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Sample records for carpi ulnaris muscle

  1. Dystrophin deficiency compromises force production of the extensor carpi ulnaris muscle in the canine model of Duchenne muscular dystrophy.

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    Hsiao T Yang

    Full Text Available Loss of muscle force is a salient feature of Duchenne muscular dystrophy (DMD, a fatal disease caused by dystrophin deficiency. Assessment of force production from a single intact muscle has been considered as the gold standard for studying physiological consequences in murine models of DMD. Unfortunately, equivalent assays have not been established in dystrophic dogs. To fill the gap, we developed a novel in situ protocol to measure force generated by the extensor carpi ulnaris (ECU muscle of a dog. We also determined the muscle length to fiber length ratio and the pennation angle of the ECU muscle. Muscle pathology and contractility were compared between normal and affected dogs. Absence of dystrophin resulted in marked histological damage in the ECU muscle of affected dogs. Central nucleation was significantly increased and myofiber size distribution was altered in the dystrophic ECU muscle. Muscle weight and physiological cross sectional area (PCSA showed a trend of reduction in affected dogs although the difference did not reach statistical significance. Force measurement revealed a significant decrease of absolute force, and the PCSA or muscle weight normalized specific forces. To further characterize the physiological defect in affected dog muscle, we conducted eccentric contraction. Dystrophin-null dogs showed a significantly greater force loss following eccentric contraction damage. To our knowledge, this is the first convincing demonstration of force deficit in a single intact muscle in the canine DMD model. The method described here will be of great value to study physiological outcomes following innovative gene and/or cell therapies.

  2. Neglected ruptured flexor carpi ulnaris tendon mimics a soft tissue tumor in the wrist.

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    Rau, Chi-Lun; Yen, Tze-Hsun; Wu, Lien-Chen; Huang, Yi-You; Jaw, Fu-Shan; Liou, Tsan-Hon

    2014-04-01

    A wrist mass is rarely caused by a ruptured tendon in the forearm. The common pathologies are ganglia, tendon tenosynovitis, and giant cell tumors of tendon sheaths. Less common causes are nerve sheath tumors, vascular lesions, or an accessory muscle belly. The authors investigated a case of neglected ruptured flexor carpi ulnaris tendon that mimics a mass in the wrist. To the authors' knowledge, this is the first case report in relevant literature. During investigation, the high-resolution musculoskeletal ultrasound suggested a soft tissue tumor or a ruptured flexor carpi ulnaris tendon. The magnetic resonance imaging scan indicated an accessory flexor carpi ulnaris muscle belly. The diagnosis of ruptured flexor carpi ulnaris tendon was confirmed by surgical exploration. This case indicates that ultrasound may be better suited than magnetic resonance imaging in evaluating a wrist mass for its accuracy, availability, and portability.

  3. Flexor carpi ulnaris tenotomy alone does not eliminate its contribution to wrist torque

    NARCIS (Netherlands)

    de Bruin, Marije; Smeulders, Mark J. C.; Kreulen, Michiel

    2011-01-01

    Flexor carpi ulnaris muscle tenotomy and transfer to the extensor side of the wrist are common procedures used to improve wrist position and dexterity in patients with cerebral palsy. Our aim was to determine whether this muscle still influences wrist torque even after tenotomy of its distal tendon.

  4. [Isolated traumatic dislocation of the extensor carpi ulnaris tendon].

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    Loty, B; Meunier, B; Mazas, F

    1986-01-01

    The authors describe one case of post-traumatic dislocation of the extensor carpi ulnaris tendon. They found eleven other cases reported in the literature. The type of lesion should be looked for in cases of trauma to the wrist without a bony lesion. The treatment should be surgical when function is impaired, either shortly after the initial trauma or if the dislocation becomes habitual. The aim is to reconstruct a tendon sheath. The results were generally satisfactory.

  5. Deoxygenation and the blood volume signals in the flexor carpi ulnaris and radialis muscles obtained during the execution of the Mirallas's test of judo athletes

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    Verdaguer-Codina, Joan; Mirallas, Jaume A.

    1996-12-01

    The technique of execution of any movement in Judo is extremely important. The coaches want tests and tools easy to use and cheaper, to evaluate the progress of a judoist in the tatame. In this paper we present a test developed by Mirallas, which has his name 'Test of Mirallas' to evaluate the maximal power capacity of the judoist. The near infrared spectroscopy (NIRS) signals were obtained to have a measurement of the metabolic work of the flexor carpi ulnaris and radialis muscles, during the execution of the ippon-seoi-nage movement, allowing this measurement to assess by NIRS the maximal oxygen uptake. Also obtained were tympanic, skin forehead, and biceps brachii temperatures during the test time and recovery phase to study the effects of ambient conditions and the post-exercise oxygen consumption. The deoxygenation and blood volume signals obtained gave different results, demonstrating the hypothesis of the coaches that some judoist do the execution of the ippon-seoi-nage movement correctly and the rest didn't. The heart rate frequency obtained in the group of judoist was between 190-207 bpm, and in the minute five of post-exercise was 114-137 bpm; the time employed in the MIrallas's test were from 7 feet 14 inches to 13 feet 49 inches, and the total of movements were from 199 to 409. The data obtained in the skin forehead, and skin biceps brachii confirms previous works that the oxygen consumption remains after exercise in the muscle studied. According to the results, the test developed by Mirallas is a good tool to evaluate the performance of judoist any time, giving better results compared with standard tests.

  6. Ulnar-sided pain due to extensor carpi ulnaris tendon subluxation: a case report

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    Cift Hakan

    2012-11-01

    Full Text Available Abstract Introduction We present the case of a patient with extensor carpi ulnaris tendon subluxation who was first treated for distal radioulnar joint sprain. Case presentation A 25-year-old Caucasian man was seen at our policlinic one month after he had fallen on his outstretched hand. A diagnosis of extensor carpi ulnaris subluxation was made clinically but we also had the magnetic resonance imaging scan of the patient’s wrist which displayed an increased signal on T2-weighted images consistent with inflammation around the extensor carpi ulnaris tendon. The extensor carpi ulnaris tendon was found to be dislocating during supination and relocating during pronation. The sheath was reconstructed using extensor retinaculum due to attenuation of subsheath. Conclusion There was no recurrent dislocation of the extensor carpi ulnaris tendon of the patient at his last follow up 12 months after the operation.

  7. Progressive surgical dissection for tendon transposition affects length-force characteristics of rat flexor carpi ulnaris muscle

    NARCIS (Netherlands)

    Smeulders, Mark J.C.; Kreulen, Michiel; Hage, J. Joris; Baan, Guus C.; Huijing, P.A.J.B.M.

    2002-01-01

    Extramuscular connective tissue and muscular fascia have been suggested to form a myo-fascial pathway for transmission of forces over a joint that is additional to the generally accepted myo-tendinous pathway. The consequences of myo-fascial force transmission for the outcome of conventional muscle

  8. Association between distal ulnar morphology and extensor carpi ulnaris tendon pathology

    International Nuclear Information System (INIS)

    Chang, Connie Y.; Huang, Ambrose J.; Bredella, Miriam A.; Kattapuram, Susan V.; Torriani, Martin

    2014-01-01

    The purpose of this study was to evaluate the association between distal ulnar morphology and extensor carpi ulnaris (ECU) tendon pathology. We retrospectively reviewed 71 adult wrist MRI studies with ECU tendon pathology (tenosynovitis, tendinopathy, or tear), and/or ECU subluxation. Subjects did not have a history of trauma, surgery, infection, or inflammatory arthritis. MRI studies from 46 subjects without ECU tendon pathology or subluxation were used as controls. The following morphological parameters of the distal ulna were measured independently by two readers: ulnar variance relative to radius, ulnar styloid process length, ECU groove depth and length. Subjects and controls were compared using Student's t test. Inter-observer agreement (ICC) was calculated. There was a significant correlation between negative ulnar variance and ECU tendon pathology (reader 1 [R1], P = 0.01; reader 2 [R2], P 0.64 for all parameters. Distal ulnar morphology may be associated with ECU tendon abnormalities. (orig.)

  9. The extensor carpi ulnaris pseudolesion: evaluation with microCT, histology, and MRI

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    Ali, Sayed; Cunningham, Ryan; Mohamed, Feroze; Amin, Mamta; Popoff, Steven N.; Barbe, Mary F.

    2015-01-01

    To determine if magic angle plays a role in apparent central increased signal intensity of the distal extensor carpi ulnaris tendon (ECU) on MRI, to see if histologic findings of tendon degeneration are associated with increased T1 or T2 tendon signal on MR imaging, and to determine the prevalence of the ECU ''pseudolesion''. A standard 3 Tesla protocol was utilized to scan ten cadaveric wrists. A 40 mm length of 10 ECU and four extensor carpi radialis brevis (ECRB) tendons were immersion fixed before microCT scanning. Staining with Alcian blue, Masson's trichrome and Safranin O was performed before light microscopy. Fifty clinical wrist MRIs were also reviewed for the presence of increased T1 and/or T2 signal. Central increased T1 and/or T2 signal was observed in 9 of 10 cadaveric ECU tendons, but not in ECRB tendons. MicroCT and histology showed inter-tendinous matrix between the two distal heads of the ECU. Increased mucoid degeneration correlated with increased MRI signal intensity. The tendon fibers were at a maximum of 8.39 to the longitudinal axis on microCT. Clinical MRIs showed increased T1 signal in 6 %, increased T2 signal in 8 %, increased T1 and T2 signal in 80 %, and 6 % showing no increased signal. Central increased T1 and/or T2 signal in the ECU tendon indicates the presence of normal inter-tendinous ground substance, with increased proteoglycan content (mucoid degeneration) responsible for increased signal intensity. None of the fibers were shown on microCT to approach the magic angle. (orig.)

  10. The extensor carpi ulnaris pseudolesion: evaluation with microCT, histology, and MRI

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    Ali, Sayed; Cunningham, Ryan; Mohamed, Feroze [Temple University Hospital, Department of Radiology, Philadelphia, PA (United States); Amin, Mamta; Popoff, Steven N.; Barbe, Mary F. [Temple University School of Medicine, Department of Anatomy, Philadelphia, PA (United States)

    2015-12-15

    To determine if magic angle plays a role in apparent central increased signal intensity of the distal extensor carpi ulnaris tendon (ECU) on MRI, to see if histologic findings of tendon degeneration are associated with increased T1 or T2 tendon signal on MR imaging, and to determine the prevalence of the ECU ''pseudolesion''. A standard 3 Tesla protocol was utilized to scan ten cadaveric wrists. A 40 mm length of 10 ECU and four extensor carpi radialis brevis (ECRB) tendons were immersion fixed before microCT scanning. Staining with Alcian blue, Masson's trichrome and Safranin O was performed before light microscopy. Fifty clinical wrist MRIs were also reviewed for the presence of increased T1 and/or T2 signal. Central increased T1 and/or T2 signal was observed in 9 of 10 cadaveric ECU tendons, but not in ECRB tendons. MicroCT and histology showed inter-tendinous matrix between the two distal heads of the ECU. Increased mucoid degeneration correlated with increased MRI signal intensity. The tendon fibers were at a maximum of 8.39 to the longitudinal axis on microCT. Clinical MRIs showed increased T1 signal in 6 %, increased T2 signal in 8 %, increased T1 and T2 signal in 80 %, and 6 % showing no increased signal. Central increased T1 and/or T2 signal in the ECU tendon indicates the presence of normal inter-tendinous ground substance, with increased proteoglycan content (mucoid degeneration) responsible for increased signal intensity. None of the fibers were shown on microCT to approach the magic angle. (orig.)

  11. Enthesiopathy of the flexor carpi ulnaris at the pisiform: Findings of high-frequency sonography

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    Wick, Marius C.; Weiss, Ruediger J.; Arora, Rohit; Gabl, Markus; Gruber, Johann; Jaschke, Werner; Klauser, Andrea S.

    2011-01-01

    Objectives: Acute or chronic pain at the pisiform may be due to tendinopathy of the flexor carpi ulnaris tendon (FCU) insertion, mechanical overuse, bony fractures, and osteoarthritis of the pisiform-triquetral joint. Enthesiopathy of the FCU at the pisiform might exhibit abnormalities assessable for sonographic characterization. This study aimed to determine the most relevant sonographic features of tendinopathy of the FCU insertion at the pisiform. Materials and methods: We retrospectively analyzed radiological findings of 9 patients admitted for high-frequency sonographic evaluation of a painful pisiform FCU insertion. The FCU insertion was assessed for active enthesiopathy in terms of tendon thickening and hyperemia, peritendinous effusion, peritendinous hyperemia, peritendinous soft tissue thickening, cystic fluid collections, erosive cortical irregularities, and osteoproliferative alterations at the pisiform. Results: Of all patients, 5 had inflammatory rheumatic disorders and the remainder had a painful pisiform FCU insertion related to overuse. While peritendinous effusion, pisiform erosive cortical irregularities, and peritendinous soft tissue thickening at the FCU insertion were exclusively found in rheumatic patients, active enthesiopathy of the FCU tendon, pisiform osteoproliferative alterations, and hyperemia of the peritendinous soft tissue were inconsistent and found in both groups. Cystic fluid collections from the pisiform-triquetral joint were only seen in patients with overuse. Conclusions: In this small case series of patients with pain at the pisiform FCU insertion, we could reveal several typical sonographic features for insertion tendinopathy. Further studies should prove if these sonographic features could impact on the management of patients with pain at the pisiform.

  12. Enthesiopathy of the flexor carpi ulnaris at the pisiform: Findings of high-frequency sonography

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    Wick, Marius C., E-mail: marius.wick@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria); Weiss, Ruediger J., E-mail: rudiger.weiss@karolinska.se [Department of Molecular Medicine and Surgery, Section of Orthopaedics and Sports Medicine, Karolinska University Hospital (Solna), Karolinska Institutet, S-17176 Stockholm (Sweden); Arora, Rohit, E-mail: rohit.arora@uki.at [Department for Trauma Surgery and Sports Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria); Gabl, Markus, E-mail: markus.gabl@uki.at [Department for Trauma Surgery and Sports Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria); Gruber, Johann, E-mail: johann.gruber@uki.at [Department of Internal Medicine I, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria); Jaschke, Werner, E-mail: werner.jaschke@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria); Klauser, Andrea S., E-mail: andrea.klauser@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria)

    2011-02-15

    Objectives: Acute or chronic pain at the pisiform may be due to tendinopathy of the flexor carpi ulnaris tendon (FCU) insertion, mechanical overuse, bony fractures, and osteoarthritis of the pisiform-triquetral joint. Enthesiopathy of the FCU at the pisiform might exhibit abnormalities assessable for sonographic characterization. This study aimed to determine the most relevant sonographic features of tendinopathy of the FCU insertion at the pisiform. Materials and methods: We retrospectively analyzed radiological findings of 9 patients admitted for high-frequency sonographic evaluation of a painful pisiform FCU insertion. The FCU insertion was assessed for active enthesiopathy in terms of tendon thickening and hyperemia, peritendinous effusion, peritendinous hyperemia, peritendinous soft tissue thickening, cystic fluid collections, erosive cortical irregularities, and osteoproliferative alterations at the pisiform. Results: Of all patients, 5 had inflammatory rheumatic disorders and the remainder had a painful pisiform FCU insertion related to overuse. While peritendinous effusion, pisiform erosive cortical irregularities, and peritendinous soft tissue thickening at the FCU insertion were exclusively found in rheumatic patients, active enthesiopathy of the FCU tendon, pisiform osteoproliferative alterations, and hyperemia of the peritendinous soft tissue were inconsistent and found in both groups. Cystic fluid collections from the pisiform-triquetral joint were only seen in patients with overuse. Conclusions: In this small case series of patients with pain at the pisiform FCU insertion, we could reveal several typical sonographic features for insertion tendinopathy. Further studies should prove if these sonographic features could impact on the management of patients with pain at the pisiform.

  13. A RARE CASE OF BILATERAL FLEXOR CARPI ULNARIS VARIATION: ANATOMICAL AND CLINICAL CONSIDERATIONS AND LITERATURE REVIEW. Un caso raro de variación bilateral del músculo flexor carpi ulnaris-significado anatómico y clínico y revisión literaria

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    Alexandar Iliev

    2016-07-01

    Full Text Available Various aberrant muscles and fibro-tendinous structures have been identified in the anterior wrist, some of them blamed to be possible causes for neurovascular compression syndromes. Herewith, we describe such an intriguing structure related to the flexor carpi ulnaris muscle. During routine dissection of both upper limbs of an adult cadaver, an interesting crescent-shaped fibro-tendinous structure was identified bilaterally, arising broadly from the lateral side of the distal tendon of the flexor carpi ulnaris. This aberrant structure arched over the ulnar artery and nerve before they enter the canal of Guyon and the median nerve just before the carpal tunnel. Further distally, the fibro-tendinous arch narrowed and interlaced with the flexor retinaculum and palmar aponeurosis longitudinal fibres. In this case there was also concomitant bilateral absence of the palmaris longus muscle. Because this aberrant fibro-tendinous arch has very close relations to the median nerve and ulnar nerve and artery in the wrist, it may possibly cause neurovascular compression during some muscle activity.Varios músculos y estructuras fibro-tendinosas aberrantes se han identificado en la parte anterior de la muñeca, muchas de las cuales se considera que pueden causar síndromes de compresión neurovascular. A continuación describimos una tal estructura relacionada con el músculo flexor carpi ulnaris. Durante disecciones de rutina de ambos miembros superiores de cadáveres de adultos fue descubierta una estructura fibro-tendinosa con forma de medialuna en ambos miembros originando de la parte lateral del tendón distal del flexor carpi ulnaris. Esta estructura formaba un arco pasando sobre y cubriendo la arteria y el nervio ulnar antes de que entren en el canal de Guyon, y sobre el nervio mediano justo antes de que entre en el canal carpal. Este arco fibro-tendinoso seguía estrechándose hasta entrelazarse con el ligamento transverso del carpo y las fibras

  14. Association between distal ulnar morphology and extensor carpi ulnaris tendon pathology

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    Chang, Connie Y.; Huang, Ambrose J.; Bredella, Miriam A.; Kattapuram, Susan V.; Torriani, Martin [General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Massachusetts, Boston, MA (United States)

    2014-06-15

    The purpose of this study was to evaluate the association between distal ulnar morphology and extensor carpi ulnaris (ECU) tendon pathology. We retrospectively reviewed 71 adult wrist MRI studies with ECU tendon pathology (tenosynovitis, tendinopathy, or tear), and/or ECU subluxation. Subjects did not have a history of trauma, surgery, infection, or inflammatory arthritis. MRI studies from 46 subjects without ECU tendon pathology or subluxation were used as controls. The following morphological parameters of the distal ulna were measured independently by two readers: ulnar variance relative to radius, ulnar styloid process length, ECU groove depth and length. Subjects and controls were compared using Student's t test. Inter-observer agreement (ICC) was calculated. There was a significant correlation between negative ulnar variance and ECU tendon pathology (reader 1 [R1], P = 0.01; reader 2 [R2], P < 0.0001; R1 and R2 averaged data, P < 0.0001) and ECU tendon subluxation (P = 0.001; P = 0.0001; P < 0.0001). In subjects with ECU tendon subluxation there was also a trend toward a shorter length (P = 0.3; P <0.0001; P = 0.001) and a shallower ECU groove (P = 0.01; P = 0.03; P = 0.01; R1 and R2 averaged data with Bonferroni correction, P = 0.08). ECU groove depth (P = 0.6; P = 0.8; P = 0.9) and groove length (P = 0.1; P = 0.4; P = 0.7) showed no significant correlation with ECU tendon pathology, and length of the ulnar styloid process showed no significant correlation with ECU tendon pathology (P = 0.2; P = 0.3; P = 0.2) or subluxation (P = 0.4; P = 0.5; P = 0.5). Inter-observer agreement (ICC) was >0.64 for all parameters. Distal ulnar morphology may be associated with ECU tendon abnormalities. (orig.)

  15. A Case Report of Traumatic Partial Extensor Carpi Ulnaris Subluxation in an Elite Hockey Player With Review of the Literature.

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    Aoude, Ahmed; Van Lancker, Hans; Chari, Basavaraj; Boily, Mathieu; Martineau, Paul A

    2017-07-01

    In this article, we present a unique case of traumatic partial recurrent extensor carpi ulnaris (ECU) subluxation in an elite hockey player. To the best of our knowledge, this is the only report of partial ECU subluxation due to a split in the ECU tendon presented in the literature. This case illustrates the importance of proper diagnosis and treatment of such a lesion. We also emphasize that dynamic ultrasound is an excellent and cost-effective imaging modality that can help with the diagnosis of partial ECU subluxation. Finally, surgical treatment for failed conservative management showed excellent results in an elite athlete.

  16. Subluxation of the Extensor Carpi Ulnaris Tendon Associated with the Extensor Digitorum Tendon Subluxation of the Long Finger

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    Kim, Byung-Sung; Yoon, Hong-Gi; Kim, Hyung-Tae; Park, Kang-Hee; Kim, Chang-Geun

    2013-01-01

    A twenty-year-old male visited our clinic with wrist and long finger metacarpophalangeal (MP) joint pain. Dynamic ultrasonography revealed sagittal band (SB) ulnar subluxation and extensor carpi ulnaris (ECU) volar subluxation. Magnetic resonance imaging showed longitudinal splitting and dislocation of the volar half slip of the ECU tendon. The redundant radial SB was augmented and ECU sheath was advanced to the periosteum using suture anchors. He was able to perform his previous activities at the last follow-up. We encountered a case of "simulateous" ECU dislocation with extensor tendon subluxation of the long finger at the MP joint. Therefore, we report this case with a review of the relevant literature. PMID:23467477

  17. Transfer of extensor digiti minimi and extensor carpi ulnaris nerve branches to the intrinsic motor nerve branches: A histological study on cadaver.

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    Namazi, H; Haji Vandi, S

    2017-06-01

    In cases of high ulnar and median nerve palsy, result of nerve repair in term of intrinsic muscle recovery is unsatisfactory. Distal nerve transfer can alleviate the regeneration time and improve the results. Transfer of the extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU) nerve branches to the deep branch of ulnar nerve (DBUN)/recurrent branch of median nerve (RMN) at wrist had been used to restore intrinsic hand function but, incomplete recovery occurred. The axon count at the donor nerve has a strong influence on the final results. This cadaveric study aims to analyses the histology of this nerve transfer to evaluate whether these donor nerves are suitable for this transfer or another donor nerve may be considered. Ten cadaveric upper limbs dissected to identify the location of the EDM, ECU, RMN and DBUN. Surface area, fascicle count, and axon number was determined by histological methods. The mean of axon number in the EDM, ECU, RMN and DBUN branches was 5931, 7355, 30960 and 35426, respectively. In this study, the number of axons in the EDM and ECU branches was 37% (13281/35426) of that in the DBUN. Also, the number of axons in the EDM and ECU branches was 42% (13281/30960) of that in the RMN. The axon count data showed an unfavorable match between the EDM, ECU and DBUN/RMN. Therefore, it is suggested that another donor nerve with higher axon number to be considered. Cadaver study (histological study). Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Athletic injuries of the extensor carpi ulnaris subsheath: MRI findings and utility of gadolinium-enhanced fat-saturated T1-weighted sequences with wrist pronation and supination

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    Jeantroux, Jeremy; Guerini, Henri; Drape, Jean-Luc [Universite Paris Descartes, Department of Radiology B, Hopital Cochin, AP-HP, Paris (France); Becce, Fabio [Universite Paris Descartes, Department of Radiology B, Hopital Cochin, AP-HP, Paris (France); University of Lausanne, Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Montalvan, Bernard [French Tennis Federation, Paris (France); Viet, Dominique Le [Hand Institute, Clinique Jouvenet, Paris (France)

    2011-01-15

    To report the magnetic resonance imaging (MRI) findings in athletic injuries of the extensor carpi ulnaris (ECU) subsheath, assessing the utility of gadolinium-enhanced (Gd) fat-saturated (FS) T1-weighted sequences with wrist pronation and supination. Sixteen patients (13 male, three female; mean age 30.3 years) with athletic injuries of the ECU subsheath sustained between January 2003 and June 2009 were included in this retrospective study. Initial and follow-up 1.5-T wrist MRIs were performed with transverse T1-weighted and STIR sequences in pronation, and Gd FS T1-weighted sequences with wrist pronation and supination. Two radiologists assessed the type of injury (A to C), ECU tendon stability, associated lesions and rated pulse sequences using a three-point scale: 1 = poor, 2 = good and 3 = excellent. Gd-enhanced FS T1-weighted transverse sequences in supination (2.63) and pronation (2.56) were most valuable, compared with STIR (2.19) and T1-weighted (1.94). Nine type A, one type B and six type C injuries were found. There were trends towards diminution in size, signal intensity and enhancement of associated pouches on follow-up MRI and tendon stabilisation within the ulnar groove. Gd-enhanced FS T1-weighted sequences with wrist pronation and supination are most valuable in assessing and follow-up athletic injuries of the ECU subsheath on 1.5-T MRI. (orig.)

  19. Diagnostic Performance of the Extensor Carpi Ulnaris (ECU) Synergy Test to Detect Sonographic ECU Abnormalities in Chronic Dorsal Ulnar-Sided Wrist Pain.

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    Sato, Junko; Ishii, Yoshinori; Noguchi, Hideo

    2016-01-01

    The extensor carpi ulnaris (ECU) tendon synergy test is a simple and unique diagnostic maneuver for evaluation of chronic dorsal ulnar-sided wrist pain, which applies isolated tension to the ECU without greatly stressing other structures. This study aimed to investigate the diagnostic performance of the ECU synergy test to detect ECU abnormalities on sonography. Forty affected wrists from 39 consecutive patients with chronic dorsal ulnar-sided wrist pain that continued for greater than 1 month were examined with the ECU synergy test and sonography. The sensitivity, specificity, positive predictive value, and negative predictive value of the ECU synergy test to detect ECU abnormalities were evaluated. We compared the results of the ECU synergy test between groups with and without ECU abnormalities and also compared the ages, sexes, and symptomatic durations of the patients between groups with positive and negative ECU synergy test results and between the groups with and without ECU abnormalities. The sensitivity, specificity, positive predictive value, and negative predictive value were 73.7%, 85.7%, 82.4%, and 78.3%, respectively. There was significant difference in the ECU synergy test results between the groups with and without ECU abnormalities (P synergy test could be a useful provocative maneuver to detect ECU abnormalities in patients with chronic dorsal ulnar-sided wrist pain. © 2016 by the American Institute of Ultrasound in Medicine.

  20. Role of muscles in the stabilization of ligament-deficient wrists.

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    Esplugas, Mireia; Garcia-Elias, Marc; Lluch, Alex; Llusá Pérez, Manuel

    2016-01-01

    This article reviews the results of a series of cadaver investigations aimed at clarifying the role of muscles in the stabilization of ligament-deficient wrists. According to these studies, isometric contraction of some forearm muscles induces midcarpal (MC) supination (ie, the abductor pollicis longus, extensor carpi radialis longus, and flexor carpi ulnaris), whereas other muscles induce MC pronation (ie, the extensor carpi ulnaris). Because MC supination implies tightening of the volar scaphoid-distal row ligaments, the MC supination muscles are likely to prevent scaphoid collapse of wrists with scapholunate ligament insufficiency. MC pronator muscles, by contrast, would be beneficial in stabilizing wrists with ulnar-sided ligament deficiencies owing to their ability to tighten the triquetrum-distal row ligaments. Should these laboratory findings be validated by additional clinical research, proprioceptive reeducation of selected muscles could become an important tool for the treatment of dynamic carpal instabilities. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

  1. 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

  2. The effects of Kinesio Taping on the trajectory of the forelimb and the muscle activity of the Musculus brachiocephalicus and the Musculus extensor carpi radialis in horses.

    Directory of Open Access Journals (Sweden)

    Antonia Zellner

    Full Text Available The present study aimed to investigate the effects of Kinesio Taping on the trajectory of the forelimb and the muscle activity of the M. brachiocephalicus and the M. extensor carpi radialis in horses. 19 horses and ponies of different breeds (body weight: 496±117 kg, gender (8 mares, 10 geldings and 3 stallions and ages (14.9±6.9 years old were analysed without Kinesio Tape ("no tape", with Kinesio Tape (muscle facilitation application on both muscles of both sides, "with tape" and immediately after Kinesio Taping ("post tape" through kinematic motion analysis and surface electromyography on a treadmill at the walk (speed: 1.5±0.1 m/s and trot (speed: 3.1±0.3 m/s.The results of the surface electromyography (maximum muscle activity at the walk and trot and the kinematic motion analysis (maximum stride length and maximum height of the forelimbs flight arc at the walk and trot showed that there were no significant differences between "no tape", "with tape" and "post tape".To sum up, Kinesio Taping on the M. brachiocephalicus and the M. extensor carpi radialis does not affect (in a positive or negative manner the trajectory of the forelimb or the muscle activity of the M. brachiocephalicus and the M. extensor carpi radialis in horses.

  3. The effects of Kinesio Taping on the trajectory of the forelimb and the muscle activity of the Musculus brachiocephalicus and the Musculus extensor carpi radialis in horses.

    Science.gov (United States)

    Zellner, Antonia; Bockstahler, Barbara; Peham, Christian

    2017-01-01

    The present study aimed to investigate the effects of Kinesio Taping on the trajectory of the forelimb and the muscle activity of the M. brachiocephalicus and the M. extensor carpi radialis in horses. 19 horses and ponies of different breeds (body weight: 496±117 kg), gender (8 mares, 10 geldings and 3 stallions) and ages (14.9±6.9 years old) were analysed without Kinesio Tape ("no tape"), with Kinesio Tape (muscle facilitation application on both muscles of both sides, "with tape") and immediately after Kinesio Taping ("post tape") through kinematic motion analysis and surface electromyography on a treadmill at the walk (speed: 1.5±0.1 m/s) and trot (speed: 3.1±0.3 m/s). The results of the surface electromyography (maximum muscle activity at the walk and trot) and the kinematic motion analysis (maximum stride length and maximum height of the forelimbs flight arc at the walk and trot) showed that there were no significant differences between "no tape", "with tape" and "post tape". To sum up, Kinesio Taping on the M. brachiocephalicus and the M. extensor carpi radialis does not affect (in a positive or negative manner) the trajectory of the forelimb or the muscle activity of the M. brachiocephalicus and the M. extensor carpi radialis in horses.

  4. Operator performance and localized muscle fatigue in a simulated space vehicle control task

    Science.gov (United States)

    Lewis, J. L., Jr.

    1979-01-01

    Fourier transforms in a special purpose computer were utilized to obtain power spectral density functions from electromyograms of the biceps brachii, triceps brachii, brachioradialis, flexor carpi ulnaris, brachialis, and pronator teres in eight subjects performing isometric tracking tasks in two directions utilizing a prototype spacecraft rotational hand controller. Analysis of these spectra in general purpose computers aided in defining muscles involved in performing the task, and yielded a derived measure potentially useful in predicting task termination. The triceps was the only muscle to show significant differences in all possible tests for simple effects in both tasks and, overall, was the most consistently involved of the six muscles. The total power monitored for triceps, biceps, and brachialis dropped to minimal levels across all subjects earlier than for other muscles. However, smaller variances existed for the biceps, brachioradialis, brachialis, and flexor carpi ulnaris muscles and could provide longer predictive times due to smaller standard deviations for a greater population range.

  5. Comparison of EMG during passive stretching and shortening phases of each muscle for the investigation of parkinsonian rigidity.

    Science.gov (United States)

    Kwon, Yuri; Kim, Ji-Won; Kim, Ji-Sun; Koh, Seong-Beom; Eom, Gwang-Moon; Lim, Tae-Hong

    2015-01-01

    The aim of this study was to test the hypothesis in the literature that torque resistance of parkinsonian rigidity is the difference between the independent contributions of stretched and shortened muscles. The hypothesis was tested using muscle-specific stretch-shortening (MSSS) EMG ratio in this study. Nineteen patients with idiopathic Parkinson's disease (PD) and 18 healthy subjects (the mean age comparable to that of patients) participated in this study. The EMG activity was measured in the four muscles involved in wrist joint movement, i.e. flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis and extensor carpi ulnaris. The passive flexion-extension movement with a range of ±30∘ was applied at wrist joint. Root mean squared (RMS) mean was calculated from the envelope of the EMG for each of stretching and shortening phases. MSSS EMG ratio was defined as the ratio of RMS EMG of stretching phase and RMS EMG of shortening phase of a single muscle, and it was calculated for each muscle. MSSS EMG ratios were smaller than one in all muscles. These results indicate that all wrist muscles generate greater mean EMG during shortening than during stretching. Therefore, the torque resistance of parkinsonian rigidity cannot be explained as the simple summation of independent antagonistic torque pair.

  6. Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles.

    Science.gov (United States)

    Liu, An-Tang; Liu, Ben-Li; Lu, Li-Xuan; Chen, Gang; Yu, Da-Zhi; Zhu, Lie; Guo, Rong; Dang, Rui-Shan; Jiang, Hua

    2014-07-01

    The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm(2)), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm(2)). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18-0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the 'design' of their

  7. 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.

  8. Dorsal forearm muscles: US anatomy Pictorial Essay

    Science.gov (United States)

    Precerutti, M.; Garioni, E.; Ferrozzi, G.

    2010-01-01

    The dorsal compartment of the forearm contains nine muscles: four belong to the superficial group (extensor digitorum communis, extensor digiti minimi, extensor carpi ulnaris and anconeus) and five to the deep group (supinator, abductor longus, extensor pollicis brevis, extensor pollicis longus, and extensor indices). Of these nine muscles the following details are considered: origin, course, distal insertion and their anatomical connection with those structures which are most often affected by pathologies. The radiologist must have a thorough knowledge of this complex topographic anatomy in order to perform ultrasound (US) and magnetic resonance imaging (MRI) examinations and correctly interpret the images. PMID:23396199

  9. Changes in Systolic Blood Pressure during Isometric Contractions of Different Size Muscle Groups.

    Science.gov (United States)

    1979-05-01

    extensor carpi radialis, flexor digitorum sublimis, and the flexor digitorum profundus. There was no electromyograp ic evidence of activity from the...stabilizers of tais activity are the flexor digitorium I superficialis and profundus, extensor carpi radialis, opponens pollicis, flexor pollicis longus and...radialis) , wrist extensors ( extensor carpi ulnaris) , and the biceps and triceps during index finger adductior. and the biceps, triceps, anterior

  10. Muscle coordination and force variability during static and dynamic tracking tasks.

    Science.gov (United States)

    Svendsen, Jacob H; Samani, Afshin; Mayntzhusen, Klaus; Madeleine, Pascal

    2011-12-01

    This study examined muscular activity patterns of extensor and flexor muscles and variability of forces during static and dynamic tracking tasks using compensatory and pursuit display. Fourteen volunteers performed isometric actions in two conditions: (i) a static tracking task consisting of flexion/pronation, ulnar deviation, extension/supination and radial deviation of the wrist at 20% maximum voluntary contraction (MVC), and (ii) a dynamic tracking task aiming at following a moving target at 20% MVC in the four directions of contraction. Surface electromyography (SEMG) from extensor carpi ulnaris, extensor carpi radialis, flexor carpi ulnaris and flexor digitorum superficialis muscles and exerted forces in the transverse and sagittal plane were recorded. Normalized root mean square and mutual information (index of functional connectivity within muscles) of SEMGs and the standard deviation and sample entropy of force signals were extracted. Larger SEMG amplitudes were found for the dynamic task (pstatic task (pforce) concomitant with smaller sample entropy was observed for the dynamic task compared with the static task (pforce variability relying on feedback and feed-forward control strategies in relation to display modes during static and dynamic tracking tasks. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Effects of tendon and muscle belly dissection on muscular force transmission following tendon transfer in the rat

    NARCIS (Netherlands)

    Maas, H.; Huijing, P.A.J.B.M.

    2012-01-01

    The aim of the present study was to quantify to what extent the scar tissue formation following the transfer of flexor carpi ulnaris (FCU) to the distal tendon of extensor carpi radialis (ECR) affects the force transmission from transferred FCU in the rat. Five weeks after recovery from surgery

  12. Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures.

    Science.gov (United States)

    Islam, Md Anamul; Sundaraj, Kenneth; Ahmad, R Badlishah; Sundaraj, Sebastian; Ahamed, Nizam Uddin; Ali, Md Asraf

    2014-01-01

    In mechanomyography (MMG), crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity. The aim of the present study was two-fold: i) to quantify the level of crosstalk in the mechanomyographic (MMG) signals from the longitudinal (Lo), lateral (La) and transverse (Tr) axes of the extensor digitorum (ED), extensor carpi ulnaris (ECU) and flexor carpi ulnaris (FCU) muscles during isometric wrist flexion (WF) and extension (WE), radial (RD) and ulnar (UD) deviations; and ii) to analyze whether the three-directional MMG signals influence the level of crosstalk between the muscle groups during these wrist postures. Twenty, healthy right-handed men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg) participated in this study. During each wrist posture, the MMG signals propagated through the axes of the muscles were detected using three separate tri-axial accelerometers. The x-axis, y-axis, and z-axis of the sensor were placed in the Lo, La, and Tr directions with respect to muscle fibers. The peak cross-correlations were used to quantify the proportion of crosstalk between the different muscle groups. The average level of crosstalk in the MMG signals generated by the muscle groups ranged from: 34.28-69.69% for the Lo axis, 27.32-52.55% for the La axis and 11.38-25.55% for the Tr axis for all participants and their wrist postures. The Tr axes between the muscle groups showed significantly smaller crosstalk values for all wrist postures [F (2, 38) = 14-63, pmovement research, especially for the examination of muscle mechanics during various types of the wrist postures.

  13. OnabotulinumtoxinA muscle injection patterns in adult spasticity: a systematic literature review

    Science.gov (United States)

    2013-01-01

    Background OnabotulinumtoxinA has demonstrated significant benefit in adult focal spasticity. This study reviews the injection patterns (i.e., muscle distribution, dosing) of onabotulinumtoxinA for treatment of adult spasticity, as reported in published studies. Methods A systematic review of clinical trials and observational studies published between 1990 and 2011 reporting data on muscles injected with onabotulinumtoxinA in adult patients treated for any cause of spasticity. Results 28 randomized, 5 nonrandomized, and 37 single-arm studies evaluating 2,163 adult patients were included. The most frequently injected upper-limb muscles were flexor carpi radialis (64.0% of patients), flexor carpi ulnaris (59.1%), flexor digitorum superficialis (57.2%), flexor digitorum profundus (52.5%), and biceps brachii (38.8%). The most frequently injected lower-limb muscles were the gastrocnemius (66.1% of patients), soleus (54.7%), and tibialis posterior (50.5%). The overall dose range reported was 5–200 U for upper-limb muscles and 10–400 U for lower-limb muscles. Conclusions The reviewed evidence indicates that the muscles most frequently injected with onabotulinumtoxinA in adults with spasticity were the wrist, elbow, and finger flexors and the ankle plantar flexors. OnabotulinumtoxinA was injected over a broad range of doses per muscle among the studies included in this review, but individual practitioners should be mindful of local regulatory approvals and regulations. PMID:24011236

  14. Characterization of focal muscle compression under impact loading

    Science.gov (United States)

    Butler, B. J.; Sory, D. R.; Nguyen, T.-T. N.; Proud, W. G.; Williams, A.; Brown, K. A.

    2017-01-01

    In modern wars over 70% of combat wounds are to the extremities. These injuries are characterized by disruption and contamination of the limb soft tissue envelope. The extent of this tissue trauma and contamination determine the outcome of the extremity injury. In military injury, common post-traumatic complications at amputation sites include heterotopic ossification (formation of bone in soft tissue), and severe soft tissue and bone infections. We are currently developing a model of soft tissue injury that recreates pathologies observed in combat injuries. Here we present characterization of a controlled focal compression of the rabbit flexor carpi ulnaris (FCU) muscle group. The FCU was previously identified as a suitable site for studying impact injury because its muscle belly can easily be mobilized from the underlying bone without disturbing anatomical alignment in the limb. We show how macroscopic changes in tissue organization, as visualized using optical microscopy, can be correlated with data from temporally resolved traces of loading conditions.

  15. Warm-up with weighted bat and adjustment of upper limb muscle activity in bat swinging under movement correction conditions.

    Science.gov (United States)

    Ohta, Yoichi; Ishii, Yasumitsu; Ikudome, Sachi; Nakamoto, Hiroki

    2014-02-01

    The effects of weighted bat warm-up on adjustment of upper limb muscle activity were investigated during baseball bat swinging under dynamic conditions that require a spatial and temporal adjustment of the swinging to hit a moving target. Seven male college baseball players participated in this study. Using a batting simulator, the task was to swing the standard bat coincident with the arrival timing and position of a moving target after three warm-up swings using a standard or weighted bat. There was no significant effect of weighted bat warm-up on muscle activity before impact associated with temporal or spatial movement corrections. However, lower inhibition of the extensor carpi ulnaris muscle activity was observed in a velocity-changed condition in the weighted bat warm-up, as compared to a standard bat warm-up. It is suggested that weighted bat warm-up decreases the adjustment ability associated with inhibition of muscle activation under movement correction conditions.

  16. The effects of wrist motion and hand orientation on muscle forces: A physiologic wrist simulator study.

    Science.gov (United States)

    Shah, Darshan S; Middleton, Claire; Gurdezi, Sabahat; Horwitz, Maxim D; Kedgley, Angela E

    2017-07-26

    Although the orientations of the hand and forearm vary for different wrist rehabilitation protocols, their effect on muscle forces has not been quantified. Physiologic simulators enable a biomechanical evaluation of the joint by recreating functional motions in cadaveric specimens. Control strategies used to actuate joints in physiologic simulators usually employ position or force feedback alone to achieve optimum load distribution across the muscles. After successful tests on a phantom limb, unique combinations of position and force feedback - hybrid control and cascade control - were used to simulate multiple cyclic wrist motions of flexion-extension, radioulnar deviation, dart thrower's motion, and circumduction using six muscles in ten cadaveric specimens. Low kinematic errors and coefficients of variation of muscle forces were observed for planar and complex wrist motions using both novel control strategies. The effect of gravity was most pronounced when the hand was in the horizontal orientation, resulting in higher extensor forces (pforces were also affected by the direction of rotation during circumduction. The peak force of flexor carpi radialis was higher in clockwise circumduction (p=0.017), while that of flexor carpi ulnaris was higher in anticlockwise circumduction (p=0.013). Thus, the physiologic wrist simulator accurately replicated cyclic planar and complex motions in cadaveric specimens. Moreover, the dependence of muscle forces on the hand orientation and the direction of circumduction could be vital in the specification of such parameters during wrist rehabilitation. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  17. Spatial localization of electromyographic amplitude distributions associated to the activation of dorsal forearm muscles

    Directory of Open Access Journals (Sweden)

    Alessio eGallina

    2013-12-01

    Full Text Available In this study we investigated whether the spatial distribution of surface electromyographic (EMG amplitude can be used to describe the activation of muscle portions with different biomechanical actions. Ten healthy subjects performed isometric contractions aimed to selectively activate a number of forearm muscles or muscle subportions. Monopolar electromyographic signals were collected with an electrode grid of 128 electrodes placed on the proximal, dorsal portion of the forearm. The monopolar EMG amplitude (root mean square value distribution was calculated for each contraction, and high-amplitude channels were identified through an automatic procedure; the position of the EMG source was estimated with the barycenter of these channels. Each of the contractions tested was associated to a specific EMG amplitude distribution, whose location in space was consistent with the expected anatomical position of the main agonist muscle (or subportion. The position of each source was significantly different from the others in at least one direction (ANOVA; transversally to the forearm: P < 0.01, F = 125.92; longitudinally: P < 0.01, F = 35.83. With such an approach, we could distinguish the spatial position of EMG distributions related to the activation of contiguous muscles (e.g.: extensor carpi ulnaris and extensor digitorum communis, different heads of the same muscle (i.e.: extensor carpi radialis brevis and longus and different functional compartments (i.e.: extensor digitorum communis, middle and ring fingers. These findings are discussed in terms of how forces along a given direction can be produced by recruiting population of motor units clustered not only in specific muscles, but also in muscle sub-portions. In addition, this study supports the use of high-density EMG systems to characterize the activation of muscle subportions with different biomechanical actions.

  18. Spatial localization of electromyographic amplitude distributions associated to the activation of dorsal forearm muscles

    Science.gov (United States)

    Gallina, Alessio; Botter, Alberto

    2013-01-01

    In this study we investigated whether the spatial distribution of surface electromyographic (EMG) amplitude can be used to describe the activation of muscle portions with different biomechanical actions. Ten healthy subjects performed isometric contractions aimed to selectively activate a number of forearm muscles or muscle subportions. Monopolar electromyographic signals were collected with an electrode grid of 128 electrodes placed on the proximal, dorsal portion of the forearm. The monopolar EMG amplitude [root mean square (RMS) value] distribution was calculated for each contraction, and high-amplitude channels were identified through an automatic procedure; the position of the EMG source was estimated with the barycenter of these channels. Each of the contractions tested was associated to a specific EMG amplitude distribution, whose location in space was consistent with the expected anatomical position of the main agonist muscle (or subportion). The position of each source was significantly different from the others in at least one direction (ANOVA; transversally to the forearm: P extensor carpi ulnaris (ECU) and extensor digitorum communis (EDC)], different heads of the same muscle (i.e., extensor carpi radialis (ECR) brevis and longus) and different functional compartments (i.e., EDC, middle, and ring fingers). These findings are discussed in terms of how forces along a given direction can be produced by recruiting population of motor units clustered not only in specific muscles, but also in muscle sub-portions. In addition, this study supports the use of high-density EMG systems to characterize the activation of muscle subportions with different biomechanical actions. PMID:24379788

  19. Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures.

    Directory of Open Access Journals (Sweden)

    Md Anamul Islam

    Full Text Available In mechanomyography (MMG, crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity.The aim of the present study was two-fold: i to quantify the level of crosstalk in the mechanomyographic (MMG signals from the longitudinal (Lo, lateral (La and transverse (Tr axes of the extensor digitorum (ED, extensor carpi ulnaris (ECU and flexor carpi ulnaris (FCU muscles during isometric wrist flexion (WF and extension (WE, radial (RD and ulnar (UD deviations; and ii to analyze whether the three-directional MMG signals influence the level of crosstalk between the muscle groups during these wrist postures.Twenty, healthy right-handed men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg participated in this study. During each wrist posture, the MMG signals propagated through the axes of the muscles were detected using three separate tri-axial accelerometers. The x-axis, y-axis, and z-axis of the sensor were placed in the Lo, La, and Tr directions with respect to muscle fibers. The peak cross-correlations were used to quantify the proportion of crosstalk between the different muscle groups.The average level of crosstalk in the MMG signals generated by the muscle groups ranged from: 34.28-69.69% for the Lo axis, 27.32-52.55% for the La axis and 11.38-25.55% for the Tr axis for all participants and their wrist postures. The Tr axes between the muscle groups showed significantly smaller crosstalk values for all wrist postures [F (2, 38 = 14-63, p<0.05, η2 = 0.416-0.769].The results may be applied in the field of human movement research, especially for the examination of muscle mechanics during various types of the wrist postures.

  20. Lower working heights decrease contraction intensity of shoulder muscles in a herringbone 30° milking parlor.

    Science.gov (United States)

    Cockburn, Marianne; Schick, Matthias; Maffiuletti, Nicola A; Gygax, Lorenz; Savary, Pascal; Umstätter, Christina

    2017-06-01

    Musculoskeletal disorders have been a main concern in milkers for many years. To improve posture, a formula was developed in a previous study to calculate ergonomically optimal working heights for various milking parlor types. However, the working height recommendations based on the formula for the herringbone 30° parlor were broad. To clarify the recommendations for the optimal working height, we investigated the effect of working height on upper limb and shoulder muscle contraction intensities. We evaluated 60 milking cluster attachment procedures in a herringbone 30° milking parlor in 7 men and 9 women. Specifically, we examined the effect of working height on muscle contraction intensity of 4 arm and shoulder muscles bilaterally (flexor carpi ulnaris, biceps brachii, deltoideus anterior, and upper trapezius) by using surface electromyography. The working heights (low, medium, and high), which reflect the ratio of the subject's height to the height of the udder base, were used in the milking health formula to determine and fit individual depth of pits. Data were evaluated for each muscle and arm side in the functions holding and attaching. Statistical analysis was performed using linear mixed effects models, where muscle contraction intensity served as a target variable, whereas working height coefficient, sex, subject height, and repetition were treated as fixed effects, and repetition group nested in working height nested in subject was considered a random effect. Contraction intensities decreased with decreasing working height for the deltoideus anterior and upper trapezius, but not for the flexor carpi ulnaris or the biceps brachii muscles in both holding and attaching arm functions. We found that milking at a lower working height reduced muscle contraction intensities of the shoulder muscles. Women showed higher contraction intensities than men, whereas subject height had no effect. The study demonstrated that a lower working height decreased muscular

  1. Development and Applications of a Self-Contained, Non-Invasive EVA Joint Angle and Muscle Fatigue Sensor System

    Science.gov (United States)

    Ranniger, C. U.; Sorenson, E. A.; Akin, D. L.

    1995-01-01

    The University of Maryland Space Systems Laboratory, as a participant in NASA's INSTEP program, is developing a non-invasive, self-contained sensor system which can provide quantitative measurements of joint angles and muscle fatigue in the hand and forearm. The goal of this project is to develop a system with which hand/forearm motion and fatigue metrics can be determined in various terrestrial and zero-G work environments. A preliminary study of the prototype sensor systems and data reduction techniques for the fatigue measurement system are presented. The sensor systems evaluated include fiberoptics, used to measure joint angle, surface electrodes, which measure the electrical signals created in muscle as it contracts; microphones, which measure the noise made by contracting muscle; and accelerometers, which measure the lateral muscle acceleration during contraction. The prototype sensor systems were used to monitor joint motion of the metacarpophalangeal joint and muscle fatigue in flexor digitorum superficialis and flexor carpi ulnaris in subjects performing gripping tasks. Subjects were asked to sustain a 60-second constant-contraction (isometric) exercise and subsequently to perform a repetitive handgripping task to failure. Comparison of the electrical and mechanical signals of the muscles during the different tasks will be used to evaluate the applicability of muscle signal measurement techniques developed for isometric contraction tasks to fatigue prediction in quasi-dynamic exercises. Potential data reduction schemes are presented.

  2. Dry needling for the treatment of poststroke muscle spasticity: a prospective case report.

    Science.gov (United States)

    Ansari, Noureddin Nakhostin; Naghdi, Soofia; Fakhari, Zahra; Radinmehr, Hojjat; Hasson, Scott

    2015-01-01

    Spasticity is a common symptom that can be detrimental to the quality of life and daily function of patients with stroke. To introduce the use of dry needling (DN) as a novel method for the treatment of affected upper limb spasticity in a patient with chronic ischemic stroke who was admitted at the Stroke Physiotherapy Clinic. The pronator teres (PT), flexor carpi radialis (FCR), and flexor carpi ulnaris (FCU) on the affected side were needled. The patient received deep DN for 1 session, and the duration of needling for each muscle was 1 minute. The main outcomes were the Modified Modified Ashworth Scale (MMAS) muscle spasticity score, and the Hmax/Mmax ratio which were measured before (T0), immediately after (T1), and 15 minutes after the end of needling (T2). The case was a 53-year-old man with a 13-year history of right hemiparesis poststroke. After DN, the spasticity scores improved and maintained as indicated in the MMAS grades (PT 3 to 2, finger flexors 1 to 0) and the Hmax/Mmax ratio (0.39, 0. 29, and 0.32 at T0, T1, and T2, respectively). The patient was able to voluntarily extend the wrist and fingers slightly after DN. The upper limb Brunnstrom recovery stage (3 to 4) and hand function (2 to 3) improved and maintained. The passive supination increased at T1 (75°) and T2 (50°) compared to T0 (38°). This prospective case report presents dry needling as a novel method in neurorehabilitation for the treatment of poststroke spasticity. Further research is recommended.

  3. Wide resection and stabilization of ulnar stump by extensor carpi ulnaris for giant cell tumor of distal ulna: two case reports.

    Science.gov (United States)

    Singh, Manjeet; Sharma, Siddhartha; Peshin, Chetan; Wani, Iftikhar H; Tikoo, Agnivesh; Gupta, Sanjeev K; Singh, Dara

    2009-07-21

    The distal end of ulna is an extremely uncommon site for primary bone tumors in general and giant cell tumor in particular. Wide resection is usually indicated in such cases and at times it may be necessary to remove of a long segment of the distal ulna. Any ulnar resection proximal to the insertion of pronator quadratus can lead to instability in the form of radio-ulnar convergence and dorsal displacement (winging) of the ulnar stump. This can result in diminution of forearm rotation and weakness with grasp. Stabilization of the ulnar stump after resection for a giant cell tumor was described by Kayias & Drosos. We are adding two more cases to the literature. Both patients had excellent functional outcome and there were no instances of recurrence at three years of follow-up.

  4. Wide resection and stabilization of ulnar stump by extensor carpi ulnaris for giant cell tumor of distal ulna: two case reports

    OpenAIRE

    Singh, Manjeet; Sharma, Siddhartha; Peshin, Chetan; Wani, Iftikhar H; Tikoo, Agnivesh; Gupta, Sanjeev K; Singh, Dara

    2009-01-01

    The distal end of ulna is an extremely uncommon site for primary bone tumors in general and giant cell tumor in particular. Wide resection is usually indicated in such cases and at times it may be necessary to remove of a long segment of the distal ulna. Any ulnar resection proximal to the insertion of pronator quadratus can lead to instability in the form of radio-ulnar convergence and dorsal displacement (winging) of the ulnar stump. This can result in diminution of forearm rotation and wea...

  5. Intramuscular connective tissue differences in spastic and control muscle: a mechanical and histological study.

    Directory of Open Access Journals (Sweden)

    Marije de Bruin

    Full Text Available Cerebral palsy (CP of the spastic type is a neurological disorder characterized by a velocity-dependent increase in tonic stretch reflexes with exaggerated tendon jerks. Secondary to the spasticity, muscle adaptation is presumed to contribute to limitations in the passive range of joint motion. However, the mechanisms underlying these limitations are unknown. Using biopsies, we compared mechanical as well as histological properties of flexor carpi ulnaris muscle (FCU from CP patients (n = 29 and healthy controls (n = 10. The sarcomere slack length (mean 2.5 µm, SEM 0.05 and slope of the normalized sarcomere length-tension characteristics of spastic fascicle segments and single myofibre segments were not different from those of control muscle. Fibre type distribution also showed no significant differences. Fibre size was significantly smaller (1933 µm2, SEM 190 in spastic muscle than in controls (2572 µm2, SEM 322. However, our statistical analyses indicate that the latter difference is likely to be explained by age, rather than by the affliction. Quantities of endomysial and perimysial networks within biopsies of control and spastic muscle were unchanged with one exception: a significant thickening of the tertiary perimysium (3-fold, i.e. the connective tissue reinforcement of neurovascular tissues penetrating the muscle. Note that this thickening in tertiary perimysium was shown in the majority of CP patients, however a small number of patients (n = 4 out of 23 did not have this feature. These results are taken as indications that enhanced myofascial loads on FCU is one among several factors contributing in a major way to the aetiology of limitation of movement at the wrist in CP and the characteristic wrist position of such patients.

  6. Differences in Muscle Activity During Cable Resistance Training Are Influenced by Variations in Handle Types.

    Science.gov (United States)

    Rendos, Nicole K; Heredia Vargas, Héctor M; Alipio, Taislaine C; Regis, Rebeca C; Romero, Matthew A; Signorile, Joseph F

    2016-07-01

    Rendos, NK, Heredia Vargas, HM, Alipio, TC, Regis, RC, Romero, MA, and Signorile, JF. Differences in muscle activity during cable resistance training are influenced by variations in handle types. J Strength Cond Res 30(7): 2001-2009, 2016-There has been a recent resurgence in the use of cable machines for resistance training allowing movements that more effectively simulate daily activities and sports-specific movements. By necessity, these devices require a machine/human interface through some type of handle. Considerable data from material handling, industrial engineering, and exercise training studies indicate that handle qualities, especially size and shape, can significantly influence force production and muscular activity, particularly of the forearm muscles, which affect the critical link in activities that require object manipulation. The purpose for this study was to examine the influence of three different handle conditions: standard handle (StandH), ball handle with the cable between the index and middle fingers (BallIM), and ball handle with the cable between the middle and ring fingers (BallMR), on activity levels (rmsEMG) of the triceps brachii lateral and long heads (TriHLat, TriHLong), brachioradialis (BR), flexor carpi radialis (FCR), extensor carpi ulnaris, and extensor digitorum (ED) during eight repetitions of standing triceps pushdown performed from 90° to 0° elbow flexion at 1.5 s per contractile stage. Handle order was randomized. No significant differences were seen for triceps or BR rmsEMG across handle conditions; however, relative patterns of activation did vary for the forearm muscles by handle condition, with more coordinated activation levels for the FCR and ED during the ball handle conditions. In addition, the rmsEMG for the ED was significantly higher during the BallIM than any other condition and during the BallMR than the StandH. These results indicate that the use of ball handles with the cable passing between different fingers

  7. Modulation of forelimb and hindlimb muscle activity during quadrupedal tied-belt and split-belt locomotion in intact cats.

    Science.gov (United States)

    Frigon, A; Thibaudier, Y; Hurteau, M-F

    2015-04-02

    The modulation of the neural output to forelimb and hindlimb muscles when the left and right sides step at different speeds from one another in quadrupeds was assessed by obtaining electromyography (EMG) in seven intact adult cats during split-belt locomotion. To determine if changes in EMG during split-belt locomotion were modulated according to the speed of the belt the limb was stepping on, values were compared to those obtained during tied-belt locomotion (equal left-right speeds) at matched speeds. Cats were chronically implanted for EMG, which was obtained from six muscles: biceps brachii, triceps brachii, flexor carpi ulnaris, sartorius, vastus lateralis and medial gastrocnemius. During tied-belt locomotion, cats stepped from 0.4 to 1.0m/s in 0.1m/s increments whereas during split-belt locomotion, cats stepped with left-right speed differences of 0.1 to 0.4m/s in 0.1m/s increments. During tied-belt locomotion, EMG burst durations and mean EMG amplitudes of all muscles respectively decreased and increased with increasing speed. During split-belt locomotion, there was a clear differential modulation of the EMG patterns between flexors and extensors and between the slow and fast sides. Changes in the EMG pattern of some muscles could be explained by the speed of the belt the limb was stepping on, while in other muscles there were clear dissociations from tied-belt values at matched speeds. Therefore, results show that EMG patterns during split-belt locomotion are modulated to meet task requirements partly via signals related to the stepping speed of the homonymous limb and from the other limbs. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. The effects of forearm fatigue on baseball fastball pitching, with implications about elbow injury.

    Science.gov (United States)

    Wang, Lin-Hwa; Lo, Kuo-Cheng; Jou, I-Ming; Kuo, Li-Chieh; Tai, Ta-Wei; Su, Fong-Chin

    2016-01-01

    This study investigated the contribution of flexor muscles to the forearm through fatigue; therefore, the differences in forearm mechanisms on the pitching motion in fastball were analysed. Fifteen baseball pitchers were included in this study. Ultrasonographical examination of participants' ulnar nerve in the cubital tunnel with the elbow extended and at 45°, 90° and 120° of flexion was carried. A three-dimensional motion analysis system with 14 reflective markers attached on participants was used for motion data collection. The electromyography system was applied over the flexor carpi ulnaris, flexor carpi radialis and extensor carpi radialis muscles of the dominant arm. Flexor carpi ulnaris muscle activity showed a significant difference during the acceleration phase, with a peak value during fastball post-fatigue (P = 0.02). Significant differences in the distance between ulnar nerve and medial condyle on throwing arm and non-throwing arm were observed as the distance increased with the elbow movement from 0° to 120° of flexion (P = 0.01). The significant increase of the flexor carpi ulnaris muscle activity might be responsible for maintaining the stability of the wrist joint. The increased diameter might compress the ulnar nerve and cause several pathological changes. Therefore, fatigue in baseball pitchers still poses a threat to the ulnar nerve because the flexor carpi ulnaris and flexor carpi radialis all originate from the medial side of the elbow, and the swelling tendons after fatigue might be a key point.

  9. Case study of Berengario da Carpi and Lorenzo de' Medici.

    Science.gov (United States)

    Lippi, D

    2017-09-01

    Jacopo Berengario da Carpi (c.1460-c.1530) made several important advances in anatomy, being universally considered the founder of 'animated anatomy' (anatomia animata). In addition to being a famous anatomist, Berengario was also a highly regarded surgeon. One of his famous clients was Lorenzo de' Medici, Duke of Urbino (1492-1519). In 1517, Lorenzo suffered a skull injury from an harquebus shot and Berengario was asked to come to his bedside. Lorenzo's case gave Berengario the opportunity to write his Tractatus de Fractura Calve sive Cranei, published in Bologna by Gerolamo Benedetti in 1518. Berengario addressed his treatise to Lorenzo himself. This illustrated monograph was the most original neurosurgical treatise at that time, as Berengario was able to cite both from contemporary information and from his own direct observation all possible kinds of skull fracture, including the relationship between the site of the lesions and the resulting neurological effects. At the end of the book, Berengario explained and illustrated the surgical equipment to be used in each case, depicting a drill previously unseen in a medical volume and providing the recipe for a human dressing, a kind of poultice made of mummified human remins, to be applied regularly to wounds. Lorenzo de' Medici died in 1519 and was buried in the Church of San Lorenzo in Florence. His corpse was exhumed in 1875 and 1947. The casts of his skull made on those occasions are now preserved in the museums of Florence University, and clearly show evidence of the wound. Read more about the stories behind this masterpiece in an essay online. © 2017 BJS Society Ltd Published by John Wiley & Sons Ltd.

  10. Parecoxib increases muscle pain threshold and relieves shoulder pain after gynecologic laparoscopy: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Zhang HF

    2016-09-01

    Full Text Available Hufei Zhang,1,* Xinhe Liu,2,* Hongye Jiang,3 Zimeng Liu,4 Xu-Yu Zhang,1 Hong-Zhe Xie,3 1Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 2Department of Anesthesiology, Shenzhen Hospital, University of Hong Kong, Shenzhen, 3Department of Obstetrics and Gynecology, 4Surgical Intensive Care Unit, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Objectives: Postlaparoscopic shoulder pain (PLSP remains a common problem after laparoscopies. The aim of this study was to investigate the correlation between pressure pain threshold (PPT of different muscles and PLSP after gynecologic laparoscopy, and to explore the effect of parecoxib, a cyclooxygenase-2 inhibitor, on the changes of PPT.Materials and methods: The patients were randomly allocated into two groups; group P and group C. In group P, parecoxib 40 mg was intravenously infused at 30 minutes before surgery and 8 and 20 hours after surgery. In group C, normal saline was infused at the corresponding time point. PPT assessment was performed 1 day before surgery and at postoperative 24 hours by using a pressure algometer at bilateral shoulder muscles (levator scapulae and supraspinatus and forearm (flexor carpi ulnaris. Meanwhile, bilateral shoulder pain was evaluated through visual analog scale score at 24 hours after surgery. Results: Preoperative PPT level of the shoulder, but not of the forearm, was significantly and negatively correlated with the intensity of ipsilateral PLSP. In group C, PPT levels of shoulder muscles, but not of forearm muscles, decreased after laparoscopy at postoperative 24 hours. The use of parecoxib significantly improved the decline of PPT levels of bilateral shoulder muscles (all P<0.01. Meanwhile, parecoxib reduced the incidence of PLSP (group P: 45% vs group C: 83.3%; odds ratio: 0.164; 95% confidence interval: 0.07–0.382; P<0

  11. Botulinum toxin injection into the forearm muscles for wrist and fingers spastic overactivity in adults with chronic stroke: a randomized controlled trial comparing three injection techniques.

    Science.gov (United States)

    Picelli, Alessandro; Lobba, Davide; Midiri, Alessandro; Prandi, Paolo; Melotti, Camilla; Baldessarelli, Silvia; Smania, Nicola

    2014-03-01

    To compare the outcome of manual needle placement, electrical stimulation and ultrasonography-guided techniques for botulinum toxin injection into the forearm muscles of adults with arm spasticity. Randomized controlled trial. University hospital. Sixty chronic stroke patients with wrist and fingers spasticity. After randomization into three groups, each patient received botulinum toxin type A in at least two of these muscles: flexor carpi radialis and ulnaris, flexor digitorum superficialis and profundus (no fascicles selection). The manual needle placement group underwent injections using palpation; the electrical stimulation group received injections with electrical stimulation guidance; the ultrasonography group was injected under sonographic guidance. A sole injector was used. All patients were evaluated at baseline and four weeks after injection. Modified Ashworth Scale; Tardieu Scale; wrist and fingers passive range of motion. One month after injection, Modified Ashworth Scale scores improved more in the electrical stimulation group than the manual needle placement group (wrist: P = 0.014; fingers: P = 0.011), as well as the Tardieu angle (wrist: P = 0.008; fingers: P = 0.015) and passive range of motion (wrist: P = 0.004). Furthermore, Modified Ashworth Scale scores improved more in the ultrasonography group than in the manual needle placement group (wrist: P = 0.001; fingers: P = 0.003), as well as the Tardieu angle (wrist: P = 0.010; fingers: P = 0.001) and passive range of motion (wrist: P < 0.001; proximal interphalangeal joints: P = 0.009). No difference was found between the ultrasonography and electrical stimulation groups. Instrumental guidance may improve the outcome of botulinum toxin injections into the spastic forearm muscles of stroke patients.

  12. Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats.

    Science.gov (United States)

    Tudury, Eduardo Alberto; de Figueiredo, Marcella Luiz; Fernandes, Thaiza Helena Tavares; Araújo, Bruno Martins; Bonelli, Marília de Albuquerque; Diogo, Camila Cardoso; Silva, Amanda Camilo; Santos, Cássia Regina Oliveira; Rocha, Nadyne Lorrayne Farias Cardoso

    2017-02-01

    Objectives This study aimed to test the extensor carpi radialis and cranial tibial reflexes in cats before and after anesthetic block of the brachial and lumbosacral plexus, respectively, to determine whether they depend on a myotatic reflex arc. Methods Fifty-five cats with a normal neurologic examination that were referred for elective gonadectomy were divided into group 1 (29 cats) for testing the extensor carpi radialis reflex, and group 2 (26 cats) for testing the cranial tibial reflex. In group 1, the extensor carpi radialis reflex was tested after anesthetic induction and 15 mins after brachial plexus block with lidocaine. In group 2, the cranial tibial, withdrawal and patellar reflexes were elicited in 52 hindlimbs and retested 15 mins after epidural anesthesia. Results In group 1, before the anesthetic block, 55.17% of the cats had a decreased and 44.83% had a normal extensor carpi radialis reflex. After the block, 68.96% showed a decreased and 27.59% a normal reflex. No cat had an increased or absent reflex before anesthetic block. In group 2, prior to the anesthetic block, 15.38% of the cats had a decreased cranial tibial reflex and 84.62% had a normal response, whereas after the block it was decreased in 26.92% and normal in 73.08% of the cats. None of the cats had an increased or absent reflex. Regarding the presence of both reflexes before and after anesthetic block, there was no significant difference at 1% ( P = 0.013). Conclusions and relevance The extensor carpi radialis and cranial tibial reflexes in cats are not strictly myotatic reflexes, as they are independent of the reflex arc, and may be idiomuscular responses. Therefore, they are not reliable for neurologic examination in this species.

  13. Enthesopathy of the Extensor Carpi Radialis Brevis Origin: Effective Communication Strategies.

    Science.gov (United States)

    Drake, Matthew L; Ring, David C

    2016-06-01

    Enthesopathy of the extensor carpi radialis brevis origin, generally known as tennis elbow, is a common condition arising in middle-aged persons. The diagnosis is typically clear based on the patient interview and physical examination alone; therefore, imaging and other diagnostic tests are usually unnecessary. The natural history of the disorder is spontaneous resolution, but it can last for >1 year. The patient's attitude and circumstances, including stress, distress, and ineffective coping strategies, determine the intensity of the pain and the magnitude of the disability. Despite the best efforts of medical science, no treatments, invasive or noninvasive, have been proven to alter the natural history of the condition. Given the lack of disease-modifying treatments for enthesopathy of the extensor carpi radialis brevis origin, orthopaedic surgeons can benefit from learning effective communication strategies to help convey accurate information that is hopeful and enabling.

  14. Anatomical study on The Arm Greater Yang Small Intestine Meridian Muscle in Human

    Directory of Open Access Journals (Sweden)

    Kyoung-Sik, Park

    2004-06-01

    Full Text Available This study was carried to identify the component of Small Intestine Meridian Muscle in human, dividing the regional muscle group into outer, middle, and inner layer. the inner part of body surface were opened widely to demonstrate muscles, nerve, blood vessels and the others, displaying the inner structure of Small Intestine Meridian Muscle. We obtained the results as follows; 1. Small Intestine Meridian Muscle is composed of the muscle, nerve and blood vessels. 2. In human anatomy, it is present the difference between a term of nerve or blood vessels which control the muscle of Meridian Muscle and those which pass near by Meridian Muscle. 3. The inner composition of meridian muscle in human arm is as follows ; 1 Muscle ; Abd. digiti minimi muscle(SI-2, 3, 4, pisometacarpal lig.(SI-4, ext. retinaculum. ext. carpi ulnaris m. tendon.(SI-5, 6, ulnar collateral lig.(SI-5, ext. digiti minimi m. tendon(SI-6, ext. carpi ulnaris(SI-7, triceps brachii(SI-9, teres major(SI-9, deltoid(SI-10, infraspinatus(SI-10, 11, trapezius(Sl-12, 13, 14, 15, supraspinatus(SI-12, 13, lesser rhomboid(SI-14, erector spinae(SI-14, 15, levator scapular(SI-15, sternocleidomastoid(SI-16, 17, splenius capitis(SI-16, semispinalis capitis(SI-16, digasuicus(SI-17, zygomaticus major(Il-18, masseter(SI-18, auriculoris anterior(SI-19 2 Nerve ; Dorsal branch of ulnar nerve(SI-1, 2, 3, 4, 5, 6, br. of mod. antebrachial cutaneous n.(SI-6, 7, br. of post. antebrachial cutaneous n.(SI-6,7, br. of radial n.(SI-7, ulnar n.(SI-8, br. of axillary n.(SI-9, radial n.(SI-9, subscapular n. br.(SI-9, cutaneous n. br. from C7, 8(SI-10, 14, suprascapular n.(SI-10, 11, 12, 13, intercostal n. br. from T2(SI-11, lat. supraclavicular n. br.(SI-12, intercostal n. br. from C8, T1(SI-12, accessory n. br.(SI-12, 13, 14, 15, 16, 17, intercostal n. br. from T1,2(SI-13, dorsal scapular n.(SI-14, 15, cutaneous n. br. from C6, C7(SI-15, transverse cervical n.(SI-16, lesser occipital n. & great auricular n. from

  15. Fatigue effects on tracking performance and muscle activity

    NARCIS (Netherlands)

    Huysmans, M.A.; Hoozemans, M.J.M.; van der Beek, A.J.; de Looze, M.P.; van Dieen, J.H.

    2008-01-01

    It has been suggested that fatigue affects proprioception and consequently movement accuracy, the effects of which may be counteracted by increased muscle activity. To determine the effects of fatigue on tracking performance and muscle activity in the M. extensor carpi radialis (ECR), 11 female

  16. The minimally invasive flexor carpi radialis approach: a new perspective for distal radius fractures.

    Science.gov (United States)

    Igeta, Yuka; Vernet, Paul; Facca, Sybille; Naroura, Ismaël; Diaz, Juan José Hidalgo; Liverneaux, Philippe A

    2018-01-24

    The minimally invasive flexor carpi radialis approach can be used for volar locking plate fixation of distal radius fractures. After 15-mm incision on the lateral aspect of the FCR tendon and all structures but the radial artery are reclined ulnarly, a plate is inserted under the pronator quadratus just proximal to the "watershed line." The distal epiphyseal screws are put in place, and the proximal part of the plate is exposed by flexion of the wrist to put in place the proximal screws. No drainage or postoperative immobilization is used. It offers the advantage of preserving ligamentotaxis which facilitates the reduction, and the small size of the scar improves the esthetic result of the procedure. It is indicated for extra-articular fractures of the distal radius. In the case of an intraarticular fracture, an arthroscopy may be associated. In the case of a proximal diaphyseal extension of the fracture, a second proximal approach can be added in order to use a longer plate. Relative contraindications are comminuted articular fractures in elderly osteoporotic patients. Functional and radiological results are comparable to those obtained with the extented flexor carpi radialis approach. A conversion of the procedure for a larger incision is always possible in the case of a difficult reduction.

  17. Bone and muscular anatomy of the forearm and hand in Tapirus terrestris (Perissodactyla, Tapiridae

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    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.

  18. 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.

  19. Ischemia causes muscle fatigue

    Science.gov (United States)

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D. M.

    2001-01-01

    The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle, causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blood volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 +/- 9.8 mm Hg) and systolic (106 +/- 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3-5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 +/- 1.2% (SEM), 96 +/- 1.9%, 93 +/- 2.8%, 90 +/- 2.5%, and 86 +/- 2.7%, and mean twitch force decreased from resting baseline (100% force) to 99 +/- 0.7% (SEM), 96 +/- 2.7%, 93 +/- 3.1%, 88 +/- 3.2%, and 86 +/- 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P muscle oxygenation (r = 0.78, P muscle oxygenation causes decreased muscle force production in the forearm extensor muscle. Thus, ischemia associated with a modest decline in TO2 causes muscle fatigue.

  20. Muscle dependency of corticomuscular coherence in upper and lower limb muscles and training-related alterations in ballet dancers and weightlifters.

    Science.gov (United States)

    Ushiyama, Junichi; Takahashi, Yuji; Ushiba, Junichi

    2010-10-01

    It has been well documented that the 15- to 35-Hz oscillatory activity of the sensorimotor cortex shows coherence with the muscle activity during weak to moderate steady contraction. To investigate the muscle dependency of the corticomuscular coherence and its training-related alterations, we quantified the coherence between electroencephalogram (EEG) from the sensorimotor cortex and rectified electromyogram (EMG) from five upper limb (first dorsal interosseous, flexor carpi radialis, extensor carpi radialis, biceps brachii, triceps brachii) and four lower limb muscles (soleus, tibialis anterior, biceps femoris, rectus femoris), while maintaining a constant force level at 30% of maximal voluntary contraction of each muscle, in 24 untrained, 12 skill-trained (ballet dancers), and 10 strength-trained (weightlifters) individuals. Data from untrained subjects demonstrated the muscle dependency of corticomuscular coherence. The magnitude of the EEG-EMG coherence was significantly greater in the distally located lower limb muscles, such as the soleus and tibialis anterior, than in the upper or other lower limb muscles in untrained subjects (P muscles, according to the functional role of each muscle. In addition, the ballet dancers and weightlifters showed smaller EEG-EMG coherences than the untrained subjects, especially in the lower limb muscles (P muscles and that this neural adaptation may lead to finer control of muscle force during steady contraction.

  1. Avulsion Fractures at the Base of the 2nd Metacarpal Due to the Extensor Carpi Radialis Longus Tendon: A Case Report and Review of the Literature

    OpenAIRE

    Najefi, Ali; Jeyaseelan, Lucksmana; Patel, Anand; Kapoor, Akhil; Auplish, Sunil

    2016-01-01

    Introduction Simultaneous contraction of the extensor carpi radialis longus (ECRL) with forced hyperflexion of the wrist can result in avulsion of the tendon and its bony attachment at its insertion at the dorsum of the base of the second metacarpal. This is a rare and often unreported fracture pattern. Case Presentation We present a 31- year- old male who sustained a hyperflexion injury. He was managed surgically and had good pos...

  2. Nuevos puñales de remaches de bronce procedentes de La Mesa de Carpió (Villagonzalo de Tormes, Salamanca

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    Pedro Javier CRUZ SÁNCHEZ

    2009-12-01

    Full Text Available RESUMEN: La aparición en las siembras de La Mesa de Carpió (Villagonzalo de Tormes, Salamanca de un nutrido lote de acabados metálicos encuadrados en la Edad del Bronce, entre ellos el par de cuchillos de roblones que analizamos, así como una serie de evidencias relacionadas con una actividad fundidora a pequeña escala, dan pie a plantear algunas hipótesis sobre una presunta jerarquía de poblamiento durante el Bronce Final en el valle medio del Tormes, cuyo centro capitalizador, sede de una emergente élite social, se encontraría en la propia Mesa de Carpió.ABSTRACT: The come out of a considerable amount of metalwork in La Mesa de Carpió fields belonging to Bronze Age (such as that couple of flat-rivetted bronze-daggers which are the object of our study, in addition to a serie of evidences in relationship with a small-scale bronze metalwork; it helps to set up some thoughts about an hypothetical hierarchy of settlements, during the Late Bronze Age in the Tormes middle valley. The main centre, head of an emerging social elite, would be placed in La Mesa de Carpios itself.

  3. Clinical and radiographic changes of carpi, tarsi and interphalangeal joints of beef zebu bulls on semen collection regimen

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    G.A. Motta

    Full Text Available ABSTRACT Osteoarthritis and osteochondrosis are highly correlated to reproductive failure in bulls. This study aimed to evaluate the carpal, tarsal and interphalangeal lesions in beef zebu bulls on semen collection regimen. Twenty-one beef cattle bulls, in a total of forty-one animals, were split into three age-based groups: animals from two to four years old (GI, from more than four to eight years old (GII and above eight years old (GIII. The clinical findings were conformational changes of limbs, synovial effusion, peripheral venous engorgement of joints and prolonged decubitus. The total population showed moderate clinical manifestation and radiographic score. The GIII presented more severe joint lesions. Carpi and tarsi regions had discrete to difuse osteophytosis, subchondral cysts, cartilaginous flaps, bone incongruence and fragmentation, osteitis, and ankylosis. Interphalangeal joints presented osteophytosis, distal phalanx osteitis and enthesophytosis. The digital radiographic examination allowed full identification of articular lesions and their clinical correspondences, besides the positive correlation between age, body weight and radiographic score.

  4. [Tremor Suppression on Multi-DoF Wrist Joint Based on Functional Electrical Stimulation: A Simulation Study].

    Science.gov (United States)

    Zhang, Wei; Zhang, Dingguo; Liu, Jianrong

    2015-04-01

    An automatic control system was designed to suppress pathological tremor on wrist joint with two degrees of freedom (DoF) using functional electrical stimulation (FES). The tremor occurring in the wrist flexion-extension and adduction-abduction was expected to be suppressed. A musculoskeletal model of wrist joint was developed to serve as the control plant, which covered four main muscles (extensor carpi radialis longus, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris). A second-order mechanical impedance model was used to describe the wrist skeletal dynamics. The core work was to design the controller and a hybrid control strategy was proposed, which combined inverse model based on feed forward control and linear quadratic regulator (LQR) optimal control. Performance of the system was tested under different input conditions (step signal, sinusoidal signal, and real data of a patient)., The results indicated that the proposed hybrid controller could attenuate over 94% of the tremor amplitude on multi-DoF wrist joint.

  5. Muscle Relaxation of the Foot Reduces Corticospinal Excitability of Hand Muscles and Enhances Intracortical Inhibition

    Science.gov (United States)

    Kato, Kouki; Muraoka, Tetsuro; Mizuguchi, Nobuaki; Nakagawa, Kento; Nakata, Hiroki; Kanosue, Kazuyuki

    2016-01-01

    The object of this study was to clarify the effects of foot muscle relaxation on activity in the primary motor cortex (M1) of the hand area. Subjects were asked to volitionally relax the right foot from sustained contraction of either the dorsiflexor (tibialis anterior; TA relaxation) or plantarflexor (soleus; SOL relaxation) in response to an auditory stimulus. Single- and paired-pulse transcranial magnetic stimulation (TMS) was delivered to the hand area of the left M1 at different time intervals before and after the onset of TA or SOL relaxation. Motor evoked potentials (MEPs) were recorded from the right extensor carpi radialis (ECR) and flexor carpi radialis (FCR). MEP amplitudes of ECR and FCR caused by single-pulse TMS temporarily decreased after TA and SOL relaxation onset, respectively, as compared with those of the resting control. Furthermore, short-interval intracortical inhibition (SICI) of ECR evaluated with paired-pulse TMS temporarily increased after TA relaxation onset. Our findings indicate that muscle relaxation of the dorsiflexor reduced corticospinal excitability of the ipsilateral hand muscles. This is most likely caused by an increase in intracortical inhibition. PMID:27242482

  6. Muscle relaxation of the foot reduces corticospinal excitability of hand muscles and enhances intracortical inhibition

    Directory of Open Access Journals (Sweden)

    Kouki eKato

    2016-05-01

    Full Text Available The object of this study was to clarify the effects of foot muscle relaxation on activity in the primary motor cortex of the hand area. Subjects were asked to volitionally relax the right foot from sustained contraction of either the dorsiflexor (tibialis anterior; TA relaxation or plantarflexor (soleus; SOL relaxation in response to an auditory stimulus. Single- and paired-pulse transcranial magnetic stimulation (TMS was delivered to the hand area of the left primary motor cortex at different time intervals before and after the onset of TA or SOL relaxation. Motor evoked potentials (MEPs were recorded from the right extensor carpi radialis (ECR and flexor carpi radialis (FCR. MEP amplitudes of ECR and FCR caused by single-pulse TMS temporarily decreased after TA and SOL relaxation onset, respectively, as compared with those of the resting control. Furthermore, short-interval intracortical inhibition (SICI of ECR evaluated with paired-pulse TMS temporarily increased after TA relaxation onset. Our findings indicate that muscle relaxation of the dorsiflexor reduced corticospinal excitability of the ipsilateral hand muscles. This is most likely caused by an increase in intracortical inhibition.

  7. Intermuscular aponeuroses between the flexor muscles of the forearm and their relationships with the ulnar nerve.

    Science.gov (United States)

    Won, Hyung-Sun; Liu, Hong-Fu; Kim, Jun-Ho; Kwak, Dai-Soon; Chung, In-Hyuk; Kim, In-Beom

    2016-12-01

    The aim of this study was to clarify the morphological characteristics of the intermuscular aponeurosis between the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS; IMAS), and that between the FCU and flexor digitorum profundus (FDP; IMAP), and their topographic relationships with the ulnar nerve. Fifty limbs of 38 adult cadavers were studied. The IMAS extended along the deep surface of the FCU adjoining the FDS, having the appearance of a ladder, giving off "steps" that decreased in width from superficial to deep around the middle of the forearm. Its proximal part divided into two bands connected by a thin membrane, and was attached to the medial epicondyle and the tubercle (the most medial prominent part of the coronoid process of the ulna), respectively. The IMAP extended deep between the FCU and FDP from the antebrachial fascia, and its distal end was located on the posterior border of the FCU. The IMAP became broader toward its proximal part, and its proximal end was attached anterior and posterior to the tubercle and the olecranon, respectively. The ulnar nerve passed posterior to the medial epicondyle and then medial to the tubercle, and was crossed by the deep border of the IMAS at 58.3 ± 14.1 mm below the medial epicondyle. The deep border of the IMAS and aberrant tendinous structure passing across the ulnar nerve, or the parts of the IMAS and IMAP passing posterior to the ulnar nerve are potential causes of ulnar nerve compression.

  8. Common elbow conditions

    African Journals Online (AJOL)

    2011-09-02

    Sep 2, 2011 ... Anatomy. The tendons of extensor carpi radialis longus, extensor carpi radialis brevis (ECRB), extensor digitorum communis and the extensor carpi ulnaris make ... Pain is sited over the lateral epicondyle and radiates down the forearm along the ... Pain may also occur with passive pronation of the forearm.

  9. Adaptations in corticospinal excitability and inhibition are not spatially confined to the agonist muscle following strength training.

    Science.gov (United States)

    Mason, Joel; Frazer, Ashlyn; Horvath, Deanna M; Pearce, Alan J; Avela, Janne; Howatson, Glyn; Kidgell, Dawson

    2017-07-01

    We used transcranial magnetic stimulation (TMS) to determine the corticospinal responses from an agonist and synergist muscle following strength training of the right elbow flexors. Motor-evoked potentials were recorded from the biceps brachii and flexor carpi radialis during a submaximal contraction from 20 individuals (10 women, 10 men, aged 18-35 years; training group; n = 10 and control group; n = 10) before and after 3 weeks of strength training at 80% of 1-repetition maximum (1-RM). To characterise the input-output properties of the corticospinal tract, stimulus-response curves for corticospinal excitability and inhibition of the right biceps brachii and flexor carpi radialis were constructed and assessed by examining the area under the recruitment curve (AURC). Strength training resulted in a 29% (P strength and this was accompanied by a 19% increase in isometric strength of the wrist flexors (P = 0.001). TMS revealed an increase in corticospinal excitability AURC and a decrease in silent period duration AURC for the biceps brachii and flexor carpi radialis following strength training (all P strength. These findings show that the corticospinal responses to strength training of a proximal upper limb muscle are not spatially restricted, but rather, results in a change in connectivity, among an agonist and a synergistic muscle relevant to force production.

  10. Evaluation of surgeon's muscle fatigue during thoracoscopic pulmonary lobectomy using interoperative surface electromyography.

    Science.gov (United States)

    Yoon, Seung-Hyun; Jung, Myung-Chul; Park, Seong Yong

    2016-06-01

    The aim of this study was to document the physical stress experienced by a surgeon during thoracoscopic pulmonary lobectomy and mediastinal lymph node dissection for lung cancer by measuring the intraoperative electromyography (EMG). Surface EMG was recorded during 12 cases of thoracoscopic lobectomy. During the operation, 16 channels of a wireless EMG were used to measure muscle activity and fatigue from the bilateral muscles of the splenius capitis (SC), upper trapezius (UT), middle deltoid (MD), flexor carpi radialis (FCR), extensor carpi radialis (ECR), lumbar erector spinae (LES), rectus femoralis (RF), and tibialis anterior (TA). The EMG signals were processed to collect the values of the root mean square for muscle activity and median frequency (MF) for muscle fatigue. All operations were completed without adverse events. The mean operating time was 99.16±35.15 minutes. During the operation, the mean muscle activity of all muscles was 21.91±12.85 mV. High muscle activity was observed in the bilateral FCR and ECR, whereas low muscle activity was observed in the bilateral SC and LES. The final MFs in the bilateral SC and LES were found to be decreased from the initial status, which implied increased muscle fatigue. The muscles of the right and left LES were significantly fatigued by up to 29% and 37% compared to their initial status (P=0.021 and P=0.007, respectively). The MFs of the bilateral LES decreased with time (an average decreases of 0.008/5 minutes, P=0.002 in right LES and 0.004/5 minutes, P=0.018 in left LES). During thoracoscopic lobectomy, muscle fatigue was observed in muscles related to a static posture, such as the bilateral SC, UT, and ES. Further studies are required to investigate the ergonomic adjustments needed to reduce muscle fatigue in these static muscles.

  11. Contribution from motor unit firing adaptations and muscle co-activation during fatigue.

    Science.gov (United States)

    Contessa, Paola; Letizi, John; De Luca, Gianluca; Kline, Joshua C

    2018-03-14

    The control of motor unit firing behavior during fatigue is still debated in the literature. Most studies agree that the central nervous system increases the excitation to the motoneuron pool to compensate for decreased force contributions of individual motor units and sustain muscle force output during fatigue. However, some studies claim that motor units may decrease their firing rates despite increased excitation, contradicting the direct relationship between firing rates and excitation that governs the voluntary control of motor units. To investigate whether the control of motor units in fact changes with fatigue, we measured motor unit firing behavior during repeated contractions of the first dorsal interosseous (FDI) muscle while concurrently monitoring the activation of surrounding muscles - including the flexor carpi radialis, extensor carpi radialis, and pronator teres. Across all subjects, we observed an overall increase in FDI activation and motor unit firing rates by the end of the fatigue task. However, in some subjects we observed increases in FDI activation and motor unit firing rates only during the initial phase of the fatigue task, followed by subsequent decreases during the late phase of the fatigue task while the co-activation of surrounding muscles increased. These findings indicate that the strategy for sustaining force output may occasionally change leading to increases in the relative activation of surrounding muscles while the excitation to the fatiguing muscle decreases. Importantly, irrespective of changes in the strategy for sustaining force output, the control properties regulating motor unit firing behavior remain unchanged during fatigue.

  12. Influence of fatigue on upper limb muscle activity and performance in tennis.

    Science.gov (United States)

    Rota, Samuel; Morel, Baptiste; Saboul, Damien; Rogowski, Isabelle; Hautier, Christophe

    2014-02-01

    The study examined the fatigue effect on tennis performance and upper limb muscle activity. Ten players were tested before and after a strenuous tennis exercise. Velocity and accuracy of serve and forehand drives, as well as corresponding surface electromyographic (EMG) activity of eight upper limb muscles were measured. EMG and force were also evaluated during isometric maximal voluntary contractions (IMVC). Significant decreases were observed after exercise in serve accuracy (-11.7%) and velocity (-4.5%), forehand accuracy (-25.6%) and consistency (-15.6%), as well as pectoralis major (PM) and flexor carpi radialis (FCR) IMVC strength (-13.0% and -8.2%, respectively). EMG amplitude decreased for PM and FCR in serve, forehand and IMVC, and for extensor carpi radialis in forehand. No modification was observed in EMG activation timing during strokes or in EMG frequency content during IMVC. Several hypotheses can be put forward to explain these results. First, muscle fatigue may induce a reduction in activation level of PM and forearm muscles, which could decrease performance. Second, conscious or subconscious strategies could lead to a redistribution of muscle activity to non-fatigued muscles in order to protect the organism and/or limit performance losses. Otherwise, the modifications of EMG activity could also illustrate the strategies adopted to manage the speed-accuracy trade-off in such a complex task. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. A comparison of surgeon's postural muscle activity during robotic-assisted and laparoscopic rectal surgery.

    Science.gov (United States)

    Szeto, Grace P Y; Poon, Jensen T C; Law, Wai-Lun

    2013-09-01

    This study compared the muscular activity in the surgeon's neck and upper limbs during robotic-assisted laparoscopic (R-Lap) surgery and conventional laparoscopic (C-Lap) surgery. Two surgeons performed the same procedure of R-Lap and C-Lap low anterior resection, and real-time surface electromyography was recorded in bilateral cervical erector spinae, upper trapezius (UT) and anterior deltoid muscles for over 60 min in each procedure. In one surgeon, forearm muscle activities were also recorded during robotic surgery. Similar levels of cervical muscle activity were demonstrated in both types of surgery. One surgeon showed much higher activity in the left UT muscle during robotic surgery. In the second surgeon, C-Lap was associated with much higher levels of muscle activity in both UT muscles. This may be related to the bilateral abducted arm posture required in maneuvering the laparoscopic instruments. In the forearm region, the "ulnaris" muscles for wrist flexion and extension bilaterally showed high amplitudes during robotic-assisted surgery. Robotic-assisted surgery seemed to demand a higher level of muscle work in the forearm region while greater efforts of shoulder muscles were involved during laparoscopic surgery. There are also individual variations in postural habits and motor control that can affect the muscle activation patterns. This study demonstrated a method of objectively examining the surgeon's physical workload during real-time surgery in the operating theatre, and further research should explore the surgeon's workload in a larger group of surgeons performing different surgical procedures.

  14. Hand movements classification for myoelectric control system using adaptive resonance theory.

    Science.gov (United States)

    Jahani Fariman, H; Ahmad, Siti A; Hamiruce Marhaban, M; Alijan Ghasab, M; Chappell, Paul H

    2016-03-01

    This research proposes an exploratory study of a simple, accurate, and computationally efficient movement classification technique for prosthetic hand application. Surface myoelectric signals were acquired from the four muscles, namely, flexor carpi ulnaris, extensor carpi radialis, biceps brachii, and triceps brachii, of four normal-limb subjects. The signals were segmented, and the features were extracted with a new combined time-domain feature extraction method. Fuzzy C-means clustering method and scatter plot were used to evaluate the performance of the proposed multi-feature versus Hudgins' multi-feature. The movements were classified with a hybrid Adaptive Resonance Theory-based neural network. Comparative results indicate that the proposed hybrid classifier not only has good classification accuracy (89.09%) but also a significantly improved computation time.

  15. Avulsion Fractures at the Base of the 2(nd) Metacarpal Due to the Extensor Carpi Radialis Longus Tendon: A Case Report and Review of the Literature.

    Science.gov (United States)

    Najefi, Ali; Jeyaseelan, Lucksmana; Patel, Anand; Kapoor, Akhil; Auplish, Sunil

    2016-03-01

    Simultaneous contraction of the extensor carpi radialis longus (ECRL) with forced hyperflexion of the wrist can result in avulsion of the tendon and its bony attachment at its insertion at the dorsum of the base of the second metacarpal. This is a rare and often unreported fracture pattern. We present a 31- year- old male who sustained a hyperflexion injury. He was managed surgically and had good post-operative outcomes. A literature search revealed 16 papers covering 18 cases of similar injuries. 12 were initially managed surgically and 6 were managed conservatively. Of the open reductions and internal fixations, 11 (92%) were successful and patients made a full recovery. Conservative management was unsuccessful in 4 cases; one patient required surgery for metacarpal boss, one patient had retraction of the tendon at one week follow up and another had weak flexion of the wrist. We recommend open reduction and internal fixation for these injuries. It may allow a faster recovery and therefore allow an earlier return to work and activity.

  16. Changes of muscular load with aging in the motion of pulling up disposable diapers.

    Science.gov (United States)

    Yoto, Tsuyoshi Yi; Sakuragawa, Satoshi; Suzuki, Taka-aki; Tamura, Hisae; Yamaki, Rumi; Fujioka, Yoshihisa; Katsuura, Tetsuo

    2010-01-01

    To elucidate how aging affects the muscular load required for pulling up pants-style disposable diapers, and why some elderly people cannot pull up the rear of their disposable diapers well, we evaluated the electromyogram (EMG) of 8 young subjects (21.5+/-1.5 years) and 7 elderly subjects (71.6+/-6.1 years). EMG was measured for four muscles--biceps brachii, deltoid, brachioradialis, and flexor carpi ulnaris. We evaluated the muscular load during a series of motions for pulling a disposable diaper up at the front and the rear of the body using an EMG-Video Synchronous Split Method. The analysis revealed that the front and the rear integral EMG of elderly subjects were both significantly larger than those of young subjects for all four muscles. For the deltoid and flexor carpi ulnaris muscles, the maximum amplitude of EMG when pulling up the rear of the disposable diapers was significantly larger in the elderly subjects than the young ones. These results suggest that the muscular load involved in pulling up the rear of disposable diapers may increase due to changes in body habitus caused by aging. Since muscular strength decreases with age, it seems likely that the elderly individuals will eventually be unable to pull up the rear of their diapers.

  17. 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.

  18. Motor imagery of voluntary muscle relaxation of the foot induces a temporal reduction of corticospinal excitability in the hand.

    Science.gov (United States)

    Kato, Kouki; Kanosue, Kazuyuki

    2018-03-06

    The object of this study was to clarify how the motor imagery of foot muscle relaxation influences corticospinal excitability for the ipsilateral hand. Twelve participants volitionally relaxed their right foot from a dorsiflexed position (actual relaxation), or imaged the same movement (imagery relaxation) in response to an auditory cue. Transcranial magnetic stimulation (TMS) was delivered to the hand area of the left primary motor cortex at different time intervals after an auditory cue. Motor evoked potentials (MEPs) were recorded from the right extensor carpi radialis (ECR) and flexor carpi radialis (FCR). MEP amplitudes of ECR and FCR caused by single-pulse TMS temporarily decreased during both actual relaxation and imagery relaxation as compared with those of the resting control. A correlation of MEP amplitude between actual relaxation and imagery relaxation was observed. Our findings indicate that motor imagery of muscle relaxation of the foot induced a reduction of corticospinal excitability in the ipsilateral hand muscles. This effect is likely produced via the same mechanism that functions during actual muscle relaxation. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Stenosing tenosynovitis

    OpenAIRE

    Vuillemin, V.; Guerini, H.; Bard, H.; Morvan, G.

    2012-01-01

    Tenosynovitis refers to an inflammatory condition involving the synovial sheath of a tendon. Stenosing tenosynovitis is a peculiar entity caused by multiple factors, including local anatomy, mechanical factors, and hormonal factors. The main forms include de Quervain tendinopathy; trigger finger (stenosing tenosynovitis involving the flexor digitorum tendons); stenosing tenosynovitis of the extensor carpi ulnaris, extensor carpi radialis, or extensor comunis tendons; stenosing tenosynovitis o...

  20. Origins and branchings of the brachial plexus of the gray brocket deer Mazama gouazoubira (Artiodactyla: Cervidae

    Directory of Open Access Journals (Sweden)

    Lucélia Gonçalves Vieira

    2013-03-01

    Full Text Available The brachial plexus is a set of nerves originated in the cervicothoracic medular region which innervates the thoracic limb and its surroundings. Its study in different species is important not only as a source of morphological knowledge, but also because it facilitates the diagnosis of neuromuscular disorders resulting from various pathologies. This study aimed to describe the origins and branchings of the brachial plexus of Mazama gouazoubira. Three specimens were used, belonging to the scientific collection of the Laboratory for Teaching and Research on Wild Animals of Universidade Federal de Uberlandia (UFU; they were fixed in 3.7% formaldehyde and dissected. In M. gouazoubira, the brachial plexus resulted from connections between the branches of the three last cervical spinal nerves, C6, C7, C8, and the first thoracic one, T1, and it had as derivations the nerves suprascapular, cranial and caudal subscapular, axillary, musculocutaneous, median, ulnar, radial, pectoral, thoracodorsal, long thoracic and lateral thoracic. The muscles innervated by the brachial plexus nerves were the supraspinatus, infraspinatus, subscapularis, teres major, teres minor, deltoid, cleidobrachial, coracobrachialis, biceps brachialis, brachial, triceps brachialis, anconeus, flexor digitorum superficialis, flexor digitorum profundus, flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis, lateral ulnar, extensor carpi obliquus, extensor digitorum, superficial pectoral, deep pectoral, ventral serratus, and external oblique abdominal.

  1. Muscle Cramps

    Science.gov (United States)

    Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They often occur after ... It is a very common muscle problem. Muscle cramps can be caused by nerves that malfunction. Sometimes ...

  2. Procedure Oriented Torsional Anatomy of the Forearm for Spasticity Injection.

    Science.gov (United States)

    Chiou-Tan, Faye; Cianca, John; John, Joslyn; Furr-Stimming, Erin; Pandit, Sindhu; Taber, Katherine H

    2015-01-01

    : This is the second in a series of articles related to the concept of "torsional" anatomy. The objective of this article is to provide musculoskeletal ultrasound (MSKUS) anatomy of the forearm in the position of hemispastic flexion as a reference relevant to needle procedures. The MSKUS images were obtained in a healthy human subject. Marker dots were placed over common injection sites in the forearm for spasticity. The MSKUS probe was centered over each dot to obtain a cross-sectional view. A pair of MSKUS images was recorded for each site: the first in anatomic neutral and second in hemiparetic spastic position. The images were compared side to side. In addition, a video recording was made at each site to track the movement of the muscles and nerves during internal rotation. The pronator teres (PT) rotated medially and the brachialis and biceps tendon rotated in view. In addition, the median nerve became more superficial. The flexor carpi radialis rotated medially and was replaced by PT and the median nerve. The flexor carpi ulnaris and flexor digitorum profundus rotated medially and were replaced by the flexor carpi radialis, PT and median nerve. The flexor digitorum superficialis was replaced by the brachioradialis, extensor carpi radialis brevis, and radial nerve. The brachioradialis was replaced by the extensor carpi radialis brevis and extensor digitorum communis. Intended muscle targets rotate out of view and injection range. These are replaced by other muscles and nerves that could inadvertently be injected. This potentially could result in both increased complications and decreased efficacy of the procedure. It is hoped that this series of images will increase the accuracy and safety of needle placement for spasticity injections in the forearm.

  3. Additional Muscle Slip of Bicipital Aponeurosis and its Anomalous Relationship with the Median Cubital Vein

    Directory of Open Access Journals (Sweden)

    Nandini Bhat

    2017-03-01

    Full Text Available The cubital region of the arm is a common site for recording blood pressure, taking blood for analysis and administering intravenous therapy and blood transfusions. During the routine dissection of a 70-year-old male cadaver at the Kasturba Medical College, Manipal, Karnataka, India, in 2015, it was observed that the aponeurotic insertion of the biceps brachii muscle divided into two slips. The medial slip fused normally with the deep fascia of the forearm, while flexor carpi radialis muscle fibres originated from the lateral slip. There was also a single vein in the forearm, the cephalic vein, which bifurcated to form the median cubital vein and the cephalic vein proper. The median cubital vein, further reinforced by the radial vein, passed deep to the two slips of the bicipital aponeurosis and then continued as the basilic vein. During venepuncture, medical practitioners should be aware of potential cubital fossa variations which could lead to nerve entrapment syndromes.

  4. Reversal of TMS-induced motor twitch by training is associated with a reduction in excitability of the antagonist muscle

    Directory of Open Access Journals (Sweden)

    Fregni Felipe

    2011-08-01

    Full Text Available Abstract Background A single session of isolated repetitive movements of the thumb can alter the response to transcranial magnetic stimulation (TMS, such that the related muscle twitch measured post-training occurs in the trained direction. This response is attributed to transient excitability changes in primary motor cortex (M1 that form the early part of learning. We investigated; (1 whether this phenomenon might occur for movements at the wrist, and (2 how specific TMS activation patterns of opposing muscles underlie the practice-induced change in direction. Methods We used single-pulse suprathreshold TMS over the M1 forearm area, to evoke wrist movements in 20 healthy subjects. We measured the preferential direction of the TMS-induced twitch in both the sagittal and coronal plane using an optical goniometer fixed to the dorsum of the wrist, and recorded electromyographic (EMG activity from the flexor carpi radialis (FCR and extensor carpi radialis (ECR muscles. Subjects performed gentle voluntary movements, in the direction opposite to the initial twitch for 5 minutes at 0.2 Hz. We collected motor evoked potentials (MEPs elicited by TMS at baseline and for 10 minutes after training. Results Repetitive motor training was sufficient for TMS to evoke movements in the practiced direction opposite to the original twitch. For most subjects the effect of the newly-acquired direction was retained for at least 10 minutes before reverting to the original. Importantly, the direction change of the movement was associated with a significant decrease in MEP amplitude of the antagonist to the trained muscle, rather than an increase in MEP amplitude of the trained muscle. Conclusions These results demonstrate for the first time that a TMS-twitch direction change following a simple practice paradigm may result from reduced corticospinal drive to muscles antagonizing the trained direction. Such findings may have implications for training paradigms in

  5. 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.

  6. 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

  7. 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

  8. Muscle pain

    African Journals Online (AJOL)

    Key Summary Points. • Muscle pain, known as myalgia, can be in one targeted area or across many muscles, occurring with overexertion or overuse of these muscles. • Pain can be classified as acute or chronic pain and further categorized as nociceptive or neuropathic. • Causes of muscle pain include stress, physical ...

  9. Muscle fatigue based evaluation of bicycle design.

    Science.gov (United States)

    Balasubramanian, V; Jagannath, M; Adalarasu, K

    2014-03-01

    Bicycling posture leads to considerable discomfort and a variety of chronic injuries. This necessitates a proper bicycle design to avoid injuries and thereby enhance rider comfort. The objective of this study was to investigate the muscle activity during cycling on three different bicycle designs, i.e., rigid frame (RF), suspension (SU) and sports (SP) using surface electromyography (sEMG). Twelve male volunteers participated in this study. sEMG signals were acquired bilaterally from extensor carpi radialis (ECR), trapezius medial (TM), latissimus dorsi medial (LDM) and erector spinae (ES), during 30 min of cycling on each bicycle and after cycling. Time domain (RMS) and frequency domain (MPF) parameters were extracted from acquired sEMG signals. From the sEMG study, it was found that the fatigue in right LDM and ES were significantly (p bicycle. This was corroborated by a psychophysical assessment based on RBG pain scale. The study also showed that there was a significantly lesser fatigue with the SU bicycle than the RF and SP bicycles. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  10. Direct magnetic resonance arthrography of the canine elbow

    Directory of Open Access Journals (Sweden)

    Yauheni Zhalniarovich

    2017-01-01

    Full Text Available This study compares the effects of four dilutions of the gadolinium-containing contrast media (1:100; 1:400; 1:800; 1:1,200 administered to the elbow on the quality of magnetic resonance images. All the examined dilutions had a positive effect on image quality, and 1:800 was regarded as the optimal dilution of gadolinium for viewing the elbow because it imparted good contrast to the joint cavity without obliterating the contours of articular surfaces. Transverse, sagittal, and dorsal low-field magnetic resonance images were obtained in 24 canine cadaver front limbs. The musculus biceps brachii, m. triceps brachii, m. extensor carpi radialis, m. flexor carpi ulnaris, the articular surfaces, the medial coronoid process and the anconeal process of the ulna were well visualized by High Resolution Gradient Echo, XBONE T2 and Spin Echo T1 sequences in the sagittal plane. The biceps brachii, pronator teres, flexor carpi radialis, extensor digitorum communis, extensor carpi radialis, deltoid muscle and the articular surface of the medial condyle of the humerus were very well visualized by 3D SST1 and XBONE T2 sequences in the transverse plane. The triceps brachii muscle, extensor digitorum lateralis muscle, superficial digital flexor, deep digital flexor and the medial condyle of the humerus were very well visualized by the Spin Echo T1 sequence in the dorsal plane. This article describes for the first time the use of the gadolinium contrast agent administered to the canine elbow joint during magnetic resonance modality. Magnetic resonance arthrography can be a helpful visualization technique in treating canine soft tissue elbow injury.

  11. 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.

  12. Electromyographic activity of beating and reaching during simulated boardsailing.

    Science.gov (United States)

    Buchanan, M; Cunningham, P; Dyson, R J; Hurrion, P D

    1996-04-01

    This study examined the responses of six competitive boardsailors (three males, three females) during laboratory-based simulation tasks while the electromyographic activity of up to 13 muscles was recorded. A sailboard, mounted in a steel frame and resting on a waterbed, allowed simulation of roll and pitch movements. Wind force was simulated by attaching the boom to a weight stack with a hydraulically controlled buffered release phase. The progression of the simulation test was controlled by the sailor copying movements on an edited video of each subject boardsailing on the open water. Analysis of individual pumping movements for mean peak percentage of maximal enveloped voluntary contraction (%MEVC) in 'beating' and 'reaching' showed that muscular activity in the arm (flexor carpi ulnaris, extensor carpi radialis and biceps brachii) was greatest (66-94% MEVC), with considerable activity (58-75% MEVC) in the deltoid and trapezius shoulder muscles, but much less activity in the leg muscles (16-40% MEVC). For the combined upper and lower body muscles there was a significant difference (P reflecting the current dynamic nature of the sport.

  13. Extracorporeal Shock Wave Stimulation as Alternative Treatment Modality for Wrist and Fingers Spasticity in Poststroke Patients: A Prospective, Open-Label, Preliminary Clinical Trial

    Directory of Open Access Journals (Sweden)

    Robert Dymarek

    2016-01-01

    Full Text Available Objective. To evaluate the effectiveness of radial shock waves (rESW for wrist and fingers flexors spasticity in stroke patients. Methods. Twenty patients with upper limb muscle spasticity were enrolled in the study and treated with a single session of rESW. The spasticity level of the radio carpal (RC and finger (FF joints was assessed using Modified Ashworth Scale (MAS. The resting bioelectrical activity of the flexor carpi radialis (FCR and flexor carpi ulnaris (FCU was examined using surface electromyography (sEMG. Trophic conditions were measured using infrared thermal (IRT imaging. All measurements were conducted at baseline (t0, immediately after rESW (t1, and 1 (t2 and 24 (t3 hours following rESW. Results. Significant reduction in MAS was observed for the RC joint in t1, as well as for the FF joints in t1, t2, and t3. A significant decrease in sEMG was shown for the FCR muscle in t1 and t2, as well as for the FCU muscle in t1 and t3. Also, a significant increase in IRT value was observed in t3 only. Conclusions. A single session of rESW could be an effective alternative treatment for reduction of limb spasticity and could lead to improvement of trophic conditions of the spastic muscles.

  14. The effect of keyboard key spacing on typing speed, error, usability, and biomechanics: Part 1.

    Science.gov (United States)

    Pereira, Anna; Lee, David L; Sadeeshkumar, Harini; Laroche, Charles; Odell, Dan; Rempel, David

    2013-06-01

    In this study, we evaluated the effects of key spacing on a conventional computer keyboard on typing speed, percentage error, usability, and forearm muscle activity and wrist posture. International standards that specify the spacing between keys on a keyboard have been guided primarily by design convention because few studies have evaluated the effects of key spacing on productivity, usability, and biomechanical factors. Experienced male typists (N = 37) with large fingers (middle finger length > or = 8.7 cm or finger breadth of > or = 2.3 cm) typed on five keyboards that differed only in horizontal and vertical key spacing (19 x 19 mm, 18 x 19 mm, 17 x 19 mm, 16 x 19 mm, and 17 x 17 mm) while typing speed, percentage error, fatigue, preference, extensor carpi ulnaris and flexor carpi ulnaris muscle activity, and wrist extension and ulnar deviation were recorded. Productivity and usability ratings were significantly worse for the keyboard with spacing of 16 x 19 mm compared with the other keyboards. Differences on these measures between the other keyboards were not significant. Muscle activity tended to increase in the left forearm and decrease in the right with decreasing horizontal key spacing. There was also a trend for left wrist extension to increase and left ulnar deviation to decrease with decreasing horizontal key spacing. Reducing vertical key spacing from 19 to 17 mm had no significant effect on productivity or usability ratings. The study findings support key spacing on a computer keyboard between 17 and 19 mm in both vertical and horizontal directions. These findings may influence keyboard standards and the design of keyboards.

  15. Pisiform bursitis: a forgotten pathology.

    Science.gov (United States)

    Draghi, Ferdinando; Gregoli, Bettina; Bortolotto, Chandra

    2014-01-01

    Pisiform bursitis is a disease often forgotten in both everyday practice and medical literature. The pisiform bursa is not constant; when present, it is located between the tendon of the flexor carpi ulnaris and pisiform bone. Bursitis causes pain in the medial side of the wrist and enters into the differential diagnosis of various diseases of this anatomic region, in particular, with enthesitis of the flexor carpi ulnaris and the ganglion of piso-pyramidal compartment. We present the sonographic appearance of pisiform bursitis in a symptomatic patient. © 2014 Wiley Periodicals, Inc.

  16. Distal radioulnar joint: functional anatomy, including pathomechanics.

    Science.gov (United States)

    Haugstvedt, J R; Langer, M F; Berger, R A

    2017-05-01

    The distal radioulnar joint allows the human to rotate the forearm to place the hand in a desired position to perform different tasks, without interfering with the grasping function of the hand. The ulna is the stable part of the forearm around which the radius rotates; the stability of the distal radioulnar joint is provided by the interaction between ligaments, muscles and bones. The stabilizing structures are the triangular fibrocartilage complex, the ulnocarpal ligament complex, the extensor carpi ulnaris tendon and tendon sheath, the pronator quadratus, the interosseous membrane and ligament, the bone itself and the joint capsule. The purpose of this review article is to present and illustrate the current understanding of the functional anatomy and pathomechanics of this joint.

  17. A new method of ergonomic testing of gloves protecting against cuts and stabs during knife use.

    Science.gov (United States)

    Irzmańska, Emilia; Tokarski, Tomasz

    2017-05-01

    The paper presents a new method of ergonomic evaluation of gloves protecting against cuts and stabs during knife use, consisting of five manual dexterity tests. Two of them were selected based on the available literature and relevant safety standards, and three were developed by the authors. All of the tests were designed to simulate occupational tasks associated with meat processing as performed by the gloved hand in actual workplaces. The tests involved the three most common types of protective gloves (knitted gloves made of a coverspun yarn, metal mesh gloves, and metal mesh gloves with an ergonomic polyurethane tightener) and were conducted on a group of 20 males. The loading on the muscles of the upper limb (adductor pollicis, flexor carpi ulnaris, flexor carpi radialis, and biceps brachii) was measured using surface electromyography. For the obtained muscle activity values, correlations were found between the glove type and loading of the upper limb. ANOVA showed that the activity of all muscles differed significantly between the five tests. A relationship between glove types and electromyographic results was confirmed at a significance level of α = 0.05. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Variations in the Anatomical Structures of the Guyon Canal.

    Science.gov (United States)

    Fadel, Zahir T; Samargandi, Osama A; Tang, David T

    2017-05-01

    Compression neuropathy of the ulnar nerve at the Guyon canal is commonly seen by hand surgeons. Different anatomical variations of structures related to the Guyon canal have been reported in the literature. A thorough knowledge of the normal contents and possible variations is essential during surgery and exploration. To review the recognized anatomical variations within and around the Guyon canal. This study is a narrative review in which relevant papers, clinical studies, and anatomical studies were selected by searching electronic databases (PubMed and EMBASE). Extensive manual review of references of the included studies was performed. We also describe a case report of an aberrant muscle crossing the Guyon canal. This study identified several variations in the anatomical structures of the Guyon canal reported in the literature. Variations of the ulnar nerve involved its course, branching pattern, deep motor branch, superficial sensory branch, dorsal cutaneous branch, and the communication with the median nerve. Ulnar artery variations involved its course, branching pattern, the superficial ulnar artery, and the dorsal perforating artery. Aberrant muscles crossing the Guyon canal were found to originate from the antebrachial fascia, pisiform bone, flexor retinaculum, the tendon of palmaris longus, flexor carpi ulnaris, or flexor carpi radialis; these muscles usually fuse with the hypothenar group. The diverse variations of the contents of the Guyon canal were adequately described in the literature. Taking these variations into consideration is important in preventing clinical misinterpretation and avoiding potential surgical complications.

  19. Muscle biopsy.

    Science.gov (United States)

    Meola, G; Bugiardini, E; Cardani, R

    2012-04-01

    Muscle biopsy is required to provide a definitive diagnosis in many neuromuscular disorders. It can be performed through an open or needle technique under local anesthesia. The major limitations of the needle biopsy technique are the sample size, which is smaller than that obtained with open biopsy, and the impossibility of direct visualization of the sampling site. However, needle biopsy is a less invasive procedure than open biopsy and is particularly indicated for diagnosis of neuromuscular disease in infancy and childhood. The biopsied muscle should be one affected by the disease but not be too weak or too atrophic. Usually, in case of proximal muscle involvement, the quadriceps and the biceps are biopsied, while under suspicion of mitochondrial disorder, the deltoid is preferred. The samples must be immediately frozen or fixed after excision to prevent loss of enzymatic reactivity, DNA depletion or RNA degradation. A battery of stainings is performed on muscle sections from every frozen muscle biopsy arriving in the pathology laboratory. Histological, histochemical, and histoenzymatic stainings are performed to evaluate fiber atrophy, morphological, and structural changes and metabolic disorders. Moreover, immunohistochemistry and Western blotting analysis may be used for expression analysis of muscle proteins to obtain a specific diagnosis. There are myopathies that do not need muscle biopsy since a genetic test performed on a blood sample is enough for definitive diagnosis. Muscle biopsy is a useful technique which can make an enormous contribution in the field of neuromuscular disorders but should be considered and interpreted together with the patient's family and clinical history.

  20. Differential partitioning of rumen-protected n-3 and n-6 fatty acids into muscles with different metabolism.

    Science.gov (United States)

    Wolf, C; Ulbrich, S E; Kreuzer, M; Berard, J; Giller, K

    2018-03-01

    Bioavailability of polyunsaturated fatty acids (PUFA) in ruminants is enhanced by their protection from ruminal biohydrogenation. Both n-3 and n-6 PUFA fulfil important physiological functions. We investigated potentially different incorporation patterns of these functional PUFA into three beef muscles with different activity characteristics. We supplemented 33 Angus heifers with rumen-protected oils characterized either by mainly C18:2 n-6 (linoleic acid (LA) in sunflower oil) or by C20:5 (eicosapentaenoic acid (EPA)) and C22:6 (docosahexaenoic acid (DHA)), both prevalent n-3 PUFA in fish oil. Contents and proportions of n-3 and n-6 PUFA of total fatty acids were elevated in the muscles of the respective diet group but they were partitioned differently into the muscles. For EPA and DHA, but not for LA, the diet effect was more distinct in the extensor carpi radialis compared to longissimus thoracis and biceps femoris. Partitioning of PUFA in metabolism could be related to muscle function. This has to be confirmed in other muscles, adipose tissues and organs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Getting Muscles

    Science.gov (United States)

    ... re thinking about aren't possible for kids. Superheroes, of course, aren't real, and professional athletes ... can make you stronger. Why? Because you're using your muscles when you do it. Eat Strong ...

  2. Muscle cramps

    Science.gov (United States)

    ... the lower leg/calf Back of the thigh (hamstrings) Front of the thigh (quadriceps) Cramps in the ... Names Cramps - muscle Images Chest stretch Groin stretch Hamstring stretch Hip stretch Thigh stretch Triceps stretch References ...

  3. The Influence of Robotic Assistance on Reducing Neuromuscular Effort and Fatigue during Extravehicular Activity Glove Use

    Science.gov (United States)

    Madden, Kaci E.; Deshpande, Ashish D.; Peters, Benjamin J.; Rogers, Jonathan M.; Laske, Evan A.; McBryan, Emily R.

    2017-01-01

    The three-layered, pressurized space suit glove worn by Extravehicular Activity (EVA) crew members during missions commonly causes hand and forearm fatigue. The Spacesuit RoboGlove (SSRG), a Phase VI EVA space suit glove modified with robotic grasp-assist capabilities, has been developed to augment grip strength in order to improve endurance and reduce the risk of injury in astronauts. The overall goals of this study were to i) quantify the neuromuscular modulations that occur in response to wearing a conventional Phase VI space suit glove (SSG) during a fatiguing task, and ii) determine the efficacy of Spacesuit RoboGlove (SSRG) in reversing the adverse neuromuscular modulations and restoring altered muscular activity to barehanded levels. Six subjects performed a fatigue sequence consisting of repetitive dynamic-gripping interspersed with isometric grip-holds under three conditions: barehanded, wearing pressurized SSG, and wearing pressurized SSRG. Surface electromyography (sEMG) from six forearm muscles (flexor digitorum superficialis (FDS), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), extensor digitorum (ED), extensor carpi radialis longus (ECRL), and extensor carpi ulnaris (ECU)) and subjective fatigue ratings were collected during each condition. Trends in amplitude and spectral distributions of the sEMG signals were used to derive metrics quantifying neuromuscular effort and fatigue that were compared across the glove conditions. Results showed that by augmenting finger flexion, the SSRG successfully reduced the neuromuscular effort needed to close the fingers of the space suit glove in more than half of subjects during two types of tasks. However, the SSRG required more neuromuscular effort to extend the fingers compared to a conventional SSG in many subjects. Psychologically, the SSRG aided subjects in feeling less fatigued during short periods of intense work compared to the SSG. The results of this study reveal the promise of the SSRG as a

  4. Forearm Flexor Muscles in Children with Cerebral Palsy Are Weak, Thin and Stiff

    Directory of Open Access Journals (Sweden)

    Eva Pontén

    2017-04-01

    Full Text Available Children with cerebral palsy (CP often develop reduced passive range of motion with age. The determining factor underlying this process is believed to be progressive development of contracture in skeletal muscle that likely changes the biomechanics of the joints. Consequently, to identify the underlying mechanisms, we modeled the mechanical characteristics of the forearm flexors acting across the wrist joint. We investigated skeletal muscle strength (Grippit® and passive stiffness and viscosity of the forearm flexors in 15 typically developing (TD children (10 boys/5 girls, mean age 12 years, range 8–18 yrs and nine children with CP Nine children (6 boys/3 girls, mean age 11 ± 3 years (yrs, range 7–15 yrs using the NeuroFlexor® apparatus. The muscle stiffness we estimate and report is the instantaneous mechanical response of the tissue that is independent of reflex activity. Furthermore, we assessed cross-sectional area of the flexor carpi radialis (FCR muscle using ultrasound. Age and body weight did not differ significantly between the two groups. Children with CP had a significantly weaker (−65%, p < 0.01 grip and had smaller cross-sectional area (−43%, p < 0.01 of the FCR muscle. Passive stiffness of the forearm muscles in children with CP was increased 2-fold (p < 0.05 whereas viscosity did not differ significantly between CP and TD children. FCR cross-sectional area correlated to age (R2 = 0.58, p < 0.01, body weight (R2 = 0.92, p < 0.0001 and grip strength (R2 = 0.82, p < 0.0001 in TD children but only to grip strength (R2 = 0.60, p < 0.05 in children with CP. We conclude that children with CP have weaker, thinner, and stiffer forearm flexors as compared to typically developing children.

  5. Presence of Multiple Tendinous Insertions of Palmaris Longus: A ...

    African Journals Online (AJOL)

    Case Details: We report here a unique case of palmaris longus presenting variation distally as its tendon divides to gain multiple attachments with the fascia covering the abductor pollicis brevis, flexor retinaculum and the tendon of flexor carpi ulnaris. In addition, it also continues as palmar aponeurosis as its normal course.

  6. Increased gain of vestibulospinal potentials evoked in neck and leg muscles when standing under height-induced postural threat.

    Science.gov (United States)

    Naranjo, E N; Allum, J H J; Inglis, J T; Carpenter, M G

    2015-05-07

    To measure changes in amplitudes of vestibular evoked myogenic potentials (VEMPs) elicited from neck, upper and lower limb muscles during a quiet standing task with increased postural threat achieved by manipulating surface height. Twenty eight subjects were tested while standing on a platform raised to 0.8 m and 3.2 m from the ground. Surface electromyography was recorded from the ipsilateral sternocleidomastoid (SCM), biceps brachii (BB), flexor carpi radialis (FCR), soleus (SOL) and medial gastrocnemius (MG) muscles. Stimulation was with air-conducted short tone bursts (4 ms). After controlling for background muscle activity, VEMP amplitudes were compared between heights and correlated with changes in state anxiety, fear and arousal. VEMP amplitude significantly increased in SCM (9%) and SOL (12.7%) with increased surface height (pgains. Results demonstrate that VEMPs can be used to test different VSR pathways simultaneously during stance. Since fear and anxiety are prevalent with vestibular disorders, they should be considered as potential contributing factors for clinical vestibular outcome measures. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. 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.

  8. Prolonged relaxation after stimulation of the clasping muscle of male frog, Rana japonica, during the breeding season.

    Science.gov (United States)

    Ishii, Yoshiki; Tsuchiya, Teizo

    2010-07-01

    We investigated the mechanical properties of the flexor carpi radialis muscle (FCR), a forelimb muscle used mainly for amplexus in the breeding season (February to March), of the male Japanese brown frog, Rana japonica. In the present experiment, the changes in force and stiffness of the FCR before, during, and after contraction were measured at 4 degrees C. The total time from the end of stimulation to the end of relaxation was about 30 min. The time course of this prolonged relaxation was fitted by two exponential decay processes. Stiffness decreased during prolonged relaxation, but stayed higher than force, when normalized to peak values. These mechanical properties of the FCR were different from those of the glutaeus magnus muscle (GM) in the hindlimb, used for jumping. When a quick release was applied to the FCR during relaxation, the force recovered gradually after a sudden decrease. The time course of this force recovery was fitted by a single exponential term, and the rate constant decreased as the prolonged relaxation proceeded. The possible involvement of active process(es) in the prolonged relaxation is discussed.

  9. Muscle channelopathies.

    Science.gov (United States)

    Statland, Jeffrey; Phillips, Lauren; Trivedi, Jaya R

    2014-08-01

    Skeletal muscle channelopathies are rare heterogeneous diseases with marked genotypic and phenotypic variability. Despite advances in understanding of the molecular pathology of these disorders, the diverse phenotypic manifestations remain a challenge in diagnosis and therapeutics. These disorders can cause lifetime disability and affect quality of life. There is no treatment of these disorders approved by the US Food and Drug Administration at this time. Recognition and treatment of symptoms might reduce morbidity and improve quality of life. This article summarizes the clinical manifestations, diagnostic studies, pathophysiology, and treatment options in nondystrophic myotonia, congenital myasthenic syndrome, and periodic paralyses. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. The effect of forearm posture on wrist flexion in computer workers with chronic upper extremity musculoskeletal disorders

    Directory of Open Access Journals (Sweden)

    Thompson R Terry

    2008-04-01

    flexion is consistent with known biomechanical changes in the distal extensor carpi ulnaris tendon that occur with forearm supination. We infer from these results that wrist extensor muscle passive tension may be elevated in UEMSD subjects compared to controls, particularly in the extensor carpi ulnaris muscle. Measuring wrist flexion at the supine forearm posture may highlight flexion restrictions that are not otherwise apparent.

  11. Hormonal and neuromuscular responses to mechanical vibration applied to upper extremity muscles.

    Directory of Open Access Journals (Sweden)

    Riccardo Di Giminiani

    Full Text Available OBJECTIVE: To investigate the acute residual hormonal and neuromuscular responses exhibited following a single session of mechanical vibration applied to the upper extremities among different acceleration loads. METHODS: Thirty male students were randomly assigned to a high vibration group (HVG, a low vibration group (LVG, or a control group (CG. A randomized double-blind, controlled-parallel study design was employed. The measurements and interventions were performed at the Laboratory of Biomechanics of the University of L'Aquila. The HVG and LVG participants were exposed to a series of 20 trials ×10 s of synchronous whole-body vibration (WBV with a 10-s pause between each trial and a 4-min pause after the first 10 trials. The CG participants assumed an isometric push-up position without WBV. The outcome measures were growth hormone (GH, testosterone, maximal voluntary isometric contraction during bench-press, maximal voluntary isometric contraction during handgrip, and electromyography root-mean-square (EMGrms muscle activity (pectoralis major [PM], triceps brachii [TB], anterior deltoid [DE], and flexor carpi radialis [FCR]. RESULTS: The GH increased significantly over time only in the HVG (P = 0.003. Additionally, the testosterone levels changed significantly over time in the LVG (P = 0.011 and the HVG (P = 0.001. MVC during bench press decreased significantly in the LVG (P = 0.001 and the HVG (P = 0.002. In the HVG, the EMGrms decreased significantly in the TB (P = 0.006 muscle. In the LVG, the EMGrms decreased significantly in the DE (P = 0.009 and FCR (P = 0.006 muscles. CONCLUSION: Synchronous WBV acutely increased GH and testosterone serum concentrations and decreased the MVC and their respective maximal EMGrms activities, which indicated a possible central fatigue effect. Interestingly, only the GH response was dependent on the acceleration with respect to the subjects' responsiveness.

  12. Imaging of muscle injuries

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, G.Y. [Iowa Univ., Iowa City, IA (United States). Dept. of Radiology; Brandser, E.A. [Iowa Univ., Iowa City, IA (United States). Dept. of Radiology; Kathol, M.H. [Iowa Univ., Iowa City, IA (United States). Dept. of Radiology; Tearse, D.S. [Iowa Univ., Iowa City, IA (United States). Dept. of Orthopaedic Surgery; Callaghan, J.J. [Iowa Univ., Iowa City, IA (United States). Dept. of Orthopaedic Surgery

    1996-01-01

    Although skeletal muscle is the single largest tissue in the body, there is little written about it in the radiologic literature. Indirect muscle injuries, also called strains or tears, are common in athletics, and knowing the morphology and physiology of the muscle-tendon unit is the key to the understanding of these injuries. Eccentric muscle activation produces more tension within the muscle tan when it is activated concentrically, making it more susceptible to tearing. Injuries involving the muscle belly tend to occur near the myotendinous junction. In adolescents, the weakest link in the muscle-tendon-bone complex is the apophysis. Traditionally, plain radiography has been the main diagnostic modality for evaluation of these injuries; however, with the advent of MRI it has become much easier to diagnose injuries primarily affecting the soft tissues. This article reviews the anatomy and physiology of the muscle-tendon unit as they relate to indirect muscle injuries. Examples of common muscle injuries are illustrated. (orig.)

  13. Engineering Skeletal Muscle Repair

    OpenAIRE

    Juhas, Mark; Bursac, Nenad

    2013-01-01

    Healthy skeletal muscle has a remarkable capacity for regeneration. Even at a mature age, muscle tissue can undergo a robust rebuilding process that involves the formation of new muscle cells and extracellular matrix and the re-establishment of vascular and neural networks. Understanding and reverse-engineering components of this process is essential for our ability to restore loss of muscle mass and function in cases where the natural ability of muscle for self-repair is exhausted or impaire...

  14. Dual AAV Gene Therapy for Duchenne Muscular Dystrophy with a 7-kb Mini-Dystrophin Gene in the Canine Model.

    Science.gov (United States)

    Kodippili, Kasun; Hakim, Chady H; Pan, Xiufang; Yang, Hsiao T; Yue, Yongping; Zhang, Yadong; Shin, Jin-Hong; Yang, N Nora; Duan, Dongsheng

    2018-03-01

    Dual adeno-associated virus (AAV) technology was developed in 2000 to double the packaging capacity of the AAV vector. The proof of principle has been demonstrated in various mouse models. Yet, pivotal evidence is lacking in large animal models of human diseases. Here we report expression of a 7-kb canine ΔH2-R15 mini-dystrophin gene using a pair of dual AAV vectors in the canine model of Duchenne muscular dystrophy (DMD). The ΔH2-R15 minigene is by far the most potent synthetic dystrophin gene engineered for DMD gene therapy. We packaged minigene dual vectors in Y731F tyrosine-modified AAV-9 and delivered to the extensor carpi ulnaris muscle of a 12-month-old affected dog at the dose of 2 × 10 13 viral genome particles/vector/muscle. Widespread mini-dystrophin expression was observed 2 months after gene transfer. The missing dystrophin-associated glycoprotein complex was restored. Treatment also reduced muscle degeneration and fibrosis and improved myofiber size distribution. Importantly, dual AAV therapy greatly protected the muscle from eccentric contraction-induced force loss. Our data provide the first clear evidence that dual AAV therapy can be translated to a diseased large mammal. Further development of dual AAV technology may lead to effective therapies for DMD and many other diseases in human patients.

  15. Correlative Evaluation of Mental and Physical Workload of Laparoscopic Surgeons Based on Surface Electromyography and Eye-tracking Signals.

    Science.gov (United States)

    Zhang, Jian-Yang; Liu, Sheng-Lin; Feng, Qing-Min; Gao, Jia-Qi; Zhang, Qiang

    2017-09-11

    Surgeons' mental and physical workloads are major focuses of operating room (OR) ergonomics, and studies on this topic have generally focused on either mental workload or physical workload, ignoring the interaction between them. Previous studies have shown that physically demanding work may affect mental performance and may be accompanied by impaired mental processing and decreased performance. In this study, 14 participants were recruited to perform laparoscopic cholecystectomy (LC) procedures in a virtual simulator. Surface electromyography (sEMG) signals of the bilateral trapezius, bicipital, brachioradialis and flexor carpi ulnaris (FCU) muscles and eye-tracking signals were acquired during the experiment. The results showed that the least square means of muscle activity during the LC phases of surgery in an all-participants mixed effects model were 0.79, 0.81, and 0.98, respectively. The observed muscle activities in the different phases exhibited some similarity, while marked differences were found between the forearm bilateral muscles. Regarding mental workload, significant differences were observed in pupil dilation between the three phases of laparoscopic surgery. The mental and physical workloads of laparoscopic surgeons do not appear to be generally correlated, although a few significant negative correlations were found. This result further indicates that mental fatigue does markedly interfere with surgeons' operating movements.

  16. Decremental responses to repetitive nerve stimulation in x-linked bulbospinal muscular atrophy.

    Science.gov (United States)

    Kim, Jee Young; Park, Kee Duk; Kim, Seung-Min; Sunwoo, Il Nam

    2013-01-01

    X-linked bulbospinal muscular atrophy (X-BSMA) is characterized by bulbar and spinal muscular weakness and fasciculations. Although X-BSMA is a motor neuronopathy, there are several reports of myasthenic symptoms or decremental responses to repetitive nerve stimulation (RNS). We report the results of applying the RNS test to 15 patients among 41 with genetically confirmed X-BSMA; these 15 patients complained of fatigue, ease of becoming tired, or early muscular exhaustion. The 3-Hz RNS test was performed on the trapezius, nasalis, orbicularis oculi, flexor carpi ulnaris, and abductor digiti quinti muscles. A decrement greater than 10% was considered abnormal. Additionally, a pharmacologic response to neostigmine was identified in three patients. A significant decrement was observed in 67% of patients, and was most common in the trapezius muscle (nine cases). The decrement of the trapezius muscle response ranged from 15.9% to 36.9%. The decrement was inversely correlated with the amplitude of compound muscle action potentials at rest. Neostigmine injection markedly improved the decrement in three patients, who showed noticeable decremental responses to 3-Hz RNS. This study shows that myasthenic symptoms and abnormal decremental responses to low-rate RNS are common in X-BSMA.

  17. The anatomy and ontogeny of the head, neck, pectoral, and upper limb muscles of Lemur catta and Propithecus coquereli (primates): discussion on the parallelism between ontogeny and phylogeny and implications for evolutionary and developmental biology.

    Science.gov (United States)

    Diogo, Rui; Molnar, Julia L; Smith, Timothy D

    2014-08-01

    Most anatomical studies of primates focus on skeletal tissues, but muscular anatomy can provide valuable information about phylogeny, functional specializations, and evolution. Herein, we present the first detailed description of the head, neck, pectoral, and upper limb muscles of the fetal lemuriforms Lemur catta (Lemuridae) and Propithecus coquereli (Indriidae). These two species belong to the suborder Strepsirrhini, which is often presumed to possess some plesiomorphic anatomical features within primates. We compare the muscular anatomy of the fetuses with that of infants and adults and discuss the evolutionary and developmental implications. The fetal anatomy reflects a phylogenetically more plesiomorphic condition in nine of the muscles we studied and a more derived condition in only two, supporting a parallel between ontogeny and phylogeny. The derived exceptions concern muscles with additional insertions in the fetus which are lost in adults of the same species, that is, flexor carpi radialis inserts on metacarpal III and levator claviculae inserts on the clavicle. Interestingly, these two muscles are involved in movements of the pectoral girdle and upper limb, which are mainly important for activities in later stages of life, such as locomotion and prey capture, rather than activities in fetal life. Accordingly, our findings suggest that some exceptions to the "ontogeny parallels phylogeny" rule are probably driven more by ontogenetic constraints than by adaptive plasticity. © 2014 Wiley Periodicals, Inc.

  18. Assessment of Myoelectric Controller Performance and Kinematic Behavior of a Novel Soft Synergy-Inspired Robotic Hand for Prosthetic Applications.

    Science.gov (United States)

    Fani, Simone; Bianchi, Matteo; Jain, Sonal; Pimenta Neto, José Simões; Boege, Scott; Grioli, Giorgio; Bicchi, Antonio; Santello, Marco

    2016-01-01

    Myoelectric artificial limbs can significantly advance the state of the art in prosthetics, since they can be used to control mechatronic devices through muscular activity in a way that mimics how the subjects used to activate their muscles before limb loss. However, surveys indicate that dissatisfaction with the functionality of terminal devices underlies the widespread abandonment of prostheses. We believe that one key factor to improve acceptability of prosthetic devices is to attain human likeness of prosthesis movements, a goal which is being pursued by research on social and human-robot interactions. Therefore, to reduce early abandonment of terminal devices, we propose that controllers should be designed so as to ensure effective task accomplishment in a natural fashion. In this work, we have analyzed and compared the performance of three types of myoelectric controller algorithms based on surface electromyography to control an underactuated and multi-degrees of freedom prosthetic hand, the SoftHand Pro. The goal of the present study was to identify the myoelectric algorithm that best mimics the native hand movements. As a preliminary step, we first quantified the repeatability of the SoftHand Pro finger movements and identified the electromyographic recording sites for able-bodied individuals with the highest signal-to-noise ratio from two pairs of muscles, i.e., flexor digitorum superficialis/extensor digitorum communis, and flexor carpi radialis/extensor carpi ulnaris. Able-bodied volunteers were then asked to execute reach-to-grasp movements, while electromyography signals were recorded from flexor digitorum superficialis/extensor digitorum communis as this was identified as the muscle pair characterized by high signal-to-noise ratio and intuitive control. Subsequently, we tested three myoelectric controllers that mapped electromyography signals to position of the SoftHand Pro. We found that a differential electromyography-to-position mapping ensured the

  19. Short-term effect of local muscle vibration treatment versus sham therapy on upper limb in chronic post-stroke patients: a randomized controlled trial.

    Science.gov (United States)

    Costantino, Cosimo; Galuppo, Laura; Romiti, Davide

    2017-02-01

    In recent years, local muscle vibration received considerable attention as a useful method for muscle stimulation in clinical therapy. Some studies described specific vibration training protocol, and few of them were conducted on post-stroke patients. Therefore there is a general uncertainty regarding the vibrations protocol. The aim of this study was to evaluate the effects of local muscle high frequency mechano-acoustic vibratory treatment on grip muscle strength, muscle tonus, disability and pain in post-stroke individuals with upper limb spasticity. Single-blind randomized controlled trial. Outpatient rehabilitation center. Thirty-two chronic poststroke patients with upper-limb spasticity: 21 males, 11 females, mean age 61.59 years ±15.50, time passed from stroke 37.78±17.72 months. The protocol treatment consisted of the application of local muscle vibration, set to a frequency of 300 Hz, for 30 minutes 3 times per week, for 12 sessions, applied to the skin covering the venter of triceps brachii and extensor carpi radialis longus and brevis muscles during voluntary isometric contraction. All participants were randomized in two groups: group A treated with vibration protocol; group B with sham therapy. All participants were evaluated before and after 4-week treatment with Hand Grip Strength Test, Modified Ashworth Scale, QuickDASH score, FIM scale, Fugl-Meyer Assessment, Jebsen-Taylor Hand Function Test and Verbal Numerical Rating Scale of pain. Outcomes between groups was compared using a repeated-measures ANOVA. Over 4 weeks, the values recorded in group A when compared to group B demonstrated statistically significant improvement in grip muscle strength, pain and quality of life and decrease of spasticity; P-values were <0.05 in all tested parameters. Rehabilitation treatment with local muscle high frequency (300 Hz) vibration for 30 minutes, 3 times a week for 4 weeks, could significantly improve muscle strength and decrease muscle tonus, disability and

  20. Healthy Muscles Matter

    Science.gov (United States)

    ... do. Exercising, getting enough rest, and eating a balanced diet will help to keep your muscles healthy for ... keep your muscles in good health. Eating a balanced diet will help manage your weight and provide a ...

  1. Obturator internus muscle strains

    Directory of Open Access Journals (Sweden)

    Caoimhe Byrne, MB BCh, BAO

    2017-03-01

    Full Text Available We report 2 cases of obturator internus muscle strains. The injuries occurred in young male athletes involved in kicking sports. Case 1 details an acute obturator internus muscle strain with associated adductor longus strain. Case 2 details an overuse injury of the bilateral obturator internus muscles. In each case, magnetic resonance imaging played a crucial role in accurate diagnosis.

  2. the sternalis muscle

    African Journals Online (AJOL)

    2009-08-17

    Aug 17, 2009 ... scan of the chest wall was performed to gain clarity of the mam- mographic findings (Figs 1a, 1b and 2). The CT scan demonstrated a flattened band of muscle density lying anterior to the medial margin of the pectoralis muscle. This structure was separated from the underlying pectoralis muscle by a thin ...

  3. Lipolysis in Skeletal Muscle

    DEFF Research Database (Denmark)

    Serup, Annette Karen Lundbeck

    of AMPK in regulation of lipid handling and lipolysis in the basal non-contracting state and during muscle contractions in skeletal muscle. To evaluate the role of AMPK, we measured protein expression and phosphorylation as well as gene expression of proteins important for regulation of lipid handling...... and lipolysis in skeletal muscle from wildtype mice and mice overexpressing a kinase dead AMPKα2 construct (AMPKα2 KD) in the basal non-contracting state and during in situ stimulated muscle contractions. We found, that IMTG levels were ~50% lower in AMPKα2 KD in the basal resting state, explained by a lower....... IMTG was in wildtype mice reduced with ~50% after muscle contractions with no effect of contractions in AMPKα2 KD mice. Concomitantly, ATGL was phosphorylated at ser406 and HSL on ser565 with muscle contractions in an AMPK dependent manner, suggesting that these sites actives lipolysis during muscle...

  4. Wrist ultrasound examination – scanning technique and ultrasound anatomy. Part 2: Ventral wrist

    Directory of Open Access Journals (Sweden)

    Cyprian Olchowy

    2017-06-01

    Full Text Available Ultrasound imaging of the musculoskeletal system is an important element of the diagnostic and therapeutic protocol. Clinical decisions, including those regarding surgical procedures, are often based solely on ultrasound imaging. However, detailed knowledge on the anatomy and a correct scanning technique are crucial for an accurate diagnosis. Modern ultrasonographic equipment allows obtaining detailed anatomical images of muscle tendons, ligaments, nerves and vessels of the carpal area. Ventral wrist ultrasound is one of the most common diagnostic procedures in patients with suspected carpal tunnel syndrome. Ventral wrist evaluation is also often performed in patients with wrist pain of unclear etiology, rheumatic diseases, wrist injuries or symptoms of ulnar neuropathy. The aim of this paper is to present ultrasound images with corresponding anatomical schemes. The technique of ultrasound examination of the ventral wrist along with practical guidance to help obtain highly diagnostic images is also discussed. The present paper is the second part of an article devoted to ultrasound anatomy and wrist ultrasound technique – the part discussing the dorsal side of the wrist was published in the Journal of Ultrasonography, Vol. 15, No 61. The following anatomical structures should be visualized during an ultrasound examination of the ventral wrist, both in the carpal tunnel as well as proximally and distally to it: four flexor digitorum superficialis tendons, four flexor digitorum profundus tendons, flexor pollicis longus, flexor carpi radialis tendon, median nerve and flexor retinaculum; in the carpal tunnel as well as proximally and distally to it: the ulnar nerve, ulnar artery and veins; the tendon of the flexor carpi ulnaris muscle; carpal joints.

  5. A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

    Directory of Open Access Journals (Sweden)

    Matthew Emerson Randolph

    2015-10-01

    Full Text Available 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, 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 muscular dystrophies. The biology of muscle stem cells varies depending on their embryologic origins and 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.

  6. 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

  7. Motor branches of the ulnar nerve to the forearm: an anatomical study and guidelines for selective neurectomy.

    Science.gov (United States)

    Paulos, Renata; Leclercq, Caroline

    2015-11-01

    Precise knowledge of motor nerve branches is critical to plan selective neurectomies for the treatment of spastic limbs. Our objective is to describe the muscular branching pattern of the ulnar nerve in the forearm and suggest an ideal surgical approach for selective neurectomy of the flexor carpi ulnaris. The ulnar nerve was dissected under loop magnification in 20 upper limbs of fresh frozen cadavers and its branches to the flexor carpi ulnaris muscle (FCU) and to the flexor digitorum profundus muscle (FDP) were quantified. We measured their diameter, length and distance between their origin and the medial epicondyle. The point where the ulnar artery joined the nerve was observed. The position in which the ulnar nerve gave off each branch was noted (ulnar, posterior or radial) and the Martin-Gruber connection, when present, had its origin observed and its diameter measured. The ulnar nerve gave off two to five muscular branches, among which, one to four to the FCU and one or two to the FDP. In all cases, the first branch was to the FCU. It arose on average 1.4 cm distal to the epicondyle, but in four specimens it arose above or at the level of the medial epicondyle (2.0 cm above in one case, 1.5 cm above in two cases, and at the level of the medial epicondyle in one). The first branch to the FDP arose on average 5.0 cm distal to the medial epicondyle. All the branches to FDP but one arose from the radial aspect of the ulnar nerve. A Martin-Gruber connection was present in nine cases. All motor branches arose in the proximal half of the forearm and the ulnar nerve did not give off branches distal to the point where it was joined by the ulnar artery. The number of motor branches of the ulnar nerve to the FCU varies from 2 to 4. An ideal approach for selective neurectomy of the FCU should start 4 cm above the medial epicondyle, and extend distally to 50% of the length of the forearm or just to the point where the ulnar artery joins the nerve.

  8. The hamstring muscle complex.

    Science.gov (United States)

    van der Made, A D; Wieldraaijer, T; Kerkhoffs, G M; Kleipool, R P; Engebretsen, L; van Dijk, C N; Golanó, P

    2015-07-01

    The anatomical appearance of the hamstring muscle complex was studied to provide hypotheses for the hamstring injury pattern and to provide reference values of origin dimensions, muscle length, tendon length, musculotendinous junction (MTJ) length as well as width and length of a tendinous inscription in the semitendinosus muscle known as the raphe. Fifty-six hamstring muscle groups were dissected in prone position from 29 human cadaveric specimens with a median age of 71.5 (range 45-98). Data pertaining to origin dimensions, muscle length, tendon length, MTJ length and length as well as width of the raphe were collected. Besides these data, we also encountered interesting findings that might lead to a better understanding of the hamstring injury pattern. These include overlapping proximal and distal tendons of both the long head of the biceps femoris muscle and the semimembranosus muscle (SM), a twist in the proximal SM tendon and a tendinous inscription (raphe) in the semitendinosus muscle present in 96 % of specimens. No obvious hypothesis can be provided purely based on either muscle length, tendon length or MTJ length. However, it is possible that overlapping proximal and distal tendons as well as muscle architecture leading to a resultant force not in line with the tendon predispose to muscle injury, whereas the presence of a raphe might plays a role in protecting the muscle against gross injury. Apart from these architectural characteristics that may contribute to a better understanding of the hamstring injury pattern, the provided reference values complement current knowledge on surgically relevant hamstring anatomy. IV.

  9. MUSCLE INJURIES IN ATHLETES.

    Science.gov (United States)

    Barroso, Guilherme Campos; Thiele, Edilson Schwansee

    2011-01-01

    This article had the aim of demonstrating the physiology, diagnosis and treatment of muscle injuries, focusing on athletes and their demands and expectations. Muscle injuries are among the most common complaints in orthopedic practice, occurring both among athletes and among non-athletes. These injuries present a challenge for specialists, due to the slow recovery, during which time athletes are unable to take part in training and competitions, and due to frequent sequelae and recurrences of the injuries. Most muscle injuries (between 10% and 55% of all injuries) occur during sports activities. The muscles most commonly affected are the ischiotibial, quadriceps and gastrocnemius. These muscles go across two joints and are more subject to acceleration and deceleration forces. The treatment for muscle injuries varies from conservative treatment to surgery. New procedures are being used, like the hyperbaric chamber and the use of growth factors. However, there is still a high rate of injury recurrence. Muscle injury continues to be a topic of much controversy. New treatments are being researched and developed, but prevention through muscle strengthening, stretching exercises and muscle balance continues to be the best "treatment".

  10. An artificial muscle computer

    Science.gov (United States)

    Marc O'Brien, Benjamin; Alexander Anderson, Iain

    2013-03-01

    We have built an artificial muscle computer based on Wolfram's "2, 3" Turing machine architecture, the simplest known universal Turing machine. Our computer uses artificial muscles for its instruction set, output buffers, and memory write and addressing mechanisms. The computer is very slow and large (0.15 Hz, ˜1 m3); however by using only 13 artificial muscle relays, it is capable of solving any computable problem given sufficient memory, time, and reliability. The development of this computer shows that artificial muscles can think—paving the way for soft robots with reflexes like those seen in nature.

  11. Accessory piriformis muscle

    Directory of Open Access Journals (Sweden)

    Sedat Develi

    2017-03-01

    Full Text Available Piriformis muscle originates from facies pelvica of sacrum and inserts on the trochanter major. It is one of the lateral rotator muscles of the hip and a landmark point in the gluteal region since n. ischiadicus descends to the thigh by passing close to the muscle. This contiguity may be associated with the irritation of the nerve which is known as piriformis syndrome. A rare anatomic variation of the muscle which observed on 74 years old male cadaver is discussed in this case report. [Cukurova Med J 2017; 42(1.000: 182-183

  12. Guyon tunnel syndrome secondary to excessive healing tissue in a child: a case report

    Directory of Open Access Journals (Sweden)

    Sevinç Teoman

    2008-05-01

    Full Text Available Abstract We describe a case of an 8-year-old boy who developed a combined motor and sensory neuropathy of the distal ulnar nerve, after sustaining a superficial injury to the right flexor carpi ulnaris tendon at the level of the distal wrist crease. Guyon's canal syndrome is a very rare entity during childhood. We have noted only one prior description of this syndrome in the pediatric age group in a review of the English literature.

  13. Triquetral fracture with associated pisiform subluxation

    OpenAIRE

    Gan, Lee Ping; Satkunanantham, Mala; Sreedharan, Sechachalam; Chew, Winston Yoon Chong

    2015-01-01

    We herein present a case of right triquetral fracture with associated pisiform and flexor carpi ulnaris subluxation in a 29-year-old man. Initial radiography showed a right triquetral fracture. Computed tomography and magnetic resonance imaging demonstrated a triquetral fracture with a subluxated pisiform. Open reduction and lag screw fixation of the right triquetrum was performed, with good subsequent recovery of function. Although triquetral fracture with subluxation of the pisotriquetral j...

  14. Functional anatomy of the lateral collateral ligament of the elbow.

    Science.gov (United States)

    Hackl, M; Bercher, M; Wegmann, K; Müller, L P; Dargel, J

    2016-07-01

    The aim of this study was to analyze the functional anatomy of the lateral collateral ligament complex (LCLC) and the surrounding forearm extensors. Using 81 human cadaveric upper extremities, the anatomy of the forearm extensors-especially the anconeus, supinator and extensor carpi ulnaris (ECU)-was analyzed. After removal of aforementioned extensors the functional anatomy of the LCLC was analyzed. The origin of the LCLC was evaluated for isometry. The insertion types of the lateral ulnar collateral ligament (LUCL) were analyzed and classified. The ECU runs parallel to the RCL to dynamically preserve varus stability. The supinator and anconeus muscle fibers coalesce with the LCLC and lengthen during pronation. The anconeus fibers run parallel to the LUCL in full flexion. The LCLC consists of the annular ligament (AL) and the isometric radial collateral ligament (RCL). During elbow flexion, its posterior branches (LUCL) tighten while the anterior branches loosen. When performing a pivot shift test, the loosened LUCL fibers do not fully tighten in full extension. The LUCL inserts along with the AL at the supinator crest. Three different insertion types could be observed. The LUCL represents the posterior branch of the RCL rather than a distinct ligament. It is non-isometric and lengthens during elbow flexion. The RCL was found to be of vital importance for neutralization of posterolateral rotatory forces. Pronation of the forearm actively stabilizes the elbow joint as the supinator, anconeus and biceps muscle work in unison to increase posterolateral rotatory stability.

  15. One-handed load carrying--cardiovascular, muscular and subjective indices of endurance and fatigue.

    Science.gov (United States)

    Kilbom, A; Hägg, G M; Käll, C

    1992-01-01

    A group of 5 women and 11 men walked on a treadmill, each carrying a weight in the right hand. In separate experiments, the mass was varied to give total exhaustion within 3 min, 5 min, 9 min, and 13 min. In additional experiments 50% and 25% of the masses leading to exhaustion after 5 min were used, and these were stopped after 16 min. Heart rate (fc) and systolic blood pressure (BPs) were measured noninvasively. There was a consistent increase in fc x BPs during the experiments leading to exhaustion, while steady-states were obtained in the nonexhausting trials. An electromyogram (EMG) was recorded with cutaneous electrodes over the flexor carpi ulnaris and flexor digitorum superficialis muscles and the number of zero crossings (ZC) of the EMG signal per time unit were analysed. As the subjects approached exhaustion, the number of ZC declined exponentially, reaching approximately 50% of their initial values. In the nonexhausting experiments, however, the decline was slower and less marked, and during the second half of the experiment the number of ZC increased again. Subjectively, endurance was underestimated by all the subjects. It was concluded that cardiovascular and muscle criteria of fatigue in carrying coincided. Prolonged carrying in one hand of more than 6 kg or 10 kg for young healthy women and men respectively should not be recommended, since it could lead to cardiovascular non steady-states and EMG signs of fatigue.

  16. Topographic anatomy of the ulnar tunnel.

    Science.gov (United States)

    Gil, Young-Chun; Shin, Kang-Jae; Lee, Ju-Young; Hu, Kyung-Seok; Kim, Hee-Jin; Song, Wu-Chul; Koh, Ki-Seok

    2015-09-01

    The aim of this study was to clarify the definition of the anterior wall of the ulnar tunnel and to reveal the topographical characteristics of the various components of the ulnar tunnel. Twenty-two forearms from 11 embalmed cadavers (7 males, 4 females; mean age, 67.8 years) were carefully dissected. In all cases, the anterior wall of the ulnar tunnel comprised the hypothenar fascia, which originated from the tendon of the flexor carpi ulnaris muscle. The palmar carpal ligament, the distal extent of the antebrachial fascia, was located deep to the anterior wall and formed only the anterior boundary of the proximal hiatus of the ulnar tunnel. The hypothenar fascia was attached to the flexor retinaculum at 15.2 mm lateral to the pisiform bone. However, the palmar carpal ligament was attached to the flexor retinaculum just lateral to the ulnar artery; the distance between the attachment of the palmar carpal ligament and the pisiform bone was 8.7 mm. Anatomical variations potentially associated with ulnar nerve compression were observed. The accessory abductor digiti minimi muscle and the fibrous band crossing the ulnar nerve in the ulnar tunnel were found in 27 and 23 % of forearms, respectively. A more detailed description of the anterior wall of the ulnar tunnel than was previously available is presented herein, and topographic and metric data regarding each structure of the tunnel are reported.

  17. Development of a Compact Wireless Laplacian Electrode Module for Electromyograms and Its Human Interface Applications

    Directory of Open Access Journals (Sweden)

    Akira Ichikawa

    2013-02-01

    Full Text Available In this study, we developed a compact wireless Laplacian electrode module for electromyograms (EMGs. One of the advantages of the Laplacian electrode configuration is that EMGs obtained with it are expected to be sensitive to the firing of the muscle directly beneath the measurement site. The performance of the developed electrode module was investigated in two human interface applications: character-input interface and detection of finger movement during finger Braille typing. In the former application, the electrode module was combined with an EMG-mouse click converter circuit. In the latter, four electrode modules were used for detection of finger movements during finger Braille typing. Investigation on the character-input interface indicated that characters could be input stably by contraction of (a the masseter, (b trapezius, (c anterior tibialis and (d flexor carpi ulnaris muscles. This wide applicability is desirable when the interface is applied to persons with physical disabilities because the disability differs one to another. The investigation also demonstrated that the electrode module can work properly without any skin preparation. Finger movement detection experiments showed that each finger movement was more clearly detectable when comparing to EMGs recorded with conventional electrodes, suggesting that the Laplacian electrode module is more suitable for detecting the timing of finger movement during typing. This could be because the Laplacian configuration enables us to record EMGs just beneath the electrode. These results demonstrate the advantages of the Laplacian electrode module.

  18. Intra-rater reliability of ultrasound imaging of wrist extensor muscles in patients with tetraplegia.

    Science.gov (United States)

    Gorgey, Ashraf S; Timmons, Mark K; Michener, Lori A; Ericksen, Jeffery J; Gater, David R

    2014-02-01

    (i) To determine the intra-rater reliability and precision of the ultrasound cross-sectional area (CSA) measurements of the wrist extensors in individuals with spinal cord injury (SCI), and (ii) to determine whether tetraplegia has a negative influence on the reliability and precision for these measurements. A repeated-measures cross-sectional study. Clinical hospital and academic settings. The study was conducted with 20 men with SCI (9 paraplegia and 11 tetraplegia) and 10 able-bodied controls. Ultrasound images were captured of the right side extensor carpi radialis-longus (ECRL) and the extensor digitorum communis (EDC) were captured in 2 sessions separated by 48-72 hours. The intraclass correlation coefficients for the CSA measurements of the ECRL and EDC muscles were greater than 0.87 for all 3 groups. The standard error of the measure (SEM) ranged from 0.11-0.22 cm(2) for the ECRL and 0.13-0.27 cm(2) for the EDC. The minimal detectable change of ECL ranged from 0.16 to 0.31 cm(2) and of EDC from 0.19 to 0.38 cm(2). The group differences in muscle CSA of both muscles were found; these differences were greater than the calculated minimal detectable changes. The intraclass correlation coefficients were lower and the SEMs and minimal detectable changes were higher for the group with tetraplegia compared with the able-bodied controls and the group with paraplegia. This study documented substantial intra-rater reliability of measurements of the ECRL and ECD CSA by using ultrasound images, which support the use of this technique to effectively evaluate the musculoskeletal changes after SCI and during rehabilitation. Skeletal muscle atrophy in persons with tetraplegia might have a negative influence on the reliability and precision of these CSA measurements; however, these differences in reliability and precision are not of clinical significance. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights

  19. Physical Rehabilitation Improves Muscle Function Following Volumetric Muscle Loss Injury

    Science.gov (United States)

    2014-12-19

    muscle , but it did so without significant morphological adaptations (e.g., no hypertrophy and hyperplasia). Wheel running up-regulated metabolic genes...been shown to foster regeneration of injured muscle [5,32,33] and promote hypertrophy (i.e., increased protein synthesis or muscle weight) in muscle ...remaining muscle tissue. Strengthening of synergist muscles can partially compensate for the loss of function due to VML injury. Compensatory hypertrophy

  20. Muscles, exercise and obesity

    DEFF Research Database (Denmark)

    Pedersen, Bente K; Febbraio, Mark A

    2012-01-01

    of yet unidentified factors, secreted from muscle cells, which may influence cancer cell growth and pancreas function. Many proteins produced by skeletal muscle are dependent upon contraction; therefore, physical inactivity probably leads to an altered myokine response, which could provide a potential...

  1. Proteomics of Skeletal Muscle

    DEFF Research Database (Denmark)

    Deshmukh, Atul

    2016-01-01

    Skeletal muscle is the largest tissue in the human body and plays an important role in locomotion and whole body metabolism. It accounts for ~80% of insulin stimulated glucose disposal. Skeletal muscle insulin resistance, a primary feature of Type 2 diabetes, is caused by a decreased ability of m...

  2. The hamstring muscle complex

    NARCIS (Netherlands)

    van der Made, A. D.; Wieldraaijer, T.; Kerkhoffs, G. M.; Kleipool, R. P.; Engebretsen, L.; van Dijk, C. N.; Golanó, P.

    2015-01-01

    The anatomical appearance of the hamstring muscle complex was studied to provide hypotheses for the hamstring injury pattern and to provide reference values of origin dimensions, muscle length, tendon length, musculotendinous junction (MTJ) length as well as width and length of a tendinous

  3. Muscle phosphorylase kinase deficiency

    DEFF Research Database (Denmark)

    Preisler, N; Orngreen, M C; Echaniz-Laguna, A

    2012-01-01

    To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD).......To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD)....

  4. [Diabetic muscle infarction].

    Science.gov (United States)

    ter Bals, Edske; van der Woude, Henk-Jan; Smets, Yves F C

    2013-01-01

    Diabetic muscle infarction is a rare complication of diabetes mellitus that typically presents in the thigh; microvascular abnormalities may play a role. A 32-year-old female presented at the outpatient clinic with a painful, swollen thigh. She had suffered from type 1 diabetes for 22 years. The patient was admitted to the nephrology ward for further evaluation. Deep-venous thrombosis and abscess were excluded with echography. After additional investigations - MRI and a biopsy of skin, muscle and fascia - the diagnosis diabetic muscle infarction was made. The patient was treated with bed rest and analgesics. With hindsight, the muscle biopsy was not actually required in reaching a diagnosis. The diagnosis 'diabetic muscle infarction' is made on the basis of clinical presentation in combination with MRI findings. The treatment consists of bed rest and analgesics.

  5. Biomechanic comparison of 3 tendon transfers for supination of the forearm.

    Science.gov (United States)

    Cheema, Tahseen A; Firoozbakhsh, Keikhosrow; De Carvalho, Alex F; Mercer, Deana

    2006-12-01

    Flexion-pronation of the hand and the forearm is a common deformity when the upper extremity is affected by cerebral palsy. Solutions used to improve the pronation deformity and increase supination include transfer of the flexor carpi ulnaris to the extensor carpi radialis brevis, pronator teres rerouting, and brachioradialis rerouting. The purpose of this study was to compare the biomechanic efficacy of these 3 tendon transfers in simulated supination in cadaveric forearms. Ten fresh-frozen adult cadaveric above-elbow upper extremities were used. In each specimen the 3 tendon transfers were performed sequentially in random order and were loaded in increments of 4 N (1 lb) to a maximum of 36 N (8 lb). Measurements were recorded from the starting point of 90 degrees of pronation. Statistical analysis of the data included the Student t test with the Bonferoni correction. For all transfers, supination increased in a nonlinear manner as the load was increased in a nonlinear manner. For the flexor carpi ulnaris transfer, the forearm reached its neutral position at a load of 9 N (2 lb). The forearm continued to rotate to up to 84 degrees of supination with 36 N (8 lb) of load. With the brachioradialis transfer, the forearm reached its neutral position at 13 N (3 lb) of load and continued to rotate to up to 33 degrees of supination with 36 N of load. With the pronator teres transfer, the forearm never reached the neutral position. Under a maximum load of 36 N, only 55 degrees of rotation from full pronation was obtained. Transfer of the flexor carpi ulnaris to the extensor carpi radialis brevis proved to be the most effective transfer for producing supination in cadavers. The brachioradialis transfer was second best. The pronator teres rerouting was the least effective transfer in effecting simulated supination in this experiment.

  6. Greater bilateral deficit in leg press than in handgrip exercise might be linked to differences in postural stability requirements.

    Science.gov (United States)

    Magnus, Charlene R A; Farthing, Jonathan P

    2008-12-01

    Bilateral deficit is defined as the difference in the summed force between contracting muscles alone and contracting contralateral homologous muscles in combination. The purpose of the study was to investigate how postural stability influences bilateral deficit by comparing an exercise requiring more postural stability (the leg press) with an exercise requiring less postural stability (the handgrip). Eight participants volunteered for the study (3 males, 5 females). Maximal strength was determined by a 1-repetition maximum for the leg press (weight machine) and handgrip (dynamometer) exercises. Electromyography was used to measure activation of the effectors (flexor carpi ulnaris for the handgrip and vastus lateralis for the leg press) and the core muscles (rectus abdominis and external obliques). Bilateral deficit was greater in the leg press (-12.08 +/- 10.22%) than the handgrip (-0.677 +/- 5.00%; p < 0.05). Muscle activation of the effectors and core muscles was not significantly different between unilateral and bilateral conditions for either exercise. However, core muscle activation was significantly greater during the leg press (48.30 +/- 19.60 microV) than during the handgrip (16.50 +/- 8.10 microV; p < 0.05) exercise. These results support the hypothesis that an exercise requiring more postural stability (e.g., the leg press) will have a larger deficit and greater activation of core muscles than an exercise requiring less postural stability (e.g., the handgrip). Since the bilateral deficit was only apparent for the leg press exercise, we conclude that postural stability requirements might influence the magnitude of bilateral deficit.

  7. A muscle model for hybrid muscle activation

    Directory of Open Access Journals (Sweden)

    Klauer Christian

    2015-09-01

    Full Text Available To develop model-based control strategies for Functional Electrical Stimulation (FES in order to support weak voluntary muscle contractions, a hybrid model for describing joint motions induced by concurrent voluntary-and FES induced muscle activation is proposed. It is based on a Hammerstein model – as commonly used in feedback controlled FES – and exemplarily applied to describe the shoulder abduction joint angle. Main component of a Hammerstein muscle model is usually a static input nonlinearity depending on the stimulation intensity. To additionally incorporate voluntary contributions, we extended the static non-linearity by a second input describing the intensity of the voluntary contribution that is estimated by electromyography (EMG measurements – even during active FES. An Artificial Neural Network (ANN is used to describe the static input non-linearity. The output of the ANN drives a second-order linear dynamical system that describes the combined muscle activation and joint angle dynamics. The tunable parameters are adapted to the individual subject by a system identification approach using previously recorded I/O-data. The model has been validated in two healthy subjects yielding RMS values for the joint angle error of 3.56° and 3.44°, respectively.

  8. Evaluation of the effect of a laparoscopic robotized needle holder on ergonomics and skills.

    Science.gov (United States)

    Bensignor, Thierry; Morel, Guillaume; Reversat, David; Fuks, David; Gayet, Brice

    2016-02-01

    Laparoscopy generates technical and ergonomics difficulties due to limited degrees of freedom (DOF) of forceps. To reduce this limitation, a new 5-mm robotized needle holder with two intracorporeal DOF, Jaimy(®), has been developed. The aim of this study was to evaluate its effects on ergonomics and skills. Fourteen surgeons including eight senior and six residents were crossover randomized and stratified based on experience. Three suturing tasks were performed with both Jaimy(®) and a classic needle holder (NH): task 1: Peg-Board; task 2: hexagonal suture; task 3: frontal suture. Postural ergonomics of the dominant arm were evaluated with an ergonomics score (RULA score) thanks to motion capture, and muscular ergonomics with electromyography of six muscular groups (flexor and extensor carpis, biceps, triceps, deltoid, trapeze). Performance outcomes are a quantitative and qualitative score, and skills outcomes are the measurement of the number of movements and the path length travelled by the instrument. The RULA score showed a statistically improved posture with Jaimy(®) (p < 0.001). The cumulative muscular workload (CMW) of four muscles was not different. However, the CMW was in favor of the NH for the flexor carpi ulnaris (p < 0.001) and the triceps (p = 0.027). The number of movements was not different (p = 0.39) although the path length was shorter with Jaimy(®) (p = 0.012). The score for task 1 was in favor of the NH (p = 0.006) with a higher quantity score. Task 2 score was not different (p = 0.086): The quality part of the score was in favor of Jaimy(®) (p = 0.009) and the quantity part was higher with the NH (p = 0.04). The score for task 3 was higher with Jaimy(®) (p = 0.001). This study suggests that the use of a robotized needle holder improves both posture and the quality of laparoscopic sutures.

  9. Respiratory Muscle Plasticity

    Science.gov (United States)

    Gransee, Heather M.; Mantilla, Carlos B.; Sieck, Gary C.

    2014-01-01

    Muscle plasticity is defined as the ability of a given muscle to alter its structural and functional properties in accordance with the environmental conditions imposed on it. As such, respiratory muscle is in a constant state of remodeling, and the basis of muscle’s plasticity is its ability to change protein expression and resultant protein balance in response to varying environmental conditions. Here, we will describe the changes of respiratory muscle imposed by extrinsic changes in mechanical load, activity, and innervation. Although there is a large body of literature on the structural and functional plasticity of respiratory muscles, we are only beginning to understand the molecular-scale protein changes that contribute to protein balance. We will give an overview of key mechanisms regulating protein synthesis and protein degradation, as well as the complex interactions between them. We suggest future application of a systems biology approach that would develop a mathematical model of protein balance and greatly improve treatments in a variety of clinical settings related to maintaining both muscle mass and optimal contractile function of respiratory muscles. PMID:23798306

  10. 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…

  11. 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.

  12. Muscle Disorders - Multiple Languages

    Science.gov (United States)

    ... Health Information Translations Spanish (español) Expand Section Muscle Disorders: MedlinePlus Health Topic - English ... Health Information Translations Characters not displaying correctly on this page? See language display issues . Return to the MedlinePlus Health Information ...

  13. Neurogenic muscle cramps.

    Science.gov (United States)

    Katzberg, Hans D

    2015-08-01

    Muscle cramps are sustained, painful contractions of muscle and are prevalent in patients with and without medical conditions. The objective of this review is to present updates on the mechanism, investigation and treatment of neurogenic muscle cramps. PubMed and Embase databases were queried between January 1980 and July 2014 for English-language human studies. The American Academy of Neurology classification of studies (classes I-IV) was used to assess levels of evidence. Mechanical disruption, ephaptic transmission, disruption of sensory afferents and persistent inward currents have been implicated in the pathogenesis of neurogenic cramps. Investigations are directed toward identifying physiological triggers or medical conditions predisposing to cramps. Although cramps can be self-limiting, disabling or sustained muscle cramps should prompt investigation for underlying medical conditions. Lifestyle modifications, treatment of underlying conditions, stretching, B-complex vitamins, diltiezam, mexiletine, carbamazepine, tetrahydrocannabinoid, leveteracitam and quinine sulfate have shown evidence for treatment.

  14. Human airway smooth muscle

    NARCIS (Netherlands)

    J.C. de Jongste (Johan)

    1987-01-01

    textabstractThe function of airway smooth muscle in normal subjects is not evident. Possible physiological roles include maintenance of optimal regional ventilation/perfusion ratios, reduction of anatomic dead space, stabilisation of cartilaginous bronchi, defense against impurities and, less

  15. Water and Muscle Contraction

    Directory of Open Access Journals (Sweden)

    Enrico Grazi

    2008-08-01

    Full Text Available The interaction between water and the protein of the contractile machinery as well as the tendency of these proteins to form geometrically ordered structures provide a link between water and muscle contraction. Protein osmotic pressure is strictly related to the chemical potential of the contractile proteins, to the stiffness of muscle structures and to the viscosity of the sliding of the thin over the thick filaments. Muscle power output and the steady rate of contraction are linked by modulating a single parameter, a viscosity coefficient. Muscle operation is characterized by working strokes of much shorter length and much quicker than in the classical model. As a consequence the force delivered and the stiffness attained by attached cross-bridges is much larger than usually believed.

  16. Muscle glycogenolysis during exercise

    DEFF Research Database (Denmark)

    Richter, Erik; Ruderman, N B; Gavras, H

    1982-01-01

    glycogenolysis during exercise: contractions principally stimulate glycogenolysis early in exercise, and a direct effect of epinephrine on muscle is needed for continued glycogenolysis. In addition, epinephrine increased oxygen consumption and glucose uptake in both resting and electrically stimulated...

  17. Pneumatic Muscle Actuator Control

    National Research Council Canada - National Science Library

    Lilly, John

    2000-01-01

    This research is relevant to the Air Fore mission because pneumatic muscle actuation devices arc advantageous for certain types of robotics as well as for strength and/or mobility assistance for humans...

  18. Human airway smooth muscle

    OpenAIRE

    Jongste, Johan

    1987-01-01

    textabstractThe function of airway smooth muscle in normal subjects is not evident. Possible physiological roles include maintenance of optimal regional ventilation/perfusion ratios, reduction of anatomic dead space, stabilisation of cartilaginous bronchi, defense against impurities and, less likely, squeezing mucus out of mucous glands and pulling open the alveoli next to the airways1 . Any role of airway smooth muscle is necessarily limited, because an important degree of contraction will l...

  19. Muscle Strength and Poststroke Hemiplegia

    DEFF Research Database (Denmark)

    Kristensen, Otto H; Stenager, Egon; Dalgas, Ulrik

    2017-01-01

    OBJECTIVES: To systematically review (1) psychometric properties of criterion isokinetic dynamometry testing of muscle strength in persons with poststroke hemiplegia (PPSH); and (2) literature that compares muscle strength in patients poststroke with that in healthy controls assessed by criterion...... test in persons with stroke, generally showing marked reductions in muscle strength of paretic and, to a lesser degree, nonparetic muscles when compared with healthy controls, independent of muscle group, contraction mode, and contraction velocity....

  20. 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

  1. Clarification of Eponymous Anatomical Terminology: Structures Named After Dr Geoffrey V. Osborne That Compress the Ulnar Nerve at the Elbow.

    Science.gov (United States)

    Wali, Arvin R; Gabel, Brandon; Mitwalli, Madhawi; Tubbs, R Shane; Brown, Justin M

    2017-05-01

    In 1957, Dr Geoffrey Osborne described a structure between the medial epicondyle and the olecranon that placed excessive pressure on the ulnar nerve. Three terms associated with such structures have emerged: Osborne's band, Osborne's ligament, and Osborne's fascia. As anatomical language moves away from eponymous terminology for descriptive, consistent nomenclature, we find discrepancies in the use of anatomic terms. This review clarifies the definitions of the above 3 terms. We conducted an extensive electronic search via PubMed and Google Scholar to identify key anatomical and surgical texts that describe ulnar nerve compression at the elbow. We searched the following terms separately and in combination: "Osborne's band," "Osborne's ligament," and "Osborne's fascia." A total of 36 papers were included from 1957 to 2016. Osborne's band, Osborne's ligament, and Osborne's fascia were found to inconsistently describe the etiology of ulnar neuritis, referring either to the connective tissue between the 2 heads of the flexor carpi ulnaris muscle as described by Dr Osborne or to the anatomically distinct fibrous tissue between the olecranon process of the ulna and the medial epicondyle of the humerus. The use of eponymous terms to describe ulnar pathology of the elbow remains common, and although these terms allude to the rich history of surgical anatomy, these nonspecific descriptions lead to inconsistencies. As Osborne's band, Osborne's ligament, and Osborne's fascia are not used consistently across the literature, this research demonstrates the need for improved terminology to provide reliable interpretation of these terms among surgeons.

  2. Surgical management of medial humeral epicondylitis, cubital synovial osteochondromatosis and humeroradial subluxation in a cat

    Directory of Open Access Journals (Sweden)

    Karen L Perry

    2017-02-01

    Full Text Available Case summary A 13-year-old domestic shorthair cat presented for evaluation of pain and difficulty ambulating. Orthopedic examination and CT facilitated a diagnosis of bilateral elbow synovial osteochondromatosis with medial humeral epicondylitis and concurrent osteoarthritis. Right humeroradial subluxation was evident on CT images, but no instability was evident preoperatively. Surgical treatment was elected, including external neurolysis of the ulnar nerve, removal of the areas of mineralization within the flexor carpi ulnaris muscle and medial arthrotomy to remove intra-articular mineralized bodies. Following closure, instability of the right elbow was noted with humeroradial subluxation necessitating placement of circumferential suture prostheses to provide satisfactory stability. Reassessment was performed 2, 6, 12, 24 and 40 weeks postoperatively and revealed maintenance of elbow stability and substantial improvement in mobility and comfort. Relevance and novel information While humeroradial subluxation has been reported in association with medial humeral epicondylitis on post-mortem examination, associated clinically significant instability has not been documented previously. Surgeons should be aware of the potential for this complication and check elbow stability following surgery. Despite this complication, a favorable medium-term outcome was achieved for this cat.

  3. Muscle as a secretory organ

    DEFF Research Database (Denmark)

    Pedersen, Bente K

    2013-01-01

    Skeletal muscle is the largest organ in the body. Skeletal muscles are primarily characterized by their mechanical activity required for posture, movement, and breathing, which depends on muscle fiber contractions. However, skeletal muscle is not just a component in our locomotor system. Recent...... evidence has identified skeletal muscle as a secretory organ. We have suggested that cytokines and other peptides that are produced, expressed, and released by muscle fibers and exert either autocrine, paracrine, or endocrine effects should be classified as "myokines." The muscle secretome consists...... of several hundred secreted peptides. This finding provides a conceptual basis and a whole new paradigm for understanding how muscles communicate with other organs such as adipose tissue, liver, pancreas, bones, and brain. In addition, several myokines exert their effects within the muscle itself. Many...

  4. Hydraulically actuated artificial muscles

    Science.gov (United States)

    Meller, M. A.; Tiwari, R.; Wajcs, K. B.; Moses, C.; Reveles, I.; Garcia, E.

    2012-04-01

    Hydraulic Artificial Muscles (HAMs) consisting of a polymer tube constrained by a nylon mesh are presented in this paper. Despite the actuation mechanism being similar to its popular counterpart, which are pneumatically actuated (PAM), HAMs have not been studied in depth. HAMs offer the advantage of compliance, large force to weight ratio, low maintenance, and low cost over traditional hydraulic cylinders. Muscle characterization for isometric and isobaric tests are discussed and compared to PAMs. A model incorporating the effect of mesh angle and friction have also been developed. In addition, differential swelling of the muscle on actuation has also been included in the model. An application of lab fabricated HAMs for a meso-scale robotic system is also presented.

  5. Foot muscles strengthener

    Directory of Open Access Journals (Sweden)

    Boris T. Glavač

    2012-04-01

    Full Text Available Previous experience in the correction of flat feet consisted of the use of insoles for shoes and exercises with toys, balls, rollers, inclined planes, etc. A device for strengthening foot muscles is designed for the correction of flat feet in children and, as its name suggests, for strengthening foot muscles in adults. The device is made of wood and metal, with a mechanism and technical solutions, enabling the implementation of specific exercises to activate muscles responsible for the formation of the foot arch. It is suitable for home use with controlled load quantities since it has calibrated springs. The device is patented with the Intellectual Property Office, Republic of Serbia, as a petty patent.

  6. CREB is activated by muscle injury and promotes muscle regeneration.

    Science.gov (United States)

    Stewart, Randi; Flechner, Lawrence; Montminy, Marc; Berdeaux, Rebecca

    2011-01-01

    The cAMP response element binding protein (CREB) plays key roles in differentiation of embryonic skeletal muscle progenitors and survival of adult skeletal muscle. However, little is known about the physiologic signals that activate CREB in normal muscle. Here we show that CREB phosphorylation and target genes are induced after acute muscle injury and during regeneration due to genetic mutation. Activated CREB localizes to both myogenic precursor cells and newly regenerating myofibers within regenerating areas. Moreover, we found that signals from damaged skeletal muscle tissue induce CREB phosphorylation and target gene expression in primary mouse myoblasts. An activated CREB mutant (CREBY134F) potentiates myoblast proliferation as well as expression of early myogenic transcription factors in cultured primary myocytes. Consistently, activated CREB-YF promotes myoblast proliferation after acute muscle injury in vivo and enhances muscle regeneration in dystrophic mdx mice. Our findings reveal a new physiologic function for CREB in contributing to skeletal muscle regeneration.

  7. Rectus abdominis muscle endometriosis

    International Nuclear Information System (INIS)

    Goker, A.

    2014-01-01

    Endometriosis is characterized by an abnormal existence of functional endometrial tissue outside the uterine cavity, typically occuring within the pelvis of women in reproductive age. We report two cases with endometriosis of the abdominal wall; the first one in the rectus abdominis muscle and the second one in the surgical scar of previous caesarean incision along with the rectus abdominis muscle. Pre-operative evaluation included magnetic resonance imaging. The masses were dissected free from the surrounding tissue and excised with clear margins. Diagnosis of the excised lesions were verified by histopathology. (author)

  8. 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)

  9. 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.

  10. 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

  11. 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

  12. Pelvic floor muscle training exercises

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003975.htm Pelvic floor muscle training exercises To use the sharing features on this page, please enable JavaScript. Pelvic floor muscle training exercises are a series of exercises ...

  13. MRI appearance of muscle denervation

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, S. [University Hospital of Wales, Department of Radiology, Cardiff (United Kingdom); Venkatanarasimha, N.; Walsh, M.A.; Hughes, P.M. [Derriford Hospital, Department of Radiology, Plymouth (United Kingdom)

    2008-05-15

    Muscle denervation results from a variety of causes including trauma, neoplasia, neuropathies, infections, autoimmune processes and vasculitis. Traditionally, the diagnosis of muscle denervation was based on clinical examination and electromyography. Magnetic resonance imaging (MRI) offers a distinct advantage over electromyography, not only in diagnosing muscle denervation, but also in determining its aetiology. MRI demonstrates characteristic signal intensity patterns depending on the stage of muscle denervation. The acute and subacutely denervated muscle shows a high signal intensity pattern on fluid sensitive sequences and normal signal intensity on T1-weighted MRI images. In chronic denervation, muscle atrophy and fatty infiltration demonstrate high signal changes on T1-weighted sequences in association with volume loss. The purpose of this review is to summarise the MRI appearance of denervated muscle, with special emphasis on the signal intensity patterns in acute and subacute muscle denervation. (orig.)

  14. Muscle contraction and force

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline; Risbo, Jens; Pierzynowski, Stefan G.

    2008-01-01

    of nutrient delivery and waste product removal, but are also tethered to surrounding fibres by collagen "wires". This paper therefore addresses aspects of the ancillary network of skeletal muscle at both a microscopic and functional level in order to better understand its role holistically as a considerable...

  15. Making more heart muscle

    NARCIS (Netherlands)

    van den Hoff, Maurice J. B.; Kruithof, Boudewijn P. T.; Moorman, Antoon F. M.

    2004-01-01

    Postnatally, heart muscle cells almost completely lose their ability to divide, which makes their loss after trauma irreversible. Potential repair by cell grafting or mobilizing endogenous cells is of particular interest for possible treatments for heart disease, where the poor capacity for

  16. Muscles and their myokines

    DEFF Research Database (Denmark)

    Pedersen, Bente Klarlund

    2011-01-01

    that a physically active life plays an independent role in the protection against type 2 diabetes, cardiovascular diseases, cancer, dementia and even depression. For most of the last century, researchers sought a link between muscle contraction and humoral changes in the form of an 'exercise factor', which could......In the past, the role of physical activity as a life-style modulating factor has been considered as that of a tool to balance energy intake. Although it is important to avoid obesity, physical inactivity should be discussed in a much broader context. There is accumulating epidemiological evidence......-like fashion, exerting specific endocrine effects on other organs. Other myokines work via paracrine mechanisms, exerting local effects on signalling pathways involved in muscle metabolism. It has been suggested that myokines may contribute to exercise-induced protection against several chronic diseases....

  17. [Primary muscle cramps].

    Science.gov (United States)

    Serratrice, G

    2008-05-01

    Primary muscle cramps, without known cause, are very frequent especially in the elderly and during the night. They are different from secondary cramps. Likewise they are to be separated from several syndromes erroneously quoted as cramps. The pathophysiological mechanism seems due to result from an initial dysfunction in the distal part of the motoneuron. When the cramps are severe, differential diagnosis with amyotrophic lateral sclerosis may be difficult. Quinine is the best empiric treatment largely used in spite of moderate side effects.

  18. MUSCLE TENSION DYSPHONIA

    Directory of Open Access Journals (Sweden)

    Irena Hočevar Boltežar

    2004-07-01

    Full Text Available Background. Muscle tension dysphonia (MTD is the cause of hoarseness in almost one half of the patients with voice disorders. The otorhinolaryngologic examination discovers no evident organic lesions in the larynx at least in the beginning of the voice problems. The reason for the hoarse voice is a disordered and maladjusted activity of the muscles taking part in phonation and/or articulation. In some patients, the irregular function of the larynx results in mucosal lesions on vocal folds. The factors participating in the development of MTD, directly or indirectly influence the quality of laryngeal mucosa, the activity of the phonatory muscles and/or increase of the vocal load. In the diagnostics and treatment of the MTD a phoniatrician, a speech and language therapist and a psychologist closely cooperate with the patient who must take an active role. The treatment is a long-lasting one but resulted in a high percentage of clinical success.Conclusions. Most likely, MTD is not a special disease but only a reflection of any disorder in the complicated system of regulation and realization of phonation. The prognosis of treatment is good when all unfavourable factors participating in development of MTD are eliminated and a proper professional voice- and psychotherapy started.

  19. Dismorfia muscular Muscle dysmorphia

    Directory of Open Access Journals (Sweden)

    Sheila Seleri Marques Assunção

    2002-12-01

    Full Text Available Preocupações mórbidas com a imagem corporal eram tidas até recentemente como problemas eminentemente femininos. Atualmente estas preocupações também têm sido encontradas no sexo masculino. A dismorfia muscular é um subtipo do transtorno dismórfico corporal que ocorre principalmente em homens que, apesar da grande hipertrofia muscular, consideram-se pequenos e fracos. Além de estar associada a prejuízos sociais, ocupacionais, recreativos e em outras áreas do funcionamento do indivíduo, a dismorfia muscular é também um fator de risco para o abuso de esteróides anabolizantes. Este artigo aborda aspectos epidemiológicos, etiológicos e padrões clínicos da dismorfia muscular, além de tecer comentários sobre estratégias de tratamento para este transtorno.Morbid concern over body image was considered, until recently, a female issue. Nowadays, it has been viewed as a common male disorder. Muscle dysmorphia, a subtype of a body dysmorphic disorder, affects men who, despite having clear muscular hypertroph,y see themselves as frail and small. Besides being associated to major social, leisure and occupational dysfunction, muscle dysmorphia is also a risk factor for the abuse of steroids. This article describes epidemiological, etiological and clinical characteristics of muscle dysmorphia and comments on its treatment strategy.

  20. Activation of respiratory muscles during respiratory muscle training.

    Science.gov (United States)

    Walterspacher, Stephan; Pietsch, Fabian; Walker, David Johannes; Röcker, Kai; Kabitz, Hans-Joachim

    2018-01-01

    It is unknown which respiratory muscles are mainly activated by respiratory muscle training. This study evaluated Inspiratory Pressure Threshold Loading (IPTL), Inspiratory Flow Resistive Loading (IFRL) and Voluntary Isocapnic Hyperpnea (VIH) with regard to electromyographic (EMG) activation of the sternocleidomastoid muscle (SCM), parasternal muscles (PARA) and the diaphragm (DIA) in randomized order. Surface EMG were analyzed at the end of each training session and normalized using the peak EMG recorded during maximum inspiratory maneuvers (Sniff nasal pressure: SnPna, maximal inspiratory mouth occlusion pressure: PImax). 41 healthy participants were included. Maximal activation was achieved for SCM by SnPna; the PImax activated predominantly PARA and DIA. Activations of SCM and PARA were higher in IPTL and VIH than for IFRL (pVIH (pVIH differ in activation of inspiratory respiratory muscles. Whereas all methods mainly stimulate accessory respiratory muscles, diaphragm activation was predominant in IPTL. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Reinnervation of Paralyzed Muscle by Nerve Muscle Endplate Band Grafting

    Science.gov (United States)

    2016-10-01

    x 3 mm), a nerve branch, intramuscular nerve terminals, and a motor endplate (MEP) band with numerous neuromuscular junctions. The superficial ...when muscle was stretched at optimal tension of 0.8 N. Maximal muscle force was calculated as average muscle contraction to 5 stimulation currents...force during the 200-millisecond contraction was identified, as well as initial passive tension before stimulation. The difference between themaximal

  2. Nuclear Positioning in Muscle Development and Disease

    OpenAIRE

    Eric eFolker; Mary eBaylies

    2013-01-01

    Muscle disease as a group is characterized by muscle weakness, muscle loss, and impaired muscle function. Although the phenotype is the same, the underlying cellular pathologies, and the molecular causes of these pathologies, are diverse. One common feature of many muscle disorders is the mispositioning of myonuclei. In unaffected individuals myonuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, th...

  3. Pneumatic Artificial Muscles Based on Biomechanical Characteristics of Human Muscles

    Directory of Open Access Journals (Sweden)

    N. Saga

    2006-01-01

    Full Text Available This article reports the pneumatic artificial muscles based on biomechanical characteristics of human muscles. A wearable device and a rehabilitation robot that assist a human muscle should have characteristics similar to those of human muscle. In addition, since the wearable device and the rehabilitation robot should be light, an actuator with a high power to weight ratio is needed. At present, the McKibben type is widely used as an artificial muscle, but in fact its physical model is highly nonlinear. Therefore, an artificial muscle actuator has been developed in which high-strength carbon fibres have been built into the silicone tube. However, its contraction rate is smaller than the actual biological muscles. On the other hand, if an artificial muscle that contracts axially is installed in a robot as compactly as the robot hand, big installing space is required. Therefore, an artificial muscle with a high contraction rate and a tendon-driven system as a compact actuator were developed, respectively. In this study, we report on the basic structure and basic characteristics of two types of actuators.

  4. Transplantation of Devitalized Muscle Scaffolds is Insufficient for Appreciable De Novo Muscle Fiber Regeneration After Volumetric Muscle Loss Injury

    Science.gov (United States)

    2014-10-10

    minced muscle grafts were shown to support de novo skeletal muscle regeneration. For instance, devitalized whole extensor digitorum longus (EDL) muscle...antero- lateral aspect of the ankle, and the distal EDL muscle tendon and extensor hallicus longus (EHL) muscle was isolated and severed above the

  5. Exercising with blocked muscle glycogenolysis

    DEFF Research Database (Denmark)

    Nielsen, Tue L; Pinós, Tomàs; Brull, Astrid

    2018-01-01

    of expression and activation of proteins involved in glycolytic flux revealed that in glycolytic, but not oxidative muscle from exercised McArdle mice, the glycolytic flux had changed compared to that in wild-type mice. Specifically, exercise triggered in glycolytic muscle a differentiated activation of insulin......BACKGROUND: McArdle disease (glycogen storage disease type V) is an inborn error of skeletal muscle metabolism, which affects glycogen phosphorylase (myophosphorylase) activity leading to an inability to break down glycogen. Patients with McArdle disease are exercise intolerant, as muscle glycogen......-derived glucose is unavailable during exercise. Metabolic adaptation to blocked muscle glycogenolysis occurs at rest in the McArdle mouse model, but only in highly glycolytic muscle. However, it is unknown what compensatory metabolic adaptations occur during exercise in McArdle disease. METHODS: In this study, 8...

  6. Muscle strength in myasthenia gravis

    DEFF Research Database (Denmark)

    Cejvanovic, S; Vissing, J

    2014-01-01

    is related to disease duration or gender. The aim of this study was to quantify the strength of patients with MG and investigate whether it is related to disease duration. METHODS: Eight muscle groups were tested by manual muscle testing and with a hand-held dynamometer in 38 patients with generalized MG...... and 37 healthy age- and gender-matched controls. The disease duration was recorded and compared with strength measures. RESULTS: On average, muscle strength was decreased by 28% compared with controls (Pstrength measures in individual patients did not differ, suggesting that the muscle...... force reported was not subject to fatigue, but reflected fixed weakness. The male patients showed a greater reduction in muscle force in all eight muscle groups than women with MG (60% vs 77% of normal, Pstrength in shoulder abductors was most affected (51% vs 62...

  7. PDH regulation in skeletal muscle

    DEFF Research Database (Denmark)

    Kiilerich, Kristian

    is determined by the overall content / activity of the regulatory proteins PDH kinase (PDK), of which there are 4 isoforms, and PDH phosphatase (PDP), of which there are 2 isoforms. The overall aim of the PhD project was to elucidate 4 issues. 1: Role of muscle type in resting and exercise-induced PDH...... in arm than leg muscles during exercise in humans may be the result of lower PDH-E1? content and not a muscle type dependent difference in PDH regulation. Both low muscle glycogen and increased plasma FFA are associated with upregulation of PDK4 protein and less exercise-induced increase in PDHa activity...... in human skeletal muscle. It may be noted that the increased PDK4 protein associated with elevated plasma FFA occurs already 2 hours after different dietary intake. A week of physical inactivity (bed rest), leading to whole body glucose intolerance, does not affect muscle PDH-E1? content, or the exercise...

  8. Unorthodox angiogenesis in skeletal muscle.

    Science.gov (United States)

    Egginton, S; Zhou, A L; Brown, M D; Hudlická, O

    2001-02-16

    The morphological pattern of angiogenesis occurring in mature, differentiated skeletal muscle in response to chronically increased muscle blood flow, muscle stretch or repetitious muscle contractions was examined to determine (a) whether capillary neoformation follows the generally accepted temporal paradigm, and (b) how the growth pattern is influenced by mechanical stimuli. Adult rats were treated for a maximum of 14 days either with the vasodilator prazosin, to elevate skeletal muscle blood flow, or underwent surgical removal of one ankle flexor, to induce compensatory overload in the remaining muscles, or had muscles chronically stimulated by implanted electrodes. Extensor digitorum longus and/or extensor hallucis proprius muscles were removed at intervals and processed for electron microscopy. A systematic examination of capillaries and their ultrastructure characterised the sequence of morphological changes indicative of angiogenesis, i.e., basement membrane disruption, endothelial cell (EC) sprouting and proliferation [immunogold labelling after bromodeoxyuridine (BrdU) incorporation]. Capillary growth in response to increased blood flow occurred by luminal division without sprouting or basement membrane (BM) breakage. In stretched muscles, EC proliferation and abluminal sprouting gave rise to new capillaries, with BM loss only at sprout tips. These distinct mechanisms appear to be additive as in chronically stimulated muscles (increased blood flow with repetitive stretch and shortening during muscle contractions) both forms of capillary growth occurred. Endothelial cell numbers per capillary profile, mitotic EC nuclei, and BrdU labelling confirmed cell proliferation prior to overt angiogenesis. Physiological angiogenesis within adult skeletal muscle progresses by mechanisms that do not readily conform to the consensus view of capillary growth, derived mainly from observations made during development, pathological vessel growth, or from in vitro systems. The

  9. Immunology Guides Skeletal Muscle Regeneration

    OpenAIRE

    F. Andrea Sass; Michael Fuchs; Matthias Pumberger; Sven Geissler; Georg N. Duda; Carsten Perka; Katharina Schmidt-Bleek

    2018-01-01

    Soft tissue trauma of skeletal muscle is one of the most common side effects in surgery. Muscle injuries are not only caused by accident-related injuries but can also be of an iatrogenic nature as they occur during surgical interventions when the anatomical region of interest is exposed. If the extent of trauma surpasses the intrinsic regenerative capacities, signs of fatty degeneration and formation of fibrotic scar tissue can occur, and, consequentially, muscle function deteriorates or is d...

  10. Muscle necrosis - computer tomography aspects

    International Nuclear Information System (INIS)

    Franze, I.; Goebel, N.; Stuckmann, G.

    1985-01-01

    In four patients muscle necroses were observed. In two patients these were caused by intraoperative positioning, in one by having worked with a pneumatic hammer and in one possibly by alcohol. CT showed hypodense areas in the affected muscles which were - in the state of subacute necroses - surrounded by hyperaemic borders. The diagnosis was confirmed by puncture or biopsy. After six months hypodense areas were still perceptible in the atrophic muscles of two patients. (orig.) [de

  11. Muscle dysmorphia: current insights

    Directory of Open Access Journals (Sweden)

    Tod D

    2016-08-01

    Full Text Available David Tod1 Christian Edwards2 Ieuan Cranswick1 1School of Sport and Exercise Science, Faculty of Science, Liverpool John Moores University, Liverpool, Merseyside, 2Institute of Sport and Exercise Science, University of Worcester, Worcester, Worcestershire, UK Abstract: Since 1997, there has been increasing research focusing on muscle dysmorphia, a condition underpinned by people’s beliefs that they have insufficient muscularity, in both the Western and non-Western medical and scientific communities. Much of this empirical interest has surveyed nonclinical samples, and there is limited understanding of people with the condition beyond knowledge about their characteristics. Much of the existing knowledge about people with the condition is unsurprising and inherent in the definition of the disorder, such as dissatisfaction with muscularity and adherence to muscle-building activities. Only recently have investigators started to explore questions beyond these limited tautological findings that may give rise to substantial knowledge advances, such as the examination of masculine and feminine norms. There is limited understanding of additional topics such as etiology, prevalence, nosology, prognosis, and treatment. Further, the evidence is largely based on a small number of unstandardized case reports and descriptive studies (involving small samples, which are largely confined to Western (North American, British, and Australian males. Although much research has been undertaken since the term “muscle dysmorphia” entered the psychiatric lexicon in 1997, there remains tremendous scope for knowledge advancement. A primary task in the short term is for investigators to examine the extent to which the condition exists among well-defined populations to help determine the justification for research funding relative to other public health issues. A greater variety of research questions and designs may contribute to a broader and more robust knowledge base

  12. Muscle damage and muscle remodeling: no pain, no gain?

    Science.gov (United States)

    Flann, Kyle L; LaStayo, Paul C; McClain, Donald A; Hazel, Mark; Lindstedt, Stan L

    2011-02-15

    Skeletal muscle is a dynamic tissue that responds adaptively to both the nature and intensity of muscle use. This phenotypic plasticity ensures that muscle structure is linked to patterns of muscle use throughout the lifetime of an animal. The cascade of events that result in muscle restructuring - for example, in response to resistance exercise training - is often thought to be initiated by muscle damage. We designed this study to test the hypothesis that symptomatic (i.e. detectable) damage is a necessary precursor for muscle remodeling. Subjects were divided into two experimental populations: pre-trained (PT) and naive (NA). Demonstrable muscle damage was avoided in the PT group by a three-week gradual 'ramp-up' protocol. By contrast, the NA group was subjected to an initial damaging bout of exercise. Both groups participated in an eight-week high-force eccentric-cycle ergometry program (20 min, three times per week) designed to equate the total work done during training between the groups. The NA group experienced signs of damage, absent in the PT group, as indicated by greater than five times higher levels of plasma creatine kinase (CK) and self-reporting of initial perceived soreness and exertion, yet muscle size and strength gains were not different for the two groups. RT-PCR analysis revealed similar increases in levels of the growth factor IGF-1Ea mRNA in both groups. Likewise, the significant (Pmuscle volume) were equal in both groups. Finally, strength increases were identical for both groups (PT=25% and NA=26% improvement). The results of this study suggest that muscle rebuilding - for example, hypertrophy - can be initiated independent of any discernible damage to the muscle.

  13. Turning scar into muscle.

    Science.gov (United States)

    de Carvalho, Antonio Carlos Campos; Carvalho, Adriana Bastos

    2012-09-26

    After the demonstration that somatic cells could be reprogrammed to a pluripotent state, exciting new prospects were opened for the cardiac regeneration field. It did not take long for the development of strategies to convert somatic cells directly into cardiomyocytes. Despite the intrinsic difficulties of cell reprogramming, such as low efficiency, the therapeutic possibilities created by the ability to turn scar into muscle are enormous. Here, we discuss some of the major advances and strategies used in direct cardiac reprogramming and examine discrepancies and concerns that still need to be resolved in the field.

  14. Contractures and muscle disease.

    Science.gov (United States)

    Walters, R Jon

    2016-08-01

    Contractures are one of a handful of signs in muscle disease, besides weakness and its distribution, whose presence can help guide us diagnostically, a welcome star on the horizon. Contractures are associated with several myopathies, some with important cardiac manifestations, and consequently are important to recognise; their presence may also provide us with a potential satisfying 'penny dropping' diagnostic moment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. Lipoxygenase in chicken muscle

    International Nuclear Information System (INIS)

    Grossman, S.; Bergman, M.; Sklan, D.

    1988-01-01

    The presence of lipoxygenase-type enzymes was demonstrated in chick muscles. Examination of the oxidation products of [ 14 C]arachidonic acid revealed the presence of 15-lipoxygenase. The enzyme was partially purified by affinity chromatography on linoleoyl-aminoethyl-Sepharose. The enzyme was stable on frozen storage, and activity was almost completely preserved after 12-month storage at -20 degree C. During this period the content of cis,cis-1,4-pentadiene fatty acids decreased slightly. It is suggested that lipoxygenase may be responsible for some of the oxidative changes occurring in fatty acids on frozen storage of chicken meat

  16. Human skeletal muscle fibroblasts stimulate in vitro myogenesis and in vivo muscle regeneration

    DEFF Research Database (Denmark)

    Mackey, Abigail L.; Magnan, Mélanie; Chazaud, Bénédicte

    2017-01-01

    Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. In addition to the indispensable role satellite cells play in muscle regeneration, there is emerging evidence in rodents for a regulatory influence...

  17. Nutritional interventions to preserve skeletal muscle mass

    NARCIS (Netherlands)

    Backx, Evelien M.P.

    2016-01-01

    Muscle mass is the main predictor for muscle strength and physical function. The amount of muscle mass can decline rapidly during periods of reduced physical activity or during periods of energy intake restriction. For athletes, it is important to maintain muscle mass, since the loss of muscle is

  18. Sonographic swelling of pronator quadratus muscle in patients with occult bone injury

    International Nuclear Information System (INIS)

    Sato, Junko; Ishii, Yoshinori; Noguchi, Hideo; Toyabe, Shin-ichi

    2015-01-01

    The disarranged fat stripe of the pronator quadratus muscle (PQ) on radiographs (the PQ sign) is reported to be predictive of subtle bone fractures. This study aimed to report the results of magnetic resonance imaging (MRI) study in the patients in whom bone injury was not radiographically detected around the wrist joint, and the PQ was sonographically swollen following acute trauma. We evaluated sonographically the PQ of 55 patients who showed normal radiographs following acute trauma. The sonographic appearance of the PQ was checked on both longitudinal and transverse images. On the longitudinal image, the probe was positioned along the flexor carpi radialis tendon. For the transverse image, we adopted the image of the same level in which the PQ of the unaffected hand showed maximal thickness. The PQ was considered to be swollen with disproportionate hyperechogenicity and/or thickening compared with the unaffected side at least in one of the two images. Of the 55 patients, 25 patients whose PQ was considered to be swollen underwent MRI study. PQ thickness in millimeters was retrospectively measured on longitudinal and transverse sonographic images. Twenty-three patients (92.0%) had occult bone injury, and two adult patients (8.0%) showed only wrist joint effusion on MRI. Among these 23, the distal radius was the most frequent location of the occult bone injury (20 patients; 9 [36.0%] with an occult fracture line and 11 [44.0%] with bone bruising). In longitudinal image, the mean value of the PQ thickness of affected hands was 6.2 (3.7–9.6 mm; standard deviation [SD], 1.5) and that of unaffected hands was 4.5 (2.3–6.7 mm; SD, 1.2), respectively. In transverse image, that of dominant and nondominant hands was 7.6 (4.6–13.2 mm; SD, 2.0) and 5.5 (3.6–7.5 mm; SD, 1.1), respectively. The mean difference in PQ thickness between affected and unaffected hands was 1.7 (0.1–5.0 mm; SD, 1.1) in longitudinal image and 2.0 (0.3–6.8 mm; SD, 1.7) in transverse image

  19. Assessment of Myoelectric Controller Performance and Kinematic Behavior of a Novel Soft Synergy-inspired Robotic Hand for Prosthetic Applications

    Directory of Open Access Journals (Sweden)

    Simone Fani

    2016-10-01

    Full Text Available Myoelectric-artificial limbs can significantly advance the state of the art in prosthetics, since they can be used to control mechatronic devices through muscular activity in a way that mimics how the subjects used to activate their muscles before limb loss. However, surveys indicate that dissatisfaction with the functionality of terminal devices underlies the widespread abandonment of prostheses. We believe that one key factor to improve acceptability of prosthetic devices is to attain human-likeness of prosthesis movements, a goal which is being pursued by research on social and human-robot interactions. Therefore, to reduce early abandonment of terminal devices, we propose that controllers should be designed such as to ensure effective task accomplishment in a natural fashion. In this work, we have analyzed and compared the performance of three types of myoelectric controller algorithms based on surface electromyography to control an under-actuated and multi-degrees of freedom prosthetic hand, the SoftHand Pro. The goal of the present study was to identify the myoelectric algorithm that best mimics the native hand movements. As a preliminary step, we first quantified the repeatability of the SoftHand Pro finger movements and identified the electromyographic recording sites for able-bodied individuals with the highest signal-to-noise ratio from two pairs of muscles, i.e. flexor digitorum superficialis/extensor digitorum communis, and flexor carpi radialis/extensor carpi ulnaris. Able-bodied volunteers were then asked to execute reach-to-grasp movements, while electromyography signals were recorded from flexor digitorum superficialis/extensor digitorum communis as this was identified as the muscle pair characterized by high signal-to-noise ratio and intuitive control. Subsequently, we tested three myoelectric controllers that mapped electromyography signals to position of the SoftHand Pro. We found that a differential electromyography

  20. Trunk extensor muscle fatigue influences trunk muscle activities.

    Science.gov (United States)

    Hoseinpoor, Tahere Seyed; Kahrizi, Sedighe; Mobini, Bahram

    2015-01-01

    Trunk muscles fatigue is one of the risk factors in workplaces and daily activities. Loads would be redistributed among active and passive tissues in a non-optimal manner in fatigue conditions. Therefore, a single tissue might be overloaded with minimal loads and as a result the risk of injury would increase. The goal of this paper was to assess the electromyographic response of trunk extensor and abdominal muscles after trunk extensor muscles fatigue induced by cyclic lifting task. This was an experimental study that twenty healthy women participated. For assessing automatic response of trunk extensor and abdominal muscles before and after the fatigue task, electromyographic activities of 6 muscles: thorasic erector spine (TES), lumbar erector spine (LES), lumbar multifidus (LMF), transverse abdominis/ internal oblique (TrA/IO), rectus abdominis (RA) and external oblique (EO) were recorded in standing position with no load and symmetric axial loads equal to 25% of their body weights. Statistical analysis showed that all the abdominal muscles activity decreased with axial loads after performing fatigue task but trunk extensor activity remained constant. Results of the current study indicated that muscle recruitment strategies changed with muscle fatigue and load bearing, therefore risks of tissue injury may increase in fatigue conditions.

  1. Aspects of smooth muscle function in molluscan catch muscle.

    Science.gov (United States)

    Twarog, B M

    1976-10-01

    1) Catch in Mytilus ABRM may be a specialization of a mechanism common to all muscles that gives rise to stretch resistance in the resting state. Catch appears to be due to actin myosin interaction. Since this interaction is regulated by nerves, it provides a convenient model for studying resting stretch resistance. 2) Studies of the structure of Mytilus ABRM revela two types of intercellular connections: a) direct connections between muscle fibers [these nexal (gap) junctions interconnect the muscle cells electrically]; b) muscle fiber-collagen-muscle fiber connections [these provide mechanical connections between muscle cells via collagen fibers]. The structure of Mytilus ABRM supports speculation that smooth muscle filaments are organized into contractile units. 3) A rise in cAMP levels occurs in response to the relaxing transmitter, serotonin. It is not certain whether the cAMP system directly controls the ability of the contractile proteins to interact or whether it regulates intracellular levels of Ca2+. 4) Calcium ions in activation are derived from two sources: an internal source, probably the sarcoplasmic reticulum, and an external source, across the muscle membrane. 5) The nature of catch remains in question, although most evidence favors the linkage hypothesis.

  2. Skeletal muscle sodium channelopathies.

    Science.gov (United States)

    Nicole, Sophie; Fontaine, Bertrand

    2015-10-01

    This is an update on skeletal muscle sodium channelopathies since knowledge in the field have dramatically increased in the past years. The relationship between two phenotypes and SCN4A has been confirmed with additional cases that remain extremely rare: severe neonatal episodic laryngospasm mimicking encephalopathy, which should be actively searched for since patients respond well to sodium channel blockers; congenital myasthenic syndromes, which have the particularity to be the first recessive Nav1.4 channelopathy. Deep DNA sequencing suggests the contribution of other ion channels in the clinical expressivity of sodium channelopathies, which may be one of the factors modulating the latter. The increased knowledge of channel molecular structure, the quantity of sodium channel blockers, and the availability of preclinical models would permit a most personalized choice of medication for patients suffering from these debilitating neuromuscular diseases. Advances in the understanding of the molecular structure of voltage-gated sodium channels, as well as availability of preclinical models, would lead to improved medical care of patients suffering from skeletal muscle, as well as other sodium channelopathies.

  3. Muscle force compensation among synergistic muscles after fatigue of a single muscle.

    Science.gov (United States)

    Stutzig, Norman; Siebert, Tobias

    2015-08-01

    The aim of this study was to examine control strategies among synergistic muscles after fatigue of a single muscle. It was hypothesized that the compensating mechanism is specific for each fatigued muscle. The soleus (SOL), gastrocnemius lateralis (GL) and medialis (GM) were fatigued in separate sessions on different days. In each experiment, subjects (n = 11) performed maximal voluntary contractions prior to and after fatiguing a single muscle (SOL, GL or GM) while the voluntary muscle activity and torque were measured. Additionally, the maximal single twitch torque of the plantarflexors and the maximal spinal reflex activity (H-reflex) of the SOL, GL and GM were determined. Fatigue was evoked using neuromuscular stimulation. Following fatigue the single twitch torque decreased by -20.1%, -19.5%, and -23.0% when the SOL, GL, or GM, have been fatigued. The maximal voluntary torque did not decrease in any session but the synergistic voluntary muscle activity increased significantly. Moreover, we found no alterations in spinal reflex activity. It is concluded that synergistic muscles compensate each other. Furthermore, it seems that self-compensating mechanism of the fatigued muscles occurred additionally. The force compensation does not depend on the function of the fatigued muscle. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Building Muscles, Keeping Muscles: Protein Turnover During Space Flight

    Science.gov (United States)

    Ferrando, Arny; Bloomberg, Jacob; Lee, Angie (Technical Monitor)

    2002-01-01

    As we age we lose muscle mass and strength. The problem is a matter of use it or lose it and more - a fact to which any active senior can attest. An imbalance in the natural cycle of protein turnover may be a contributing factor to decreased muscle mass. But the answer is not so simple, since aging is associated with changes in hormones, activity levels, nutrition, and often, disease. The human body constantly uses amino acids to build muscle protein, which then breaks down and must be replaced. When protein turnover gets out of balance, so that more protein breaks down than the body can replace, the result is muscle loss. This is not just the bane of aging, however. Severely burned people may have difficulty building new muscle long after the burned skin has been repaired. Answers to why we lose muscle mass and strength - and how doctors can fix it - may come from space. Astronauts usually eat a well-balanced diet and maintain an exercise routine to stay in top health. During long-duration flight, they exercise regularly to reduce the muscle loss that results from being in a near-weightless environment. Despite these precautions, astronauts lose muscle mass and strength during most missions. They quickly recover after returning to Earth - this is a temporary condition in an otherwise healthy population. Members of the STS-107 crew are participating in a study of the effects of space flight, hormone levels, and stress on protein turnover. When we are under stress, the body responds with a change in hormone levels. Researchers hypothesize that this stress-induced change in hormones along with the near-weightlessness might result in the body synthesizing less muscle protein, causing muscles to lose their strength and size. Astronauts, who must perform numerous duties in a confined and unusual environment, experience some stress during their flight, making them excellent candidates for testing the researchers' hypothesis.

  5. Skeletal muscle regeneration is modulated by inflammation

    Directory of Open Access Journals (Sweden)

    Wenjun Yang

    2018-04-01

    Full Text Available Skeletal muscle regeneration is a complex process orchestrated by multiple steps. Recent findings indicate that inflammatory responses could play central roles in bridging initial muscle injury responses and timely muscle injury reparation. The various types of immune cells and cytokines have crucial roles in muscle regeneration process. In this review, we briefly summarise the functions of acute inflammation in muscle regeneration. The translational potential of this article: Immune system is closely relevant to the muscle regeneration. Understanding the mechanisms of inflammation in muscle regeneration is therefore critical for the development of effective regenerative, and therapeutic strategies in muscular disorders. This review provides information for muscle regeneration research regarding the effects of inflammation on muscle regeneration. Keywords: Chronic muscle disorders, Cytokines, Immune cells, Inflammation, Muscle regeneration, Muscle stem cells

  6. Muscle regeneration in mitochondrial myopathies

    DEFF Research Database (Denmark)

    Krag, T O; Hauerslev, S; Jeppesen, T D

    2013-01-01

    myopathies. We investigated regeneration in muscle biopsies from 61 genetically well-defined patients affected by mitochondrial myopathy. Our results show that the perturbed energy metabolism in mitochondrial myopathies causes ongoing muscle regeneration in a majority of patients, and some were even affected...

  7. Muscle ultrasound in neuromuscular disorders.

    NARCIS (Netherlands)

    Pillen, S.; Arts, I.M.P.; Zwarts, M.J.

    2008-01-01

    Muscle ultrasound is a useful tool in the diagnosis of neuromuscular disorders, as these disorders result in muscle atrophy and intramuscular fibrosis and fatty infiltration, which can be visualized with ultrasound. Several prospective studies have reported high sensitivities and specificities in

  8. Human skeletal muscle biochemical diversity.

    Science.gov (United States)

    Tirrell, Timothy F; Cook, Mark S; Carr, J Austin; Lin, Evie; Ward, Samuel R; Lieber, Richard L

    2012-08-01

    The molecular components largely responsible for muscle attributes such as passive tension development (titin and collagen), active tension development (myosin heavy chain, MHC) and mechanosensitive signaling (titin) have been well studied in animals but less is known about their roles in humans. The purpose of this study was to perform a comprehensive analysis of titin, collagen and MHC isoform distributions in a large number of human muscles, to search for common themes and trends in the muscular organization of the human body. In this study, 599 biopsies were obtained from six human cadaveric donors (mean age 83 years). Three assays were performed on each biopsy - titin molecular mass determination, hydroxyproline content (a surrogate for collagen content) and MHC isoform distribution. Titin molecular mass was increased in more distal muscles of the upper and lower limbs. This trend was also observed for collagen. Percentage MHC-1 data followed a pattern similar to collagen in muscles of the upper extremity but this trend was reversed in the lower extremity. Titin molecular mass was the best predictor of anatomical region and muscle functional group. On average, human muscles had more slow myosin than other mammals. Also, larger titins were generally associated with faster muscles. These trends suggest that distal muscles should have higher passive tension than proximal ones, and that titin size variability may potentially act to 'tune' the protein's mechanotransduction capability.

  9. The Basis of Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Antonio Musarò

    2014-01-01

    Full Text Available Muscle regeneration recapitulates many aspects of embryonic myogenesis and is an important homeostatic process of the adult skeletal muscle, which, after development, retains the capacity to regenerate in response to appropriate stimuli, activating the muscle compartment of stem cells, namely, satellite cells, as well as other precursor cells. Moreover, significant evidence suggests that while stem cells represent an important determinant for tissue regeneration, a “qualified” environment is necessary to guarantee and achieve functional results. It is therefore plausible that the loss of control over these cell fate decisions could lead to a pathological transdifferentiation, leading to pathologic defects in the regenerative process. This review provides an overview about the general aspects of muscle development and discusses the cellular and molecular aspects that characterize the five interrelated and time-dependent phases of muscle regeneration, namely, degeneration, inflammation, regeneration, remodeling, and maturation/functional repair.

  10. MR imaging of muscle diseases

    International Nuclear Information System (INIS)

    Kaiser, W.A.; Zeitler, E.; Schalke, B.C.G.

    1986-01-01

    Because of high soft-tissue contrast, MR imaging is especially suitable for the investigation of muscle diseases. Between March 1984 and March 1986, 76 patients with different types of muscle diseases were examined using a 1-T superconductive magnet (Siemens Magnetom). Studied were 14 patients with progressive muscular dystrophy (including carriers), 32 patients with myositis, four patients with myotonic dystrophy, six patients with spinal muscular atrophy, and 20 patients with other muscle diseases, including metabolic disorders. MR imaging showed typical signal patterns in affected muscle groups. These patterns can be used in the differential diagnosis, in biopsy planning, or in evaluation of response to therapy. The T1/T2 ratio especially seems to indicate very early stages of muscle disease

  11. Eccentric exercise-induced muscle damage impairs muscle glycogen repletion.

    Science.gov (United States)

    O'Reilly, K P; Warhol, M J; Fielding, R A; Frontera, W R; Meredith, C N; Evans, W J

    1987-07-01

    Five healthy untrained young male subjects were studied before, immediately after, and 10 days after a 45-min bout of eccentric exercise on a cycle ergometer (201 W). The subjects were sedentary at all other times and consumed a eucaloric meat-free diet. Needle biopsies of the vastus lateralis muscle were examined for intracellular damage and glycogen content. Immediately after exercise, muscle samples showed myofibrillar tearing and edema. At 10 days, there was myofibrillar necrosis, inflammatory cell infiltration, and no evidence of myofibrillar regeneration. Glycogen utilization during the exercise bout was 33 mmol glycosyl units/kg muscle, consistent with the metabolic intensity of 44% of maximal O2 uptake; however, the significant glycogen use by type II fibers contrasted with concentric exercise performed at this intensity. At 10 days after exercise, muscle glycogen was still depleted, in both type I and II fibers. It is possible that the alterations in muscle ultrastructures were related to the lack of repletion of muscle glycogen. Damage produced by eccentric exercise was more persistent than previously reported, indicating that more than 10 days may be necessary for recovery of muscle ultrastructure and carbohydrate reserves.

  12. Skeletal muscle connective tissue

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline

      The connective tissue content of skeletal muscle is believed to be the major factor responsible for defining the eating quality of different meat cuts, although attempts to correlate quantifications based on traditional histological methods have not as yet been able to prove this relation...... that collagen plays a significant role in determining the tenderness of meat. What are we missing? Therefore, fundamental aspects of connective tissue research have been the centre of attention throughout this thesis. A holistic view has been applied, glancing at this complex tissue which has many facets...... in this thesis that alpha-ketoglutarate, a tricarboxylic acid cycle metabolite, has the potential to control the metabolism of this particular tissue. Finally, a new microscopic method is introduced which allows the study of thermal denaturation of fibrillar collagen and myofibers in real time without any label...

  13. Bulk muscles, loose cables.

    Science.gov (United States)

    Liyanage, Chamari R D G; Kodali, Venkata

    2014-10-17

    The accessibility and usage of body building supplements is on the rise with stronger internet marketing strategies by the industry. The dangers posed by the ingredients in them are underestimated. A healthy young man came to the emergency room with palpitations and feeling unwell. Initial history and clinical examination were non-contributory to find the cause. ECG showed atrial fibrillation. A detailed history for any over the counter or herbal medicine use confirmed that he was taking supplements to bulk muscle. One of the components in these supplements is yohimbine; the onset of symptoms coincided with the ingestion of this product and the patient is symptom free after stopping it. This report highlights the dangers to the public of consuming over the counter products with unknown ingredients and the consequential detrimental impact on health. 2014 BMJ Publishing Group Ltd.

  14. Muscling out malaria

    DEFF Research Database (Denmark)

    Hughes, David Peter; Boomsma, Jacobus Jan

    2006-01-01

    ) [2] highlighted the back-to-back articles in Science 3 and 4 that demonstrated the potential biocontrol of malaria by targeting mosquitoes with entomopathogenic fungi (Metarhizium and Beauveria spp.). The wide impact of the original articles and the need to find alternatives to pesticidal control...... where malaria is endemic, humanity cannot afford shortcuts, because any failures owing to poor management or premature implementation will reduce local governmental support rather than enhance it (Andrew Read, pers. commun.). Therefore, if we are to ‘muscle out malaria', well...... of key importance, and the new focus on fungal biocontrol of malaria should therefore act as a catalyst for further research on the basic biology of fungal pathogens. Understanding morphological, biochemical or immune system-based resistance to insect pathogenic fungi will be easier if we know...

  15. Skeletal muscle connective tissue

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline

    that collagen plays a significant role in determining the tenderness of meat. What are we missing? Therefore, fundamental aspects of connective tissue research have been the centre of attention throughout this thesis. A holistic view has been applied, glancing at this complex tissue which has many facets......  The connective tissue content of skeletal muscle is believed to be the major factor responsible for defining the eating quality of different meat cuts, although attempts to correlate quantifications based on traditional histological methods have not as yet been able to prove this relation....... Collagen, being the major protein in connective tissue, has been extensively investigated with regard to its relation to meat tenderness, but the results have been rather conflicting. Meat from older animals is tougher than that from younger animals, and changes in the properties of the collagen due...

  16. Physics of muscle contraction

    Science.gov (United States)

    Caruel, M.; Truskinovsky, L.

    2018-03-01

    In this paper we report, clarify and broaden various recent efforts to complement the chemistry-centered models of force generation in (skeletal) muscles by mechanics-centered models. The physical mechanisms of interest can be grouped into two classes: passive and active. The main passive effect is the fast force recovery which does not require the detachment of myosin cross-bridges from actin filaments and can operate without a specialized supply of metabolic fuel (ATP). In mechanical terms, it can be viewed as a collective folding-unfolding phenomenon in the system of interacting bi-stable units and modeled by near equilibrium Langevin dynamics. The active force generation mechanism operates at slow time scales, requires detachment and is crucially dependent on ATP hydrolysis. The underlying mechanical processes take place far from equilibrium and are represented by stochastic models with broken time reversal symmetry implying non-potentiality, correlated noise or multiple reservoirs. The modeling approaches reviewed in this paper deal with both active and passive processes and support from the mechanical perspective the biological point of view that phenomena involved in slow (active) and fast (passive) force generation are tightly intertwined. They reveal, however, that biochemical studies in solution, macroscopic physiological measurements and structural analysis do not provide by themselves all the necessary insights into the functioning of the organized contractile system. In particular, the reviewed body of work emphasizes the important role of long-range interactions and criticality in securing the targeted mechanical response in the physiological regime of isometric contractions. The importance of the purely mechanical micro-scale modeling is accentuated at the end of the paper where we address the puzzling issue of the stability of muscle response on the so called ‘descending limb’ of the isometric tetanus.

  17. 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

  18. Muscle channelopathies and electrophysiological approach

    Directory of Open Access Journals (Sweden)

    Cherian Ajith

    2008-01-01

    Full Text Available Myotonic syndromes and periodic paralyses are rare disorders of skeletal muscle characterized mainly by muscle stiffness or episodic attacks of weakness. Familial forms are caused by mutation in genes coding for skeletal muscle voltage ionic channels. Familial periodic paralysis and nondystrophic myotonias are disorders of skeletal muscle excitability caused by mutations in genes coding for voltage-gated ion channels. These diseases are characterized by episodic failure of motor activity due to muscle weakness (paralysis or stiffness (myotonia. Clinical studies have identified two forms of periodic paralyses: hypokalemic periodic paralysis (hypoKPP and hyperkalemic periodic paralysis (hyperKPP, based on changes in serum potassium levels during the attacks, and three distinct forms of myotonias: paramyotonia congenita (PC, potassium-aggravated myotonia (PAM, and myotonia congenita (MC. PC and PAM have been linked to missense mutations in the SCN4A gene, which encodes α subunit of the voltage-gated sodium channel, whereas MC is caused by mutations in the chloride channel gene (CLCN1. Exercise is known to trigger, aggravate, or relieve symptoms. Therefore, exercise can be used as a functional test in electromyography to improve the diagnosis of these muscle disorders. Abnormal changes in the compound muscle action potential can be disclosed using different exercise tests. Five electromyographic (EMG patterns (I-V that may be used in clinical practice as guides for molecular diagnosis are discussed.

  19. Immunology Guides Skeletal Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    F. Andrea Sass

    2018-03-01

    Full Text Available Soft tissue trauma of skeletal muscle is one of the most common side effects in surgery. Muscle injuries are not only caused by accident-related injuries but can also be of an iatrogenic nature as they occur during surgical interventions when the anatomical region of interest is exposed. If the extent of trauma surpasses the intrinsic regenerative capacities, signs of fatty degeneration and formation of fibrotic scar tissue can occur, and, consequentially, muscle function deteriorates or is diminished. Despite research efforts to investigate the physiological healing cascade following trauma, our understanding of the early onset of healing and how it potentially determines success or failure is still only fragmentary. This review focuses on the initial physiological pathways following skeletal muscle trauma in comparison to bone and tendon trauma and what conclusions can be drawn from new scientific insights for the development of novel therapeutic strategies. Strategies to support regeneration of muscle tissue after injury are scarce, even though muscle trauma has a high incidence. Based on tissue specific differences, possible clinical treatment options such as local immune-modulatory and cell therapeutic approaches are suggested that aim to support the endogenous regenerative potential of injured muscle tissues.

  20. Immunology Guides Skeletal Muscle Regeneration.

    Science.gov (United States)

    Sass, F Andrea; Fuchs, Michael; Pumberger, Matthias; Geissler, Sven; Duda, Georg N; Perka, Carsten; Schmidt-Bleek, Katharina

    2018-03-13

    Soft tissue trauma of skeletal muscle is one of the most common side effects in surgery. Muscle injuries are not only caused by accident-related injuries but can also be of an iatrogenic nature as they occur during surgical interventions when the anatomical region of interest is exposed. If the extent of trauma surpasses the intrinsic regenerative capacities, signs of fatty degeneration and formation of fibrotic scar tissue can occur, and, consequentially, muscle function deteriorates or is diminished. Despite research efforts to investigate the physiological healing cascade following trauma, our understanding of the early onset of healing and how it potentially determines success or failure is still only fragmentary. This review focuses on the initial physiological pathways following skeletal muscle trauma in comparison to bone and tendon trauma and what conclusions can be drawn from new scientific insights for the development of novel therapeutic strategies. Strategies to support regeneration of muscle tissue after injury are scarce, even though muscle trauma has a high incidence. Based on tissue specific differences, possible clinical treatment options such as local immune-modulatory and cell therapeutic approaches are suggested that aim to support the endogenous regenerative potential of injured muscle tissues.

  1. Skeletal muscle performance and ageing.

    Science.gov (United States)

    Tieland, Michael; Trouwborst, Inez; Clark, Brian C

    2018-02-01

    The world population is ageing rapidly. As society ages, the incidence of physical limitations is dramatically increasing, which reduces the quality of life and increases healthcare expenditures. In western society, ~30% of the population over 55 years is confronted with moderate or severe physical limitations. These physical limitations increase the risk of falls, institutionalization, co-morbidity, and premature death. An important cause of physical limitations is the age-related loss of skeletal muscle mass, also referred to as sarcopenia. Emerging evidence, however, clearly shows that the decline in skeletal muscle mass is not the sole contributor to the decline in physical performance. For instance, the loss of muscle strength is also a strong contributor to reduced physical performance in the elderly. In addition, there is ample data to suggest that motor coordination, excitation-contraction coupling, skeletal integrity, and other factors related to the nervous, muscular, and skeletal systems are critically important for physical performance in the elderly. To better understand the loss of skeletal muscle performance with ageing, we aim to provide a broad overview on the underlying mechanisms associated with elderly skeletal muscle performance. We start with a system level discussion and continue with a discussion on the influence of lifestyle, biological, and psychosocial factors on elderly skeletal muscle performance. Developing a broad understanding of the many factors affecting elderly skeletal muscle performance has major implications for scientists, clinicians, and health professionals who are developing therapeutic interventions aiming to enhance muscle function and/or prevent mobility and physical limitations and, as such, support healthy ageing. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  2. Quinine for muscle cramps.

    Science.gov (United States)

    El-Tawil, Sherif; Al Musa, Tarique; Valli, Haseeb; Lunn, Michael P T; Brassington, Ruth; El-Tawil, Tariq; Weber, Markus

    2015-04-05

    Muscle cramps can occur anywhere and for many reasons. Quinine has been used to treat cramps of all causes. However, controversy continues about its efficacy and safety. This review was first published in 2010 and searches were updated in 2014. To assess the efficacy and safety of quinine-based agents in treating muscle cramps. On 27 October 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE. We searched reference lists of articles up to 2014. We also searched for ongoing trials in November 2014. Randomised controlled trials of people of all ages with muscle cramps in any location and of any cause, treated with quinine or its derivatives. Three review authors independently selected trials for inclusion, assessed risk of bias and extracted data. We contacted study authors for additional information. For comparisons including more than one trial, we assessed the quality of the evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE). We identified 23 trials with a total of 1586 participants. Fifty-eight per cent of these participants were from five unpublished studies. Quinine was compared to placebo (20 trials, n = 1140), vitamin E (four trials, n = 543), a quinine-vitamin E combination (three trials, n = 510), a quinine-theophylline combination (one trial, n = 77), and xylocaine injections into the gastrocnemius muscle (one trial, n = 24). The most commonly used quinine dosage was 300 mg/day (range 200 to 500 mg). We found no new trials for inclusion when searches were updated in 2014.The risk of bias in the trials varied considerably. All 23 trials claimed to be randomised, but only a minority described randomisation and allocation concealment adequately.Compared to placebo, quinine significantly reduced cramp number over two weeks by 28%, cramp intensity by 10%, and cramp days by 20%. Cramp duration was not significantly affected.A significantly greater number of people

  3. Elicitability of muscle cramps in different leg and foot muscles.

    Science.gov (United States)

    Minetto, Marco Alessandro; Botter, Alberto

    2009-10-01

    To explore the efficacy of muscle motor point stimulation in eliciting muscle cramps, 11 subjects underwent eight sessions of electrical stimulation of the following muscles bilaterally: abductor hallucis flexor hallucis brevis, and both heads of the gastrocnemius muscles. Bursts of 150 square wave stimuli (duration: 152 micros; current intensity: 30% supramaximal) were applied. The stimulation frequency was increased from 4 pulses per second (pps) at increments of 2 pps until a cramp was induced. The number of cramps that could be elicited was smaller in flexor hallucis brevis than in abductor hallucis (16 vs. 22 out of 22 trials each; P cramp susceptibility, and the intermuscle variability in the elicitability profile for electrically induced cramps supports the use of the proposed method for cramp research.

  4. The calf muscle pump revisited.

    Science.gov (United States)

    Williams, Katherine J; Ayekoloye, Olufemi; Moore, Hayley M; Davies, Alun H

    2014-07-01

    Chronic venous disease (CVD) defines the spectrum of manifestations of venous disease that originate as a result of ambulatory venous hypertension. Thus far, the role of the calf muscle pump in the development and potentiation of CVD has been overlooked and understated in the clinical setting, with much greater emphasis placed on reflux and obstruction. The aim of this review is to explore the level of significance that calf muscle pump function or dysfunction bears on the development and potentiation of CVD. EMBASE and MEDLINE databases were searched with keywords "calf" AND "muscle" AND "pump" AND "venous" AND "insufficiency" AND ("lower limb*" OR "leg*"), screened for cross-sectional and longitudinal studies relating to chronic venous insufficiency, highlighting the role of the calf muscle pump in CVD and the extent to which the calf muscle pump is impaired in these cases. This resulted in the inclusion of 10 studies. Compared with healthy subjects, patients with CVD have a reduced ejection fraction (15.9%; P calf muscle pump ejection ability as well as poor venous competence. Calf muscle pump dysfunction is present in 55% of patients with CVD in the literature, but this did not reach significance on meta-analysis. Isotonic exercise programs in patients with active and healed ulcers have been shown to increase calf muscle pump function but not venous competence. Calf muscle pump failure is a therapeutic target in the treatment of CVD. Evidence suggests that isotonic exercise treatment may be an effective method of increasing the hemodynamic performance of the calf muscle pump. This review emphasizes the requirement for more attention to be placed on the treatment of calf muscle pump failure in cases of CVD by use of exercise treatment programs or other methods, which may be of clinical importance in managing symptomatic disease. To establish this in routine clinical practice, these results would need to be replicated in appropriate clinical trials. It would

  5. Bigorexia: bodybuilding and muscle dysmorphia.

    Science.gov (United States)

    Mosley, Philip E

    2009-05-01

    Muscle dysmorphia is an emerging condition that primarily affects male bodybuilders. Such individuals obsess about being inadequately muscular. Compulsions include spending hours in the gym, squandering excessive amounts of money on ineffectual sports supplements, abnormal eating patterns or even substance abuse. In this essay, I illustrate the features of muscle dysmorphia by employing the first-person account of a male bodybuilder afflicted by this condition. I briefly outline the history of bodybuilding and examine whether the growth of this sport is linked to a growing concern with body image amongst males. I suggest that muscle dysmorphia may be a new expression of a common pathology shared with the eating disorders.

  6. Diabetic muscle infarction: radiologic evaluation

    International Nuclear Information System (INIS)

    Chason, D.P.; Fleckenstein, J.L.; Burns, D.K.; Rojas, G.

    1996-01-01

    Four patients with severe diabetes mellitus presenting with acute thigh pain, tenderness, and swelling were evaluated by imaging techniques and biopsy. Edema in the affected muscles was seen in two patients with MRI studies. Femoral artery calcification and mild muscle swelling was present in one patient who underwent CT. Decreased echogenicity was seen in the involved muscle in a patient studied with ultrasound. Serum enzymes were normal or mildly elevated in three patients (not reported in one). Biopsy demonstrated necrosis and regenerative change in all cases. MRI, although nonspecific, is the best imaging technique to suggest the diagnosis of DMI in the appropriate clinical setting, thereby obviating biopsy. (orig./MG)

  7. Muscle mass, muscle strength, and muscle fat infiltration as predictors of incident mobility limitations in well-functioning older persons

    NARCIS (Netherlands)

    Visser, Marjolein; Goodpaster, Bret H; Kritchevsky, Stephen B; Newman, Anne B; Nevitt, Michael; Rubin, Susan M; Simonsick, Eleanor M; Harris, Tamara B

    BACKGROUND: Lower muscle mass has been correlated with poor physical function; however, no studies have examined this relationship prospectively. This study aims to investigate whether low muscle mass, low muscle strength, and greater fat infiltration into the muscle predict incident mobility

  8. Muscle strength and muscle endurance: with and without creatine supplementation

    OpenAIRE

    KEBRIT, Daniel; RANI, Sangeeta

    2014-01-01

    Creatine is one of the legal ergogenic aids which are used by athletes here and there. A number of studies assured that it has a positive effect in high intensity short duration intensity exercise performances. This study tried to evaluate the effect of creatine monohydrate supplements on muscle strength and muscle endurance. Twenty subjects (CG= 10 and EG= 10) were participated in three months of exercise training. In this study complete randomized design was used. The EG consumed creatine a...

  9. Muscle soreness and delayed-onset muscle soreness.

    Science.gov (United States)

    Lewis, Paul B; Ruby, Deana; Bush-Joseph, Charles A

    2012-04-01

    Immediate and delayed-onset muscle soreness differ mainly in chronology of presentation. Both conditions share the same quality of pain, eliciting and relieving activities and a varying degree of functional deficits. There is no single mechanism for muscle soreness; instead, it is a culmination of 6 different mechanisms. The developing pathway of DOMS begins with microtrauma to muscles and then surrounding connective tissues. Microtrauma is then followed by an inflammatory process and subsequent shifts of fluid and electrolytes. Throughout the progression of these events, muscle spasms may be present, exacerbating the overall condition. There are a multitude of modalities to manage the associated symptoms of immediate soreness and DOMS. Outcomes of each modality seem to be as diverse as the modalities themselves. The judicious use of NSAIDs and continued exercise are suggested to be the most reliable methods and recommended. This review article and each study cited, however, represent just one part of the clinician's decisionmaking process. Careful affirmation of temporary deficits from muscle soreness is not to be taken lightly, nor is the advisement and medical management of muscle soreness prescribed by the clinician.

  10. Ethanol Exposure Causes Muscle Degeneration in Zebrafish

    Directory of Open Access Journals (Sweden)

    Elizabeth C. Coffey

    2018-03-01

    Full Text Available Alcoholic myopathies are characterized by neuromusculoskeletal symptoms such as compromised movement and weakness. Although these symptoms have been attributed to neurological damage, EtOH may also target skeletal muscle. EtOH exposure during zebrafish primary muscle development or adulthood results in smaller muscle fibers. However, the effects of EtOH exposure on skeletal muscle during the growth period that follows primary muscle development are not well understood. We determined the effects of EtOH exposure on muscle during this phase of development. Strikingly, muscle fibers at this stage are acutely sensitive to EtOH treatment: EtOH induces muscle degeneration. The severity of EtOH-induced muscle damage varies but muscle becomes more refractory to EtOH as muscle develops. NF-kB induction in muscle indicates that EtOH triggers a pro-inflammatory response. EtOH-induced muscle damage is p53-independent. Uptake of Evans blue dye shows that EtOH treatment causes sarcolemmal instability before muscle fiber detachment. Dystrophin-null sapje mutant zebrafish also exhibit sarcolemmal instability. We tested whether Trichostatin A (TSA, which reduces muscle degeneration in sapje mutants, would affect EtOH-treated zebrafish. We found that TSA and EtOH are a lethal combination. EtOH does, however, exacerbate muscle degeneration in sapje mutants. EtOH also disrupts adhesion of muscle fibers to their extracellular matrix at the myotendinous junction: some detached muscle fibers retain beta-Dystroglycan indicating failure of muscle end attachments. Overexpression of Paxillin, which reduces muscle degeneration in zebrafish deficient for beta-Dystroglycan, is not sufficient to rescue degeneration. Taken together, our results suggest that EtOH exposure has pleiotropic deleterious effects on skeletal muscle.

  11. Compensatory Hypertrophy of Skeletal Muscle: Contractile Characteristics

    Science.gov (United States)

    Ianuzzo, C. D.; Chen, V.

    1977-01-01

    Describes an experiment using rats that demonstrates contractile characteristics of normal and hypertrophied muscle. Compensatory hypertrophy of the plantaris muscle is induced by surgical removal of the synergistic gastrocnemium muscle. Includes methods for determination of contractile properties of normal and hypertrophied muscle and…

  12. Muscle pain | Mogole | South African Family Practice

    African Journals Online (AJOL)

    Muscle pain, also known as myalgia, is most commonly associated with sprains or strains. It frequently presents as redness at the site of injury, tenderness, swelling and fever. Muscle pain may occur as a result of excitation of the muscle nociceptor due to overuse of the muscle, viral infections or trauma. The most important ...

  13. Quantitative muscle ultrasonography in amyotrophic lateral sclerosis.

    NARCIS (Netherlands)

    Arts, I.M.P.; Rooij, F.G. van; Overeem, S.; Pillen, S.; Janssen, H.M.; Schelhaas, H.J.; Zwarts, M.J.

    2008-01-01

    In this study, we examined whether quantitative muscle ultrasonography can detect structural muscle changes in early-stage amyotrophic lateral sclerosis (ALS). Bilateral transverse scans were made of five muscles or muscle groups (sternocleidomastoid, biceps brachii/brachialis, forearm flexor group,

  14. Diabetic muscle infarction: atypical MR appearance

    International Nuclear Information System (INIS)

    Sharma, P.; Mangwana, S.; Kapoor, R.K.

    2000-01-01

    We describe a case of diabetic muscle infarction which had atypical features of hyperintensity of the affected muscle on T1-weighted images. Biopsy was performed which revealed diffuse extensive hemorrhage within the infarcted muscle. We believe increased signal intensity on T1-weighted images should suggest hemorrhage within the infarcted muscle. (orig.)

  15. Unconventional Functions of Muscles in Planarian Regeneration.

    Science.gov (United States)

    Cutie, Stephen; Hoang, Alison T; Payumo, Alexander Y; Huang, Guo N

    2017-12-18

    Muscles are traditionally considered in the context of force generation. Scimone et al. (2017), reporting in Nature, now examine muscles in a developmental setting and find unexpected roles for distinct planarian muscle fibers. The authors show that muscles provide patterning signals to promote regeneration and guide tissue growth after injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Exercise-induced muscle modifications

    International Nuclear Information System (INIS)

    Kerviler, E. de; Willig, A.L.; Jehenson, P.; Duboc, D.; Syrota, A.

    1990-01-01

    This paper compares changes in muscle proton T2 after exercise in normal subjects and in patients with muscular glycogenoses. Four patients suffering from muscular glycogenosis and eight normal volunteers were studied. Muscle T2s were measured in forearm muscles at rest and after exercise, with a 0.5-T imager. The exercise was performed with handgrips and was evaluated by P-31 spectroscopy (end-exercise decrease in pH and phosphocreatine) performed with a 2-T magnet. In normal subjects, a relative T2 increase, ranging from 14% to 44%, was observed in the exercised muscles. In the patients, who cannot produce lactate during exercise, weak pH variation occurred, and only a slight T2 increase (7% - 9%) was observed

  17. Simvastatin effects on skeletal muscle

    DEFF Research Database (Denmark)

    Larsen, Steen; Stride, Nis; Hey-Mogensen, Martin

    2013-01-01

    Glucose tolerance and skeletal muscle coenzyme Q(10) (Q(10)) content, mitochondrial density, and mitochondrial oxidative phosphorylation (OXPHOS) capacity were measured in simvastatin-treated patients (n = 10) and in well-matched control subjects (n = 9)....

  18. Muscle dysfunction in cancer patients

    DEFF Research Database (Denmark)

    Christensen, Jesper Frank; Jones, L W; Andersen, J L

    2014-01-01

    dysfunction in cancer patients lies in the correlation to vital clinical end points such as cancer-specific and all-cause mortality, therapy complications and quality of life (QoL). Such associations strongly emphasize the need for effective therapeutic countermeasures to be developed and implemented......BACKGROUND: Muscle dysfunction is a prevalent phenomenon in the oncology setting where patients across a wide range of diagnoses are subject to impaired muscle function regardless of tumor stage and nutritional state. Here, we review the current evidence describing the degree, causes and clinical...... dysfunction is evident across all stages of the cancer trajectory. The causes of cancer-related muscle dysfunction are complex, but may involve a wide range of tumor-, therapy- and/or lifestyle-related factors, depending on the clinical setting of the individual patient. The main importance of muscle...

  19. Muscle Activation and Movement Coordination.

    OpenAIRE

    Ljung, Carl

    2014-01-01

    The purpose of this project was to empirically develop a method of using electromyography to identify how humans coordinate their muscles during certain sequences of movement and the effect of an injured anterior cruciate ligament to muscle coordination. In this study, more simple movements of the lower extremities are examined and relatively accurate hypothesizes can be made solely based on anatomical theory. However, a general method for electromyographic studies would open up the possibili...

  20. Determinants of muscle carnosine content.

    Science.gov (United States)

    Harris, R C; Wise, J A; Price, K A; Kim, H J; Kim, C K; Sale, C

    2012-07-01

    The main determinant of muscle carnosine (M-Carn) content is undoubtedly species, with, for example, aerobically trained female vegetarian athletes [with circa 13 mmol/kg dry muscle (dm)] having just 1/10th of that found in trained thoroughbred horses. Muscle fibre type is another key determinant, as type II fibres have a higher M-Carn or muscle histidine containing dipeptide (M-HCD) content than type I fibres. In vegetarians, M-Carn is limited by hepatic synthesis of β-alanine, whereas in omnivores this is augmented by the hydrolysis of dietary supplied HCD's resulting in muscle levels two or more times higher. β-alanine supplementation will increase M-Carn. The same increase in M-Carn occurs with administration of an equal molar quantity of carnosine as an alternative source of β-alanine. Following the cessation of supplementation, M-Carn returns to pre-supplementation levels, with an estimated t1/2 of 5-9 weeks. Higher than normal M-Carn contents have been noted in some chronically weight-trained subjects, but it is unclear if this is due to the training per se, or secondary to changes in muscle fibre composition, an increase in β-alanine intake or even anabolic steroid use. There is no measureable loss of M-Carn with acute exercise, although exercise-induced muscle damage may result in raised plasma concentrations in equines. Animal studies indicate effects of gender and age, but human studies lack sufficient control of the effects of diet and changes in muscle fibre composition.

  1. Influence of muscle geometry on shortening speed of fibre, aponeurosis and muscle

    NARCIS (Netherlands)

    Zuurbier, C. J.; Huijing, P. A.

    1992-01-01

    The influence of muscle geometry on muscle shortening of the gastrocnemius medialis muscle (GM) of the rat was studied. Using cinematography, GM geometry was studied during isokinetic concentric activity at muscle lengths ranging from 85 to 105% of the optimum muscle length. The shortening speed of

  2. Assessment of muscle fatigue using electromygraphm sensing

    Science.gov (United States)

    Helmi, Muhammad Hazimin Bin; Ping, Chew Sue; Ishak, Nur Elliza Binti; Saad, Mohd Alimi Bin Mohd; Mokhtar, Anis Shahida Niza Binti

    2017-08-01

    Muscle fatigue is condition of muscle decline in ability after undergoing any physical activity. Observation of the muscle condition of an athlete during training is crucial to prevent or minimize injury and able to achieve optimum performance in actual competition. The aim of this project is to develop a muscle monitoring system to detect muscle fatigue in swimming athlete. This device is capable to measure muscle stress level of the swimmer and at the same time provide indication of muscle fatigue level to trainer. Electromyography signal was recorded from the muscle movement while practicing the front crawl stroke repetitively. The time domain data was processed to frequency spectra in order to study the effect of muscle fatigue. The results show that the recorded EMG signal is able to sense muscle fatigue.

  3. Variability of femoral muscle attachments.

    Science.gov (United States)

    Duda, G N; Brand, D; Freitag, S; Lierse, W; Schneider, E

    1996-09-01

    Analytical and experimental models of the musculoskeletal system often assume single values rather than ranges for anatomical input parameters. The hypothesis of the present study was that anatomical variability significantly influences the results of biomechanical analyses, specifically regarding the moment arms of the various thigh muscles. Insertions and origins of muscles crossing or attaching to the femur were digitized in six specimens. Muscle volumes were measured; muscle attachment area and centroid location were computed. To demonstrate the influence of inter-individual anatomic variability on a mechanical modeling parameter, the corresponding range of muscle moment arms were calculated. Standard deviations, as a percentage of the mean, were about 70% for attachment area and 80% for muscle volume and attachment centroid location. The resulting moment arms of the m. gluteus maximus and m. rectus femoris were especially sensitive to anatomical variations (SD 65%). The results indicate that sensitivity to anatomical variations should be analyzed in any investigation simulating musculoskeletal interactions. To avoid misinterpretations, investigators should consider using several anatomical configurations rather than relying on a mean data set.

  4. Morphology of peroneus tertius muscle.

    Science.gov (United States)

    Joshi, S D; Joshi, S S; Athavale, S A

    2006-10-01

    Peroneus tertius (PT) muscle is peculiar to man, and man is the only member among the primates in whom this muscle occurs. The muscle is variable in its development and attachment. Because of functional demands of bipedal gait and plantigrade foot, part of extensor digitorum brevis (EDB) has migrated upwards into the leg from the dorsum of foot. PT is a muscle that evolution is rendering more important. In a total of 110 cadavers, extensor compartment of leg and dorsum of foot were dissected in both the lower limbs and extensor digitorum longus (EDL), and PT muscles were dissected and displayed. PT was found to be absent in 10.5% limbs, the incidence being greater on the right side. The remaining limbs in which the PT muscle was present had a very extensive origin from lower 3/4th of extensor surface of fibula (20% on right and in 17% on left), and the EDL was very much reduced in size. In approximately 12%, the tendon of PT was thick or even thicker than the tendon of EDL. In 4%, the tendon extended beyond fifth metatarsal up to metatarsophalangeal joint of fifth toe, and in 1.5%, it extended up to the proximal phalanx of little toe. In two cases (both on the right side), where PT was absent, it was replaced by a slip from lateral margin of EDL. We conclude that PT, which is preeminently human, is extending its purchase both proximally and distally. Copyright 2006 Wiley-Liss, Inc.

  5. Mitochondrial respiration in hummingbird flight muscles.

    OpenAIRE

    Suarez, R K; Lighton, J R; Brown, G S; Mathieu-Costello, O

    1991-01-01

    Respiration rates of muscle mitochondria in flying hummingbirds range from 7 to 10 ml of O2 per cm3 of mitochondria per min, which is about 2 times higher than the range obtained in the locomotory muscles of mammals running at their maximum aerobic capacities (VO2max). Capillary volume density is higher in hummingbird flight muscles than in mammalian skeletal muscles. Mitochondria occupy approximately 35% of fiber volume in hummingbird flight muscles and cluster beneath the sarcolemmal membra...

  6. Muscle ultrasound measurements and functional muscle parameters in non-dystrophic myotonias suggest structural muscle changes.

    NARCIS (Netherlands)

    Trip, J.; Pillen, S.; Faber, C.G.; Engelen, B.G.M. van; Zwarts, M.J.; Drost, G.

    2009-01-01

    Patients with non-dystrophic myotonias, including chloride (myotonia congenita) and sodium channelopathies (paramyotonia congenita/potassium aggravated myotonias), may show muscular hypertrophy in combination with some histopathological abnormalities. However, the extent of muscle changes has never

  7. Effect of acupuncture depth on muscle pain

    Directory of Open Access Journals (Sweden)

    Kitakoji Hiroshi

    2011-06-01

    Full Text Available Abstract Background While evidence supports efficacy of acupuncture and/or dry needling in treating musculoskeletal pain, it is unclear which needling method is most effective. This study aims to determine the effects of depth of needle penetration on muscle pain. Methods A total of 22 healthy volunteers performed repeated eccentric contractions to induce muscle soreness in their extensor digital muscle. Subjects were assigned randomly to four groups, namely control group, skin group (depth of 3 mm: the extensor digital muscle, muscle group (depth of 10 mm: the extensor digital muscle and non-segmental group (depth of 10 mm: the anterior tibial muscle. Pressure pain threshold and electrical pain threshold of the skin, fascia and muscle were measured at a point 20 mm distal to the maximum tender point on the second day after the exercise. Results Pressure pain thresholds of skin group (depth of 3 mm: the extensor digital muscle and muscle group (depth of 10 mm: the extensor digital muscle were significantly higher than the control group, whereas the electrical pain threshold at fascia of muscle group (depth of 10 mm: the extensor digital muscle was a significantly higher than control group; however, there was no significant difference between the control and other groups. Conclusion The present study shows that acupuncture stimulation of muscle increases the PPT and EPT of fascia. The depth of needle penetration is important for the relief of muscle pain.

  8. MR Imaging and US of the Wrist Tendons.

    Science.gov (United States)

    Plotkin, Benjamin; Sampath, Srihari C; Sampath, Srinath C; Motamedi, Kambiz

    2016-10-01

    The tendons of the wrist are commonly symptomatic. They can be injured, infected, or inflamed. Magnetic resonance imaging and ultrasonography are useful tools for evaluating the wrist. Pathologic conditions of the wrist tendons include de Quervain tenosynovitis, extensor carpi ulnaris tendinopathy, rheumatoid tenosynovitis, infectious synovitis, tendon tears, hydroxyapatite deposition disease, intersection syndrome, tenosynovial giant cell tumor, and fibroma of the tendon sheath. In this article, we review the normal appearance of the wrist tendons, discuss relevant anatomy, and give an overview of common pathologic conditions affecting the wrist tendons. Online supplemental material is available for this article. © RSNA, 2016.

  9. Novel muscle spindles containing muscle fibers devoid of sensory innervation in the extensor digitorum longus muscle of aged rats.

    Science.gov (United States)

    Desaki, Junzo; Nishida, Naoya

    2008-04-01

    We examined the structural features of muscle spindles at the equatorial and juxtaequatorial regions in the extensor digitorum longus muscle of adult (12 months) and aged (25 months) rats. In aged muscle spindles, the lamellated layers of the spindle capsule were a little increased in number compared to those in the adult ones. Two novel muscle spindles were observed in the aged muscle. In one muscle spindle, the spindle capsule contained four thin intrafusal muscle fibers invested by the inner capsule and two muscle fibers between the layers of the spindle capsule. Serial semithin sections revealed that the latter lacked the investment of the spindle capsule at the polar region. The other muscle spindle contained four intrafusal muscle fibers: two thin sensory-innervated muscle fibers invested by the inner capsule and two thick muscle fibers similar in structural features to neighboring extrafusal muscle fibers and lacking sensory innervation within the wide periaxial space. These findings suggest that two muscle fibers between the layers of the spindle capsule may be invested by the newly formed capsular cells during aging, while two thick fibers within the periaxial space may fail to receive the sensory innervation during the early development and follow the course of extrafusal fiber differentiation.

  10. Empirical Evaluation of Voluntarily Activatable Muscle Synergies

    Directory of Open Access Journals (Sweden)

    Shunta Togo

    2017-09-01

    Full Text Available The muscle synergy hypothesis assumes that individual muscle synergies are independent of each other and voluntarily controllable. However, this assumption has not been empirically tested. This study tested if human subjects can voluntarily activate individual muscle synergies extracted by non-negative matrix factorization (NMF, the standard mathematical method for synergy extraction. We defined the activation of a single muscle synergy as the generation of a muscle activity pattern vector parallel to the single muscle synergy vector. Subjects performed an isometric force production task with their right hand, and the 13 muscle activity patterns associated with their elbow and shoulder movements were measured. We extracted muscle synergies during the task using electromyogram (EMG data and the NMF method with varied numbers of muscle synergies. The number (N of muscle synergies was determined by using the variability accounted for (VAF, NVAF and the coefficient of determination (CD, NCD. An additional muscle synergy model with NAD was also considered. We defined a conventional muscle synergy as the muscle synergy extracted by the NVAF, NCD, and NAD. We also defined an extended muscle synergy as the muscle synergy extracted by the NEX> NAD. To examine whether the individual muscle synergy was voluntarily activatable or not, we calculated the index of independent activation, which reflects similarities between a selected single muscle synergy and the current muscle activation pattern of the subject. Subjects were visually feed-backed the index of independent activation, then instructed to generate muscle activity patterns similar to the conventional and extended muscle synergies. As a result, an average of 90.8% of the muscle synergy extracted by the NVAF was independently activated. However, the proportion of activatable muscle synergies extracted by NCD and NAD was lower. These results partly support the assumption of the muscle synergy

  11. Muscle strength rather than muscle mass is associated with osteoporosis in older Chinese adults

    Directory of Open Access Journals (Sweden)

    Yixuan Ma

    2018-02-01

    Conclusion: Based on our study, muscle strength rather than muscle mass is negatively associated with OS in older people; thus, we should pay more attention to muscle strength training in the early stage of the OS.

  12. RETARDATION OF MUSCLE GROWTH IN CASTRATED MALE MICE:

    African Journals Online (AJOL)

    the absolute weights and the muscle mass indices of the muscles of castrated males were ... Muscles, Mice. INTRODUCTION rat levator ani muscles. It was noted that the hypertrophy of the muscle was a result. Muscles of adult male mice are invariably of increase in myofibrilar material .... (1976): Skeletal muscle cellularity.

  13. Inspiratory muscle training attenuates the human respiratory muscle metaboreflex

    Science.gov (United States)

    Witt, Jonathan D; Guenette, Jordan A; Rupert, Jim L; McKenzie, Donald C; Sheel, A William

    2007-01-01

    We hypothesized that inspiratory muscle training (IMT) would attenuate the sympathetically mediated heart rate (HR) and mean arterial pressure (MAP) increases normally observed during fatiguing inspiratory muscle work. An experimental group (Exp, n = 8) performed IMT 6 days per week for 5 weeks at 50% of maximal inspiratory pressure (MIP), while a control group (Sham, n = 8) performed IMT at 10% MIP. Pre- and post-training, subjects underwent a eucapnic resistive breathing task (RBT) (breathing frequency = 15 breaths min−1, duty cycle = 0.70) while HR and MAP were continuously monitored. Following IMT, MIP increased significantly (P inspiratory work. We attribute our findings to a reduced activity of chemosensitive afferents within the inspiratory muscles and may provide a mechanism for some of the whole-body exercise endurance improvements associated with IMT. PMID:17855758

  14. Inspiratory muscle training for asthma.

    Science.gov (United States)

    Silva, Ivanizia S; Fregonezi, Guilherme A F; Dias, Fernando A L; Ribeiro, Cibele T D; Guerra, Ricardo O; Ferreira, Gardenia M H

    2013-09-08

    In some people with asthma, expiratory airflow limitation, premature closure of small airways, activity of inspiratory muscles at the end of expiration and reduced pulmonary compliance may lead to lung hyperinflation. With the increase in lung volume, chest wall geometry is modified, shortening the inspiratory muscles and leaving them at a sub-optimal position in their length-tension relationship. Thus, the capacity of these muscles to generate tension is reduced. An increase in cross-sectional area of the inspiratory muscles caused by hypertrophy could offset the functional weakening induced by hyperinflation. Previous studies have shown that inspiratory muscle training promotes diaphragm hypertrophy in healthy people and patients with chronic heart failure, and increases the proportion of type I fibres and the size of type II fibres of the external intercostal muscles in patients with chronic obstructive pulmonary disease. However, its effects on clinical outcomes in patients with asthma are unclear. To evaluate the efficacy of inspiratory muscle training with either an external resistive device or threshold loading in people with asthma. We searched the Cochrane Airways Group Specialised Register of trials, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov and reference lists of included studies. The latest search was performed in November 2012. We included randomised controlled trials that involved the use of an external inspiratory muscle training device versus a control (sham or no inspiratory training device) in people with stable asthma. We used standard methodological procedures expected by The Cochrane Collaboration. We included five studies involving 113 adults. Participants in four studies had mild to moderate asthma and the fifth study included participants independent of their asthma severity. There were substantial differences between the studies, including the training protocol, duration of training sessions (10 to 30

  15. Laughing: a demanding exercise for trunk muscles.

    Science.gov (United States)

    Wagner, Heiko; Rehmes, Ulrich; Kohle, Daniel; Puta, Christian

    2014-01-01

    Social, psychological, and physiological studies have provided evidence indicating that laughter imposes an increased demand on trunk muscles. It was the aim of this study to quantify the activation of trunk muscles during laughter yoga in comparison with crunch and back lifting exercises regarding the mean trunk muscle activity. Muscular activity during laughter yoga exercises was measured by surface electromyography of 5 trunk muscles. The activation level of internal oblique muscle during laughter yoga is higher compared to the traditional exercises. The multifidus, erector spinae, and rectus abdominis muscles were nearly half activated during laughter yoga, while the activation of the external oblique muscle was comparable with the crunch and back lifting exercises. Our results indicate that laughter yoga has a positive effect on trunk muscle activation. Thus, laughter seems to be a good activator of trunk muscles, but further research is required whether laughter yoga is a good exercise to improve neuromuscular recruitment patterns for spine stability.

  16. Striated Muscle Function, Regeneration, and Repair

    Science.gov (United States)

    Shadrin, I.Y.; Khodabukus, A.; Bursac, N.

    2016-01-01

    As the only striated muscle tissues in the body, skeletal and cardiac muscle share numerous structural and functional characteristics, while exhibiting vastly different size and regenerative potential. Healthy skeletal muscle harbors a robust regenerative response that becomes inadequate after large muscle loss or in degenerative pathologies and aging. In contrast, the mammalian heart loses its regenerative capacity shortly after birth, leaving it susceptible to permanent damage by acute injury or chronic disease. In this review, we compare and contrast the physiology and regenerative potential of native skeletal and cardiac muscles, mechanisms underlying striated muscle dysfunction, and bioengineering strategies to treat muscle disorders. We focus on different sources for cellular therapy, biomaterials to augment the endogenous regenerative response, and progress in engineering and application of mature striated muscle tissues in vitro and in vivo. Finally, we discuss the challenges and perspectives in translating muscle bioengineering strategies to clinical practice. PMID:27271751

  17. Nuclear Positioning in Muscle Development and Disease

    Directory of Open Access Journals (Sweden)

    Eric eFolker

    2013-12-01

    Full Text Available Muscle disease as a group is characterized by muscle weakness, muscle loss, and impaired muscle function. Although the phenotype is the same, the underlying cellular pathologies, and the molecular causes of these pathologies, are diverse. One common feature of many muscle disorders is the mispositioning of myonuclei. In unaffected individuals myonuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, the nuclei are often clustered within the center of the muscle cell. Although this phenotype has been acknowledged for several decades, it is often ignored as a contributor to muscle weakness. Rather, these nuclei are taken only as a sign of muscle repair. Here we review the evidence that mispositioned myonuclei are not merely a symptom of muscle disease but also a cause. Additionally, we review the working models for how myonuclei move from two different perspectives, from that of the nucleus and from that of the cytoskeleton. We further compare and contrast these mechanisms with the mechanisms of nuclear movement in other cell types both to draw general themes for nuclear movement and to identify muscle-specific considerations. Finally, we focus on factors that can be linked to muscle disease and find that genes that regulate myonuclear movement and positioning have been linked to muscular dystrophy. Although the cause-effect relationship is largely speculative, recent data indicate that the position of nuclei should no longer be considered only a means to diagnose muscle disease.

  18. Diagnosis of skeletal muscle channelopathies.

    Science.gov (United States)

    Spillane, Jennifer; Fialho, Doreen; Hanna, Michael G

    2013-11-01

    Skeletal muscle channelopathies are rare disorders of muscle membrane excitability. Their episodic nature may result in diagnostic difficulty and delays in diagnosis. Advances in diagnostic clinical electrophysiology combined with DNA-based diagnosis have improved diagnostic accuracy and efficiency. Ascribing pathogenic status to identified genetic variants in muscle channel genes may be complex and functional analysis, including molecular expression, may help with this. Accurate clinical and genetic diagnosis enables genetic counselling, advice regarding prognosis and aids treatment selection. An approach to accurate and efficient diagnosis is outlined. The importance of detailed clinical evaluation including careful history, examination and family history is emphasised. The role of specialised electrodiagnostics combined with DNA testing and molecular expression is considered. New potential biomarkers including muscle MRI using MRC Centre protocols are discussed. A combined diagnostic approach using careful clinical assessment, specialised neurophysiology and DNA testing will now achieve a clear diagnosis in most patients with muscle channelopathies. An accurate diagnosis enables genetic counselling and provides information regarding prognosis and treatment selection. Genetic analysis often identifies new variants of uncertain significance. In this situation, functional expression studies as part of a diagnostic service will enable determination of pathogenic status of novel genetic variants.

  19. Muscle channelopathies and related diseases.

    Science.gov (United States)

    Fontaine, Bertrand

    2013-01-01

    Muscle channelopathies and related disorders are neuromuscular disorders predominantly of genetic origin which are caused by mutations in ion channels or genes that play a role in muscle excitability. They include different forms of periodic paralysis which are characterized by acute and reversible attacks of muscle weakness concomitant to changes in blood potassium levels. These disorders may also present as distinguishable myotonic syndromes (slowed muscle relaxation) which have in common lack of involvement of dystrophic changes of the muscle, in contrast to dystrophia myotonica. Recent advances have been made in the diagnosis of these different disorders, which require, in addition to a careful clinical evaluation, detailed EMG and molecular study. Although these diseases are rare, they deserve attention since patients may benefit from drugs which can dramatically improve their condition. Patients may have atypical presentations, sometimes life-threatening, which may delay a proper diagnosis, mostly in the first months of life. The creation of specialized reference centers in the Western world has greatly benefited the proper recognition of these neuromuscular diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. The Skeletal Muscle Satellite Cell

    Science.gov (United States)

    2011-01-01

    The skeletal muscle satellite cell was first described and named based on its anatomic location between the myofiber plasma and basement membranes. In 1961, two independent studies by Alexander Mauro and Bernard Katz provided the first electron microscopic descriptions of satellite cells in frog and rat muscles. These cells were soon detected in other vertebrates and acquired candidacy as the source of myogenic cells needed for myofiber growth and repair throughout life. Cultures of isolated myofibers and, subsequently, transplantation of single myofibers demonstrated that satellite cells were myogenic progenitors. More recently, satellite cells were redefined as myogenic stem cells given their ability to self-renew in addition to producing differentiated progeny. Identification of distinctively expressed molecular markers, in particular Pax7, has facilitated detection of satellite cells using light microscopy. Notwithstanding the remarkable progress made since the discovery of satellite cells, researchers have looked for alternative cells with myogenic capacity that can potentially be used for whole body cell-based therapy of skeletal muscle. Yet, new studies show that inducible ablation of satellite cells in adult muscle impairs myofiber regeneration. Thus, on the 50th anniversary since its discovery, the satellite cell’s indispensable role in muscle repair has been reaffirmed. PMID:22147605

  1. A further observation of muscle spindles in the extensor digitorum longus muscle of the aged rat.

    Science.gov (United States)

    Desaki, Junzo; Nishida, Naoya

    2010-01-01

    We observed three novel muscle spindles in the extensor digitorum longus muscle of the aged (20 months) rat. Two muscle spindles of the three contained thin muscle fibers lacking sensory innervation between the layers of the spindle capsule and within the periaxial space, respectively. The other one contained sensory-innervated thin muscle fibers with an indistinct equatorial nucleation between the layers of the spindle capsule. These findings suggest that the occurrence of thin muscle fibers may be intimately related to the degeneration and regeneration of extrafusal muscle fibers during aging and that these newly formed thin muscle fibers may often fail to receive sensory innervation.

  2. Regeneration of muscle fibers in the extensor digitorum longus muscle of the aged rat.

    Science.gov (United States)

    Desaki, Junzo

    2008-04-01

    Regeneration of muscle fibers was observed in the extensor digitorum longus (EDL) muscle of aged (24 and 27 months) Wistar rats. The aged muscles consisted almost exclusively of medium-sized muscle fibers. In addition to degenerating and/or atrophied muscle fibers, very small muscle fibers <10 mum in diameter were observed in some muscle bundles which sporadically distributed in the muscle. In the degenerating muscle fibers, satellite cells mostly appeared to be normal, possibly surviving within the scaffold of basal lamina to form new (regenerating) muscle fibers. However, some of the satellite cells were degenerated and destroyed, suggesting the decrease in number of muscle fibers. On the other hand, very small muscle fibers existed between small and/or medium-sized muscle fibers or in the wide interstitial spaces between them solitarily or in small groups. In addition, immature muscle cells having a centrally located nucleus and sporadically distributed myofilaments were observed among the small and/or medium-sized muscle fibers and partially lacked a layer of basal lamina. These immature muscle cells were often closely apposed to fibroblasts with some slender cytoplasmic processes and/or to each other without an interposing basal lamina. These findings suggest that in addition to satellite cells within the basal lamina tubes, some of the regenerating muscle fibers in the aged EDL muscle may be originated from mesenchymal cells such as fibroblasts in the interstitial spaces.

  3. Evaluation of muscle function of the extensor digitorum longus muscle ex vivo and tibialis anterior muscle in situ in mice.

    Science.gov (United States)

    Hakim, Chady H; Wasala, Nalinda B; Duan, Dongsheng

    2013-02-09

    Body movements are mainly provided by mechanical function of skeletal muscle. Skeletal muscle is composed of numerous bundles of myofibers that are sheathed by intramuscular connective tissues. Each myofiber contains many myofibrils that run longitudinally along the length of the myofiber. Myofibrils are the contractile apparatus of muscle and they are composed of repeated contractile units known as sarcomeres. A sarcomere unit contains actin and myosin filaments that are spaced by the Z discs and titin protein. Mechanical function of skeletal muscle is defined by the contractile and passive properties of muscle. The contractile properties are used to characterize the amount of force generated during muscle contraction, time of force generation and time of muscle relaxation. Any factor that affects muscle contraction (such as interaction between actin and myosin filaments, homeostasis of calcium, ATP/ADP ratio, etc.) influences the contractile properties. The passive properties refer to the elastic and viscous properties (stiffness and viscosity) of the muscle in the absence of contraction. These properties are determined by the extracellular and the intracellular structural components (such as titin) and connective tissues (mainly collagen) (1-2). The contractile and passive properties are two inseparable aspects of muscle function. For example, elbow flexion is accomplished by contraction of muscles in the anterior compartment of the upper arm and passive stretch of muscles in the posterior compartment of the upper arm. To truly understand muscle function, both contractile and passive properties should be studied. The contractile and/or passive mechanical properties of muscle are often compromised in muscle diseases. A good example is Duchenne muscular dystrophy (DMD), a severe muscle wasting disease caused by dystrophin deficiency (3). Dystrophin is a cytoskeletal protein that stabilizes the muscle cell membrane (sarcolemma) during muscle contraction (4). In the

  4. Exercise Promotes Healthy Aging of Skeletal Muscle

    Science.gov (United States)

    Cartee, Gregory D.; Hepple, Russell T.; Bamman, Marcas M.; Zierath, Juleen R.

    2016-01-01

    Primary aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics, and reduced muscle mass. Secondary aging refers to additional deleterious structural and functional age-related changes caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes “healthy aging” by inducing modifications in skeletal muscle. PMID:27304505

  5. Partial muscle carnitine palmitoyltransferase-A deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Ross, N.S.; Hoppel, C.L.

    1987-01-02

    After initiation of ibuprofen therapy, a 45-year-old woman developed muscle weakness and tenderness with rhabdomyolysis, culminating in respiratory failure. A muscle biopsy specimen showed a vacuolar myopathy, and markedly decreased muscle carnitine content and carnitine palmitoyltransferase activity. Following recovery, muscle carnitine content was normal but carnitine palmitoyltransferase activity was still abnormally low. The ratio of palmitoyl-coenzyme A plus carnitine to palmitoylcarnitine oxidation by muscle mitochondria isolated from the patient was markedly decreased. The authors conclude that transiently decreased muscle carnitine content interacted with partial deficiency of carnitine palmitoyltransferase-A to produce rhabdomyolysis and respiratory failure and that ibuprofen may have precipitated the clinical event.

  6. Partial muscle carnitine palmitoyltransferase-A deficiency

    International Nuclear Information System (INIS)

    Ross, N.S.; Hoppel, C.L.

    1987-01-01

    After initiation of ibuprofen therapy, a 45-year-old woman developed muscle weakness and tenderness with rhabdomyolysis, culminating in respiratory failure. A muscle biopsy specimen showed a vacuolar myopathy, and markedly decreased muscle carnitine content and carnitine palmitoyltransferase activity. Following recovery, muscle carnitine content was normal but carnitine palmitoyltransferase activity was still abnormally low. The ratio of palmitoyl-coenzyme A plus carnitine to palmitoylcarnitine oxidation by muscle mitochondria isolated from the patient was markedly decreased. The authors conclude that transiently decreased muscle carnitine content interacted with partial deficiency of carnitine palmitoyltransferase-A to produce rhabdomyolysis and respiratory failure and that ibuprofen may have precipitated the clinical event

  7. Vitamin D and muscle function.

    Science.gov (United States)

    Dawson-Hughes, Bess

    2017-10-01

    Muscle weakness is a hallmark of severe vitamin D deficiency, but the effect of milder vitamin D deficiency or insufficiency on muscle mass and performance and risk of falling is uncertain. In this presentation, I review the evidence that vitamin D influences muscle mass and performance, balance, and risk of falling in older adults. Special consideration is given to the impact of both the starting 25-hydroxyvitamin D [25(OH)D] level and the dose administered on the clinical response to supplemental vitamin D in older men and women. Based on available evidence, older adults with serum 25(OH)D levels vitamin D dose range of 800-1000 IU per day has been effective in many studies; lower doses have generally been ineffective and several doses above this range have increased the risk of falls. In conclusion, older adults with serum 25(OH)D levels vitamin D. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The arrangement of muscle fibers and tendons in two muscles used for growth studies.

    Science.gov (United States)

    Stickland, N C

    1983-01-01

    The arrangement of muscle fibres and tendons was examined in the soleus muscle of rats from 6 to 175 days post partum. The muscle was seen to change from a simple structure, with mean fibre length of approximately 90% of complete muscle length, to a unipennate structure, with mean fibre length of only about 60% of muscle length. The dog pectineus muscle was also investigated and found to have a bipennate structure throughout postnatal growth. The arrangement of muscle fibres in both these muscles is such that it might be difficult (particularly in the older animals) to cut a transverse section through all the fibres contained in the muscle; some fibres might not enter the plane of section. Results on muscle fibre number in these muscles at different ages may therefore be misleading.

  9. Muscle cramps in liver disease.

    Science.gov (United States)

    Mehta, Shivang S; Fallon, Michael B

    2013-11-01

    Muscle cramps are common in patients with liver disease and adversely influence quality of life. The exact mechanisms by which they occur remain unclear, although a number of pathophysiological events unique to liver disease may contribute. Clinical studies have identified alterations in 3 areas: nerve function, energy metabolism, and plasma volume/electrolytes. Treatments have focused on these particular areas with varied results. This review will focus on the clinical features of muscle cramps in patients with liver disease and review potential mechanisms and current therapies. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

  10. Muscle after spinal cord injury

    DEFF Research Database (Denmark)

    Biering-Sørensen, Bo; Kristensen, Ida Bruun; Kjaer, Michael

    2009-01-01

    The morphological and contractile changes of muscles below the level of the lesion after spinal cord injury (SCI) are dramatic. In humans with SCI, a fiber-type transformation away from type I begins 4-7 months post-SCI and reaches a new steady state with predominantly fast glycolytic IIX fibers...... years after the injury. There is a progressive drop in the proportion of slow myosin heavy chain (MHC) isoform fibers and a rise in the proportion of fibers that coexpress both the fast and slow MHC isoforms. The oxidative enzymatic activity starts to decline after the first few months post-SCI. Muscles...

  11. Muscle glycogen stores and fatigue

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Westerblad, Håkan; Nielsen, Joachim

    2013-01-01

    function during fatigue is not well understood and a direct cause-and-effect relationship between glycogen and muscle function remains to be established. The use of electron microscopy has revealed that glycogen is not homogeneously distributed in skeletal muscle fibres, but rather localized in distinct...... the sarcoplasmic reticulum (SR). We and others have provided experimental evidence in favour of a direct role of decreased glycogen, localized within the myofibrils, for the reduction in SR Ca2+ release during fatigue. This is consistent with compartmentalized energy turnover and distinctly localized glycogen...

  12. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  13. Muscle phosphoglycerate mutase deficiency revisited

    DEFF Research Database (Denmark)

    Naini, Ali; Toscano, Antonio; Musumeci, Olimpia

    2009-01-01

    storage disease type X and novel mutations in the gene encoding the muscle subunit of PGAM (PGAM2). DESIGN: Clinical, pathological, biochemical, and molecular analyses. SETTING: Tertiary care university hospitals and academic institutions. Patients A 37-year-old Danish man of Pakistani origin who had...... PGAM deficiency, and molecular studies revealed 2 novel homozygous mutations, a nonsense mutation and a single nucleotide deletion. Pathological studies of muscle showed mild glycogen accumulation but prominent tubular aggregates in both patients. CONCLUSIONS: We found that glycogen storage disease...

  14. Neural effects of muscle stretching on the spinal reflexes in multiple lower-limb muscles.

    Science.gov (United States)

    Masugi, Yohei; Obata, Hiroki; Inoue, Daisuke; Kawashima, Noritaka; Nakazawa, Kimitaka

    2017-01-01

    While previous studies have shown that muscle stretching suppresses monosynaptic spinal reflex excitability in stretched muscles, its effects on non-stretched muscles is still largely unknown. The purpose of this study was to examine the effects of muscle stretching on monosynaptic spinal reflex in non-stretched muscles. Ten healthy male subjects participated in this study. Muscle stretching of the right triceps surae muscle was performed using a motor torque device for 1 minute. Three different dorsiflexion torques (at approximately 5, 10, and 15 Nm) were applied during muscle stretching. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded in both the lower-limb muscles before, during, and at 0 and 5 min following muscle stretching. The amplitudes of the spinal reflexes in both the stretched and non-stretched muscles in the right (ipsilateral) leg were smaller during stretching compared to before, and at 0 and 5 min after stretching. Furthermore, the degree of reduction in the amplitude of the spinal reflexes in the right (ipsilateral) leg muscles increased significantly as the dorsiflexion torque (i.e., stretching of the right triceps surae muscles) increased. In contrast, reduction in the amplitude of the spinal reflexes with increasing dorsiflexion torque was not seen in the left (contralateral) leg muscles. Our results clearly indicate that muscle stretching has inhibitory effects on monosynaptic spinal reflexes, not only in stretched muscles, but also in non-stretched muscles of the ipsilateral leg.

  15. 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.

  16. Role of Muscle Relaxant (Tizanidine) In Painful Muscle Spasm ...

    African Journals Online (AJOL)

    More prolonged or regular cramps may be treated with drugs. Tizanidine which is an agonist at á ... Inclusion criteria included all the patients suffering from painful muscle spasm in back, neck, shoulder, knee or other anatomical sites with onset not more than two days prior to presentation. The patients suffering from ...

  17. Myofascial force transmisison between antagonistic rat lower limb muscles: effects of single muscle or muscle group lengthening

    NARCIS (Netherlands)

    Meijer, Hanneke J.M; Rijkelijkhuizen, Josina M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  18. Myofascial force transmission between antagonistic rat lower limb muscles: Effects of single muscle or muscle group lengthening.

    NARCIS (Netherlands)

    Meijer, H.J.M.; Rijkelijkhuizen, J.M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  19. Bones, Muscles, and Joints: The Musculoskeletal System

    Science.gov (United States)

    ... Skeletal muscles are called striated (pronounced: STRY-ay-ted) because they are made up of fibers that ... blood through your body. When we smile and talk, muscles are helping us communicate, and when we ...

  20. Measurement and Treatment of Passive Muscle Stiffness

    DEFF Research Database (Denmark)

    Kirk, Henrik

    This PhD thesis is based on research conducted at the University of Copenhagen and Helene Elsass Center from 2012 to 2015. Measurements and treatment of passive muscle stiffness in people with cerebral palsy (CP) comprise the focus of the thesis. The thesis summarizes the results from four studies......, which aimed to investigate: 1) The development of a clinical method to evaluate and distinguish neural (reflex mediated stiffness) and non-neural (passive muscle stiffness) components of muscle stiffness in adults with CP by objective and reliable measurements. 2) The association between increased...... passive muscle, muscle strength and gait function in adults with CP 3) The effect of resistance training and gait training accordingly on muscle strength, passive muscle stiffness and functional gait in adults with CP. The first part of the thesis defines reflex mediated stiffness and passive muscle...

  1. Magnetic resonance imaging of facial muscles

    Energy Technology Data Exchange (ETDEWEB)

    Farrugia, M.E. [Department of Clinical Neurology, University of Oxford, Radcliffe Infirmary, Oxford (United Kingdom)], E-mail: m.e.farrugia@doctors.org.uk; Bydder, G.M. [Department of Radiology, University of California, San Diego, CA 92103-8226 (United States); Francis, J.M.; Robson, M.D. [OCMR, Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford (United Kingdom)

    2007-11-15

    Facial and tongue muscles are commonly involved in patients with neuromuscular disorders. However, these muscles are not as easily accessible for biopsy and pathological examination as limb muscles. We have previously investigated myasthenia gravis patients with MuSK antibodies for facial and tongue muscle atrophy using different magnetic resonance imaging sequences, including ultrashort echo time techniques and image analysis tools that allowed us to obtain quantitative assessments of facial muscles. This imaging study had shown that facial muscle measurement is possible and that useful information can be obtained using a quantitative approach. In this paper we aim to review in detail the methods that we applied to our study, to enable clinicians to study these muscles within the domain of neuromuscular disease, oncological or head and neck specialties. Quantitative assessment of the facial musculature may be of value in improving the understanding of pathological processes occurring within facial muscles in certain neuromuscular disorders.

  2. Cardiac, Skeletal, and smooth muscle mitochondrial respiration

    DEFF Research Database (Denmark)

    Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I

    2014-01-01

    in cardiac, skeletal, and smooth muscle suggest all mitochondria are created equal, the contrasting RCR and non-phosphorylating respiration highlight the existence of intrinsic functional differences between these muscle mitochondria. This likely influences the efficiency of oxidative phosphorylation...

  3. The characteristics of a pneumatic muscle

    Directory of Open Access Journals (Sweden)

    Pietrala Dawid

    2017-01-01

    Full Text Available The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics. It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics. It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics. The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  4. The characteristics of a pneumatic muscle

    Science.gov (United States)

    Pietrala, Dawid

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics). It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics). The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  5. Magnetic resonance imaging of facial muscles

    International Nuclear Information System (INIS)

    Farrugia, M.E.; Bydder, G.M.; Francis, J.M.; Robson, M.D.

    2007-01-01

    Facial and tongue muscles are commonly involved in patients with neuromuscular disorders. However, these muscles are not as easily accessible for biopsy and pathological examination as limb muscles. We have previously investigated myasthenia gravis patients with MuSK antibodies for facial and tongue muscle atrophy using different magnetic resonance imaging sequences, including ultrashort echo time techniques and image analysis tools that allowed us to obtain quantitative assessments of facial muscles. This imaging study had shown that facial muscle measurement is possible and that useful information can be obtained using a quantitative approach. In this paper we aim to review in detail the methods that we applied to our study, to enable clinicians to study these muscles within the domain of neuromuscular disease, oncological or head and neck specialties. Quantitative assessment of the facial musculature may be of value in improving the understanding of pathological processes occurring within facial muscles in certain neuromuscular disorders

  6. Surgical Anatomy of the Radial Nerve at the Elbow and in the Forearm: Anatomical Basis for Intraplexus Nerve Transfer to Reconstruct Thumb and Finger Extension in C7 - T1 Brachial Plexus Palsy.

    Science.gov (United States)

    Zhang, Lei; Dong, Zhen; Zhang, Chun-Lin; Gu, Yu-Dong

    2016-11-01

    Background  C7 - T1 palsy results in complete loss of finger motion and poses a surgical challenge. This study investigated the anatomy of the radial nerve in the elbow and forearm and the feasibility of intraplexus nerve transfer to restore thumb and finger extension. Methods  The radial nerves were dissected in 28 formalin-fixed upper extremities. Branching pattern, length, diameter, and number of myelinated fibers were recorded. Results  Commonly, the branching pattern (from proximal to distal) was to the brachioradialis, extensor carpi radialis longus, superficial sensory proximal to the lateral epicondyle, extensor carpi radialis brevis, supinator, extensor digitorum communis, extensor digiti minimi, extensor carpi ulnaris, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, and extensor indicis distal to the lateral epicondyle. Conclusions  Branches to the brachioradialis, extensor carpi radialis longus, and supinator can be transferred to the posterior interosseous nerve to restore hand movement in patients with C7 - T1 brachial plexus palsies; the supinator branch is probably the best choice in this regard. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  7. Study on distribution of terminal branches of the facial nerve in mimetic muscles (orbicularis oculi muscle and orbicularis oris muscle).

    Science.gov (United States)

    Mitsukawa, Nobuyuki; Moriyama, Hiroshi; Shiozawa, Kei; Satoh, Kaneshige

    2014-01-01

    There have been many anatomical reports to date regarding the course of the facial nerve to the mimetic muscles. However, reports are relatively scarce on the detailed distribution of the terminal branches of the facial nerve to the mimetic muscles. In this study, we performed detailed examination of the terminal facial nerve branches to the mimetic muscles, particularly the branches terminating in the orbicularis oculi muscle and orbicularis oris muscle. Examination was performed on 25 Japanese adult autopsy cases, involving 25 hemifaces. The mean age was 87.4 years (range, 60-102 years). There were 12 men and 13 women (12 left hemifaces and 13 right hemifaces). In each case, the facial nerve was exposed through a preauricular skin incision. The main trunk of the facial nerve was dissected from the stylomastoid foramen. A microscope was used to dissect the terminal branches to the periphery and observe them. The course and distribution were examined for all terminal branches of the facial nerve. However, focus was placed on the course and distribution of the zygomatic branch, buccal branch, and mandibular branch to the orbicularis oculi muscle and orbicularis oris muscle. The temporal branch was distributed to the orbicularis oculi muscle in all cases and the marginal mandibular branch was distributed to the orbicularis oris muscle in all cases. The zygomatic branch was distributed to the orbicularis oculi muscle in all cases, but it was also distributed to the orbicularis oris muscle in 10 of 25 cases. The buccal branch was not distributed to the orbicularis oris muscle in 3 of 25 cases, and it was distributed to the orbicularis oculi muscle in 8 cases. There was no significant difference in the variations. The orbicularis oculi muscle and orbicularis oris muscle perform particularly important movements among the facial mimetic muscles. According to textbooks, the temporal branch and zygomatic branch innervate the orbicularis oculi muscle, and the buccal branch

  8. Exercise Promotes Healthy Aging of Skeletal Muscle

    DEFF Research Database (Denmark)

    Cartee, Gregory D; Hepple, Russell T; Bamman, Marcas M

    2016-01-01

    caused by diseases and lifestyle factors. Secondary aging can exacerbate deficits in mitochondrial function and muscle mass, concomitant with the development of skeletal muscle insulin resistance. Exercise opposes deleterious effects of secondary aging by preventing the decline in mitochondrial...... respiration, mitigating aging-related loss of muscle mass and enhancing insulin sensitivity. This review focuses on mechanisms by which exercise promotes "healthy aging" by inducing modifications in skeletal muscle....

  9. Muscle fatigue: general understanding and treatment

    Science.gov (United States)

    Wan, Jing-jing; Qin, Zhen; Wang, Peng-yuan; Sun, Yang; Liu, Xia

    2017-01-01

    Muscle fatigue is a common complaint in clinical practice. In humans, muscle fatigue can be defined as exercise-induced decrease in the ability to produce force. Here, to provide a general understanding and describe potential therapies for muscle fatigue, we summarize studies on muscle fatigue, including topics such as the sequence of events observed during force production, in vivo fatigue-site evaluation techniques, diagnostic markers and non-specific but effective treatments. PMID:28983090

  10. Muscle fatigue: general understanding and treatment

    OpenAIRE

    Wan, Jing-jing; Qin, Zhen; Wang, Peng-yuan; Sun, Yang; Liu, Xia

    2017-01-01

    Muscle fatigue is a common complaint in clinical practice. In humans, muscle fatigue can be defined as exercise-induced decrease in the ability to produce force. Here, to provide a general understanding and describe potential therapies for muscle fatigue, we summarize studies on muscle fatigue, including topics such as the sequence of events observed during force production, in vivo fatigue-site evaluation techniques, diagnostic markers and non-specific but effective treatments.

  11. Muscle Selection for Focal Limb Dystonia

    OpenAIRE

    Barbara Illowsky Karp; Katharine Alter

    2017-01-01

    Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this artic...

  12. The characteristics of a pneumatic muscle

    OpenAIRE

    Pietrala Dawid

    2017-01-01

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles s...

  13. STRUCTURAL ALTERATIONS OF SKELETAL MUSCLE IN COPD

    Directory of Open Access Journals (Sweden)

    Sunita eMathur

    2014-03-01

    Full Text Available Background: Chronic obstructive pulmonary disease (COPD is a respiratory disease associated with a systemic inflammatory response. Peripheral muscle dysfunction has been well characterized in individuals with COPD and results from a complex interaction between systemic and local factors. Objective: In this narrative review, we will describe muscle wasting in people with COPD, the associated structural changes, muscle regenerative capacity and possible mechanisms for muscle wasting. We will also discuss how structural changes relate to impaired muscle function and mobility in people with COPD. Key Observations: Approximately 30-40% of individuals with COPD experience muscle mass depletion. Furthermore, muscle atrophy is a predictor of physical function and mortality in this population. Associated structural changes include a decreased proportion and size of type-I fibers, reduced oxidative capacity and mitochondrial density mainly in the quadriceps. Observations related to impaired muscle regenerative capacity in individuals with COPD include a lower proportion of central nuclei in the presence or absence of muscle atrophy and decreased maximal telomere length, which has been correlated with reduced muscle cross-sectional area. Potential mechanisms for muscle wasting in COPD may include excessive production of reactive oxygen species, altered amino acid metabolism and lower expression of peroxisome proliferator-activated receptors-gamma-coactivator 1-alpha mRNA. Despite a moderate relationship between muscle atrophy and function, impairments in oxidative metabolism only seems weakly related to muscle function. Conclusion: This review article demonstrates the cellular modifications in the peripheral muscle of people with COPD and describes the evidence of its relationship to muscle function. Future research will focus on rehabilitation strategies to improve muscle wasting and maximize function.

  14. Muscle mechanics and neuromuscular control

    NARCIS (Netherlands)

    Hof, AL

    The purpose of this paper is to demonstrate that the properties of the mechanical system, especially muscle elasticity and limb mass, to a large degree determine force output and movement. This makes the control demands of the central nervous system simpler and more robust. In human triceps surae, a

  15. Aging of Skeletal Muscle Fibers

    Science.gov (United States)

    Miljkovic, Natasa; Lim, Jae-Young; Miljkovic, Iva

    2015-01-01

    Aging has become an important topic for scientific research because life expectancy and the number of men and women in older age groups have increased dramatically in the last century. This is true in most countries of the world including the Republic of Korea and the United States. From a rehabilitation perspective, the most important associated issue is a progressive decline in functional capacity and independence. Sarcopenia is partly responsible for this decline. Many changes underlying the loss of muscle mass and force-generating capacity of skeletal muscle can be understood at the cellular and molecular levels. Muscle size and architecture are both altered with advanced adult age. Further, changes in myofibers include impairments in several physiological domains including muscle fiber activation, excitation-contraction coupling, actin-myosin cross-bridge interaction, energy production, and repair and regeneration. A thorough understanding of these alterations can lead to the design of improved preventative and rehabilitative interventions, such as personalized exercise training programs. PMID:25932410

  16. Evaluation of isokinetic muscle performance.

    Science.gov (United States)

    Watkins, M P; Harris, B A

    1983-03-01

    The development and availability of isokinetic testing equipment, recording systems, and systems for computer analysis have improved the quality and quantity of information about specific skeletal muscle performance. The value of both isokinetic exercise and instrumentation designed to objectively record muscle performance characteristics is becoming more widely recognized, especially by professional members of the sports medicine community. The present demand for appropriate equipment is high and new instrumentation for this purpose is being developed. Current instrumentation continues to be modified and improved. The information gained from carefully designed testing protocols is useful and necessary for understanding the role of specific muscle groups in athletic performance and for determining the readiness of the athlete to resume training or competition following injury or deconditioning. With expanded profile data about the muscle performance characteristics of various categories of athletes, training or rehabilitation programs may be adapted to meet the strength, speed, and endurance requirements of a given sport, which may enhance the quality of participation and prevent the occurrence of injury or reinjury.

  17. Excitation of Mytilus smooth muscle.

    Science.gov (United States)

    Twarog, B M

    1967-10-01

    1. Membrane potentials and tension were recorded during nerve stimulation and direct stimulation of smooth muscle cells of the anterior byssus retractor muscle of Mytilus edulis L.2. The resting potential averaged 65 mV (range 55-72 mV).3. Junction potentials reached 25 mV and decayed to one half maximum amplitude in 500 msec. Spatial summation and facilitation of junction potentials were observed.4. Action potentials, 50 msec in duration and up to 50 mV in amplitude were fired at a membrane potential of 35-40 mV. No overshoot was observed.5. Contraction in response to neural stimulation was associated with spike discharge. Measurement of tension and depolarization in muscle bundles at high K(+) indicated that tension is only produced at membrane potentials similar to those achieved by spike discharge.6. Blocking of junction potentials, spike discharge and contraction by methantheline, an acetylcholine antagonist, supports the hypothesis that the muscle is excited by cholinergic nerves. However, evidence of a presynaptic action of methantheline complicates this argument.

  18. Novel Analog For Muscle Deconditioning

    Science.gov (United States)

    Ploutz-Snyder, Lori; Ryder, Jeff; Buxton, Roxanne; Redd. Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle; Fiedler, James; Ploutz-Snyder, Robert; Bloomberg, Jacob

    2011-01-01

    Existing models (such as bed rest) of muscle deconditioning are cumbersome and expensive. We propose a new model utilizing a weighted suit to manipulate strength, power, or endurance (function) relative to body weight (BW). Methods: 20 subjects performed 7 occupational astronaut tasks while wearing a suit weighted with 0-120% of BW. Models of the full relationship between muscle function/BW and task completion time were developed using fractional polynomial regression and verified by the addition of pre-and postflightastronaut performance data for the same tasks. Splineregression was used to identify muscle function thresholds below which task performance was impaired. Results: Thresholds of performance decline were identified for each task. Seated egress & walk (most difficult task) showed thresholds of leg press (LP) isometric peak force/BW of 18 N/kg, LP power/BW of 18 W/kg, LP work/BW of 79 J/kg, isokineticknee extension (KE)/BW of 6 Nm/kg, and KE torque/BW of 1.9 Nm/kg.Conclusions: Laboratory manipulation of relative strength has promise as an appropriate analog for spaceflight-induced loss of muscle function, for predicting occupational task performance and establishing operationally relevant strength thresholds.

  19. Muscle fatigue in fibromyalgia is in the brain, not in the muscles

    DEFF Research Database (Denmark)

    Bandak, Elisabeth; Amris, Kirstine; Bliddal, Henning

    2013-01-01

    To investigate relationships between perceived and objectively measured muscle fatigue during exhausting muscle contractions in women with fibromyalgia (FM) compared with healthy controls (HC).......To investigate relationships between perceived and objectively measured muscle fatigue during exhausting muscle contractions in women with fibromyalgia (FM) compared with healthy controls (HC)....

  20. Integrated expression analysis of muscle hypertrophy identifies Asb2 as a negative regulator of muscle mass

    Science.gov (United States)

    Davey, Jonathan R.; Watt, Kevin I.; Parker, Benjamin L.; Chaudhuri, Rima; Ryall, James G.; Cunningham, Louise; Qian, Hongwei; Sartorelli, Vittorio; Chamberlain, Jeffrey; James, David E.

    2016-01-01

    The transforming growth factor-β (TGF-β) signaling network is a critical regulator of skeletal muscle mass and function and, thus, is an attractive therapeutic target for combating muscle disease, but the underlying mechanisms of action remain undetermined. We report that follistatin-based interventions (which modulate TGF-β network activity) can promote muscle hypertrophy that ameliorates aging-associated muscle wasting. However, the muscles of old sarcopenic mice demonstrate reduced response to follistatin compared with healthy young-adult musculature. Quantitative proteomic and transcriptomic analyses of young-adult muscles identified a transcription/translation signature elicited by follistatin exposure, which included repression of ankyrin repeat and SOCS box protein 2 (Asb2). Increasing expression of ASB2 reduced muscle mass, thereby demonstrating that Asb2 is a TGF-β network–responsive negative regulator of muscle mass. In contrast to young-adult muscles, sarcopenic muscles do not exhibit reduced ASB2 abundance with follistatin exposure. Moreover, preventing repression of ASB2 in young-adult muscles diminished follistatin-induced muscle hypertrophy. These findings provide insight into the program of transcription and translation events governing follistatin-mediated adaptation of skeletal muscle attributes and identify Asb2 as a regulator of muscle mass implicated in the potential mechanistic dysfunction between follistatin-mediated muscle growth in young and old muscles. PMID:27182554

  1. Muscle strength in patients with chronic pain

    NARCIS (Netherlands)

    van Wilgen, C.P.; Akkerman, L.; Wieringa, J.; Dijkstra, P.U.

    2003-01-01

    Objective: To analyse the influence of chronic pain on muscle strength. Design: Muscle strength of patients with unilateral nonspecific chronic pain, in an upper or lower limb, were measured according to a standardized protocol using a hand-held dynamometer. Before and after muscle strength

  2. Mechanical modeling of skeletal muscle functioning

    NARCIS (Netherlands)

    van der Linden, B.J.J.J.

    1998-01-01

    For movement of body or body segments is combined effort needed of the central nervous system and the muscular-skeletal system. This thesis deals with the mechanical functioning of skeletal muscle. That muscles come in a large variety of geometries, suggest the existence of a relation between muscle

  3. Kinetics of glucose transport in rat muscle

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Galbo, Henrik; Vinten, Jørgen

    1987-01-01

    The effects of insulin and prior muscle contractions, respectively, on 3-O-methylglucose (3-O-MG) transport in skeletal muscle were studied in the perfused rat hindquarter. Initial rates of entry of 3-O-MG in red gastrocnemius, soleus, and white gastrocnemius muscles as a function of perfusate 3-O...

  4. Muscle MRI findings in facioscapulohumeral muscular dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Gerevini, Simonetta; Caliendo, Giandomenico; Falini, Andrea [IRCCS San Raffaele Scientific Institute, Neuroradiology Unit, Head and Neck Department, Milan (Italy); Scarlato, Marina; Previtali, Stefano Carlo [IRCCS San Raffaele Scientific Institute, Department of Neurology, INSPE and Division of Neuroscience, Milan (Italy); Maggi, Lorenzo; Pasanisi, Barbara; Morandi, Lucia [Fondazione IRCCS Istituto Neurologico ' ' Carlo Besta' ' , Neuromuscular Diseases and Neuroimmunology Unit, Milan (Italy); Cava, Mariangela [IRCCS San Raffaele Scientific Institute, Department of Radiology and Center for Experimental Imaging, Milan (Italy)

    2016-03-15

    Facioscapulohumeral muscular dystrophy (FSHD) is characterized by extremely variable degrees of facial, scapular and lower limb muscle involvement. Clinical and genetic determination can be difficult, as molecular analysis is not always definitive, and other similar muscle disorders may have overlapping clinical manifestations. Whole-body muscle MRI examination for fat infiltration, atrophy and oedema was performed to identify specific patterns of muscle involvement in FSHD patients (30 subjects), and compared to a group of control patients (23) affected by other myopathies (NFSHD). In FSHD patients, we detected a specific pattern of muscle fatty replacement and atrophy, particularly in upper girdle muscles. The most frequently affected muscles, including paucisymptomatic and severely affected FSHD patients, were trapezius, teres major and serratus anterior. Moreover, asymmetric muscle involvement was significantly higher in FSHD as compared to NFSHD patients. In conclusion, muscle MRI is very sensitive for identifying a specific pattern of involvement in FSHD patients and in detecting selective muscle involvement of non-clinically testable muscles. Muscle MRI constitutes a reliable tool for differentiating FSHD from other muscular dystrophies to direct diagnostic molecular analysis, as well as to investigate FSHD natural history and follow-up of the disease. (orig.)

  5. Exporting vector muscles for facial animation

    NARCIS (Netherlands)

    Bui, T.D.; Butz, Andreas; Kruger, Antonio; Heylen, Dirk K.J.; Olivier, Patrick; Nijholt, Antinus; Poel, Mannes

    2003-01-01

    In this paper we introduce a method of exporting vector muscles from one 3D face to another for facial animation. Starting from a 3D face with an extended version of Waters’ linear muscle system, we transfer the linear muscles to a target 3D face.We also transfer the region division, which is used

  6. Buckling Pneumatic Linear Actuators Inspired by Muscle

    OpenAIRE

    Yang, Dian; Verma, Mohit Singh; So, Ju-Hee; Mosadegh, Bobak; Keplinger, Christoph; Lee, Benjamin; Khashai, Fatemeh; Lossner, Elton Garret; Suo, Zhigang; Whitesides, George McClelland

    2016-01-01

    The mechanical features of biological muscles are difficult to reproduce completely in synthetic systems. A new class of soft pneumatic structures (vacuum-actuated muscle-inspired pneumatic structures) is described that combines actuation by negative pressure (vacuum), with cooperative buckling of beams fabricated in a slab of elastomer, to achieve motion and demonstrate many features that are similar to that of mammalian muscle.

  7. Redox Control of Skeletal Muscle Regeneration.

    Science.gov (United States)

    Le Moal, Emmeran; Pialoux, Vincent; Juban, Gaëtan; Groussard, Carole; Zouhal, Hassane; Chazaud, Bénédicte; Mounier, Rémi

    2017-08-10

    Skeletal muscle shows high plasticity in response to external demand. Moreover, adult skeletal muscle is capable of complete regeneration after injury, due to the properties of muscle stem cells (MuSCs), the satellite cells, which follow a tightly regulated myogenic program to generate both new myofibers and new MuSCs for further needs. Although reactive oxygen species (ROS) and reactive nitrogen species (RNS) have long been associated with skeletal muscle physiology, their implication in the cell and molecular processes at work during muscle regeneration is more recent. This review focuses on redox regulation during skeletal muscle regeneration. An overview of the basics of ROS/RNS and antioxidant chemistry and biology occurring in skeletal muscle is first provided. Then, the comprehensive knowledge on redox regulation of MuSCs and their surrounding cell partners (macrophages, endothelial cells) during skeletal muscle regeneration is presented in normal muscle and in specific physiological (exercise-induced muscle damage, aging) and pathological (muscular dystrophies) contexts. Recent advances in the comprehension of these processes has led to the development of therapeutic assays using antioxidant supplementation, which result in inconsistent efficiency, underlying the need for new tools that are aimed at precisely deciphering and targeting ROS networks. This review should provide an overall insight of the redox regulation of skeletal muscle regeneration while highlighting the limits of the use of nonspecific antioxidants to improve muscle function. Antioxid. Redox Signal. 27, 276-310.

  8. The arrangement of muscle fibers and tendons in two muscles used for growth studies.

    OpenAIRE

    Stickland, N C

    1983-01-01

    The arrangement of muscle fibres and tendons was examined in the soleus muscle of rats from 6 to 175 days post partum. The muscle was seen to change from a simple structure, with mean fibre length of approximately 90% of complete muscle length, to a unipennate structure, with mean fibre length of only about 60% of muscle length. The dog pectineus muscle was also investigated and found to have a bipennate structure throughout postnatal growth. The arrangement of muscle fibres in both these mus...

  9. Inspiratory muscle training in type 2 diabetes with inspiratory muscle weakness.

    Science.gov (United States)

    Corrêa, Ana Paula S; Ribeiro, Jorge P; Balzan, Fernanda Machado; Mundstock, Lorena; Ferlin, Elton Luiz; Moraes, Ruy Silveira

    2011-07-01

    Patients with type 2 diabetes mellitus may present weakness of the inspiratory muscles. We tested the hypothesis that inspiratory muscle training (IMT) could improve inspiratory muscle strength, pulmonary function, functional capacity, and autonomic modulation in patients with type 2 diabetes and weakness of the inspiratory muscles. Maximal inspiratory muscle pressure (PImax) was evaluated in a sample of 148 patients with type 2 diabetes. Of these, 25 patients with PImaxinspiratory muscle endurance time, pulmonary function, peak oxygen uptake, and HR variability were evaluated before and after intervention. The prevalence of inspiratory muscle weakness was 29%. IMT significantly increased the PImax (118%) and the inspiratory muscle endurance time (495%), with no changes in pulmonary function, functional capacity, or autonomic modulation. There were no significant changes with placebo-IMT. Patients with type 2 diabetes may frequently present inspiratory muscle weakness. In these patients, IMT improves inspiratory muscle function with no consequences in functional capacity or autonomic modulation.

  10. Effect of transcutaneous electrical muscle stimulation on postoperative muscle mass and protein synthesis

    DEFF Research Database (Denmark)

    Vinge, O; Edvardsen, L; Jensen, F

    1996-01-01

    In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein ...... muscle protein synthesis and muscle mass after abdominal surgery and should be evaluated in other catabolic states with muscle wasting.......In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein...... synthesis were assessed by computed tomography and ribosome analysis of percutaneous muscle biopsies before surgery and on the sixth postoperative day. The percentage of polyribosomes in the ribosome suspension decreased significantly (P

  11. In cirrhotic patients reduced muscle strength is unrelated to muscle capacity for ATP turnover suggesting a central limitation

    DEFF Research Database (Denmark)

    Gam, Christiane Marie Bourgin; Nielsen, H B; Secher, Niels H.

    2011-01-01

      We investigated whether in patients with liver cirrhosis reduced muscle strength is related to dysfunction of muscle mitochondria.......  We investigated whether in patients with liver cirrhosis reduced muscle strength is related to dysfunction of muscle mitochondria....

  12. Relationship between neck muscles functions and hand muscles strenght in musicians

    OpenAIRE

    Vaina, Mindaugas

    2016-01-01

    Relationship Between Neck Muscles Functions and Hand Muscles Strenght in Musicians The aim of research work: to determine the relationship between musicians hand muscle strength, fatigue and neck strength, endurance and movement amplitude. Tasks of work: 1. To evaluate and compare the musicians playing with string and wind instruments neck muscle strength, endurance, range of motion, hand muscle strength and fatigue between the groups as well as commonly used standards. 2. To determine the re...

  13. How the condition of occlusal support affects the back muscle force and masticatory muscle activity?

    OpenAIRE

    石岡, 克; 河野, 正司; Ishioka, Masaru; Kohno, Shoji

    2002-01-01

    This study was conducted to determine how the condition of occlusal support affects the back muscle force and masticatory muscle activity. Two groups of subjects were enlisted: sport-trained group and normal group. While electrodes of the electromyography (EMG) were attached to the surface of the masticatory muscles, each subject's back muscle force was recorded during upper body stretching using a back muscle force-measuring device. The task was performed under four different occlusal suppor...

  14. Novel biomarkers of changes in muscle mass or muscle pathology

    DEFF Research Database (Denmark)

    Arvanitidis, Athanasios

    after radiotherapy, before and during the training period. TNNT1 levels were significantly elevated in the patient group compared to the control group, even before engaging in any form of physical activity. After engaging in physical training, the biomarker levels further increased through time......Muscle protein turnover is a dynamic equilibrium that regulates the body composition and homeostasis through various cytokines and proteases. When the balance between protein synthesis and protein degradation is altered, proper muscle function and regeneration is being hampered, affecting patient...... significantly affect several of the biomarkers levels measured in this study, most prominently CRPM and PINP, indicative of significantly altered turnover of extracellular matrix components and CRPM. C3M correlated with Interferon gene score, in PM and DM, and CRPM with MMT8 score in DM. We further developed...

  15. Bone marrow mesenchymal cells improve muscle function in a skeletal muscle re-injury model.

    Directory of Open Access Journals (Sweden)

    Bruno M Andrade

    Full Text Available Skeletal muscle injury is the most common problem in orthopedic and sports medicine, and severe injury leads to fibrosis and muscle dysfunction. Conventional treatment for successive muscle injury is currently controversial, although new therapies, like cell therapy, seem to be promise. We developed a model of successive injuries in rat to evaluate the therapeutic potential of bone marrow mesenchymal cells (BMMC injected directly into the injured muscle. Functional and histological assays were performed 14 and 28 days after the injury protocol by isometric tension recording and picrosirius/Hematoxilin & Eosin staining, respectively. We also evaluated the presence and the fate of BMMC on treated muscles; and muscle fiber regeneration. BMMC treatment increased maximal skeletal muscle contraction 14 and 28 days after muscle injury compared to non-treated group (4.5 ± 1.7 vs 2.5 ± 0.98 N/cm2, p<0.05 and 8.4 ± 2.3 vs. 5.7 ± 1.3 N/cm2, p<0.05 respectively. Furthermore, BMMC treatment increased muscle fiber cross-sectional area and the presence of mature muscle fiber 28 days after muscle injury. However, there was no difference in collagen deposition between groups. Immunoassays for cytoskeleton markers of skeletal and smooth muscle cells revealed an apparent integration of the BMMC within the muscle. These data suggest that BMMC transplantation accelerates and improves muscle function recovery in our extensive muscle re-injury model.

  16. Synchronous monitoring of muscle dynamics and muscle force for maximum isometric tetanus

    Science.gov (United States)

    Zakir Hossain, M.; Grill, Wolfgang

    2010-03-01

    Skeletal muscle is a classic example of a biological soft matter . At both macro and microscopic levels, skeletal muscle is exquisitely oriented for force generation and movement. In addition to the dynamics of contracting and relaxing muscle which can be monitored with ultrasound, variations in the muscle force are also expected to be monitored. To observe such force and sideways expansion variations synchronously for the skeletal muscle a novel detection scheme has been developed. As already introduced for the detection of sideways expansion variations of the muscle, ultrasonic transducers are mounted sideways on opposing positions of the monitored muscle. To detect variations of the muscle force, angle of pull of the monitored muscle has been restricted by the mechanical pull of the sonic force sensor. Under this condition, any variation in the time-of-flight (TOF) of the transmitted ultrasonic signals can be introduced by the variation of the path length between the transducers. The observed variations of the TOF are compared to the signals obtained by ultrasound monitoring for the muscle dynamics. The general behavior of the muscle dynamics and muscle force shows almost an identical concept. Since muscle force also relates the psychological boosting-up effects, the influence of boosting-up on muscle force and muscle dynamics can also be quantified form this study. Length-tension or force-length and force-velocity relationship can also be derived quantitatively with such monitoring.

  17. Muscle Selection for Focal Limb Dystonia.

    Science.gov (United States)

    Karp, Barbara Illowsky; Alter, Katharine

    2017-12-29

    Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia.

  18. Muscle Selection for Focal Limb Dystonia

    Directory of Open Access Journals (Sweden)

    Barbara Illowsky Karp

    2017-12-01

    Full Text Available Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia.

  19. Cytokines: muscle protein and amino acid metabolism

    DEFF Research Database (Denmark)

    van Hall, Gerrit

    2012-01-01

    raises TNF-α and IL-6 to moderate levels, has only identified IL-6 as a potent cytokine, decreasing systemic amino acid levels and muscle protein metabolism. The marked decrease in circulatory and muscle amino acid concentrations was observed with a concomitant reduction in both the rates of muscle...... of IL-6 on the regulation of muscle protein metabolism but indirectly via IL-6 reducing amino acid availability. SUMMARY: Recent studies suggest that the best described cytokines TNF-α and IL-6 are unlikely to be the major direct mediators of muscle protein loss in inflammatory diseases. However...

  20. Pathophysiology of muscle contractures in cerebral palsy.

    Science.gov (United States)

    Mathewson, Margie A; Lieber, Richard L

    2015-02-01

    Patients with cerebral palsy present with a variety of adaptations to muscle structure and function. These pathophysiologic symptoms include functional deficits such as decreased force production and range of motion, in addition to changes in muscle structure such as decreased muscle belly size, increased sarcomere length, and altered extracellular matrix structure and composition. On a cellular level, patients with cerebral palsy have fewer muscle stem cells, termed satellite cells, and altered gene expression. Understanding the nature of these changes may present opportunities for the development of new muscle treatment therapies. Published by Elsevier Inc.

  1. Human skeletal muscle releases leptin in vivo

    DEFF Research Database (Denmark)

    Wolsk, Emil; Grøndahl, Thomas Sahl; Pedersen, Bente Klarlund

    2012-01-01

    Leptin is considered an adipokine, however, cultured myocytes have also been found to release leptin. Therefore, as proof-of-concept we investigated if human skeletal muscle synthesized leptin by measuring leptin in skeletal muscle biopsies. Following this, we quantified human skeletal muscle...... was unaltered. During saline infusion the adipose tissue release averaged 0.8 ± 0.3 ng min(-1) 100g tissue(-1) whereas skeletal muscle release was 0.5 ± 0.1 ng min(-1) 100g tissue(-1). In young healthy humans, skeletal muscle contribution to whole body leptin production could be substantial given the greater...

  2. Procedural Options for Measuring Muscle Strength

    Directory of Open Access Journals (Sweden)

    Mindova S.

    2016-10-01

    Full Text Available The aim of the present study was to provide alternative means of measurement and evaluation of muscle strength in rehabilitation practice and diagnostics. In the last few years many electronic devices for evaluation of muscle strength have developed. Contemporary studies have shown that in addition to the standard manual muscle testing muscle strength can be assessed more objectively and analytically using electronic dynamometers and equipment. The strain gauges are used as a tool of precision in the industry that allows measurement of mechanical loads by dynamometers. By using these tools is possible to obtain continuous digital measurement and recording of muscle strength.

  3. AMPK in skeletal muscle function and metabolism

    DEFF Research Database (Denmark)

    Kjøbsted, Rasmus; Hingst, Janne Rasmuss; Fentz, Joachim

    2018-01-01

    highly changeable energy turnover. Due to the drastic changes in energy demand that occur between the resting and exercising state, skeletal muscle is one such tissue. Here, we review the complex regulation of AMPK in skeletal muscle and its consequences on metabolism (e.g., substrate uptake, oxidation......, and storage as well as mitochondrial function of skeletal muscle fibers). We focus on the role of AMPK in skeletal muscle during exercise and in exercise recovery. We also address adaptations to exercise training, including skeletal muscle plasticity, highlighting novel concepts and future perspectives...

  4. Muscle cramp susceptibility increases following a volitionally induced muscle cramp.

    Science.gov (United States)

    Miller, Kevin C; Long, Blaine C; Edwards, Jeffrey E

    2017-12-01

    Muscle cramping may increase peripheral nervous system excitability. It is unknown if, and how long, cramp susceptibility is affected by previous cramping. We tested whether volitionally induced muscle cramps (VIMCs) lowered cramp threshold frequency (TF c ) and how long TF c was affected post-VIMC. Fifteen cramp-prone participants volitionally induced a flexor hallucis brevis (FHB) cramp on 4 separate days. FHB TF c was measured before VIMC (i.e., baseline) and 5, 30, and 60 min post-VIMC. VIMC electromyography (EMG) amplitude, VIMC duration, and perceived VIMC intensity were measured to ensure consistency of VIMC between days. VIMC EMG amplitude, duration, and perceived intensity were similar between days (P > 0.05). VIMC lowered TF c ; baseline TF c (18 ± 6 Hz) was higher than 5-min (14 ± 6 Hz), 30-min (14 ± 5 Hz), and 60-min TF c (14 ± 5 Hz; P cramp susceptibility. Clinicians should apply treatments for at least 60 min postcramp to decrease the probability of cramp recurrence. Muscle Nerve 56: E95-E99, 2017. © 2017 Wiley Periodicals, Inc.

  5. Architectural differences between the hamstring muscles.

    Science.gov (United States)

    Kellis, Eleftherios; Galanis, Nikiforos; Kapetanos, George; Natsis, Konstantinos

    2012-08-01

    The purpose of this study was to understand the detailed architectural properties of the human hamstring muscles. The long (BFlh) and short (BFsh) head of biceps femoris, semimembranosus (SM) and semitendinosus (ST) muscles were dissected and removed from their origins in eight cadaveric specimens (age 67.8±4.3 years). Mean fiber length, sarcomere length, physiological cross-section area and pennation angle were measured. These data were then used to calculate a similarity index (δ) between pairs of muscles. The results indicated moderate similarity between BFlh and BFsh (δ=0.54) and between BFlh and SM (δ=0.35). In contrast, similarity was low between SM and ST (δ=0.98) and between BFlh and SM (δ=1.17). The fascicle length/muscle length ratio was higher for the ST (0.58) and BFsh (0.50) compared with the BFlh (0.27) and SM (0.22). There were, however, high inter-correlations between individual muscle architecture values, especially for muscle thickness and fascicle length data sets. Prediction of the whole hamstring architecture was achieved by combining data from all four muscles. These data show different designs of the hamstring muscles, especially between the SM and ST (medial) and BFlh and BFsh (lateral) muscles. Modeling the hamstrings as one muscle group by assuming uniform inter-muscular architecture yields less accurate representation of human hamstring muscle function. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Lactate and force production in skeletal muscle

    DEFF Research Database (Denmark)

    Kristensen, Michael; Albertsen, Janni; Rentsch, Maria

    2005-01-01

    Lactic acid accumulation is generally believed to be involved in muscle fatigue. However, one study reported that in rat soleus muscle (in vitro), with force depressed by high external K+ concentrations a subsequent incubation with lactic acid restores force and thereby protects against fatigue...... muscle. Three incubation solutions were used: 20 mm Na-lactate (which acidifies internal pH), 12 mm Na-lactate +8 mm lactic acid (which mimics the pH changes during muscle activity), and 20 mm lactic acid (which acidifies external pH more than internal pH). All three solutions improved force in K+-depressed...... development in repetitively stimulated muscle (Na-lactate had a negative effect). It is concluded that although lactate/lactic acid incubation regains force in K+-depressed resting muscle, a similar incubation has no or a negative effect on force development in active muscle. It is suggested...

  7. Satellite cells in human skeletal muscle plasticity.

    Science.gov (United States)

    Snijders, Tim; Nederveen, Joshua P; McKay, Bryon R; Joanisse, Sophie; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

    2015-01-01

    Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodeling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodeling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodeling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

  8. Scapular kinematic and shoulder muscle activity alterations after serratus anterior muscle fatigue.

    Science.gov (United States)

    Umehara, Jun; Kusano, Ken; Nakamura, Masatoshi; Morishita, Katsuyuki; Nishishita, Satoru; Tanaka, Hiroki; Shimizu, Itsuroh; Ichihashi, Noriaki

    2018-02-23

    Although the serratus anterior muscle has an important role in scapular movement, no study to date has investigated the effect of serratus anterior fatigue on scapular kinematics and shoulder muscle activity. The purpose of this study was to clarify the effect of serratus anterior fatigue on scapular movement and shoulder muscle activity. The study participants were 16 healthy men. Electrical muscle stimulation was used to fatigue the serratus anterior muscle. Shoulder muscle strength and endurance, scapular movement, and muscle activity were measured before and after the fatigue task. The muscle activity of the serratus anterior, upper and lower trapezius, anterior and middle deltoid, and infraspinatus muscles was recorded, and the median power frequency of these muscles was calculated to examine the degree of muscle fatigue. The muscle endurance and median power frequency of the serratus anterior muscle decreased after the fatigue tasks, whereas the muscle activities of the serratus anterior, upper trapezius, and infraspinatus muscles increased. External rotation of the scapula at the shoulder elevated position increased after the fatigue task. Selective serratus anterior fatigue due to electric muscle stimulation decreased the serratus anterior endurance at the flexed shoulder position. Furthermore, the muscle activities of the serratus anterior, upper trapezius, and infraspinatus increased and the scapular external rotation was greater after serratus anterior fatigue. These results suggest that the rotator cuff and scapular muscle compensated to avoid the increase in internal rotation of the scapula caused by the dysfunction of the serratus anterior muscle. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  9. No Muscle Is an Island

    DEFF Research Database (Denmark)

    Kent, Jane A; Ørtenblad, Niels; Hogan, Michael C

    2016-01-01

    Muscle fatigue has been studied with a variety approaches, tools and technologies. The foci of these studies have ranged tremendously, from molecules to the entire organism. Single cell and animal models have been used to gain mechanistic insight into the fatigue process. The theme of this review...... is the concept that the mechanisms of muscle fatigue do not occur in isolation in vivo: muscular work is supported by many complex physiological systems, any of which could fail during exercise and thus contribute to fatigue. To advance our overall understanding of fatigue, a combination of models and approaches...... is necessary. In this review, we examine the roles that neuromuscular properties, intracellular glycogen, oxygen metabolism, and blood flow play in the fatigue process during exercise and pathological conditions....

  10. An Artificial Muscle Ring Oscillator

    OpenAIRE

    O’Brien, Benjamin Marc; Anderson, Iain Alexander

    2012-01-01

    Dielectric elastomer artificialmuscles have great potential for the creation of novel pumps, motors, and circuitry. Control of these devices requires an oscillator, either as a driver or clock circuit, which is typically provided as part of bulky, rigid, and costly external electronics. Oscillator circuits based on piezo-resistive dielectric elastomer switch technology provide a way to embed oscillatory behavior into artificial muscle devices. Previous oscillator circuits were not digital, ab...

  11. Semimembranosus muscle herniation: a rare case with emphasis on muscle biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Naffaa, Lena [American University of Beirut, Department of Diagnostic Radiology, P.O. Box 11-0236, Riad El-Solh, Beirut (Lebanon); Moukaddam, Hicham [Saint Rita Medical Center, Lima, OH (United States); Samim, Mohammad [New York University, Department of Radiology, Hospital for Joint Disease, New York, NY (United States); Lemieux, Aaron [University of California, San Diego School of Medicine, La Jolla, CA (United States); Smitaman, Edward [University of California, San Diego, Teleradiology and Education Center, San Diego, CA (United States)

    2017-03-15

    Muscle herniations are rare and most reported cases involve muscles of the lower leg. We use a case of muscle herniation involving the semimembranosus muscle, presenting as a painful mass in an adolescent male after an unspecified American football injury, to highlight a simple concept of muscle biomechanics as it pertains to muscle hernia(s): decreased traction upon muscle fibers can increase conspicuity of muscle herniation(s) - this allows a better understanding of the apt provocative maneuvers to employ, during dynamic ultrasound or magnetic resonance imaging, in order to maximize diagnostic yield and, thereby, limit patient morbidity related to any muscle herniation. Our patient subsequently underwent successful decompressive fasciotomy and has since returned to his normal daily activities. (orig.)

  12. Semimembranosus muscle herniation: a rare case with emphasis on muscle biomechanics

    International Nuclear Information System (INIS)

    Naffaa, Lena; Moukaddam, Hicham; Samim, Mohammad; Lemieux, Aaron; Smitaman, Edward

    2017-01-01

    Muscle herniations are rare and most reported cases involve muscles of the lower leg. We use a case of muscle herniation involving the semimembranosus muscle, presenting as a painful mass in an adolescent male after an unspecified American football injury, to highlight a simple concept of muscle biomechanics as it pertains to muscle hernia(s): decreased traction upon muscle fibers can increase conspicuity of muscle herniation(s) - this allows a better understanding of the apt provocative maneuvers to employ, during dynamic ultrasound or magnetic resonance imaging, in order to maximize diagnostic yield and, thereby, limit patient morbidity related to any muscle herniation. Our patient subsequently underwent successful decompressive fasciotomy and has since returned to his normal daily activities. (orig.)

  13. Channelopathies of skeletal muscle excitability.

    Science.gov (United States)

    Cannon, Stephen C

    2015-04-01

    Familial disorders of skeletal muscle excitability were initially described early in the last century and are now known to be caused by mutations of voltage-gated ion channels. The clinical manifestations are often striking, with an inability to relax after voluntary contraction (myotonia) or transient attacks of severe weakness (periodic paralysis). An essential feature of these disorders is fluctuation of symptoms that are strongly impacted by environmental triggers such as exercise, temperature, or serum K(+) levels. These phenomena have intrigued physiologists for decades, and in the past 25 years the molecular lesions underlying these disorders have been identified and mechanistic studies are providing insights for therapeutic strategies of disease modification. These familial disorders of muscle fiber excitability are "channelopathies" caused by mutations of a chloride channel (ClC-1), sodium channel (NaV1.4), calcium channel (CaV1.1), and several potassium channels (Kir2.1, Kir2.6, and Kir3.4). This review provides a synthesis of the mechanistic connections between functional defects of mutant ion channels, their impact on muscle excitability, how these changes cause clinical phenotypes, and approaches toward therapeutics. © 2015 American Physiological Society.

  14. Postinjection Muscle Fibrosis from Lupron

    Directory of Open Access Journals (Sweden)

    Erica Everest

    2015-01-01

    Full Text Available We describe the case of a 6.5-year-old girl with central precocious puberty (CPP, which signifies the onset of secondary sexual characteristics before the age of eight in females and the age of nine in males as a result of stimulation of the hypothalamic-pituitary-gonadal axis. Her case is likely related to her adoption, as children who are adopted internationally have much higher rates of CPP. She had left breast development at Tanner Stage 2, adult body odor, and mildly advanced bone age. In order to halt puberty and maximize adult height, she was prescribed a gonadotropin releasing hormone analog, the first line treatment for CPP. She was administered Lupron (leuprolide acetate Depot-Ped (3 months intramuscularly. After her second injection, she developed swelling and muscle pain at the injection site on her right thigh. She also reported an impaired ability to walk. She was diagnosed with muscle fibrosis. This is the first reported case of muscle fibrosis resulting from Lupron injection.

  15. Optimizing calf muscle pump function.

    Science.gov (United States)

    Lattimer, Christopher R; Franceschi, Claude; Kalodiki, Evi

    2017-01-01

    Background The tip toe manoeuvre has been promoted as the gold standard plethysmography test for measuring calf muscle pump function. The aim was to compare the tip toe manoeuvre, dorsiflexion manoeuvre and a body weight transfer manoeuvre using the ejection fraction of air-plethysmography and evaluate which has the best pumping effect. Methods Sixty-six archived tracings on 22 legs were retrieved from an air-plethysmography workshop and analysed. Pumping performance was measured using the calf volume reduction after each manoeuvre. Results Expressed as median [inter-quartile range], body weight transfer manoeuvres resulted in a significantly greater ejection fraction (%) than tip toe manoeuvres at 59.7 [53.5-63.9] versus 42.6 [30.5-52.6], P calf muscle pump with a 40.1% relative increase in the ejection fraction compared to a tip toe manoeuvre. Exercises which involve body weight transfers from one leg to the other may be more important in optimizing calf muscle pump function than ankle movement exercises.

  16. Nutrition and Muscle in Cirrhosis.

    Science.gov (United States)

    Anand, Anil C

    2017-12-01

    As the cirrhosis progresses, development of complication like ascites, hepatic encephalopathy, variceal bleeding, kidney dysfunction, and hepatocellular carcinoma signify increasing risk of short term mortality. Malnutrition and muscle wasting (sarcopenia) is yet other complications that negatively impact survival, quality of life, and response to stressors, such as infection and surgery in patients with cirrhosis. Conventionally, these are not routinely looked for, because nutritional assessment can be a difficult especially if there is associated fluid retention and/or obesity. Patients with cirrhosis may have a combination of loss of skeletal muscle and gain of adipose tissue, culminating in the condition of "sarcopenic obesity." Sarcopenia in cirrhotic patients has been associated with increased mortality, sepsis complications, hyperammonemia, overt hepatic encephalopathy, and increased length of stay after liver transplantation. Assessment of muscles with cross-sectional imaging studies has become an attractive index of nutritional status evaluation in cirrhosis, as sarcopenia, the major component of malnutrition, is primarily responsible for the adverse clinical consequences seen in patients with liver disease. Cirrhosis is a state of accelerated starvation, with increased gluconeogenesis that requires amino acid diversion from other metabolic functions. Protein homeostasis is disturbed in cirrhosis due to several factors such as hyperammonemia, hormonal, and cytokine abnormalities, physical inactivity and direct effects of ethanol and its metabolites. New approaches to manage sarcopenia are being evolved. Branched chain amino acid supplementation, Myostatin inhibitors, and mitochondrial protective agents are currently in various stages of evaluation in preclinical studies to prevent and reverse sarcopenia, in cirrhosis.

  17. Muscle power during intravenous sedation

    Directory of Open Access Journals (Sweden)

    Nobuyuki Matsuura

    2017-11-01

    Full Text Available Intravenous sedation is effective to reduce fear and anxiety in dental treatment. It also has been used for behavior modification technique in dental patients with special needs. Midazolam and propofol are commonly used for intravenous sedation. Although there have been many researches on the effects of midazolam and propofol on vital function and the recovery profile, little is known about muscle power. This review discusses the effects of intravenous sedation using midazolam and propofol on both grip strength and bite force. During light propofol sedation, grip strength increases slightly and bite force increases in a dose-dependent manner. Grip strength decreases while bite force increases during light midazolam sedation, and also during light sedation using a combination of midazolam and propofol. Flumazenil did not antagonise the increase in bite force by midazolam. These results may suggest following possibilities; (1 Activation of peripheral benzodiazepine receptors located within the temporomandibular joint region and masticatory muscles may be the cause of increasing bite force. (2 Propofol limited the long-latency exteroceptive suppression (ES2 period during jaw-opening reflex. Thus, control of masticatory muscle contraction, which is thought to have a negative feedback effect on excessive bite force, may be depressed by propofol.

  18. Stress-induced Skeletal Muscle Gadd45a Expression Reprograms Myonuclei and Causes Muscle Atrophy*

    Science.gov (United States)

    Ebert, Scott M.; Dyle, Michael C.; Kunkel, Steven D.; Bullard, Steven A.; Bongers, Kale S.; Fox, Daniel K.; Dierdorff, Jason M.; Foster, Eric D.; Adams, Christopher M.

    2012-01-01

    Diverse stresses including starvation and muscle disuse cause skeletal muscle atrophy. However, the molecular mechanisms of muscle atrophy are complex and not well understood. Here, we demonstrate that growth arrest and DNA damage-inducible 45a protein (Gadd45a) is a critical mediator of muscle atrophy. We identified Gadd45a through an unbiased search for potential downstream mediators of the stress-inducible, pro-atrophy transcription factor ATF4. We show that Gadd45a is required for skeletal muscle atrophy induced by three distinct skeletal muscle stresses: fasting, muscle immobilization, and muscle denervation. Conversely, forced expression of Gadd45a in muscle or cultured myotubes induces atrophy in the absence of upstream stress. We show that muscle-specific ATF4 knock-out mice have a reduced capacity to induce Gadd45a mRNA in response to stress, and as a result, they undergo less atrophy in response to fasting or muscle immobilization. Interestingly, Gadd45a is a myonuclear protein that induces myonuclear remodeling and a comprehensive program for muscle atrophy. Gadd45a represses genes involved in anabolic signaling and energy production, and it induces pro-atrophy genes. As a result, Gadd45a reduces multiple barriers to muscle atrophy (including PGC-1α, Akt activity, and protein synthesis) and stimulates pro-atrophy mechanisms (including autophagy and caspase-mediated proteolysis). These results elucidate a critical stress-induced pathway that reprograms muscle gene expression to cause atrophy. PMID:22692209

  19. Cyclic muscle twitch contraction inhibits immobilization-induced muscle contracture and fibrosis in rats.

    Science.gov (United States)

    Yoshimura, Ayana; Sakamoto, Junya; Honda, Yuichiro; Kataoka, Hideki; Nakano, Jiro; Okita, Minoru

    2017-09-01

    We investigated the effects of cyclic muscle twitch contraction caused by neuromuscular electrical stimulation (NMES) on immobilization-induced muscle contracture and fibrosis in rats. Twenty-nine rats were divided into control, immobilization, and immobilization with muscle contraction groups. The ankle joints of the immobilization and muscle contraction rats were fixed in full plantar flexion with a plaster cast for 4 weeks. In the muscle contraction group, cyclic muscle twitch contraction of the soleus muscle was induced using a commercial device (1 Hz, 4 ± 2 mA, 60 min/day, 5 times/week) with the ankle joint immobilized. The dorsiflexion range of ankle joint motion in the muscle contraction group was significantly greater than that in the immobilization group. The expressions of fibrosis-related genes (i.e., hypoxia inducible factor-1α, transforming growth factor-β1, α-smooth muscle actin, and types I and III collagen) were significantly decreased in the muscle contraction group compared to the immobilization group. The fluorescence intensities of type I and type III collagen in the perimysium and endomysium in the muscle contraction group were significantly decreased compared to the immobilization group. These results suggest that cyclic muscle twitch contraction induced by NMES might alleviate skeletal muscle fibrosis, reducing immobilization-induced muscle contracture.

  20. Muscle size explains low passive skeletal muscle force in heart failure patients.

    Science.gov (United States)

    Panizzolo, Fausto Antonio; Maiorana, Andrew J; Naylor, Louise H; Dembo, Lawrence G; Lloyd, David G; Green, Daniel J; Rubenson, Jonas

    2016-01-01

    Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF). However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function. Therefore, the aim of this study was to investigate passive force in a single muscle for which non-invasive measures of muscle size and estimates of fiber force are possible, the soleus (SOL), both in CHF patients and age- and physical activity-matched control participants. Passive SOL muscle force and size were obtained by means of a novel approach combining experimental data (dynamometry, electromyography, ultrasound imaging) with a musculoskeletal model. We found reduced passive SOL forces (∼30%) (at the same relative levels of muscle stretch) in CHF vs. healthy individuals. This difference was eliminated when force was normalized by physiological cross sectional area, indicating that reduced force output may be most strongly associated with muscle size. Nevertheless, passive force was significantly higher in CHF at a given absolute muscle length (non length-normalized) and likely explained by the shorter muscle slack lengths and optimal muscle lengths measured in CHF compared to the control participants. This later factor may lead to altered performance of the SOL in functional tasks such gait. These findings suggest introducing exercise rehabilitation targeting muscle hypertrophy and, specifically for the calf muscles, exercise that promotes muscle lengthening.

  1. Muscle oxygenation and fascicle length during passive muscle stretching in ballet-trained subjects.

    Science.gov (United States)

    Otsuki, A; Fujita, E; Ikegawa, S; Kuno-Mizumura, M

    2011-07-01

    Muscle stretching transiently decreases muscle-blood flow corresponding to a muscle extension. It may disturb a balance between muscular oxygen demand and oxygen supply to muscles and reduce muscle oxygenation. However, muscle-stretching training may improve blood circulatory condition, resulting in the maintained muscle oxygenation during muscle stretching. The aim of this study was to investigate changes in muscle-blood volume (tHb) and tissue oxygenation index (TOI) during muscle stretching determined by using near-infrared spectroscopy (NIRS) in ballet-trained (BT) and untrained (C) subjects. 11 BT women who regularly perform muscle stretching and 11 C women participated in this study. Fascicle lengths, tHb and TOI in the tibialis anterior muscle were measured during passive plantar flexion from ankle joint angles of 120° (baseline) to 140°, 160°, the maximal comfortable position without pain (CP), and the maximal position (MP). At 160°, the % fascicle-length change from baseline was significantly lower in the BT than the C group, however, for the changes in tHb and TOI the significant interaction effect between the 2 groups was not detected. On the other hand, although the increases in the fascicle length from baseline to CP and MP were greater in BT than C, the tHb and TOI reductions were comparable between groups. We concluded that it appears that BT can extend their muscles without excessive reduction in muscle-blood volume and muscle oxygenation at relatively same but absolutely greater muscle-stretching levels than C. The attenuation in these indices during high-level muscle stretching may be associated with the repetitive muscle stretching of long-term ballet training. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Extraocular muscle architecture in hawks and owls.

    Science.gov (United States)

    Plochocki, Jeffrey H; Segev, Tamar; Grow, Wade; Hall, Margaret I

    2018-02-06

    A complete and accurate understanding of extraocular muscle function is important to the veterinary care of the avian eye. This is especially true for birds of prey, which rely heavily on vision for survival and yet are prone to ocular injury and disease. To better understand the function of extraocular muscles in birds of prey, we studied extraocular muscle architecture grossly and histologically. This sample was composed of two each of the following species: red-tailed hawk (Buteo jamaicensis), Harris's hawk (Parabuteo unicinctus), great horned owl (Bubo virginianus), and barn owl (Tyto alba). All extraocular muscles were dissected and weighed. To analyze muscle fiber architecture, the superior oblique and quadratus muscles were dissected, weighed, and sectioned at 5 μm thickness in the transverse plane. We calculated the physiologic cross-sectional area and the ratio of muscle mass to predicted effective maximum tetanic tension. Hawk and owl extraocular muscles exhibit significant physiological differences that play roles in ocular movements and closure of the nictitating membrane. Owls, which do not exhibit extraocular movement, have muscle architecture suited to stabilize the position of a massive, tubular eye that protrudes significantly from the orbit. Hawks, which have a more globose eye that is largely contained within the orbit, do not require as much muscular stability and instead have muscle architecture that facilitates rapid eye movement. © 2018 American College of Veterinary Ophthalmologists.

  3. Space travel directly induces skeletal muscle atrophy

    Science.gov (United States)

    Vandenburgh, H.; Chromiak, J.; Shansky, J.; Del Tatto, M.; Lemaire, J.

    1999-01-01

    Space travel causes rapid and pronounced skeletal muscle wasting in humans that reduces their long-term flight capabilities. To develop effective countermeasures, the basis of this atrophy needs to be better understood. Space travel may cause muscle atrophy indirectly by altering circulating levels of factors such as growth hormone, glucocorticoids, and anabolic steroids and/or by a direct effect on the muscle fibers themselves. To determine whether skeletal muscle cells are directly affected by space travel, tissue-cultured avian skeletal muscle cells were tissue engineered into bioartificial muscles and flown in perfusion bioreactors for 9 to 10 days aboard the Space Transportation System (STS, i.e., Space Shuttle). Significant muscle fiber atrophy occurred due to a decrease in protein synthesis rates without alterations in protein degradation. Return of the muscle cells to Earth stimulated protein synthesis rates of both muscle-specific and extracellular matrix proteins relative to ground controls. These results show for the first time that skeletal muscle fibers are directly responsive to space travel and should be a target for countermeasure development.

  4. The regulation of catch in molluscan muscle.

    Science.gov (United States)

    Twarog, B M

    1967-07-01

    Molluscan catch muscles are smooth muscles. As with mammalian smooth muscles, there is no transverse ordering of filaments or dense bodies. In contrast to mammalian smooth muscles, two size ranges of filaments are present. The thick filaments are long as well as large in diameter and contain paramyosin. The thin filaments contain actin and appear to run into and join the dense bodies. Vesicles are present which may be part of a sarcoplasmic reticulum. Neural activation of contraction in Mytilus muscle is similar to that observed in mammalian smooth muscles, and in some respects to frog striated muscle. The relaxing nerves, which reduce catch, are unique to catch muscles. 5-Hydroxytryptamine, which appears to mediate relaxation, specifically blocks catch tension but increases the ability of the muscle to fire spikes. It is speculated that Mytilus muscle actomyosin is activated by a Ca(++)-releasing mechanism, and that 5-hydroxytryptamine may reduce catch and increase excitability by influencing the rate of removal of intracellular free Ca(++).

  5. Muscle activity characterization by laser Doppler Myography

    International Nuclear Information System (INIS)

    Scalise, Lorenzo; Casaccia, Sara; Marchionni, Paolo; Ercoli, Ilaria; Tomasini, Enrico Primo

    2013-01-01

    Electromiography (EMG) is the gold-standard technique used for the evaluation of muscle activity. This technique is used in biomechanics, sport medicine, neurology and rehabilitation therapy and it provides the electrical activity produced by skeletal muscles. Among the parameters measured with EMG, two very important quantities are: signal amplitude and duration of muscle contraction, muscle fatigue and maximum muscle power. Recently, a new measurement procedure, named Laser Doppler Myography (LDMi), for the non contact assessment of muscle activity has been proposed to measure the vibro-mechanical behaviour of the muscle. The aim of this study is to present the LDMi technique and to evaluate its capacity to measure some characteristic features proper of the muscle. In this paper LDMi is compared with standard superficial EMG (sEMG) requiring the application of sensors on the skin of each patient. sEMG and LDMi signals have been simultaneously acquired and processed to test correlations. Three parameters has been analyzed to compare these techniques: Muscle activation timing, signal amplitude and muscle fatigue. LDMi appears to be a reliable and promising measurement technique allowing the measurements without contact with the patient skin

  6. Muscle activity characterization by laser Doppler Myography

    Science.gov (United States)

    Scalise, Lorenzo; Casaccia, Sara; Marchionni, Paolo; Ercoli, Ilaria; Primo Tomasini, Enrico

    2013-09-01

    Electromiography (EMG) is the gold-standard technique used for the evaluation of muscle activity. This technique is used in biomechanics, sport medicine, neurology and rehabilitation therapy and it provides the electrical activity produced by skeletal muscles. Among the parameters measured with EMG, two very important quantities are: signal amplitude and duration of muscle contraction, muscle fatigue and maximum muscle power. Recently, a new measurement procedure, named Laser Doppler Myography (LDMi), for the non contact assessment of muscle activity has been proposed to measure the vibro-mechanical behaviour of the muscle. The aim of this study is to present the LDMi technique and to evaluate its capacity to measure some characteristic features proper of the muscle. In this paper LDMi is compared with standard superficial EMG (sEMG) requiring the application of sensors on the skin of each patient. sEMG and LDMi signals have been simultaneously acquired and processed to test correlations. Three parameters has been analyzed to compare these techniques: Muscle activation timing, signal amplitude and muscle fatigue. LDMi appears to be a reliable and promising measurement technique allowing the measurements without contact with the patient skin.

  7. Synchronous monitoring of muscle dynamics and electromyogram

    Science.gov (United States)

    Zakir Hossain, M.; Grill, Wolfgang

    2011-04-01

    A non-intrusive novel detection scheme has been implemented to detect the lateral muscle extension, force of the skeletal muscle and the motor action potential (EMG) synchronously. This allows the comparison of muscle dynamics and EMG signals as a basis for modeling and further studies to determine which architectural parameters are most sensitive to changes in muscle activity. For this purpose the transmission time for ultrasonic chirp signal in the frequency range of 100 kHz to 2.5 MHz passing through the muscle under observation and respective motor action potentials are recorded synchronously to monitor and quantify biomechanical parameters related to muscle performance. Additionally an ultrasonic force sensor has been employed for monitoring. Ultrasonic traducers are placed on the skin to monitor muscle expansion. Surface electrodes are placed suitably to pick up the potential for activation of the monitored muscle. Isometric contraction of the monitored muscle is ensured by restricting the joint motion with the ultrasonic force sensor. Synchronous monitoring was initiated by a software activated audio beep starting at zero time of the subsequent data acquisition interval. Computer controlled electronics are used to generate and detect the ultrasonic signals and monitor the EMG signals. Custom developed software and data analysis is employed to analyze and quantify the monitored data. Reaction time, nerve conduction speed, latent period between the on-set of EMG signals and muscle response, degree of muscle activation and muscle fatigue development, rate of energy expenditure and motor neuron recruitment rate in isometric contraction, and other relevant parameters relating to muscle performance have been quantified with high spatial and temporal resolution.

  8. An anatomic and biomechanic study of the wrist extensor retinaculum septa and tendon compartments.

    Science.gov (United States)

    Iwamoto, Akira; Morris, Randal P; Andersen, Clark; Patterson, Rita M; Viegas, Steven F

    2006-01-01

    The anatomy of the extensor retinaculum of the wrist has been described previously; the purpose of this study was to describe the specific anatomy of the septal attachments on the radius and to investigate the mechanical strength of each septal attachment on the radius and each of the 6 compartments of the extensor retinaculum. Thirty-four wrists from 24 fresh-frozen and 10 embalmed cadavers were used. First, anatomic measurements of the individual extensor retinaculum septums were performed with calipers and a 3-dimensional digitizer. Next each extensor retinaculum septum was excised as a bone-retinaculum-bone autograft and was tested in tension to failure with a materials testing machine. Finally the 6 extensor retinaculum compartments were tested to failure. Septum 1/2 had the largest radial surface area and septum 3/4 had the smallest. Septum 1/2 also was found to have the highest failure strength at 51.3 +/- 15.3 N. In compartment testing, compartments 1 and 2 had the highest overall resistance to failure and compartment 5 had the lowest. Compartment 6, which was thought to be the weakest because of clinically observed subluxation of the extensor carpi ulnaris tendon, had stronger failure data than expected. This study offers detailed analysis of the extensor retinaculum compartments and 3-dimensional anatomy of the septal attachments. Clinically this study lends insight to the strength of bone-retinaculum-bone autografts and the etiology of extensor carpi ulnaris subluxation.

  9. Individual muscle control using an exoskeleton robot for muscle function testing.

    Science.gov (United States)

    Ueda, Jun; Ming, Ding; Krishnamoorthy, Vijaya; Shinohara, Minoru; Ogasawara, Tsukasa

    2010-08-01

    Healthy individuals modulate muscle activation patterns according to their intended movement and external environment. Persons with neurological disorders (e.g., stroke and spinal cord injury), however, have problems in movement control due primarily to their inability to modulate their muscle activation pattern in an appropriate manner. A functionality test at the level of individual muscles that investigates the activity of a muscle of interest on various motor tasks may enable muscle-level force grading. To date there is no extant work that focuses on the application of exoskeleton robots to induce specific muscle activation in a systematic manner. This paper proposes a new method, named "individual muscle-force control" using a wearable robot (an exoskeleton robot, or a power-assisting device) to obtain a wider variety of muscle activity data than standard motor tasks, e.g., pushing a handle by hand. A computational algorithm systematically computes control commands to a wearable robot so that a desired muscle activation pattern for target muscle forces is induced. It also computes an adequate amount and direction of a force that a subject needs to exert against a handle by his/her hand. This individual muscle control method enables users (e.g., therapists) to efficiently conduct neuromuscular function tests on target muscles by arbitrarily inducing muscle activation patterns. This paper presents a basic concept, mathematical formulation, and solution of the individual muscle-force control and its implementation to a muscle control system with an exoskeleton-type robot for upper extremity. Simulation and experimental results in healthy individuals justify the use of an exoskeleton robot for future muscle function testing in terms of the variety of muscle activity data.

  10. Measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography.

    Science.gov (United States)

    Chino, Kentaro; Akagi, Ryota; Dohi, Michiko; Takahashi, Hideyuki

    2014-09-01

    The B-mode ultrasound image that can measure muscle architecture is displayed side by side with the ultrasound strain elastogram that can assess muscle hardness. Consequently, muscle architecture can be measured concurrently with muscle hardness using ultrasound strain elastography. To demonstrate the measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography. Concurrent measurements of muscle architectural parameters (muscle thickness, pennation angle, and fascicle length) and muscle hardness of the medial gastrocnemius were performed with ultrasound strain elastography. Separate measurements of the muscle architectural parameters were also performed for use as reference values for the concurrent measurements. Both types of measurements were performed twice at 20° dorsiflexion, neutral position, and 30° plantar flexion. Coefficients of variance of the muscle architectural parameters obtained from the concurrent measurements (≤7.6%) were significantly higher than those obtained from the separate measurements (≤2.4%) (all P  0.05). The use of ultrasound strain elastography for the concurrent measurement of muscle architecture and muscle hardness is feasible. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  11. An analysis on muscle tone of lower limb muscles on flexible flat foot.

    Science.gov (United States)

    Um, Gi-Mai; Wang, Joong-San; Park, Si-Eun

    2015-10-01

    [Purpose] The aim of this study was to examine differences in the muscle tone and stiffness of leg muscles according to types of flexible flat foot. [Subjects and Methods] For 30 subjects 10 in a normal foot group (NFG), 10 in group with both flexible flat feet (BFFG), and 10 in a group with flexible flat feet on one side (OFFG), myotonometry was used to measure the muscle tone and stiffness of the tibialis anterior muscle (TA), the rectus femoris muscle (RF), the medial gastrocnemius (MG), and the long head of the biceps femoris muscle (BF) of both lower extremities. [Results] In the measurement results, only the stiffness of TA and MG of the NFG and the BFFG showed significant differences. The muscle tone and stiffness were highest in the BFFG, followed by the OFFG and NFG, although the difference was insignificant. In the case of the OFFG, there was no significant difference in muscle tone and stiffness compared to that in the NGF and the BFFG. Furthermore, in the NFG, the non-dominant leg showed greater muscle tone and stiffness than the dominant leg, although the difference was insignificant. [Conclusion] During the relax condition, the flexible flat foot generally showed a greater muscle tone and stiffness of both lower extremities compared to the normal foot. The stiffness was particularly higher in the TA and MG muscles. Therefore, the muscle tone and stiffness of the lower extremity muscles must be considered in the treatment of flat foot.

  12. Can Measured Synergy Excitations Accurately Construct Unmeasured Muscle Excitations?

    Science.gov (United States)

    Bianco, Nicholas A; Patten, Carolynn; Fregly, Benjamin J

    2018-01-01

    Accurate prediction of muscle and joint contact forces during human movement could improve treatment planning for disorders such as osteoarthritis, stroke, Parkinson's disease, and cerebral palsy. Recent studies suggest that muscle synergies, a low-dimensional representation of a large set of muscle electromyographic (EMG) signals (henceforth called "muscle excitations"), may reduce the redundancy of muscle excitation solutions predicted by optimization methods. This study explores the feasibility of using muscle synergy information extracted from eight muscle EMG signals (henceforth called "included" muscle excitations) to accurately construct muscle excitations from up to 16 additional EMG signals (henceforth called "excluded" muscle excitations). Using treadmill walking data collected at multiple speeds from two subjects (one healthy, one poststroke), we performed muscle synergy analysis on all possible subsets of eight included muscle excitations and evaluated how well the calculated time-varying synergy excitations could construct the remaining excluded muscle excitations (henceforth called "synergy extrapolation"). We found that some, but not all, eight-muscle subsets yielded synergy excitations that achieved >90% extrapolation variance accounted for (VAF). Using the top 10% of subsets, we developed muscle selection heuristics to identify included muscle combinations whose synergy excitations achieved high extrapolation accuracy. For 3, 4, and 5 synergies, these heuristics yielded extrapolation VAF values approximately 5% lower than corresponding reconstruction VAF values for each associated eight-muscle subset. These results suggest that synergy excitations obtained from experimentally measured muscle excitations can accurately construct unmeasured muscle excitations, which could help limit muscle excitations predicted by muscle force optimizations.

  13. [Inspiratory muscles strength training in recreational athletes].

    Science.gov (United States)

    Kellens, I; Cannizzaro, F; Gouilly, P; Crielaard, J-M

    2011-05-01

    Respiratory muscles strength and endurance influence athletic performance. Besides conventional spirometry, sniff test, inspiratory and expiratory maximal pressures can directly assess respiratory muscle strength. Respiratory muscles can be train through a device offering inspiratory and expiratory resistance. Nineteen subjects aged 18 to 30 years and practicing leisure sport trained inspiratory muscles on Powerbreathe(®) for eight weeks. Resistance was set at 85% of maximal inspiratory pressure determined during a preliminary session. Evaluation was made trough voluntary and non-invasive methods on Macro 5000(®) (PI max, PE max and sniff test). An increase of 21.77% of the maximum inspiratory pressure, 17% of the maximum expiratory pressure and 18% of the sniff test are recorded after eight weeks of training. A specific training of inspiratory muscles (Powerbreathe(®) Sports performance) increases the power of these muscles (voluntary and non-invasive tests). Copyright © 2011 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  14. Mechanisms of exertional fatigue in muscle glycogenoses

    DEFF Research Database (Denmark)

    Vissing, John; Haller, Ronald G

    2012-01-01

    Exertional fatigue early in exercise is a clinical hallmark of muscle glycogenoses, which is often coupled with painful muscle contractures and episodes of myoglobinuria. A fundamental biochemical problem in these conditions is the impaired generation of ATP to fuel muscle contractions, which...... relates directly to the metabolic defect, but also to substrate-limited energy deficiency, as exemplified by the "second wind" phenomenon in McArdle disease. A number of secondary events may also play a role in inducing premature fatigue in glycogenoses, including (1) absent or blunted muscle acidosis......, which may be important for maintaining muscle membrane excitability by decreasing chloride permeability, (2) loss of the osmotic effect related to lactate accumulation, which may account for absence of the normal increase in water content of exercised muscle, and thus promote higher than normal...

  15. [Molecular mechanisms of skeletal muscle hypertrophy].

    Science.gov (United States)

    Astratenkova, I V; Rogozkin, V A

    2014-06-01

    Enzymes Akt, AMPK, mTOR, S6K and PGC-1a coactivator take part in skeletal muscles in the regulation of synthesis of proteins. The expression of these proteins is regulated by growth factors, hormones, nutrients, mechanical loading and leads to an increase in muscle mass and skeletal muscle hypertrophy. The review presents the results of studies published in the past four years, which expand knowledge on the effects of various factors on protein synthesis in skeletal muscle. The attention is focused on the achievements that reveal and clarify the signaling pathways involved in the regulation of protein synthesis in skeletal muscle. The central place is taken by mTOR enzyme which controls and regulates the main stages of the cascade of reactions of muscle proteins providing synthesis in the conditions of human life. coactivator PGC-1a.

  16. Signaling pathways controlling skeletal muscle mass

    Science.gov (United States)

    Egerman, Marc A.

    2014-01-01

    The molecular mechanisms underlying skeletal muscle maintenance involve interplay between multiple signaling pathways. Under normal physiological conditions, a network of interconnected signals serves to control and coordinate hypertrophic and atrophic messages, culminating in a delicate balance between muscle protein synthesis and proteolysis. Loss of skeletal muscle mass, termed “atrophy”, is a diagnostic feature of cachexia seen in settings of cancer, heart disease, chronic obstructive pulmonary disease, kidney disease, and burns. Cachexia increases the likelihood of death from these already serious diseases. Recent studies have further defined the pathways leading to gain and loss of skeletal muscle as well as the signaling events that induce differentiation and post-injury regeneration, which are also essential for the maintenance of skeletal muscle mass. In this review, we summarize and discuss the relevant recent literature demonstrating these previously undiscovered mediators governing anabolism and catabolism of skeletal muscle. PMID:24237131

  17. Radioisotope scanning in inflammatory muscle disease

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.B.; Swift, T.R.; Spies, S.M.

    1976-06-01

    Fourteen whole-body rectilinear bone scans using technetium 99m-polyphosphate were done in nine patients with well-documented inflammatory myopathy (either polymyositis or dermatomyositis). In all nine patients the scans showed evidence of increased muscle labeling. Muscle uptake was markedly increased in one patient, moderately increased in two patients, and minimally increased in six patients. The degree of muscle labeling correlated with the severity of the muscle weakness at the time the scan was done. In four patients, who received high-dose corticosteroid treatment, muscle uptake was decreased following therapy. These findings suggest that radioisotope scanning may be useful in the diagnosis and management of patients with inflammatory muscle diseases.

  18. Experimental knee pain reduces muscle strength

    DEFF Research Database (Denmark)

    Henriksen, Marius; Mortensen, Sara Rosager; Aaboe, Jens

    2011-01-01

    Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

  19. Modelling of pneumatic muscle actuator using Hill's model with different approximations of static characteristics of artificial muscle

    OpenAIRE

    Piteľ Ján; Tóthová Mária

    2016-01-01

    For modelling and simulation of pneumatic muscle actuators the mathematical dependence of the muscle force on the muscle contraction at different pressures in the muscles is necessary to know. For this purpose the static characteristics of the pneumatic artificial muscle type FESTO MAS-20-250N used in the experiments were approximated. In the paper there are shown some simulation results of the pneumatic muscle actuator dynamics using modified Hill's muscle model, in which four different appr...

  20. Traumatic avulsion of extraocular muscles: case reports

    Directory of Open Access Journals (Sweden)

    Nilza Minguini

    2013-04-01

    Full Text Available We described the clinical, surgical details and results (motor and sensory of the retrieving procedure of traumatically avulsed muscles in three patients with no previous history of strabismus or diplopia seen in the Department of Ophthalmology, State University of Campinas, Brazil. The slipped muscle portion was reinserted at the original insertion and under the remaining stump, which was sutured over the reinserted muscle. For all three cases there was recovery of single binocular vision and stereopsis.

  1. Familial muscle cramps with autosomal dominant transmission.

    Science.gov (United States)

    Van den Bergh, P; Bulcke, J A; Dom, R

    1980-01-01

    A family is described with generalized muscle cramps inherited as an autosomal dominant trait and with maximal expression during adolescence. The age of onset varies between 10 and 15 years. Muscle enzymes are elevated with a peak level between 15 and 25 years. The complaints seem to disappear after the age of 25 years. EMG and muscle biopsies suggest a neurogenic origin of the cramps.

  2. Muscle Synergy-Driven Robust Motion Control.

    Science.gov (United States)

    Min, Kyuengbo; Iwamoto, Masami; Kakei, Shinji; Kimpara, Hideyuki

    2018-04-01

    Humans are able to robustly maintain desired motion and posture under dynamically changing circumstances, including novel conditions. To accomplish this, the brain needs to optimize the synergistic control between muscles against external dynamic factors. However, previous related studies have usually simplified the control of multiple muscles using two opposing muscles, which are minimum actuators to simulate linear feedback control. As a result, they have been unable to analyze how muscle synergy contributes to motion control robustness in a biological system. To address this issue, we considered a new muscle synergy concept used to optimize the synergy between muscle units against external dynamic conditions, including novel conditions. We propose that two main muscle control policies synergistically control muscle units to maintain the desired motion against external dynamic conditions. Our assumption is based on biological evidence regarding the control of multiple muscles via the corticospinal tract. One of the policies is the group control policy (GCP), which is used to control muscle group units classified based on functional similarities in joint control. This policy is used to effectively resist external dynamic circumstances, such as disturbances. The individual control policy (ICP) assists the GCP in precisely controlling motion by controlling individual muscle units. To validate this hypothesis, we simulated the reinforcement of the synergistic actions of the two control policies during the reinforcement learning of feedback motion control. Using this learning paradigm, the two control policies were synergistically combined to result in robust feedback control under novel transient and sustained disturbances that did not involve learning. Further, by comparing our data to experimental data generated by human subjects under the same conditions as those of the simulation, we showed that the proposed synergy concept may be used to analyze muscle synergy

  3. [Autocontrol of muscle relaxation with vecuronium].

    Science.gov (United States)

    Sibilla, C; Zatelli, R; Marchi, M; Zago, M

    1990-01-01

    The optimal conditions for maintaining desired levels of muscle relaxation with vecuronium are obtained by means of the continuous infusion (I.V.) technique. A frequent correction of the infusion flow is required, since it is impossible to predict the exact amount for the muscle relaxant in single case. In order to overcome such limits the authors propose a very feasible infusion system for the self-control of muscle relaxation; furthermore they positively consider its possible daily clinical application.

  4. 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

  5. Insulin binding to individual rat skeletal muscles

    Energy Technology Data Exchange (ETDEWEB)

    Koerker, D.J.; Sweet, I.R.; Baskin, D.G. (Univ. of Washington, Seattle (USA))

    1990-10-01

    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.

  6. Heat stress inhibits skeletal muscle hypertrophy

    OpenAIRE

    Frier, Bruce C.; Locke, Marius

    2007-01-01

    Heat shock proteins (Hsps) are molecular chaperones that aid in protein synthesis and trafficking and have been shown to protect cells/tissues from various protein damaging stressors. To determine the extent to which a single heat stress and the concurrent accumulation of Hsps influences the early events of skeletal muscle hypertrophy, Sprague-Dawley rats were heat stressed (42°C, 15 minutes) 24 hours prior to overloading 1 plantaris muscle by surgical removal of the gastrocnemius muscle. The...

  7. Targeted Muscle Reinnervation and Advanced Prosthetic Arms

    OpenAIRE

    Cheesborough, Jennifer E.; Smith, Lauren H.; Kuiken, Todd A.; Dumanian, Gregory A.

    2015-01-01

    Targeted muscle reinnervation (TMR) is a surgical procedure used to improve the control of upper limb prostheses. Residual nerves from the amputated limb are transferred to reinnervate new muscle targets that have otherwise lost their function. These reinnervated muscles then serve as biological amplifiers of the amputated nerve motor signals, allowing for more intuitive control of advanced prosthetic arms. Here the authors provide a review of surgical techniques for TMR in patients with eith...

  8. Role of Smooth Muscle in Intestinal Inflammation

    Directory of Open Access Journals (Sweden)

    Stephen M Collins

    1996-01-01

    Full Text Available The notion that smooth muscle function is altered in inflammation is prompted by clinical observations of altered motility in patients with inflammatory bowel disease (IBD. While altered motility may reflect inflammation-induced changes in intrinsic or extrinsic nerves to the gut, changes in gut hormone release and changes in muscle function, recent studies have provided in vitro evidence of altered muscle contractility in muscle resected from patients with ulcerative colitis or Crohn’s disease. In addition, the observation that smooth muscle cells are more numerous and prominent in the strictured bowel of IBD patients compared with controls suggests that inflammation may alter the growth of intestinal smooth muscle. Thus, inflammation is associated with changes in smooth muscle growth and contractility that, in turn, contribute to important symptoms of IBD including diarrhea (from altered motility and pain (via either altered motility or stricture formation. The involvement of smooth muscle in this context may be as an innocent bystander, where cells and products of the inflammatory process induce alterations in muscle contractility and growth. However, it is likely that intestinal muscle cells play a more active role in the inflammatory process via the elaboration of mediators and trophic factors, including cytokines, and via the production of collagen. The concept of muscle cells as active participants in the intestinal inflammatory process is a new concept that is under intense study. This report summarizes current knowledge as it relates to these two aspects of altered muscle function (growth and contractility in the inflamed intestine, and will focus on mechanisms underlying these changes, based on data obtained from animal models of intestinal inflammation.

  9. Muscle changes in aging: understanding sarcopenia.

    Science.gov (United States)

    Siparsky, Patrick N; Kirkendall, Donald T; Garrett, William E

    2014-01-01

    Muscle physiology in the aging athlete is complex. Sarcopenia, the age-related decrease in lean muscle mass, can alter activity level and affect quality of life. This review addresses the microscopic and macroscopic changes in muscle with age, recognizes contributing factors including nutrition and changes in hormone levels, and identifies potential pharmacologic agents in clinical trial that may aid in the battle of this complex, costly, and disabling problem. Level 5.

  10. Magnesium for skeletal muscle cramps.

    Science.gov (United States)

    Garrison, Scott R; Allan, G Michael; Sekhon, Ravneet K; Musini, Vijaya M; Khan, Karim M

    2012-09-12

    Skeletal muscle cramps are common and often presented to physicians in association with pregnancy, advanced age, exercise or disorders of the motor neuron (such as amyotrophic lateral sclerosis). Magnesium supplements are marketed for the prophylaxis of cramps but the efficacy of magnesium for this indication has never been evaluated by systematic review. To assess the effects of magnesium supplementation compared to no treatment, placebo control or other cramp therapies in people with skeletal muscle cramps.   We searched the Cochrane Neuromuscular Disease Group Specialized Register (11 October 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 3), MEDLINE (January 1966 to September 2011), EMBASE (January 1980 to September 2011), LILACS (January 1982 to September 2011), CINAHL Plus (January 1937 to September 2011), AMED (January 1985 to October 2011) and SPORTDiscus (January 1975 to September 2011). Randomized controlled trials (RCTs) of magnesium supplementation (in any form) to prevent skeletal muscle cramps in any patient group (i.e. all clinical presentations of cramp). We considered comparisons of magnesium with no treatment, placebo control, or other therapy. Two authors independently selected trials for inclusion and extracted data. Two authors assessed risk of bias. We attempted to contact all study authors and obtained patient level data for three of the included trials, one of which was unpublished. All data on adverse effects were collected from the included RCTs. We identified seven trials (five parallel, two cross-over) enrolling a total of 406 individuals amongst whom 118 cross-over participants additionally served as their own controls. Three trials enrolled women with pregnancy-associated leg cramps (N = 202) and four trials enrolled idiopathic cramp sufferers (N = 322 including cross-over controls). Magnesium was compared to placebo in six trials and to no treatment in one trial.For idiopathic cramps (largely older

  11. A variation of the extensor hallucis longus muscle (accessory extensor digiti secundus muscle).

    Science.gov (United States)

    Tezer, Murat; Cicekcibasi, Aynur Emine

    2012-06-01

    An accessory muscle adjacent to the extensor hallucis longus muscle (EHL) was observed between the EHL and the extensor digitorum longus muscle (EDL) in the anterior side of both legs of the cadaver of a 72-year-old male, during educational dissection, and it was observed that the tendon of this muscle extended to the second toe. The tendon of this muscle united with the second toe tendon of the EDL. These common tendons appeared before reaching the toe media phalanxes and extended to the related media phalanxes of toe. However, an additional tendon separating from this accessory muscle tendon united with the EHL tendon at the left foot. This accessory muscle, unlike the variations identified to date, is considered to extend to the second toe, and the name "accessory extensor digiti secundus muscle" is offered.

  12. Impaired muscle glycogen resynthesis after a marathon is not caused by decreased muscle GLUT-4 content

    DEFF Research Database (Denmark)

    Asp, S; Rohde, T; Richter, Erik

    1997-01-01

    the marathon and decreased to 148 +/- 39 mmol/kg dry weight immediately afterward. Despite a carbohydrate-rich diet (containing at least 7 g carbohydrate.kg body mass-1.day-1), the muscle glycogen concentration remained 30% lower than before-race values 2 days after the race, whereas it had returned to before......Our purpose was to investigate whether the slow rate of muscle glycogen resynthesis after a competitive marathon is associated with a decrease in the total muscle content of the muscle glucose transporter (GLUT-4). Seven well-trained marathon runners participated in the study, and muscle biopsies...... were obtained from the lateral head of the gastrocnemius muscle before, immediately after, and 1, 2, and 7 days after the marathon, as were venous blood samples. Muscle GLUT-4 content was unaltered over the experimental period. Muscle glycogen concentration was 758 +/- 53 mmol/kg dry weight before...

  13. Impaired muscle glycogen resynthesis after a marathon is not caused by decreased muscle GLUT-4 content

    DEFF Research Database (Denmark)

    Asp, S; Rohde, T; Richter, Erik

    1997-01-01

    Our purpose was to investigate whether the slow rate of muscle glycogen resynthesis after a competitive marathon is associated with a decrease in the total muscle content of the muscle glucose transporter (GLUT-4). Seven well-trained marathon runners participated in the study, and muscle biopsies...... were obtained from the lateral head of the gastrocnemius muscle before, immediately after, and 1, 2, and 7 days after the marathon, as were venous blood samples. Muscle GLUT-4 content was unaltered over the experimental period. Muscle glycogen concentration was 758 +/- 53 mmol/kg dry weight before......-race levels 7 days after the race. We conclude that the total GLUT-4 protein content is unaltered in the lateral gastrocnemius after a competitive marathon and that the slow recovery of muscle glycogen after the race apparently involves factors other than changes in the total content of this protein....

  14. Core muscle activity during suspension exercises.

    Science.gov (United States)

    Mok, Nicola W; Yeung, Ella W; Cho, Jeran C; Hui, Samson C; Liu, Kimee C; Pang, Coleman H

    2015-03-01

    Suspension exercise has been advocated as an effective means to improve core stability among healthy individuals and those with musculoskeletal complaints. However, the activity of core muscles during suspension exercises has not been reported. In this study, we investigated the level of activation of core muscles during suspension exercises within young and healthy adults. The study was conducted in a controlled laboratory setting. Surface electromyographic (sEMG) activity of core muscles (rectus abdominis, external oblique, internal oblique/transversus abdominis, and superficial lumbar multifidus) during four suspension workouts (hip abduction in plank, hamstring curl, chest press, and 45° row) was investigated. Muscle activity during a 5-s hold period of the workouts was measured by sEMG and normalized to the individual's maximal voluntary isometric contraction (MVIC). Different levels of muscle activation were observed during the hip abduction in plank, hamstring curl, and chest press. Hip abduction in plank generated the highest activation of most abdominal muscles. The 45° row exercise generated the lowest muscle activation. Among the four workouts investigated, the hip abduction in plank with suspension was found to have the strongest potential strengthening effect on core muscles. Also, suspension training was found to generate relatively high levels of core muscle activation when compared with that among previous studies of core exercises on stable and unstable support surfaces. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  15. Novel Ultrasound Assessment of Dynamic Muscle

    Data.gov (United States)

    National Aeronautics and Space Administration — Substantial research shows that skeletal muscle undergoes atrophy during spaceflight. Because maintenance of the musculoskeletal system is of crucial importance for...

  16. [Asymmetric hypertrophy of the masticatory muscles].

    Science.gov (United States)

    Arzul, L; Corre, P; Khonsari, R H; Mercier, J-M; Piot, B

    2012-06-01

    Hypertrophy of the masticatory muscles most commonly affects the masseter. Less common cases of isolated or associated temporalis hypertrophy are also reported. Parafunctional habits, and more precisely bruxism, can favor the onset of the hypertrophy. This condition is generally idiopathic and can require both medical and/or surgical management. A 29-year-old patient was referred to our department for an asymmetric swelling of the masticatory muscles. Physical examination revealed a bilateral hypertrophy of the masticatory muscles, predominantly affecting the right temporalis and the left masseter. Major bruxism was assessed by premature dental wearing. The additional examinations confirmed the isolated muscle hypertrophy. Benign asymmetric hypertrophy of the masticatory muscles promoted by bruxism was diagnosed. Treatment with injections of type A botulinum toxin was conducted in association with a splint and relaxation. Its effectiveness has been observed at six months. Few cases of unilateral or bilateral temporalis hypertrophy have been reported, added to the more common isolated masseter muscles hypertrophy. The diagnosis requires to rule out secondary hypertrophies and tumors using Magnetic Resonance Imaging. The condition is thought to be favoured by parafunctional habits such as bruxism. The conservative treatment consists in reducing the volume of the masticatory muscles using intramuscular injections of type A botulinum toxin. Other potential conservative treatments are wearing splints and muscle relaxant drugs. Surgical procedures aiming to reduce the muscle volume and/or the bone volume (mandibular gonioplasty) can be proposed. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Engineered Muscle Actuators: Cells and Tissues

    National Research Council Canada - National Science Library

    Dennis, Robert G; Herr, Hugh; Parker, Kevin K; Larkin, Lisa; Arruda, Ellen; Baar, Keith

    2007-01-01

    .... Our primary objectives were to engineer living skeletal muscle actuators in culture using integrated bioreactors to guide tissue development and to maintain tissue contractility, to achieve 50...

  18. Sex hormones and skeletal muscle weakness

    DEFF Research Database (Denmark)

    Sipilä, Sarianna; Narici, Marco; Kjaer, Michael

    2013-01-01

    in fast muscle function (power), and accumulation of fat in skeletal muscle. Further HRT raises the protein synthesis rate in skeletal muscle after resistance training, and has an anabolic effect upon connective tissue in both skeletal muscle and tendon, which influences matrix structure and mechanical...... properties. HRT influences gene expression in e.g. cytoskeletal and cell-matrix proteins, has a stimulating effect upon IGF-I, and a role in IL-6 and adipokine regulation. Despite low circulating steroid-hormone level, postmenopausal women have a high local concentration of steroidogenic enzymes in skeletal...

  19. A Case of Tensor Fasciae Suralis Muscle

    OpenAIRE

    Miyauchi, Ryosuke; Kurihara, Kazushige; Tachibana, Gen

    1985-01-01

    An anomalous muscle was found on the dorsum of the right lower limb of a 67-year-old Japanese male. It originated by two heads from the semitendinosus and long head of the biceps femoris and ran distally to insert into the deep surface of the sural fascia. The origin, insertion and location of the muscle were compared with those of the various supernumerary muscles hitherto published. The muscle is consequently regarded as being the tensor fasciae suralis. This is the fifth case in Japan.

  20. Cellular and molecular mechanisms of muscle atrophy

    Directory of Open Access Journals (Sweden)

    Paolo Bonaldo

    2013-01-01

    Full Text Available Skeletal muscle is a plastic organ that is maintained by multiple pathways regulating cell and protein turnover. During muscle atrophy, proteolytic systems are activated, and contractile proteins and organelles are removed, resulting in the shrinkage of muscle fibers. Excessive loss of muscle mass is associated with poor prognosis in several diseases, including myopathies and muscular dystrophies, as well as in systemic disorders such as cancer, diabetes, sepsis and heart failure. Muscle loss also occurs during aging. In this paper, we review the key mechanisms that regulate the turnover of contractile proteins and organelles in muscle tissue, and discuss how impairments in these mechanisms can contribute to muscle atrophy. We also discuss how protein synthesis and degradation are coordinately regulated by signaling pathways that are influenced by mechanical stress, physical activity, and the availability of nutrients and growth factors. Understanding how these pathways regulate muscle mass will provide new therapeutic targets for the prevention and treatment of muscle atrophy in metabolic and neuromuscular diseases.

  1. Update on new muscle glycogenosis

    DEFF Research Database (Denmark)

    Laforêt, Pascal; Malfatti, Edoardo; Vissing, John

    2017-01-01

    and pathological features of the three most recently described muscle glycogenoses caused by recessive mutations in GYG1, RBCK1 and PGM1. The three involved enzymes play different roles in glycogen metabolism. Glycogenin-1 (GYG1) is involved in the initial steps of glycogen synthesis, whereas phosphoglucomutase...... with abnormal storage material in the heart, but most cases present with a polyglucosan body myopathy without cardiac involvement. SUMMARY: The recent identification of new glycogenosis not only allows to improve the knowledge of glycogen metabolism, but also builds bridges with protein glycosylation and immune...

  2. Markov process of muscle motors

    International Nuclear Information System (INIS)

    Kondratiev, Yu; Pechersky, E; Pirogov, S

    2008-01-01

    We study a Markov random process describing muscle molecular motor behaviour. Every motor is either bound up with a thin filament or unbound. In the bound state the motor creates a force proportional to its displacement from the neutral position. In both states the motor spends an exponential time depending on the state. The thin filament moves at a velocity proportional to the average of all displacements of all motors. We assume that the time which a motor stays in the bound state does not depend on its displacement. Then one can find an exact solution of a nonlinear equation appearing in the limit of an infinite number of motors

  3. Relative activity of respiratory muscles during prescribed inspiratory muscle training in healthy people

    OpenAIRE

    Jung, Ju-hyeon; Kim, Nan-soo

    2016-01-01

    [Purpose] This study aimed to determine the effects of different intensities of inspiratory muscle training on the relative respiratory muscle activity in healthy adults. [Subjects and Methods] Thirteen healthy male volunteers were instructed to perform inspiratory muscle training (0%, 40%, 60%, and 80% maximal inspiratory pressure) on the basis of their individual intensities. The inspiratory muscle training was performed in random order of intensities. Surface electromyography data were col...

  4. Muscle MRI Findings in Childhood/Adult Onset Pompe Disease Correlate with Muscle Function.

    Directory of Open Access Journals (Sweden)

    Sebastián Figueroa-Bonaparte

    Full Text Available Enzyme replacement therapy has shown to be effective for childhood/adult onset Pompe disease (AOPD. The discovery of biomarkers useful for monitoring disease progression is one of the priority research topics in Pompe disease. Muscle MRI could be one possible test but the correlation between muscle MRI and muscle strength and function has been only partially addressed so far.We studied 34 AOPD patients using functional scales (Manual Research Council scale, hand held myometry, 6 minutes walking test, timed to up and go test, time to climb up and down 4 steps, time to walk 10 meters and Motor Function Measure 20 Scale, respiratory tests (Forced Vital Capacity seated and lying, Maximun Inspiratory Pressure and Maximum Expiratory Pressure, daily live activities scales (Activlim and quality of life scales (Short Form-36 and Individualized Neuromuscular Quality of Life questionnaire. We performed a whole body muscle MRI using T1w and 3-point Dixon imaging centered on thighs and lower trunk region.T1w whole body muscle MRI showed a homogeneous pattern of muscle involvement that could also be found in pre-symptomatic individuals. We found a strong correlation between muscle strength, muscle functional scales and the degree of muscle fatty replacement in muscle MRI analyzed using T1w and 3-point Dixon imaging studies. Moreover, muscle MRI detected mild degree of fatty replacement in paraspinal muscles in pre-symptomatic patients.Based on our findings, we consider that muscle MRI correlates with muscle function in patients with AOPD and could be useful for diagnosis and follow-up in pre-symptomatic and symptomatic patients under treatment.Muscle MRI correlates with muscle function in patients with AOPD and could be useful to follow-up patients in daily clinic.

  5. The number and choice of muscles impact the results of muscle synergy analyses

    Directory of Open Access Journals (Sweden)

    Katherine Muterspaugh Steele

    2013-08-01

    Full Text Available One theory for how humans control movement is that muscles are activated in weighted groups or synergies. Studies have shown that electromyography (EMG from a variety of tasks can be described by a low-dimensional space thought to reflect synergies. These studies use algorithms, such as nonnegative matrix factorization, to identify synergies from EMG. Due to experimental constraints, EMG can rarely be taken from all muscles involved in a task. However, it is unclear if the choice of muscles included in the analysis impacts estimated synergies. The aim of our study was to evaluate the impact of the number and choice of muscles on synergy analyses. We used a musculoskeletal model to calculate muscle activations required to perform an isometric upper-extremity task. Synergies calculated from the activations from the musculoskeletal model were similar to a prior experimental study. To evaluate the impact of the number of muscles included in the analysis, we randomly selected subsets of between 5 and 29 muscles and compared the similarity of the synergies calculated from each subset to a master set of synergies calculated from all muscles. We determined that the structure of synergies is dependent upon the number and choice of muscles included in the analysis. When five muscles were included in the analysis, the similarity of the synergies to the master set was only 0.57 ± 0.54; however, the similarity improved to over 0.8 with more than ten muscles. We identified two methods, selecting dominant muscles from the master set or selecting muscles with the largest maximum isometric force, which significantly improved similarity to the master set and can help guide future experimental design. Analyses that included a small subset of muscles also over-estimated the variance accounted for (VAF by the synergies compared to an analysis with all muscles. Thus, researchers should use caution using VAF to evaluate synergies when EMG is measured from a small

  6. Sumoylated α-skeletal muscle actin in the skeletal muscle of adult rats.

    Science.gov (United States)

    Uda, Munehiro; Kawasaki, Hiroaki; Iizumi, Kyoichi; Shigenaga, Ayako; Baba, Takeshi; Naito, Hisashi; Yoshioka, Toshitada; Yamakura, Fumiyuki

    2015-11-01

    Skeletal muscles are composed of two major muscle fiber types: slow-twitch oxidative fibers and fast-twitch glycolytic fibers. The proteins in these muscle fibers are known to differ in their expression, relative abundance, and post-translational modifications. In this study, we report a previously unreported post-translational modification of α-skeletal muscle actin in the skeletal muscles of adult male F344 rats in vivo. Using two-dimensional electrophoresis (2D-PAGE), we first examined the differences in the protein expression profiles between the soleus and plantaris muscles. We found higher intensity protein spots at approximately 60 kDa and pH 9 on 2D-PAGE for the soleus muscle compared with the plantaris muscle. These spots were identified as α-skeletal muscle actin by liquid chromatography-nanoelectrospray ionization-tandem mass spectrometry and western blot analyses. In addition, we found that the 60 kDa α-skeletal muscle actin is modified by small ubiquitin-like modifier (SUMO) 1, using 2D-PAGE and western blot analyses. Furthermore, we found that α-skeletal muscle actin with larger molecular weight was localized in the nuclear and cytosol of the skeletal muscle, but not in the myofibrillar fraction by the combination of subcellular fractionation and western blot analyses. These results suggest that α-skeletal muscle actin is modified by SUMO-1 in the skeletal muscles, localized in nuclear and cytosolic fractions, and the extent of this modification is much higher in the slow muscles than in the fast muscles. This is the first study to show the presence of SUMOylated actin in animal tissues.

  7. Muscle-specific GSK-3β ablation accelerates regeneration of disuse-atrophied skeletal muscle.

    Science.gov (United States)

    Pansters, Nicholas A M; Schols, Annemie M W J; Verhees, Koen J P; de Theije, Chiel C; Snepvangers, Frank J; Kelders, Marco C J M; Ubags, Niki D J; Haegens, Astrid; Langen, Ramon C J

    2015-03-01

    Muscle wasting impairs physical performance, increases mortality and reduces medical intervention efficacy in chronic diseases and cancer. Developing proficient intervention strategies requires improved understanding of the molecular mechanisms governing muscle mass wasting and recovery. Involvement of muscle protein- and myonuclear turnover during recovery from muscle atrophy has received limited attention. The insulin-like growth factor (IGF)-I signaling pathway has been implicated in muscle mass regulation. As glycogen synthase kinase 3 (GSK-3) is inhibited by IGF-I signaling, we hypothesized that muscle-specific GSK-3β deletion facilitates the recovery of disuse-atrophied skeletal muscle. Wild-type mice and mice lacking muscle GSK-3β (MGSK-3β KO) were subjected to a hindlimb suspension model of reversible disuse-induced muscle atrophy and followed during recovery. Indices of muscle mass, protein synthesis and proteolysis, and post-natal myogenesis which contribute to myonuclear accretion, were monitored during the reloading of atrophied muscle. Early muscle mass recovery occurred more rapidly in MGSK-3β KO muscle. Reloading-associated changes in muscle protein turnover were not affected by GSK-3β ablation. However, coherent effects were observed in the extent and kinetics of satellite cell activation, proliferation and myogenic differentiation observed during reloading, suggestive of increased myonuclear accretion in regenerating skeletal muscle lacking GSK-3β. This study demonstrates that muscle mass recovery and post-natal myogenesis from disuse-atrophy are accelerated in the absence of GSK-3β. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Low Intensity Vibration as a Treatment for Traumatic Muscle Injury

    Science.gov (United States)

    2016-08-01

    improving muscle healing, thereby reducing joint stiffness and increasing mobility of polytrauma patients. 15. SUBJECT TERMS Skeletal muscle repair ...and increasing mobility of polytrauma patients. 2. KEYWORDS Skeletal muscle repair , low-intensity vibration, monocytes/macrophages, endothelial...areas of bright contrast represent inflammation (indicated by red arrow) and edema within the muscle while darker areas show normal muscle tissue

  9. Glycogen synthesis in human gastrocnemius muscle is not representative of whole-body muscle glycogen synthesis

    NARCIS (Netherlands)

    Serlie, Mireille J. M.; de Haan, Jacco H.; Tack, Cees J.; Verberne, Hein J.; Ackermans, Mariette T.; Heerschap, Arend; Sauerwein, Hans P.

    2005-01-01

    The introduction of C-13 magnetic resonance spectroscopy (MRS) has enabled noninvasive measurement of muscle glycogen synthesis in humans. Conclusions based on measurements by the MRS technique assume that glucose metabolism in gastrocnemius muscle is representative for all skeletal muscles and thus

  10. Glycogen synthesis in human gastrocnemius muscle is not representative of whole-body muscle glycogen synthesis.

    NARCIS (Netherlands)

    Serlie, M.J.; Haan, J.H.A. de; Tack, C.J.J.; Verberne, H.J.; Ackermans, M.T.; Heerschap, A.; Sauerwein, H.P.

    2005-01-01

    The introduction of 13C magnetic resonance spectroscopy (MRS) has enabled noninvasive measurement of muscle glycogen synthesis in humans. Conclusions based on measurements by the MRS technique assume that glucose metabolism in gastrocnemius muscle is representative for all skeletal muscles and thus

  11. Objective evaluation of muscle strength in infants with hypotonia and muscle weakness

    NARCIS (Netherlands)

    Reus, L.; Vlimmeren, L.A. van; Staal, J.B.; Janssen, A.J.W.M.; Otten, B.J.; Pelzer, B.J.; Nijhuis-Van der Sanden, M.W.G.

    2013-01-01

    The clinical evaluation of an infant with motor delay, muscle weakness, and/or hypotonia would improve considerably if muscle strength could be measured objectively and normal reference values were available. The authors developed a method to measure muscle strength in infants and tested 81

  12. Muscle activation during selected strength exercises in women with chronic neck muscle pain

    DEFF Research Database (Denmark)

    Andersen, L.L.; Kjaer, M.; Andersen, C.H.

    2008-01-01

    Background and Purpose. Muscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this stud), was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) (lu...

  13. Zilpaterol hydrochloride affects cellular muscle metabolism and lipid components of ten different muscles in feedlot heifers

    Science.gov (United States)

    This study determined if zilpaterol hydrochloride (ZH) altered muscle metabolism and lipid components of ten muscles. Crossbred heifers were either supplemented with ZH (n = 9) or not (Control; n = 10). Muscle tissue was collected (adductor femoris, biceps femoris, gluteus medius, infraspinatus, lat...

  14. Muscle insulin sensitivity and glucose metabolism are controlled by the intrinsic muscle clock

    DEFF Research Database (Denmark)

    Dyar, Kenneth A.; Ciciliot, Stefano; Wright, Lauren E.

    2014-01-01

    Circadian rhythms control metabolism and energy homeostasis, but the role of the skeletal muscle clock has never been explored. We generated conditional and inducible mouse lines with muscle-specific ablation of the core clock gene Bmal1. Skeletal muscles from these mice showed impaired insulin-s...

  15. Reorganization of muscle synergies during multidirectional reaching in the horizontal plane with experimental muscle pain.

    Science.gov (United States)

    Muceli, Silvia; Falla, Deborah; Farina, Dario

    2014-04-01

    Muscle pain induces a complex reorganization of the motor strategy which cannot be fully explained by current theories. We tested the hypothesis that the neural control of muscles during reaching in the presence of nociceptive input is determined by a reorganization of muscle synergies with respect to control conditions. Muscle pain was induced by injection of hypertonic saline into the anterior deltoid muscle of eight men. Electromyographic (EMG) signals were recorded from 12 upper limb muscles as subjects performed a reaching task before (baseline) and after the injection of hypertonic (pain) saline, and after the pain sensation vanished. The EMG envelopes were factorized in muscle synergies, and activation signals extracted for each condition. Nociceptive stimulation resulted in a complex muscle reorganization without changes in the kinematic output. The anterior deltoid muscle activity decreased in all subjects while the changes in other muscles were subject specific. Three synergies sufficed to describe the EMG patterns in each condition, suggesting that reaching movements remain modular in the presence of experimental pain. Muscle reorganization in all subjects was accompanied by a change in the activation signals compatible with a change in the central drive to muscles. One, two or three synergies were shared between the baseline and painful conditions, depending on the subject. These results indicate that nociceptive stimulation may induce a reorganization of modular control in reaching. We speculate that such reorganization may be due to the recruitment of synergies specific to the painful condition.

  16. Lack of CFTR in skeletal muscle predisposes to muscle wasting and diaphragm muscle pump failure in cystic fibrosis mice.

    Directory of Open Access Journals (Sweden)

    Maziar Divangahi

    2009-07-01

    Full Text Available Cystic fibrosis (CF patients often have reduced mass and strength of skeletal muscles, including the diaphragm, the primary muscle of respiration. Here we show that lack of the CF transmembrane conductance regulator (CFTR plays an intrinsic role in skeletal muscle atrophy and dysfunction. In normal murine and human skeletal muscle, CFTR is expressed and co-localized with sarcoplasmic reticulum-associated proteins. CFTR-deficient myotubes exhibit augmented levels of intracellular calcium after KCl-induced depolarization, and exposure to an inflammatory milieu induces excessive NF-kB translocation and cytokine/chemokine gene upregulation. To determine the effects of an inflammatory environment in vivo, sustained pulmonary infection with Pseudomonas aeruginosa was produced, and under these conditions diaphragmatic force-generating capacity is selectively reduced in Cftr(-/- mice. This is associated with exaggerated pro-inflammatory cytokine expression as well as upregulation of the E3 ubiquitin ligases (MuRF1 and atrogin-1 involved in muscle atrophy. We conclude that an intrinsic alteration of function is linked to the absence of CFTR from skeletal muscle, leading to dysregulated calcium homeostasis, augmented inflammatory/atrophic gene expression signatures, and increased diaphragmatic weakness during pulmonary infection. These findings reveal a previously unrecognized role for CFTR in skeletal muscle function that may have major implications for the pathogenesis of cachexia and respiratory muscle pump failure in CF patients.

  17. Resistance training induces qualitative changes in muscle morphology, muscle architecture, and muscle function in elderly postoperative patients

    DEFF Research Database (Denmark)

    Suetta, Charlotte; Andersen, Jesper L; Dalgas, Ulrik

    2008-01-01

    Although the negative effects of bed rest on muscle strength and muscle mass are well established, it still remains a challenge to identify effective methods to restore physical capacity of elderly patients recovering from hospitalization. The present study compared different training regimes...... degrees /s (P thickness increased by 15% (P

  18. Exercise-Associated Muscle Cramps

    Science.gov (United States)

    Miller, Kevin C.; Stone, Marcus S.; Huxel, Kellie C.; Edwards, Jeffrey E.

    2010-01-01

    Context: Exercise-associated muscle cramps (EAMC) are a common condition experienced by recreational and competitive athletes. Despite their commonality and prevalence, their cause remains unknown. Theories for the cause of EAMC are primarily based on anecdotal and observational studies rather than sound experimental evidence. Without a clear cause, treatments and prevention strategies for EAMC are often unsuccessful. Evidence Acquisition: A search of Medline (EBSCO), SPORTDiscus, and Silverplatter (CINHAL) was undertaken for journal articles written in English between the years 1955 and 2008. Additional references were collected by a careful analysis of the citations of others’ research and textbooks. Results: Dehydration/electrolyte and neuromuscular causes are the most widely discussed theories for the cause of EAMC; however, strong experimental evidence for either theory is lacking. Conclusions: EAMC are likely due to several factors coalescing to cause EAMC. The variety of treatments and prevention strategies for EAMC are evidence of the uncertainty in their cause. Acute EAMC treatment should focus on moderate static stretching of the affected muscle followed by a proper medical history to determine any predisposing conditions that may have triggered the onset of EAMC. Based on physical findings, prevention programs should be implemented to include fluid and electrolyte balance strategies and/or neuromuscular training. PMID:23015948

  19. Muscle GLUT4 in cirrhosis

    DEFF Research Database (Denmark)

    Holland-Fischer, Peter; Andersen, Per Heden; Lund, Sten

    2007-01-01

    BACKGROUND/AIMS: The insulin-dependent glucose transporter GLUT4 mediates 50-80% of whole body glucose uptake, but its relation to the frequent glucose intolerance in patients with liver cirrhosis is unknown. METHODS: Thirty patients and seven healthy controls underwent a 2-h oral glucose tolerance...... test and later a muscle biopsy. Levels of GLUT4 total protein and mRNA content were determined in muscle biopsies by polyclonal antibody labelling and RT-PCR, respectively. RESULTS: GLUT4 protein content in the cirrhosis group was not different from that of the controls, but at variance...... with the control subjects it correlated closely with measures of glucose tolerance (R(2)=0.45; p=0.003). GLUT4 mRNA of the patients with cirrhosis was reduced to 56% of control value (95% ci: 27-86%; p=0.015) and was inversely related to the level of basal hyper-insulinemia (R(2)=0.39; p=0.004). CONCLUSIONS...

  20. Muscle GLUT4 in cirrhosis

    DEFF Research Database (Denmark)

    Holland-Fischer, Peter; Andersen, Per Heden; Lund, Sten

    2007-01-01

    BACKGROUND/AIMS: The insulin-dependent glucose transporter GLUT4 mediates 50-80% of whole body glucose uptake, but its relation to the frequent glucose intolerance in patients with liver cirrhosis is unknown. METHODS: Thirty patients and seven healthy controls underwent a 2-h oral glucose tolerance...... test and later a muscle biopsy. Levels of GLUT4 total protein and mRNA content were determined in muscle biopsies by polyclonal antibody labelling and RT-PCR, respectively. RESULTS: GLUT4 protein content in the cirrhosis group was not different from that of the controls, but at variance...... with the control subjects it correlated closely with measures of glucose tolerance (R(2)=0.45; p=0.003). GLUT4 mRNA of the cirrhosis patients was reduced to 56% of control value (95% ci: 27-86%; p=0.015) and was inversely related to the level of basal hyper-insulinemia (R(2)=0.39; p=0.004). CONCLUSIONS...

  1. Gender differences in MR muscle tractography

    International Nuclear Information System (INIS)

    Okamoto, Yoshikazu; Minami, Manabu; Kunimatsu, Akira; Kono, Tatsuo; Sonobe, Jyunichi; Kujiraoka, Yuka

    2010-01-01

    Tractography of skeletal muscle can clearly reveal the 3-dimensional course of muscle fibers, and the procedure has great potential and could open new fields for diagnostic imaging. Studying this technique for clinical application, we noticed differences in the number of visualized tracts among volunteers and among muscles in the same volunteer. To comprehend why the number of visualized tracts varied so that we could acquire consistently high quality tractography of muscle fiber, we started to examine whether differences in individual parameters affected tractography visualization. The purpose of this study was to determine whether there are gender- and age-specific differences that differentiate the muscles by gender and age in MR tractography of skeletal muscle fiber. We divided 33 healthy volunteers by gender and age among 3 groups, A (13 younger men, aged 20 to 36 years), B (11 younger women, 25 to 39 years), and C (9 older men, 50 to 69), and we obtained from each volunteer tractographs of 8 fibers, including the bilateral gastrocnemius medialis (GCM), gastrocnemius lateralis (GCL), soleus (SOL), and anterior tibialis (AT) muscles. We classified the fibers into 5 grades depending on the extent of visualized tracts and used Mann-Whitney U-test to compare scores by gender (Group A versus B) and age (Group A versus C). Muscle tracts were significantly better visualized in women than men (median total visual score, 34 versus 24, P<0.05). In particular, the SOL muscles showed better visualization in the right (4.0 in women, 1.0 in men, P<0.05) and left (3.0 in women, 1.0 in men, P<0.05). Difference by age was not significant. The GCL was the highest scored muscle in all groups. Our results suggest that group differences, especially by gender, affected visualization of tractography of muscle fiber of the calf. (author)

  2. Regulatory T cells and skeletal muscle regeneration.

    Science.gov (United States)

    Schiaffino, Stefano; Pereira, Marcelo G; Ciciliot, Stefano; Rovere-Querini, Patrizia

    2017-02-01

    Skeletal muscle regeneration results from the activation and differentiation of myogenic stem cells, called satellite cells, located beneath the basal lamina of the muscle fibers. Inflammatory and immune cells have a crucial role in the regeneration process. Acute muscle injury causes an immediate transient wave of neutrophils followed by a more persistent infiltration of M1 (proinflammatory) and M2 (anti-inflammatory/proregenerative) macrophages. New studies show that injured muscle is also infiltrated by a specialized population of regulatory T (Treg) cells, which control both the inflammatory response, by promoting the M1-to-M2 switch, and the activation of satellite cells. Treg cells accumulate in injured muscle in response to specific cytokines, such as IL-33, and promote muscle growth by releasing growth factors, such as amphiregulin. Muscle repair during aging is impaired due to reduced number of Treg cells and can be enhanced by IL-33 supplementation. Migration of Treg cells could also contribute to explain the effect of heterochronic parabiosis, whereby muscle regeneration of aged mice can be improved by a parabiotically linked young partners. In mdx dystrophin-deficient mice, a model of human Duchenne muscular dystrophy, muscle injury, and inflammation is mitigated by expansion of the Treg-cell population but exacerbated by Treg-cell depletion. These findings support the notion that immunological mechanisms are not only essential in the response to pathogenic microbes and tumor cells but also have a wider homeostatic role in tissue repair, and open new perspectives for boosting muscle growth in chronic muscle disease and during aging. © 2016 Federation of European Biochemical Societies.

  3. The surface electromyography analysis of the non-plegic upper limb of hemiplegic subjects Análise da eletromiografia de superfície do membro superior não plégico de hemiplégicos

    Directory of Open Access Journals (Sweden)

    Heloyse U Kuriki

    2010-08-01

    Full Text Available Many authors have studied physical and functional changes in individuals post-stroke, but there are few studies that assess changes in the non-plegic side of hemiplegic subjects. This study aimed to compare the electromyographic activity in the forearm muscles of spastic patients and clinically healthy individuals, to determine if there is difference between the non-plegic side of hemiplegics and the dominant member of normal individuals. 22 hemiplegic subjects and 15 clinically healthy subjects were submitted to electromyography of the flexor and extensor carpi ulnaris muscles during wrist flexion and extension. The flexor muscles activation of stroke group (average 464.6 u.n was significantly higher than the same muscles in control group (mean: 106.3 u.n. during the wrist flexion, what shows that the non affected side does not present activation in the standart of normality found in the control group.Muitos autores estudaram as modificações funcionais e físicas em indivíduos pós-acidente vascular cerebral; porém, poucos estudos avaliam alterações no hemicorpo não plégico de indivíduos hemiplégicos. O objetivo deste estudo foi comparar a atividade eletromiográfica nos músculos do antebraço de pacientes espásticos e indivíduos clinicamente saudáveis, para averiguar se há diferença entre o lado não plégico de indivíduos hemiplégicos e o lado dominante de indivíduos clinicamente saudáveis. 22 indivíduos hemiplégicos e 15 clinicamente saudáveis foram submetidos à eletromiografia dos músculos flexor e extensor ulnar do carpo durante a flexão e extensão do punho. A ativação dos músculos flexores dos hemiplégicos (média: 464,6 u.n, foi significantemente maior que nos indivíduos do grupo controle (média: 106,3 u.n durante o movimento de flexão do punho, o que demonstra que o hemicorpo não acometido dos pacientes estudados não apresenta o comportamento padrão de normalidade encontrado no grupo controle.

  4. Muscle type-specific responses to NAD+ salvage biosynthesis promote muscle function in Caenorhabditis elegans.

    Science.gov (United States)

    Vrablik, Tracy L; Wang, Wenqing; Upadhyay, Awani; Hanna-Rose, Wendy

    2011-01-15

    Salvage biosynthesis of nicotinamide adenine dinucleotide (NAD(+)) from nicotinamide (NAM) lowers NAM levels and replenishes the critical molecule NAD(+) after it is hydrolyzed. This pathway is emerging as a regulator of multiple biological processes. Here we probe the contribution of the NAM-NAD(+) salvage pathway to muscle development and function using Caenorhabditis elegans. C. elegans males with mutations in the nicotinamidase pnc-1, which catalyzes the first step of this NAD(+) salvage pathway, cannot mate due to a spicule muscle defect. Multiple muscle types are impaired in the hermaphrodites, including body wall muscles, pharyngeal muscles and vulval muscles. An active NAD(+) salvage pathway is required for optimal function of each muscle cell type. However, we found surprising muscle-cell-type specificity in terms of both the timing and relative sensitivity to perturbation of NAD(+) production or NAM levels. Active NAD(+) biosynthesis during development is critical for function of the male spicule protractor muscles during adulthood, but these muscles can surprisingly do without salvage biosynthesis in adulthood under the conditions examined. The body wall muscles require ongoing NAD(+) salvage biosynthesis both during development and adulthood for maximum function. The vulval muscles do not function in the presence of elevated NAM concentrations, but NAM supplementation is only slightly deleterious to body wall muscles during development or upon acute application in adults. Thus, the pathway plays distinct roles in different tissues. As NAM-NAD(+) biosynthesis also impacts muscle differentiation in vertebrates, we propose that similar complexities may be found among vertebrate muscle cell types. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Effect of repeated forearm muscle cooling on the adaptation of skeletal muscle metabolism in humans

    Science.gov (United States)

    Wakabayashi, Hitoshi; Nishimura, Takayuki; Wijayanto, Titis; Watanuki, Shigeki; Tochihara, Yutaka

    2017-07-01

    This study aimed to investigate the effect of repeated cooling of forearm muscle on adaptation in skeletal muscle metabolism. It is hypothesized that repeated decreases of muscle temperature would increase the oxygen consumption in hypothermic skeletal muscle. Sixteen healthy males participated in this study. Their right forearm muscles were locally cooled to 25 °C by cooling pads attached to the skin. This local cooling was repeated eight times on separate days for eight participants (experimental group), whereas eight controls received no cold exposure. To evaluate adaptation in skeletal muscle metabolism, a local cooling test was conducted before and after the repeated cooling period. Change in oxy-hemoglobin content in the flexor digitorum at rest and during a 25-s isometric handgrip (10% maximal voluntary construction) was measured using near-infrared spectroscopy at every 2 °C reduction in forearm muscle temperature. The arterial blood flow was occluded for 15 s by upper arm cuff inflation at rest and during the isometric handgrip. The oxygen consumption in the flexor digitorum muscle was evaluated by a slope of the oxy-hemoglobin change during the arterial occlusion. In the experimental group, resting oxygen consumption in skeletal muscle did not show any difference between pre- and post-intervention, whereas muscle oxygen consumption during the isometric handgrip was significantly higher in post-intervention than in pre-test from thermoneutral baseline to 31 °C muscle temperature ( P < 0.05). This result indicated that repeated local muscle cooling might facilitate oxidative metabolism in the skeletal muscle. In summary, skeletal muscle metabolism during submaximal isometric handgrip was facilitated after repeated local muscle cooling.

  6. Muscle-specific expression of hypoxia-inducible factor in human skeletal muscle

    DEFF Research Database (Denmark)

    Mounier, Rémi; Pedersen, Bente Klarlund; Plomgaard, Peter

    2010-01-01

    Skeletal muscle is well known to exhibit a high degree of plasticity depending on environmental changes, such as various oxygen concentrations. Studies of the oxygen-sensitive subunit alpha of hypoxia-inducible factor-1 (HIF-1) are difficult owing to the large variety of functionally diverse muscle......alpha protein level. Interestingly, none of the HIF-1alpha target genes, like the most studied angiogenic factor involved in muscle angiogenesis, vascular endothelial growth factor (VEGF), exhibited a muscle fibre-specific-related mRNA expression at rest in normoxia. However, soleus presented...... here, support a key role for HIF-1alpha for maintaining muscle homeostasis in non-hypoxic conditions....

  7. Changes in muscle strength and morphology after muscle unloading in Special Forces missions

    DEFF Research Database (Denmark)

    Thorlund, J B; Jakobsen, O; Madsen, T

    2011-01-01

    The purpose of the present study was to determine the changes in maximal muscle strength, rapid force capacity, jumping performance and muscle morphology following a Special Forces military operation involving 8 days of muscle unloading. Nine male Special Forces soldiers were tested before (pre......) and immediately after (post1) an 8-day simulated special support and reconnaissance (SSR) mission and after 3 h of active recovery (post2). Maximal muscle strength (MVC) and rate of force development (RFD) were measured along with maximal counter movement jump height (JH). Muscle biopsies were obtained from...

  8. Genetics Home Reference: myostatin-related muscle hypertrophy

    Science.gov (United States)

    ... Conditions Myostatin-related muscle hypertrophy Myostatin-related muscle hypertrophy Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description Myostatin-related muscle hypertrophy is a rare condition characterized by reduced body ...

  9. Proteomic signature of muscle atrophy in rainbow trout

    Science.gov (United States)

    Muscle deterioration arises as a physiological response to elevated energetic demands of fish sexual maturation and spawning. Previously, we used this model to characterize the transcriptomic mechanisms associated with muscle degradation in fish and identified potential biological markers of muscle...

  10. Autosomal Recessive Myotonia Congenita, A Muscle ...

    African Journals Online (AJOL)

    Background: The muscle diseases are frequently encountered in medical clinics in Nigeria. In many cases however they are not optimally managed. The ion channel diseases, 'channelopathies', are a group of muscle disorders that share a lot of clinical similarity. Misdiagnosis can occur especially in resource poor settings ...

  11. Genetics Home Reference: rippling muscle disease

    Science.gov (United States)

    ... JP, Fricke B, Meinck HM, Torbergsen T, Engels H, Voss B, Vorgerd M. Homozygous mutations in caveolin-3 cause a severe form of rippling muscle disease. Ann Neurol. 2003 Apr;53(4):512-20. Citation on PubMed Lamb GD. Rippling muscle disease may be caused by " ...

  12. Lower limb asymmetry in mechanical muscle function

    DEFF Research Database (Denmark)

    Jordan, M J; Aagaard, Per; Herzog, W

    2015-01-01

    ) for kinetic impulse (CMJ and SJ phase-specific kinetic impulse AI). Dual x-ray absorptiometry scanning was used to assess asymmetry in lower body muscle mass. Compared with controls, ACL-R skiers had increased AI in muscle mass (P 

  13. Respiratory muscle training in Duchenne muscular dystrophy.

    OpenAIRE

    Rodillo, E; Noble-Jamieson, C M; Aber, V; Heckmatt, J Z; Muntoni, F; Dubowitz, V

    1989-01-01

    Twenty two boys with Duchenne muscular dystrophy were entered into a randomised double blind crossover trial to compare respiratory muscle training with a Triflow II inspirometer and 'placebo' training with a mini peak flow meter. Supine posture was associated with significantly impaired lung function, but respiratory muscle training showed no benefit.

  14. Bone muscle interactions and vitamin D

    NARCIS (Netherlands)

    Gunton, J.E.; Girgis, C.M.; Baldock, P.A.; Lips, P.

    2015-01-01

    Beyond the established roles of vitamin D in bone and mineral homeostasis, we are becoming increasingly aware of its diverse effects in skeletal muscle. Subjects with severe vitamin D deficiency or mutations of the vitamin D receptor develop generalized atrophy of muscle and bone, suggesting

  15. Neuromuscular imaging in inherited muscle diseases

    International Nuclear Information System (INIS)

    Wattjes, Mike P.; Kley, Rudolf A.; Fischer, Dirk

    2010-01-01

    Driven by increasing numbers of newly identified genetic defects and new insights into the field of inherited muscle diseases, neuromuscular imaging in general and magnetic resonance imaging (MRI) in particular are increasingly being used to characterise the severity and pattern of muscle involvement. Although muscle biopsy is still the gold standard for the establishment of the definitive diagnosis, muscular imaging is an important diagnostic tool for the detection and quantification of dystrophic changes during the clinical workup of patients with hereditary muscle diseases. MRI is frequently used to describe muscle involvement patterns, which aids in narrowing of the differential diagnosis and distinguishing between dystrophic and non-dystrophic diseases. Recent work has demonstrated the usefulness of muscle imaging for the detection of specific congenital myopathies, mainly for the identification of the underlying genetic defect in core and centronuclear myopathies. Muscle imaging demonstrates characteristic patterns, which can be helpful for the differentiation of individual limb girdle muscular dystrophies. The aim of this review is to give a comprehensive overview of current methods and applications as well as future perspectives in the field of neuromuscular imaging in inherited muscle diseases. We also provide diagnostic algorithms that might guide us through the differential diagnosis in hereditary myopathies. (orig.)

  16. Neuromuscular imaging in inherited muscle diseases

    Energy Technology Data Exchange (ETDEWEB)

    Wattjes, Mike P. [VU University Medical Center, Department of Radiology, De Boelelaan 1117, HV, Amsterdam (Netherlands); Kley, Rudolf A. [Klinken Bergmannsheil, Ruhr-University, Department of Neurology, Neuromuscular Centre Ruhrgebiet, Bochum (Germany); Fischer, Dirk [University Hospital of Basel, Department of Neurology, Basel (Switzerland); University Children' s Hospital Basel, Department of Neuropaediatrics, Basel (Switzerland)

    2010-10-15

    Driven by increasing numbers of newly identified genetic defects and new insights into the field of inherited muscle diseases, neuromuscular imaging in general and magnetic resonance imaging (MRI) in particular are increasingly being used to characterise the severity and pattern of muscle involvement. Although muscle biopsy is still the gold standard for the establishment of the definitive diagnosis, muscular imaging is an important diagnostic tool for the detection and quantification of dystrophic changes during the clinical workup of patients with hereditary muscle diseases. MRI is frequently used to describe muscle involvement patterns, which aids in narrowing of the differential diagnosis and distinguishing between dystrophic and non-dystrophic diseases. Recent work has demonstrated the usefulness of muscle imaging for the detection of specific congenital myopathies, mainly for the identification of the underlying genetic defect in core and centronuclear myopathies. Muscle imaging demonstrates characteristic patterns, which can be helpful for the differentiation of individual limb girdle muscular dystrophies. The aim of this review is to give a comprehensive overview of current methods and applications as well as future perspectives in the field of neuromuscular imaging in inherited muscle diseases. We also provide diagnostic algorithms that might guide us through the differential diagnosis in hereditary myopathies. (orig.)

  17. Interleukin-6 myokine signaling in skeletal muscle

    DEFF Research Database (Denmark)

    Muñoz-Cánoves, Pura; Scheele, Camilla; Pedersen, Bente K

    2013-01-01

    Interleukin (IL)-6 is a cytokine with pleiotropic functions in different tissues and organs. Skeletal muscle produces and releases significant levels of IL-6 after prolonged exercise and is therefore considered as a myokine. Muscle is also an important target of the cytokine. IL-6 signaling has...

  18. Electrical stimulation counteracts muscle decline in seniors.

    Science.gov (United States)

    Kern, Helmut; Barberi, Laura; Löfler, Stefan; Sbardella, Simona; Burggraf, Samantha; Fruhmann, Hannah; Carraro, Ugo; Mosole, Simone; Sarabon, Nejc; Vogelauer, Michael; Mayr, Winfried; Krenn, Matthias; Cvecka, Jan; Romanello, Vanina; Pietrangelo, Laura; Protasi, Feliciano; Sandri, Marco; Zampieri, Sandra; Musaro, Antonio

    2014-01-01

    The loss in muscle mass coupled with a decrease in specific force and shift in fiber composition are hallmarks of aging. Training and regular exercise attenuate the signs of sarcopenia. However, pathologic conditions limit the ability to perform physical exercise. We addressed whether electrical stimulation (ES) is an alternative intervention to improve muscle recovery and defined the molecular mechanism associated with improvement in muscle structure and function. We analyzed, at functional, structural, and molecular level, the effects of ES training on healthy seniors with normal life style, without routine sport activity. ES was able to improve muscle torque and functional performances of seniors and increased the size of fast muscle fibers. At molecular level, ES induced up-regulation of IGF-1 and modulation of MuRF-1, a muscle-specific atrophy-related gene. ES also induced up-regulation of relevant markers of differentiating satellite cells and of extracellular matrix remodeling, which might guarantee shape and mechanical forces of trained skeletal muscle as well as maintenance of satellite cell function, reducing fibrosis. Our data provide evidence that ES is a safe method to counteract muscle decline associated with aging.

  19. 38 CFR 4.78 - Muscle function.

    Science.gov (United States)

    2010-07-01

    ... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected... DISABILITIES Disability Ratings The Organs of Special Sense § 4.78 Muscle function. (a) Examination of muscle...

  20. Thyroid hormones and muscle metabolism in dogs.

    Science.gov (United States)

    Kruk, B; Brzezinska, Z; Kaciuba-Uscilko, H; Nazar, K

    1988-10-01

    Muscle contents of ATP, ADP, AMP, creatine phosphate and creatine as well as glycogen, some glycolytic intermediates, pyruvate and lactate were compared in the intact, thyroidectomized and triiodothyronine (T3) treated dogs under resting conditions. After thyroidectomy muscle glycogen, glucose 1-phosphate and glucose 6-phosphate contents were significantly elevated while in T3-treated animals these variables were decreased in comparison with control dogs. Muscle free glucose was not altered by thyroidectomy but T3 treatment significantly increased its content. Muscle lactate content was elevated both in hypo- and hyperthyroid animals. Muscle ATP and total adenine nucleotide contents were significantly increased in hyperthyroid dogs while no differences were found between the three groups in the muscle creatine phosphate content. It is assumed that in T3-treated animals carbohydrate catabolism is enhanced in the resting skeletal muscle in spite of high tissue ATP content. Muscle metabolite alterations in hypothyroid dogs seem to reflect the hypometabolism accompanied by a diminished rate of glycogenolysis with inhibited rate of pyruvate oxidation or decreased rate of lactate removal from the cells.

  1. Calpain 3 is important for muscle regeneration

    DEFF Research Database (Denmark)

    Hauerslev, Simon; Sveen, Marie-Louise; Duno, Morten

    2012-01-01

    Limb girdle muscular dystrophy (LGMD) type 2A is caused by mutations in the CAPN3 gene and complete lack of functional calpain 3 leads to the most severe muscle wasting. Calpain 3 is suggested to be involved in maturation of contractile elements after muscle degeneration. The aim of this study...

  2. Quantitative phosphoproteomic analysis of postmortem muscle development

    DEFF Research Database (Denmark)

    Huang, Honggang

    and myofibrillar proteins from PM porcine muscle. Generally, the porcine muscle with fast pH decline rate had the highest phosphorylation level at 1 h PM, but lowest at 24 h PM, whereas the group with slow pH decline rate showed the reverse case. The protein phosphorylation level of sarcoplasmic proteins...

  3. A rare variation of the digastric muscle

    Science.gov (United States)

    KALNIEV, MANOL; KRASTEV, DIMO; KRASTEV, NIKOLAY; VIDINOV, KALIN; VELTCHEV, LUDMIL; APOSTOLOV, ALEXANDER; MILEVA, MILKA

    2013-01-01

    The digastric muscle is composed by two muscle bellies: an anterior and a posterior, joined by an intermediate tendon. This muscle is situated in the anterior region of the neck. The region between the hyoid bone and the mandible is divided by an anterior belly into two triangles: the submandibular situated laterally and the submental triangle which is located medially. We found that the anatomical variations described in the literature relate mainly to the anterior belly and consist of differences in shape and attachment of the muscle. During routine dissection in February 2013 in the section hall of the Department of Anatomy and Histology in Medical University – Sofia we came across a very interesting variation of the digastric muscle. The digastric muscles that presented anatomical variations were photographed using a Sony Cyber-shot DSC-T1 camera, with a Carl Zeiss Vario-Tessar lens. We found out bilateral variation of the digastric muscle in one cadaver. The anterior bellies were very thin and insert to the hyoid bone. Two anterior bellies connect each other and thus they formed a loop. The anatomical variations observed of our study related only to the anterior belly, as previously described by other authors. It is very important to consider the occurrence of the above mentioned variations in the digastric muscle when surgical procedures are performed on the anterior region of the neck. PMID:26527971

  4. Muscle activation patterns in posttraumatic neck pain

    NARCIS (Netherlands)

    Nederhand, Marcus Johannes

    2003-01-01

    As an important consequence of our research, we question the relevance of the criteria of the WAD injury severity classification system. We showed that the musculoskeletal signs in WAD grade II are not characterized by muscle spasm, (i.e. increase of muscle activity), but rather by a decrease in

  5. Proficiency test for paracitides in salmon muscle

    NARCIS (Netherlands)

    Elbers, I.J.W.

    2012-01-01

    The aim of this proficiency study was to give laboratories the possibility to evaluate or demonstrate their competence for the analysis of parasiticides in salmon muscle. This study also provided an evaluation of the methods applied for the quantitative analysis of parasiticides in salmon muscle.

  6. Sympathetic actions on the skeletal muscle.

    Science.gov (United States)

    Roatta, Silvestro; Farina, Dario

    2010-01-01

    The sympathetic nervous system (SNS) modulates several functions in skeletal muscle fibers, including metabolism, ionic transport across the membrane, and contractility. These actions, together with the sympathetic control of other organ systems, support intense motor activity. However, some SNS actions on skeletal muscles may not always be functionally advantageous. Implications for motor control and sport performance are discussed.

  7. Regulation of skeletal muscle glycogenolysis during exercise

    DEFF Research Database (Denmark)

    Hargreaves, M; Richter, Erik

    1988-01-01

    Muscle-glycogen breakdown during exercise is influenced by both local and systemic factors. Contractions per se increase glycogenolysis via a calcium-induced, transient increase in the activity of phosphorylase a, and probably also via increased concentrations of Pi. In fast-twitch muscle...

  8. Inspiratory muscle training increases inspiratory muscle strength in patients weaning from mechanical ventilation: a systematic review.

    Science.gov (United States)

    Moodie, Lisa; Reeve, Julie; Elkins, Mark

    2011-01-01

    Does inspiratory muscle training improve inspiratory muscle strength and endurance, facilitate weaning, improve survival, and reduce the rate of reintubation and tracheostomy in adults receiving mechanical ventilation? Systematic review of randomised or quasi-randomised controlled trials. Adults over 16 years of age receiving mechanical ventilation. Inspiratory muscle training versus sham or no inspiratory muscle training. Data were extracted regarding inspiratory muscle strength and endurance, the duration of unassisted breathing periods, weaning success and duration, reintubation and tracheostomy, survival, adverse effects, and length of stay. Three studies involving 150 participants were included in the review. The studies varied in time to commencement of the training, the device used, the training protocol, and the outcomes measured. Inspiratory muscle training significantly increased inspiratory muscle strength over sham or no training (weighted mean difference 8 cmH(2)O, 95% CI 6 to 9). There were no statistically significant differences between the groups in weaning success or duration, survival, reintubation, or tracheostomy. Inspiratory muscle training was found to significantly increase inspiratory muscle strength in adults undergoing mechanical ventilation. Despite data from a substantial pooled cohort, it is not yet clear whether the increase in inspiratory muscle strength leads to a shorter duration of mechanical ventilation, improved weaning success, or improved survival. Further large randomised studies are required to clarify the impact of inspiratory muscle training on patients receiving mechanical ventilation. PROSPERO CRD42011001132. Copyright © 2011 Australian Physiotherapy Association. Published by .. All rights reserved.

  9. Changes in predicted muscle coordination with subject-specific muscle parameters for individuals after stroke.

    Science.gov (United States)

    Knarr, Brian A; Reisman, Darcy S; Binder-Macleod, Stuart A; Higginson, Jill S

    2014-01-01

    Muscle weakness is commonly seen in individuals after stroke, characterized by lower forces during a maximal volitional contraction. Accurate quantification of muscle weakness is paramount when evaluating individual performance and response to after stroke rehabilitation. The objective of this study was to examine the effect of subject-specific muscle force and activation deficits on predicted muscle coordination when using musculoskeletal models for individuals after stroke. Maximum force generating ability and central activation ratio of the paretic plantar flexors, dorsiflexors, and quadriceps muscle groups were obtained using burst superimposition for four individuals after stroke with a range of walking speeds. Two models were created per subject: one with generic and one with subject-specific activation and maximum isometric force parameters. The inclusion of subject-specific muscle data resulted in changes in the model-predicted muscle forces and activations which agree with previously reported compensation patterns and match more closely the timing of electromyography for the plantar flexor and hamstring muscles. This was the first study to create musculoskeletal simulations of individuals after stroke with subject-specific muscle force and activation data. The results of this study suggest that subject-specific muscle force and activation data enhance the ability of musculoskeletal simulations to accurately predict muscle coordination in individuals after stroke.

  10. Association of muscle hardness with muscle tension dynamics: a physiological property.

    Science.gov (United States)

    Murayama, Mitsuyoshi; Watanabe, Kotaro; Kato, Ryoko; Uchiyama, Takanori; Yoneda, Tsugutake

    2012-01-01

    This study aimed to investigate the relationship between muscle hardness and muscle tension in terms of length-tension relationship. A frog gastrocnemius muscle sample was horizontally mounted on the base plate inside a chamber and was stretched from 100 to 150% of the pre-length, in 5% increments. After each step of muscle lengthening, electrical field stimulation for induction of tetanus was applied using platinum-plate electrodes positioned on either side of the muscle submerged in Ringer's solution. The measurement of muscle hardness, i.e., applying perpendicular distortion, was performed whilst maintaining the plateau of passive and tetanic tension. The relationship between normalised tension and normalised muscle hardness was evaluated. The length-hardness diagram could be created from the modification with the length-tension diagram. It is noteworthy that muscle hardness was proportional to passive and total tension. Regression analysis revealed a significant correlation between muscle hardness and passive and total tension, with a significant positive slope (passive tension: r = 0.986, P hardness depends on muscle tension in most ranges of muscle length in the length-tension diagram.

  11. Denervation of rabbit gastrocnemius and soleus muscles: effect on muscle-specific enolase.

    Science.gov (United States)

    Nozais, M; Merkulova, T; Keller, A; Janmot, C; Lompré, A M; D'Albis, A; Lucas, M

    1999-07-01

    We report here, for the first time, the expression of the muscle-specific isoform of the glycolytic enzyme, enolase (EC 4.2.1. 11) (beta enolase), in rabbit skeletal muscles. We have analysed the fast-twitch gastrocnemius and the slow-twitch soleus muscles during normal postnatal development and following denervation. We show that, in rabbit, as already described in rodents, beta enolase gene expression behaves as a good marker of the fast-twitch fibers. In soleus muscle, the beta enolase transcript level is 10-20% of that found in gastrocnemius. Denervation, performed at 8 postnatal days, induces an important drop of beta enolase transcript levels in both developing soleus and gastrocnemius muscles, with a 80% decrease observed 1 week after denervation in the operated muscles, as compared to the corresponding contralateral muscles. Thereafter, the beta enolase transcript level continues to decrease in the fast-twitch muscle, with the beta enolase subunit being detectable only in the atrophic fast-twitch fibers. In contrast, the beta transcript level tends to increase in the denervated slow-twitch muscle, reaching about 50% of that in contralateral soleus, at 7 weeks after surgery. The level of beta enolase transcripts still expressed after denervation seems to stabilize at the same low level in both types of inactive muscles. This suggests that the small fraction of beta enolase expression which is not controlled by the nerve, or by the contractile activity imposed by it, is independent of the muscle phenotype.

  12. LEGS AND TRUNK MUSCLE HYPERTROPHY FOLLOWING WALK TRAINING WITH RESTRICTED LEG MUSCLE BLOOD FLOW

    Directory of Open Access Journals (Sweden)

    Mikako Sakamaki

    2011-06-01

    Full Text Available We examined the effect of walk training combined with blood flow restriction (BFR on the size of blood flow-restricted distal muscles, as well as, on the size of non-restricted muscles in the proximal limb and trunk. Nine men performed walk training with BFR and 8 men performed walk training alone. Training was conducted two times a day, 6 days/wk, for 3 wk using five sets of 2-min bouts (treadmill speed at 50 m/min, with a 1-min rest between bouts. After walk training with BFR, MRI-measured upper (3.8%, P < 0.05 and lower leg (3.2%, P < 0. 05 muscle volume increased significantly, whereas the muscle volume of the gluteus maximus (-0.6% and iliopsoas (1.8% and the muscle CSA of the lumber L4-L5 (-1.0 did not change. There was no significant change in muscle volume in the walk training alone. Our results suggest that the combination of leg muscle blood flow restriction with slow walk training elicits hypertrophy only in the distal blood flow restricted leg muscles. Exercise intensity may be too low during BFR walk training to increase muscle mass in the non- blood flow restricted muscles (gluteus maximus and other trunk muscles.

  13. Electric pulse stimulation of cultured murine muscle cells reproduces gene expression changes of trained mouse muscle.

    Directory of Open Access Journals (Sweden)

    Nathalie Burch

    2010-06-01

    Full Text Available Adequate levels of physical activity are at the center of a healthy lifestyle. However, the molecular mechanisms that mediate the beneficial effects of exercise remain enigmatic. This gap in knowledge is caused by the lack of an amenable experimental model system. Therefore, we optimized electric pulse stimulation of muscle cells to closely recapitulate the plastic changes in gene expression observed in a trained skeletal muscle. The exact experimental conditions were established using the peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha as a marker for an endurance-trained muscle fiber. We subsequently compared the changes in the relative expression of metabolic and myofibrillar genes in the muscle cell system with those observed in mouse muscle in vivo following either an acute or repeated bouts of treadmill exercise. Importantly, in electrically stimulated C2C12 mouse muscle cells, the qualitative transcriptional adaptations were almost identical to those in trained muscle, but differ from the acute effects of exercise on muscle gene expression. In addition, significant alterations in the expression of myofibrillar proteins indicate that this stimulation could be used to modulate the fiber-type of muscle cells in culture. Our data thus describe an experimental cell culture model for the study of at least some of the transcriptional aspects of skeletal muscle adaptation to physical activity. This system will be useful for the study of the molecular mechanisms that regulate exercise adaptation in muscle.

  14. Comparative transcriptome analysis of fast twitch muscle and slow twitch muscle in Takifugu rubripes.

    Science.gov (United States)

    Gao, Kailun; Wang, Zhicheng; Zhou, Xiaoxu; Wang, Haoze; Kong, Derong; Jiang, Chen; Wang, Xiuli; Jiang, Zhiqiang; Qiu, Xuemei

    2017-12-01

    Fast twitch muscle and slow twitch muscle are two important organs of Takifugu rubripes. Both tissues are of ectodermic origin, and the differences between the two muscle fibers reflect the differences in their myofibril protein composition and molecular structure. In order to identify and characterize the gene expression profile in the two muscle fibers of T. rubripes, we generated 54 million and 44 million clean reads from the fast twitch muscle and slow twitch muscle, respectively, using RNA-Seq and identified a total of 580 fast-muscle-specific genes, 1533 slow-muscle-specific genes and 11,806 genes expressed by both muscles. Comparative transcriptome analysis of fast and slow twitch muscles allowed the identification of 1508 differentially expressed genes, of which 34 myosin and 30 ubiquitin family genes were determined. These differentially expressed genes (DEGs) were also analyzed by Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. In addition, alternative splicing analysis was also performed. The generation of larger-scale transcriptomic data presented in this work would enrich the genetic resources of Takifugu rubripes, which could be valuable to comparative studies of muscles. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Human muscle spindle sensitivity reflects the balance of activity between antagonistic muscles.

    Science.gov (United States)

    Dimitriou, Michael

    2014-10-08

    Muscle spindles are commonly considered as stretch receptors encoding movement, but the functional consequence of their efferent control has remained unclear. The "α-γ coactivation" hypothesis states that activity in a muscle is positively related to the output of its spindle afferents. However, in addition to the above, possible reciprocal inhibition of spindle controllers entails a negative relationship between contractile activity in one muscle and spindle afferent output from its antagonist. By recording spindle afferent responses from alert humans using microneurography, I show that spindle output does reflect antagonistic muscle balance. Specifically, regardless of identical kinematic profiles across active finger movements, stretch of the loaded antagonist muscle (i.e., extensor) was accompanied by increased afferent firing rates from this muscle compared with the baseline case of no constant external load. In contrast, spindle firing rates from the stretching antagonist were lowest when the agonist muscle powering movement (i.e., flexor) acted against an additional resistive load. Stepwise regressions confirmed that instantaneous velocity, extensor, and flexor muscle activity had a significant effect on spindle afferent responses, with flexor activity having a negative effect. Therefore, the results indicate that, as consequence of their efferent control, spindle sensitivity (gain) to muscle stretch reflects the balance of activity between antagonistic muscles rather than only the activity of the spindle-bearing muscle. Copyright © 2014 the authors 0270-6474/14/3413644-12$15.00/0.

  16. Action of Obestatin in Skeletal Muscle Repair: Stem Cell Expansion, Muscle Growth, and Microenvironment Remodeling

    Science.gov (United States)

    Gurriarán-Rodríguez, Uxía; Santos-Zas, Icía; González-Sánchez, Jessica; Beiroa, Daniel; Moresi, Viviana; Mosteiro, Carlos S; Lin, Wei; Viñuela, Juan E; Señarís, José; García-Caballero, Tomás; Casanueva, Felipe F; Nogueiras, Rubén; Gallego, Rosalía; Renaud, Jean-Marc; Adamo, Sergio; Pazos, Yolanda; Camiña, Jesús P

    2015-01-01

    The development of therapeutic strategies for skeletal muscle diseases, such as physical injuries and myopathies, depends on the knowledge of regulatory signals that control the myogenic process. The obestatin/GPR39 system operates as an autocrine signal in the regulation of skeletal myogenesis. Using a mouse model of skeletal muscle regeneration after injury and several cellular strategies, we explored the potential use of obestatin as a therapeutic agent for the treatment of trauma-induced muscle injuries. Our results evidenced that the overexpression of the preproghrelin, and thus obestatin, and GPR39 in skeletal muscle increased regeneration after muscle injury. More importantly, the intramuscular injection of obestatin significantly enhanced muscle regeneration by simulating satellite stem cell expansion as well as myofiber hypertrophy through a kinase hierarchy. Added to the myogenic action, the obestatin administration resulted in an increased expression of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR2) and the consequent microvascularization, with no effect on collagen deposition in skeletal muscle. Furthermore, the potential inhibition of myostatin during obestatin treatment might contribute to its myogenic action improving muscle growth and regeneration. Overall, our data demonstrate successful improvement of muscle regeneration, indicating obestatin is a potential therapeutic agent for skeletal muscle injury and would benefit other myopathies related to muscle regeneration. PMID:25762009

  17. Needle muscle biopsy: technique validation and histological and histochemical methods for evaluating canine skeletal muscles

    Directory of Open Access Journals (Sweden)

    Sérgio de Almeida Braga

    2017-05-01

    Full Text Available This study evaluated the needle muscle biopsy technique using a 6G Bergström percutaneous needle combined with histological and histochemical methods to analyze the skeletal muscle of dogs. There are few studies about canine skeletal muscles and a lack of reports in the literature about tissue collection and analysis for canine species. Evaluation of 32 German Shepherd samples collected from the gluteus medius, at a depth of 3 cm, was performed. The choice of gluteus medius and the 3-cm depth provided good quantity fragments with sufficient sizes (3–5 mm, which permitted optimal visualization of muscle fibers. Myosin ATPase, at pH 9.4, 4.6, and 4.3, and SDH reactions revealed that all muscle samples analyzed had fibers in the classic mosaic arrangement, enabling counting and typification. The mean percentages of fibers were 29.95% for type I and 70.05% for type II. On the basis of these results, we concluded that the percutaneous needle biopsy technique for canine skeletal muscles is a safe and easy procedure that obtains fragments of proper sizes, thereby enabling the study of muscle fibers. Standardization of the muscle of choice and the depth of muscle sample collection significantly contributed to this success. This is an important method to evaluate muscle fiber types of dogs and diagnose important diseases affecting the skeletal muscles.

  18. Changes in Predicted Muscle Coordination with Subject-Specific Muscle Parameters for Individuals after Stroke

    Directory of Open Access Journals (Sweden)

    Brian A. Knarr

    2014-01-01

    Full Text Available Muscle weakness is commonly seen in individuals after stroke, characterized by lower forces during a maximal volitional contraction. Accurate quantification of muscle weakness is paramount when evaluating individual performance and response to after stroke rehabilitation. The objective of this study was to examine the effect of subject-specific muscle force and activation deficits on predicted muscle coordination when using musculoskeletal models for individuals after stroke. Maximum force generating ability and central activation ratio of the paretic plantar flexors, dorsiflexors, and quadriceps muscle groups were obtained using burst superimposition for four individuals after stroke with a range of walking speeds. Two models were created per subject: one with generic and one with subject-specific activation and maximum isometric force parameters. The inclusion of subject-specific muscle data resulted in changes in the model-predicted muscle forces and activations which agree with previously reported compensation patterns and match more closely the timing of electromyography for the plantar flexor and hamstring muscles. This was the first study to create musculoskeletal simulations of individuals after stroke with subject-specific muscle force and activation data. The results of this study suggest that subject-specific muscle force and activation data enhance the ability of musculoskeletal simulations to accurately predict muscle coordination in individuals after stroke.

  19. Acute effects of static stretching on muscle-tendon mechanics of quadriceps and plantar flexor muscles.

    Science.gov (United States)

    Bouvier, Tom; Opplert, Jules; Cometti, Carole; Babault, Nicolas

    2017-07-01

    This study aimed to determine the acute effects of static stretching on stiffness indexes of two muscle groups with a contrasting difference in muscle-tendon proportion. Eleven active males were tested on an isokinetic dynamometer during four sessions randomly presented. Two sessions were dedicated to quadriceps and the two others to triceps surae muscles. Before and immediately after the stretching procedure (5 × 30 s), gastrocnemius medialis and rectus femoris fascicle length and myotendinous junction elongation were determined using ultrasonography. Passive and maximal voluntary torques were measured. Fascicle and myotendinous junction stiffness indexes were calculated. After stretching, maximal voluntary torque similarly decreased for both muscle groups. Passive torque significantly decreased on triceps surae and remained unchanged on quadriceps muscles. Fascicle length increased similarly for both muscles. However, myotendinous junction elongation remained unchanged for gastrocnemius medialis and increased significantly for rectus femoris muscle. Fascicle stiffness index significantly decreased on medial gastrocnemius and remained unchanged on rectus femoris muscle. In contrast, myotendinous junction stiffness index similarly decreased on both muscles. Depending on the muscle considered, the present results revealed different acute stretching effects. This muscle dependency appeared to affect primarily fascicle stiffness index rather than the myotendinous junction.

  20. Regulation of skeletal muscle oxidative capacity and muscle mass by SIRT3.

    Directory of Open Access Journals (Sweden)

    Ligen Lin

    Full Text Available We have previously reported that the expression of mitochondrial deacetylase SIRT3 is high in the slow oxidative muscle and that the expression of muscle SIRT3 level is increased by dietary restriction or exercise training. To explore the function of SIRT3 in skeletal muscle, we report here the establishment of a transgenic mouse model with muscle-specific expression of the murine SIRT3 short isoform (SIRT3M3. Calorimetry study revealed that the transgenic mice had increased energy expenditure and lower respiratory exchange rate (RER, indicating a shift towards lipid oxidation for fuel usage, compared to control mice. The transgenic mice exhibited better exercise performance on treadmills, running 45% further than control animals. Moreover, the transgenic mice displayed higher proportion of slow oxidative muscle fibers, with increased muscle AMPK activation and PPARδ expression, both of which are known regulators promoting type I muscle fiber specification. Surprisingly, transgenic expression of SIRT3M3 reduced muscle mass up to 30%, likely through an up-regulation of FOXO1 transcription factor and its downstream atrophy gene MuRF-1. In summary, these results suggest that SIRT3 regulates the formation of oxidative muscle fiber, improves muscle metabolic function, and reduces muscle mass, changes that mimic the effects of caloric restriction.

  1. Muscle fiber population and biochemical properties of whole body muscles in Thoroughbred horses.

    Science.gov (United States)

    Kawai, Minako; Minami, Yoshio; Sayama, Yukiko; Kuwano, Atsutoshi; Hiraga, Atsushi; Miyata, Hirofumi

    2009-10-01

    We examine the muscle fiber population and metabolic properties of skeletal muscles from the whole body in Thoroughbred horses. Postmortem samples were taken from 46 sites in six Thoroughbred horses aged between 3 and 6 years. Fiber type population was determined on muscle fibers stained with monoclonal antibody to each myosin heavy chain isoform and metabolic enzyme activities were determined spectrophotometrically. Histochemical analysis demonstrated that most of the muscles had a high percentage of Type IIa fibers. In terms of the muscle characteristic in several parts of the horse body, the forelimb muscles had a higher percentage of Type IIa fiber and a significantly lower percentage of Type IIx fiber than the hindlimb muscles. The muscle fiber type populations in the thoracic and trunk portion were similar to those in the hindlimb portion. Biochemical analysis indicated high succinate dehydrogenase activity in respiratory-related muscle and high phosphofructokinase activity in hindlimbs. We suggested that the higher percentage of Type IIa fibers in Thoroughbred racehorses is attributed to training effects. To consider further the physiological significance of each part of the body, data for the recruitment pattern of each muscle fiber type during exercise are needed. The muscle fiber properties in this study combined with the recruitment data would provide fundamental information for physiological and pathological studies in Thoroughbred horses.

  2. Mediators on human airway smooth muscle.

    Science.gov (United States)

    Armour, C; Johnson, P; Anticevich, S; Ammit, A; McKay, K; Hughes, M; Black, J

    1997-01-01

    1. Bronchial hyperresponsiveness in asthma may be due to several abnormalities, but must include alterations in the airway smooth muscle responsiveness and/or volume. 2. Increased responsiveness of airway smooth muscle in vitro can be induced by certain inflammatory cell products and by induction of sensitization (atopy). 3. Increased airway smooth muscle growth can also be induced by inflammatory cell products and atopic serum. 4. Mast cell numbers are increased in the airways of asthmatics and, in our studies, in airway smooth muscle that is sensitized and hyperresponsive. 5. We propose that there is a relationship between mast cells and airway smooth muscle cells which, once an allergic process has been initiated, results in the development of critical features in the lungs in asthma.

  3. Intraurethral Injection of Autologous Minced Skeletal Muscle

    DEFF Research Database (Denmark)

    Gräs, Søren; Klarskov, Niels; Lose, Gunnar

    2014-01-01

    PURPOSE: Intraurethral injection of in vitro expanded autologous skeletal muscle derived cells is a new regenerative therapy for stress urinary incontinence. We examined the efficacy and safety of a simpler alternative strategy using freshly harvested, minced autologous skeletal muscle tissue...... noted. CONCLUSIONS: Intraurethral injection of minced autologous muscle tissue is a simple surgical procedure that appears safe and moderately effective in women with uncomplicated stress urinary incontinence. It compares well to a more complicated regenerative strategy using in vitro expanded muscle...... with its inherent content of regenerative cells. MATERIALS AND METHODS: A total of 20 and 15 women with uncomplicated and complicated stress urinary incontinence, respectively, received intraurethral injections of minced autologous skeletal muscle tissue and were followed for 1 year. Efficacy was assessed...

  4. ACUTE EXERCISE-INDUCED MUSCLE INJURY

    Directory of Open Access Journals (Sweden)

    Andrew J McKune

    2012-03-01

    Full Text Available While much research has recently been focussing on the chronic effects of overtraining, the acute damaging effects of individual eccentric exercise bouts on muscle remain of interest and underlie long-term training effects. Systemic markers of muscle damage are limited in terms of sensitivity and reliability. A clearer insight into the extent of the damage and mechanisms involved are being obtained from ultrastructural, functional and molecular examination of the muscle. There are currently indications that while the initial muscle damage may appear to have negative consequences in the short term, intense eccentric exercise appears to initiate a remodelling process and promote favourable adaptation of muscle following training, which has applications for promoting health, rehabilitation and sports performance.

  5. Exercise in muscle glycogen storage diseases

    DEFF Research Database (Denmark)

    Preisler, Nicolai Rasmus; Haller, Ronald G; Vissing, John

    2015-01-01

    oxidation. Such changes may be detrimental for persons with GSD from a metabolic perspective. However, exercise may alter skeletal muscle substrate metabolism in ways that are beneficial for patients with GSD, such as improving exercise tolerance and increasing fatty acid oxidation. In addition, a regular......Glycogen storage diseases (GSD) are inborn errors of glycogen or glucose metabolism. In the GSDs that affect muscle, the consequence of a block in skeletal muscle glycogen breakdown or glucose use, is an impairment of muscular performance and exercise intolerance, owing to 1) an increase...... in glycogen storage that disrupts contractile function and/or 2) a reduced substrate turnover below the block, which inhibits skeletal muscle ATP production. Immobility is associated with metabolic alterations in muscle leading to an increased dependence on glycogen use and a reduced capacity for fatty acid...

  6. Lactate metabolism: bioenergetics and muscle fatigue review

    Directory of Open Access Journals (Sweden)

    Romulo Cássio de Moraes Bertuzzi

    2009-04-01

    Full Text Available The purpose of this study was to present the main events regarding the muscle lactate metabolism to aid the understanding about utilization of the blood lactate concentrations (BLC on the estimative of lactic anaerobic metabolism and its likely relationship to the acute muscle fatigue. Traditionally, the increase of BLC was associated to the insufficient mitochondrial O2 supply. However, recent studies showed that increase of BLC can be due the action of another agent such as epinephrine and inorganic phosphate. In the same way, the relationship between BLC and acute muscle fatigue has been supported by increase in cellular acidosis. Nevertheless, recent studies have shown that cellular acidosis can restore the force in isolated and electrically stimulated muscle fibers. These findings suggest that utilization of the BLC on the estimative of lactic anaerobic metabolism should be used with caution and the relationship between BLC and acute muscle fatigue can only be a casual phenomenon.

  7. Increased muscle glucose uptake during contractions

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Galbo, Henrik; Richter, Erik

    1984-01-01

    We reinvestigated the prevailing concept that muscle contractions only elicit increased muscle glucose uptake in the presence of a so-called "permissive" concentration of insulin (Berger et al., Biochem. J. 146: 231-238, 1975; Vranic and Berger, Diabetes 28: 147-163, 1979). Hindquarters from rats...... in severe ketoacidosis were perfused with a perfusate containing insulin antiserum. After 60 min perfusion, electrical stimulation increased glucose uptake of the contracting muscles fivefold. Also, subsequent contractions increased glucose uptake in hindquarters from nondiabetic rats perfused for 1.5 h......-methylglucose uptake increased during contractions and glucose uptake was negative at rest and zero during contractions. An increase in muscle transport and uptake of glucose during contractions does not require the presence of insulin. Furthermore, glucose transport in contracting muscle may only increase if glycogen...

  8. A hybrid static optimisation method to estimate muscle forces during muscle co-activation.

    Science.gov (United States)

    Son, Jongsang; Hwang, Sungjae; Kim, Youngho

    2012-01-01

    The general static optimisation (GSO) process is one of various muscle force estimation methods due to its low computational requirements. However, it can show biased muscle force estimation under muscle co-contraction. In the present study, we introduced a novel hybrid static optimisation (HSO) method to estimate reasonable muscle forces during muscle co-activation movements using more specific equality constraints, i.e. agonist and antagonist muscle moments predicted from a new correlation coefficient approach. The new method was evaluated for heel-rise movements. We found that the proposed method improved the potential of antagonist muscle force estimation in comparison to the GSO solutions. The proposed HSO method could be applied in biomechanics and rehabilitation, for example.

  9. Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

    Science.gov (United States)

    Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

    2017-07-22

    Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Muscle activation during selected strength exercises in women with chronic neck muscle pain

    DEFF Research Database (Denmark)

    Andersen, Lars L; Kjaer, Michael; Andersen, Christoffer H

    2008-01-01

    selected strengthening exercises in women undergoing rehabilitation for chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia). SUBJECTS: The subjects were 12 female workers (age=30-60 years) with a clinical diagnosis of trapezius myalgia and a mean baseline pain intensity of 5......BACKGROUND AND PURPOSE: Muscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this study was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) during...... muscle pain. Several of the strength exercises had high activation of neck and shoulder muscles in women with chronic neck pain. These exercises can be used equally in the attempt to achieve a beneficial treatment effect on chronic neck muscle pain....

  11. Single Muscle Fiber Proteomics Reveals Fiber-Type-Specific Features of Human Muscle Aging

    Directory of Open Access Journals (Sweden)

    Marta Murgia

    2017-06-01

    Full Text Available Skeletal muscle is a key tissue in human aging, which affects different muscle fiber types unequally. We developed a highly sensitive single muscle fiber proteomics workflow to study human aging and show that the senescence of slow and fast muscle fibers is characterized by diverging metabolic and protein quality control adaptations. Whereas mitochondrial content declines with aging in both fiber types, glycolysis and glycogen metabolism are upregulated in slow but downregulated in fast muscle fibers. Aging mitochondria decrease expression of the redox enzyme monoamine oxidase A. Slow fibers upregulate a subset of actin and myosin chaperones, whereas an opposite change happens in fast fibers. These changes in metabolism and sarcomere quality control may be related to the ability of slow, but not fast, muscle fibers to maintain their mass during aging. We conclude that single muscle fiber analysis by proteomics can elucidate pathophysiology in a sub-type-specific manner.

  12. The expression of HSP in human skeletal muscle. Effects of muscle fiber phenotype and training background

    DEFF Research Database (Denmark)

    Folkesson, Mattias; Mackey, Abigail L; Langberg, Henning

    2013-01-01

    AIM: Exercise-induced adaptations of skeletal muscle are related to training mode and can be muscle fibre type specific. This study aimed to investigate heat shock protein expression in type I and type II muscle fibres in resting skeletal muscle of subjects with different training backgrounds...... HSPs in human skeletal muscle is influenced by muscle fibre phenotype. The fibre type specific expression of HSP70 is influenced by resistance and endurance training whereas those of αB-crystallin and HSP27 are influenced only by endurance training suggesting the existence of a training......-modality specific action on the adaptive processes including heat shock proteins in human skeletal muscle. This article is protected by copyright. All rights reserved....

  13. Rupture of Plantaris Muscle - A Mimic: MRI Findings

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    T N Gopinath

    2012-01-01

    Full Text Available Calf muscle trauma commonly involves the gastrocnemius and soleus muscles. Plantaris muscle is a vestigial muscle coursing through the calf. Similar clinical features may be seen with injury to the plantaris muscle. It can also mimic other conditions like deep vein thrombosis, rupture of Baker′s cyst, and tumors. MRI is helpful in identifying and characterizing it. We report two cases of ruptured plantaris muscle seen on MRI.

  14. The sag response in human muscle contraction.

    Science.gov (United States)

    Smith, Ian C; Ali, Jahaan; Power, Geoffrey A; Herzog, Walter

    2018-03-08

    We examined how muscle length and time between stimuli (inter-pulse interval, IPI) influence declines in force (sag) seen during unfused tetani in the human adductor pollicis muscle. A series of 16-pulse contractions were evoked with IPIs between 1 × and 5 × the twitch time to peak tension (TPT) at large (long muscle length) and small (short muscle length) thumb adduction angles. Unfused tetani were mathematically deconstructed into a series of overlapping twitch contractions to examine why sag exhibits length- and IPI-dependencies. Across all IPIs tested, sag was 62% greater at short than long muscle length, and sag increased as IPI was increased at both muscle lengths. Force attributable to the second stimulus increased as IPI was decreased. Twitch force declined from maximal values across all IPI tested, with the greatest reductions seen at short muscle length and long IPI. At IPI below 2 × TPT, the twitch with highest force occurred earlier than the peak force of the corresponding unfused tetani. Contraction-induced declines in twitch duration (TPT + half relaxation time) were only observed at IPI longer than 1.75 × TPT, and were unaffected by muscle length. Sag is an intrinsic feature of healthy human adductor pollicis muscle. The length-dependence of sag is related to greater diminution of twitch force at short relative to long muscle length. The dependence of sag on IPI is related to IPI-dependent changes in twitch duration and twitch force, and the timing of peak twitch force relative to the peak force of the associated unfused tetanus.

  15. Morphological Study Of Palmaris Longus Muscle

    Directory of Open Access Journals (Sweden)

    Humberto Ferreira Arquez

    2017-07-01

    Full Text Available Background: The palmaris longus is one of the most variable muscle in the human body, this variations are important not only for the anatomist but also radiologist, orthopaedic, plastic surgeons, clinicians, therapists. In view of this significance is performed this study with the purpose to determine the morphological variations of palmaris longus muscle. Methods and Findings: A total of 17 cadavers with different age groups were used for this study. The upper limbs region (34 sides were dissected carefully and photographed in the Morphology Laboratory at the University of Pamplona. Of the 34 limbs studied, 30 showed normal morphology of the Palmaris longus muscle (PL (88,2%; PL was absent in 3 subjects (8,85% of all examined forearm. Unilateral absence was found in 1 male subject (2,95% of all examined forearm; bilateral agenesis was found in 2 female subjects (5,9% of all examined forearm. Duplicated PL muscle was found in 1 male subject (2,95 % of all examined forearm. The palmaris longus muscle was innervated by branches of the median nerve .The accessory palmaris longus muscle was supplied by the deep branch of the ulnar nerve.  Palmaris longus muscle is a muscle located in the superficial layer of the anterior compartment of the forearm. It has a small belly arising from the medial epicondyle of the humerus, and its long thin tendon inserts into the palmar aponeurosis in the hand, the muscle has importance in medical clinic, surgery, radiological analysis, in studies about high-performance athletes, in genetics and anthropologic studies. Conclusions: The anatomical variations of the palmaris longus muscle must be documented of their clinical significance and their potential use in orthopaedic and reconstructive surgery.

  16. Mechanisms regulating skeletal muscle growth and atrophy.

    Science.gov (United States)

    Schiaffino, Stefano; Dyar, Kenneth A; Ciciliot, Stefano; Blaauw, Bert; Sandri, Marco

    2013-09-01

    Skeletal muscle mass increases during postnatal development through a process of hypertrophy, i.e. enlargement of individual muscle fibers, and a similar process may be induced in adult skeletal muscle in response to contractile activity, such as strength exercise, and specific hormones, such as androgens and β-adrenergic agonists. Muscle hypertrophy occurs when the overall rates of protein synthesis exceed the rates of protein degradation. Two major signaling pathways control protein synthesis, the IGF1-Akt-mTOR pathway, acting as a positive regulator, and the myostatin-Smad2/3 pathway, acting as a negative regulator, and additional pathways have recently been identified. Proliferation and fusion of satellite cells, leading to an increase in the number of myonuclei, may also contribute to muscle growth during early but not late stages of postnatal development and in some forms of muscle hypertrophy in the adult. Muscle atrophy occurs when protein degradation rates exceed protein synthesis, and may be induced in adult skeletal muscle in a variety of conditions, including starvation, denervation, cancer cachexia, heart failure and aging. Two major protein degradation pathways, the proteasomal and the autophagic-lysosomal pathways, are activated during muscle atrophy and variably contribute to the loss of muscle mass. These pathways involve a variety of atrophy-related genes or atrogenes, which are controlled by specific transcription factors, such as FoxO3, which is negatively regulated by Akt, and NF-κB, which is activated by inflammatory cytokines. © 2013 The Authors Journal compilation © 2013 FEBS.

  17. Respiratory muscle training increases respiratory muscle strength and reduces respiratory complications after stroke: a systematic review

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    Kênia KP Menezes

    2016-07-01

    Full Text Available Question: After stroke, does respiratory muscle training increase respiratory muscle strength and/or endurance? Are any benefits carried over to activity and/or participation? Does it reduce respiratory complications? Design: Systematic review of randomised or quasi-randomised trials. Participants: Adults with respiratory muscle weakness following stroke. Intervention: Respiratory muscle training aimed at increasing inspiratory and/or expiratory muscle strength. Outcome measures: Five outcomes were of interest: respiratory muscle strength, respiratory muscle endurance, activity, participation and respiratory complications. Results: Five trials involving 263 participants were included. The mean PEDro score was 6.4 (range 3 to 8, showing moderate methodological quality. Random-effects meta-analyses showed that respiratory muscle training increased maximal inspiratory pressure by 7 cmH2O (95% CI 1 to 14 and maximal expiratory pressure by 13 cmH2O (95% CI 1 to 25; it also decreased the risk of respiratory complications (RR 0.38, 95% CI 0.15 to 0.96 compared with no/sham respiratory intervention. Whether these effects carry over to activity and participation remains uncertain. Conclusion: This systematic review provided evidence that respiratory muscle training is effective after stroke. Meta-analyses based on five trials indicated that 30 minutes of respiratory muscle training, five times per week, for 5 weeks can be expected to increase respiratory muscle strength in very weak individuals after stroke. In addition, respiratory muscle training is expected to reduce the risk of respiratory complications after stroke. Further studies are warranted to investigate whether the benefits are carried over to activity and participation. Registration: PROSPERO (CRD42015020683. [Menezes KKP, Nascimento LR, Ada L, Polese JC, Avelino PR, Teixeira-Salmela LF (2016 Respiratory muscle training increases respiratory muscle strength and reduces respiratory

  18. Changes in muscle fiber contractility and extracellular matrix production during skeletal muscle hypertrophy.

    Science.gov (United States)

    Mendias, Christopher L; Schwartz, Andrew J; Grekin, Jeremy A; Gumucio, Jonathan P; Sugg, Kristoffer B

    2017-03-01

    Skeletal muscle can adapt to increased mechanical loads by undergoing hypertrophy. Transient reductions in whole muscle force production have been reported during the onset of hypertrophy, but contractile changes in individual muscle fibers have not been previously studied. Additionally, the extracellular matrix (ECM) stores and transmits forces from muscle fibers to tendons and bones, and determining how the ECM changes during hypertrophy is important in understanding the adaptation of muscle tissue to mechanical loading. Using the synergist ablation model, we sought to measure changes in muscle fiber contractility, collagen content, and cross-linking, and in the expression of several genes and activation of signaling proteins that regulate critical components of myogenesis and ECM synthesis and remodeling during muscle hypertrophy. Tissues were harvested 3, 7, and 28 days after induction of hypertrophy, and nonoverloaded rats served as controls. Muscle fiber specific force (sF o ), which is the maximum isometric force normalized to cross-sectional area, was reduced 3 and 7 days after the onset of mechanical overload, but returned to control levels by 28 days. Collagen abundance displayed a similar pattern of change. Nearly a quarter of the transcriptome changed over the course of overload, as well as the activation of signaling pathways related to hypertrophy and atrophy. Overall, this study provides insight into fundamental mechanisms of muscle and ECM growth, and indicates that although muscle fibers appear to have completed remodeling and regeneration 1 mo after synergist ablation, the ECM continues to be actively remodeling at this time point. NEW & NOTEWORTHY This study utilized a rat synergist ablation model to integrate changes in single muscle fiber contractility, extracellular matrix composition, activation of important signaling pathways in muscle adaption, and corresponding changes in the muscle transcriptome to provide novel insight into the basic

  19. Muscle metaboreflex-induced vasoconstriction in the ischemic active muscle is exaggerated in heart failure.

    Science.gov (United States)

    Kaur, Jasdeep; Senador, Danielle; Krishnan, Abhinav C; Hanna, Hanna W; Alvarez, Alberto; Machado, Tiago M; O'Leary, Donal S

    2018-01-01

    When oxygen delivery to active muscle is insufficient to meet the metabolic demand during exercise, metabolites accumulate and stimulate skeletal muscle afferents, inducing a reflex increase in blood pressure, termed the muscle metaboreflex. In healthy individuals, muscle metaboreflex activation (MMA) during submaximal exercise increases arterial pressure primarily via an increase in cardiac output (CO), as little peripheral vasoconstriction occurs. This increase in CO partially restores blood flow to ischemic muscle. However, we recently demonstrated that MMA induces sympathetic vasoconstriction in ischemic active muscle, limiting the ability of the metaboreflex to restore blood flow. In heart failure (HF), increases in CO are limited, and metaboreflex-induced pressor responses occur predominantly via peripheral vasoconstriction. In the present study, we tested the hypothesis that vasoconstriction of ischemic active muscle is exaggerated in HF. Changes in hindlimb vascular resistance [femoral arterial pressure ÷ hindlimb blood flow (HLBF)] were observed during MMA (via graded reductions in HLBF) during mild exercise with and without α 1 -adrenergic blockade (prazosin, 50 µg/kg) before and after induction of HF. In normal animals, initial HLBF reductions caused metabolic vasodilation, while reductions below the metaboreflex threshold elicited reflex vasoconstriction, in ischemic active skeletal muscle, which was abolished after α 1 -adrenergic blockade. Metaboreflex-induced vasoconstriction of ischemic active muscle was exaggerated after induction of HF. This heightened vasoconstriction impairs the ability of the metaboreflex to restore blood flow to ischemic muscle in HF and may contribute to the exercise intolerance observed in these patients. We conclude that sympathetically mediated vasoconstriction of ischemic active muscle during MMA is exaggerated in HF. NEW & NOTEWORTHY We found that muscle metaboreflex-induced vasoconstriction of the ischemic active

  20. Muscle size explains low passive skeletal muscle force in heart failure patients

    Directory of Open Access Journals (Sweden)

    Fausto Antonio Panizzolo

    2016-09-01

    Full Text Available Background Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF. However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function. Therefore, the aim of this study was to investigate passive force in a single muscle for which non-invasive measures of muscle size and estimates of fiber force are possible, the soleus (SOL, both in CHF patients and age- and physical activity-matched control participants. Methods Passive SOL muscle force and size were obtained by means of a novel approach combining experimental data (dynamometry, electromyography, ultrasound imaging with a musculoskeletal model. Results We found reduced passive SOL forces (∼30% (at the same relative levels of muscle stretch in CHF vs. healthy individuals. This difference was eliminated when force was normalized by physiological cross sectional area, indicating that reduced force output may be most strongly associated with muscle size. Nevertheless, passive force was significantly higher in CHF at a given absolute muscle length (non length-normalized and likely explained by the shorter muscle slack lengths and optimal muscle lengths measured in CHF compared to the control participants. This later factor may lead to altered performance of the SOL in functional tasks such gait. Discussion These findings suggest introducing exercise rehabilitation targeting muscle hypertrophy and, specifically for the calf muscles, exercise that promotes muscle lengthening.

  1. Muscle satellite cells are functionally impaired in myasthenia gravis: consequences on muscle regeneration.

    Science.gov (United States)

    Attia, Mohamed; Maurer, Marie; Robinet, Marieke; Le Grand, Fabien; Fadel, Elie; Le Panse, Rozen; Butler-Browne, Gillian; Berrih-Aknin, Sonia

    2017-12-01

    Myasthenia gravis (MG) is a neuromuscular disease caused in most cases by anti-acetyl-choline receptor (AChR) autoantibodies that impair neuromuscular signal transmission and affect skeletal muscle homeostasis. Myogenesis is carried out by muscle stem cells called satellite cells (SCs). However, myogenesis in MG had never been explored. The aim of this study was to characterise the functional properties of myasthenic SCs as well as their abilities in muscle regeneration. SCs were isolated from muscle biopsies of MG patients and age-matched controls. We first showed that the number of Pax7+ SCs was increased in muscle sections from MG and its experimental autoimmune myasthenia gravis (EAMG) mouse model. Myoblasts isolated from MG muscles proliferate and differentiate more actively than myoblasts from control muscles. MyoD and MyoG were expressed at a higher level in MG myoblasts as well as in MG muscle biopsies compared to controls. We found that treatment of control myoblasts with MG sera or monoclonal anti-AChR antibodies increased the differentiation and MyoG mRNA expression compared to control sera. To investigate the functional ability of SCs from MG muscle to regenerate, we induced muscle regeneration using acute cardiotoxin injury in the EAMG mouse model. We observed a delay in maturation evidenced by a decrease in fibre size and MyoG mRNA expression as well as an increase in fibre number and embryonic myosin heavy-chain mRNA expression. These findings demonstrate for the first time the altered function of SCs from MG compared to control muscles. These alterations could be due to the anti-AChR antibodies via the modulation of myogenic markers resulting in muscle regeneration impairment. In conclusion, the autoimmune attack in MG appears to have unsuspected pathogenic effects on SCs and muscle regeneration, with potential consequences on myogenic signalling pathways, and subsequently on clinical outcome, especially in the case of muscle stress.

  2. Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Pearson, William G.; Hindson, David F.; Langmore, Susan E.; Zumwalt, Ann C.

    2013-01-01

    Purpose: Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. Methods and Materials: mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Results: Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Conclusions

  3. Triglyceride metabolism in exercising muscle.

    Science.gov (United States)

    Watt, Matthew J; Cheng, Yunsheng

    2017-10-01

    Triglycerides are stored within lipid droplets in skeletal muscle and can be hydrolyzed to produce fatty acids for energy production through β-oxidation and oxidative phosphorylation. While there was some controversy regarding the quantitative importance of intramyocellular triglyceride (IMTG) as a metabolic substrate, recent advances in proton magnetic resonance spectroscopy and confocal microscopy support earlier tracer and biopsy studies demonstrating a substantial contribution of IMTG to energy production, particularly during moderate-intensity endurance exercise. This review provides an update on the understanding of IMTG utilization during exercise, with a focus on describing the key regulatory proteins that control IMTG breakdown and how these proteins respond to acute exercise and in the adaptation to exercise training. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. The influence of inspiratory muscle work history and specific inspiratory muscle training upon human limb muscle fatigue

    Science.gov (United States)

    McConnell, Alison K; Lomax, Michelle

    2006-01-01

    The purpose of this study was to assess the influence of the work history of the inspiratory muscles upon the fatigue characteristics of the plantar flexors (PF). We hypothesized that under conditions where the inspiratory muscle metaboreflex has been elicited, PF fatigue would be hastened due to peripheral vasoconstriction. Eight volunteers undertook seven test conditions, two of which followed 4 week of inspiratory muscle training (IMT). The inspiratory metaboreflex was induced by inspiring against a calibrated flow resistor. We measured torque and EMG during isometric PF exercise at 85% of maximal voluntary contraction (MVC) torque. Supramaximal twitches were superimposed upon MVC efforts at 1 min intervals (MVCTI); twitch interpolation assessed the level of central activation. PF was terminated (Tlim) when MVCTI was inspiratory muscle work (6.28 ± 2.24 min; P = 0.009). Resting the inspiratory muscles for 30 min restored the PF Tlim to control. After 4 weeks, IMT, inspiratory muscle work at the same absolute intensity did not influence PF Tlim, but Tlim was significantly shorter at the same relative intensity. The data are the first to provide evidence that the inspiratory muscle metaboreflex accelerates the rate of calf fatigue during PF, and that IMT attenuates this effect. PMID:16973699

  5. Mechanics of Vascular Smooth Muscle.

    Science.gov (United States)

    Ratz, Paul H

    2015-12-15

    Vascular smooth muscle (VSM; see Table 1 for a list of abbreviations) is a heterogeneous biomaterial comprised of cells and extracellular matrix. By surrounding tubes of endothelial cells, VSM forms a regulated network, the vasculature, through which oxygenated blood supplies specialized organs, permitting the development of large multicellular organisms. VSM cells, the engine of the vasculature, house a set of regulated nanomotors that permit rapid stress-development, sustained stress-maintenance and vessel constriction. Viscoelastic materials within, surrounding and attached to VSM cells, comprised largely of polymeric proteins with complex mechanical characteristics, assist the engine with countering loads imposed by the heart pump, and with control of relengthening after constriction. The complexity of this smart material can be reduced by classical mechanical studies combined with circuit modeling using spring and dashpot elements. Evaluation of the mechanical characteristics of VSM requires a more complete understanding of the mechanics and regulation of its biochemical parts, and ultimately, an understanding of how these parts work together to form the machinery of the vascular tree. Current molecular studies provide detailed mechanical data about single polymeric molecules, revealing viscoelasticity and plasticity at the protein domain level, the unique biological slip-catch bond, and a regulated two-step actomyosin power stroke. At the tissue level, new insight into acutely dynamic stress-strain behavior reveals smooth muscle to exhibit adaptive plasticity. At its core, physiology aims to describe the complex interactions of molecular systems, clarifying structure-function relationships and regulation of biological machines. The intent of this review is to provide a comprehensive presentation of one biomachine, VSM. Copyright © 2015 John Wiley & Sons, Inc.

  6. In vivo passive mechanical behaviour of muscle fascicles and tendons in human gastrocnemius muscle-tendon units.

    Science.gov (United States)

    Herbert, Robert D; Clarke, Jillian; Kwah, Li Khim; Diong, Joanna; Martin, Josh; Clarke, Elizabeth C; Bilston, Lynne E; Gandevia, Simon C

    2011-11-01

    Ultrasound imaging was used to measure the length of muscle fascicles in human gastrocnemius muscles while the muscle was passively lengthened and shortened by moving the ankle. In some subjects the muscle belly 'buckled' at short lengths. When the gastrocnemius muscle-tendon unit was passively lengthened from its shortest in vivo length by dorsiflexing the ankle, increases in muscle-tendon length were not initially accompanied by increases in muscle fascicle lengths (fascicle length remained constant), indicating muscle fascicles were slack at short muscle-tendon lengths. The muscle-tendon length at which slack is taken up differs among fascicles: some fascicles begin to lengthen at very short muscle-tendon lengths whereas other fascicles remain slack over a large range of muscle-tendon lengths. This suggests muscle fascicles are progressively 'recruited' and contribute sequentially to muscle-tendon stiffness during passive lengthening of the muscle-tendon unit. Even above their slack lengths muscle fascicles contribute only a small part (tendon length. The contribution of muscle fascicles to muscle-tendon length increases with muscle length. The novelty of this work is that it reveals a previously unrecognised phenomenon (buckling at short lengths), posits a new mechanism of passive mechanical properties of muscle (recruitment of muscle fascicles), and confirms with high-resolution measurements that the passive compliance of human gastrocnemius muscle-tendon units is due largely to the tendon. It would be interesting to investigate if adaptations of passive properties of muscles are associated with changes in the distribution of muscle lengths at which fascicles fall slack.

  7. Muscle-derived Decellularised Extracellular Matrix Improves Functional Recovery in a Rat Latissimus Dorsi Muscle Defect Model

    Science.gov (United States)

    2013-12-01

    in vivo torque production from EMG in mouse muscles injured by eccentric contractions. J Physiol 1999;515(Pt 2):609e19. 27. Gamba PG, Conconi MT, Lo... Muscle -derived decellularised extracellular matrix improves functional recovery in a rat latissimus dorsi muscle defect model Xiaoyu K. Chen a,b...maxillary injuries; Muscle function; Skeletal muscle ; Volumetric muscle loss Summary Purpose: Craniofacial maxillary injuries represent nearly 30% of all

  8. Modelling of pneumatic muscle actuator using Hill's model with different approximations of static characteristics of artificial muscle

    Directory of Open Access Journals (Sweden)

    Piteľ Ján

    2016-01-01

    Full Text Available For modelling and simulation of pneumatic muscle actuators the mathematical dependence of the muscle force on the muscle contraction at different pressures in the muscles is necessary to know. For this purpose the static characteristics of the pneumatic artificial muscle type FESTO MAS-20-250N used in the experiments were approximated. In the paper there are shown some simulation results of the pneumatic muscle actuator dynamics using modified Hill's muscle model, in which four different approximations of static characteristics of artificial muscle were used.

  9. Pneumatic Muscles Actuated Lower-Limb Orthosis Model Verification with Actual Human Muscle Activation Patterns

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    Dzahir M.A.M

    2017-01-01

    Full Text Available A review study was conducted on existing lower-limb orthosis systems for rehabilitation which implemented pneumatic muscle type of actuators with the aim to clarify the current and on-going research in this field. The implementation of pneumatic artificial muscle will play an important role for the development of the advanced robotic system. In this research a derivation model for the antagonistic mono- and bi-articular muscles using pneumatic artificial muscles of a lower limb orthosis will be verified with actual human’s muscle activities models. A healthy and young male 29 years old subject with height 174cm and weight 68kg was used as a test subject. Two mono-articular muscles Vastus Medialis (VM and Vastus Lateralis (VL were selected to verify the mono-articular muscle models and muscle synergy between anterior muscles. Two biarticular muscles Rectus Femoris (RF and Bicep Femoris (BF were selected to verify the bi-articular muscle models and muscle co-contraction between anterior-posterior muscles. The test was carried out on a treadmill with a speed of 4.0 km/h, which approximately around 1.25 m/s for completing one cycle of walking motion. The data was collected for about one minute on a treadmill and 20 complete cycles of walking motion were successfully recorded. For the evaluations, the mathematical model obtained from the derivation and the actual human muscle activation patterns obtained using the surface electromyography (sEMG system were compared and analysed. The results shown that, high correlation values ranging from 0.83 up to 0.93 were obtained in between the derivation model and the actual human muscle’s model for both mono- and biarticular muscles. As a conclusion, based on the verification with the sEMG muscle activities data and its correlation values, the proposed derivation models of the antagonistic mono- and bi-articular muscles were suitable to simulate and controls the pneumatic muscles actuated lower limb

  10. Muscle Fibre Types, Ubiquinone Content and Exercise Capacity in Hypertension and Effort Angina

    DEFF Research Database (Denmark)

    Karlsson, Jan; Diamant, Bertil; Folkers, Karl

    1991-01-01

    Farmakologi, hypertension, IHD, skeletal muscle fibre composition, muscle coenzyme Q10, ischaemic heart disease, effort angina, muscle fibre lesion, muscle ubiquinone......Farmakologi, hypertension, IHD, skeletal muscle fibre composition, muscle coenzyme Q10, ischaemic heart disease, effort angina, muscle fibre lesion, muscle ubiquinone...

  11. Inflammatory response during slow- and fast-twitch muscle regeneration.

    Science.gov (United States)

    Zimowska, Malgorzata; Kasprzycka, Paulina; Bocian, Katarzyna; Delaney, Kamila; Jung, Piotr; Kuchcinska, Kinga; Kaczmarska, Karolina; Gladysz, Daria; Streminska, Wladyslawa; Ciemerych, Maria Anna

    2017-03-01

    Skeletal muscles are characterized by their unique ability to regenerate. Injury of a so-called fast-twitch muscle, extensor digitorum longus (EDL), results in efficient regeneration and reconstruction of the functional tissue. In contrast, slow-twitch muscle (soleus) fails to properly reconstruct and develops fibrosis. This study focuses on soleus and EDL muscle regeneration and associated inflammation. We determined differences in the activity of neutrophils and M1 and M2 macrophages using flow cytometry and differences in the levels of proinflammatory cytokines using Western blotting and immunolocalization at different times after muscle injury. Soleus muscle repair is accompanied by increased and prolonged inflammation, as compared to EDL. The proinflammatory cytokine profile is different in the soleus and ED muscles. Muscle repair efficiency differs by muscle fiber type. The inflammatory response affects the repair efficiency of slow- and fast-twitch muscles. Muscle Nerve 55: 400-409, 2017. © 2016 Wiley Periodicals, Inc.

  12. Muscle damage and its relationship with muscle fatigue during a half-iron triathlon.

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    Juan Del Coso

    Full Text Available BACKGROUND: To investigate the cause/s of muscle fatigue experienced during a half-iron distance triathlon. METHODOLOGY/PRINCIPAL FINDINGS: We recruited 25 trained triathletes (36±7 yr; 75.1±9.8 kg for the study. Before and just after the race, jump height and leg muscle power output were measured during a countermovement jump on a force platform to determine leg muscle fatigue. Body weight, handgrip maximal force and blood and urine samples were also obtained before and after the race. Blood myoglobin and creatine kinase concentrations were determined as markers of muscle damage. RESULTS: Jump height (from 30.3±5.0 to 23.4±6.4 cm; P0.05 but significantly correlated with myoglobin concentration (r = 0.65; P<0.001 and creatine kinase concentration (r = 0.54; P<0.001. CONCLUSIONS/SIGNIFICANCE: During a half-iron distance triathlon, the capacity of leg muscles to produce force was notably diminished while arm muscle force output remained unaffected. Leg muscle fatigue was correlated with blood markers of muscle damage suggesting that muscle breakdown is one of the most relevant sources of muscle fatigue during a triathlon.

  13. Fetal muscle-derived cells can repair dystrophic muscles in mdx mice

    International Nuclear Information System (INIS)

    Auda-Boucher, Gwenola; Rouaud, Thierry; Lafoux, Aude; Levitsky, Dmitri; Huchet-Cadiou, Corinne; Feron, Marie; Guevel, Laetitia; Talon, Sophie; Fontaine-Perus, Josiane; Gardahaut, Marie-France

    2007-01-01

    We have previously reported that CD34 + cells purified from mouse fetal muscles can differentiate into skeletal muscle in vitro and in vivo when injected into muscle tissue of dystrophic mdx mice. In this study, we investigate the ability of such donor cells to restore dystrophin expression, and to improve the functional muscle capacity of the extensor digitorum longus muscle (EDL) of mdx mice. For this purpose green fluorescent-positive fetal GFP + /CD34 + cells or desmin + / - LacZ/CD34 + cells were transplanted into irradiated or non-irradiated mdx EDL muscle. Donor fetal muscle-derived cells predominantly fused with existing fibers. Indeed more than 50% of the myofibers of the host EDL contained donor nuclei delivering dystrophin along 80-90% of the length of their sarcolemma. The presence of significant amounts of dystrophin (about 60-70% of that found in a control wild-type mouse muscle) was confirmed by Western blot analyses. Dystrophin expression also outcompeted that of utrophin, as revealed by a spatial shift in the distribution of utrophin. At 1 month post-transplant, the recipient muscle appeared to have greater resistance to fatigue than control mdx EDL muscle during repeated maximal contractions

  14. Korean mistletoe (Viscum album coloratum) extract regulates gene expression related to muscle atrophy and muscle hypertrophy.

    Science.gov (United States)

    Jeong, Juseong; Park, Choon-Ho; Kim, Inbo; Kim, Young-Ho; Yoon, Jae-Min; Kim, Kwang-Soo; Kim, Jong-Bae

    2017-01-21

    Korean mistletoe (Viscum album coloratum) is a semi-parasitic plant that grows on various trees and has a diverse range of effects on biological functions, being implicated in having anti-tumor, immunostimulatory, anti-diabetic, and anti-obesity properties. Recently, we also reported that Korean mistletoe extract (KME) improves endurance exercise in mice, suggesting its beneficial roles in enhancing the capacity of skeletal muscle. We examined the expression pattern of several genes concerned with muscle physiology in C2C12 myotubes cells to identify whether KME inhibits muscle atrophy or promotes muscle hypertrophy. We also investigated these effects of KME in denervated mice model. Interestingly, KME induced the mRNA expression of SREBP-1c, PGC-1α, and GLUT4, known positive regulators of muscle hypertrophy, in C2C12 cells. On the contrary, KME reduced the expression of Atrogin-1, which is directly involved in the induction of muscle atrophy. In animal models, KME mitigated the decrease of muscle weight in denervated mice. The expression of Atrogin-1 was also diminished in those mice. Moreover, KME enhanced the grip strength and muscle weight in long-term feeding mice. Our results suggest that KME has beneficial effects on muscle atrophy and muscle hypertrophy.

  15. Potential of laryngeal muscle regeneration using induced pluripotent stem cell-derived skeletal muscle cells.

    Science.gov (United States)

    Dirja, Bayu Tirta; Yoshie, Susumu; Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Nakamura, Ryosuke; Otsuki, Koshi; Nomoto, Yukio; Wada, Ikuo; Hazama, Akihiro; Omori, Koichi

    2016-01-01

    Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation.

  16. Exercise-induced muscle glucose uptake in mice with graded, muscle-specific GLUT-4 deletion

    Science.gov (United States)

    Howlett, Kirsten F; Andrikopoulos, Sofianos; Proietto, Joseph; Hargreaves, Mark

    2013-01-01

    To investigate the importance of the glucose transporter GLUT-4 for muscle glucose uptake during exercise, transgenic mice with skeletal muscle GLUT-4 expression approximately 30–60% of normal (CON) and approximately 5–10% of normal (KO) were generated using the Cre/Lox system and compared with wild-type (WT) mice during approximately 40 min of treadmill running (KO: 37.7 ± 1.3 min; WT: 40 min; CON: 40 min, P = 0.18). In WT and CON animals, exercise resulted in an overall increase in muscle glucose uptake. More specifically, glucose uptake was increased in red gastrocnemius of WT mice and in the soleus and red gastrocnemius of CON mice. In contrast, the exercise-induced increase in muscle glucose uptake in all muscles was completely abolished in KO mice. Muscle glucose uptake increased during exercise in both red and white quadriceps of WT mice, while the small increases in CON mice were not statistically significant. In KO mice, there was no change at all in quadriceps muscle glucose uptake. No differences in muscle glycogen use during exercise were observed between any of the groups. However, there was a significant increase in plasma glucose levels after exercise in KO mice. The results of this study demonstrated that a reduction in skeletal muscle GLUT-4 expression to approximately 10% of normal levels completely abolished the exercise-induced increase in muscle glucose uptake. PMID:24303141

  17. Calcium's Role in Mechanotransduction during Muscle Development

    Directory of Open Access Journals (Sweden)

    Tatiana Benavides Damm

    2014-01-01

    Full Text Available Mechanotransduction is a process where cells sense their surroundings and convert the physical forces in their environment into an appropriate response. Calcium plays a crucial role in the translation of such forces to biochemical signals that control various biological processes fundamental in muscle development. The mechanical stimulation of muscle cells may for example result from stretch, electric and magnetic stimulation, shear stress, and altered gravity exposure. The response, mainly involving changes in intracellular calcium concentration then leads to a cascade of events by the activation of downstream signaling pathways. The key calcium-dependent pathways described here include the nuclear factor of activated T cells (NFAT and mitogen-activated protein kinase (MAPK activation. The subsequent effects in cellular homeostasis consist of cytoskeletal remodeling, cell cycle progression, growth, differentiation, and apoptosis, all necessary for healthy muscle development, repair, and regeneration. A deregulation from the normal process due to disuse, trauma, or disease can result in a clinical condition such as muscle atrophy, which entails a significant loss of muscle mass. In order to develop therapies against such diseased states, we need to better understand the relevance of calcium signaling and the downstream responses to mechanical forces in skeletal muscle. The purpose of this review is to discuss in detail how diverse mechanical stimuli cause changes in calcium homeostasis by affecting membrane channels and the intracellular stores, which in turn regulate multiple pathways that impart these effects and control the fate of muscle tissue.

  18. Respiratory muscle function in interstitial lung disease.

    Science.gov (United States)

    Walterspacher, Stephan; Schlager, Daniel; Walker, David J; Müller-Quernheim, Joachim; Windisch, Wolfram; Kabitz, Hans-Joachim

    2013-07-01

    Interstitial lung diseases limit daily activities, impair quality of life and result in (exertional) dyspnoea. This has mainly been attributed to a decline in lung function and impaired gas exchange. However, the contribution of respiratory muscle dysfunction to these limitations remains to be conclusively investigated. Interstitial lung disease patients and matched controls performed body plethysmography, a standardised 6-min walk test, volitional tests (respiratory drive (P0.1), global maximal inspiratory mouth occlusion pressure (PImax), sniff nasal pressure (SnPna) and inspiratory muscle load) and nonvolitional tests on respiratory muscle function and strength (twitch mouth and transdiaphragmatic pressure during bilateral magnetic phrenic nerve stimulation (TwPmo and TwPdi)). 25 patients and 24 controls were included in the study. PImax and SnPna remained unaltered (both p>0.05), whereas P0.1 and the load on the inspiratory muscles were higher (both prespiratory muscle strength remains preserved. Central respiratory drive and the load imposed on the inspiratory muscles are increased. Whether impaired respiratory muscle function impacts morbidity and mortality in interstitial lung disease patients needs to be investigated in future studies.

  19. Satellite cells in human skeletal muscle plasticity

    Directory of Open Access Journals (Sweden)

    Tim eSnijders

    2015-10-01

    Full Text Available Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodelling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodelling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodelling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

  20. GLUT-3 expression in human skeletal muscle

    Science.gov (United States)

    Stuart, C. A.; Wen, G.; Peng, B. H.; Popov, V. L.; Hudnall, S. D.; Campbell, G. A.

    2000-01-01

    Muscle biopsy homogenates contain GLUT-3 mRNA and protein. Before these studies, it was unclear where GLUT-3 was located in muscle tissue. In situ hybridization using a midmolecule probe demonstrated GLUT-3 within all muscle fibers. Fluorescent-tagged antibody reacting with affinity-purified antibody directed at the carboxy-terminus demonstrated GLUT-3 protein in all fibers. Slow-twitch muscle fibers, identified by NADH-tetrazolium reductase staining, possessed more GLUT-3 protein than fast-twitch fibers. Electron microscopy using affinity-purified primary antibody and gold particle-tagged second antibody showed that the majority of GLUT-3 was in association with triads and transverse tubules inside the fiber. Strong GLUT-3 signals were seen in association with the few nerves that traversed muscle sections. Electron microscopic evaluation of human peripheral nerve demonstrated GLUT-3 within the axon, with many of the particles related to mitochondria. GLUT-3 protein was found in myelin but not in Schwann cells. GLUT-1 protein was not present in nerve cells, axons, myelin, or Schwann cells but was seen at the surface of the peripheral nerve in the perineurium. These studies demonstrated that GLUT-3 mRNA and protein are expressed throughout normal human skeletal muscle, but the protein is predominantly found in the triads of slow-twitch muscle fibers.

  1. Gait Variability Related to Muscle Quality and Muscle Power Output in Frail Nonagenarian Older Adults.

    Science.gov (United States)

    Martinikorena, Ion; Martínez-Ramírez, Alicia; Gómez, Marisol; Lecumberri, Pablo; Casas-Herrero, Alvaro; Cadore, Eduardo L; Millor, Nora; Zambom-Ferraresi, Fabricio; Idoate, Fernando; Izquierdo, Mikel

    2016-02-01

    Frailty has become the center of attention of basic, clinical, and demographic research because of its incidence level and the gravity of adverse outcomes with age. Moreover, with advanced age, motor variability increases, particularly in gait. Muscle quality and muscle power seem to be closely associated with performance on functional tests in frail populations. Insight into the relationships among muscle power, muscle quality, and functional capacity could improve the quality of life in this population. In this study, the relationship between the quality of the muscle mass and muscle strength with gait performance in a frail population was examined. Twenty-two institutionalized frail elderly individuals (93.1 ± 3.6) participated in this study. Muscle quality was measured by segmenting areas of high- and low-density fibers as observed in computed tomography images. The assessed functional outcomes were leg strength and power, velocity of gait, and kinematic gait parameters obtained from a tri-axial inertial sensor. Our results showed that a greater number of high-density fibers, specifically those of the quadriceps femoris muscle, were associated with better gait performance in terms of step time variability, regularity, and symmetry. Additionally, gait variability was associated with muscle power. In contrast, no significant relationship was observed between gait velocity and either muscle quality or muscle power. Gait pattern disorders could be explained by a deterioration of the lower limb muscles. It is known that an impaired gait is an important predictor of falls in older populations; thus, the loss of muscle quality and power could underlie the impairments in motor control and balance that lead to falls and adverse outcomes. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  2. Abnormality of Auricular Muscles in Congenital Auricular Deformities.

    Science.gov (United States)

    Yotsuyanagi, Takatoshi; Yamauchi, Makoto; Yamashita, Ken; Sugai, Asuka; Gonda, Ayako; Kitada, Ayaka; Saito, Tamotsu; Urushidate, Satoshi

    2015-07-01

    It has been suggested that there is a close association of abnormality in auricular muscles with various congenital auricular deformities. However, there has been no investigation to determine what muscles are involved and how they affect the deformity. The authors examined abnormalities of auricular muscles for patients with various auricular deformities. The authors examined 77 auricles of 62 patients with congenital auricular deformities, including cryptotia, Stahl's ear, prominent ear, lop ear, and others. The superior and posterior auricular muscles from the extrinsic auricular muscle group and the auricular oblique and transverse muscles from the auricular intrinsic muscle group were investigated. The authors found characteristic features of the abnormality of the muscle for each auricular deformity. In nearly all cases of cryptotia, abnormality was found in the superior auricular, auricular oblique, and auricular transverse muscles. Abnormal insertion was found mainly in the superior auricular muscle and was the main cause of cryptotia. In Stahl's ear, the major abnormality was abnormal insertion of the auricular transverse muscle, which creates an abnormal cartilaginous prominence in the scapha. The abnormality in cases of prominent ear was clearly limited mostly to the auricular transverse muscle and, in some cases, to the posterior auricular muscle. In lop ear, abnormality was mostly found in the auricular transverse muscle, with elongation, and in the superior auricular or auricular oblique muscle in some cases. There is a tendency for a specific muscle abnormality to be found in each deformity. It is important to identify the abnormal muscle and correct the abnormality during the operation.

  3. Evaluation of normal masseter muscles on ultrasonography

    International Nuclear Information System (INIS)

    Hwang, Hyoung Zoo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

    2008-01-01

    To assess the internal echo intensity and morphological variability of masseter muscles on ultrasonography and to establish diagnostic criterion of estimation. Participants consisted of 50 young adults (male 25, female 25) without pathologic conditions and with full natural dentitions. Sonographic examinations were done with real time ultrasound equipment as Logiq 500 (GE Medical Systems, Seoul, Korea) at 3 parts according to lines paralleling with ala-tragus line as reference line. The thickness and area of masseter muscles according to reference line in cross-sectional images were measured at rest and at maximum contraction. The visibility and width of the internal echogenic intensity of the masseter muscles were also assessed and the muscle appearance was classified into 4 types. Data were statistically analyzed by paired t-test and x2-test. 1. When comparing the thickness and area of masseter muscles concerning with gender, there was few significant difference between right and left sides, however, there were significant differences between males and females except for the greatest thickness of left side. 2. The changes of the greatest thickness and the area between rest and maximum contraction showed that the part of the least thickness manifested more increase at maximum contraction. 3. Each part the manifestations of the internal echogenic intensity of the masseter muscles were different depending on the locations. But there was no statistically significance. Changes of muscles thickness with contraction and internal echogenic intensity with locations showed great disparity within the masseter muscles, which will be diagnostic criteria for pathophysiologic and anatomic changes of masseter muscles.

  4. Increased skeletal muscle capillarization enhances insulin sensitivity

    DEFF Research Database (Denmark)

    Åkerström, Thorbjörn; Laub, Lasse; Vedel, Kenneth

    2014-01-01

    that Prazosin was cleared from the blood stream. Whole-body insulin sensitivity was measured in conscious, unrestrained rats by hyperinsulinemic euglycemic clamp. Tissue specific insulin sensitivity was assessed by administration of 2-deoxy-[(3)H]-Glucose during the plateau phase of the clamp. Whole-body...... was enhanced independent of improvements in skeletal muscle insulin signaling to glucose uptake and glycogen synthesis, suggesting that the improvement in insulin-stimulated muscle glucose uptake could be due to improved diffusion conditions for glucose in the muscle. The Prazosin treatment did not affect...

  5. Optimal Control of Isometric Muscle Dynamics

    Directory of Open Access Journals (Sweden)

    Robert Rockenfeller

    2015-03-01

    Full Text Available We use an indirect optimal control approach to calculate the optimal neural stimulation needed to obtain measured isometric muscle forces. The neural stimulation of the nerve system is hereby considered to be a control function (input of the system ’muscle’ that solely determines the muscle force (output. We use a well-established muscle model and experimental data of isometric contractions. The model consists of coupled activation and contraction dynamics described by ordinary differential equations. To validate our results, we perform a comparison with commercial optimal control software.

  6. Medial Elbow Joint Space Increases With Valgus Stress and Decreases When Cued to Perform A Maximal Grip Contraction.

    Science.gov (United States)

    Pexa, Brett S; Ryan, Eric D; Myers, Joseph B

    2018-04-01

    Previous research indicates that the amount of valgus torque placed on the elbow joint during overhead throwing is higher than the medial ulnar collateral ligament (UCL) can tolerate. Wrist and finger flexor muscle activity is hypothesized to make up for this difference, and in vitro studies that simulated activity of upper extremity musculature, specifically the flexor digitorum superficialis and flexor carpi ulnaris, support this hypothesis. To assess the medial elbow joint space at rest, under valgus stress, and under valgus stress with finger and forearm flexor contraction by use of ultrasonography in vivo. Controlled laboratory study. Participants were 22 healthy males with no history of elbow dislocation or UCL injury (age, 21.25 ± 1.58 years; height, 1.80 ± 0.08 m; weight, 79.43 ± 18.50 kg). Medial elbow joint space was measured by use of ultrasonography during 3 separate conditions: at rest (unloaded), under valgus load (loaded), and with a maximal grip contraction under a valgus load (loaded-contracted) in both limbs. Participants lay supine with their arm abducted 90° and elbow flexed 30° with the forearm in full supination. A handgrip dynamometer was placed in the participants' hand to grip against during the contracted condition. Images were reduced in ImageJ to assess medial elbow joint space. A 2-way (condition × limb) repeated-measures analysis of variance and Cohen's d effect sizes were used to assess changes in medial elbow joint space. Post hoc testing was performed with a Bonferroni adjustment to assess changes within limb and condition. The medial elbow joint space was significantly larger in the loaded condition (4.91 ± 1.16 mm) compared with the unloaded condition (4.26 ± 1.23 mm, P space increases under a valgus load and then decreases when a maximal grip contraction is performed. This indicates that wrist and finger flexor muscle contraction may assist in limiting medial elbow joint space, a result similar to findings of previous

  7. Human skeletal muscle fibroblasts stimulate in vitro myogenesis and in vivo muscle regeneration.

    Science.gov (United States)

    Mackey, Abigail L; Magnan, Mélanie; Chazaud, Bénédicte; Kjaer, Michael

    2017-08-01

    Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. The extent of cross-talk between fibroblasts, as the source of matrix protein, and satellite cells in humans is unknown. We studied this in human muscle biopsies and cell-culture studies. We observed a strong stimulation of myogenesis by human fibroblasts in cell culture. In biopsies collected 30 days after a muscle injury protocol, fibroblast number increased to four times control levels, where fibroblasts were found to be preferentially located immediately surrounding regenerating muscle fibres. These novel findings indicate an important role for fibroblasts in supporting the regeneration of muscle fibres, potentially through direct stimulation of satellite cell differentiation and fusion, and contribute to understanding of cell-cell cross-talk during physiological and pathological muscle remodelling. Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. In addition to the indispensable role satellite cells play in muscle regeneration, there is emerging evidence in rodents for a regulatory influence on fibroblast activity. However, the influence of fibroblasts on satellite cells and muscle regeneration in humans is unknown. The purpose of this study was to investigate this in vitro and during in vivo regeneration in humans. Following a muscle injury protocol in young healthy men (n = 7), the number of fibroblasts (TCF7L2+), satellite cells (Pax7+), differentiating myogenic cells (myogenin+) and regenerating fibres (neonatal/embryonic myosin+) was determined from biopsy cross-sections. Fibroblasts and myogenic precursor cells (MPCs) were also isolated from human skeletal muscle (n = 4) and co-cultured using different cell ratios, with the two cell populations either in direct contact with each other or separated by a permeable

  8. The influence of inspiratory muscle work history and specific inspiratory muscle training upon human limb muscle fatigue

    OpenAIRE

    McConnell, AK; Lomax, M

    2006-01-01

    This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright @ 2006 The Authors. The purpose of this study was to assess the influence of the work history of the inspiratory muscles upon the fatigue characteristics of the plantar flexors (PF). We hypothesized that under conditions where the inspiratory muscle metaboreflex has been elicited, PF fatigue would be hastened due to peripheral vasoconstriction. Eight volu...

  9. Fuzzy Control of a Robotic Arm using EMG Signals

    OpenAIRE

    Hidalgo, M.; Tene, G.; Sánchez Terán, Alberto

    2007-01-01

    This paper presents the control design of a robotic arm employing Fuzzy algorithms to interpret electromiographic (EMG) signals from the Flexor Carpi Radialis, Extensor Carpi Radialis and Biceps Brachii muscles. The control and aquisition systems is composed of a microprocessor, analog ?ltering, digital ?ltering and frequency analysis, and ?nally a fuzzy control system. The system has been implemented over a MICROCHIP PIC 16F876 and LabVIEW.

  10. Testosterone enhances C-14 2-deoxyglucose uptake by striated muscle. [sex hormones and muscle

    Science.gov (United States)

    Toop, J.; Max, S. R.

    1982-01-01

    The effect of testosterone propionate (TP) on C-14 2-deoxyglucose (C-14 2DG) uptake was studied in the rat levator ani muscle in vivo using the autoradiographic technique. Following a delay of 1 to 3 h after injecting TP, the rate of C-14 2DG uptake in experimental animals began to increase and continued to increase for at least 20 h. The label, which corresponds to C-14 2-deoxyglucose 6-phosphate, as demonstrated by chromatographic analysis of muscle extracts, was uniformly distributed over the entire muscle and was predominantly in muscle fibers, although nonmuscular elements were also labeled. The 1 to 3 h time lag suggests that the TP effect may be genomic, acting via androgen receptors, rather than directly on muscle membranes. Acceleration of glucose uptake may be an important early event in the anabolic response of the rat levator ani muscle to androgens.

  11. 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.

  12. Baroreflex modulation of muscle sympathetic nerve activity during posthandgrip muscle ischemia in humans

    Science.gov (United States)

    Cui, J.; Wilson, T. E.; Shibasaki, M.; Hodges, N. A.; Crandall, C. G.

    2001-01-01

    To identify whether muscle metaboreceptor stimulation alters baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA, beat-by-beat arterial blood pressure (Finapres), and electrocardiogram were recorded in 11 healthy subjects in the supine position. Subjects performed 2 min of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 2.5 min of posthandgrip muscle ischemia. During muscle ischemia, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative (P baroreflex modulation of MSNA is elevated by muscle metaboreceptor stimulation, whereas the sensitivity of baroreflex of modulate heart rate is unchanged during posthandgrip muscle ischemia.

  13. Stiff muscle fibers in calf muscles of patients with cerebral palsy lead to high passive muscle stiffness.

    Science.gov (United States)

    Mathewson, Margie A; Chambers, Henry G; Girard, Paul J; Tenenhaus, Mayer; Schwartz, Alexandra K; Lieber, Richard L

    2014-12-01

    Cerebral palsy (CP), caused by an injury to the developing brain, can lead to alterations in muscle function. Subsequently, increased muscle stiffness and decreased joint range of motion are often seen in patients with CP. We examined mechanical and biochemical properties of the gastrocnemius and soleus muscles, which are involved in equinus muscle contracture. Passive mechanical testing of single muscle fibers from gastrocnemius and soleus muscle of patients with CP undergoing surgery for equinus deformity showed a significant increase in fiber stiffness (p<0.01). Bundles of fibers that included their surrounding connective tissues showed no stiffness difference (p=0.28).). When in vivo sarcomere lengths were measured and fiber and bundle stiffness compared at these lengths, both fibers and bundles of patients with CP were predicted to be much stiffer in vivo compared to typically developing (TD) individuals. Interestingly, differences in fiber and bundle stiffness were not explained by typical biochemical measures such as titin molecular weight (a giant protein thought to impact fiber stiffness) or collagen content (a proxy for extracellular matrix amount). We suggest that the passive mechanical properties of fibers and bundles are thus poorly understood. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  14. Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

    International Nuclear Information System (INIS)

    Chatterjee, Somik; Yin, Hongshan; Nam, Deokhwa; Li, Yong; Ma, Ke

    2015-01-01

    Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1 −/− mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation

  15. Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Somik [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yin, Hongshan [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Cardiovascular Medicine, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050051, Hebei (China); Nam, Deokhwa [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Li, Yong [Department of Pediatric Surgery, Center for Stem Cell Research and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030 (United States); Ma, Ke, E-mail: kma@houstonmethodist.org [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States)

    2015-02-01

    Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1{sup −/−} mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation.

  16. Neuropathic Pain-like Alterations in Muscle Nociceptor Function Associated with Vibration-induced Muscle Pain

    OpenAIRE

    Chen, Xiaojie; Green, Paul G.; Levine, Jon D.

    2010-01-01

    We recently developed a rodent model of the painful muscle disorders induced by occupational exposure to vibration. In the present study we used this model to evaluate the function of sensory neurons innervating the vibration-exposed gastrocnemius muscle. Activity of 74 vibration-exposed and 40 control nociceptors, with mechanical receptive fields in the gastrocnemius muscle, were recorded. In vibration-exposed rats ~15% of nociceptors demonstrated an intense and long-lasting barrage of actio...

  17. Detection of muscle gap by L-BIA in muscle injuries: clinical prognosis.

    Science.gov (United States)

    Nescolarde, L; Yanguas, J; Terricabras, J; Lukaski, H; Alomar, X; Rosell-Ferrer, J; Rodas, G

    2017-06-21

    Sport-related muscle injury classifications are based basically on imaging criteria such as ultrasound (US) and magnetic resonance imaging (MRI) without consensus because of a lack of clinical prognostics for return-to-play (RTP), which is conditioned upon the severity of the injury, and this in turn with the muscle gap (muscular fibers retraction). Recently, Futbol Club Barcelona's medical department proposed a new muscle injury classification in which muscle gap plays an important role, with the drawback that it is not always possible to identify by MRI. Localized bioimpedance measurement (L-BIA) has emerged as a non-invasive technique for supporting US and MRI to quantify the disrupted soft tissue structure in injured muscles. To correlate the severity of the injury according to the gap with the RTP, through the percent of change in resistance (R), reactance (Xc) and phase-angle (PA) by L-BIA measurements in 22 muscle injuries. After grouping the data according to the muscle gap (by MRI exam), there were significant differences in R between grade 1 and grade 2f (myotendinous or myofascial muscle injury with feather-like appearance), as well as between grade 2f and grade 2g (myotendinous or myofascial muscle injury with feather and gap). The Xc and PA values decrease significantly between each grade (i.e. 1 versus 2f, 1 versus 2g and 2f versus 2g). In addition, the severity of the muscle gap adversely affected the RTP with significant differences observed between 1 and 2g as well as between 2f and 2g. These results show that L-BIA could aid MRI and US in identifying the severity of an injured muscle according to muscle gap and therefore to accurately predict the RTP.

  18. An Autologous Muscle Tissue Expansion Approach for the Treatment of Volumetric Muscle Loss

    Science.gov (United States)

    2015-07-01

    DOI: 10.1089/ biores.2015.0009. Abbreviations Used ANOVA¼ analysis of variance ECM¼ extracellular matrix EDL¼ extensor digitorum longus TA¼ tibialis...muscle VML injury VML was surgically created in similar fashion to that previously reported.2,13,17 The TA and underlying ex- tensor digitorum longus ...made at the antero-lateral aspect of the ankle and the distal EDL muscle tendon and extensor hallicus longus muscle was isolated and severed above the

  19. Histological evidence for muscle insertion in extant amniote femora: implications for muscle reconstruction in fossils.

    Science.gov (United States)

    Petermann, Holger; Sander, Martin

    2013-04-01

    Since the 19th century, identification of muscle attachment sites on bones has been important for muscle reconstructions, especially in fossil tetrapods, and therefore has been the subject of numerous biological and paleontological studies. At the microscopic level, in histological thin sections, the only features that can be used reliably for identifying tendon-bone or muscle-tendon-bone interactions are Sharpey's fibers. Muscles, however, do not only attach to the bone indirectly with tendons, but also directly. Previous studies failed to provide new indicators for muscle attachment, or to address the question of whether muscles with direct attachment can be identified histologically. However, histological identification of direct muscle attachments is important because these attachments do not leave visible marks (e.g. scars and rugosities) on the bone surface. We dissected the right hind limb and mapped the muscle attachment sites on the femur of one rabbit (Oryctolagus cuniculus), one Alligator mississippiensis, and one turkey (Meleagris cuniculus). We then extracted the femur and prepared four histological thin sections for the rabbit and the turkey and five histological thin sections for the alligator. Sharpey's fibers, vascular canal orientation, and a frayed periosteal margin can be indicators for indirect but also direct muscle attachment. Sharpey's fibers can be oriented to the cutting plane of the thin section at high angles, and two Sharpey's fibers orientations can occur in one area, possibly indicating a secondary force axis. However, only about 60% of mapped muscle attachment sites could be detected in thin sections, and frequently histological features suggestive of muscle attachment occurred outside mapped sites. While these insights should improve our ability to successfully identify and reconstruct muscles in extinct species, they also show the limitations of this approach. © 2013 The Authors Journal of Anatomy © 2013 Anatomical Society.

  20. Muscle activation patterns when passively stretching spastic lower limb muscles of children with cerebral palsy.

    Science.gov (United States)

    Bar-On, Lynn; Aertbeliën, Erwin; Molenaers, Guy; Desloovere, Kaat

    2014-01-01

    The definition of spasticity as a velocity-dependent activation of the tonic stretch reflex during a stretch to a passive muscle is the most widely accepted. However, other mechanisms are also thought to contribute to pathological muscle activity and, in patients post-stroke and spinal cord injury can result in different activation patterns. In the lower-limbs of children with spastic cerebral palsy (CP) these distinct activation patterns have not yet been thoroughly explored. The aim of the study was to apply an instrumented assessment to quantify different muscle activation patterns in four lower-limb muscles of children with CP. Fifty-four children with CP were included (males/females n = 35/19; 10.8 ± 3.8 yrs; bilateral/unilateral involvement n =  32/22; Gross Motor Functional Classification Score I-IV) of whom ten were retested to evaluate intra-rater reliability. With the subject relaxed, single-joint, sagittal-plane movements of the hip, knee, and ankle were performed to stretch the lower-limb muscles at three increasing velocities. Muscle activity and joint motion were synchronously recorded using inertial sensors and electromyography (EMG) from the adductors, medial hamstrings, rectus femoris, and gastrocnemius. Muscles were visually categorised into activation patterns using average, normalized root mean square EMG (RMS-EMG) compared across increasing position zones and velocities. Based on the visual categorisation, quantitative parameters were defined using stretch-reflex thresholds and normalized RMS-EMG. These parameters were compared between muscles with different activation patterns. All patterns were dominated by high velocity-dependent muscle activation, but in more than half, low velocity-dependent activation was also observed. Muscle activation patterns were found to be both muscle- and subject-specific (pstretches was found to be the most sensitive in categorizing muscles into activation patterns (pmuscles with different patterns react