4 different devices (ie, large/small and drag/floating). The maximum amplitude of the electromyographic root mean square of the adductor longus, rectus abdominis, external oblique on the dominant side, external oblique on the nondominant side, and erector lumbar spinae were recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Unexpectedly, no significant (P > 0.05) differences were found in the neuromuscular responses among the different devices used; the average activation of agonist muscle adequate for neuromuscular conditioning was 40.95% of MVIC. In addition, external oblique activation is greater on the contralateral side to stabilize the body (average, 151.74%; P < 0.05). Therefore, if maximum muscle activation is required, the kind of device is not relevant. Thus, the choice should be based on economic factors.

Comparison of myosin heavy chain mRNAs, protein isoforms and fiber type proportions in the rat slow and fast muscles

Czech Academy of Sciences Publication Activity Database

Žurmanová, J.; Soukup, Tomáš

2013-01-01

Roč. 62, č. 4 (2013), s. 445-453 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/08/0256; GA ČR(CZ) GA305/09/1228; GA MŠk(CZ) 7AMB12SK158; GA MŠk(CZ) LH12058 Grant - others:EC(XE) LSH-CT-2004-511978 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : rat * soleus * extensor digitorum longus * myosin heavy chain isoforms * muscle gene expression * quantitative Real Time RT-PCR * SDS - PAGE * fiber type analysis Subject RIV: EA - Cell Biology Impact factor: 1.487, year: 2013

Rigor force responses of permeabilized fibres from fast and slow skeletal muscles of aged rats.

Science.gov (United States)

Plant, D R; Lynch, G S

2001-09-01

1. Ageing is generally associated with a decline in skeletal muscle mass and strength and a slowing of muscle contraction, factors that impact upon the quality of life for the elderly. The mechanisms underlying this age-related muscle weakness have not been fully resolved. The purpose of the present study was to determine whether the decrease in muscle force as a consequence of age could be attributed partly to a decrease in the number of cross-bridges participating during contraction. 2. Given that the rigor force is proportional to the approximate total number of interacting sites between the actin and myosin filaments, we tested the null hypothesis that the rigor force of permeabilized muscle fibres from young and old rats would not be different. 3. Permeabilized fibres from the extensor digitorum longus (fast-twitch; EDL) and soleus (predominantly slow-twitch) muscles of young (6 months of age) and old (27 months of age) male F344 rats were activated in Ca2+-buffered solutions to determine force-pCa characteristics (where pCa = -log(10)[Ca2+]) and then in solutions lacking ATP and Ca2+ to determine rigor force levels. 4. The rigor forces for EDL and soleus muscle fibres were not different between young and old rats, indicating that the approximate total number of cross-bridges that can be formed between filaments did not decline with age. We conclude that the age-related decrease in force output is more likely attributed to a decrease in the force per cross-bridge and/or decreases in the efficiency of excitation-contraction coupling.

IGF-I treatment improves the functional properties of fast- and slow-twitch skeletal muscles from dystrophic mice.

Science.gov (United States)

Lynch, G S; Cuffe, S A; Plant, D R; Gregorevic, P

2001-04-01

Although insulin-like growth factor-I (IGF-I) has been proposed for use by patients suffering from muscle wasting conditions, few studies have investigated the functional properties of dystrophic skeletal muscle following IGF-I treatment. 129P1 ReJ-Lama2(dy) (129 ReJ dy/dy) dystrophic mice suffer from a deficiency in the structural protein, laminin, and exhibit severe muscle wasting and weakness. We tested the hypothesis that 4 weeks of IGF-I treatment ( approximately 2 mg/kg body mass, 50 g/h via mini-osmotic pump, subcutaneously) would increase the mass and force producing capacity of skeletal muscles from dystrophic mice. IGF-I treatment increased the mass of the extensor digitorum longus (EDL) and soleus muscles of dystrophic mice by 20 and 29%, respectively, compared with untreated dystrophic mice (administered saline-vehicle only). Absolute maximum force (P(o)) of the EDL and soleus muscle was increased by 40 and 32%, respectively, following IGF-I treatment. Specific P(o) (sP(o)) was increased by 23% in the EDL muscles of treated compared with untreated mice, but in the soleus muscle sP(o) was unchanged. IGF-I treatment increased the proportion of type IIB and type IIA fibres and decreased the proportion of type I fibres in the EDL muscles of dystrophic mice. In the soleus muscles of dystrophic mice, IGF-I treatment increased the proportion of type IIA fibres and decreased the proportion of type I fibres. Average fibre cross-sectional area was increased in the EDL and soleus muscles of treated compared with untreated mice. We conclude that IGF-I treatment ameliorates muscle wasting and improves the functional properties of skeletal muscles of dystrophic mice. The findings have important implications for the role of IGF-I in ameliorating muscle wasting associated with the muscular dystrophies.

Skeletal muscle glucose uptake during contraction is regulated by nitric oxide and ROS independently of AMPK.

Science.gov (United States)

Merry, Troy L; Steinberg, Gregory R; Lynch, Gordon S; McConell, Glenn K

2010-03-01

Reactive oxygen species (ROS) and nitric oxide (NO) have been implicated in the regulation of skeletal muscle glucose uptake during contraction, and there is evidence that they do so via interaction with AMP-activated protein kinase (AMPK). In this study, we tested the hypothesis that ROS and NO regulate skeletal muscle glucose uptake during contraction via an AMPK-independent mechanism. Isolated extensor digitorum longus (EDL) and soleus muscles from mice that expressed a muscle-specific kinase dead AMPKalpha2 isoform (AMPK-KD) and wild-type litter mates (WT) were stimulated to contract, and glucose uptake was measured in the presence or absence of the antioxidant N-acetyl-l-cysteine (NAC) or the nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-l-arginine (l-NMMA). Contraction increased AMPKalpha2 activity in WT but not AMPK-KD EDL muscles. However, contraction increased glucose uptake in the EDL and soleus muscles of AMPK-KD and WT mice to a similar extent. In EDL muscles, NAC and l-NMMA prevented contraction-stimulated increases in oxidant levels (dichloroflourescein fluorescence) and NOS activity, respectively, and attenuated contraction-stimulated glucose uptake in both genotypes to a similar extent. In soleus muscles of AMPK-KD and WT mice, NAC prevented contraction-stimulated glucose uptake and l-NMMA had no effect. This is likely attributed to the relative lack of neuronal NOS in the soleus muscles compared with EDL muscles. Contraction increased AMPKalpha Thr(172) phosphorylation in EDL and soleus muscles of WT but not AMPK-KD mice, and this was not affected by NAC or l-NMMA treatment. In conclusion, ROS and NO are involved in regulating skeletal muscle glucose uptake during contraction via an AMPK-independent mechanism.

Protein metabolism in slow- and fast-twitch skeletal muscle during turpentine-induced inflammation.

Science.gov (United States)

Muthny, Tomas; Kovarik, Miroslav; Sispera, Ludek; Tilser, Ivan; Holecek, Milan

2008-02-01

The aim of our study was to evaluate the differences in protein and amino acid metabolism after subcutaneous turpentine administration in the soleus muscle (SOL), predominantly composed of red fibres, and the extensor digitorum longus muscle (EDL) composed of white fibres. Young rats (40-60 g) were injected subcutaneously with 0.2 ml of turpentine oil/100 g body weight (inflammation) or with the same volume of saline solution (control). Twenty-four hours later SOL and EDL were dissected and incubated in modified Krebs-Heinseleit buffer to estimate total and myofibrillar proteolysis, chymotrypsin-like activity of proteasome (CHTLA), leucine oxidation, protein synthesis and amino acid release into the medium. The data obtained demonstrate that in intact rats, all parameters measured except protein synthesis are significantly higher in SOL than in EDL. In turpentine treated animals, CHTLA increased and protein synthesis decreased significantly more in EDL. Release of leucine was inhibited significantly more in SOL. We conclude that turpentine-induced inflammation affects more CHTLA, protein synthesis and leucine release in EDL compared to SOL.

A Reduction in Selenoprotein S Amplifies the Inflammatory Profile of Fast-Twitch Skeletal Muscle in the mdx Dystrophic Mouse

Directory of Open Access Journals (Sweden)

Craig Robert Wright

2017-01-01

Full Text Available Excessive inflammation is a hallmark of muscle myopathies, including Duchenne muscular dystrophy (DMD. There is interest in characterising novel genes that regulate inflammation due to their potential to modify disease progression. Gene polymorphisms in Selenoprotein S (Seps1 are associated with elevated proinflammatory cytokines, and in vitro SEPS1 is protective against inflammatory stress. Given that SEPS1 is highly expressed in skeletal muscle, we investigated whether the genetic reduction of Seps1 exacerbated inflammation in the mdx mouse. F1 male mdx mice with a heterozygous Seps1 deletion (mdx:Seps1−/+ were generated. The mdx:Seps1−/+ mice had a 50% reduction in SEPS1 protein expression in hindlimb muscles. In the extensor digitorum longus (EDL muscles, mRNA expression of monocyte chemoattractant protein 1 (Mcp-1 (P=0.034, macrophage marker F4/80 (P=0.030, and transforming growth factor-β1 (Tgf-β1 (P=0.056 were increased in mdx:Seps1−/+ mice. This was associated with a reduction in muscle fibre size; however, ex vivo EDL muscle strength and endurance were unaltered. In dystrophic slow twitch soleus muscles, SEPS1 reduction had no effect on the inflammatory profile nor function. In conclusion, the genetic reduction of Seps1 appears to specifically exacerbate the inflammatory profile of fast-twitch muscle fibres, which are typically more vulnerable to degeneration in dystrophy.

Incubating Isolated Mouse EDL Muscles with Creatine Improves Force Production and Twitch Kinetics in Fatigue Due to Reduction in Ionic Strength

Science.gov (United States)

Head, Stewart I.; Greenaway, Bronwen; Chan, Stephen

2011-01-01

Background Creatine supplementation can improve performance during high intensity exercise in humans and improve muscle strength in certain myopathies. In this present study, we investigated the direct effects of acute creatine incubation on isolated mouse fast-twitch EDL muscles, and examined how these effects change with fatigue. Methods and Results The extensor digitorum longus muscle from mice aged 12–14 weeks was isolated and stimulated with field electrodes to measure force characteristics in 3 different states: (i) before fatigue; (ii) immediately after a fatigue protocol; and (iii) after recovery. These served as the control measurements for the muscle. The muscle was then incubated in a creatine solution and washed. The measurement of force characteristics in the 3 different states was then repeated. In un-fatigued muscle, creatine incubation increased the maximal tetanic force. In fatigued muscle, creatine treatment increased the force produced at all frequencies of stimulation. Incubation also increased the rate of twitch relaxation and twitch contraction in fatigued muscle. During repetitive fatiguing stimulation, creatine-treated muscles took 55.1±9.5% longer than control muscles to lose half of their original force. Measurement of weight changes showed that creatine incubation increased EDL muscle mass by 7%. Conclusion Acute creatine application improves force production in isolated fast-twitch EDL muscle, and these improvements are particularly apparent when the muscle is fatigued. One likely mechanism for this improvement is an increase in Ca2+ sensitivity of contractile proteins as a result of ionic strength decreases following creatine incubation. PMID:21850234

Incubating isolated mouse EDL muscles with creatine improves force production and twitch kinetics in fatigue due to reduction in ionic strength.

Directory of Open Access Journals (Sweden)

Stewart I Head

Full Text Available BACKGROUND: Creatine supplementation can improve performance during high intensity exercise in humans and improve muscle strength in certain myopathies. In this present study, we investigated the direct effects of acute creatine incubation on isolated mouse fast-twitch EDL muscles, and examined how these effects change with fatigue. METHODS AND RESULTS: The extensor digitorum longus muscle from mice aged 12-14 weeks was isolated and stimulated with field electrodes to measure force characteristics in 3 different states: (i before fatigue; (ii immediately after a fatigue protocol; and (iii after recovery. These served as the control measurements for the muscle. The muscle was then incubated in a creatine solution and washed. The measurement of force characteristics in the 3 different states was then repeated. In un-fatigued muscle, creatine incubation increased the maximal tetanic force. In fatigued muscle, creatine treatment increased the force produced at all frequencies of stimulation. Incubation also increased the rate of twitch relaxation and twitch contraction in fatigued muscle. During repetitive fatiguing stimulation, creatine-treated muscles took 55.1±9.5% longer than control muscles to lose half of their original force. Measurement of weight changes showed that creatine incubation increased EDL muscle mass by 7%. CONCLUSION: Acute creatine application improves force production in isolated fast-twitch EDL muscle, and these improvements are particularly apparent when the muscle is fatigued. One likely mechanism for this improvement is an increase in Ca(2+ sensitivity of contractile proteins as a result of ionic strength decreases following creatine incubation.

A bio-robotic platform for integrating internal and external mechanics during muscle-powered swimming.

Science.gov (United States)

Richards, Christopher T; Clemente, Christofer J

2012-03-01

To explore the interplay between muscle function and propulsor shape in swimming animals, we built a robotic foot to mimic the morphology and hind limb kinematics of Xenopus laevis frogs. Four foot shapes ranging from low aspect ratio (AR = 0.74) to high (AR = 5) were compared to test whether low-AR feet produce higher propulsive drag force resulting in faster swimming. Using feedback loops, two complementary control modes were used to rotate the foot: force was transmitted to the foot either from (1) a living plantaris longus (PL) muscle stimulated in vitro or (2) an in silico mathematical model of the PL. To mimic forward swimming, foot translation was calculated in real time from fluid force measured at the foot. Therefore, bio-robot swimming emerged from muscle-fluid interactions via the feedback loop. Among in vitro-robotic trials, muscle impulse ranged from 0.12 ± 0.002 to 0.18 ± 0.007 N s and swimming velocities from 0.41 ± 0.01 to 0.43 ± 0.00 m s(-1), similar to in vivo values from prior studies. Trends in in silico-robotic data mirrored in vitro-robotic observations. Increasing AR caused a small (∼10%) increase in peak bio-robot swimming velocity. In contrast, muscle force-velocity effects were strongly dependent on foot shape. Between low- and high-AR feet, muscle impulse increased ∼50%, while peak shortening velocity decreased ∼50% resulting in a ∼20% increase in net work. However, muscle-propulsion efficiency (body center of mass work/muscle work) remained independent of AR. Thus, we demonstrate how our experimental technique is useful for quantifying the complex interplay among limb morphology, muscle mechanics and hydrodynamics.

Expression of Dihydropyridine and Ryanodine Receptors in Type IIA Fibers of Rat Skeletal Muscle

International Nuclear Information System (INIS)

Anttila, Katja; Mänttäri, Satu; Järvilehto, Matti

2007-01-01

In this study, the fiber type specificity of dihydropyridine receptors (DHPRs) and ryanodine receptors (RyRs) in different rat limb muscles was investigated. Western blot and histochemical analyses provided for the first time evidence that the expression of both receptors correlates to a specific myosin heavy chain (MHC) composition. We observed a significant (p=0.01) correlation between DHP as well as Ry receptor density and the expression of MHC IIa (correlation factor r=0.674 and r=0.645, respectively) in one slow-twitch, postural muscle (m. soleus), one mixed, fast-twitch muscle (m. gastrocnemius) and two fast-twitch muscles (m. rectus femoris, m. extensor digitorum longus). The highest DHP and Ry receptor density was found in the white part of m. rectus femoris (0.058±0.0060 and 0.057±0.0158 ODu, respectively). As expected, the highest relative percentage of MHC IIa was also found in the white part of m. rectus femoris (70.0±7.77%). Furthermore, histochemical experiments revealed that the IIA fibers stained most strongly for the fluorophore-conjugated receptor blockers. Our data clearly suggest that the expression of DHPRs and RyRs follows a fiber type-specific pattern, indicating an important role for these proteins in the maintenance of an effective Ca 2+ cycle in the fast contracting fiber type IIA

Attritional rupture of extensor pollicis longus: a rare complication following elastic stable intramedullary nailing of a paediatric radial fracture.

LENUS (Irish Health Repository)

Sproule, James A

2011-01-01

Elastic stable intramedullary nail fixation has become established as an acceptable method of treatment for diaphyseal fractures of both forearm bones in the paediatric population. It is considered safe, minimally invasive and does not compromise physeal growth. We report a case of delayed rupture of extensor pollicis longus due to attrition over the sharp edges of a protruding nail end after elastic stable intramedullary nailing of a paediatric radial diaphyseal fracture.

Differential response of early and late phases of skeletal muscle regeneration to exogenous supply of testosterone and insulin

International Nuclear Information System (INIS)

Qazi, I.; Riaz, S.

2005-01-01

Effect of insulin and testosterone, separately and in combination on the regeneration of skeletal fibres within intact extensor digitorum longus (EDL) muscle grafts was studied in mice. It was found that intraperitoneal supply of 2 mg/100 g body weight/day of testosterone accelerated skeletal muscle regeneration within ten days of grafting. The regenerated muscle fibres in such grafts attained significantly higher % recovery of average cross-sectional area (ACSA) than in the controls grafts. Later on, provision of the hormone did not further promote growth of the regenerated muscle fibres. In the insulin-supplemented animals (2 units/100 g body weight/day) the grafts showed hyperplasia and atrophy of the regenerating muscle fibres during the first and the last study periods, respectively. Histological and morphometric analysis of 20-day old EDL muscle regenerates that were supplied with either insulin or testosterone during the first 10-days of transplantation followed by hormone administration in reverse sequence revealed valuable differences. Supply of testosterone and then insulin escalated the process of regeneration and growth so that the ACSA of the regenerated muscle fibres in such grafts turned out to be significantly higher that in the corresponding stages of control, or when only insulin and only testosterone were administered. Reverse sequence of the administration of the hormones exerted negative effects and the regenerated muscle fibres showed various levels of atrophy. These results indicate the importance of identification of particular phases of the process of skeletal muscle regeneration that may be more responsive to anabolic agents. Proper sequence of administration of the hormones to promote the regeneration of skeletal muscle fibres in whole EDL muscle autotransplants is also explained. (author)

Cancer cachexia decreases specific force and accelerates fatigue in limb muscle

Energy Technology Data Exchange (ETDEWEB)

Roberts, B. M. [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States); Frye, G. S.; Ahn, B.; Ferreira, L. F. [1864 Stadium Road, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32610 (United States); Judge, A.R., E-mail: arjudge@phhp.ufl.edu [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States)

2013-06-07

Highlights: •C-26 cancer cachexia causes a significant decrease in limb muscle absolute force. •C-26 cancer cachexia causes a significant decrease in limb muscle specific force. •C-26 cancer cachexia decreases fatigue resistance in the soleus muscle. •C-26 cancer cachexia prolongs time to peak twitch tension in limb muscle. •C-26 cancer cachexia prolongs one half twitch relaxation time in limb muscle. -- Abstract: Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative

Cancer cachexia decreases specific force and accelerates fatigue in limb muscle

International Nuclear Information System (INIS)

Roberts, B.M.; Frye, G.S.; Ahn, B.; Ferreira, L.F.; Judge, A.R.

2013-01-01

Highlights: •C-26 cancer cachexia causes a significant decrease in limb muscle absolute force. •C-26 cancer cachexia causes a significant decrease in limb muscle specific force. •C-26 cancer cachexia decreases fatigue resistance in the soleus muscle. •C-26 cancer cachexia prolongs time to peak twitch tension in limb muscle. •C-26 cancer cachexia prolongs one half twitch relaxation time in limb muscle. -- Abstract: Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative

EMG activity of hip and trunk muscles during deep-water running.

Science.gov (United States)

Kaneda, Koichi; Sato, Daisuke; Wakabayashi, Hitoshi; Nomura, Takeo

2009-12-01

The present study used synchronized motion analysis to investigate the activity of hip and trunk muscles during deep-water running (DWR) relative to land walking (LW) and water walking (WW). Nine healthy men performed each exercise at self-determined slow, moderate, and fast paces, and surface electromyography was used to investigate activity of the adductor longus, gluteus maxima, gluteus medius, rectus abdominis, oblique externus abdominis, and erector spinae. The following kinematic parameters were calculated: the duration of one cycle, range of motion (ROM) of the hip joint, and absolute angles of the pelvis and trunk with respect to the vertical axis in the sagittal plane. The percentages of maximal voluntary contraction (%MVC) of each muscle were higher during DWR than during LW and WW. The %MVC of the erector spinae during WW increased concomitant with the pace increment. The hip joint ROMs were larger in DWR than in LW and WW. Forward inclinations of the trunk were apparent for DWR and fast-paced WW. The pelvis was inclined forward in DWR and WW. In conclusion, the higher-level activities during DWR are affected by greater hip joint motion and body inclinations with an unstable floating situation.

Flexor pollicis longus repair in a patient with Linburg-Comstock anomaly: A case report

Directory of Open Access Journals (Sweden)

Mehmet Unal

2016-08-01

Results: At the end of the rehabilitation program, the thumb recovered full range of motion, and physical examination revealed synchronous flexion movement (synkinesis of the thumb and index finger. Conclusion: Flexor pollicis longus tendon lacerations are common in the clinical practice of hand surgeons. Making a separate proximal wrist incision is a very useful technique to reach a proximal tendon stump. Otherwise, aggressive maneuvers may cause additional damage to the tendons involved and result in unpredicted outcomes. The attempts to retrieve the tendon at the injury site resulted in failure and gave a tethering sensation to the surgeon who recalled the Linburg-Comstock anomaly. [Hand Microsurg 2016; 5(2.000: 88-91

The effect of different exercise programs on cervical flexor muscles dimensions in patients with chronic neck pain.

Science.gov (United States)

Javanshir, Khodabakhsh; Amiri, Mohsen; Mohseni Bandpei, Mohammad Ali; De las Penas, Cesar Fernandez; Rezasoltani, Asghar

2015-01-01

The effect of different exercise programs on cervical flexor muscles dimensions in patients with chronic neck pain is yet to be demonstrated. The purpose of this study was to assess the effect of two exercise programs; craniocervical flexion (CCF) and cervical flexion (CF), on flexor muscles dimensions in patients with chronic neck pain. Following ethical approval, 60 patients were randomly assigned into either a CCF group or a CF group. Patients in the CCF group were given CCF exercises and those in the CF group received CF exercises. All patients received interventions for a period of ten weeks. Pain intensity and functional disability were assessed using numerical pain rate scale and neck disability index, respectively. Dimensions of longus colli (LC) and sternoclidomastoid (SCM) muscles were measured using ultrasonography (US). All measurements were taken before and after interventions. Following intervention, the CCF group demonstrated a significant increase in LC muscle dimensions including cross sectional area, width and thickness compared with the CF group. A statistically significant increase was found on SCM thickness in the CF group. Following intervention, SCM thickness measurement in the CCF group showed no significant changes. Statistically significant decrease on pain intensity and disability were also found in both groups. Present findings demonstrated that craniocervical flexion program which specifically recruiting deep cervical flexor muscles increased LC muscle dimension significantly and CF program as an endurance training program increased SCM thickness.

Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults.

Science.gov (United States)

Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

2016-09-01

Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24±2 y) and 20 older adults (73±6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002adults for the trunk (0.001older adults for the ankle (0.009Older adults had higher electrophysiological costs for all stance conditions. Muscle coordination showed inverse activity patterns at the ankle and trunk. Optimal balance and strength training programs should take into account age-specific alterations in muscle activity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A bio-robotic platform for integrating internal and external mechanics during muscle-powered swimming

International Nuclear Information System (INIS)

Richards, Christopher T; Clemente, Christofer J

2012-01-01

To explore the interplay between muscle function and propulsor shape in swimming animals, we built a robotic foot to mimic the morphology and hind limb kinematics of Xenopus laevis frogs. Four foot shapes ranging from low aspect ratio (AR = 0.74) to high (AR = 5) were compared to test whether low-AR feet produce higher propulsive drag force resulting in faster swimming. Using feedback loops, two complementary control modes were used to rotate the foot: force was transmitted to the foot either from (1) a living plantaris longus (PL) muscle stimulated in vitro or (2) an in silico mathematical model of the PL. To mimic forward swimming, foot translation was calculated in real time from fluid force measured at the foot. Therefore, bio-robot swimming emerged from muscle–fluid interactions via the feedback loop. Among in vitro-robotic trials, muscle impulse ranged from 0.12 ± 0.002 to 0.18 ± 0.007 N s and swimming velocities from 0.41 ± 0.01 to 0.43 ± 0.00 m s −1 , similar to in vivo values from prior studies. Trends in in silico-robotic data mirrored in vitro-robotic observations. Increasing AR caused a small (∼10%) increase in peak bio-robot swimming velocity. In contrast, muscle force–velocity effects were strongly dependent on foot shape. Between low- and high-AR feet, muscle impulse increased ∼50%, while peak shortening velocity decreased ∼50% resulting in a ∼20% increase in net work. However, muscle-propulsion efficiency (body center of mass work/muscle work) remained independent of AR. Thus, we demonstrate how our experimental technique is useful for quantifying the complex interplay among limb morphology, muscle mechanics and hydrodynamics. (paper)

Flexor Hallucis Longus tendon rupture in RA-patients is associated with MTP 1 damage and pes planus

Directory of Open Access Journals (Sweden)

Buurke Jaap J

2007-11-01

Full Text Available Abstract Background To assess the prevalence of and relation between rupture or tenosynovitis of the Flexor Hallucis Longus (FHL tendon and range of motion, deformities and joint damage of the forefoot in RA patients with foot complaints. Methods Thirty RA patients with painful feet were analysed, their feet were examined clinically for the presence of pes planus and range of motion (ROM, radiographs were scored looking for the presence of forefoot damage, and ultrasound examination was performed, examining the presence of tenosyovitis or rupture of the FHL at the level of the medial malleolus. The correlation between the presence or absence of the FHL and ROM, forefoot damage and pes planus was calculated. Results In 11/60(18% of the feet, a rupture of the FHL was found. This was associated with a limited motion of the MTP1-joint, measured on the JAM (χ2 = 10.4, p = 0.034, a higher prevalence of pes planus (χ2 = 5.77, p = 0.016 and a higher prevalence of erosions proximal at the MTP-1 joint (χ2 = 12.3, p = 0.016, and joint space narrowing of the MTP1 joint (χ2 = 12.7, p = 0.013. Conclusion Rupture of the flexor hallucis longus tendon in RA-patients is associated with limited range of hallux motion, more erosions and joint space narrowing of the MTP-1-joint, as well as with pes planus.

Changes in skeletal muscle and tendon structure and function following genetic inactivation of myostatin in rats

Science.gov (United States)

Mendias, Christopher L; Lynch, Evan B; Gumucio, Jonathan P; Flood, Michael D; Rittman, Danielle S; Van Pelt, Douglas W; Roche, Stuart M; Davis, Carol S

2015-01-01

Myostatin is a negative regulator of skeletal muscle and tendon mass. Myostatin deficiency has been well studied in mice, but limited data are available on how myostatin regulates the structure and function of muscles and tendons of larger animals. We hypothesized that, in comparison to wild-type (MSTN+/+) rats, rats in which zinc finger nucleases were used to genetically inactivate myostatin (MSTNΔ/Δ) would exhibit an increase in muscle mass and total force production, a reduction in specific force, an accumulation of type II fibres and a decrease and stiffening of connective tissue. Overall, the muscle and tendon phenotype of myostatin-deficient rats was markedly different from that of myostatin-deficient mice, which have impaired contractility and pathological changes to fibres and their extracellular matrix. Extensor digitorum longus and soleus muscles of MSTNΔ/Δ rats demonstrated 20–33% increases in mass, 35–45% increases in fibre number, 20–57% increases in isometric force and no differences in specific force. The insulin-like growth factor-1 pathway was activated to a greater extent in MSTNΔ/Δ muscles, but no substantial differences in atrophy-related genes were observed. Tendons of MSTNΔ/Δ rats had a 20% reduction in peak strain, with no differences in mass, peak stress or stiffness. The general morphology and gene expression patterns were similar between tendons of both genotypes. This large rodent model of myostatin deficiency did not have the negative consequences to muscle fibres and extracellular matrix observed in mouse models, and suggests that the greatest impact of myostatin in the regulation of muscle mass may not be to induce atrophy directly, but rather to block hypertrophy signalling. PMID:25640143

Salvage Flexor Hallucis Longus Transfer for a Failed Achilles Repair: Endoscopic Technique.

Science.gov (United States)

Gonçalves, Sérgio; Caetano, Rubén; Corte-Real, Nuno

2015-10-01

Flexor hallucis longus (FHL) transfer is a well-established treatment option in failed Achilles tendon (AT) repair and has been routinely performed as an open procedure. We detail the surgical steps needed to perform an arthroscopic transfer of the FHL for a chronic AT rupture. The FHL tendon is harvested as it enters in its tunnel beneath the sustentaculum tali; a tunnel is then drilled in the calcaneus as near to the AT footprint as possible. By use of a suture-passing device, the free end of the FHL is advanced to the plantar aspect of the foot. After adequate tension is applied to the construct, the tendon is fixed in place with an interference screw in an inside-out fashion. This minimally invasive approach is a safe and valid alternative to classic open procedures with the obvious advantages of preserving the soft-tissue envelope and using a biologically intact tendon.

Electromiography comparison of distal and proximal lower limb muscle activity patterns during external perturbation in subjects with and without functional ankle instability.

Science.gov (United States)

Kazemi, Khadijeh; Arab, Amir Massoud; Abdollahi, Iraj; López-López, Daniel; Calvo-Lobo, César

2017-10-01

Ankle sprain is one of the most common injuries among athletes and the general population. Most ankle injuries commonly affect the lateral ligament complex. Changes in postural sway and hip abductor muscle strength may be generated after inversion ankle sprain. Therefore, the consequences of ankle injury may affect proximal structures of the lower limb. The aim is to describe and compare the activity patterns of distal and proximal lower limb muscles following external perturbation in individuals with and without functional ankle instability. The sample consisted of 16 women with functional ankle instability and 18 healthy women were recruited to participate in this research. The external perturbation via body jacket using surface electromyography, amplitude and onset of muscle activity of gluteus maximums, gluteus medius, tibialis anterior, and peroneus longus was recorded and analyzed during external perturbation. There were differences between the onset of muscles activity due to perturbation direction in the two groups (healthy and functional ankle instability). In the healthy group, there were statistically significant differences in amplitude of proximal muscle activity with distal muscle activity during front perturbation with eyes open and closed. In the functional ankle instability group; there were statistically significant differences in amplitude of proximal muscle activity with distal muscle activity during perturbation of the front and back with eyes open. There were statistically significant differences in the onset of muscle activity and amplitude of muscle activity, with-in and between groups (Pankle instability, activation patterns of the lower limb proximal muscles may be altered. Copyright © 2017 Elsevier B.V. All rights reserved.

Four cases of variations in the forearm extensor musculature in a study of hundred limbs and review of literature

Directory of Open Access Journals (Sweden)

Rao Mohandas

2006-01-01

Full Text Available All surgeons must bear in mind the existence of muscular variations when performing common tendon transfers. Presence of additional bellies and tendons of existing muscles or presence of additional muscles in unusual locations might misguide a surgeon, during surgery and also during diagnosis. In the present paper we are reporting four cases of variations encountered during the study of extensor muscles of the forearm in 100 limbs. In Case 1, additional bellies of extensor carpi radialis longus and extensor carpi radialis brevis and multiple tendons of insertion of abductor pollicis longus were observed in a single limb. In Case 2, an additional belly of the abductor pollicis longus was observed. In Case 3, a short muscle on the dorsum of the hand going to the index finger [extensor indicis brevis (EIB] was found in addition to the normal extensor indicis (EI. It was also observed that some of the most superficial fleshy fibers of EIB were getting inserted into the tendon of EI. In Case 4, a rare incidence of extensor digiti medii proprius was observed. Further, the related literature is reviewed and the clinical and surgical importance of these muscular variations in diagnosis and proper planning of treatment is discussed.

The ATP required for potentiation of skeletal muscle contraction is released via pannexin hemichannels.

Science.gov (United States)

Riquelme, Manuel A; Cea, Luis A; Vega, José L; Boric, Mauricio P; Monyer, Hannah; Bennett, Michael V L; Frank, Marina; Willecke, Klaus; Sáez, Juan C

2013-12-01

During repetitive stimulation of skeletal muscle, extracellular ATP levels raise, activating purinergic receptors, increasing Ca2+ influx, and enhancing contractile force, a response called potentiation. We found that ATP appears to be released through pannexin1 hemichannels (Panx1 HCs). Immunocytochemical analyses and function were consistent with pannexin1 localization to T-tubules intercalated with dihydropyridine and ryanodine receptors in slow (soleus) and fast (extensor digitorum longus, EDL) muscles. Isolated myofibers took up ethidium (Etd+) and released small molecules (as ATP) during electrical stimulation. Consistent with two glucose uptake pathways, induced uptake of 2-NBDG, a fluorescent glucose derivative, was decreased by inhibition of HCs or glucose transporter (GLUT4), and blocked by dual blockade. Adult skeletal muscles apparently do not express connexins, making it unlikely that connexin hemichannels contribute to the uptake and release of small molecules. ATP release, Etd+ uptake, and potentiation induced by repetitive electrical stimulation were blocked by HC blockers and did not occur in muscles of pannexin1 knockout mice. MRS2179, a P2Y1R blocker, prevented potentiation in EDL, but not soleus muscles, suggesting that in fast muscles ATP activates P2Y1 but not P2X receptors. Phosphorylation on Ser and Thr residues of pannexin1 was increased during potentiation, possibly mediating HC opening. Opening of Panx1 HCs during repetitive activation allows efflux of ATP, influx of glucose and possibly Ca2+ too, which are required for potentiation of contraction. This article is part of the Special Issue Section entitled 'Current Pharmacology of Gap Junction Channels and Hemichannels'. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of Fiber Type and Size on the Heterogeneity of Oxygen Distribution in Exercising Skeletal Muscle

Science.gov (United States)

Liu, Gang; Mac Gabhann, Feilim; Popel, Aleksander S.

2012-01-01

The process of oxygen delivery from capillary to muscle fiber is essential for a tissue with variable oxygen demand, such as skeletal muscle. Oxygen distribution in exercising skeletal muscle is regulated by convective oxygen transport in the blood vessels, oxygen diffusion and consumption in the tissue. Spatial heterogeneities in oxygen supply, such as microvascular architecture and hemodynamic variables, had been observed experimentally and their marked effects on oxygen exchange had been confirmed using mathematical models. In this study, we investigate the effects of heterogeneities in oxygen demand on tissue oxygenation distribution using a multiscale oxygen transport model. Muscles are composed of different ratios of the various fiber types. Each fiber type has characteristic values of several parameters, including fiber size, oxygen consumption, myoglobin concentration, and oxygen diffusivity. Using experimentally measured parameters for different fiber types and applying them to the rat extensor digitorum longus muscle, we evaluated the effects of heterogeneous fiber size and fiber type properties on the oxygen distribution profile. Our simulation results suggest a marked increase in spatial heterogeneity of oxygen due to fiber size distribution in a mixed muscle. Our simulations also suggest that the combined effects of fiber type properties, except size, do not contribute significantly to the tissue oxygen spatial heterogeneity. However, the incorporation of the difference in oxygen consumption rates of different fiber types alone causes higher oxygen heterogeneity compared to control cases with uniform fiber properties. In contrast, incorporating variation in other fiber type-specific properties, such as myoglobin concentration, causes little change in spatial tissue oxygenation profiles. PMID:23028531

Streptozotocin diabetes attenuates the effects of nondepolarizing neuromuscular relaxants on rat muscles.

Science.gov (United States)

Huang, Lina; Chen, Dan; Li, Shitong

2014-12-01

The hypothesis of this study was that diabetes-induced desensitization of rat soleus (SOL) and extensor digitorum longus (EDL) to non-depolarizing muscle relaxants (NDMRs) depends on the stage of diabetes and on the kind of NDMRs. We tested the different magnitude of resistance to vecuronium, cisatracurium, and rocuronium at different stages of streptozotocin (STZ)-induced diabetes by the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations from rats after 4 and 16 weeks of STZ treatment. The concentration-twitch tension curves were significantly shifted from those of the control group to the right in the diabetic groups. Concentration giving 50% of maximal inhibition (IC50) was larger in the diabetic groups for all the NDMRs. For rocuronium and cisatracurium in both SOL and EDL, IC50 was significantly larger in diabetic 16 weeks group than those in the diabetic 4 weeks group. For SOL/EDL, the IC50 ratios were significantly largest in the diabetic 16 weeks group, second largest in the diabetic 4 weeks group, and smallest for the control group. Diabetes-induced desensitization to NDMRs depended on the stage of diabetes and on the different kind of muscles observed while was independent on different kind of NDMRs. The resistance to NDMRs was stronger in the later stage of diabetes (16 versus 4 weeks after STZ treatment). Additionally, when monitoring in SOL, diabetes attenuated the actions of neuromuscular blockade more intensely than that in EDL. Nonetheless, the hyposensitivity to NDMRs in diabetes was not relevant for the kind of NDMRs.

The Comparing the Leg Muscles Electromyography during Single Leg Drop Landing in Pesplanus and Normal Men

Directory of Open Access Journals (Sweden)

mostafa bazvand

2016-03-01

Full Text Available Objective: pesplanus is one of the changes that brings about changes in muscle activation patterns. Being aware of muscles activity changes in various standing positions among pesplanus patients provides insights into preventing lower extremity injuries in this population. The aim of this study was to compare leg muscles electromyography during various standing positions in pesplanus and normal subjects. Methods: 60 healthy male university students, 30 subjects with pesplanus deformity (with average age 23/54±3/57 year, average height 175/34±7/62 cm, average weight 74/87±10/72 kg and 30 normal subjects (with average age 22/97±2/38 year, average height 176/6±5/59 cm, average weight 73/58±8/36 kg participated in this comparative study. Deformity of pesplanus was assessed with navicular drop test. Each subject performed single-leg landing dropping from 30cm height onto a force platform where muscles activity was recorded with EMG device. For data analysis, Matlab and Spss softwares were used and independent sample t-test was used to compare the dependent variables at a significance level of P &le 0/05. Results: Significant differences were observed between the two groups for the activities of the longus peroneus and anterior tibialis muscles ( p&le0/05 while no significant differences were observed in other muscles. Conclusion: The changes in the normal structure of the foot might affect muscle activities during standing, which can cause changes in the injury patterns. Therefore, it is proposed that focusing on corrective exercises and therapy plan can reduce these risks.

Acetylcholine and choline contents of rat skeletal muscle determined by a radioenzymatic microassay: effects of drugs

International Nuclear Information System (INIS)

Consolo, S.

1986-01-01

This paper describes a specific, radioenzymatic microassay for measuring picomole quantities of ACh in skeletal muscle. The levels of ACh as well ascholine in the extensor digitorum longus (EDL), soleus and gastrocnemiusmuscles of the rat are reported after focussed microwave irradiation to the hind limb to prevent post-mortem changes in ACh and choline contents. Particular attention was directed to the effect of some drugs potently affecting neuromuscular transmission at the end plate. Preparation of tissue samples, extraction and electrophoresis are described. A 26 ul portion of a second incubation mixture of tritium-acetylcoenzyme A and 14 ul of a partially purified choline acetyltransferase solution were added. A flow sheet giving an overview of he analytical steps involved in the method are shown

An in vivo model for studying the dynamics of intracellular free calcium changes in slow- and fast-twitch muscle fibres.

Science.gov (United States)

Bátkai, S; Rácz, I B; Ivanics, T; Tóth, A; Hamar, J; Slaaf, D W; Reneman, R S; Ligeti, L

1999-10-01

The understanding of the regulation of the free cytosolic [Ca2+] ([Ca2+]i) in skeletal muscle is hampered by the lack of techniques for quantifying free [Ca2+]i in muscle fibres in situ. We describe a model for studying the dynamics of free [Ca2+]i in the fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus (SOL) muscles of the rat in vivo using caffeine superfusion to induce changes in free [Ca2+]i. We assumed that differences in sensitivity between the two muscle types for this substance reflect differences in intracellular Ca2+ handling in the fibres of which these muscles consist. The Indo-1 ratiometric method, using intravital microscopy with incident light, was adapted to measure free [Ca2+]i in vivo. Fluorescence images were collected by means of a digital camera. Caffeine superfusion at 37 degrees C for 2 min, at concentrations of 1, 2, 5, 10 or 20 mmol/l, induced a concentration-dependent increase in free [Ca2+]i and revealed differences in caffeine sensitivity between the muscle types, with the SOL being more sensitive. In a separate set of experiments the contracture threshold, as assessed by topical application of caffeine, was determined in both muscle types. EDL had a higher threshold for developing contracture than SOL. These finding are in agreement with previous in vitro studies. We may conclude that the dynamics of free [Ca2+]i can be assessed reliably in intact mammalian muscle in vivo.

Skeletal myofiber VEGF regulates contraction-induced perfusion and exercise capacity but not muscle capillarity in adult mice.

Science.gov (United States)

Knapp, Amy E; Goldberg, Daniel; Delavar, Hamid; Trisko, Breanna M; Tang, Kechun; Hogan, Michael C; Wagner, Peter D; Breen, Ellen C

2016-07-01

A single bout of exhaustive exercise signals expression of vascular endothelial growth factor (VEGF) in the exercising muscle. Previous studies have reported that mice with life-long deletion of skeletal myofiber VEGF have fewer capillaries and a severe reduction in endurance exercise. However, in adult mice, VEGF gene deletion conditionally targeted to skeletal myofibers limits exercise capacity without evidence of capillary regression. To explain this, we hypothesized that adult skeletal myofiber VEGF acutely regulates skeletal muscle perfusion during muscle contraction. A tamoxifen-inducible skeletal myofiber-specific VEGF gene deletion mouse (skmVEGF-/-) was used to reduce skeletal muscle VEGF protein by 90% in adult mice. Three weeks after inducing deletion of the skeletal myofiber VEGF gene, skmVEGF-/- mice exhibited diminished maximum running speed (-10%, P Contraction-induced perfusion measured by optical imaging during a period of electrically stimulated muscle contraction was 85% lower in skmVEGF-/- than control mice. No evidence of capillary rarefication was detected in the soleus, gastrocnemius, and extensor digitorum longus (EDL) up to 8 wk after tamoxifen-induced VEGF ablation, and contractility and fatigue resistance of the soleus measured ex vivo were also unchanged. The force-frequency of the EDL showed a small right shift, but fatigue resistance did not differ between EDL from control and skmVEGF-/- mice. These data suggest myofiber VEGF is required for regulating perfusion during periods of contraction and may in this manner affect endurance capacity. Copyright © 2016 the American Physiological Society.

Intracellular uptake and degradation of extracellular tracers in mouse skeletal muscle in vitro: the effect of denervation

International Nuclear Information System (INIS)

Libelius, R.; Lundquist, I.; Templeton, W.; Thesleff, S.

1978-01-01

Innervated and chronically denervated mouse skeletal muscles have been incubated under various conditions in a Ringer solution containing one of the three macromolecules [ 3 H] α-neurotoxin, [ 3 H]inulin and horseradish peroxidase. Following extensive wash-out for 4 h of the extracellular compartment, the amount of each macromolecule retained intracellularly was obtained. Intracellular uptake of a [ 3 H]monoacetylated α-neurotoxin in vitro at 37 C was found to be increased in denervated mouse extensor digitorum longus muscles compared to innervated control muscles. Similarly, the uptake in vitro at 37 C of [ 3 H] inulin and horseradish peroxidase was also increased in denervated muscles. At 4 C the uptake of [ 3 H]inulin and horseradish peroxidase was markedly reduced. Protamine was found to stimulate the uptake of [ 3 H]inulin at 37 C, but not at 4 C. Reduction in specific activity by addition of 50-fold excess of unlabelled inulin failed to affect the uptake of [ 3 H]inulin suggesting that this uptake process obeyed bulk kinetics. Furthermore, the endocytized [ 3 H]inulin was found to be strongly retained in the muscles since prolonged washing or addition of unlabelled inulin to the washing solution did not reduce the uptake. Characterization of [ 3 H]inulin taken up by the muscles was performed by gel chromatography on Sephadex G-25. Using a purified [ 3 H]inulin solution it was observed that about 45% of the total radioactivity remaining in the muscles was eluted as [ 3 H]inulin. Additional radioactivity consisted of lower molecular weight compounds. These degradation products of [ 3 H]inulin were only present in the muscle homogenate and were not detected in the incubation solution. The results suggest that intracellular uptake of different macromolecules by endocytosis in skeletal muscles increases following denervation, and that following uptake, degradation of the endocytized material may occur. (author)

Neopterin/7,8-dihydroneopterin is elevated in Duchenne muscular dystrophy patients and protects mdx skeletal muscle function.

Science.gov (United States)

Lindsay, Angus; Schmiechen, Alexandra; Chamberlain, Christopher M; Ervasti, James M; Lowe, Dawn A

2018-05-23

Macrophage infiltration is a hallmark of dystrophin-deficient muscle. We tested the hypothesis that Duchenne muscular dystrophy (DMD) patients would have elevated levels of the macrophage synthesized pterins, neopterin and 7,8-dihydroneopterin compared to unaffected age-matched controls. Urinary neopterin/creatinine and 7,8-dihydroneopterin/creatinine were elevated in DMD patients and 7,8-dihydroneopterin/creatinine was associated with patient age and ambulation. 7,8-dihydroneopterin correction with specific gravity was also elevated in DMD patients. Because 7,8-dihydroneopterin is an antioxidant, we then identified a potential role for 7,8-dihydroneopterin in disease pathology. We assessed whether 7,8-dihydroneopterin could 1) protect against isometric force loss in wildtype skeletal muscle exposed to various pro-oxidants, and 2) protect wildtype and mdx muscle from eccentric contraction-induced force drop which has an oxidative component. Force drop was elicited in isolated Extensor Digitorum Longus (EDL) muscles by 10 eccentric contractions and recovery of force following the contractions was measured in the presence of exogenous 7,8-dihydroneopterin. 7,8-dihydroneopterin attenuated isometric force loss by wildtype EDL muscles when challenged by H 2 O 2 and HOCl, but exacerbated force loss when challenged by SIN-1 (NO · , O 2 · , ONOO - ). 7,8-dihydroneopterin attenuated eccentric contraction-induced force drop in mdx muscle. Isometric force by EDL muscles of mdx mice also recovered to a greater degree following eccentric contractions in the presence of 7,8-dihydroneopterin. The results corroborate macrophage activation in DMD patients, provide a potential protective role for 7,8-dihydroneopterin in the susceptibility of dystrophic muscle to eccentric contractions and indicate oxidative stress contributes to eccentric contraction-induced force drop in mdx skeletal muscle. This article is protected by copyright. All rights reserved. This article is protected by

Stress fracture in posterior aspect of the tibia

International Nuclear Information System (INIS)

Moon, Tae Yong; Jung, Hyun Woo; Park, Chung Hun; Chun, Kyung Ah; Koo, Bong Sig; Lee, Sang Yong

1999-01-01

To determine correlation between stress fracture of the posterior tibia and flexor digitorum longus muscle injury caused by athletic or sporting activity during adolescence. Eleven cases diagnosed as stress fracture after X-ray and MR imaging of the lower leg were reviewed. With regard to each fracture, the following features were noted : age, sex, and athletic or sporting activity of the patient, and site. Using MR imaging techniques, axial and sagittal T1 and T2 weighted imaged were obtained in all cases and T1-Gd DTPA images in seven. The activities undertaken were running (n=3), football (n=2), ballet (n=2), taekwando (n=1), badminton (n=1), field hockey (n=1), and basketball (n=1). MR images revealed localized cortical thickness (n=11), linear intramedullary callus showing a low signal on T1 and T2 weighted images (n=9), marrow hyperemia (n=7), and flexor digitorum longus muscle injury showing a high signal on T1-Gd DTPA and T2 weighted image (n=7). Stress fracture of the posterior tibia might be induced by flexor digitorum longus muscle activity induced by athletic or sporting activities during adolescence

Stress fracture in posterior aspect of the tibia

Energy Technology Data Exchange (ETDEWEB)

Moon, Tae Yong; Jung, Hyun Woo; Park, Chung Hun [Pusan National Univ. College of Medicine, Pusan (Korea, Republic of); Chun, Kyung Ah [Catholic Univ Hospital, Pusan (Korea, Republic of); Koo, Bong Sig [Donga Univ. Hospital, Pusan (Korea, Republic of); Lee, Sang Yong [Chunbuk Natinoal Univ. Hospital, Chunju (Korea, Republic of)

1999-01-01

To determine correlation between stress fracture of the posterior tibia and flexor digitorum longus muscle injury caused by athletic or sporting activity during adolescence. Eleven cases diagnosed as stress fracture after X-ray and MR imaging of the lower leg were reviewed. With regard to each fracture, the following features were noted : age, sex, and athletic or sporting activity of the patient, and site. Using MR imaging techniques, axial and sagittal T1 and T2 weighted imaged were obtained in all cases and T1-Gd DTPA images in seven. The activities undertaken were running (n=3), football (n=2), ballet (n=2), taekwando (n=1), badminton (n=1), field hockey (n=1), and basketball (n=1). MR images revealed localized cortical thickness (n=11), linear intramedullary callus showing a low signal on T1 and T2 weighted images (n=9), marrow hyperemia (n=7), and flexor digitorum longus muscle injury showing a high signal on T1-Gd DTPA and T2 weighted image (n=7). Stress fracture of the posterior tibia might be induced by flexor digitorum longus muscle activity induced by athletic or sporting activities during adolescence.

Effects of microgravity on muscle and cerebral cortex: a suggested interaction

Science.gov (United States)

D'Amelio, F.; Fox, R. A.; Wu, L. C.; Daunton, N. G.; Corcoran, M. L.

The ``slow'' antigravity muscle adductor longus was studied in rats after 14 days of spaceflight (SF). The techniques employed included standard methods for light microscopy, neural cell adhesion molecule (N-CAM) immunocytochemistry and electron microscopy. Light and electron microscopy revealed myofiber atrophy, segmental necrosis and regenerative myofibers. Regenerative myofibers were N-CAM immunoreactive (N-CAM-IR). The neuromuscular junctions showed axon terminals with a decrease or absence of synaptic vesicles, degenerative changes, vacant axonal spaces and changes suggestive of axonal sprouting. No alterations of muscle spindles was seen either by light or electron microscopy. These observations suggest that muscle regeneration and denervation and synaptic remodeling at the level of the neuromuscular junction may take place during spaceflight. In a separate study, GABA immunoreactivity (GABA-IR) was evaluated at the level of the hindlimb representation of the rat somatosensory cortex after 14 days of hindlimb unloading by tail suspension (``simulated'' microgravity). A reduction in number of GABA-immunoreactive cells with respect to the control animals was observed in layer Va and Vb. GABA-IR terminals were also reduced in the same layers, particularly those terminals surrounding the soma and apical dendrites of pyramidal cells in layer Vb. On the basis of previous morphological and behavioral studies of the neuromuscular system after spaceflight and hindlimb suspension it is suggested that after limb unloading there are alterations of afferent signaling and feedback information from intramuscular receptors to the cerebral cortex due to modifications in the reflex organization of hindlimb muscle groups. We propose that the changes observed in GABA immunoreactivity of cells and terminals is an expression of changes in their modulatory activity to compensate for the alterations in the afferent information.

Dietary fat influences the expression of contractile and metabolic genes in rat skeletal muscle.

Directory of Open Access Journals (Sweden)

Wataru Mizunoya

Full Text Available Dietary fat plays a major role in obesity, lipid metabolism, and cardiovascular diseases. To determine whether the intake of different types of dietary fats affect the muscle fiber types that govern the metabolic and contractile properties of the skeletal muscle, we fed male Wistar rats with a 15% fat diet derived from different fat sources. Diets composed of soybean oil (n-6 polyunsaturated fatty acids (PUFA-rich, fish oil (n-3 PUFA-rich, or lard (low in PUFAs were administered to the rats for 4 weeks. Myosin heavy chain (MyHC isoforms were used as biomarkers to delineate the skeletal muscle fiber types. Compared with soybean oil intake, fish oil intake showed significantly lower levels of the fast-type MyHC2B and higher levels of the intermediate-type MyHC2X composition in the extensor digitorum longus (EDL muscle, which is a fast-type dominant muscle. Concomitantly, MyHC2X mRNA levels in fish oil-fed rats were significantly higher than those observed in the soybean oil-fed rats. The MyHC isoform composition in the lard-fed rats was an intermediate between that of the fish oil and soybean oil-fed rats. Mitochondrial uncoupling protein 3, pyruvate dehydrogenase kinase 4, and porin mRNA showed significantly upregulated levels in the EDL of fish oil-fed rats compared to those observed in soybean oil-fed and lard-fed rats, implying an activation of oxidative metabolism. In contrast, no changes in the composition of MyHC isoforms was observed in the soleus muscle, which is a slow-type dominant muscle. Fatty acid composition in the serum and the muscle was significantly influenced by the type of dietary fat consumed. In conclusion, dietary fat affects the expression of genes related to the contractile and metabolic properties in the fast-type dominant skeletal muscle, where the activation of oxidative metabolism is more pronounced after fish oil intake than that after soybean oil intake.

Adaptation in properties of skeletal muscle to coronary artery occlusion/reperfusion in rats

International Nuclear Information System (INIS)

Ogoh, Shigehiko; Taguchi, Sadayoshi

2002-01-01

The present study was designed to determine if changes in function and metabolism of heart muscle induce alterations in characteristics of skeletal muscle. We investigated the histochemical and biochemical properties of soleus (SOL) and extensor digitorum longus (EDL) muscles in Wistar rats at the chronic phase after coronary artery occlusion/reperfusion. The size of myocardial infarct region was evaluated using a high resolution pinhole single photo emission computed tomography (SPECT) system. 4wk after left coronary artery occlusion/reperfusion, the SOL and EDL of hindlimb were dissected out and immersed in isopentane cooled with liquid nitrogen for subsequent histochemical and biochemical analysis. From SPECT imaging, the blood circulation was recovered, but the recovery of fatty acid metabolism was not observed in infarct region of heart. Citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD) activities in infarct region of heart were lower in the myocardial infarction (MI, n=6) group compared with that of age-matched sham-operated (Sham, n=6) group. In addition, heart muscle hypertrophy caused by the dysfunction in MI group was observed. In skeletal muscle, the atrophy and transition of fiber type distribution in MI group, reported in previous studies of heart failure, were not observed. However, the succinate dehydrogenase (SDH) activity in the slow twitch oxidative (SO) from SOL of MI group decreased by 9.8% and in the fast twitch oxidative glycolytic fibers (FOG), 8.0% as compared with sham group. Capillary density of the SO fibers from SOL of MI group also reduced by 18.5% and in the FOG fibers, 18.2% as compared with Sham group. Decreased capillary density in this study related significantly to decreased SDH activity of single muscle fibers in chronic phase of perfusion after surgical infarction. Our results make it clear that there is a difference in the reaction of skeletal muscle to coronary artery occlusion/reperfusion compared with chronic

Adaptation in properties of skeletal muscle to coronary artery occlusion/reperfusion in rats

Energy Technology Data Exchange (ETDEWEB)

Ogoh, Shigehiko [Univ. of North Texas, Fort Worth, TX (United States). Health Science Center; Hirai, Taku [Kyoto Univ. (Japan). Graduate School of Medicine; Nohara, Ryuuji [Kitano Hospital, Osaka (Japan); Taguchi, Sadayoshi [Kyoto Univ. (Japan). Graduate School of Human and Environmental Studies

2002-10-01

The present study was designed to determine if changes in function and metabolism of heart muscle induce alterations in characteristics of skeletal muscle. We investigated the histochemical and biochemical properties of soleus (SOL) and extensor digitorum longus (EDL) muscles in Wistar rats at the chronic phase after coronary artery occlusion/reperfusion. The size of myocardial infarct region was evaluated using a high resolution pinhole single photo emission computed tomography (SPECT) system. 4wk after left coronary artery occlusion/reperfusion, the SOL and EDL of hindlimb were dissected out and immersed in isopentane cooled with liquid nitrogen for subsequent histochemical and biochemical analysis. From SPECT imaging, the blood circulation was recovered, but the recovery of fatty acid metabolism was not observed in infarct region of heart. Citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD) activities in infarct region of heart were lower in the myocardial infarction (MI, n=6) group compared with that of age-matched sham-operated (Sham, n=6) group. In addition, heart muscle hypertrophy caused by the dysfunction in MI group was observed. In skeletal muscle, the atrophy and transition of fiber type distribution in MI group, reported in previous studies of heart failure, were not observed. However, the succinate dehydrogenase (SDH) activity in the slow twitch oxidative (SO) from SOL of MI group decreased by 9.8% and in the fast twitch oxidative glycolytic fibers (FOG), 8.0% as compared with sham group. Capillary density of the SO fibers from SOL of MI group also reduced by 18.5% and in the FOG fibers, 18.2% as compared with Sham group. Decreased capillary density in this study related significantly to decreased SDH activity of single muscle fibers in chronic phase of perfusion after surgical infarction. Our results make it clear that there is a difference in the reaction of skeletal muscle to coronary artery occlusion/reperfusion compared with chronic

Effects of the activin A-myostatin-follistatin system on aging bone and muscle progenitor cells

Science.gov (United States)

Bowser, Matthew; Herberg, Samuel; Arounleut, Phonepasong; Shi, Xingming; Fulzele, Sadanand; Hill, William D.; Isales, Carlos M.; Hamrick, Mark W.

2013-01-01

The activin A-myostatin-follistatin system is thought to play an important role in the regulation of muscle and bone mass throughout growth, development, and aging; however, the effects of these ligands on progenitor cell proliferation and differentiation in muscle and bone are not well understood. In addition, age-associated changes in the relative expression of these factors in musculoskeletal tissues have not been described. We therefore examined changes in protein levels of activin A, follistatin, and myostatin (GDF-8) in both muscle and bone with age in C57BL6 mice using ELISA. We then investigated the effects of activin A, myostatin and follistatin on the proliferation and differentiation of primary myoblasts and mouse bone marrow stromal cells (BMSCs) in vitro. Myostatin levels and the myostatin:follistatin ratio increased with age in the primarily slow-twitch mouse soleus muscle, whereas the pattern was reversed with age in the fast-twitch extensor digitorum longus muscle. Myostatin levels and the myostatin: follistatin ratio increased significantly (+75%) in mouse bone marrow with age, as did activin A levels (+17%). Follistatin increased the proliferation of primary myoblasts from both young and aged mice, whereas myostatin increased proliferation of younger myoblasts but decreased proliferation of older myoblasts. Myostatin reduced proliferation of both young and aged BMSCs in a dose-dependent fashion, and activin A increased mineralization in both young and aged BMSCs. Together these data suggest that aging in mice is accompanied by changes in the expression of activin A and myostatin, as well as changes in the response of bone and muscle progenitor cells to these factors. Myostatin appears to play a particularly important role in the impaired proliferative capacity of muscle and bone progenitor cells from aged mice. PMID:23178301

The Effects of Active Straight Leg Raising on Tonicity and Activity of Pelvic Stabilizer Muscles

Directory of Open Access Journals (Sweden)

Azadeh Shadmehr

2011-01-01

Full Text Available Objective: Active straight leg raising (SLR test is advocated as a valid diagnostic method in diagnosis of sacroiliac joint (SIJ dysfunction that can assess the quality of load transfer between trunk and lower limb. The aim of this study is Comparison of changes in tonicity and activity of pelvic stabilizer muscles during active SLR, between healthy individuals and patients with sacroiliac joint pain. Materials & Methods: A case – control study was designed in 26 women (19-50 years old. With use of simple sampling, surface electromyography from rectus abdominis, external oblique, internal oblique, adductor longus, erector spine, gluteus maximus and biceps femoris was recorded in 26 subjects (15 healthy females and 11 females with sacroiliac pain in resting position and during active SLR test. Resting muscle tonicity and rms during ramp time and hold time in active SLR test were assessed by non parametric-two independent sample test. Results: Biceps femoris activity in resting position was significantly larger in patients group (P<0.05. During the active SLR, the women with sacroiliac joint pain used much less activity in some pelvic stabilizer muscles compared to the healthy subjects (P<0.05. Conclusion: The increased resting tonicity of biceps femoris and decreased activity of pelvic stabilizer muscles in subjects with sacroiliac joint pain, suggests an alteration in the strategy for lumbopelvic stabilization that may disrupt load transference through the pelvis.

Developmental changes in the activation properties and ultrastructure of fast- and slow-twitch muscles from fetal sheep.

Science.gov (United States)

West, J M; Barclay, C J; Luff, A R; Walker, D W

1999-04-01

At early stages of muscle development, skeletal muscles contract and relax slowly, regardless of whether they are destined to become fast- or slow-twitch. In this study, we have characterised the activation profiles of developing fast- and slow-twitch muscles from a precocial species, the sheep, to determine if the activation profiles of the muscles are characteristically slow when both the fast- and slow-twitch muscles have slow isometric contraction profiles. Single skinned muscle fibres from the fast-twitch flexor digitorum longus (FDL) and slow-twitch soleus muscles from fetal (gestational ages 70, 90, 120 and 140 days; term 147 days) and neonatal (8 weeks old) sheep were used to determine the isometric force-pCa (pCa = -log10[Ca2+]) and force-pSr relations during development. Fast-twitch mammalian muscles generally have a greatly different sensitivity to Ca2+ and Sr2+ whereas slow-twitch muscles have a similar sensitivity to these divalent cations. At all ages studied, the force-pCa and force-pSr relations of the FDL muscle were widely separated. The mean separation of the mid-point of the curves (pCa50-pSr50) was approximately 1.1. This is typical of adult fast-twitch muscle. The force-pCa and force-pSr curves for soleus muscle were also widely separated at 70 and 90 days gestation (pCa50-pSr50 approximately 0.75); between 90 days and 140 days this separation decreased significantly to approximately 0.2. This leads to a paradoxical situation whereby at early stages of muscle development the fast muscles have contraction dynamics of slow muscles but the slow muscles have activation profiles more characteristic of fast muscles. The time course for development of the FDL and soleus is different, based on sarcomere structure with the soleus muscle developing clearly defined sarcomere structure earlier in gestation than the FDL. At 70 days gestation the FDL muscle had no clearly defined sarcomeres. Force (N cm-2) increased almost linearly between 70 and 140 days

Finite element modeling of aponeurotomy: altered intramuscular myofascial force transmission yields complex sarcomere length distributions determining acute effects

NARCIS (Netherlands)

Yucesoy, C.A.; Koopman, Hubertus F.J.M.; Grootenboer, H.J.; Huijing, P.A.J.B.M.

2007-01-01

Finite element modeling of aponeurotomized rat extensor digitorium longus muscle was performed to investigate the acute effects of proximal aponeurotomy. The specific goal was to assess the changes in lengths of sarcomeres within aponeurotomized muscle and to explain how the intervention leads to

Cervical stability training with and without core stability training for patients with cervical disc herniation: A randomized, single-blind study.

Science.gov (United States)

Buyukturan, B; Guclu-Gunduz, A; Buyukturan, O; Dadali, Y; Bilgin, S; Kurt, E E

2017-11-01

This study aims at evaluating and comparing the effects of cervical stability training to combined cervical and core stability training in patients with neck pain and cervical disc herniation. Fifty patients with neck pain and cervical disc herniation were included in the study, randomly divided into two groups as cervical stability and cervical-core stability. Training was applied three times a week in three phases, and lasted for a total duration of 8 weeks. Pain, activation and static endurance of deep cervical flexor muscles, static endurance of neck muscles, cross-sectional diameter of M. Longus Colli, static endurance of trunk muscles, disability and kinesiophobia were assessed. Pain, activation and static endurance of deep cervical flexors, static endurance of neck muscles, cross-sectional diameter of M. Longus Colli, static endurance of trunk muscles, disability and kinesiophobia improved in both groups following the training sessions (p training methods revealed that the cervical stability group produced a greater increase in the right transverse diameter of M. Longus Colli (p training provided benefit to patients with cervical disc herniation. The addition of core stability training did not provide any additional significant benefit. Further research is required to investigate the efficacy of combining other techniques with cervical stability training in patients with cervical disc herniation. Both cervical stability training and its combination with core stability training were significantly and similarly effective on neck pain and neck muscle endurance in patients with cervical disc herniation. © 2017 European Pain Federation - EFIC®.

Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles.

Science.gov (United States)

Barclay, C J

2012-12-01

The aims of this study were to quantify the Ca(2+) release underlying twitch contractions of mammalian fast- and slow-twitch muscle and to comprehensively describe the transient inactivation of Ca(2+) release following a stimulus. Experiments were performed using bundles of fibres from mouse extensor digitorum longus (EDL) and soleus muscles. Ca(2+) release was quantified from the amount of ATP used to remove Ca(2+) from the myoplasm following stimulation. ATP turnover by crossbridges was blocked pharmacologically (N-benzyl-p-toluenesulphonamide for EDL, blebbistatin for soleus) and muscle heat production was used as an index of Ca(2+) pump ATP turnover. At 20°C, Ca(2+) release in response to a single stimulus was 34 and 84 μmol (kg muscle)(-1) for soleus and EDL, respectively, and increased with temperature (30°C: soleus, 61 μmol kg(-1); EDL, 168 μmol kg(-1)). Delivery of another stimulus within 100 ms of the first produced a smaller Ca(2+) release. The maximum magnitude of the decrease in Ca(2+) release was greater in EDL than soleus. Ca(2+) release recovered with an exponential time course which was faster in EDL (mean time constant at 20°C, 32.1 ms) than soleus (65.6 ms) and faster at 30°C than at 20°C. The amounts of Ca(2+) released and crossbridge cycles performed are consistent with a scheme in which Ca(2+) binding to troponin-C allowed an average of ∼1.7 crossbridge cycles in the two muscles.

Rac1 and AMPK Account for the Majority of Muscle Glucose Uptake Stimulated by Ex Vivo Contraction but Not In Vivo Exercise.

Science.gov (United States)

Sylow, Lykke; Møller, Lisbeth L V; Kleinert, Maximilian; D'Hulst, Gommaar; De Groote, Estelle; Schjerling, Peter; Steinberg, Gregory R; Jensen, Thomas E; Richter, Erik A

2017-06-01

Exercise bypasses insulin resistance to increase glucose uptake in skeletal muscle and therefore represents an important alternative to stimulate glucose uptake in insulin-resistant muscle. Both Rac1 and AMPK have been shown to partly regulate contraction-stimulated muscle glucose uptake, but whether those two signaling pathways jointly account for the entire signal to glucose transport is unknown. We therefore studied the ability of contraction and exercise to stimulate glucose transport in isolated muscles with AMPK loss of function combined with either pharmacological inhibition or genetic deletion of Rac1.Muscle-specific knockout (mKO) of Rac1, a kinase-dead α2 AMPK (α2KD), and double knockout (KO) of β1 and β2 AMPK subunits (β1β2 KO) each partially decreased contraction-stimulated glucose transport in mouse soleus and extensor digitorum longus (EDL) muscle. Interestingly, when pharmacological Rac1 inhibition was combined with either AMPK β1β2 KO or α2KD, contraction-stimulated glucose transport was almost completely inhibited. Importantly, α2KD+Rac1 mKO double-transgenic mice also displayed severely impaired contraction-stimulated glucose transport, whereas exercise-stimulated glucose uptake in vivo was only partially reduced by Rac1 mKO with no additive effect of α2KD. It is concluded that Rac1 and AMPK together account for almost the entire ex vivo contraction response in muscle glucose transport, whereas only Rac1, but not α2 AMPK, regulates muscle glucose uptake during submaximal exercise in vivo. © 2017 by the American Diabetes Association.

Volume regulation in mammalian skeletal muscle: the role of sodium-potassium-chloride cotransporters during exposure to hypertonic solutions.

Science.gov (United States)

Lindinger, Michael I; Leung, Matthew; Trajcevski, Karin E; Hawke, Thomas J

2011-06-01

Controversy exists as to whether mammalian skeletal muscle is capable of volume regulation in response to changes in extracellular osmolarity despite evidence that muscle fibres have the required ion transport mechanisms to transport solute and water in situ. We addressed this issue by studying the ability of skeletal muscle to regulate volume during periods of induced hyperosmotic stress using single, mouse extensor digitorum longus (EDL) muscle fibres and intact muscle (soleus and EDL). Fibres and intact muscles were loaded with the fluorophore, calcein, and the change in muscle fluorescence and width (single fibres only) used as a metric of volume change. We hypothesized that skeletal muscle exposed to increased extracellular osmolarity would elicit initial cellular shrinkage followed by a regulatory volume increase (RVI) with the RVI dependent on the sodium–potassium–chloride cotransporter (NKCC). We found that single fibres exposed to a 35% increase in extracellular osmolarity demonstrated a rapid, initial 27–32% decrease in cell volume followed by a RVI which took 10-20 min and returned cell volume to 90–110% of pre-stimulus values. Within intact muscle, exposure to increased extracellular osmolarity of varying degrees also induced a rapid, initial shrinkage followed by a gradual RVI, with a greater rate of initial cell shrinkage and a longer time for RVI to occur with increasing extracellular tonicities. Furthermore, RVI was significantly faster in slow-twitch soleus than fast-twitch EDL. Pre-treatment of muscle with bumetanide (NKCC inhibitor) or ouabain (Na+,K+-ATPase inhibitor), increased the initial volume loss and impaired the RVI response to increased extracellular osmolarity indicating that the NKCC is a primary contributor to volume regulation in skeletal muscle. It is concluded that mouse skeletal muscle initially loses volume then exhibits a RVI when exposed to increases in extracellular osmolarity. The rate of RVI is dependent on the

Magnetic Resonance Assessment of Hypertrophic and Pseudo-Hypertrophic Changes in Lower Leg Muscles of Boys with Duchenne Muscular Dystrophy and Their Relationship to Functional Measurements.

Science.gov (United States)

Vohra, Ravneet S; Lott, Donovan; Mathur, Sunita; Senesac, Claudia; Deol, Jasjit; Germain, Sean; Bendixen, Roxanna; Forbes, Sean C; Sweeney, H Lee; Walter, Glenn A; Vandenborne, Krista

2015-01-01

The primary objectives of this study were to evaluate contractile and non-contractile content of lower leg muscles of boys with Duchenne muscular dystrophy (DMD) and determine the relationships between non-contractile content and functional abilities. Lower leg muscles of thirty-two boys with DMD and sixteen age matched unaffected controls were imaged. Non-contractile content, contractile cross sectional area and non-contractile cross sectional area of lower leg muscles (tibialis anterior, extensor digitorum longus, peroneal, medial gastrocnemius and soleus) were assessed by magnetic resonance imaging (MRI). Muscle strength, timed functional tests and the Brooke lower extremity score were also assessed. Non-contractile content of lower leg muscles (peroneal, medial gastrocnemius, and soleus) was significantly greater than control group (pmuscles correlated with Brooke score (rs = 0.64-0.84) and 30 feet walk (rs = 0.66-0.80). Dorsiflexor (DF) and plantarflexor (PF) specific torque was significantly different between the groups. Overall, non-contractile content of the lower leg muscles was greater in DMD than controls. Furthermore, there was an age dependent increase in contractile content in the medial gastrocnemius of boys with DMD. The findings of this study suggest that T1 weighted MR images can be used to monitor disease progression and provide a quantitative estimate of contractile and non-contractile content of tissue in children with DMD.

Caffeine and contraction synergistically stimulate 5′-AMP-activated protein kinase and insulin-independent glucose transport in rat skeletal muscle

Science.gov (United States)

Tsuda, Satoshi; Egawa, Tatsuro; Kitani, Kazuto; Oshima, Rieko; Ma, Xiao; Hayashi, Tatsuya

2015-01-01

5′-Adenosine monophosphate-activated protein kinase (AMPK) has been identified as a key mediator of contraction-stimulated insulin-independent glucose transport in skeletal muscle. Caffeine acutely stimulates AMPK in resting skeletal muscle, but it is unknown whether caffeine affects AMPK in contracting muscle. Isolated rat epitrochlearis muscle was preincubated and then incubated in the absence or presence of 3 mmol/L caffeine for 30 or 120 min. Electrical stimulation (ES) was used to evoke tetanic contractions during the last 10 min of the incubation period. The combination of caffeine plus contraction had additive effects on AMPKα Thr172 phosphorylation, α-isoform-specific AMPK activity, and 3-O-methylglucose (3MG) transport. In contrast, caffeine inhibited basal and contraction-stimulated Akt Ser473 phosphorylation. Caffeine significantly delayed muscle fatigue during contraction, and the combination of caffeine and contraction additively decreased ATP and phosphocreatine contents. Caffeine did not affect resting tension. Next, rats were given an intraperitoneal injection of caffeine (60 mg/kg body weight) or saline, and the extensor digitorum longus muscle was dissected 15 min later. ES of the sciatic nerve was performed to evoke tetanic contractions for 5 min before dissection. Similar to the findings from isolated muscles incubated in vitro, the combination of caffeine plus contraction in vivo had additive effects on AMPK phosphorylation, AMPK activity, and 3MG transport. Caffeine also inhibited basal and contraction-stimulated Akt phosphorylation in vivo. These findings suggest that caffeine and contraction synergistically stimulate AMPK activity and insulin-independent glucose transport, at least in part by decreasing muscle fatigue and thereby promoting energy consumption during contraction. PMID:26471759

Effects of thyroid hormones on calcium contents and 45Ca exchange in rat skeletal muscle

International Nuclear Information System (INIS)

Everts, M.E.; Clausen, T.

1986-01-01

In 4-wk-old rats, pretreatment with L-triiodothyronine (T3) increased calcium content by 100% and the 30-min 45 Ca uptake by 64% in the soleus, whereas the extensor digitorum longus (EDL) muscle showed no significant change. The stimulation of 45 Ca uptake was resistant to dantrolene and methoxyverapamil (D600) and could not be attributed to altered permeability of the plasma membrane to calcium, but appears to reflect increased net accumulation of calcium in intracellular pools. The stimulating effect of high K0 (20 mM) on 45 Ca uptake was more pronounced in soleus than in EDL and could be suppressed by dantrolene and D600. The results indicate that the effects of T3 on calcium content and 45 Ca exchange are primarily exerted on muscles containing a large proportion of slow-twitch, oxidative fibers. In soleus muscle from hyperthyroid rats the stimulating effects of high K0 on 45 Ca uptake and lactate production were, respectively, 3.4 and 4.5 times larger than in those obtained from controls. These observations further support the earlier proposed idea [C. van Hardeveld and T. Clausen. Am. J. Physiol. 247 (Endocrinol. Metab. 10): E421-E430, 1984] that the metabolic effects of thyroid hormone depend on the availability of cellular as well as extracellular calcium

Effects of thyroid hormones on calcium contents and 45Ca exchange in rat skeletal muscle

Energy Technology Data Exchange (ETDEWEB)

Everts, M.E.; Clausen, T.

1986-09-01

In 4-wk-old rats, pretreatment with L-triiodothyronine (T3) increased calcium content by 100% and the 30-min /sup 45/Ca uptake by 64% in the soleus, whereas the extensor digitorum longus (EDL) muscle showed no significant change. The stimulation of /sup 45/Ca uptake was resistant to dantrolene and methoxyverapamil (D600) and could not be attributed to altered permeability of the plasma membrane to calcium, but appears to reflect increased net accumulation of calcium in intracellular pools. The stimulating effect of high K0 (20 mM) on /sup 45/Ca uptake was more pronounced in soleus than in EDL and could be suppressed by dantrolene and D600. The results indicate that the effects of T3 on calcium content and /sup 45/Ca exchange are primarily exerted on muscles containing a large proportion of slow-twitch, oxidative fibers. In soleus muscle from hyperthyroid rats the stimulating effects of high K0 on /sup 45/Ca uptake and lactate production were, respectively, 3.4 and 4.5 times larger than in those obtained from controls. These observations further support the earlier proposed idea (C. van Hardeveld and T. Clausen. Am. J. Physiol. 247 (Endocrinol. Metab. 10): E421-E430, 1984) that the metabolic effects of thyroid hormone depend on the availability of cellular as well as extracellular calcium.

Magnetic Resonance Assessment of Hypertrophic and Pseudo-Hypertrophic Changes in Lower Leg Muscles of Boys with Duchenne Muscular Dystrophy and Their Relationship to Functional Measurements.

Directory of Open Access Journals (Sweden)

Ravneet S Vohra

Full Text Available The primary objectives of this study were to evaluate contractile and non-contractile content of lower leg muscles of boys with Duchenne muscular dystrophy (DMD and determine the relationships between non-contractile content and functional abilities.Lower leg muscles of thirty-two boys with DMD and sixteen age matched unaffected controls were imaged. Non-contractile content, contractile cross sectional area and non-contractile cross sectional area of lower leg muscles (tibialis anterior, extensor digitorum longus, peroneal, medial gastrocnemius and soleus were assessed by magnetic resonance imaging (MRI. Muscle strength, timed functional tests and the Brooke lower extremity score were also assessed.Non-contractile content of lower leg muscles (peroneal, medial gastrocnemius, and soleus was significantly greater than control group (p<0.05. Non-contractile content of lower leg muscles correlated with Brooke score (rs = 0.64-0.84 and 30 feet walk (rs = 0.66-0.80. Dorsiflexor (DF and plantarflexor (PF specific torque was significantly different between the groups.Overall, non-contractile content of the lower leg muscles was greater in DMD than controls. Furthermore, there was an age dependent increase in contractile content in the medial gastrocnemius of boys with DMD. The findings of this study suggest that T1 weighted MR images can be used to monitor disease progression and provide a quantitative estimate of contractile and non-contractile content of tissue in children with DMD.

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

Science.gov (United States)

Rodríguez-Vázquez, Jose Francisco; Honkura, Yohei; Katori, Yukio; Murakami, Gen; Abe, Hiroshi

2017-01-01

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. Copyright © 2016 Elsevier GmbH. All rights reserved.

Acylated and unacylated ghrelin do not directly stimulate glucose transport in isolated rodent skeletal muscle.

Science.gov (United States)

Cervone, Daniel T; Dyck, David J

2017-07-01

Emerging evidence implicates ghrelin, a gut-derived, orexigenic hormone, as a potential mediator of insulin-responsive peripheral tissue metabolism. However, in vitro and in vivo studies assessing ghrelin's direct influence on metabolism have been controversial, particularly due to confounding factors such as the secondary rise in growth hormone (GH) after ghrelin injection. Skeletal muscle is important in the insulin-stimulated clearance of glucose, and ghrelin's exponential rise prior to a meal could potentially facilitate this. This study was aimed at elucidating any direct stimulatory action that ghrelin may have on glucose transport and insulin signaling in isolated rat skeletal muscle, in the absence of confounding secondary factors. Oxidative soleus and glycolytic extensor digitorum longus skeletal muscles were isolated from male Sprague Dawley rats in the fed state and incubated with various concentrations of acylated and unacylated ghrelin in the presence or absence of insulin. Ghrelin did not stimulate glucose transport in either muscle type, with or without insulin. Moreover, GH had no acute, direct stimulatory effect on either basal or insulin-stimulated muscle glucose transport. In agreement with the lack of observed effect on glucose transport, ghrelin and GH also had no stimulatory effect on Ser 473 AKT or Thr 172 AMPK phosphorylation, two key signaling proteins involved in glucose transport. Furthermore, to our knowledge, we are among the first to show that ghrelin can act independent of its receptor and cause an increase in calmodulin-dependent protein kinase 2 (CaMKII) phosphorylation in glycolytic muscle, although this was not associated with an increase in glucose transport. We conclude that both acylated and unacylated ghrelin have no direct, acute influence on skeletal muscle glucose transport. Furthermore, the immediate rise in GH in response to ghrelin also does not appear to directly stimulate glucose transport in muscle. © 2017 The

Caffeine and contraction synergistically stimulate 5'-AMP-activated protein kinase and insulin-independent glucose transport in rat skeletal muscle.

Science.gov (United States)

Tsuda, Satoshi; Egawa, Tatsuro; Kitani, Kazuto; Oshima, Rieko; Ma, Xiao; Hayashi, Tatsuya

2015-10-01

5'-Adenosine monophosphate-activated protein kinase (AMPK) has been identified as a key mediator of contraction-stimulated insulin-independent glucose transport in skeletal muscle. Caffeine acutely stimulates AMPK in resting skeletal muscle, but it is unknown whether caffeine affects AMPK in contracting muscle. Isolated rat epitrochlearis muscle was preincubated and then incubated in the absence or presence of 3 mmol/L caffeine for 30 or 120 min. Electrical stimulation (ES) was used to evoke tetanic contractions during the last 10 min of the incubation period. The combination of caffeine plus contraction had additive effects on AMPKα Thr(172) phosphorylation, α-isoform-specific AMPK activity, and 3-O-methylglucose (3MG) transport. In contrast, caffeine inhibited basal and contraction-stimulated Akt Ser(473) phosphorylation. Caffeine significantly delayed muscle fatigue during contraction, and the combination of caffeine and contraction additively decreased ATP and phosphocreatine contents. Caffeine did not affect resting tension. Next, rats were given an intraperitoneal injection of caffeine (60 mg/kg body weight) or saline, and the extensor digitorum longus muscle was dissected 15 min later. ES of the sciatic nerve was performed to evoke tetanic contractions for 5 min before dissection. Similar to the findings from isolated muscles incubated in vitro, the combination of caffeine plus contraction in vivo had additive effects on AMPK phosphorylation, AMPK activity, and 3MG transport. Caffeine also inhibited basal and contraction-stimulated Akt phosphorylation in vivo. These findings suggest that caffeine and contraction synergistically stimulate AMPK activity and insulin-independent glucose transport, at least in part by decreasing muscle fatigue and thereby promoting energy consumption during contraction. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological

Targeted inhibition of TGF-β results in an initial improvement but long-term deficit in force production after contraction-induced skeletal muscle injury.

Science.gov (United States)

Gumucio, Jonathan P; Flood, Michael D; Phan, Anthony C; Brooks, Susan V; Mendias, Christopher L

2013-08-15

Transforming growth factor-β (TGF-β) is a proinflammatory cytokine that regulates the response of many tissues following injury. Previous studies in our lab have shown that treating muscles with TGF-β results in a dramatic accumulation of type I collagen, substantial fiber atrophy, and a marked decrease in force production. Because TGF-β promotes atrophy and fibrosis, our objective was to investigate whether the inhibition of TGF-β after injury would enhance the recovery of muscle following injury. We hypothesized that inhibiting TGF-β after contraction-induced injury would improve the functional recovery of muscles by preventing muscle fiber atrophy and weakness, and by limiting the accumulation of fibrotic scar tissue. To test this hypothesis, we induced an injury using a series of in situ lengthening contractions to extensor digitorum longus muscles of mice treated with either a bioneutralizing antibody against TGF-β or a sham antibody. Compared with controls, muscles from mice receiving TGF-β inhibitor showed a greater recovery in force 3 days and 7 days after injury but had a decrease in force compared with controls at the 21-day time point. The early enhancement in force in the TGF-β inhibitor group was associated with an initial improvement in tissue morphology, but, at 21 days, while the control group was fully recovered, the TGF-β inhibitor group displayed an irregular extracellular matrix and an increase in atrogin-1 gene expression. These results indicate that the inhibition of TGF-β promotes the early recovery of muscle function but is detrimental overall to full muscle recovery following moderate to severe muscle injuries.

Stenosing Tenosynovitis of the Flexor Hallucis Longus Tendon Associated with the Plantar Capsular Accessory Ossicle at the Interphalangeal Joint of the Great Toe

Directory of Open Access Journals (Sweden)

Song Ho Chang

2017-01-01

Full Text Available This report presents a case of stenosing tenosynovitis of the flexor hallucis longus tendon associated with the plantar capsular accessory ossicle at the interphalangeal joint of the great toe, which was confirmed by intraoperative observation and was successfully treated with surgical resection of the ossicle. As the plantar capsular accessory ossicle was not visible radiographically due to the lack of ossification, ultrasonography was helpful for diagnosing this disorder.

Effects of wide step walking on swing phase hip muscle forces and spatio-temporal gait parameters.

Science.gov (United States)

Bajelan, Soheil; Nagano, Hanatsu; Sparrow, Tony; Begg, Rezaul K

2017-07-01

Human walking can be viewed essentially as a continuum of anterior balance loss followed by a step that re-stabilizes balance. To secure balance an extended base of support can be assistive but healthy young adults tend to walk with relatively narrower steps compared to vulnerable populations (e.g. older adults and patients). It was, therefore, hypothesized that wide step walking may enhance dynamic balance at the cost of disturbed optimum coupling of muscle functions, leading to additional muscle work and associated reduction of gait economy. Young healthy adults may select relatively narrow steps for a more efficient gait. The current study focused on the effects of wide step walking on hip abductor and adductor muscles and spatio-temporal gait parameters. To this end, lower body kinematic data and ground reaction forces were obtained using an Optotrak motion capture system and AMTI force plates, respectively, while AnyBody software was employed for muscle force simulation. A single step of four healthy young male adults was captured during preferred walking and wide step walking. Based on preferred walking data, two parallel lines were drawn on the walkway to indicate 50% larger step width and participants targeted the lines with their heels as they walked. In addition to step width that defined walking conditions, other spatio-temporal gait parameters including step length, double support time and single support time were obtained. Average hip muscle forces during swing were modeled. Results showed that in wide step walking step length increased, Gluteus Minimus muscles were more active while Gracilis and Adductor Longus revealed considerably reduced forces. In conclusion, greater use of abductors and loss of adductor forces were found in wide step walking. Further validation is needed in future studies involving older adults and other pathological populations.

The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.

Science.gov (United States)

Hollingworth, S; Marshall, M W; Robson, E

1990-02-01

1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV.

IMAGE ANALYSIS IN GOMORI´S TRICHROME STAIN OF SKELETAL MUSCLES SUBJECTED TO ISCHEMIA AND REPERFUSION INJURY

Directory of Open Access Journals (Sweden)

Doris Haydee Rosero Salazar

2016-06-01

Full Text Available Conditions that produce ischemia and reperfusion injury include orthopedic surgeries, vascular diseases and accidents in remote places in which use of a manual tourniquet is required. Tissues under such stress suffer the consequences of evidenced by changes in their normal microscopic organization that can be reversible or irreversible according to the time and severity of lesion. An experimental model of ischemia has been designed taking into account the characteristics similar to a surgical procedure, from preparation for anesthesia up to the postsurgical follow up of each animal until it finishes the established time of reperfusion. Two muscles, soleus and extensor carpi radialis longus, dissected from Wistar rats that were underwent to short periods of ischemia and short and prolonged periods of reperfusion up to 32 days. There were no significant changes in the macroscopic weight of muscles, but significant differences were found in the area occupied by intramuscular extracellular matrix. During reperfusion, a partial recovery was observed until the last day of study. If we pretend to extrapolate these results to clinical areas, its importance focuses in the recovering of function and the following up of patients after surgical procedures as studied in the present experiment.

Determination of cable parameters in skeletal muscle fibres during repetitive firing of action potentials

Science.gov (United States)

Riisager, Anders; Duehmke, Rudy; Nielsen, Ole Bækgaard; Huang, Christopher L; Pedersen, Thomas Holm

2014-01-01

Recent studies in rat muscle fibres show that repetitive firing of action potentials causes changes in fibre resting membrane conductance (Gm) that reflect regulation of ClC-1 Cl− and KATP K+ ion channels. Methodologically, these findings were obtained by inserting two microelectrodes at close proximity in the same fibres enabling measurements of fibre input resistance (Rin) in between action potential trains. Since the fibre length constant (λ) could not be determined, however, the calculation of Gm relied on the assumptions that the specific cytosolic resistivity (Ri) and muscle fibre volume remained constant during the repeated action potential firing. Here we present a three-microelectrode technique that enables determinations of multiple cable parameters in action potential-firing fibres including Rin and λ as well as waveform and conduction velocities of fully propagating action potentials. It is shown that in both rat and mouse extensor digitorum longus (EDL) fibres, action potential firing leads to substantial changes in both muscle fibre volume and Ri. The analysis also showed, however, that regardless of these changes, rat and mouse EDL fibres both exhibited initial decreases in Gm that were eventually followed by a ∼3-fold, fully reversible increase in Gm after the firing of 1450–1800 action potentials. Using this three-electrode method we further show that the latter rise in Gm was closely associated with excitation failures and loss of action potential signal above −20 mV. PMID:25128573

Cold exposure increases slow-type myosin heavy chain 1 (MyHC1) composition of soleus muscle in rats.

Science.gov (United States)

Mizunoya, Wataru; Iwamoto, Yohei; Sato, Yusuke; Tatsumi, Ryuichi; Ikeuchi, Yoshihide

2014-03-01

The aim of this study was to examine the effects of cold exposure on rat skeletal muscle fiber type, according to myosin heavy chain (MyHC) isoform and metabolism-related factors. Male Wistar rats (7 weeks old) were housed individually at 4 ± 2°C as a cold-exposed group or at room temperature (22 ± 2°C) as a control group for 4 weeks. We found that cold exposure significantly increased the slow-type MyHC1 content in the soleus muscle (a typical slow-type fiber), while the intermediate-type MyHC2A content was significantly decreased. In contrast to soleus, MyHC composition of extensor digitorum longus (EDL, a typical fast-type fiber) and gastrocnemius (a mix of slow-type and fast-type fibers) muscle did not change from cold exposure. Cold exposure increased mRNA expression of mitochondrial uncoupling protein 3 (UCP3) in both the soleus and EDL. Cold exposure also increased mRNA expression of myoglobin, peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) and forkhead box O1 (FOXO1) in the soleus. Upregulation of UCP3 and PGC1α proteins were observed with Western blotting in the gastrocnemius. Thus, cold exposure increased metabolism-related factors in all muscle types that were tested, but MyHC isoforms changed only in the soleus. © 2013 Japanese Society of Animal Science.

Intracellular uptake and degradation of extracellular tracers in mouse skeletal muscle in vitro: the effect of denervation

Energy Technology Data Exchange (ETDEWEB)

Libelius, R; Lundquist, I; Templeton, W; Thesleff, S [Lund Univ. (Sweden)

1978-01-01

Innervated and chronically denervated mouse skeletal muscles have been incubated under various conditions in a Ringer solution containing one of the three macromolecules (/sup 3/H) ..cap alpha..-neurotoxin, (/sup 3/H)inulin and horseradish peroxidase. Following extensive wash-out for 4 h of the extracellular compartment, the amount of each macromolecule retained intracellularly was obtained. Intracellular uptake of a (/sup 3/H)monoacetylated ..cap alpha..-neurotoxin in vitro at 37 C was found to be increased in denervated mouse extensor digitorum longus muscles compared to innervated control muscles. Similarly, the uptake in vitro at 37 C of (/sup 3/H) inulin and horseradish peroxidase was also increased in denervated muscles. At 4 C the uptake of (/sup 3/H)inulin and horseradish peroxidase was markedly reduced. Protamine was found to stimulate the uptake of (/sup 3/H)inulin at 37 C, but not at 4 C. Reduction in specific activity by addition of 50-fold excess of unlabelled inulin failed to affect the uptake of (/sup 3/H)inulin suggesting that this uptake process obeyed bulk kinetics. Furthermore, the endocytized (/sup 3/H)inulin was found to be strongly retained in the muscles since prolonged washing or addition of unlabelled inulin to the washing solution did not reduce the uptake. Characterization of (/sup 3/H)inulin taken up by the muscles was performed by gel chromatography on Sephadex G-25. Using a purified (/sup 3/H)inulin solution it was observed that about 45% of the total radioactivity remaining in the muscles was eluted as (/sup 3/H)inulin. Additional radioactivity consisted of lower molecular weight compounds. Degradation products of (/sup 3/H)inulin were only present in the muscle homogenate and were not detected in the incubation solution. Results suggest that intracellular uptake of different macromolecules by endocytosis in skeletal muscles increases following denervation, and that following uptake, degradation of the endocytized material may occur.

High lateral plantar pressure is related to an increased tibialis anterior/fibularis longus activity ratio in patients with recurrent lateral ankle sprain

Directory of Open Access Journals (Sweden)

Mineta S

2017-06-01

Full Text Available Shinshiro Mineta,1 Takayuki Inami,2 Raldy Mariano,3 Norikazu Hirose4 1Graduate School of Sport Sciences, 2Institute of Physical Education, Keio University, Hiyoshi, Yokohama, 3Graduate School of Asia-Pacific Studies, Waseda University, Shinjuku, Tokyo, 4Faculty of Sport Sciences, Waseda University, Higashifushimi, Nishitokyo, Japan Introduction: Center of pressure (COP is a sudden displacement at the time of a lateral ankle sprain (LAS. It has been suggested that the distribution of plantar pressure and the quantity of COP displacement are important for assessing the risk of LAS. Therefore, we evaluated the plantar pressure during a single-leg balance test with eyes closed (SLB-C to identify the factors and characteristics of plantar pressure in people with repeated cases of LAS.Methods: We recruited 22 collegiate athletes and divided them into an instability group (IG; n=11 and a control group (CG; n=11. We measured the distribution of plantar pressure and lower extremity muscle activity during a SLB-C along with static alignment and isometric ankle strength.Results: The fibularis longus (FL activity was significantly lower in the IG than in the CG. The lateral plantar pressure (LPP/medial plantar pressure (MPP ratio was also higher in the IG than in the CG. In addition, the LPP/MPP ratio was correlated with the tibialis anterior (TA/FL ratio.Conclusion: These results suggest that increased lateral plantar pressure is related to decreased FL activity and increased TA/FL ratio. Keywords: chronic ankle instability, ankle sprain, postural stability, soccer, prevention

Bilateral Posterior Tibial Tendon and Flexor Digitorum Longus Dislocations.

Science.gov (United States)

Padegimas, Eric M; Beck, David M; Pedowitz, David I

2017-04-01

The authors present a case of a previously healthy and athletic 17-year-old female who presented with a 3.5-year history of medial left ankle pain after sustaining an inversion injury while playing basketball. Prior to presentation, she had failed prior immobilization and physical therapy for a presumed ankles sprain. Physical examination revealed a dislocated posterior tibial tendon (PTT) that was temporarily reducible, but would spontaneously dislocate immediately after reduction. She had pain and snapping of the PTT with resisted ankle plantar flexion and resisted inversion as well as 4/5 strength in ankle inversion. The diagnosis of dislocated PTT was confirmed on magnetic resonance imaging (MRI). The patient underwent suture anchor repair of the medial retinaculum of the left ankle. At the time of surgery both the PTT and flexor digitorum longus (FDL) were dislocated. Three months postoperatively, the patient represented with PTT dislocation of the right (nonoperative) ankle confirmed by MRI. After failure of immobilization, physical therapy, and oral anti-inflammatory medications, the patient underwent suture anchor repair of the medial retinaculum of the right ankle. At 6 months postoperatively, the patient has 5/5 strength inversion bilaterally, no subluxation of either PTT, and has returned to all activities without limitation. The authors present this unique case of bilateral PTT dislocation and concurrent PTT/FDL dislocation along with review of the literature for PTT dislocation. The authors highlight the common misdaiganosis of this injury and highlight the successful results of surgical intervention. Level V: Case report.

Na+,K+-pump stimulation improves contractility in isolated muscles of mice with hyperkalemic periodic paralysis.

Science.gov (United States)

Clausen, Torben; Nielsen, Ole Bækgaard; Clausen, Johannes D; Pedersen, Thomas Holm; Hayward, Lawrence J

2011-07-01

In patients with hyperkalemic periodic paralysis (HyperKPP), attacks of muscle weakness or paralysis are triggered by K(+) ingestion or rest after exercise. Force can be restored by muscle work or treatment with β(2)-adrenoceptor agonists. A missense substitution corresponding to a mutation in the skeletal muscle voltage-gated Na(+) channel (Na(v)1.4, Met1592Val) causing human HyperKPP was targeted into the mouse SCN4A gene (mutants). In soleus muscles prepared from these mutant mice, twitch, tetanic force, and endurance were markedly reduced compared with soleus from wild type (WT), reflecting impaired excitability. In mutant soleus, contractility was considerably more sensitive than WT soleus to inhibition by elevated [K(+)](o). In resting mutant soleus, tetrodotoxin (TTX)-suppressible (22)Na uptake and [Na(+)](i) were increased by 470 and 58%, respectively, and membrane potential was depolarized (by 16 mV, P Na(+),K(+) pump-mediated (86)Rb uptake was 83% larger than in WT. Salbutamol stimulated (86)Rb uptake and reduced [Na(+)](i) both in mutant and WT soleus. Stimulating Na(+),K(+) pumps with salbutamol restored force in mutant soleus and extensor digitorum longus (EDL). Increasing [Na(+)](i) with monensin also restored force in soleus. In soleus, EDL, and tibialis anterior muscles of mutant mice, the content of Na(+),K(+) pumps was 28, 62, and 33% higher than in WT, respectively, possibly reflecting the stimulating effect of elevated [Na(+)](i) on the synthesis of Na(+),K(+) pumps. The results confirm that the functional disorders of skeletal muscles in HyperKPP are secondary to increased Na(+) influx and show that contractility can be restored by acute stimulation of the Na(+),K(+) pumps. Calcitonin gene-related peptide (CGRP) restored force in mutant soleus but caused no detectable increase in (86)Rb uptake. Repeated excitation and capsaicin also restored contractility, possibly because of the release of endogenous CGRP from nerve endings in the isolated

Skeletal muscle, but not cardiovascular function, is altered in a mouse model of autosomal recessive hypophosphatemic rickets

Directory of Open Access Journals (Sweden)

Michael J. Wacker

2016-05-01

Full Text Available Autosomal recessive hypophosphatemic rickets (ARHR is a heritable disorder characterized by hypophosphatemia, osteomalacia, and poor bone development. ARHR results from inactivating mutations in the DMP1 gene with the human phenotype being recapitulated in the Dmp1 null mouse model which displays elevated plasma fibroblast growth factor 23. While the bone phenotype has been well characterized, it is not known what effects ARHR may also have on skeletal, cardiac, or vascular smooth muscle function, which is critical to understand to treat patients suffering from this condition. In this study, the extensor digitorum longus (EDL- fast-twitch muscle, soleus (SOL- slow-twitch muscle, heart, and aorta were removed from Dmp1 null mice and ex-vivo functional tests were simultaneously performed in collaboration by three different laboratories. Dmp1 null EDL and SOL muscles produced less force than wildtype muscles after normalization for physiological cross sectional area of the muscles. Both EDL and SOL muscles from Dmp1 null mice also produced less force after the addition of caffeine (which releases calcium from the sarcoplasmic reticulum which may indicate problems in excitation contraction coupling in these mice. While the body weights of the Dmp1 null were smaller than wildtype, the heart weight to body weight ratio was higher. However, there were no differences in pathological hypertrophic gene expression compared to wildtype and maximal force of contraction was not different indicating that there may not be cardiac pathology under the tested conditions. We did observe a decrease in the rate of force development generated by cardiac muscle in the Dmp1 null which may be related to some of the deficits observed in skeletal muscle. There were no differences observed in aortic contractions induced by PGF2a or 5-HT or in endothelium-mediated acetylcholine-induced relaxations or endothelium-independent sodium nitroprusside-induced relaxations. In

Transposition of branches of radial nerve innervating supinator to posterior interosseous nerve for functional reconstruction of finger and thumb extension in 4 patients with middle and lower trunk root avulsion injuries of brachial plexus.

Science.gov (United States)

Wu, Xia; Cong, Xiao-Bing; Huang, Qi-Shun; Ai, Fang-Xin; Liu, Yu-Tian; Lu, Xiao-Cheng; Li, Jin; Weng, Yu-Xiong; Chen, Zhen-Bing

2017-12-01

This study aimed to investigate the reconstruction of the thumb and finger extension function in patients with middle and lower trunk root avulsion injuries of the brachial plexus. From April 2010 to January 2015, we enrolled in this study 4 patients diagnosed with middle and lower trunk root avulsion injuries of the brachial plexus via imaging tests, electrophysiological examinations, and clinical confirmation. Muscular branches of the radial nerve, which innervate the supinator in the forearm, were transposed to the posterior interosseous nerve to reconstruct the thumb and finger extension function. Electrophysiological findings and muscle strength of the extensor pollicis longus and extensor digitorum communis, as well as the distance between the thumb tip and index finger tip, were monitored. All patients were followed up for 24 to 30 months, with an average of 27.5 months. Motor unit potentials (MUP) of the extensor digitorum communis appeared at an average of 3.8 months, while MUP of the extensor pollicis longus appeared at an average of 7 months. Compound muscle action potential (CMAP) appeared at an average of 9 months in the extensor digitorum communis, and 12 months in the extensor pollicis longus. Furthermore, the muscle strength of the extensor pollicis longus and extensor digitorum communis both reached grade III at 21 months. Lastly, the average distance between the thumb tip and index finger tip was 8.8 cm at 21 months. In conclusion, for patients with middle and lower trunk injuries of the brachial plexus, transposition of the muscular branches of the radial nerve innervating the supinator to the posterior interosseous nerve for the reconstruction of thumb and finger extension function is practicable and feasible.

Hydrogen peroxide modulates Ca2+-activation of single permeabilized fibres from fast- and slow-twitch skeletal muscles of rats.

Science.gov (United States)

Plant, D R; Lynch, G S; Williams, D A

2000-01-01

We examined the effects of redox modulation on single membrane-permeabilized fibre segments from the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles of adult rats to determine whether the contractile apparatus was the redox target responsible for the increased contractility of muscles exposed to low concentrations of H2O2. The effects of H2O2 on maximum Ca2+-activated force were dose-dependent with 30 min exposure to 5 mM H2O2 causing a progressive decrease by 22+/-3 and 13+/-2% in soleus and EDL permeabilized muscle fibres, respectively. Lower concentrations of exogenous H2O2 (100 microM and 1 mM) had no effect on maximum Ca2+-activated force. Subsequent exposure to the reductant dithiothreitol (DTT, 10 mM, 10 min) fully reversed the H2O2-induced depression of force in EDL, but not in soleus muscle fibres. Incubation with DTT alone for 10 min did not alter Ca2+-activated force in either soleus or EDL muscle fibres. The sensitivity of the contractile filaments to Ca2+ (pCa50) was not altered by exposure to any concentration of exogenous H2O2. However, all concentrations of H2O2 diminished the Hill coefficient in permeabilized fibres from the EDL muscle, indicating that the cooperativity of Ca2+ binding to troponin is altered. H2O2 (5 mM) did not affect rigor force, which indicates that the number of crossbridges participating in contraction was not reduced. In conclusion, H2O2 may reduce the maximum Ca2+ activated force production in skinned muscle fibres by decreasing the force per crossbridge.

Actin Nemaline Myopathy Mouse Reproduces Disease, Suggests Other Actin Disease Phenotypes and Provides Cautionary Note on Muscle Transgene Expression

Science.gov (United States)

Ravenscroft, Gianina; Jackaman, Connie; Sewry, Caroline A.; McNamara, Elyshia; Squire, Sarah E.; Potter, Allyson C.; Papadimitriou, John; Griffiths, Lisa M.; Bakker, Anthony J.; Davies, Kay E.; Laing, Nigel G.; Nowak, Kristen J.

2011-01-01

Mutations in the skeletal muscle α-actin gene (ACTA1) cause congenital myopathies including nemaline myopathy, actin aggregate myopathy and rod-core disease. The majority of patients with ACTA1 mutations have severe hypotonia and do not survive beyond the age of one. A transgenic mouse model was generated expressing an autosomal dominant mutant (D286G) of ACTA1 (identified in a severe nemaline myopathy patient) fused with EGFP. Nemaline bodies were observed in multiple skeletal muscles, with serial sections showing these correlated to aggregates of the mutant skeletal muscle α-actin-EGFP. Isolated extensor digitorum longus and soleus muscles were significantly weaker than wild-type (WT) muscle at 4 weeks of age, coinciding with the peak in structural lesions. These 4 week-old mice were ∼30% less active on voluntary running wheels than WT mice. The α-actin-EGFP protein clearly demonstrated that the transgene was expressed equally in all myosin heavy chain (MHC) fibre types during the early postnatal period, but subsequently became largely confined to MHCIIB fibres. Ringbinden fibres, internal nuclei and myofibrillar myopathy pathologies, not typical features in nemaline myopathy or patients with ACTA1 mutations, were frequently observed. Ringbinden were found in fast fibre predominant muscles of adult mice and were exclusively MHCIIB-positive fibres. Thus, this mouse model presents a reliable model for the investigation of the pathobiology of nemaline body formation and muscle weakness and for evaluation of potential therapeutic interventions. The occurrence of core-like regions, internal nuclei and ringbinden will allow analysis of the mechanisms underlying these lesions. The occurrence of ringbinden and features of myofibrillar myopathy in this mouse model of ACTA1 disease suggests that patients with these pathologies and no genetic explanation should be screened for ACTA1 mutations. PMID:22174871

Calcific retropharyngeal tendinitis. [Radiological findings

Energy Technology Data Exchange (ETDEWEB)

Karasick, D.; Karasick, S.

1981-12-01

Calcific retropharyngeal tendinitis is an imflammation of the longus colli muscle tendon which is located on the anterior surface of the verterbral column extending from the atlas to the third thoracic vertebra. The acute inflammatory condition is selflimiting with symptoms consisting of a gradually increasing neck pain often associated with throat pain and difficulty swallowing. The pain is aggravated by head and neck movement. Clinically the condition can be confused with retropharyngeal absecess, meningitis, infectious spondylitis, and post-traumatic muscle spasm. The radiographic features of this condition consist of pre-vertebral soft tissue swelling from C1 to C4 and amorphous calcific density in the longus colli tendon anterior to the body of C2 and inferior to the anterior arch of C1.

Calcific retropharyngeal tendinitis

International Nuclear Information System (INIS)

Karasick, D.; Karasick, S.

1981-01-01

Calcific retropharyngeal tendinitis is an imflammation of the longus colli muscle tendon which is located on the anterior surface of the verterbral column extending from the atlas to the third thoracic vertebra. The acute inflammatory condition is selflimiting with symptoms consisting of a gradually increasing neck pain often associated with throat pain and difficulty swallowing. The pain is aggravated by head and neck movement. Clinically the condition can be confused with retropharyngeal absecess, meningitis, infectious spondylitis, and post-traumatic muscle spasm. The radiographic features of this condition consist of pre-vertebral soft tissue swelling from C1 to C4 and amorphous calcific density in the longus colli tendon anterior to the body of C2 and inferior to the anterior arch of C1. (orig.)

Initiating running barefoot: Effects on muscle activation and impact accelerations in habitually rearfoot shod runners.

Science.gov (United States)

Lucas-Cuevas, Angel Gabriel; Priego Quesada, José Ignacio; Giménez, José Vicente; Aparicio, Inma; Jimenez-Perez, Irene; Pérez-Soriano, Pedro

2016-11-01

Runners tend to shift from a rearfoot to a forefoot strike pattern when running barefoot. However, it is unclear how the first attempts at running barefoot affect habitually rearfoot shod runners. Due to the inconsistency of their recently adopted barefoot technique, a number of new barefoot-related running injuries are emerging among novice barefoot runners. The aim of this study was therefore to analyse the influence of three running conditions (natural barefoot [BF], barefoot with a forced rearfoot strike [BRS], and shod [SH]) on muscle activity and impact accelerations in habitually rearfoot shod runners. Twenty-two participants ran at 60% of their maximal aerobic speed while foot strike, tibial and head impact accelerations, and tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle activity were registered. Only 68% of the runners adopted a non-rearfoot strike pattern during BF. Running BF led to a reduction of TA activity as well as to an increase of GL and GM activity compared to BRS and SH. Furthermore, BRS increased tibial peak acceleration, tibial magnitude and tibial acceleration rate compared to SH and BF. In conclusion, 32% of our runners showed a rearfoot strike pattern at the first attempts at running barefoot, which corresponds to a running style (BRS) that led to increased muscle activation and impact accelerations and thereby to a potentially higher risk of injury compared to running shod.

Sarcomere length-dependence of activity-dependent twitch potentiation in mouse skeletal muscle

Directory of Open Access Journals (Sweden)

MacIntosh Brian R

2002-12-01

Full Text Available Abstract Background It has been reported that potentiation of a skeletal muscle twitch response is proportional to muscle length with a negative slope during staircase, and a positive slope during posttetanic potentiation. This study was done to directly compare staircase and posttetanic responses with measurement of sarcomere length to compare their length-dependence. Methods Mouse extensor digitorum longus (EDL muscles were dissected to small bundles of fibers, which permit measurement of sarcomere length (SL, by laser diffraction. In vitro fixed-end contractions of EDL fiber bundles were elicited at 22°C and 35°C at sarcomere lengths ranging from 2.35 μm to 3.85 μm. Twitch contractions were assessed before and after 1.5 s of 75 Hz stimulation at 22°C or during 10 s of 10 Hz stimulation at 22°C or 35°C. Results Staircase potentiation was greater at 35°C than 22°C, and the relative magnitude of the twitch contraction (Pt*/Pt was proportional to sarcomere length with a negative slope, over the range 2.3 μm – 3.7 μm. Linear regression yielded the following: Pt*/Pt = -0.59·SL+3.27 (r2 = 0.74; Pt*/Pt = -0.39·SL+2.34 (r2 = 0.48; and Pt*/Pt = -0.50·SL+2.45 (r2 = 0.80 for staircase at 35°C, and 22°C and posttetanic response respectively. Posttetanic depression rather than potentiation was present at long SL. This indicates that there may be two processes operating in these muscles to modulate the force: one that enhances and a second that depresses the force. Either or both of these processes may have a length-dependence of its mechanism. Conclusion There is no evidence that posttetanic potentiation is fundamentally different from staircase in these muscles.

Effects of acute exposure of heavy ion to spinal cord on the properties of motoneurons and muscle fibers in rats

International Nuclear Information System (INIS)

Ishihara, Akihiko; Ohira, Yoshinobu; Kawano, Norifumi; Nagaoka, Shunji; Nojima, Kumie

2003-01-01

We investigate effects of localized exposure of heavy ion to the lumbar 4th to 6th segments of the rat spinal cord on the properties of motoneurons and the innervated muscle fibers without surgical treatments. Twenty 7-week-old male Wistar rats were exposed to 5 mm spread-out Bragg peak (SOBP) carbon beam (290 MeV, linear energy transfer (LET)=130 keV/μm): Two doses (15 Gy or 20 Gy) were applied to each group of rats (n=5) in two different depths; one group was exposed only for ventral horn of the spinal cord while other for whole spinal cord. Five rats served as controls. The rats were exposed to carbon irons on October 26, 2002. We will sacrifice the rats soon after they show an abnormal behavior including posture and walking. Cell body size and oxidative enzyme activity of spinal motoneurons of the control and heavy-ion-exposed rats will be analyzed. In addition, cell size, oxidative enzyme activity, and expressions of myosin heavy chain isoforms of the gastrocnemius, soleus, plantaris, extensor digitorum longus, and tibialis anterior muscle fibers will be also determined. This study is performed to test our hypothesis that atrophy and a decrease in cross-sectional area of motoneurons and muscle fibers which they innervate, as well as a decrease in oxidative activity of motoneurons and muscle fibers, will be induced due to exposure to heavy ion. (author)

Rehabilitation and Return to Sport Following Surgical Repair of the Rectus Abdominis and Adductor Longus in a Professional Basketball Player: A Case Report.

Science.gov (United States)

Short, Steven M; Anloague, Philip A; Strack, Donald S

2016-08-01

Study Design Case report. Background Acute traumatic avulsion of the rectus abdominis and adductor longus is rare. Chronic groin injuries, often falling under the athletic pubalgia spectrum, have been reported to be more common. There is limited evidence detailing the comprehensive rehabilitation and return to sport of an athlete following surgical or conservative treatment of avulsion injuries of the pubis or other sports-related groin pathologies. Case Description A 29-year-old National Basketball Association player sustained a contact injury during a professional basketball game. This case report describes a unique clinical situation specific to professional sport, in which a surgical repair of an avulsed rectus abdominis and adductor longus was combined with a multimodal impairment- and outcomes-based rehabilitation program. Outcomes The patient returned to in-season competition at 5 weeks postoperation. Objective measures were tracked throughout rehabilitation and compared to baseline assessments. Measures such as the Copenhagen Hip and Groin Outcome Score and numeric pain-rating scale revealed progress beyond the minimal important difference. Discussion This case report details the clinical reasoning and evidence-informed interventions involved in the return to elite sport. Detailed programming and objective assessment may assist in achieving desired outcomes ahead of previously established timelines. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2016;46(8):697-706. Epub 3 Jul 2016. doi:10.2519/jospt.2016.6352.

Response of mef2 Gene of Slow and Fast Twitch Muscles of Wistar Male Rats to One Bout of Resistance Exercise

Directory of Open Access Journals (Sweden)

M Fathi

2016-11-01

Full Text Available Introduction: Myocyte Enhancer Factor 2 (mef2 gene relates with multiple myogenic transcriptional factors that induces activation Muscle-specific genes. MEF2 contributes in muscular cells development and differentiation as well as in fibers transition in response to stimulants. Therefore, the aim of this study was to evaluate the effect of one bout of resistance exercise (RE on mef2 gene expression in fast and slow skeletal muscles of Wistar male rats. Methods: For this experimental study, 15 rats from Pasteur Institute were prepared and housed under natural conditions (temperature, light/dark (12:12 cycle, with ad libitum access to food and water and then randomly divided assigned to RE (n=10 and control groups (n=5; the RE group performed one RE session. 3 and 6 hours following, the rats were anaesthetized and sacrificed, then the soleus and Extensor digitorum longus (EDL muscles were removed. determine mef2 gene expression rate, the Quantitative Real time RT-PCR was used. Data were analyzed by one sample and independent samples t test. Results: In EDL muscle, in response to one RE session, the mef2 gene expression increased non significantly at 3 hour (p=0/093 and increased significantly (p=/008 at 6 hour after exercise, but in soleus muscle, the mef2 gene expression decreased significantly at 3 hour (p=0/01, and at 6 hour after RE session there was no observed significant change (p=0.247. Conclusion: Mef2 expression gene is differently changes in muscle fibers, which are likely associated with changes in fiber type in response to resistance exercise.

Impaired sarcoplasmic reticulum Ca(2+) release rate after fatiguing stimulation in rat skeletal muscle

DEFF Research Database (Denmark)

Ørtenblad, Niels; Sjøgaard, G; Madsen, Klavs

2000-01-01

during the first 0.5-1 h the metabolic state recovered to resting levels, and a slow phase from 1-3 h characterized by a rather slow recovery of the mechanical properties. The recovery of SR Ca(2+) release rate was closely correlated to +dF/dt during the slow phase of recovery (r(2) = 0.51; P ... to 66% that persisted for 1 h, followed by a gradual recovery to 87% of prefatigue release rate at 3 h recovery. Tetanic force and rate of force development (+dF/dt) and relaxation (-dF/dt) were depressed by approximately 80% after stimulation. Recovery occurred in two phases: an initial phase, in which......The purpose of the study was to characterize the sarcoplasmic reticulum (SR) function and contractile properties before and during recovery from fatigue in the rat extensor digitorum longus muscle. Fatiguing contractions (60 Hz, 150 ms/s for 4 min) induced a reduction of the SR Ca(2+) release rate...

β-adrenergic ([3H] CGP-12177) receptors are elevated in slices of soleus muscle from CHF 147 dystrophic hamsters

International Nuclear Information System (INIS)

Watson-Wright, W.M.; Wilkinson, M.

1987-01-01

The authors utilized a muscle slice technique to compare the ontogeny of cell surface β-adrenergic receptor binding in soleus and extensor digitorum longus (EDL) muscles of male Golden Syrian (GS) and Canadian Hybrid Farms 147 (CHF 147) dystrophic hamsters. Binding of the β-adrenergic antagonist, [ 3 H] CGP-12177 (CGP), to GS muscle slices was reversible, saturable, stereospecific and of high affinity. Bmax was higher in the soleus (2.57+/-.12 fmol/mg wet wt) than in the EDL (1.61+/-.17 fmol/mg wet wt) of adult animals while affinities were similar (0.35+/-.06 and 0.24+/-.04 nM respectively). No differences in binding characteristics were seen in EDL of GS compared to CHF 147 animals. In soleus slices from GS hamsters, Bmax was highest at 16 days of age (5.72+/-0.26 fmol/mg), decreased between 16 and 29 days and remained constant until 300 days (2.51+/-0.52 fmol/mg). In dystrophic soleus slices, Bmax was also higher at 16 days than at any other age but receptor number decreased gradually, remaining higher than in GS until 90 days of age (p<0.05). The failure of β-adrenergic receptor number to decrease at a normal rate may be implicated in the pathogenesis of hamster polymyopathy. 21 references, 5 figures, 1 table

Effects of Endurance Training on A12 Acetyl Cholinesterase Activity in Fast and Slow-Twitch Skeletal Muscles of Male Wistar Rats

Directory of Open Access Journals (Sweden)

Ali Gorzi

2013-10-01

Full Text Available Background: Endurance training improves the activity of G4 type acetylcholine esterase (AchE in muscle fibres. The purpose of this study was to investigate the effects of 8 weeks of endurance training (ET on activity of A12 type of AchE in Flexor Hallucis Longus (FHL and Soleus (SOL muscles of rats. Materials and Methods: 16 male wistar rats (age: 10 weeks and weight: 172.17±10.080 gr, were randomly divided in 2 groups (control; N=8 and ET; N=8. Training group carried out 8 weeks (5 session/week of endurance training on animal treadmill with speed of 10 m/min for 30 min at the first week which was gradually increased to 30 m/min for 60 min (70-80% of VO2max at the last week. Forty eight hours after last session of training, FHL and Sol muscles of animals were moved out under sterilized situation by cutting on posterio-lateral side of hind limb. For separating AchE subunits, homogenization and electrophoresis (0.06 non-denaturaing polyacrilamide methods were used. AchE activity was measured by Elisa kit.Results: The activity of this protein significantly (p=0.017 increased in SOL muscle of ET group by 119%, but did not changed in FHL. In both groups (ET and Con, FHL muscle had significantly (ET: p=0.028 and Con p=0.01 higher basic levels of AchE activity compared to SOL muscle. This significant increase in AchE of SOL might be indicative of responsiveness of AchE of this muscle following endurance training for improving acetylcholine (Ach cycle in neuromuscular junction.Conclusion: Endurance training might increase the A12 type AchE activity to improve the Ach cycle as part of the adaptation of neuromuscular junction to increased level of physical activity.

Isolated avulsion fracture of the first metatarsal base at the peroneus longus tendon attachment: a case report.

Science.gov (United States)

Weinberg, Maxwell W; Krähenbühl, Nicola; Davidson, Nathan P; Hanrahan, Christopher J; Barg, Alexej

2018-05-01

Avulsion fractures of the first metatarsal (MT1) base at the peroneus longus (PL) tendon attachment are rare and may be undiagnosed during an emergency visit. If the injury is not treated properly, chronic pain or persistent impairment for inversion and plantar-flexion of the first ray may occur. This case report presents a 30-year-old woman who presented 10 weeks post trauma to a foot and ankle surgeon due to a swollen right midfoot with diffuse tenderness over the medial Lisfranc joint. Further evaluation showed an isolated avulsion fracture of the first metatarsal, which was undiagnosed during the emergent visit following the accident. In this case, the patient was successfully treated conservatively. The goal of this article is to raise awareness of this rare injury for radiologists and orthopedic surgeons.

Coordinated balancing of muscle oxidative metabolism through PGC-1{alpha} increases metabolic flexibility and preserves insulin sensitivity

Energy Technology Data Exchange (ETDEWEB)

Summermatter, Serge [Biozentrum, Division of Pharmacology/Neurobiology, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel (Switzerland); Troxler, Heinz [Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University Children' s Hospital, University of Zurich, Steinwiesstrasse 75, CH-8032 Zurich (Switzerland); Santos, Gesa [Biozentrum, Division of Pharmacology/Neurobiology, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel (Switzerland); Handschin, Christoph, E-mail: christoph.handschin@unibas.ch [Biozentrum, Division of Pharmacology/Neurobiology, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel (Switzerland)

2011-04-29

Highlights: {yields} PGC-1{alpha} enhances muscle oxidative capacity. {yields} PGC-1{alpha} promotes concomitantly positive and negative regulators of lipid oxidation. {yields} Regulator abundance enhances metabolic flexibility and balances oxidative metabolism. {yields} Balanced oxidation prevents detrimental acylcarnitine and ROS generation. {yields} Absence of detrimental metabolites preserves insulin sensitivity -- Abstract: The peroxisome proliferator-activated receptor {gamma} coactivator 1{alpha} (PGC-1{alpha}) enhances oxidative metabolism in skeletal muscle. Excessive lipid oxidation and electron transport chain activity can, however, lead to the accumulation of harmful metabolites and impair glucose homeostasis. Here, we investigated the effect of over-expression of PGC-1{alpha} on metabolic control and generation of insulin desensitizing agents in extensor digitorum longus (EDL), a muscle that exhibits low levels of PGC-1{alpha} in the untrained state and minimally relies on oxidative metabolism. We demonstrate that PGC-1{alpha} induces a strictly balanced substrate oxidation in EDL by concomitantly promoting the transcription of activators and inhibitors of lipid oxidation. Moreover, we show that PGC-1{alpha} enhances the potential to uncouple oxidative phosphorylation. Thereby, PGC-1{alpha} boosts elevated, yet tightly regulated oxidative metabolism devoid of side products that are detrimental for glucose homeostasis. Accordingly, PI3K activity, an early phase marker for insulin resistance, is preserved in EDL muscle. Our findings suggest that PGC-1{alpha} coordinately coactivates the simultaneous transcription of gene clusters implicated in the positive and negative regulation of oxidative metabolism and thereby increases metabolic flexibility. Thus, in mice fed a normal chow diet, over-expression of PGC-1{alpha} does not alter insulin sensitivity and the metabolic adaptations elicited by PGC-1{alpha} mimic the beneficial effects of endurance training

Coordinated balancing of muscle oxidative metabolism through PGC-1α increases metabolic flexibility and preserves insulin sensitivity

International Nuclear Information System (INIS)

Summermatter, Serge; Troxler, Heinz; Santos, Gesa; Handschin, Christoph

2011-01-01

Highlights: → PGC-1α enhances muscle oxidative capacity. → PGC-1α promotes concomitantly positive and negative regulators of lipid oxidation. → Regulator abundance enhances metabolic flexibility and balances oxidative metabolism. → Balanced oxidation prevents detrimental acylcarnitine and ROS generation. → Absence of detrimental metabolites preserves insulin sensitivity -- Abstract: The peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) enhances oxidative metabolism in skeletal muscle. Excessive lipid oxidation and electron transport chain activity can, however, lead to the accumulation of harmful metabolites and impair glucose homeostasis. Here, we investigated the effect of over-expression of PGC-1α on metabolic control and generation of insulin desensitizing agents in extensor digitorum longus (EDL), a muscle that exhibits low levels of PGC-1α in the untrained state and minimally relies on oxidative metabolism. We demonstrate that PGC-1α induces a strictly balanced substrate oxidation in EDL by concomitantly promoting the transcription of activators and inhibitors of lipid oxidation. Moreover, we show that PGC-1α enhances the potential to uncouple oxidative phosphorylation. Thereby, PGC-1α boosts elevated, yet tightly regulated oxidative metabolism devoid of side products that are detrimental for glucose homeostasis. Accordingly, PI3K activity, an early phase marker for insulin resistance, is preserved in EDL muscle. Our findings suggest that PGC-1α coordinately coactivates the simultaneous transcription of gene clusters implicated in the positive and negative regulation of oxidative metabolism and thereby increases metabolic flexibility. Thus, in mice fed a normal chow diet, over-expression of PGC-1α does not alter insulin sensitivity and the metabolic adaptations elicited by PGC-1α mimic the beneficial effects of endurance training on muscle metabolism in this context.

Evidence that the Na+-K+ leak/pump ratio contributes to the difference in endurance between fast- and slow-twitch muscles.

Science.gov (United States)

Clausen, T; Overgaard, K; Nielsen, O B

2004-02-01

Muscles containing predominantly fast-twitch (type II) fibres [ext. dig. longus (EDL)] show considerably lower contractile endurance than muscles containing mainly slow-twitch (type I) fibres (soleus). To assess whether differences in Na+-K+ fluxes and excitability might contribute to this phenomenon, we compared excitation-induced Na+-K+ leaks, Na+ channels, Na+-K+ pump capacity, force and compound action potentials (M-waves) in rat EDL and soleus muscles. Isolated muscles were mounted for isometric contractions in Krebs-Ringer bicarbonate buffer and exposed to direct or indirect continuous or intermittent electrical stimulation. The time-course of force decline and concomitant changes in Na+-K+ exchange and M-waves were recorded. During continuous stimulation at 60-120 Hz, EDL showed around fivefold faster rate of force decline than soleus. This was associated with a faster loss of excitability as estimated from the area and amplitude of the M-waves. The net uptake of Na+ and the release of K+ per action potential were respectively 6.5- and 6.6-fold larger in EDL than in soleus, which may in part be due to the larger content of Na+ channels in EDL. During intermittent stimulation with 1 s 60 Hz pulse trains, EDL showed eightfold faster rate of force decline than soleus. The considerably lower contractile endurance of fast-twitch compared with slow-twitch muscles reflects differences in the rate of excitation-induced loss of excitability. This is attributed to the much larger excitation-induced Na+ influx and K+ efflux, leading to a faster rise in [K+]o in fast-twitch muscles. This may only be partly compensated by the concomitant activation of the Na+-K+ pumps, in particular in fibres showing large passive Na+-K+ leaks or reduced content of Na+-K+ pumps. Thus, endurance depends on the leak/pump ratio for Na+ and K+.

Alterations to mitochondrial fatty-acid use in skeletal muscle after chronic exposure to hypoxia depend on metabolic phenotype.

Science.gov (United States)

Malgoyre, Alexandra; Chabert, Clovis; Tonini, Julia; Koulmann, Nathalie; Bigard, Xavier; Sanchez, Hervé

2017-03-01

We investigated the effects of chronic hypoxia on the maximal use of and sensitivity of mitochondria to different substrates in rat slow-oxidative (soleus, SOL) and fast-glycolytic (extensor digitorum longus, EDL) muscles. We studied mitochondrial respiration in situ in permeabilized myofibers, using pyruvate, octanoate, palmitoyl-carnitine (PC), or palmitoyl-coenzyme A (PCoA). The hypophagia induced by hypoxia may also alter metabolism. Therefore, we used a group of pair-fed rats (reproducing the same caloric restriction, as observed in hypoxic animals), in addition to the normoxic control fed ad libitum. The resting respiratory exchange ratio decreased after 21 days of exposure to hypobaric hypoxia (simulated elevation of 5,500 m). The respiration supported by pyruvate and octanoate were unaffected. In contrast, the maximal oxidative respiratory rate for PCoA, the transport of which depends on carnitine palmitoyltransferase 1 (CPT-1), decreased in the rapid-glycolytic EDL and increased in the slow-oxidative SOL, although hypoxia improved affinity for this substrate in both muscle types. PC and PCoA were oxidized similarly in normoxic EDL, whereas chronic hypoxia limited transport at the CPT-1 step in this muscle. The effects of hypoxia were mediated by caloric restriction in the SOL and by hypoxia itself in the EDL. We conclude that improvements in mitochondrial affinity for PCoA, a physiological long-chain fatty acid, would facilitate fatty-acid use at rest after chronic hypoxia independently of quantitative alterations of mitochondria. Conversely, decreasing the maximal oxidation of PCoA in fast-glycolytic muscles would limit fatty-acid use during exercise. NEW & NOTEWORTHY Affinity for low concentrations of long-chain fatty acids (LCFA) in mitochondria skeletal muscles increases after chronic hypoxia. Combined with a lower respiratory exchange ratio, this suggests facility for fatty acid utilization at rest. This fuel preference is related to caloric

Andreas Vesalius' 500th anniversary: the initiation of hand and forearm myology.

Science.gov (United States)

Brinkman, R J; Hage, J J

2015-11-01

Andreas Vesalius (1515-1564) was the first to market an illustrated text on the freshly dissected muscular anatomy of the human hand and forearm when he published his De Fabrica Corporis Humani Libri Septem, in 1543. To commemorate his 500th birthday, we searched the second of seven books composing De Fabrica, the annotated woodcut illustrations of De Fabrica, the Tabulae Sex, and Epitome, and an eyewitness report of a public dissection by Vesalius for references to the morphology and functions of these muscles. We found Vesalius to have recognized all currently distinguished muscles except the palmaris brevis and he noted occasional absence of some muscles. Generally, he limited the origin and insertion to bones, largely disregarding attachments to membranes and fascia. Functionally, he recorded the muscles as having a single vector and operating on only one joint. We conclude that Vesalius was nearly completely correct about the anatomy of the muscles of the forearm, but much less accurate about their function. 5. © The Author(s) 2015.

Plasticity of the transverse tubules following denervation and subsequent reinnervation in rat slow and fast muscle fibres.

Science.gov (United States)

Takekura, Hiroaki; Tamaki, Hiroyuki; Nishizawa, Tomie; Kasuga, Norikatsu

2003-01-01

We have studied the effects of short term denervation followed by reinnervation on the ultrastructure of the membrane systems and on the content of and distribution of key proteins involved in calcium regulation of fast-twitch (FT) extensor digitorum longus (EDL) and slow-twitch (ST) soleus (SOL) muscle fibres. Ischiadic nerve freezing resulted in total lack of neuromuscular transmission for 3 days followed by a slow recovery, but no decline in twitch force elicited by direct stimulation. The latter measurements indicate no significant atrophy within this time frame. The membrane systems of skeletal muscle fibres were visualized using Ca92+)-K3Fe(CN)6-OsO4 techniques and observed using a high voltage electron microscope. [3H]nitrendipine binding was used to detect levels of dihydropyridine receptor (DHPR) expression. The Ca2+ pumping free sarcoplasmic reticulum domains were not affected by the denervation, but the Ca2+ release domains were dramatically increased, particularly in the FT-EDL muscle fibres. The increase is evidenced by a doubling up of the areas of contacts between SR and transverse (t-) tubules, so that in place of the normal triadic arrangement, pentadic and heptadic junctions, formed by multiple interacting layers of ST and t-tubules are seen. Frequency of pentads and heptads increases and declines in parallel to the denervation and reinnervation but with a delay. Immunofluorecence and electron microscopy observations show presence of DHPR and ryanodine receptor clusters at pentads and heptads junctions. A significant (P muscle fibres indicating that overexpression of DHPRs accompanies the build up extra junctional contacts. The results indicate that denervation reversibly affects the domains of the membrane systems involved in excitation-contraction coupling.

Higher insulin sensitivity in EDL muscle of rats fed a low-protein, high-carbohydrate diet inhibits the caspase-3 and ubiquitin-proteasome proteolytic systems but does not increase protein synthesis.

Science.gov (United States)

Dos Santos, Maísa Pavani; Batistela, Emanuele; Pereira, Mayara Peron; Paula-Gomes, Silvia; Zanon, Neusa Maria; Kettelhut, Isis do Carmo; Karatzaferi, Christina; Andrade, Claudia Marlise Balbinotti; de França, Suélem Aparecida; Baviera, Amanda Martins; Kawashita, Nair Honda

2016-08-01

Compared with the extensor digitorum longus (EDL) muscle of control rats (C), the EDL muscle of rats fed a low-protein, high-carbohydrate diet (LPHC) showed a 36% reduction in mass. Muscle mass is determined by the balance between protein synthesis and proteolysis; thus, the aim of this work was to evaluate the components involved in these processes. Compared with the muscle from C rats, the EDL muscle from LPHC diet-fed rats showed a reduction (34%) in the in vitro basal protein synthesis and a 22% reduction in the in vitro basal proteolysis suggesting that the reduction in the mass can be associated with a change in the rate of the two processes. Soon after euthanasia, in the EDL muscles of the rats fed the LPHC diet for 15days, the activity of caspase-3 and that of components of the ubiquitin-proteasome system (atrogin-1 content and chymotrypsin-like activity) were decreased. The phosphorylation of p70(S6K) and 4E-BP1, proteins involved in protein synthesis, was also decreased. We observed an increase in the insulin-stimulated protein content of p-Akt. Thus, the higher insulin sensitivity in the EDL muscle of LPHC rats seemed to contribute to the lower proteolysis in LPHC rats. However, even with the higher insulin sensitivity, the reduction in p-E4-BP1 and p70(S6K) indicates a reduction in protein synthesis, showing that factors other than insulin can have a greater effect on the control of protein synthesis. Copyright © 2016 Elsevier Inc. All rights reserved.

Chiasma crurale: intersection of the tibialis posterior and flexor digitorum longus tendons above the ankle. Magnetic resonance imaging-anatomic correlation in cadavers

Energy Technology Data Exchange (ETDEWEB)

Buck, Florian M. [VA San Diego Medical Center, Department of Radiology, San Diego, CA (United States); Institut fuer Diagnostische Radiologie, Zurich (Switzerland); Gheno, Ramon; Nico, Marcelo A.C.; Trudell, Debra J.; Resnick, Donald [VA San Diego Medical Center, Department of Radiology, San Diego, CA (United States); Haghighi, Parviz [VA San Diego Medical Center, Department of Pathology, San Diego, CA (United States)

2010-06-15

To determine the precise anatomy and magnetic resonance (MR) imaging appearance of the chiasma crurale in cadavers, paying special attention to degenerative changes Twelve fresh human ankles were harvested from 11 nonembalmed cadavers (mean age at death 77 years) and used according to institutional guidelines. MR imaging and MR tenography were used to investigate the anatomy of the chiasma crurale using proton density-weighted sequences. The gross anatomy of the chiasma crurale was evaluated and compared to the MR imaging findings. Histology was used to elucidate further the structure of the chiasma crurale. Above the chiasma, five specimens had a small amount of fat tissue between the tibialis posterior and flexor digitorum longus tendon. In all specimens both tendons had a sheath below the chiasma but not above it. At the central portion of the chiasma there was no soft tissue between the tendons, except in two specimens that showed an anatomic variant consisting of a thick septum connecting the tibial periosteum and the deep transverse fascia of the leg. In MR images, eight specimens showed what were believed to be degenerative changes in the tendons at the level of the chiasma. However, during gross inspection and histologic analysis of the specimens, there was no tendon degeneration visible. At the central portion of the chiasma, there is no tissue between the tibialis posterior and flexor digitorum longus tendons unless there is an anatomic variant. At the chiasma crurale, areas with irregular tendon surfaces are normal findings and are not associated with tendon degeneration (fraying). (orig.)

Complex Anatomic Abnormalities of the Lower Leg Muscles and Tendons Associated With Phocomelia: A Case Report.

Science.gov (United States)

Hodo, Thomas; Hamrick, Mark; Melenevsky, Yulia

Musculoskeletal anatomy is widely known to have components that stray from the norm in the form of variant muscle and tendon presence, absence, origin, insertion, and bifurcation. Although these variant muscles and tendons might be deemed incidental and insignificant findings by most, they can be important contributors to pathologic physiology or, more importantly, an option for effective treatment. In the present case report, we describe a patient with phocomelia and Müllerian abnormalities secondary to in utero thalidomide exposure. The patient had experienced recurrent bilateral foot pain accompanied by numbness, stiffness, swelling, and longstanding pes planus. These symptoms persisted despite conservative treatment with orthotics, steroids, and nonsteroidal anti-inflammatory drugs. Radiographic imaging showed dysmorphic and degenerative changes of the ankle and foot joints. Further investigation with magnetic resonance imaging revealed complex anatomic abnormalities, including the absence of the posterior tibialis and peroneus brevis, lateralization of the peroneus longus, and the presence of a variant anterior compartment muscle. The variant structure was likely a previously described anterior compartment variant, anterior fibulocalcaneus, and might have been a source of the recurrent pain. Also, the absence of the posterior tibialis might have caused the pes planus in the present patient, considering that posterior tibialis tendon dysfunction is the most common cause of acquired pes planus. Although thalidomide infrequently affects the lower extremities, its effects on growth and development were likely the cause of this rare array of anatomic abnormalities and resulting ankle and foot pathologic features. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

The action of ryanodine on rat fast and slow intact skeletal muscles.

Science.gov (United States)

Fryer, M W; Lamb, G D; Neering, I R

1989-07-01

1. The action of ryanodine on force development of bundles dissected from rat extensor digitorum longus (EDL) and soleus muscles has been examined. 2. Ryanodine (100-5000 nM) irreversibly depressed twitch and tetanic tension of both muscle types in a dose-related manner. 3. At concentrations above 250 nM, ryanodine induced a slowly developing, dose-dependent contracture which could not be blocked by 5 mM-Co2+. Increasing the stimulation rate or decreasing the oxygenation of the preparation accelerated the rate of contracture development while the total removal of extracellular Ca2+ was required to prevent it. 4. Following the relaxation of the initial contracture (IC) in Ca2+-free solution, a second type of contracture (SC) could be induced by the readdition of Ca2+. This contracture differed from IC in that it was dependent on Ca2+ in the millimolar range and was prevented by 5 mM-Co2+. Both IC and SC were relaxed by perfusion with Ca2+-free, EGTA-containing solution. 5. Subcontracture doses of ryanodine (100 nM) markedly potentiated caffeine contractures of both muscle types. 6. Asymmetric charge movement in EDL fibres was recorded with the Vaseline-gap technique. The amount of charge moved near threshold was virtually unaffected by the presence of 10 microM-ryanodine over the time examined. 7. The results are consistent with the suggestion that ryanodine locks the calcium release channels of the sarcoplasmic reticulum (SR) in an open subconductance state with reduced conductance. It appears that lowering the external calcium concentration might still inactivate the release channels after they have been blocked open by ryanodine, possibly by an effect on the T-tubular voltage sensor.

Reliability of ultrasound for measurement of selected foot structures.

Science.gov (United States)

Crofts, G; Angin, S; Mickle, K J; Hill, S; Nester, C J

2014-01-01

Understanding the relationship between the lower leg muscles, foot structures and function is essential to explain how disease or injury may relate to changes in foot function and clinical pathology. The aim of this study was to investigate the inter-operator reliability of an ultrasound protocol to quantify features of: rear, mid and forefoot sections of the plantar fascia (PF); flexor hallucis brevis (FHB); flexor digitorum brevis (FDB); abductor hallucis (AbH); flexor digitorum longus (FDL); flexor hallucis longus (FHL); tibialis anterior (TA); and peroneus longus and brevis (PER). A sample of 6 females and 4 males (mean age 29.1 ± 7.2 years, mean BMI 25.5 ± 4.8) was recruited from a university student and staff population. Scans were obtained using a portable Venue 40 musculoskeletal ultrasound system (GE Healthcare UK) with a 5-13 MHz wideband linear array probe with a 12.7 mm × 47.1mm footprint by two operators in the same scanning session. Intraclass Correlation Coefficients (ICC) values for muscle thickness (ICC range 0.90-0.97), plantar fascia thickness (ICC range 0.94-0.98) and cross sectional muscle measurements (ICC range 0.91-0.98) revealed excellent inter-operator reliability. The limits of agreement, relative to structure size, ranged from 9.0% to 17.5% for muscle thickness, 11.0-18.0% for plantar fascia, and 11.0-26.0% for cross sectional area measurements. The ultrasound protocol implemented in this work has been shown to be reliable. It therefore offers the opportunity to quantify the structures concerned and better understand their contributions to foot function. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

A small-molecule benzimidazole derivative that potently activates AMPK to increase glucose transport in skeletal muscle: comparison with effects of contraction and other AMPK activators.

Science.gov (United States)

Lai, Yu-Chiang; Kviklyte, Samanta; Vertommen, Didier; Lantier, Louise; Foretz, Marc; Viollet, Benoît; Hallén, Stefan; Rider, Mark H

2014-06-15

AMPK (AMP-activated protein kinase) is an attractive therapeutic drug target for treating metabolic disorders. We studied the effects of an AMPK activator developed by Merck (ex229 from patent application WO2010036613), comparing chemical activation with contraction in intact incubated skeletal muscles. We also compared effects of ex229 with those of the Abbott A769662 compound and AICAR (5-amino-4-imidazolecarboxamide riboside). In rat epitrochlearis muscle, ex229 dose-dependently increased AMPK activity of α1-, α2-, β1- and β2-containing complexes with significant increases in AMPK activity seen at a concentration of 50 μM. At a concentration of 100 μM, AMPK activation was similar to that observed after contraction and importantly led to an ~2-fold increase in glucose uptake. In AMPK α1-/α2-catalytic subunit double-knockout myotubes incubated with ex229, the increases in glucose uptake and ACC (acetyl-CoA carboxylase) phosphorylation seen in control cells were completely abolished, suggesting that the effects of the compound were AMPK-dependent. When muscle glycogen levels were reduced by ~50% after starvation, ex229-induced AMPK activation and glucose uptake were amplified in a wortmannin-independent manner. In L6 myotubes incubated with ex229, fatty acid oxidation was increased. Furthermore, in mouse EDL (extensor digitorum longus) and soleus muscles, ex229 increased both AMPK activity and glucose uptake at least 2-fold. In summary, ex229 efficiently activated skeletal muscle AMPK and elicited metabolic effects in muscle appropriate for treating Type 2 diabetes by stimulating glucose uptake and increasing fatty acid oxidation.

DYNAMIC HIP ADDUCTION, ABDUCTION AND ABDOMINAL EXERCISES FROM THE HOLMICH GROIN-INJURY PREVENTION PROGRAM ARE INTENSE ENOUGH TO BE CONSIDERED STRENGTHENING EXERCISES - A CROSS-SECTIONAL STUDY

DEFF Research Database (Denmark)

Krommes, Kasper; Bandholm, Thomas; Jakobsen, Markus D

2017-01-01

and external obliques during isometric adduction against a football placed between the ankles (IBA), isometric adduction against a football placed between the knees (IBK), folding knife (FK), cross-country skiing on one leg (CCS), adduction partner (ADP) and abduction partner (ABP). The EMG-signals were...... normalized (nEMG) to an isometric maximal voluntary contraction for each tested muscle. RESULTS: Adductor longus activity during IBA was 84% nEMG (95% CI: 70-98) and during IBK it was 118% nEMG (95% CI 106-130). For the dynamic exercises, ADP evoked 87% nEMG (95% CI 69-105) in adductor longus, ABP evoked 88...

Evaluation of muscle fatigue of wheelchair basketball players with spinal cord injury using recurrence quantification analysis of surface EMG.

Science.gov (United States)

Uzun, S; Pourmoghaddam, A; Hieronymus, M; Thrasher, T A

2012-11-01

Wheelchair basketball is the most popular exercise activity among individuals with spinal cord injury (SCI). The purpose of this study was to investigate muscular endurance and fatigue in wheelchair basketball athletes with SCI using surface electromyography (SEMG) and maximal torque values. SEMG characteristics of 10 wheelchair basketball players (WBP) were compared to 13 able-bodied basketball players and 12 sedentary able-bodied subjects. Participants performed sustained isometric elbow flexion at 50% maximal voluntary contraction until exhaustion. Elbow flexion torque and SEMG signals were recorded from three elbow flexor muscles: biceps brachii longus, biceps brachii brevis and brachioradialis. SEMG signals were clustered into 0.5-s epochs with 50% overlap. Root mean square (RMS) and median frequency (MDF) of SEMG signals were calculated for each muscle and epoch as traditional fatigue monitoring. Recurrence quantification analysis was used to extract the percentage of determinism (%DET) of SEMG signals. The slope of the %DET for basketball players and WBP showed slower increase with time than the sedentary able-bodied control group for three different elbow flexor muscles, while no difference was observed for the slope of the %DET between basketball and WBP. This result indicated that the athletes are less fatigable during the task effort than the nonathletes. Normalized MDF slope decay exhibited similar results between the groups as %DET, while the slope of the normalized RMS failed to show any significant differences among the groups (p > 0.05). MDF and %DET could be useful for the evaluation of muscle fatigue in wheelchair basketball training. No conclusions about special training for WBP could be determined.

Differential expression of FGF receptors and of myogenic regulatory factors in primary cultures of satellite cells originating from fast (EDL) and slow (Soleus) twitch rat muscles.

Science.gov (United States)

Martelly, I; Soulet, L; Bonnavaud, S; Cebrian, J; Gautron, J; Barritault, D

2000-11-01

In the rat, the fast and slow twitch muscles respectively Extensor digitorum longus (EDL) and Soleus present differential characteristics during regeneration. This suggests that their satellite cells responsible for muscle growth and repair represent distinct cellular populations. We have previously shown that satellite cells dissociated from Soleus and grown in vitro proliferate more readily than those isolated from EDL muscle. Fibroblast growth factors (FGFs) are known as regulators of myoblast proliferation and several studies have revealed a relationship between the response of myoblasts to FGF and the expression of myogenic regulatory factors (MRF) of the MyoD family by myoblasts. Therefore, we presently examined the possibility that the satellite cells isolated from EDL and Soleus muscles differ in the expression of FGF receptors (FGF-R) and of MRF expression. FGF-R1 and -R4 were strongly expressed in proliferating cultures whereas FGF-R2 and R3 were not detected in these cultures. In differentiating cultures, only -R1 was present in EDL satellite cells while FGF-R4 was also still expressed in Soleus cells. Interestingly, the unconventional receptor for FGF called cystein rich FGF receptor (CFR), of yet unknown function, was mainly detected in EDL satellite cell cultures. Soleus and EDL satellite cell cultures also differed in the expression MRFs. These results are consistent with the notion that satellite cells from fast and slow twitch muscles belong to different types of myogenic cells and suggest that satellite cells might play distinct roles in the formation and diversification of fast and slow fibres.

Increased hypoxia-inducible factor-1α in striated muscle of tumor-bearing mice.

Science.gov (United States)

Devine, Raymond D; Bicer, Sabahattin; Reiser, Peter J; Wold, Loren E

2017-06-01

Cancer cachexia is a progressive wasting disease resulting in significant effects on the quality of life and high mortality. Most studies on cancer cachexia have focused on skeletal muscle; however, the heart is now recognized as a major site of cachexia-related effects. To elucidate possible mechanisms, a proteomic study was performed on the left ventricles of colon-26 (C26) adenocarcinoma tumor-bearing mice. The results revealed several changes in proteins involved in metabolism. An integrated pathway analysis of the results revealed a common mediator in hypoxia-inducible factor-1α (HIF-1α). Work by other laboratories has shown that extensive metabolic restructuring in the C26 mouse model causes changes in gene expression that may be affected directly by HIF-1α, such as glucose metabolic genes. M-mode echocardiography showed progressive decline in heart function by day 19 , exhibited by significantly decreased ejection fraction and fractional shortening, along with posterior wall thickness. Using Western blot analysis, we confirmed that HIF-1α is significantly upregulated in the heart, whereas there were no changes in its regulatory proteins, prolyl hydroxylase domain-containing protein 2 (PHD2) and von Hippel-Lindau protein (VHL). PHD2 requires both oxygen and iron as cofactors for the hydroxylation of HIF-1α, marking it for ubiquination via VHL and subsequent destruction by the proteasome complex. We examined venous blood gas values in the tumor-bearing mice and found significantly lower oxygen concentration compared with control animals in the third week after tumor inoculation. We also examined select skeletal muscles to determine whether they are similarly affected. In the diaphragm, extensor digitorum longus, and soleus, we found significantly increased HIF-1α in tumor-bearing mice, indicating a hypoxic response, not only in the heart, but also in skeletal muscle. These results indicate that HIF-1α may contribute, in part, to the metabolic changes

The effects of elevated levels of sodium bicarbonate (NaHCO₃) on the acute power output and time to fatigue of maximally stimulated mouse soleus and EDL muscles.

Science.gov (United States)

Higgins, M F; Tallis, J; Price, M J; James, R S

2013-05-01

This study examined the effects of elevated buffer capacity [~32 mM HCO₃(-)] through administration of sodium bicarbonate (NaHCO₃) on maximally stimulated isolated mouse soleus (SOL) and extensor digitorum longus (EDL) muscles undergoing cyclical length changes at 37 °C. The elevated buffering capacity was of an equivalent level to that achieved in humans with acute oral supplementation. We evaluated the acute effects of elevated [HCO₃(-)] on (1) maximal acute power output (PO) and (2) time to fatigue to 60 % of maximum control PO (TLIM60), the level of decline in muscle PO observed in humans undertaking similar exercise, using the work loop technique. Acute PO was on average 7.0 ± 4.8 % greater for NaHCO₃-treated EDL muscles (P < 0.001; ES = 2.0) and 3.6 ± 1.8 % greater for NaHCO₃-treated SOL muscles (P < 0.001; ES = 2.3) compared to CON. Increases in PO were likely due to greater force production throughout shortening. The acute effects of NaHCO₃ on EDL were significantly greater (P < 0.001; ES = 0.9) than on SOL. Treatment of EDL (P = 0.22; ES = 0.6) and SOL (P = 0.19; ES = 0.9) with NaHCO₃ did not alter the pattern of fatigue. Although significant differences were not observed in whole group data, the fatigability of muscle performance was variable, suggesting that there might be inter-individual differences in response to NaHCO₃ supplementation. These results present the best indication to date that NaHCO₃ has direct peripheral effects on mammalian skeletal muscle resulting in increased acute power output.

Dihydrotestosterone treatment rescues the decline in protein synthesis as a result of sarcopenia in isolated mouse skeletal muscle fibres.

Science.gov (United States)

Wendowski, Oskar; Redshaw, Zoe; Mutungi, Gabriel

2017-02-01

Sarcopenia, the progressive decline in skeletal muscle mass and function with age, is a debilitating condition. It leads to inactivity, falls, and loss of independence. Despite this, its cause(s) and the underlying mechanism(s) are still poorly understood. In this study, small skeletal muscle fibre bundles isolated from the extensor digitorum longus (a fast-twitch muscle) and the soleus (a slow-twitch muscle) of adult mice of different ages (range 100-900 days old) were used to investigate the effects of ageing and dihydrotestosterone (DHT) treatment on protein synthesis as well as the expression and function of two amino acid transporters; the sodium-coupled neutral amino acid transporter (SNAT) 2, and the sodium-independent L-type amino-acid transporter (LAT) 2. At all ages investigated, protein synthesis was always higher in the slow-twitch than in the fast-twitch muscle fibres and decreased with age in both fibre types. However, the decline was greater in the fast-twitch than in the slow-twitch fibres and was accompanied by a reduction in the expression of SNAT2 and LAT2 at the protein level. Again, the decrease in the expression of the amino acid transporters was greater in the fast-twitch than in the slow-twitch fibres. In contrast, ageing had no effect on SNAT2 and LAT2 expressions at the mRNA level. Treating the muscle fibre bundles with physiological concentrations (~2 nM) of DHT for 1 h completely reversed the effects of ageing on protein synthesis and the expression of SNAT2 and LAT2 protein in both fibre types. From the observations that ageing is accompanied by a reduction in protein synthesis and transporter expression and that these effects are reversed by DHT treatment, we conclude that sarcopenia arises from an age-dependent reduction in protein synthesis caused, in part, by the lack of or by the low bioavailability of the male sex steroid, DHT.

Slow-tonic muscle fibers and their potential innervation in the turtle, Pseudemys (Trachemys) scripta elegans.

Science.gov (United States)

Callister, Robert J; Pierce, Patricia A; McDonagh, Jennifer C; Stuart, Douglas G

2005-04-01

A description is provided of the ratio of slow-tonic vs. slow- and fast-twitch fibers for five muscles in the adult turtle, Pseudemys (Trachemys) scripta elegans. The cross-sectional area of each fiber type and an estimation of the relative (weighted) cross-sectional area occupied by the different fiber types are also provided. Two hindlimb muscles (flexor digitorum longus, FDL; external gastrocnemius, EG) were selected on the basis of their suitability for future motor-unit studies. Three neck muscles (the fourth head of testo-cervicis, TeC4; the fourth head of retrahens capitus collique, RCCQ4; transversalis cervicis, TrC) were chosen for their progressively decreasing oxidative capacity. Serial sections were stained for myosin adenosine triphosphatase (ATPase), NADH-diaphorase, and alpha-glycerophosphate dehydrogenase (alpha-GPDH). Conventional fiber-type classification was then performed using indirect markers for contraction speed and oxidative (aerobic) vs. glycolytic (anaerobic) metabolism: i.e., slow oxidative (SO, including slow-twitch and possibly slow-tonic fibers), fast-twitch, oxidative-glycolytic (FOG), and fast-twitch glycolytic (Fg) fibers. Slow-tonic fibers in the SO class were then revealed by directing the monoclonal antibody, ALD-58 (raised against the slow-tonic fiber myosin heavy chain of chicken anterior latissimus dorsi), to additional muscle cross sections. All five of the tested muscles contained the four fiber types, with the ATPase-stained fibers including both slow-tonic and slow-twitch fibers. The extreme distributions of SO fibers were in the predominately glycolytic TrC vs. the predominately oxidative TeC4 muscle (TrC-SO, 9%; FOG, 20%; Fg, 71% vs. TeC4-SO, 58%: FOG, 16%; Fg, 25%). Across the five muscles, the relative prevalence of slow-tonic fibers (4-47%) paralleled that of the SO fibers (9-58%). TeC4 had the highest prevalence of slow-tonic fibers (47%). The test muscles exhibited varying degrees of regional concentration of each

Tetanic contraction induces enhancement of fatigability and sarcomeric damage in atrophic skeletal muscle and its underlying molecular mechanisms.

Science.gov (United States)

Yu, Zhi-Bin

2013-11-01

Muscle unloading due to long-term exposure of weightlessness or simulated weightlessness causes atrophy, loss of functional capacity, impaired locomotor coordination, and decreased resistance to fatigue in the antigravity muscles of the lower limbs. Besides reducing astronauts' mobility in space and on returning to a gravity environment, the molecular mechanisms for the adaptation of skeletal muscle to unloading also play an important medical role in conditions such as disuse and paralysis. The tail-suspended rat model was used to simulate the effects of weightlessness on skeletal muscles and to induce muscle unloading in the rat hindlimb. Our series studies have shown that the maximum of twitch tension and the twitch duration decreased significantly in the atrophic soleus muscles, the maximal tension of high-frequency tetanic contraction was significantly reduced in 2-week unloaded soleus muscles, however, the fatigability of high-frequency tetanic contraction increased after one week of unloading. The maximal isometric tension of intermittent tetanic contraction at optimal stimulating frequency did not alter in 1- and 2-week unloaded soleus, but significantly decreased in 4-week unloaded soleus. The 1-week unloaded soleus, but not extensor digitorum longus (EDL), was more susceptible to fatigue during intermittent tetanic contraction than the synchronous controls. The changes in K+ channel characteristics may increase the fatigability during high-frequency tetanic contraction in atrophic soleus muscles. High fatigability of intermittent tetanic contraction may be involved in enhanced activity of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) and switching from slow to fast isoform of myosin heavy chain, tropomyosin, troponin I and T subunit in atrophic soleus muscles. Unloaded soleus muscle also showed a decreased protein level of neuronal nitric oxide synthase (nNOS), and the reduction in nNOS-derived NO increased frequency of calcium sparks and elevated

Ankle and toe muscle strength characteristics in runners with a history of medial tibial stress syndrome.

Science.gov (United States)

Saeki, Junya; Nakamura, Masatoshi; Nakao, Sayaka; Fujita, Kosuke; Yanase, Ko; Morishita, Katsuyuki; Ichihashi, Noriaki

2017-01-01

A high proportion of flexor digitorum longus attachment is found at the posteromedial border of the tibia, which is the most common location of medial tibial stress syndrome (MTSS). Therefore, plantar flexion strength of the lesser toes could be related to MTSS; however, the relationship between MTSS and muscle strength of the hallux and lesser toes is not yet evaluated due to the lack of quantitative methods. This study investigated the muscle strength characteristics in runners with a history of MTSS by using a newly developed device to measure the muscle strength of the hallux, lesser toes, and ankle. This study comprised 27 collegiate male runner participants (20.0 ± 1.6 years, 172.1 ± 5.1 cm, 57.5 ± 4.0 kg). Maximal voluntary isometric contraction (MVIC) torque of the plantar flexion, dorsiflexion, inversion, and eversion of the ankle were measured by using an electric dynamometer. MVIC torque of the 1st metatarsophalangeal joint (MTPJ) and 2nd-5th MTPJ were measured by using a custom-made torque-measuring device. MVIC torques were compared between runners with and without a history of MTSS. MVIC torque of the 1st MTPJ plantar flexion was significantly higher in runners with a history of MTSS than in those without it. In contrast, there were no significant differences in the MVIC torque values of the 2nd-5th MTPJ plantar flexion and each MVIC torque of the ankle between runners with and without a history of MTSS. A history of MTSS increased the isometric FHL strength.

Role of calpain in eccentric contraction-induced proteolysis of Ca2+-regulatory proteins and force depression in rat fast-twitch skeletal muscle.

Science.gov (United States)

Kanzaki, Keita; Watanabe, Daiki; Kuratani, Mai; Yamada, Takashi; Matsunaga, Satoshi; Wada, Masanobu

2017-02-01

The aim of this study was to examine the in vivo effects of eccentric contraction (ECC) on calpain-dependent proteolysis of Ca 2+ -regulatory proteins and force production in fast-twitch skeletal muscles. Rat extensor digitorum longus muscles were exposed to 200 repeated ECC in situ and excised immediately [recovery 0 (REC0)] or 3 days [recovery 3 (REC3)] after cessation of ECC. Calpain inhibitor (CI)-treated rats were intraperitoneally injected with MDL-28170 before ECC and during REC3. Tetanic force was markedly reduced at REC0 and remained reduced at REC3. CI treatment ameliorated the ECC-induced force decline but only at REC3. No evidence was found for proteolysis of dihydropyridine receptor (DHPR), junctophilin (JP)1, JP2, ryanodine receptor (RyR), sarcoplasmic reticulum Ca 2+ -ATPase (SERCA)1a, or junctional face protein-45 at REC0. At REC3, ECC resulted in decreases in DHPR, JP1, JP2, RyR, and SERCA1a. CI treatment prevented the decreases in DHPR, JP1, and JP2, whereas it had little effect on RyR and SERCA1a. These findings suggest that DHPR, JP1, and JP2, but not RyR and SERCA1a, undergo calpain-dependent proteolysis in in vivo muscles subjected to ECC and that impaired function of DHPR and/or JP might cause prolonged force deficits with ECC. NEW & NOTEWORTHY Calpain-dependent proteolysis is one of the contributing factors to muscle damage that occurs with eccentric contraction (ECC). It is unclear, however, whether calpains account for proteolysis of Ca 2+ -regulatory proteins in in vivo muscles subjected to ECC. Here, we provide evidence that dihydropyridine receptor and junctophilin, but not ryanodine receptor and sarcoplasmic reticulum Ca 2+ -ATPase, undergo calpain-dependent proteolysis. Copyright © 2017 the American Physiological Society.

EMG evaluation of hip adduction exercises for soccer players

DEFF Research Database (Denmark)

Serner, Andreas; Jakobsen, Markus Due; Andersen, Lars Louis

2014-01-01

INTRODUCTION: Exercise programmes are used in the prevention and treatment of adductor-related groin injuries in soccer; however, there is a lack of knowledge concerning the intensity of frequently used exercises. OBJECTIVE: Primarily to investigate muscle activity of adductor longus during six...... traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals. MATERIALS AND METHODS: 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally...

Fine-structural distribution of MMP-2 and MMP-9 activities in the rat skeletal muscle upon training: a study by high-resolution in situ zymography.

Science.gov (United States)

Yeghiazaryan, Marine; Żybura-Broda, Katarzyna; Cabaj, Anna; Włodarczyk, Jakub; Sławińska, Urszula; Rylski, Marcin; Wilczyński, Grzegorz M

2012-07-01

Matrix metalloproteinases (MMPs) are key regulators of extracellular matrix remodeling, but have also important intracellular targets. The purpose of this study was to examine the activity and subcellular localization of the gelatinases MMP-2 and MMP-9 in skeletal muscle of control and physically trained rats. In control hind limb muscle, the activity of the gelatinases was barely detectable. In contrast, after 5 days of intense exercise, in Soleus (Sol), but not Extensor digitorum longus (EDL) muscle, significant upregulation of gelatinolytic activity in myofibers was observed mainly in the nuclei, as assessed by high resolution in situ zymography. The nuclei of quiescent satellite cells did not contain the activity. Within the myonuclei, the gelatinolytic activity colocalized with an activated RNA Polymerase II. Also in Sol, but not in EDL, there were few foci of mononuclear cells with strongly positive cytoplasm, associated with apparent necrotic myofibers. These cells were identified as activated satellite cells/myoblasts. No extracellular gelatinase activity was observed. Gel zymography combined with subcellular fractionation revealed training-related upregulation of active MMP-2 in the nuclear fraction, and increase of active MMP-9 in the cytoplasmic fraction of Sol. Using RT-PCR, selective increase in MMP-9 mRNA was observed. We conclude that training activates nuclear MMP-2, and increases expression and activity of cytoplasmic MMP-9 in Sol, but not in EDL. Our results suggest that the gelatinases are involved in muscle adaptation to training, and that MMP-2 may play a novel role in myonuclear functions.

Effects of 2 ankle destabilization devices on electromyography measures during functional exercises in individuals with chronic ankle instability.

Science.gov (United States)

Donovan, Luke; Hart, Joseph M; Hertel, Jay

2015-03-01

Randomized crossover laboratory study. To determine the effects of ankle destabilization devices on surface electromyography (sEMG) measures of selected lower extremity muscles during functional exercises in participants with chronic ankle instability. Ankle destabilization devices are rehabilitation tools that can be worn as a boot or sandal to increase lower extremity muscle activation during walking in healthy individuals. However, they have not been tested in a population with pathology. Fifteen adults with chronic ankle instability participated. Surface electromyography electrodes were located over the anterior tibialis, fibularis longus, lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius. The activity level of these muscles was recorded in a single testing session during unipedal stance with eyes closed, the Star Excursion Balance Test, lateral hops, and treadmill walking. Each task was performed under 3 conditions: shod, ankle destabilization boot, and ankle destabilization sandal. Surface electromyography signal amplitudes were measured for each muscle during each exercise for all 3 conditions. Participants demonstrated a significant increase, with moderate to large effect sizes, in sEMG signal amplitude of the fibularis longus in the ankle destabilization boot and ankle destabilization sandal conditions during the unipedal eyes-closed balance test, the Star Excursion Balance Test in the anterior and posteromedial directions, lateral hops, and walking, when compared to the shod condition. Both devices also resulted in an increase in sEMG signal amplitudes, with large effect sizes of the lateral gastrocnemius, rectus femoris, biceps femoris, and gluteus medius during the unipedal-stance-with-eyes-closed test, compared to the shod condition. Wearing ankle destabilization devices caused greater muscle activation during functional exercises in individuals with chronic ankle instability. Based on the magnitude of the effect, there were

Preconditioning of skeletal muscle against contraction-induced damage: the role of adaptations to oxidants in mice.

Science.gov (United States)

McArdle, F; Spiers, S; Aldemir, H; Vasilaki, A; Beaver, A; Iwanejko, L; McArdle, A; Jackson, M J

2004-11-15

Adaptations of skeletal muscle following exercise are accompanied by changes in gene expression, which can result in protection against subsequent potentially damaging exercise. One cellular signal activating these adaptations may be an increased production of reactive oxygen and nitrogen species (ROS). The aim of this study was to examine the effect of a short period of non-damaging contractions on the subsequent susceptibility of muscle to contraction-induced damage and to examine the changes in gene expression that occur following the initial contraction protocol. Comparisons with changes in gene expression in cultured myotubes following treatment with a non-damaging concentration of hydrogen peroxide (H(2)O(2)) were used to identify redox-sensitive genes whose expression may be modified by the increased ROS production during contractions. Hindlimb muscles of mice were subjected to a preconditioning, non-damaging isometric contraction protocol in vivo. After 4 or 12 h, extensor digitorum longus (EDL) and soleus muscles were removed and subjected to a (normally) damaging contraction protocol in vitro. Muscles were also analysed for changes in gene expression induced by the preconditioning protocol using cDNA expression techniques. In a parallel study, C(2)C(12) myotubes were treated with a non-damaging concentration (100 microM) of H(2)O(2) and, at 4 and 12 h following treatment, myotubes were treated with a damaging concentration of H(2)O(2) (2 mM). Myotubes were analysed for changes in gene expression at 4 h following treatment with 100 microM H(2)O(2) alone. Data demonstrate that a prior period of non-damaging contractile activity resulted in significant protection of EDL and soleus muscles against a normally damaging contraction protocol 4 h later. This protection was associated with significant changes in gene expression. Prior treatment of myotubes with a non-damaging concentration of H(2)O(2) also resulted in significant protection against a damaging

Hydrogen peroxide increases depolarization-induced contraction of mechanically skinned slow twitch fibres from rat skeletal muscles.

Science.gov (United States)

Plant, David R; Lynch, Gordon S; Williams, David A

2002-03-15

The effect of exogenous hydrogen peroxide (H(2)O(2)) on excitation-contraction (E-C) coupling and sarcoplasmic reticulum (SR) function was compared in mechanically skinned slow twitch fibres (prepared from the soleus muscles) and fast twitch fibres (prepared from the extensor digitorum longus; EDL muscles) of adult rats. Equilibration (5 min) with 1 mM H(2)O(2) diminished the ability of the Ca(2+)-depleted SR to reload Ca(2+) in both slow (P fast twitch fibres (P fast twitch fibres by 24 +/- 5 % (P slow twitch fibres. Treatment with 1 mM H(2)O(2) also increased the peak force of low [caffeine] contracture by approximately 45% in both fibre types compared to control (P slow twitch fibres, compared to control (no H(2)O(2); P fast twitch fibres was not altered by 1 mM H(2)O(2) treatment. Equilibration with 5 mM H(2)O(2) induced a spontaneous force response in both slow and fast twitch fibres, which could be partly reversed by 2 min treatment with 10 mM DTT. Peak DICR was also increased approximately 40% by 5 mM H(2)O(2) in slow twitch fibres compared to control (no H(2)O(2); P slow but not fast twitch fibres. The increase in depolarization-induced contraction in slow twitch fibres might be mediated by an increased SR Ca(2+) release during contraction and/or an increase in Ca(2+) sensitivity.

Bone and muscular anatomy of the forearm and hand in Tapirus terrestris (Perissodactyla, Tapiridae

Directory of Open Access Journals (Sweden)

Saulo Gonçalves Pereira

2017-05-01

Full Text Available In Brazil, there are two species of tapirs, the largest land mammals in Brazil, which belong to the order Perissodactyla, as do horses. Our aim was to describe the bone and muscular anatomy of the forearm and hand in T. terrestris and to propose adaptive functions. We used five anatomical specimens donated from a breeder to the Laboratory for Teaching and Research on Wild Animals of the Federal University of Uberlandia after death with no trauma. The bones were analyzed, the muscles dissected, and both described. The bones of the forearm and hand of the tapir are the ulna, radius, Os. metacarpalia, Os. carpi, phalanx and Os. sesamoideum. The muscles are M. extensor carpi radialis, M. ulnaris lateralis; M. flexor carpi radialis; M. extensor radialis communis; M. extensor digitorum longus II, III, IV and V, M. extensor digitorum lateralis; M. extensor digitorum; M. abductor longus; M. flexor digiti superficialis; M. flexor digitalis; M. flexor carpi ulnaris; M. flexor carpi obliquus; and M. interossei and M. lumbricales. Characteristics of bone and muscle structure are adapted to the development of the animal’s niche.

GLPG0492, a novel selective androgen receptor modulator, improves muscle performance in the exercised-mdx mouse model of muscular dystrophy.

Science.gov (United States)

Cozzoli, Anna; Capogrosso, Roberta Francesca; Sblendorio, Valeriana Teresa; Dinardo, Maria Maddalena; Jagerschmidt, Catherine; Namour, Florence; Camerino, Giulia Maria; De Luca, Annamaria

2013-06-01

Anabolic drugs may counteract muscle wasting and dysfunction in Duchenne muscular dystrophy (DMD); however, steroids have unwanted side effects. We focused on GLPG0492, a new non-steroidal selective androgen receptor modulator that is currently under development for musculo-skeletal diseases such as sarcopenia and cachexia. GLPG0492 was tested in the exercised mdx mouse model of DMD in a 4-week trial at a single high dose (30 mg/kg, 6 day/week s.c.), and the results were compared with those from the administration of α-methylprednisolone (PDN; 1 mg/kg, i.p.) and nandrolone (NAND, 5 mg/kg, s.c.). This assessment was followed by a 12-week dose-dependence study (0.3-30 mg/kg s.c.). The outcomes were evaluated in vivo and ex vivo on functional, histological and biochemical parameters. Similar to PDN and NAND, GLPG0492 significantly increased mouse strength. In acute exhaustion tests, a surrogate of the 6-min walking test used in DMD patients, GLPG0492 preserved running performance, whereas vehicle- or comparator-treated animals showed a significant increase in fatigue (30-50%). Ex vivo, all drugs resulted in a modest but significant increase of diaphragm force. In parallel, a decrease in the non-muscle area and markers of fibrosis was observed in GLPG0492- and NAND-treated mice. The drugs exerted minor effects on limb muscles; however, electrophysiological biomarkers were ameliorated in extensor digitorum longus muscle. The longer dose-dependence study confirmed the effect on mdx mouse strength and resistance to fatigue and demonstrated the efficacy of lower drug doses on in vivo and ex vivo functional parameters. These results support the interest of further studies of GLPG0492 as a potential treatment for DMD. Copyright © 2013 Elsevier Ltd. All rights reserved.

Laparoscopic hernia repair with adductor tenotomy for athletic pubalgia: an established procedure for an obscure entity.

Science.gov (United States)

Rossidis, Georgios; Perry, Andrew; Abbas, Husain; Motamarry, Isaac; Lux, Tamara; Farmer, Kevin; Moser, Michael; Clugston, Jay; Caban, Angel; Ben-David, Kfir

2015-02-01

Athletic pubalgia is a syndrome of chronic lower abdomen and groin pain that occurs in athletes. It is the direct result of stress and microtears of the rectus abdominis inserting on the pubis from the antagonizing adductor longus muscles, and weakness of the posterior transversalis fascia and bulging of the inguinal floor. Under IRB approval, we conducted a retrospective review of our prospectively competitive athlete patients with athletic pubalgia from 2007 to 2013. A cohort of 54 patients was examined. Mean age was 22.4 years. Most patients were football players (n = 23), triathlon (n = 11), track and field (n = 6), soccer players (n = 5), baseball players (n = 4), swimmers (n = 3), golfer (n = 1), and tennis player (n = 1). Fifty one were males and three were females. All patients failed medical therapy with physiotherapy prior to surgery. 76 % of patients had an MRI performed with 26 % having a right rectus abdominis stripping injury with concomitant strain at the adductor longus musculotendinous junction. 7 % of patients had mild nonspecific edema in the distal bilateral rectus abdominis muscles without evidence of a tear. Twenty patients had no findings on their preoperative MRI, and only one patient was noted to have an inguinal hernia on MRI. All patients underwent laparoscopic totally extraperitoneal inguinal hernia repair with synthetic mesh and ipsilateral adductor longus tenotomy. All patients were able to return to full sports-related activity in 24 days (range 21-28 days). One patient experienced urinary retention and another sustained an adductor brevis hematoma 3 months after completion of rehabilitation and surgical intervention. Mean follow up was 18 months. Athletic pubalgia is a disease with a multifactorial etiology that can be treated surgically by a laparoscopic totally extraperitoneal hernia repair with synthetic mesh accompanied with an ipsilateral adductor longus tenotomy allowing patients to return to sports-related activity early with

Growth hormone secretagogues prevent dysregulation of skeletal muscle calcium homeostasis in a rat model of cisplatin-induced cachexia.

Science.gov (United States)

Conte, Elena; Camerino, Giulia Maria; Mele, Antonietta; De Bellis, Michela; Pierno, Sabata; Rana, Francesco; Fonzino, Adriano; Caloiero, Roberta; Rizzi, Laura; Bresciani, Elena; Ben Haj Salah, Khoubaib; Fehrentz, Jean-Alain; Martinez, Jean; Giustino, Arcangela; Mariggiò, Maria Addolorata; Coluccia, Mauro; Tricarico, Domenico; Lograno, Marcello Diego; De Luca, Annamaria; Torsello, Antonio; Conte, Diana; Liantonio, Antonella

2017-06-01

Cachexia is a wasting condition associated with cancer types and, at the same time, is a serious and dose-limiting side effect of cancer chemotherapy. Skeletal muscle loss is one of the main characteristics of cachexia that significantly contributes to the functional muscle impairment. Calcium-dependent signaling pathways are believed to play an important role in skeletal muscle decline observed in cachexia, but whether intracellular calcium homeostasis is affected in this situation remains uncertain. Growth hormone secretagogues (GHS), a family of synthetic agonists of ghrelin receptor (GHS-R1a), are being developed as a therapeutic option for cancer cachexia syndrome; however, the exact mechanism by which GHS interfere with skeletal muscle is not fully understood. By a multidisciplinary approach ranging from cytofluorometry and electrophysiology to gene expression and histology, we characterized the calcium homeostasis in fast-twitch extensor digitorum longus (EDL) muscle of adult rats with cisplatin-induced cachexia and established the potential beneficial effects of two GHS (hexarelin and JMV2894) at this level. Additionally, in vivo measures of grip strength and of ultrasonography recordings allowed us to evaluate the functional impact of GHS therapeutic intervention. Cisplatin-treated EDL muscle fibres were characterized by a ~18% significant reduction of the muscle weight and fibre diameter together with an up-regulation of atrogin1/Murf-1 genes and a down-regulation of Pgc1-a gene, all indexes of muscle atrophy, and by a two-fold increase in resting intracellular calcium, [Ca 2+ ] i , compared with control rats. Moreover, the amplitude of the calcium transient induced by caffeine or depolarizing high potassium solution as well as the store-operated calcium entry were ~50% significantly reduced in cisplatin-treated rats. Calcium homeostasis dysregulation parallels with changes of functional ex vivo (excitability and resting macroscopic conductance) and in

Effects of Preventative Ankle Taping on Planned Change-of-Direction and Reactive Agility Performance and Ankle Muscle Activity in Basketballers

Directory of Open Access Journals (Sweden)

Matthew D. Jeffriess, Adrian B. Schultz, Tye S. McGann, Samuel J. Callaghan, Robert G. Lockie

2015-12-01

Full Text Available This study investigated the effects of preventative ankle taping on planned change-of-direction and reactive agility performance and peak ankle muscle activity in basketballers. Twenty male basketballers (age = 22.30 ± 3.97 years; height = 1.84 ± 0.09 meters; body mass = 85.96 ± 11.88 kilograms with no ankle pathologies attended two testing sessions. Within each session, subjects completed six planned and six reactive randomized trials (three to the left and three to the right for each condition of the Y-shaped agility test, which was recorded by timing lights. In one session, subjects had both ankles un-taped. In the other, both ankles were taped using a modified subtalar sling. Peak tibialis anterior, peroneus longus (PL, peroneus brevis (PB, and soleus muscle activity was recorded for both the inside and outside legs across stance phase during the directional change, which was normalized against 10-meter sprint muscle activity (nEMG. Both the inside and outside cut legs during the change-of-direction step were investigated. Repeated measures ANOVA determined performance time and nEMG differences between un-taped and taped conditions. There were no differences in planned change-of-direction or reactive agility times between the conditions. Inside cut leg PL nEMG decreased when taped for the planned left, reactive left, and reactive right cuts (p = 0.01. Outside leg PB and soleus nEMG increased during the taped planned left cut (p = 0.02. There were no other nEMG changes during the cuts with taping. Taping did not affect change-of-direction or agility performance. Inside leg PL activity was decreased, possibly due to the tape following the line of muscle action. This may reduce the kinetic demand for the PL during cuts. In conclusion, ankle taping did not significantly affect planned change-of-direction or reactive agility performance, and did not demonstrate large changes in activity of the muscle complex in healthy basketballers.

Effects of thyroid hormone on Na+-K+ transport in resting and stimulated rat skeletal muscle

International Nuclear Information System (INIS)

Everts, M.E.; Clausen, T.

1988-01-01

The effects of hypothyroidism and 3,5,3'-triiodothyronine (T 3 ) treatment on passive Na + -K + fluxes and Na + -K + pump concentration were investigated in isolated rat muscle. Within 12 h after a single dose of T 3 (20 μg/100 g body wt), K + efflux had increased by 21% in soleus and by 20% in extensor digitorum longus muscle. In the presence of ouabain, even larger effects were observed. These changes were associated with a 12% rise in amiloride-suppressible Na + influx but no significant increase in [ 3 H]ouabain binding site concentration. After 3 days of T 3 treatment, the stimulating effect on K + efflux and Na + influx in soleus reached a plateau ∼80 and 40% above control levels, respectively, whereas the maximum increase in [ 3 H]ouabain binding site concentration (103%) was only fully developed after 8 days. Hypothyroidism decreased 86 Rb efflux by 30%. The efflux of K + and the influx of Na + per contraction (both ∼7 nmol/g wet wt) as well as the net loss of K + induced by electrical stimulation were unaffected by T 3 treatment. The rise in resting K + efflux after 12-24 h of T 3 treatment could be partly blocked by dantrolene or trifluoroperazine, indicating that an increase in the cytoplasmic Ca 2+ concentration may contribute to the early rise in K + efflux. It is concluded that the early rise in the resting passive leaks of Na + and K + induced by T 3 is a major driving force for Na + -K + pump synthesis

Muscle Deoxygenation Causes Muscle Fatigue

Science.gov (United States)

Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D.

1999-01-01

Muscle fatigue is a common musculoskeletal disorder in the work place, and may be a harbinger for more disabling cumulative trauma disorders. Although the cause of fatigue is multifactorial, reduced blood flow and muscle oxygenation may be the primary factor in causing muscle fatigue during low intensity muscle exertion. Muscle fatigue is defined as a reduction in muscle force production, and also occurs among astronauts who are subjected to postural constraints while performing lengthy, repetitive tasks. The objectives of this research are to: 1) develop an objective tool to study the role of decreased muscle oxygenation on muscle force production, and 2) to evaluate muscle fatigue during prolonged glovebox work.

Timing of muscle response to a sudden leg perturbation: comparison between adolescents and adults with Down syndrome.

Directory of Open Access Journals (Sweden)

Maria Stella Valle

Full Text Available Movement disturbances associated with Down syndrome reduce mechanical stability, worsening the execution of important tasks such as walking and upright standing. To compensate these deficits, persons with Down syndrome increase joint stability modulating the level of activation of single muscles or producing an agonist-antagonist co-activation. Such activations are also observed when a relaxed, extended leg is suddenly released and left to oscillate passively under the influence of gravity (Wartenberg test. In this case, the Rectus femoris of adults with Down syndrome displayed peaks of activation after the onset of the first leg flexion. With the aim to verify if these muscular reactions were acquired during the development time and to find evidences useful to give them a functional explanation, we used the Wartenberg test to compare the knee joint kinematics and the surface electromyography of the Rectus femoris and Biceps femoris caput longus between adolescents and adults with Down syndrome. During the first leg flexion, adolescents and adults showed single Rectus femoris activations while, a restricted number of participants exhibited agonist-antagonist co-activations. However, regardless the pattern of activation, adults initiated the muscle activity significantly later than adolescents. Although most of the mechanical parameters and the total movement variability were similar in the two groups, the onset of the Rectus femoris activation was well correlated with the time of the minimum acceleration variability. Thus, in adolescents the maximum mechanical stability occurred short after the onset of the leg fall, while adults reached their best joint stability late during the first flexion. These results suggest that between the adolescence and adulthood, persons with Down syndrome explore a temporal window to select an appropriate timing of muscle activation to overcome their inherent mechanical instability.

"Proprioceptive signature" of cursive writing in humans: a multi-population coding.

Science.gov (United States)

Roll, Jean-Pierre; Albert, Frédéric; Ribot-Ciscar, Edith; Bergenheim, Mikael

2004-08-01

The goal of the present study was to investigate the firing behavior of populations of muscle spindle afferents in all the muscles acting on the ankle while this joint was being subjected to "writing-like" movements. First it was proposed to determine whether the ensemble of muscle spindles give rise to a unique, specific, and reproducible feedback information characterizing each letter, number or short word. Secondly, we analyzed how the proprioceptive feedback on the whole encodes the spatial and temporal characteristics of writing movements using the "vector population model". The unitary activity of 51 primary and secondary muscle spindle afferents was recorded in the tibial and common peroneal nerves at the level of the popliteal fossea, using the microneurographic method. The units recorded from belonged to the tibialis anterior, the extensor digitorum longus, the extensor hallucis longus, the peroneus lateralis, the gastrocnemius-soleus and the tibialis posterior muscles. The "writing-like" movements were randomly imposed at a "natural" velocity via a computer-controlled machine in a two-dimensional space. In general, muscle spindle afferents from any of the six muscles responded according to the tuning properties of the parent muscle, i.e. increasing their discharge rate during the phases where the direction of movement was within the preferred sensory sector of the parent muscle. The whole trajectory of the writing movements was coded in turn by the activity of Ia afferents arising from all the muscles acting on the joint. Both single afferent responses and population responses were found to be highly specific and reproducible with each graphic sign. The complex multi-muscle afferent pattern involved, with its timing and distribution in the muscle space, seems to constitute a true "proprioceptive signature" for each graphic symbol. The ensemble of muscle spindle afferents were therefore found to encode the instantaneous direction and velocity of writing

Pseudotear of the peroneus longus tendon on MRI, secondary to a fibrocartilaginous node

Energy Technology Data Exchange (ETDEWEB)

Didolkar, Manjiri M. [Harvard Medical School, Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA (United States); Malone, Alfred L. [Radiology of Huntsville, PC, Huntsville, AL (United States); Nunley, James A. [Duke University Medical Center, Department of Orthopaedic Surgery, Durham, NC (United States); Dodd, Leslie G. [Duke University Medical Center, Department of Pathology, Durham, NC (United States); Helms, Clyde A. [Duke University Medical Center, Department of Radiology, Durham, NC (United States)

2012-11-15

The purpose of this study was to identify the presence of a fibrocartilaginous node within the distal peroneus longus tendon (PLT) just proximal to the cubital tunnel and correlate this with MRI signal characteristics of the distal PLT, which could result in a pseudotear appearance on MRI. We correlated imaging characteristics with pathologic specimens. Institutional review board approval was obtained. Retrospectively, 91 ankle MRIs utilizing a standard ankle protocol were reviewed by two musculoskeletal radiologists. Four cadaver ankles were imaged using a standard ankle MRI protocol and reviewed by the same radiologists. All the MRIs were examined for signal changes in the PLT. The cadaver ankles then underwent PLT dissection by an orthopaedic surgeon, and a pathologic review was undertaken by a pathologist with orthopaedic specialization, who looked for an os peroneum or proposed fibrocartilaginous node relating to the signal change found on the MRIs. In the 91 ankle MRI studies, the PLT demonstrated normal low and increased signals. On the fat-saturated T2-weighted sequence, 76 (83.5%) ankles demonstrated low signal and 15 (16.5%) demonstrated increased signal. Of the cadaver ankle MRIs, all four demonstrated increased signal within the PLT; three contained a fibrocartilaginous node and one contained an os peroneum in that same region. The MRI signal of the PLT can change with the presence of a fibrocartilaginous node, which may be due to the molecular and chemical content of the fibrocartilage. This node increases the MRI signal in the distal PLT and gives the appearance of a pseudotear. (orig.)

Pseudotear of the peroneus longus tendon on MRI, secondary to a fibrocartilaginous node

International Nuclear Information System (INIS)

Didolkar, Manjiri M.; Malone, Alfred L.; Nunley, James A.; Dodd, Leslie G.; Helms, Clyde A.

2012-01-01

The purpose of this study was to identify the presence of a fibrocartilaginous node within the distal peroneus longus tendon (PLT) just proximal to the cubital tunnel and correlate this with MRI signal characteristics of the distal PLT, which could result in a pseudotear appearance on MRI. We correlated imaging characteristics with pathologic specimens. Institutional review board approval was obtained. Retrospectively, 91 ankle MRIs utilizing a standard ankle protocol were reviewed by two musculoskeletal radiologists. Four cadaver ankles were imaged using a standard ankle MRI protocol and reviewed by the same radiologists. All the MRIs were examined for signal changes in the PLT. The cadaver ankles then underwent PLT dissection by an orthopaedic surgeon, and a pathologic review was undertaken by a pathologist with orthopaedic specialization, who looked for an os peroneum or proposed fibrocartilaginous node relating to the signal change found on the MRIs. In the 91 ankle MRI studies, the PLT demonstrated normal low and increased signals. On the fat-saturated T2-weighted sequence, 76 (83.5%) ankles demonstrated low signal and 15 (16.5%) demonstrated increased signal. Of the cadaver ankle MRIs, all four demonstrated increased signal within the PLT; three contained a fibrocartilaginous node and one contained an os peroneum in that same region. The MRI signal of the PLT can change with the presence of a fibrocartilaginous node, which may be due to the molecular and chemical content of the fibrocartilage. This node increases the MRI signal in the distal PLT and gives the appearance of a pseudotear. (orig.)

Use of superficial peroneal nerve graft for treating peripheral nerve injuries

Directory of Open Access Journals (Sweden)

Samuel Ribak

2016-02-01

Full Text Available ABSTRACT OBJECTIVE: To evaluate the clinical results from treating chronic peripheral nerve injuries using the superficial peroneal nerve as a graft donor source. METHODS: This was a study on eleven patients with peripheral nerve injuries in the upper limbs that were treated with grafts from the sensitive branch of the superficial peroneal nerve. The mean time interval between the dates of the injury and surgery was 93 days. The ulnar nerve was injured in eight cases and the median nerve in six. There were three cases of injury to both nerves. In the surgery, a longitudinal incision was made on the anterolateral face of the ankle, thus viewing the superficial peroneal nerve, which was located anteriorly to the extensor digitorum longus muscle. Proximally, the deep fascia between the extensor digitorum longus and the peroneal longus muscles was dissected. Next, the motor branch of the short peroneal muscle (one of the branches of the superficial peroneal nerve was identified. The proximal limit of the sensitive branch was found at this point. RESULTS: The average space between the nerve stumps was 3.8 cm. The average length of the grafts was 16.44 cm. The number of segments used was two to four cables. In evaluating the recovery of sensitivity, 27.2% evolved to S2+, 54.5% to S3 and 18.1% to S3+. Regarding motor recovery, 72.7% presented grade 4 and 27.2% grade 3. There was no motor deficit in the donor area. A sensitive deficit in the lateral dorsal region of the ankle and the dorsal region of the foot was observed. None of the patients presented complaints in relation to walking. CONCLUSIONS: Use of the superficial peroneal nerve as a graft source for treating peripheral nerve injuries is safe and provides good clinical results similar to those from other nerve graft sources.

Computed tomography of the carotid space and related cervical spaces. Part 1. Anatomy

International Nuclear Information System (INIS)

Silver, A.J.; Mawad, M.E.; Hilal, S.K.; Sane, P.; Ganti, S.R.

1984-01-01

The carotid space, parapharyngeal space, and paraspinal space are described. The carotid space is shown on computed tomography (CT) to be posterior to the parapharyngeal space and separated from it by the styloid apparatus. The paraspinal space is posterior to the carotid space and separated from it by the longus and anterior scalene muscles

[Development of a system for static measurement of skin-muscle hardness and a fundamental study on its applications].

Science.gov (United States)

Honda, T

1990-10-01

There have been many attempts to quantitatively measure the hardness of skin-muscle, but no objective method for doing so has been established, because there is no universal standard for the hardness of organisms. The author considered elasticity and viscosity as the most important mechanical properties of the hardness of skin-muscle and applied the Maxwell model, in which a spring and a dash-pot are arranged in a series, to the static mechanical behavior of skin-muscle. A relatively large globular pressing body with a radius of 5 mm was set as a transducer in the measuring system, so that the conformity of the practically measured values to those calculated theoretically by the model was increased. Strain of skin-muscle is expressed as a function of the load, which includes indices of elasticity (1/M) (M(N/mm2) = E/(1-lambda 2) (E: Young's modulus, lambda:Poisson's ratio)) and viscosity (1/eta) (eta:modulus of viscosity) in a particular region. Because hardness is defined as the degree of resistance against transformation by loading, decreases in the indices of both elasticity and viscosity mean increases of hardness. With 150 male and female office workers chosen as the subjects, the model was examined and the indices were calculated. The results were as follows. 1) Very good conformity of practically measured values to those calculated theoretically by the Maxwell model was recognized within the range of load velocity from 0.3 G to 3.0 G (N/sec). 2) In both males and females the regions with values nearest to those of a Newtonian fluid were, in descending order, the distal phalanxes of digiti 2-4, the palm, the distal phalanx of the first digitus and the arm. In reverse order these regions approached complete elasticity. 3) In males it was suggested that the element of viscosity in the region of the biceps brachii muscle and the hardness in the regions of the brachioradialis, the flexor carpi radialis and palmalis longus muscles and the distal phalanxes of the 4

Bone and muscular anatomy of the forearm and hand in Tapirus terrestris (Perissodactyla, Tapiridae

Directory of Open Access Journals (Sweden)

Saulo Gonçalves Pereira

2017-05-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2017v30n2p35 In Brazil, there are two species of tapirs, the largest land mammals in Brazil, which belong to the order Perissodactyla, as do horses. Our aim was to describe the bone and muscular anatomy of the forearm and hand in T. terrestris and to propose adaptive functions. We used five anatomical specimens donated from a breeder to the Laboratory for Teaching and Research on Wild Animals of the Federal University of Uberlandia after death with no trauma. The bones were analyzed, the muscles dissected, and both described. The bones of the forearm and hand of the tapir are the ulna, radius, Os. metacarpalia, Os. carpi, phalanx and Os. sesamoideum. The muscles are M. extensor carpi radialis, M. ulnaris lateralis; M. flexor carpi radialis; M. extensor radialis communis; M. extensor digitorum longus II, III, IV and V, M. extensor digitorum lateralis; M. extensor digitorum; M. abductor longus; M. flexor digiti superficialis; M. flexor digitalis; M. flexor carpi ulnaris; M. flexor carpi obliquus; and M. interossei and M. lumbricales. Characteristics of bone and muscle structure are adapted to the development of the animal’s niche.

Effect of anesthesia on glucose production and utilization in rats

International Nuclear Information System (INIS)

Penicaud, L.; Ferre, P.; Kande, J.; Leturque, A.; Issad, T.; Girard, J.

1987-01-01

This study was undertaken to determine the effects of pentobarbital anesthesia (50 mg/kg ip) on glucose kinetics and individual tissue glucose utilization in vivo, in chronically catheterized rats. Glucose turnover studies were carried out using [3- 3 H] glucose as tracer. A transient hyperglycemia and an increased glucose production were observed 3 min after induction of anesthesia. However, 40 min after induction of anesthesia, glycemia returned to the level observed in awake animals, whereas glucose turnover was decreased by 30% as compared with unanesthetized rats. These results are discussed with regard to the variations observed in plasma insulin, glucagon, and catecholamine levels. Glucose utilization by individual tissues was studied by the 2-[1- 3 H] deoxyglucose technique. A four- to fivefold decrease in glucose utilization was observed in postural muscles (soleus and adductor longus), while in other nonpostural muscles (epitrochlearis, tibialis anterior, extensor digitorum longus, and diaphragm) and other tissues (white and brown adipose tissues) anesthesia did not modify the rate of glucose utilization. A decrease in glucose utilization was also observed in the brain

Magnetic resonance imaging phenotyping of Becker muscular dystrophy.

Science.gov (United States)

Faridian-Aragh, Neda; Wagner, Kathryn R; Leung, Doris G; Carrino, John A

2014-12-01

There is little information on magnetic resonance imaging (MRI) phenotypes of Becker muscular dystrophy (BMD). This study presents the MRI phenotyping of the upper and lower extremities of a large cohort of BMD patients. In this retrospective study, MRI images of 33 BMD subjects were evaluated for severity, distribution, and symmetry of involvement. Teres major, triceps long head, biceps brachii long head, gluteus maximus, gluteus medius, vasti, adductor longus, adductor magnus, semitendinosus, semimembranosus, and biceps femoris muscles showed the highest severity and frequency of involvement. All analyzed muscles had a high frequency of symmetric involvement. There was significant variability of involvement between muscles within some muscle groups, most notably the arm abductors, posterior arm muscles, medial thigh muscles, and lateral hip rotators. This study showed a distinctive pattern of involvement of extremity muscles in BMD subjects. © 2014 Wiley Periodicals, Inc.

Isolation, Culture, Functional Assays, and Immunofluorescence of Myofiber-Associated Satellite Cells.

Science.gov (United States)

Vogler, Thomas O; Gadek, Katherine E; Cadwallader, Adam B; Elston, Tiffany L; Olwin, Bradley B

2016-01-01

Adult skeletal muscle stem cells, termed satellite cells, regenerate and repair the functional contractile cells in adult skeletal muscle called myofibers. Satellite cells reside in a niche between the basal lamina and sarcolemma of myofibers. Isolating single myofibers and their associated satellite cells provides a culture system that partially mimics the in vivo environment. We describe methods for isolating and culturing intact individual myofibers and their associated satellite cells from the mouse extensor digitorum longus muscle. Following dissection and isolation of individual myofibers we provide protocols for myofiber transplantation, satellite cell transfection, immune detection of satellite cell antigens, and assays to examine satellite cell self-renewal and proliferation.

Effect of wrist and interphalangeal thumb movement on zone T2 flexor pollicis longus tendon tension in a human cadaver model.

Science.gov (United States)

Rappaport, Patricia O; Thoreson, Andrew R; Yang, Tai-Hua; Reisdorf, Ramona L; Rappaport, Stephen M; An, Kai-Nan; Amadio, Peter C

2015-01-01

Therapy after flexor pollicis longus (FPL) repair typically mimics finger flexor management, but this ignores anatomic and biomechanical features unique to the FPL. We measured FPL tendon tension in zone T2 to identify biomechanically appropriate exercises for mobilizing the FPL. Eight human cadaver hands were studied to identify motions that generated enough force to achieve FPL movement without exceeding hypothetical suture strength. With the carpometacarpal and metacarpophalangeal joints blocked, appropriate forces were produced for both passive interphalangeal (IP) motion with 30° wrist extension and simulated active IP flexion from 0° to 35° with the wrist in the neutral position. This work provides a biomechanical basis for safely and effectively mobilizing the zone T2 FPL tendon. Our cadaver study suggests that it is safe and effective to perform early passive and active exercise to an isolated IP joint. NA. Copyright © 2015 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Differential glucose metabolism in mice and humans affected by McArdle disease

DEFF Research Database (Denmark)

Krag, Thomas O; Pinós, Tomàs; Nielsen, Tue L

2016-01-01

McArdle disease (muscle glycogenosis type V) is a disease caused by myophosphorylase deficiency leading to "blocked" glycogen breakdown. A significant but varying glycogen accumulation in especially distal hind limb muscles of mice affected by McArdle disease has recently been demonstrated......, which could lead to lower glycogen accumulation. In comparison, tibialis anterior, extensor digitorum longus, and soleus had massive glycogen accumulation, but few, if any, changes or adaptations in glucose metabolism compared with wild-type mice. The findings suggest plasticity in glycogen metabolism....... In this study, we investigated how myophosphorylase deficiency affects glucose metabolism in hind limb muscle of 20-wk-old McArdle mice and vastus lateralis muscles from patients with McArdle disease. Western blot analysis and activity assay demonstrated that glycogen synthase was inhibited in glycolytic muscle...

Neck Pain and Acute Dysphagia.

Science.gov (United States)

Simões, João; Romão, José; Cunha, Anita; Paiva, Sofia; Miguéis, António

2017-02-01

The acute tendinitis of the longus colli muscle is an unusual diagnosis in the cases of acute dysphagia with cervical pain. Is a self-limiting condition caused by abnormal calcium hydroxyapatite deposition in the prevertebral space and can cause pharyngeal swelling with impaired swallow. It is absolutely critical to make the differential diagnosis with deep cervical infections in order to avoid invasive treatments.

Proportions of myosin heavy chain mRNAs, protein isoforms and fiber types in the slow and fast skeletal muscles are maintained after alterations of thyroid status in rats.

Science.gov (United States)

Soukup, T; Diallo, M

2015-01-01

Recently, we have established that slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles of euthyroid (EU) Lewis rats posses the same proportions between their four myosin heavy chain (MyHC) mRNAs, protein isoforms and fiber types as determined by real time RT-PCR, SDS-PAGE and 2-D stereological fiber type analysis, respectively. In the present paper we investigated if these proportions are maintained in adult Lewis rats with hyperthyroid (HT) and hypothyroid (HY) status. Although HT and HY states change MyHC isoform expression, results from all three methods showed that proportion between MyHC mRNA-1, 2a, -2x/d, -2b, protein isoforms MyHC-1, -2a, -2x/d, -2b and to lesser extent also fiber types 1, 2A, 2X/D, 2B were preserved in both SOL and EDL muscles. Furthermore, in the SOL muscle mRNA expression of slow MyHC-1 remained up to three orders higher compared to fast MyHC transcripts, which explains the predominance of MyHC-1 isoform and fiber type 1 even in HT rats. Although HT status led in the SOL to increased expression of MyHC-2a mRNA, MyHC-2a isoform and 2A fibers, it preserved extremely low expression of MyHC-2x and -2b mRNA and protein isoforms, which explains the absence of pure 2X/D and 2B fibers. HY status, on the other hand, almost completely abolished expression of all three fast MyHC mRNAs, MyHC protein isoforms and fast fiber types in the SOL muscle. Our data present evidence that a correlation between mRNA, protein content and fiber type composition found in EU status is also preserved in HT and HY rats.

Two zero-flow pressure intercepts exist in autoregulating isolated skeletal muscle.

Science.gov (United States)

Braakman, R; Sipkema, P; Westerhof, N

1990-06-01

The autoregulating vascular bed of the isolated canine extensor digitorum longus muscle was investigated for the possible existence of two positive zero-flow pressure axis intercepts, a tone-dependent one and a tone-independent one. An isolated preparation, perfused with autologous blood, was used to exclude effects of collateral flow and nervous and humoral regulation while autoregulation was left intact [mean autoregulatory gain 0.50 +/- 0.24 (SD)]. In a first series of experiments, the steady-state (zero flow) pressure axis intercept [mean 8.9 +/- 2.6 (SD) mmHg, tone independent] and the instantaneous (zero flow) pressure axis intercept [mean 28.5 +/- 9.9 (SD) mmHg, tone dependent] were determined as a function of venous pressure (range: 0-45 mmHg) and were independent of venous pressure until the venous pressure exceeded their respective values. Beyond this point the relations between the venous pressure and the steady-state and instantaneous pressure axis intercept followed the line of identity. The findings agree with the predictions of the vascular waterfall model. In a second series it was shown by means of administration of vasoactive drugs that the instantaneous pressure axis intercept is tone dependent, whereas the steady-state pressure axis intercept is not. It is concluded that there is a (proximal) tone-dependent zero-flow pressure at the arteriolar level and a (distal) tone-independent zero-flow pressure at the venous level.

A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

Science.gov (United States)

Randolph, Matthew E.; Pavlath, Grace K.

2015-01-01

The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies (MDs), such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some MDs. The biology of muscle stem cells varies depending on the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease. PMID:26500547

Temperature-dependent changes in the viscoelasticity of intact resting mammalian (rat) fast- and slow-twitch muscle fibres.

Science.gov (United States)

Mutungi, G; Ranatunga, K W

1998-04-01

1. The tension and sarcomere length responses induced by ramp stretches (at amplitudes of 1-3 % fibre length (Lo) and speeds of 0.01-12 Lo s-1) were examined at different temperatures (range, 10-35 degrees C) in resting intact muscle fibre bundles isolated from the soleus (a slow-twitch muscle) and extensor digitorum longus (a fast-twitch muscle) of the rat. Some observations are also presented on the effects of chemical skinning on passive viscoelasticity at 10 degrees C. 2. As previously reported, the tension response to a ramp stretch, in different preparations and under various conditions, could be resolved into a viscous (P1), a viscoelastic (P2) and an elastic (P3) component and showed characteristic differences between slow and fast muscle fibres. 3. Chemical skinning of the muscle fibres led to a decrease in the amplitude of all three tension components. However, the fast-slow fibre differences remained after skinning. For example, the viscosity coefficient derived from P1 tension data decreased from 0.84 +/- 0.06 before skinning to 0.44 +/- 0.06 kN s m-2 after skinning in fast fibres; the corresponding values in slow fibres were 2.1 +/- 0.08 and 0.87 +/- 0.09 kN s m-2, respectively. 4. Increasing the experimental temperature from 10 to 35 degrees C led to a decrease in all the tension components in both fast and slow muscle fibre bundles. The decrease of P1 (viscous) tension was such that the viscosity coefficient calculated using P1 data was reduced from 0.84 +/- 0.1 to 0.43 +/- 0.05 kN s m-2 in fast fibres and from 2.0 +/- 0.1 to 1.0 +/- 0.1 kN s m-2 in slow fibres (Q10 of approximately 1.3 in both). 5. In both fast and slow muscle fibre preparations, the plateau tension of the viscoelastic component (P2) decreased by 60-80 % as the temperature was increased from 10 to 35 degrees C giving P2 tension a Q10 of approximately 1.4 in slow fibres and approximately 1.7 in the fast fibres. Additionally, the relaxation time of the viscoelasticity decreased from

Different ankle muscle coordination patterns and co-activation during quiet stance between young adults and seniors do not change after a bout of high intensity training.

Science.gov (United States)

Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

2015-03-04

Available evidence suggests that young adults and seniors use different strategies to adjust for increasing body sway during quiet standing. Altered antagonist muscle co-activation and different ankle muscle coordination patterns may account for this finding. Consequently, we aimed at addressing whether aging leads to changes in neuromuscular coordination patterns as well as co-activation during quiet stance. We additionally investigated whether a bout of high intensity interval training additionally alters these patterns. Twenty healthy seniors (age: 70 ± 4 y) and twenty young adults (age: 27 ± 3 y) were enrolled in the present study. In between the testing procedures, four consecutive high-intensity intervals of 4 min duration at a target exercise intensity of 90 to 95% HRmax were completed on a treadmill. The total center of pressure (COP) path length displacement served as standing balance performance outcome. In order to assess ankle muscle coordination patterns, amplitude ratios (AR) were calculated for each muscle (e.g. tibialis anterior (TA) [%] = (TA × 100)/(gastrocnemius medialis (GM) + soleus (SOL) + peroneus longus (PL) + TA). The co-activation was calculated for the SOL and TA muscles computing the co-activation index (CAI = 2 × TA/TA + SOL). Seniors showed an inverted ankle muscle coordination pattern during single limb stance with eyes open (SLEO), compared to young adults (rest: GM, S: 15 ± 8% vs Y: 24 ± 9%; p = 0.03; SOL, S: 27 ± 14% vs Y: 37 ± 18%; p = 0.009; TA, S: 31 ± 13% vs Y: 13 ± 7%; p = 0.003). These patterns did not change after a high-intensity training session. A moderate correlation between amplitude ratios of the TA-contribution and postural sway was observed for seniors during SLEO (r = 0.61). Ankle co-activation was twofold elevated in seniors compared to young adults during SLEO (p Seniors with decreased postural control showed higher TA

The change in deep cervical flexor activity after training is associated with the degree of pain reduction in patients with chronic neck pain.

Science.gov (United States)

Falla, Deborah; O'Leary, Shaun; Farina, Dario; Jull, Gwendolen

2012-09-01

Altered activation of the deep cervical flexors (longus colli and longus capitis) has been found in individuals with neck pain disorders but the response to training has been variable. Therefore, this study investigated the relationship between change in deep cervical flexor muscle activity and symptoms in response to specific training. Fourteen women with chronic neck pain undertook a 6-week program of specific training that consisted of a craniocervical flexion exercise performed twice per day (10 to 20 min) for the duration of the trial. The exercise targets the deep flexor muscles of the upper cervical region. At baseline and follow-up, measures were taken of neck pain intensity (visual analogue scale, 0 to 10), perceived disability (Neck Disability Index, 0 to 50) and electromyography (EMG) of the deep cervical flexors (by a nasopharyngeal electrode suctioned over the posterior oropharyngeal wall) during performance of craniocervical flexion. After training, the activation of the deep cervical flexors increased (Pcervical flexor EMG amplitude at baseline (R(2)=0.68; Ppain intensity, change in pain level with training, and change in EMG amplitude for the deep cervical flexors during craniocervical flexion (R(2)=0.34; Pcervical flexor muscles in women with chronic neck pain reduces pain and improves the activation of these muscles, especially in those with the least activation of their deep cervical flexors before training. This finding suggests that the selection of exercise based on a precise assessment of the patients' neuromuscular control and targeted exercise interventions based on this assessment are likely to be the most beneficial to patients with neck pain.

Bilateral posterior tarsal tunnel syndrome caused by accessory flexor digitorum longus; case report and surgical technique.

Science.gov (United States)

Schmidt-Hebbel, A; Elgueta, J; Villa, A; Mery, P; Filippi, J

To present a case report of bilateral posterior tarsal tunnel syndrome (PTTS) caused by an accessory flexor digitorum longus (AFDL), including the surgical technique and a review of the literature. Twenty-nine year old male diagnosed with bilateral PTTS, refractory to conservative management, with 53 points on the preoperative AOFAS score. MR of both ankles showed an AFDL within the tarsal tunnel, in close relationship to the posterior tibial nerve. Bilateral tarsal tunnel decompression and AFDL resection was performed. There were no post-operative complications. At 6 months after surgery, the patient had no pain and had 87 points on the AOFAS score. The PTTS is an entrapment neuropathy of the posterior tibial nerve or one of its terminal branches. A rare cause is the presence of an AFDL, and its resection is associated with good clinical results. Careful scar tissue resection and neurolysis is recommended. Knowing the normal pathway and anatomical variability of the posterior tibial nerve and its branches is essential to avoid iatrogenic injury. In our case report, MR and intraoperative findings identified a bilateral FDLA in close relationship to the common flexor digitorum, an unusual finding, with few reports in current literature. Careful tarsal tunnel decompression and AFDL resection in our patient with bilateral symptomatic PTTS has good clinical results and no complications, particularly when diagnosed and treated early. Copyright © 2015 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Levels of myosin heavy chain mRNA transcripts and protein isoforms in the fast extensor digitorum longus muscle of 7-month-old rats with chronic thyroid status alterations

Czech Academy of Sciences Publication Activity Database

Vadászová, Adriana; Hudecová, S.; Križanová, O.; Soukup, Tomáš

2006-01-01

Roč. 55, č. 6 (2006), s. 707-710 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA304/05/0327 Grant - others:VEGA(SK) 2/4106; NATO(XE) 979876; SAV(SK) APVT-51-027404; MYORES(XE) 511978 Institutional research plan: CEZ:AV0Z50110509 Keywords : myosin heavy chain isoforms * thyroid hormones * muscle differentiation Subject RIV: ED - Physiology Impact factor: 2.093, year: 2006

Success of nonoperative management of adductor longus tendon ruptures in National Football League athletes.

Science.gov (United States)

Schlegel, Theodore F; Bushnell, Brandon D; Godfrey, Jenna; Boublik, Martin

2009-07-01

Acute complete ruptures of the proximal adductor longus tendon are rare but challenging injuries to treat. The limited literature supports operative treatment, but data from management of chronic groin pain in athletes indicate that anatomical attachment of the tendon to the pubis may not be required for high-level function. Nonoperative management of complete adductor rupture can provide equal results to surgical repair in terms of return to play in the National Football League. Case series; Level of evidence, 4. Using the National Football League Injury Surveillance System, adductor tendon ruptures documented by magnetic resonance imaging were identified in 19 National Football League players from 1992 to 2004. The team physician for each respective player completed a survey with information about history, physical examination, magnetic resonance imaging findings, treatment, and outcomes. Statistics were analyzed with a Student unpaired t test. Fourteen players were treated nonoperatively, and 5 players were treated with surgical repair using suture anchors. In both groups, all players eventually returned to play in the National Football League. Mean time for return to play was 6.1 +/- 3.1 weeks (range, 3-12 weeks) for the nonoperative group and 12.0 +/- 2.5 weeks (range, 10-16 weeks) for the operative group (P = .001). One player in the operative group suffered the complication of a draining wound and heterotopic ossification. Players represented a variety of positions, and 12 of 19 (63%) had experienced prior symptoms or events. Nonoperative treatment of proximal adductor tendon rupture results in a statistically significantly faster return to play than does operative treatment in athletes competing in the National Football League and avoids the risks associated with surgery while providing an equal likelihood of return to play at the professional level.

Cold water immersion of the ankle decreases neuromuscular response of lower limb after inversion movement

OpenAIRE

Macedo, Christiane S. G.; Alonso, Carolina S.; Liporaci, Rogério F.; Vieira, Fernando; Guirro, Rinaldo R. J.

2014-01-01

BACKGROUND: Cryotherapy has been associated with a significant decrease in nerve conduction velocity and muscle contraction with possible effects on exercise and physical training. OBJECTIVES: To quantify the electromyographic response of the lateral gastrocnemius, tibialis anterior, fibularis longus, rectus femoris and gluteus medius to ankle inversion following cold water immersion. METHOD: The peak values of the root mean square (RMS) were obtained from 35 healthy and active univ...

THE CORRECTION OF HALLUX VARUS DEFORMITY IN CONSEQUENCE OF SURGICAL TREATMENT FOR HALLUX VALGUS

Directory of Open Access Journals (Sweden)

V. M. Mashkov

2010-01-01

Full Text Available The analysis of treatment of 21 patients (24 feet with postoperative hallux varus deformity which have arisen after operations apropos hallux valgus is carried out. For correction of vicious position of the first finger we successfully carried out the Brandes procedure, sometimes in a combination to operations on sinews of muscles of the first finger - an adductor hallucis tendotomy and/or lengthening of the extensor hallucis longus tendon.

Análisis de imágenes de fibras musculares oxidativas y glucolíticas durante la reperfusión mediante segmentación basada en regiones

OpenAIRE

Rosero Salazar, Doris Haydee

2016-01-01

Different situations cause ischemia and reperfusion injury, affecting tissues under the level of compression. In this research, abnormal characteristics in distribution of muscle fibers types in soleus and extensor carpi radialis longus, during short periods of ischemia and short and long periods of reperfusion, were determined. Fibers were classified by enzyme histochemistry techniques NADH-TR and myosin-ATPase. Measurements of areas were carried out through semiautomatic image processing by...

Effects of thyroid hormone on Na sup + -K sup + transport in resting and stimulated rat skeletal muscle

Energy Technology Data Exchange (ETDEWEB)

Everts, M.E.; Clausen, T. (Aarhus Univ. (Denmark))

1988-11-01

The effects of hypothyroidism and 3,5,3{prime}-triiodothyronine (T{sub 3}) treatment on passive Na{sup +}-K{sup +} fluxes and Na{sup +}-K{sup +} pump concentration were investigated in isolated rat muscle. Within 12 h after a single dose of T{sub 3} (20 {mu}g/100 g body wt), K{sup +} efflux had increased by 21% in soleus and by 20% in extensor digitorum longus muscle. In the presence of ouabain, even larger effects were observed. These changes were associated with a 12% rise in amiloride-suppressible Na{sup +} influx but no significant increase in ({sup 3}H)ouabain binding site concentration. After 3 days of T{sub 3} treatment, the stimulating effect on K{sup +} efflux and Na{sup +} influx in soleus reached a plateau {approximately}80 and 40% above control levels, respectively, whereas the maximum increase in ({sup 3}H)ouabain binding site concentration (103%) was only fully developed after 8 days. Hypothyroidism decreased {sup 86}Rb efflux by 30%. The efflux of K{sup +} and the influx of Na{sup +} per contraction (both {approximately}7 nmol/g wet wt) as well as the net loss of K{sup +} induced by electrical stimulation were unaffected by T{sub 3} treatment. The rise in resting K{sup +} efflux after 12-24 h of T{sub 3} treatment could be partly blocked by dantrolene or trifluoroperazine, indicating that an increase in the cytoplasmic Ca{sup 2+} concentration may contribute to the early rise in K{sup +} efflux. It is concluded that the early rise in the resting passive leaks of Na{sup +} and K{sup +} induced by T{sub 3} is a major driving force for Na{sup +}-K{sup +} pump synthesis.

The frondiform ligament and pseudotenosynovitis of the extensor digitorum longus tendon: MRI evaluation with cadaveric correlation

International Nuclear Information System (INIS)

Zember, Jonathan; Rosenberg, Zehava; Mba-Jones, Chimere; Bencardino, Jenny; Rossi, Ignacio

2016-01-01

Fluid along the frondiform ligament, the sinus tarsi stem of the inferior extensor retinaculum (IER), can approximate the extensor digitorum longus (EDL), at times simulating tenosynovitis. Our purpose, based on MRI and cadaveric studies, was to further evaluate this scantly described phenomenon, to identify associated findings and to alert the radiologists to the potential pitfall of over diagnosing EDL tenosynovitis. Two musculoskeletal radiologists retrospectively reviewed the radiology reports and MRI studies of 258 ankle MRI exams, performed at our institution, for fluid along the frondiform ligament extending toward the EDL. No patient had EDL pathology clinically. MRI was performed in two cadaveric ankles following injection of the sinus tarsi and EDL tendon sheath, under ultrasound guidance. Altogether, 31 MRIs demonstrated fluid extending from the sinus tarsi along the frondiform ligament toward the EDL. In 30 cases (97 %), the fluid partially surrounded the tendon, without tendon sheath distension. Based on the radiology reports, in 11 of the 31 cases (35 %), the fluid was misinterpreted as abnormal. Most common associated findings included ligamentous injury, posterior tibial tendon (PTT) tear, flat-foot, and osteoarthrosis. In the cadavers, fluid extended along the frondiform ligament toward the EDL after sinus tarsi injection; there was no communication between EDL tendon sheath and the sinus tarsi. Fluid within the sinus tarsi can extend along the frondiform ligament and partially surround the EDL, manifesting as pseudotenosynovitis. This phenomenon, often seen with ligamentous tears or PTT dysfunction, should not be misdiagnosed as true pathology of the EDL. (orig.)

CORRELATIONS BETWEEN MUSCLE MASS, MUSCLE STRENGTH, PHYSICAL PERFORMANCE, AND MUSCLE FATIGUE RESISTANCE IN COMMUNITY-DWELLING ELDERLY SUBJECTS

Directory of Open Access Journals (Sweden)

Elizabeth

2016-03-01

Full Text Available Objective: To determine the correlations between muscle mass, muscle strength, physical performance, and muscle fatigue resistance in community-dwelling elderly people in order to elucidate factors which contribute to elderly’s performance of daily activities. Methods: A cross-sectional study was conducted on community-dwelling elderly in Bandung from September to December 2014. One hundred and thirty elderly, 60 years old or above, were evaluated using bioelectrical impedance analysis to measure muscle mass; grip strength to measure muscle strength and muscle fatigue resistance; habitual gait speed to measure physical performance; and Global Physical Activity Questionnaire (GPAQ to assess physical activity. Results: There were significant positive correlations between muscle mass (r=0,27, p=0,0019, muscle strength (r=0,26, p=0,0024, and physical performance (r=0,32, p=0,0002 with muscle fatigue resistance. Physical performance has the highest correlation based on multiple regression test (p=0,0025. In association with muscle mass, the physical activity showed a significant positive correlation (r=0,42, p=0,0000. Sarcopenia was identified in 19 (14.61% of 130 subjects. Conclusions: It is suggested that muscle mass, muscle strength, and physical performance influence muscle fatigue resistance.

Force encoding in muscle spindles during stretch of passive muscle.

Directory of Open Access Journals (Sweden)

Kyle P Blum

2017-09-01

Full Text Available Muscle spindle proprioceptive receptors play a primary role in encoding the effects of external mechanical perturbations to the body. During externally-imposed stretches of passive, i.e. electrically-quiescent, muscles, the instantaneous firing rates (IFRs of muscle spindles are associated with characteristics of stretch such as length and velocity. However, even in passive muscle, there are history-dependent transients of muscle spindle firing that are not uniquely related to muscle length and velocity, nor reproduced by current muscle spindle models. These include acceleration-dependent initial bursts, increased dynamic response to stretch velocity if a muscle has been isometric, and rate relaxation, i.e., a decrease in tonic IFR when a muscle is held at a constant length after being stretched. We collected muscle spindle spike trains across a variety of muscle stretch kinematic conditions, including systematic changes in peak length, velocity, and acceleration. We demonstrate that muscle spindle primary afferents in passive muscle fire in direct relationship to muscle force-related variables, rather than length-related variables. Linear combinations of whole muscle-tendon force and the first time derivative of force (dF/dt predict the entire time course of transient IFRs in muscle spindle Ia afferents during stretch (i.e., lengthening of passive muscle, including the initial burst, the dynamic response to lengthening, and rate relaxation following lengthening. Similar to acceleration scaling found previously in postural responses to perturbations, initial burst amplitude scaled equally well to initial stretch acceleration or dF/dt, though later transients were only described by dF/dt. The transient increase in dF/dt at the onset of lengthening reflects muscle short-range stiffness due to cross-bridge dynamics. Our work demonstrates a critical role of muscle cross-bridge dynamics in history-dependent muscle spindle IFRs in passive muscle

Force encoding in muscle spindles during stretch of passive muscle.

Science.gov (United States)

Blum, Kyle P; Lamotte D'Incamps, Boris; Zytnicki, Daniel; Ting, Lena H

2017-09-01

Muscle spindle proprioceptive receptors play a primary role in encoding the effects of external mechanical perturbations to the body. During externally-imposed stretches of passive, i.e. electrically-quiescent, muscles, the instantaneous firing rates (IFRs) of muscle spindles are associated with characteristics of stretch such as length and velocity. However, even in passive muscle, there are history-dependent transients of muscle spindle firing that are not uniquely related to muscle length and velocity, nor reproduced by current muscle spindle models. These include acceleration-dependent initial bursts, increased dynamic response to stretch velocity if a muscle has been isometric, and rate relaxation, i.e., a decrease in tonic IFR when a muscle is held at a constant length after being stretched. We collected muscle spindle spike trains across a variety of muscle stretch kinematic conditions, including systematic changes in peak length, velocity, and acceleration. We demonstrate that muscle spindle primary afferents in passive muscle fire in direct relationship to muscle force-related variables, rather than length-related variables. Linear combinations of whole muscle-tendon force and the first time derivative of force (dF/dt) predict the entire time course of transient IFRs in muscle spindle Ia afferents during stretch (i.e., lengthening) of passive muscle, including the initial burst, the dynamic response to lengthening, and rate relaxation following lengthening. Similar to acceleration scaling found previously in postural responses to perturbations, initial burst amplitude scaled equally well to initial stretch acceleration or dF/dt, though later transients were only described by dF/dt. The transient increase in dF/dt at the onset of lengthening reflects muscle short-range stiffness due to cross-bridge dynamics. Our work demonstrates a critical role of muscle cross-bridge dynamics in history-dependent muscle spindle IFRs in passive muscle lengthening conditions

Painful unilateral temporalis muscle enlargement: reactive masticatory muscle hypertrophy.

Science.gov (United States)

Katsetos, Christos D; Bianchi, Michael A; Jaffery, Fizza; Koutzaki, Sirma; Zarella, Mark; Slater, Robert

2014-06-01

An instance of isolated unilateral temporalis muscle hypertrophy (reactive masticatory muscle hypertrophy with fiber type 1 predominance) confirmed by muscle biopsy with histochemical fiber typing and image analysis in a 62 year-old man is reported. The patient presented with bruxism and a painful swelling of the temple. Absence of asymmetry or other abnormalities of the craniofacial skeleton was confirmed by magnetic resonance imaging and cephalometric analyses. The patient achieved symptomatic improvement only after undergoing botulinum toxin injections. Muscle biopsy is key in the diagnosis of reactive masticatory muscle hypertrophy and its distinction from masticatory muscle myopathy (hypertrophic branchial myopathy) and other non-reactive causes of painful asymmetric temporalis muscle enlargement.

Evaluation of muscle hyperactivity of the grimacing muscles by unilateral tight eyelid closure and stapedius muscle tone.

Science.gov (United States)

Shiba, Masato; Matsuo, Kiyoshi; Ban, Ryokuya; Nagai, Fumio

2012-10-01

Muscle hyperactivity of grimacing muscles, including the orbicularis oculi and corrugator supercilii muscles that cause crow's feet and a glabellar frown line with ageing, cannot be accurately evaluated by surface observation. In 71 subjects, this study investigated the extent to which grimacing muscles are innervated by the bilateral motor cortices, whether the corticofacial projection to the grimacing muscles affects the facially innervated stapedius muscle tone by measuring static compliance of the tympanic membrane, and whether unilateral tight eyelid closure with contraction of the grimacing muscles changes static compliance. Unilateral tight eyelid closure and its subsequent change in the contralateral vertical medial eyebrow position revealed that motor neurons of the orbicularis oculi and corrugator supercilii muscles were innervated by the bilateral motor cortices with weak-to-strong contralateral dominance. The orbicularis oculi, corrugator supercilii, and stapedius muscles innervated by the bilateral motor cortices had increased muscle hyperactivity, which lowered the vertical medial eyebrow position and decreased the static compliance of the tympanic membrane more than those innervated by the unilateral motor cortex. Unilateral enhanced tight eyelid closure with contraction of the grimacing muscles in certain subjects ipsilaterally decreased the static compliance with increased contraction of the stapedius muscle, which probably occurs to immobilise the tympanic membrane and protect the inner ear from loud sound. Evaluation of unilateral tight eyelid closure and the subsequent change in the contralateral vertical medial eyebrow position as well as a measurement of the static compliance for the stapedius muscle tone has revealed muscle hyperactivity of grimacing muscles.

Alterations in protein and amino acid metabolism in rats fed a branched-chain amino acid- or leucine-enriched diet during postprandial and postabsorptive states.

Science.gov (United States)

Holecek, Milan; Siman, Pavel; Vodenicarovova, Melita; Kandar, Roman

2016-01-01

Many people believe in favourable effects of branched-chain amino acids (BCAAs; valine, leucine, and isoleucine), especially leucine, on muscle protein balance and consume BCAAs for many years. We determined the effects of the chronic intake of a BCAA- or leucine-enriched diet on protein and amino acid metabolism in fed and postabsorptive states. Rats were fed a standard diet, a diet with a high content of valine, leucine, and isoleucine (HVLID), or a high content of leucine (HLD) for 2 months. Half of the animals in each group were sacrificed in the fed state on the last day, and the other half were sacrificed after overnight fast. Protein synthesis was assessed using the flooding dose method (L-[3,4,5-(3)H]phenylalanine), proteolysis on the basis of chymotrypsin-like activity (CHTLA) of proteasome and cathepsin B and L activities. Chronic intake of HVLID or HLD enhanced plasma levels of urea, alanine and glutamine. HVLID also increased levels of all three BCAA and branched-chain keto acids (BCKA), HLD increased leucine, ketoisocaproate and alanine aminotransferase and decreased valine, ketovaline, isoleucine, ketoisoleucine, and LDL cholesterol. Tissue weight and protein content were lower in extensor digitorum longus muscles in the HLD group and higher in kidneys in the HVLID and HLD groups. Muscle protein synthesis in postprandial state was higher in the HVLID group, and CHTLA was lower in muscles of the HVLID and HLD groups compared to controls. Overnight starvation enhanced alanine aminotransferase activity in muscles, and decreased protein synthesis in gastrocnemius (in HVLID group) and extensor digitorum longus (in HLD group) muscles more than in controls. Effect of HVLID and HLD on CHTLA in muscles in postabsorptive state was insignificant. The results failed to demonstrate positive effects of the chronic consumption of a BCAA-enriched diet on protein balance in skeletal muscle and indicate rather negative effects from a leucine-enriched diet. The primary

Treadmill Slope Modulates Inflammation, Fiber Type Composition, Androgen, and Glucocorticoid Receptors in the Skeletal Muscle of Overtrained Mice

Directory of Open Access Journals (Sweden)

Alisson L. da Rocha

2017-10-01

Full Text Available Overtraining (OT may be defined as an imbalance between excessive training and adequate recovery period. Recently, a downhill running-based overtraining (OTR/down protocol induced the nonfunctional overreaching state, which is defined as a performance decrement that may be associated with psychological and hormonal disruptions and promoted intramuscular and systemic inflammation. To discriminate the eccentric contraction effects on interleukin 1beta (IL-1β, IL-6, IL-10, IL-15, and SOCS-3, we compared the release of these cytokines in OTR/down with other two OT protocols with the same external load (i.e., the product between training intensity and volume, but performed in uphill (OTR/up and without inclination (OTR. Also, we evaluated the effects of these OT models on the muscle morphology and fiber type composition, serum levels of fatigue markers and corticosterone, as well as androgen receptor (AR and glucocorticoid receptor (GR expressions. For extensor digitorum longus (EDL, OTR/down and OTR groups increased the cytokines and exhibited micro-injuries with polymorphonuclear infiltration. While OTR/down group increased the cytokines in soleus muscle, OTR/up group only increased IL-6. All OT groups presented micro-injuries with polymorphonuclear infiltration. In serum, while OTR/down and OTR/up protocols increased IL-1β, IL-6, and tumor necrosis factor alpha, OTR group increased IL-1β, IL-6, IL-15, and corticosterone. The type II fibers in EDL and soleus, total and phosphorylated AR levels in soleus, and total GR levels in EDL and soleus were differentially modulated by the OT protocols. In summary, the proinflammatory cytokines were more sensitive for OTR/down than for OTR/up and OTR. Also, the specific treadmill inclination of each OT model influenced most of the other evaluated parameters.

Muscle force depends on the amount of transversal muscle loading.

Science.gov (United States)

Siebert, Tobias; Till, Olaf; Stutzig, Norman; Günther, Michael; Blickhan, Reinhard

2014-06-03

Skeletal muscles are embedded in an environment of other muscles, connective tissue, and bones, which may transfer transversal forces to the muscle tissue, thereby compressing it. In a recent study we demonstrated that transversal loading of a muscle with 1.3Ncm(-2) reduces maximum isometric force (Fim) and rate of force development by approximately 5% and 25%, respectively. The aim of the present study was to examine the influence of increasing transversal muscle loading on contraction dynamics. Therefore, we performed isometric experiments on rat M. gastrocnemius medialis (n=9) without and with five different transversal loads corresponding to increasing pressures of 1.3Ncm(-2) to 5.3Ncm(-2) at the contact area between muscle and load. Muscle loading was induced by a custom-made plunger which was able to move in transversal direction. Increasing transversal muscle loading resulted in an almost linear decrease in muscle force from 4.8±1.8% to 12.8±2% Fim. Compared to an unloaded isometric contraction, rate of force development decreased from 20.2±4.0% at 1.3Ncm(-2) muscle loading to 34.6±5.7% at 5.3Ncm(-2). Experimental observation of the impact of transversal muscle loading on contraction dynamics may help to better understand muscle tissue properties. Moreover, applying transversal loads to muscles opens a window to analyze three-dimensional muscle force generation. Data presented in this study may be important to develop and validate muscle models which enable simulation of muscle contractions under compression and enlighten the mechanisms behind. Copyright © 2014 Elsevier Ltd. All rights reserved.

Composition of Muscle Fiber Types in Rat Rotator Cuff Muscles.

Science.gov (United States)

Rui, Yongjun; Pan, Feng; Mi, Jingyi

2016-10-01

The rat is a suitable model to study human rotator cuff pathology owing to the similarities in morphological anatomy structure. However, few studies have reported the composition muscle fiber types of rotator cuff muscles in the rat. In this study, the myosin heavy chain (MyHC) isoforms were stained by immunofluorescence to show the muscle fiber types composition and distribution in rotator cuff muscles of the rat. It was found that rotator cuff muscles in the rat were of mixed fiber type composition. The majority of rotator cuff fibers labeled positively for MyHCII. Moreover, the rat rotator cuff muscles contained hybrid fibers. So, compared with human rotator cuff muscles composed partly of slow-twitch fibers, the majority of fast-twitch fibers in rat rotator cuff muscles should be considered when the rat model study focus on the pathological process of rotator cuff muscles after injury. Gaining greater insight into muscle fiber types in rotator cuff muscles of the rat may contribute to elucidate the mechanism of pathological change in rotator cuff muscles-related diseases. Anat Rec, 299:1397-1401, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Arthroscopic Release of Flexor Hallucis Longus Tendon Sheath in Female Ballet Dancers: Dynamic Pathology, Surgical Technique, and Return to Dancing Performance.

Science.gov (United States)

Funasaki, Hiroki; Hayashi, Hiroteru; Sakamoto, Kanako; Tsuruga, Rei; Marumo, Keishi

2015-12-01

Stenosing tenosynovitis of the flexor hallucis longus (FHL) tendon is known as a major overuse lesion in female dancers. We describe arthroscopic surgical techniques in relation to the dynamic pathology of the disease. Crepitus and pain on moving the great toe with the ankle in plantar flexion on preoperative examination confirm the diagnosis of FHL stenosing tenosynovitis even if the os trigonum is not evident. The ankle is approached through standard posterolateral and posteromedial portals. A 4.0-mm-diameter 30° arthroscope is used. Soft tissues around the talus are cleared with a motorized shaver and a radiofrequency device. The posterior aspects of the talus, os trigonum, and FHL tendon surrounded by the tendon sheath are visualized. The dynamic pathology of the FHL tendon is well observed on passive motion of the great toe. The prominent bone fragment of the talus is removed and the tendon sheath is cut with a retrograde knife and a motorized shaver from the superior border down to the entrance of the fibro-osseous tunnel. Arthroscopic release of the FHL tendon sheath is a useful and easy method to directly approach the dynamic pathology of FHL tenosynovitis in female ballet dancers.

Stretching skeletal muscle: chronic muscle lengthening through sarcomerogenesis.

Directory of Open Access Journals (Sweden)

Alexander M Zöllner

Full Text Available Skeletal muscle responds to passive overstretch through sarcomerogenesis, the creation and serial deposition of new sarcomere units. Sarcomerogenesis is critical to muscle function: It gradually re-positions the muscle back into its optimal operating regime. Animal models of immobilization, limb lengthening, and tendon transfer have provided significant insight into muscle adaptation in vivo. Yet, to date, there is no mathematical model that allows us to predict how skeletal muscle adapts to mechanical stretch in silico. Here we propose a novel mechanistic model for chronic longitudinal muscle growth in response to passive mechanical stretch. We characterize growth through a single scalar-valued internal variable, the serial sarcomere number. Sarcomerogenesis, the evolution of this variable, is driven by the elastic mechanical stretch. To analyze realistic three-dimensional muscle geometries, we embed our model into a nonlinear finite element framework. In a chronic limb lengthening study with a muscle stretch of 1.14, the model predicts an acute sarcomere lengthening from 3.09[Formula: see text]m to 3.51[Formula: see text]m, and a chronic gradual return to the initial sarcomere length within two weeks. Compared to the experiment, the acute model error was 0.00% by design of the model; the chronic model error was 2.13%, which lies within the rage of the experimental standard deviation. Our model explains, from a mechanistic point of view, why gradual multi-step muscle lengthening is less invasive than single-step lengthening. It also explains regional variations in sarcomere length, shorter close to and longer away from the muscle-tendon interface. Once calibrated with a richer data set, our model may help surgeons to prevent muscle overstretch and make informed decisions about optimal stretch increments, stretch timing, and stretch amplitudes. We anticipate our study to open new avenues in orthopedic and reconstructive surgery and enhance

Satellite cell frequency in cross-age transplanted rat extensor digitorum longus muscles

Czech Academy of Sciences Publication Activity Database

Rudež, M.; Carlson, B. M.; Sajko, Š.; Kubínová, Lucie; Wernig, A.; Eržen, I.

2004-01-01

Roč. 14, č. 3 (2004), s. 155-159 ISSN 1120-9992 Grant - others:European programme(XE) QLKG-1999-02034 Institutional research plan: CEZ:AV0Z5011922 Keywords : aging * confocal microscopy * satellite cell s Subject RIV: EA - Cell Biology

Muscle Bioenergetic Considerations for Intrinsic Laryngeal Skeletal Muscle Physiology

Science.gov (United States)

Sandage, Mary J.; Smith, Audrey G.

2017-01-01

Purpose: Intrinsic laryngeal skeletal muscle bioenergetics, the means by which muscles produce fuel for muscle metabolism, is an understudied aspect of laryngeal physiology with direct implications for voice habilitation and rehabilitation. The purpose of this review is to describe bioenergetic pathways identified in limb skeletal muscle and…

Effects of oblique muscle surgery on the rectus muscle pulley

International Nuclear Information System (INIS)

Okanobu, Hirotaka; Kono, Reika; Ohtsuki, Hiroshi

2011-01-01

The purpose of this study was to determine the position of rectus muscle pulleys in Japanese eyes and to evaluate the effect of oblique muscle surgery on rectus muscle pulleys. Quasi-coronal plane MRI was used to determine area centroids of the 4 rectus muscles. The area centroids of the rectus muscles were transformed to 2-dimensional coordinates to represent pulley positions. The effects of oblique muscle surgery on the rectus muscle pulley positions in the coronal plane were evaluated in 10 subjects with cyclovertical strabismus and, as a control, pulley locations in 7 normal Japanese subjects were calculated. The mean positions of the rectus muscle pulleys in the coronal plane did not significantly differ from previous reports on normal populations, including Caucasians. There were significant positional shifts of the individual horizontal and vertical rectus muscle pulleys in 3 (100%) patients with inferior oblique advancement, but not in eyes with inferior oblique recession and superior oblique tendon advancement surgery. The surgical cyclorotatory effect was significantly correlated with the change in the angle of inclination formed by the line connecting the vertical rectus muscles (p=0.0234), but weakly correlated with that of the horizontal rectus muscles. The most important factor that affects the pulley position is the amount of ocular torsion, not the difference in surgical procedure induced by oblique muscle surgery. (author)