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Sample records for muscle function palpation

  1. Relationship among vaginal palpation, vaginal squeeze pressure, electromyographic and ultrasonographic variables of female pelvic floor muscles

    Directory of Open Access Journals (Sweden)

    Vanessa S. Pereira

    2014-10-01

    Full Text Available Background: The proper evaluation of the pelvic floor muscles (PFM is essential for choosing the correct treatment. Currently, there is no gold standard for the assessment of female PFM function. Objective: To determine the correlation between vaginal palpation, vaginal squeeze pressure, and electromyographic and ultrasonographic variables of the female PFM. Method: This cross-sectional study evaluated 80 women between 18 and 35 years of age who were nulliparous and had no pelvic floor dysfunction. PFM function was assessed based on digital palpation, vaginal squeeze pressure, electromyographic activity, bilateral diameter of the bulbocavernosus muscles and the amount of bladder neck movement during voluntary PFM contraction using transperineal bi-dimensional ultrasound. The Pearson correlation was used for statistical analysis (p<0.05. Results: There was a strong positive correlation between PFM function and PFM contraction pressure (0.90. In addition, there was a moderate positive correlation between these two variables and PFM electromyographic activity (0.59 and 0.63, respectively and movement of the bladder neck in relation to the pubic symphysis (0.51 and 0.60, respectively. Conclusions: This study showed that there was a correlation between vaginal palpation, vaginal squeeze pressure, and electromyographic and ultrasonographic variables of the PFM in nulliparous women. The strong correlation between digital palpation and PFM contraction pressure indicated that perineometry could easily be replaced by PFM digital palpation in the absence of equipment.

  2. Correlation of Digital Palpation and Transabdominal Ultrasound for Assessment of Pelvic Floor Muscle Contraction

    OpenAIRE

    Arab, Amir Massoud; Behbahani, Roxana Bazaz; Lorestani, Leila; Azari, Afsaneh

    2009-01-01

    Pelvic floor muscle (PFM) dysfunction has been commonly associated with urinary disorders and lumbo-pelvic pain. Transabdominal (TA) ultrasound is currently used by physical therapists to assess PFM function. Controversy exists regarding the correlation between TA ultrasound measurement and vaginal palpation for assessment of PFM contraction, and this relationship has not yet been examined concurrently during the same contraction. The purpose of this study was to determine the correlation of ...

  3. Review on Laryngeal Palpation Methods in Muscle Tension Dysphonia: Validity and Reliability Issues.

    Science.gov (United States)

    Khoddami, Seyyedeh Maryam; Ansari, Noureddin Nakhostin; Jalaie, Shohreh

    2015-07-01

    Laryngeal palpation is a common clinical method for the assessment of neck and laryngeal muscles in muscle tension dysphonia (MTD). To review the available laryngeal palpation methods used in patients with MTD for the assessment, diagnosis, or document of treatment outcomes. A systematic review of the literature concerning palpatory methods in MTD was conducted using the databases MEDLINE (PubMed), ScienceDirect, Scopus, Web of science, Web of knowledge and Cochrane Library between July and October 2013. Relevant studies were identified by one reviewer based on screened titles/abstracts and full texts. Manual searching was also used to track the source literature. There were five main as well as miscellaneous palpation methods that were different according to target anatomical structures, judgment or grading system, and using tasks. There were only a few scales available, and the majority of the palpatory methods were qualitative. Most of the palpatory methods evaluate the tension at both static and dynamic tasks. There was little information about the validity and reliability of the available methods. The literature on the scientific evidence of muscle tension indicators perceived by laryngeal palpation in MTD is scarce. Future studies should be conducted to investigate the validity and reliability of palpation methods. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  4. Can palpation-induced muscle pain pattern contribute to the differential diagnosis among temporomandibular disorders, primary headaches phenotypes and possible bruxism?

    Science.gov (United States)

    Porporatti, André-Luís; Calderon, Patrícia-dos-Santos; Conti, Paulo-César-Rodrigues; Bonjardim, Leonardo-Rigoldi

    2016-01-01

    Background The evaluation of possible differences in the distribution or characteristics of palpation-induced pain in the masticatory muscles could be valuable in terms of diagnostic assessment. The aim of this study was to evaluate the impact of different combinations of anterior temporalis (AT) and masseter palpation-induced pain in the diagnostic of temporomandibular disorder (TMD), primary headaches and bruxism. Material and Methods A total of 1200 dental records of orofacial pain adult patients were analyzed. The outcomes were dichotomously classified (presence/absence) as following: a) AT and/or masseter palpation-induced pain; b) myogenous TMD; c) temporomandibular joint (TMJ) arthralgia (arthrogenous TMD); d) migraine; e) tension-type headache (TTH); f) self-reported bruxism. Binomial logistic regression model (α = 5%) was applied to the data considering the palpation-induced muscle pain as the dependent variable. Results Mean age (SD) were 35.7 years (13.4) for 635 included dental records (83% females). Myogenous and arthrogenous TMD, migraine, TTH and bruxism were mainly associated with, respectively, masseter palpation-induced pain (ppain (ppain (ppain (p=0.009 - OR=1.62, 95%CI 1.12-2.33) and bilateral masseter palpation-induced pain (p=0.01 - OR=1.74, 95%CI 1.13-2.69). Conclusions Palpation-induced pain in the masticatory muscles may play a role in the differential diagnosis among painful TMD, primary headaches and bruxism. Key words:Diagnosis, temporomandibular joint disorders, migraine, tension-type headache, bruxism. PMID:26615507

  5. Can palpation-induced muscle pain pattern contribute to the differential diagnosis among temporomandibular disorders, primary headaches phenotypes and possible bruxism?

    Science.gov (United States)

    Costa, Yuri-Martins; Porporatti, André-Luís; Calderon, Patrícia-dos-Santos; Conti, Paulo-César-Rodrigues; Bonjardim, Leonardo-Rigoldi

    2016-01-01

    The evaluation of possible differences in the distribution or characteristics of palpation-induced pain in the masticatory muscles could be valuable in terms of diagnostic assessment. The aim of this study was to evaluate the impact of different combinations of anterior temporalis (AT) and masseter palpation-induced pain in the diagnostic of temporomandibular disorder (TMD), primary headaches and bruxism. A total of 1200 dental records of orofacial pain adult patients were analyzed. The outcomes were dichotomously classified (presence/absence) as following: a) AT and/or masseter palpation-induced pain; b) myogenous TMD; c) temporomandibular joint (TMJ) arthralgia (arthrogenous TMD); d) migraine; e) tension-type headache (TTH); f) self-reported bruxism. Binomial logistic regression model (α = 5%) was applied to the data considering the palpation-induced muscle pain as the dependent variable. Mean age (SD) were 35.7 years (13.4) for 635 included dental records (83% females). Myogenous and arthrogenous TMD, migraine, TTH and bruxism were mainly associated with, respectively, masseter palpation-induced pain (pbruxism.

  6. Extraocular muscle function testing

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003397.htm Extraocular muscle function testing To use the sharing features on this page, please enable JavaScript. Extraocular muscle function testing examines the function of the eye muscles. ...

  7. Test imf kursus - Referred Pain and Sensations Evoked by Standardized Palpation of the Masseter Muscle in Healthy Participants

    DEFF Research Database (Denmark)

    Masuda, Manabu; Iida, Takashi; Exposto, Fernando G

    2018-01-01

    , Tukey post hoc, and McNemar's tests with a 5% level of significance. RESULTS: Referred pain/sensations were most commonly evoked with the 2.0-kg stimulus (34.4% of participants; P significant effects of stimulus intensity on NRS...... scores for pain and unpleasantness, as well as for aftersensation (P significant effects on NRS scores for pain and unpleasantness for the 1.0- and 2.0-kg stimuli (P 2.0-kg stimulus (P .... The right masseter muscle was divided into 15 test sites. Mechanical sensitivity of the masseter was assessed with three mechanical stimuli (0.5 kg, 1.0 kg, or 2.0 kg) applied by palpometers to the 15 test sites for 5 seconds each site. Participants scored the perceived intensity of pain and unpleasantness...

  8. Muscle function loss

    Science.gov (United States)

    ... or head are damaged, you may have difficulty chewing and swallowing or closing your eyes. In these ... Medical Professional Muscle paralysis always requires immediate medical attention. If you notice gradual weakening or problems with ...

  9. Combined Functional Voice Therapy in Singers With Muscle Tension Dysphonia in Singing.

    Science.gov (United States)

    Sielska-Badurek, Ewelina; Osuch-Wójcikiewicz, Ewa; Sobol, Maria; Kazanecka, Ewa; Rzepakowska, Anna; Niemczyk, Kazimierz

    2017-07-01

    The purpose of this study was to evaluate vocal tract function and the voice quality in singers with muscle tension dysphonia (MTD) after undergoing combined functional voice therapy of the singing voice. This is a prospective, randomized study. Forty singers (29 females and 11 males, mean age: 24.6 ± 8.8 years) with MTD were enrolled in the study. The study group consisted of 20 singers who underwent combined functional voice therapy (10-15 individual sessions, 30-40 minutes each). Singers who did not opt for vocal rehabilitation consisted of the control group. Effects of rehabilitation were assessed with videolaryngostroboscopy, palpation of the vocal tract structures, flexible fiberoptic evaluation of the pharynx and the larynx, perceptual speaking and singing voice assessment, acoustic analysis, maximal phonation time, and the Voice Handicap Index. After combined functional voice therapy in the study group, great improvement was noticed in palpation of the vocal tract structures (P singing range obtained from acoustic analysis of glissando (P singing. Development of palpation and perceptual singing voice examination protocols enables one to compare results before and after rehabilitation in clinics. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  10. Palpation- and ultrasound-guided brachial plexus blockade in Hispaniolan Amazon parrots (Amazona ventralis).

    Science.gov (United States)

    da Cunha, Anderson F; Strain, George M; Rademacher, Nathalie; Schnellbacher, Rodney; Tully, Thomas N

    2013-01-01

    To compare palpation-guided with ultrasound-guided brachial plexus blockade in Hispaniolan Amazon parrots. Prospective randomized experimental trial. Eighteen adult Hispaniolan Amazon parrots (Amazona ventralis) weighing 252-295 g. After induction of anesthesia with isoflurane, parrots received an injection of lidocaine (2 mg kg(-1)) in a total volume of 0.3 mL at the axillary region. The birds were randomly assigned to equal groups using either palpation or ultrasound as a guide for the brachial plexus block. Nerve evoked muscle potentials (NEMP) were used to monitor effectiveness of brachial plexus block. The palpation-guided group received the local anesthetic at the space between the pectoral muscle, triceps, and supracoracoideus aticimus muscle, at the insertion of the tendons of the caudal coracobrachial muscle, and the caudal scapulohumeral muscle. For the ultrasound-guided group, the brachial plexus and the adjacent vessels were located with B-mode ultrasonography using a 7-15 MHz linear probe. After location, an 8-5 MHz convex transducer was used to guide injections. General anesthesia was discontinued 20 minutes after lidocaine injection and the birds recovered in a padded cage. Both techniques decreased the amplitude of NEMP. Statistically significant differences in NEMP amplitudes, were observed within the ultrasound-guided group at 5, 10, 15, and 20 minutes after injection and within the palpation-guided group at 10, 15, and 20 minutes after injection. There was no statistically significant difference between the two groups. No effect on motor function, muscle relaxation or wing droop was observed after brachial plexus block. The onset of the brachial plexus block tended to be faster when ultrasonography was used. Brachial plexus injection can be performed in Hispaniolan Amazon parrots and nerve evoked muscle potentials were useful to monitor the effects on nerve conduction in this avian species. Neither technique produced an effective block at the

  11. A survey of simulators for palpation training.

    Science.gov (United States)

    Zhang, Yan; Phillips, Roger; Ward, James; Pisharody, Sandhya

    2009-01-01

    Palpation is a widely used diagnostic method in medical practice. The sensitivity of palpation is highly dependent upon the skill of clinicians, which is often difficult to master. There is a need of simulators in palpation training. This paper summarizes important work and the latest achievements in simulation for palpation training. Three types of simulators; physical models, Virtual Reality (VR) based simulations, and hybrid (computerized and physical) simulators, are surveyed. Comparisons among different kinds of simulators are presented.

  12. 38 CFR 4.78 - Muscle function.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Muscle function. 4.78... DISABILITIES Disability Ratings The Organs of Special Sense § 4.78 Muscle function. (a) Examination of muscle function. The examiner must use a Goldmann perimeter chart that identifies the four major quadrants (upward...

  13. Architectural design of the pelvic floor is consistent with muscle functional subspecialization.

    Science.gov (United States)

    Tuttle, Lori J; Nguyen, Olivia T; Cook, Mark S; Alperin, Marianna; Shah, Sameer B; Ward, Samuel R; Lieber, Richard L

    2014-02-01

    Skeletal muscle architecture is the strongest predictor of a muscle's functional capacity. The purpose of this study was to define the architectural properties of the deep muscles of the female pelvic floor (PFMs) to elucidate their structure-function relationships. PFMs coccygeus (C), iliococcygeus (IC), and pubovisceral (PV) were harvested en bloc from ten fixed human cadavers (mean age 85 years, range 55-102). Fundamental architectural parameters of skeletal muscles [physiological cross-sectional area (PCSA), normalized fiber length, and sarcomere length (L(s))] were determined using validated methods. PCSA predicts muscle-force production, and normalized fiber length is related to muscle excursion. These parameters were compared using repeated measures analysis of variance (ANOVA) with post hoc t tests, as appropriate. Significance was set to α = 0.05. PFMs were thinner than expected based on data reported from imaging studies and in vivo palpation. Significant differences in fiber length were observed across PFMs: C = 5.29 ± 0.32 cm, IC = 7.55 ± 0.46 cm, PV = 10.45 ± 0.67 cm (p design shows individual muscles demonstrating differential architecture, corresponding to specialized function in the pelvic floor.

  14. 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

  15. 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

  16. Comparison of techniques used for functional evaluation of pelvic floor muscles

    Directory of Open Access Journals (Sweden)

    Christiane Kelen Lucena da Costa

    2017-06-01

    Full Text Available Objective: To identify and discuss techniques for evaluation of pelvic floor muscles (PFM focusing on the most used and accessible techniques in health care. Methods: This is a quantitative exploratory and descriptive applied research. Data were collected from March to June 2016 at a higher education institution in the city of João Pessoa, Paraíba, Brazil. Initially, 31 healthy young women were submitted to pelvic floor evaluation using the following methods: PERFECT, vaginal cones, and perineometry using Perine and Peritron. The participants then performed exercises to strengthen PFM. The variables measured by the different methods were also recorded 30 and 60 days after the start of the program. ANOVA was used for repeated measures and Spearman's correlation test was used for the evaluation instruments with significance set at 5%. Results: The functional evaluation using all the methods was adequate in the PFM evaluation. In the digital palpation (PERFECT, the endurance response (E was positively correlated to Perina (rho=0.688 and vaginal cones (rho=0.571, and muscle strength (P was positively correlated to the Peritron technique (rho=0.506. Conclusion: There are several ways to evaluate PFM function and all of them provide sensory feedback to the patient. Given the low costs of digital palpation, the introduction of this technique into women's health services is likely to improve women's quality of life.

  17. Palpation of the upper thoracic spine

    DEFF Research Database (Denmark)

    Christensen, Henrik Wulff; Vach, Werner; Vach, Kirstin

    2002-01-01

    procedure. RESULTS: Using an "expanded" definition of agreement that accepts small inaccuracies (+/-1 segment) in the numbering of spinal segments, we found--based on the pooled data from the thoracic spine--kappa values of 0.59 to 0.77 for the hour-to-hour and the day-to-day intraobserver reliability......OBJECTIVE: To assess the intraobserver reliability (in terms of hour-to-hour and day-to-day reliability) and the interobserver reliability with 3 palpation procedures for the detection of spinal biomechanic dysfunction in the upper 8 segments of the thoracic spine. DESIGN: A repeated....... INTERVENTION: Three types of palpation were performed: Sitting motion palpation and prone motion palpation for biomechanic dysfunction and paraspinal palpation for tenderness. Each dimension was rated as "absent" or "present" for each segment. All examinations were performed according to a standard written...

  18. AMPK in skeletal muscle function and metabolism

    DEFF Research Database (Denmark)

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

    2018-01-01

    Skeletal muscle possesses a remarkable ability to adapt to various physiologic conditions. AMPK is a sensor of intracellular energy status that maintains energy stores by fine-tuning anabolic and catabolic pathways. AMPK's role as an energy sensor is particularly critical in tissues displaying...... 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...

  19. 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.

  20. An education program about pelvic floor muscles improved women's knowledge but not pelvic floor muscle function, urinary incontinence or sexual function: a randomised trial.

    Science.gov (United States)

    de Andrade, Roberta Leopoldino; Bø, Kari; Antonio, Flavia Ignácio; Driusso, Patricia; Mateus-Vasconcelos, Elaine Cristine Lemes; Ramos, Salvador; Julio, Monica Pitanguy; Ferreira, Cristine Homsi Jorge

    2018-04-01

    Does an educational program with instructions for performing 'the Knack' improve voluntary contraction of the pelvic floor muscles, reduce reports of urinary incontinence, improve sexual function, and promote women's knowledge of the pelvic floor muscles? Randomised, controlled trial with concealed allocation, intention-to-treat analysis and blinded assessors. Ninety-nine women from the local community. The experimental group (n=50) received one lecture per week for 4 weeks, and instructions for performing 'the Knack'. The control group (n=49) received no intervention. The primary outcome was maximum voluntary contraction of the pelvic floor muscles measured using manometry. Secondary outcomes were: ability to contract the pelvic floor muscles measured using vaginal palpation; severity of urinary incontinence measured by the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) scored from 0 to 21; self-reported sexual function; and knowledge related to the pelvic floor. Outcomes were measured at baseline and after 4 weeks. The intervention did not significantly improve: maximum voluntary contraction (MD 2.7 cmH 2 O higher in the experimental group, 95% CI -0.5 to 5.9); ability to contract the pelvic floor muscles (RR 2.18, 95% CI 0.49 to 9.65); or self-reported severity of urinary incontinence (MD 1 point greater reduction in the experimental group, 95% CI -3 to 1). Sexual function did not significantly differ between groups, but very few of the women engaged in sexual activity during the study period. The educational program did, however, significantly increase women's knowledge related to the location, functions and dysfunctions of the pelvic floor muscles, and treatment options. Education and teaching women to perform 'the Knack' had no significant effect on voluntary contraction of the pelvic floor muscles, urinary incontinence or sexual function, but it promoted women's knowledge about the pelvic floor. Brazilian Registry of Clinical

  1. An education program about pelvic floor muscles improved women’s knowledge but not pelvic floor muscle function, urinary incontinence or sexual function: a randomised trial

    Directory of Open Access Journals (Sweden)

    Roberta Leopoldino de Andrade

    2018-04-01

    Full Text Available Question: Does an educational program with instructions for performing ‘the Knack’ improve voluntary contraction of the pelvic floor muscles, reduce reports of urinary incontinence, improve sexual function, and promote women’s knowledge of the pelvic floor muscles? Design: Randomised, controlled trial with concealed allocation, intention-to-treat analysis and blinded assessors. Participants: Ninety-nine women from the local community. Intervention: The experimental group (n = 50 received one lecture per week for 4 weeks, and instructions for performing ‘the Knack’. The control group (n = 49 received no intervention. Outcome measures: The primary outcome was maximum voluntary contraction of the pelvic floor muscles measured using manometry. Secondary outcomes were: ability to contract the pelvic floor muscles measured using vaginal palpation; severity of urinary incontinence measured by the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF scored from 0 to 21; self-reported sexual function; and knowledge related to the pelvic floor. Outcomes were measured at baseline and after 4 weeks. Results: The intervention did not significantly improve: maximum voluntary contraction (MD 2.7 cmH2O higher in the experimental group, 95% CI –0.5 to 5.9; ability to contract the pelvic floor muscles (RR 2.18, 95% CI 0.49 to 9.65; or self-reported severity of urinary incontinence (MD 1 point greater reduction in the experimental group, 95% CI –3 to 1. Sexual function did not significantly differ between groups, but very few of the women engaged in sexual activity during the study period. The educational program did, however, significantly increase women’s knowledge related to the location, functions and dysfunctions of the pelvic floor muscles, and treatment options. Conclusion: Education and teaching women to perform ‘the Knack’ had no significant effect on voluntary contraction of the pelvic floor muscles

  2. Testosterone Replacement, Muscle Strength, and Physical Function

    Directory of Open Access Journals (Sweden)

    You-Seon Nam

    2018-05-01

    Full Text Available Muscle strength and physical function decrease in older men, as do testosterone levels. Nonetheless, the effects of testosterone replacement therapy on muscle strength and physical function remain inconclusive and equivocal. We conducted a rapid systematic review, the results of which showed that testosterone replacement does not affect muscle strength (measured by hand grip strength and leg muscle strength, although it may increase physical function (measured by the 6-minute walk test, Physical Activity Scale for the Elderly score, and other physical performance tests. However, most of the studies were conducted in the United States or Europe and did not include participants from Asian or other ethnic backgrounds; therefore, further studies are needed to evaluate the effects of testosterone replacement in a broader population.

  3. Effect of statins on skeletal muscle function.

    Science.gov (United States)

    Parker, Beth A; Capizzi, Jeffrey A; Grimaldi, Adam S; Clarkson, Priscilla M; Cole, Stephanie M; Keadle, Justin; Chipkin, Stuart; Pescatello, Linda S; Simpson, Kathleen; White, C Michael; Thompson, Paul D

    2013-01-01

    Many clinicians believe that statins cause muscle pain, but this has not been observed in clinical trials, and the effect of statins on muscle performance has not been carefully studied. The Effect of Statins on Skeletal Muscle Function and Performance (STOMP) study assessed symptoms and measured creatine kinase, exercise capacity, and muscle strength before and after atorvastatin 80 mg or placebo was administered for 6 months to 420 healthy, statin-naive subjects. No individual creatine kinase value exceeded 10 times normal, but average creatine kinase increased 20.8±141.1 U/L (Pmuscle strength or exercise capacity with atorvastatin, but more atorvastatin than placebo subjects developed myalgia (19 versus 10; P=0.05). Myalgic subjects on atorvastatin or placebo had decreased muscle strength in 5 of 14 and 4 of 14 variables, respectively (P=0.69). These results indicate that high-dose atorvastatin for 6 months does not decrease average muscle strength or exercise performance in healthy, previously untreated subjects. Nevertheless, this blinded, controlled trial confirms the undocumented impression that statins increase muscle complaints. Atorvastatin also increased average creatine kinase, suggesting that statins produce mild muscle injury even among asymptomatic subjects. This increase in creatine kinase should prompt studies examining the effects of more prolonged, high-dose statin treatment on muscular performance. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00609063.

  4. Abdominal muscle function and incisional hernia

    DEFF Research Database (Denmark)

    Jensen, K K; Kjaer, M; Jorgensen, L N

    2014-01-01

    PURPOSE: Although ventral incisional hernia (VIH) repair in patients is often evaluated in terms of hernia recurrence rate and health-related quality of life, there is no clear consensus regarding optimal operative treatment based on these parameters. It was proposed that health-related quality...... of life depends largely on abdominal muscle function (AMF), and the present review thus evaluates to what extent AMF is influenced by VIH and surgical repair. METHODS: The PubMed and EMBASE databases were searched for articles following a systematic strategy for inclusion. RESULTS: A total of seven...... studies described AMF in relation to VIH. Five studies examined AMF using objective isokinetic dynamometers to determine muscle strength, and two studies examined AMF by clinical examination-based muscle tests. CONCLUSION: Both equipment-related and functional muscle tests exist for use in patients...

  5. Lower extremity muscle functions during full squats.

    Science.gov (United States)

    Robertson, D G E; Wilson, Jean-Marie J; St Pierre, Taunya A

    2008-11-01

    The purpose of this research was to determine the functions of the gluteus maximus, biceps femoris, semitendinosus, rectus femoris, vastus lateralis, soleus, gastrocnemius, and tibialis anterior muscles about their associated joints during full (deep-knee) squats. Muscle function was determined from joint kinematics, inverse dynamics, electromyography, and muscle length changes. The subjects were six experienced, male weight lifters. Analyses revealed that the prime movers during ascent were the monoarticular gluteus maximus and vasti muscles (as exemplified by vastus lateralis) and to a lesser extent the soleus muscles. The biarticular muscles functioned mainly as stabilizers of the ankle, knee, and hip joints by working eccentrically to control descent or transferring energy among the segments during scent. During the ascent phase, the hip extensor moments of force produced the largest powers followed by the ankle plantar flexors and then the knee extensors. The hip and knee extensors provided the initial bursts of power during ascent with the ankle extensors and especially a second burst from the hip extensors adding power during the latter half of the ascent.

  6. Anatomy and function of the hypothenar muscles.

    Science.gov (United States)

    Pasquella, John A; Levine, Pam

    2012-02-01

    The hypothenar eminence is the thick soft tissue mass located on the ulnar side of the palm. Understanding its location and contents is important for understanding certain aspects of hand function. Variation in motor nerve distribution of the hypothenar muscles makes surgery of the ulnar side of the palm more challenging. To avoid injury to nerve branches, knowledge of these differences is imperative. This article discusses the muscular anatomy and function, vascular anatomy, and nerve anatomy and innervation of the hypothenar muscles. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Mechanomyogram for muscle function assessment: a review.

    Directory of Open Access Journals (Sweden)

    Md Anamul Islam

    Full Text Available Mechanomyography (MMG has been extensively applied in clinical and experimental practice to examine muscle characteristics including muscle function (MF, prosthesis and/or switch control, signal processing, physiological exercise, and medical rehabilitation. Despite several existing MMG studies of MF, there has not yet been a review of these. This study aimed to determine the current status on the use of MMG in measuring the conditions of MFs.Five electronic databases were extensively searched for potentially eligible studies published between 2003 and 2012. Two authors independently assessed selected articles using an MS-Word based form created for this review. Several domains (name of muscle, study type, sensor type, subject's types, muscle contraction, measured parameters, frequency range, hardware and software, signal processing and statistical analysis, results, applications, authors' conclusions and recommendations for future work were extracted for further analysis. From a total of 2184 citations 119 were selected for full-text evaluation and 36 studies of MFs were identified. The systematic results find sufficient evidence that MMG may be used for assessing muscle fatigue, strength, and balance. This review also provides reason to believe that MMG may be used to examine muscle actions during movements and for monitoring muscle activities under various types of exercise paradigms.Overall judging from the increasing number of articles in recent years, this review reports sufficient evidence that MMG is increasingly being used in different aspects of MF. Thus, MMG may be applied as a useful tool to examine diverse conditions of muscle activity. However, the existing studies which examined MMG for MFs were confined to a small sample size of healthy population. Therefore, future work is needed to investigate MMG, in examining MFs between a sufficient number of healthy subjects and neuromuscular patients.

  8. Clinical abdominal palpation for predicting oligohydramnios in ...

    African Journals Online (AJOL)

    Objective. In view of the scarcity of ultrasound in low-resource settings, to evaluate abdominal palpation for prediction of oligohydramnios in suspected prolonged pregnancy, using the ultrasound-obtained amniotic fluid index (AFI) as a gold standard, taking into account maternal and fetal factors that may affect amniotic fluid ...

  9. Structure-function relationship of skeletal muscle provides inspiration for design of new artificial muscle

    Science.gov (United States)

    Gao, Yingxin; Zhang, Chi

    2015-03-01

    A variety of actuator technologies have been developed to mimic biological skeletal muscle that generates force in a controlled manner. Force generation process of skeletal muscle involves complicated biophysical and biochemical mechanisms; therefore, it is impossible to replace biological muscle. In biological skeletal muscle tissue, the force generation of a muscle depends not only on the force generation capacity of the muscle fiber, but also on many other important factors, including muscle fiber type, motor unit recruitment, architecture, structure and morphology of skeletal muscle, all of which have significant impact on the force generation of the whole muscle or force transmission from muscle fibers to the tendon. Such factors have often been overlooked, but can be incorporated in artificial muscle design, especially with the discovery of new smart materials and the development of innovative fabrication and manufacturing technologies. A better understanding of the physiology and structure-function relationship of skeletal muscle will therefore benefit the artificial muscle design. In this paper, factors that affect muscle force generation are reviewed. Mathematical models used to model the structure-function relationship of skeletal muscle are reviewed and discussed. We hope the review will provide inspiration for the design of a new generation of artificial muscle by incorporating the structure-function relationship of skeletal muscle into the design of artificial muscle.

  10. Structure–function relationship of skeletal muscle provides inspiration for design of new artificial muscle

    International Nuclear Information System (INIS)

    Gao, Yingxin; Zhang, Chi

    2015-01-01

    A variety of actuator technologies have been developed to mimic biological skeletal muscle that generates force in a controlled manner. Force generation process of skeletal muscle involves complicated biophysical and biochemical mechanisms; therefore, it is impossible to replace biological muscle. In biological skeletal muscle tissue, the force generation of a muscle depends not only on the force generation capacity of the muscle fiber, but also on many other important factors, including muscle fiber type, motor unit recruitment, architecture, structure and morphology of skeletal muscle, all of which have significant impact on the force generation of the whole muscle or force transmission from muscle fibers to the tendon. Such factors have often been overlooked, but can be incorporated in artificial muscle design, especially with the discovery of new smart materials and the development of innovative fabrication and manufacturing technologies. A better understanding of the physiology and structure–function relationship of skeletal muscle will therefore benefit the artificial muscle design. In this paper, factors that affect muscle force generation are reviewed. Mathematical models used to model the structure–function relationship of skeletal muscle are reviewed and discussed. We hope the review will provide inspiration for the design of a new generation of artificial muscle by incorporating the structure–function relationship of skeletal muscle into the design of artificial muscle. (topical review)

  11. Muscle function of the pelvic floor in healthy, puerperal women with pelvic floor dysfunction.

    Science.gov (United States)

    Castro-Pardiñas, M A; Torres-Lacomba, M; Navarro-Brazález, B

    2017-05-01

    To understand the function of the pelvic floor muscles (PFM) at different ages in healthy women and in puerperal women with pelvic floor dysfunctions (PFD) and to ascertain whether there are differences among them. A descriptive cross-sectional study was conducted between June 2014 and September 2016 and included 177 women, 70 of whom had no symptoms of PFD, 53 primiparous mothers in late postpartum and 54 with PFD. The function of the PFM was measured through vaginal palpation (quality of the contraction); manometry (force); dynamometer (tone, strength, and response to stretching), and surface electromyography (neuromuscular activity and resistance). The healthy women showed superior values for PFM tone, maximum strength, neuromuscular activity and resistance than the puerperal mothers and the women with PFD (P.05). The muscle function of the healthy women did not vary significantly with age, except in the case of tone, which was lower in the women older than 46 years (P=.004). Age and births decrease the baseline tone of the PFM in healthy women. Therefore, lower strength, resistance and neuromuscular activity appear to be the main difference between the PFM of women with PFD and the PFM of healthy women. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Standardized simulated palpation training--development of a palpation trainer and assessment of palpatory skills in experienced and inexperienced clinicians

    DEFF Research Database (Denmark)

    Larsen, Anders Holsgaard; Myburgh, Corrie; Hartvigsen, Jan

    2010-01-01

    Specific palpation skills are required to identify and treat myofascial pain. The aim of this study was to develop a device that reflects absolute pressure values during simulated palpation, and to test the hypothesis that training through standardized manual palpation results in improved skills...... palpation training, experienced examiners improved palpatory skills related to P(peak) and RPD (i.e. performed closer to predetermined guidelines and with reduced inter-examiner variation), while inexperienced examiners only improved RPD (p

  13. Hip adductor muscle function in forward skating.

    Science.gov (United States)

    Chang, Ryan; Turcotte, Rene; Pearsall, David

    2009-09-01

    Adductor strain injuries are prevalent in ice hockey. It has long been speculated that adductor muscular strains may be caused by repeated eccentric contractions which decelerate the leg during a stride. The purpose of this study was to investigate the relationship of skating speed with muscle activity and lower limb kinematics, with a particular focus on the role of the hip adductors. Seven collegiate ice hockey players consented to participate. Surface electromyography (EMG) and kinematics of the lower extremities were measured at three skating velocities 3.33 m/s (slow), 5.00 m/s (medium) and 6.66 m/s (fast). The adductor magnus muscle exhibited disproportionately larger increases in peak muscle activation and significantly prolonged activation with increased speed. Stride rate and stride length also increased significantly with skating velocity, in contrast, hip, knee and ankle total ranges of motion did not. To accommodate for the increased stride rate with higher skating speeds, the rate of hip abduction increased significantly in concert with activations of adductor magnus indicating a substantial eccentric contraction. In conclusion, these findings highlight the functional importance of the adductor muscle group and hip abduction-adduction in skating performance as well as indirectly support the notion that groin strain injury potential increases with skating speed.

  14. Muscle enzyme release does not predict muscle function impairment after triathlon.

    Science.gov (United States)

    Margaritis, I; Tessier, F; Verdera, F; Bermon, S; Marconnet, P

    1999-06-01

    We sought to determine the effects of a long distance triathlon (4 km swim, 120 km bike-ride, and 30 km run) on the four-day kinetics of the biochemical markers of muscle damage, and whether they were quantitatively linked with muscle function impairment and soreness. Data were collected from 2 days before until 4 days after the completion of the race. Twelve triathletes performed the triathlon and five did not. Maximal voluntary contraction (MVC), muscle soreness (DOMS) and total serum CK, CK-MB, LDH, AST and ALT activities were assessed. Significant changes after triathlon completion were found for all muscle damage indirect markers over time (p triathlon. Long distance triathlon race caused muscle damage, but extent, as well as muscle recovery cannot be evaluated by the magnitude of changes in serum enzyme activities. Muscle enzyme release cannot be used to predict the magnitude of the muscle function impairment caused by muscle damage.

  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. Correlation between maximum voluntary contraction and endurance measured by digital palpation and manometry: An observational study

    Directory of Open Access Journals (Sweden)

    Fátima Faní Fitz

    Full Text Available Summary Introduction: Digital palpation and manometry are methods that can provide information regarding maximum voluntary contraction (MVC and endurance of the pelvic floor muscles (PFM, and a strong correlation between these variables can be expected. Objective: To investigate the correlation between MVC and endurance, measured by digital palpation and manometry. Method: Forty-two women, with mean age of 58.1 years (±10.2, and predominant symptoms of stress urinary incontinence (SUI, were included. Examination was firstly conducted by digital palpation and subsequently using a Peritron manometer. MVC was measured using a 0-5 score, based on the Oxford Grading Scale. Endurance was assessed based on the PERFECT scheme. Results: We found a significant positive correlation between the MVC measured by digital palpation and the peak manometric pressure (r=0.579, p<0.001, and between the measurements of the endurance by Peritron manometer and the PERFECT assessment scheme (r=0.559, P<0.001. Conclusion: Our results revealed a positive and significant correlation between the capacity and maintenance of PFM contraction using digital and manometer evaluations in women with predominant symptoms of SUI.

  17. 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.

  18. Bovine Reproductive Palpation Training: Does the Cow Make a Difference?

    Science.gov (United States)

    French, Hilari M; Dascanio, John J; Gilbert, Gregory E; Robinson, James Q

    2018-01-01

    Gaining experience and dexterity for trans-rectal cattle palpation requires substantial training. Simulation allows students to perform palpation without risks and to obtain feedback, but many believe live cattle palpation is essential. Limited research exists on the proper training method for live animal trans-rectal palpation. This study compared student improvement in laboratory palpation skills when assigned to the same cows versus choosing a cow at random. The hypothesis for the study was that students assigned the same cow, as compared to students choosing a cow at random, would be more accurate at palpation, would learn what structures are present on the ovaries and what size the reproductive tract measures, and would be able to follow the cyclicity of the cow. Cervical diameter, uterine tone, diameter of left and right uterine horns, and ovarian structures were recorded over time. Responses were compared to laboratory instructors' responses and Z-tests for proportions were used to test the differences in percentage correct at each time point for each palpation exercise. Overall the experiment showed that assigning students to certain cows will not improve their trans-rectal palpation training. However, asking students to identify specific landmarks with quantitative measurements did allow for more productive laboratory time and engaged students. The results of the present study also suggest that if there is limited time available for palpation instruction, choosing cows with behavior allowing easy handling is important to the educational process.

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

    Science.gov (United States)

    2014-12-19

    synergistic effect of treadmill running on stem -cell transplantation to heal injured skeletal muscle. Tissue Eng Part A 2010, 16(3):839–849. 20. Brutsaert...U:::-’ 0:: 0 Uninjured Injured Figure 7 c E 14 w cu12 • SED * (/) Cll < 10 ~ ~ 8 c 6 Cll Cl 4 z ..!!! ::> 0 2 0::: u 0 Uninjured Injured

  20. Stem Cell Antigen-1 in Skeletal Muscle Function

    OpenAIRE

    Bernstein, Harold S.; Samad, Tahmina; Cholsiripunlert, Sompob; Khalifian, Saami; Gong, Wenhui; Ritner, Carissa; Aurigui, Julian; Ling, Vivian; Wilschut, Karlijn J.; Bennett, Stephen; Hoffman, Julien; Oishi, Peter

    2013-01-01

    Stem cell antigen-1 (Sca-1) is a member of the Ly-6 multigene family encoding highly homologous, glycosyl-phosphatidylinositol-anchored membrane proteins. Sca-1 is expressed on muscle-derived stem cells and myogenic precursors recruited to sites of muscle injury. We previously reported that inhibition of Sca-1 expression stimulated myoblast proliferation in vitro and regulated the tempo of muscle repair in vivo. Despite its function in myoblast expansion during muscle repair, a role for Sca-1...

  1. Skeletal muscle aging: stem cell function and tissue homeostasis

    OpenAIRE

    Victor, Pedro Sousa

    2012-01-01

    Muscle aging, in particular, is characterized by the reduction of tissue mass and function, which are particularly prominent in geriatric individuals undergoing sarcopenia. The age-associated muscle wasting is also associated with a decline in regenerative ability and a reduction in resident muscle stem cell (satellite cell) number and function. Although sarcopenia is one of the major contributors to the general loss of physiological function, the mechanisms involved in age-related loss of mu...

  2. Palpation thyroiditis following subtotal parathyroidectomy for hyperparathyroidism

    Directory of Open Access Journals (Sweden)

    Elizabeth M Madill

    2016-07-01

    Full Text Available Thyrotoxicosis is an under-recognised but clinically important complication of parathyroidectomy. We report a case of a 37-year-old man with tertiary hyperparathyroidism who initially developed unexplained anxiety, diaphoresis, tachycardia, tremor and hyperreflexia one day after subtotal parathyroidectomy. Thyroid biochemistry revealed suppressed thyroid stimulating hormone and elevated serum free T4 and free T3 levels. Technetium-99m scintigraphy scan confirmed diffusely decreased radiotracer uptake consistent with thyroiditis. The patient was diagnosed with thyrotoxicosis resulting from palpation thyroiditis. Administration of oral beta-adrenergic antagonists alleviated his symptoms and there was biochemical evidence of resolution fourteen days later. This case illustrates the need to counsel patients about thyroiditis as one of the potential risks of parathyroid surgery. It also emphasises the need for biochemical surveillance in patients with unexplained symptoms in the post-operative period and may help to minimise further invasive investigations for diagnostic clarification.

  3. 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.

  4. L-acetylcarnitine enhances functional muscle re-innervation.

    Science.gov (United States)

    Pettorossi, V E; Brunetti, O; Carobi, C; Della Torre, G; Grassi, S

    1991-01-01

    The efficacy of L-acetylcarnitine and L-carnitine treatment on motor re-innervation was analyzed by evaluating different muscular parameters describing functional muscle recovery after denervation and re-innervation. The results show that L-acetylcarnitine markedly enhances functional muscle re-innervation, which on the contrary is unaffected by L-carnitine. The medial gastrocnemius muscle was denervated by cutting the nerve at the muscle entry point. After 20 days the sectioned nerve was resutured into the medial gastrocnemius muscle, and the extent of re-innervation was monitored 45 days later. L-acetylcarnitine-treated animals show significantly higher twitch and tetanic tensions of re-innervated muscle. Furthermore the results, obtained by analysing the twitch time to peak and tetanic contraction-relaxation times, suggest that L-acetylcarnitine mostly affects the functional re-innervation of slow motor units. The possible mechanisms by which L-acetylcarnitine facilitates such motor and nerve recovery are discussed.

  5. Stem cell antigen-1 in skeletal muscle function.

    Science.gov (United States)

    Bernstein, Harold S; Samad, Tahmina; Cholsiripunlert, Sompob; Khalifian, Saami; Gong, Wenhui; Ritner, Carissa; Aurigui, Julian; Ling, Vivian; Wilschut, Karlijn J; Bennett, Stephen; Hoffman, Julien; Oishi, Peter

    2013-08-15

    Stem cell antigen-1 (Sca-1) is a member of the Ly-6 multigene family encoding highly homologous, glycosyl-phosphatidylinositol-anchored membrane proteins. Sca-1 is expressed on muscle-derived stem cells and myogenic precursors recruited to sites of muscle injury. We previously reported that inhibition of Sca-1 expression stimulated myoblast proliferation in vitro and regulated the tempo of muscle repair in vivo. Despite its function in myoblast expansion during muscle repair, a role for Sca-1 in normal, post-natal muscle has not been thoroughly investigated. We systematically compared Sca-1-/- (KO) and Sca-1+/+ (WT) mice and hindlimb muscles to elucidate the tissue, contractile, and functional effects of Sca-1 in young and aging animals. Comparison of muscle volume, fibrosis, myofiber cross-sectional area, and Pax7+ myoblast number showed little differences between ages or genotypes. Exercise protocols, however, demonstrated decreased stamina in KO versus WT mice, with young KO mice achieving results similar to aging WT animals. In addition, KO mice did not improve with practice, while WT animals demonstrated conditioning over time. Surprisingly, myomechanical analysis of isolated muscles showed that KO young muscle generated more force and experienced less fatigue. However, KO muscle also demonstrated incomplete relaxation with fatigue. These findings suggest that Sca-1 is necessary for muscle conditioning with exercise, and that deficient conditioning in Sca-1 KO animals becomes more pronounced with age.

  6. Function of the epaxial muscles during trotting.

    Science.gov (United States)

    Schilling, Nadja; Carrier, David R

    2009-04-01

    In mammals, the epaxial muscles are believed to stabilize the trunk during walking and trotting because the timing of their activity is not appropriate to produce bending of the trunk. To test whether this is indeed the case, we recorded the activity of the m. multifidus lumborum and the m. longissimus thoracis et lumborum at three different sites along the trunk (T13, L3, L6) as we manipulated the moments acting on the trunk and the pelvis in dogs trotting on a treadmill. Confirming results of previous studies, both muscles exhibited a biphasic and bilateral activity. The higher burst was associated with the second half of ipsilateral hindlimb stance phase, the smaller burst occurred during the second half of ipsilateral hindlimb swing phase. The asymmetry was noticeably larger in the m. longissimus thoracis et lumborum than in the m. multifidus lumborum. Although our manipulations of the inertia of the trunk produced results that are consistent with previous studies indicating that the epaxial muscles stabilize the trunk against accelerations in the sagittal plane, the responses of the epaxial muscles to manipulations of trunk inertia were small compared with their responses when moments produced by the extrinsic muscles of the hindlimb were manipulated. Our results indicate that the multifidus and longissimus muscles primarily stabilize the pelvis against (1) vertical components of hindlimb retractor muscles and (2) horizontal components of the hindlimb protractor and retractor muscles. Consistent with this, stronger effects of the manipulations were observed in the posterior sampling sites.

  7. 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...

  8. 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

  9. Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, William G., E-mail: bp1@bu.edu [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States); Hindson, David F. [Department of Radiology, Boston Medical Center, Boston, Massachusetts (United States); Langmore, Susan E. [Department of Otolaryngology, Boston Medical Center, Boston, Massachusetts (United States); Speech and Hearing Sciences, Boston University, Boston, Massachusetts (United States); Zumwalt, Ann C. [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States)

    2013-03-01

    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

  10. Adiposity, muscle mass and muscle strength in relation to functional decline in older persons.

    NARCIS (Netherlands)

    Schaap, L.A.; Koster, A.; Visser, M.

    2013-01-01

    Aging is associated with changes in body composition and muscle strength. This review aimed to determine the relation between different body composition measures and muscle strength measures and functional decline in older men and women. By use of relevant databases (PubMed, Embase, and CINAHL) and

  11. Functional morphology of the radialis muscle in shark tails.

    Science.gov (United States)

    Flammang, Brooke E

    2010-03-01

    The functional morphology of intrinsic caudal musculature in sharks has not been studied previously, though the kinematics and function of body musculature have been the focus of a great deal of research. In the tail, ventral to the axial myomeres, there is a thin strip of red muscle with fibers angled dorsoposteriorly, known as the radialis. This research gives the first anatomical description of the radialis muscle in sharks, and addresses the hypothesis that the radialis muscle provides postural stiffening in the tail of live swimming sharks. The radialis muscle fibers insert onto the deepest layers of the stratum compactum, the more superior layers of which are orthogonally arrayed and connect to the epidermis. The two deepest layers of the stratum compactum insert onto the proximal ends of the ceratotrichia of the caudal fin. This anatomical arrangement exists in sharks and is modified in rays, but was not found in skates or chimaeras. Electromyography of the caudal muscles of dogfish swimming steadily at 0.25 and 0.5 body lengths per second (Ls(-1)) exhibited a pattern of anterior to posterior activation of the radialis muscle, followed by activation of red axial muscle in the more anteriorly located ipsilateral myomeres of the caudal peduncle; at 0.75 L s(-1), only the anterior portion of the radialis and white axial muscle of the contralateral peduncular myomeres were active. Activity of the radialis muscle occurred during periods of the greatest drag incurred by the tail during the tail beat and preceded the activity of more anteriorly located axial myomeres. This nonconformity to the typical anterior to posterior wave of muscle activation in fish swimming, in combination with anatomical positioning of the radialis muscles and stratum compactum, suggests that radialis activity may have a postural function to stiffen the fin, and does not function as a typical myotomal muscle.

  12. Calcium ion in skeletal muscle: its crucial role for muscle function, plasticity, and disease

    DEFF Research Database (Denmark)

    Berchtold, M W; Brinkmeier, H; Müntener, M

    2000-01-01

    in the sarcoplasmic reticulum. In addition, a multitude of Ca(2+)-binding proteins is present in muscle tissue including parvalbumin, calmodulin, S100 proteins, annexins, sorcin, myosin light chains, beta-actinin, calcineurin, and calpain. These Ca(2+)-binding proteins may either exert an important role in Ca(2......Mammalian skeletal muscle shows an enormous variability in its functional features such as rate of force production, resistance to fatigue, and energy metabolism, with a wide spectrum from slow aerobic to fast anaerobic physiology. In addition, skeletal muscle exhibits high plasticity that is based...... on the potential of the muscle fibers to undergo changes of their cytoarchitecture and composition of specific muscle protein isoforms. Adaptive changes of the muscle fibers occur in response to a variety of stimuli such as, e.g., growth and differentition factors, hormones, nerve signals, or exercise...

  13. Spot light on skeletal muscles: optogenetic stimulation to understand and restore skeletal muscle function.

    Science.gov (United States)

    van Bremen, Tobias; Send, Thorsten; Sasse, Philipp; Bruegmann, Tobias

    2017-08-01

    Damage of peripheral nerves results in paralysis of skeletal muscle. Currently, the only treatment option to restore proper function is electrical stimulation of the innervating nerve or of the skeletal muscles directly. However this approach has low spatial and temporal precision leading to co-activation of antagonistic muscles and lacks cell-type selectivity resulting in pain or discomfort by stimulation of sensible nerves. In contrast to electrical stimulation, optogenetic methods enable spatially confined and cell-type selective stimulation of cells expressing the light sensitive channel Channelrhodopsin-2 with precise temporal control over the membrane potential. Herein we summarize the current knowledge about the use of this technology to control skeletal muscle function with the focus on the direct, non-neuronal stimulation of muscle fibers. The high temporal flexibility of using light pulses allows new stimulation patterns to investigate skeletal muscle physiology. Furthermore, the high spatial precision of focused illumination was shown to be beneficial for selective stimulation of distinct nearby muscle groups. Finally, the cell-type specific expression of the light-sensitive effector proteins in muscle fibers will allow pain-free stimulation and open new options for clinical treatments. Therefore, we believe that direct optogenetic stimulation of skeletal muscles is a very potent method for basic scientists that also harbors several distinct advantages over electrical stimulation to be considered for clinical use in the future.

  14. Function of skeletal muscle tissue formed after myoblast transplantation into irradiated mouse muscles.

    Science.gov (United States)

    Wernig, A; Zweyer, M; Irintchev, A

    2000-01-15

    1. Pretreatment of muscles with ionising radiation enhances tissue formation by transplanted myoblasts but little is known about the effects on muscle function. We implanted myoblasts from an expanded, male-donor-derived, culture (i28) into X-ray irradiated (16 Gy) or irradiated and damaged soleus muscles of female syngeneic mice (Balb/c). Three to 6 months later the isometric contractile properties of the muscles were studied in vitro, and donor nuclei were visualised in muscle sections with a Y chromosome-specific DNA probe. 2. Irradiated sham-injected muscles had smaller masses than untreated solei and produced less twitch and tetanic force (all by about 18 %). Injection of 106 myoblasts abolished these deficiencies and innervation appeared normal. 3. Cryodamage of irradiated solei produced muscle remnants with few (1-50) or no fibres. Additional myoblast implantation led to formation of large muscles (25 % above normal) containing numerous small-diameter fibres. Upon direct electrical stimulation, these muscles produced considerable twitch (53 % of normal) and tetanic forces (35 % of normal) but innervation was insufficient as indicated by weak nerve-evoked contractions and elevated ACh sensitivity. 4. In control experiments on irradiated muscles, reinnervation was found to be less complete after botulinum toxin paralysis than after nerve crush indicating that proliferative arrest of irradiated Schwann cells may account for the observed innervation deficits. 5. Irradiation appears to be an effective pretreatment for improving myoblast transplantation. The injected cells can even produce organised contractile tissue replacing whole muscle. However, impaired nerve regeneration limits the functional performance of the new muscle.

  15. Effect of pelvic floor muscle exercises on pulmonary function

    OpenAIRE

    Han, DongWook; Ha, Misook

    2015-01-01

    [Purpose] This study aimed to determine the correlation between pelvic floor muscle strength and pulmonary function. In particular, we examined whether pelvic floor muscle exercises can improve pulmonary function. [Subjects] Thirty female college students aged 19?21 with no history of nervous or musculoskeletal system injury were randomly divided into experimental and control groups. [Methods] For the pulmonary function test, spirometry items included forced vital capacity and maximal volunta...

  16. Cryopreservation of human skeletal muscle impairs mitochondrial function

    DEFF Research Database (Denmark)

    Larsen, Steen; Wright-Paradis, C; Gnaiger, E

    2012-01-01

    functionality after long term cryopreservation (1 year). Skeletal muscle samples were preserved in dimethyl sulfoxide (DMSO) for later analysis. Human skeletal muscle fibres were thawed and permeabilised with saponin, and mitochondrial respiration was measured by high-resolution respirometry. The capacity...

  17. Pelvic floor muscle function in women with pelvic floor dysfunction

    DEFF Research Database (Denmark)

    Tibaek, Sigrid; Dehlendorff, Christian

    2014-01-01

    The objectives of this study were to investigate the level of pelvic floor muscle (PFM) function in women with pelvic floor dysfunction (PFD) referred by gynaecologists and urologists for in-hospital pelvic floor muscle training (PFMT), and to identity associated factors for a low level of PFM...

  18. Muscle function and origin of pain in fibromyalgia

    DEFF Research Database (Denmark)

    Bennett, R M; Jacobsen, Søren

    1994-01-01

    It may be concluded that both peripheral and central mechanisms may operate in the pathophysiology of both impaired muscle function and pain in FM. These mechanisms may in part be attributable to physical deconditioning and disuse of muscle secondary to the characteristic pain and fatigue so ofte...

  19. Communication between functional and denervated muscles using radiofrequency.

    Science.gov (United States)

    Jacob, Doreen K; Stefko, Susan Tonya; Hackworth, Steven A; Lovell, Michael R; Mickle, Marlin H

    2006-05-01

    This article focuses on establishing communication between a functional muscle and a denervated muscle using a radiofrequency communications link. The ultimate objective of the project is to restore the eye blink in patients with facial nerve paralysis. Two sets of experiments were conducted using the gastrocnemius leg muscles of Sprague-Dawley rats. In the initial tests, varying magnitudes of voltages ranging from 0.85 to 2.5 V were applied directly to a denervated muscle to determine the voltage required to produce visible contraction. The second set of experiments was then conducted to determine the voltage output from an in vivo muscle contraction that could be sensed and used to coordinate a signal for actuation of a muscle in a separate limb. After designing the appropriate external communication circuitry, a third experiment was performed to verify that a signal between a functional and a denervated muscle can be generated and used as a stimulus. Voltages below 2 V at a 10-millisecond pulse width elicited a gentle, controlled contraction of the denervated muscle in vivo. It was also observed that with longer pulse widths, higher stimulation voltages were required to produce sufficient contractions. It is possible to detect contraction of a muscle, use this to generate a signal to an external base station, and subsequently cause a separate, denervated muscle to contract in response to the signal. This demonstration in vivo of a signaling system for pacing of electrical stimulation of 1 muscle to spontaneous contraction of another, separate muscle, using radiofrequency communication without direct connection, may be used in numerous ways to overcome nerve damage.

  20. Pelvic floor muscle strength and sexual function in women

    Directory of Open Access Journals (Sweden)

    Cinara Sacomori

    Full Text Available Abstract Introduction : Pelvic floor (PF muscles react to sexual stimuli with increased local blood circulation and involuntary contractions during orgasm. The training of the PF musculature helps in the improvement of the female sexual function. Objective : To verify the association between PF muscle strength and sexual function in women, controlling age and parity. Method : Cross-sectional study based on associations. The study included women who attended a reference center in Florianópolis, Santa Catarina, for a uterine cancer smear test. The Functional Evaluation of the Pelvic Floor and the Female Sexual Function Index questionnaire were used. Statistical procedures included Mann-Whitney U tests, Spearman correlation and Poisson Regression Analysis, with p < .05. Results : The mean age of the women (n = 177 was 39.05 years (SD = 13.3. Regarding PF function, 53.7% of participants presented weak or not palpable PF muscle function. Women with "good" muscle function (able to maintain contraction under examiner's resistance had significantly better indexes of sexual desire, excitement, lubrication and orgasm than women with weak/poor function. We identified that 52.5% of the women presented sexual dysfunction. Women with "poor" PF function and aged over 50 years had, respectively, 1.36 (CI95% 1.01 - 1.82 and 1.77 (CI95% 1.41 - 2.23 higher prevalence of sexual dysfunction than women with "good" PF function. Conclusions : Adult women with better PF muscle function also presented better sexual function.

  1. Muscle Functions and Functional Performance among Older Persons with and without Low Back Pain

    Directory of Open Access Journals (Sweden)

    Nor Azizah Ishak

    2016-01-01

    Full Text Available This study aims to compare muscle functions and functional performances between older persons with and without low back pain (LBP and to determine the association between muscle functions and functional performances. This is a cross-sectional study, involving 95 older persons (age = 70.27±7.26 years. Anthropometric characteristics, muscle functions, and functional performances were measured. Data were analyzed using ANOVA, Pearson’s correlation, and multiple linear regression. The functional performances showed no significant differences (females LBP versus non-LBP, males LBP versus non-LBP (p<0.05. For muscle functions, significant differences were found (females LBP versus non-LBP for abdominal muscle strength (p=0.006 and back muscle strength (p=0.07. In the LBP group, significant correlations were found between back and abdominal muscle strength and hand grip strength (r=0.377 and r=0.396, resp., multifidus control and lower limb function (r=0.363 in females, and back muscle strength and lower limb function (r=0.393 in males (all p<0.05. Regression analysis showed that abdominal and back muscle strengths were significant predictors of hand grip strength (p=0.041 and p=0.049, resp., and multifidus control was a significant predictor of lower limb function in females (p=0.047. This study demonstrates that older women with LBP exhibit poorer muscle functions compared to older women without LBP.

  2. Growth factors, muscle function, and doping.

    Science.gov (United States)

    Goldspink, Geoffrey; Wessner, Barbara; Tschan, Harald; Bachl, Norbert

    2010-03-01

    This article discusses the inevitable use of growth factors for enhancing muscle strength and athletic performance. Much effort has been expended on developing a treatment of muscle wasting associated with a range of diseases and aging. Frailty in the aging population is a major socioeconomic and medical problem. Emerging molecular techniques have made it possible to gain a better understanding of the growth factor genes and how they are activated by physical activity. The ways that misuse of growth factors may be detected and verified in athletes and future challenges for detecting manipulation of signaling pathways are discussed. Copyright 2010. Published by Elsevier Inc.

  3. Muscle glycogen and cell function--Location, location, location.

    Science.gov (United States)

    Ørtenblad, N; Nielsen, J

    2015-12-01

    The importance of glycogen, as a fuel during exercise, is a fundamental concept in exercise physiology. The use of electron microscopy has revealed that glycogen is not evenly distributed in skeletal muscle fibers, but rather localized in distinct pools. In this review, we present the available evidence regarding the subcellular localization of glycogen in skeletal muscle and discuss this from the perspective of skeletal muscle fiber function. The distribution of glycogen in the defined pools within the skeletal muscle varies depending on exercise intensity, fiber phenotype, training status, and immobilization. Furthermore, these defined pools may serve specific functions in the cell. Specifically, reduced levels of these pools of glycogen are associated with reduced SR Ca(2+) release, muscle relaxation rate, and membrane excitability. Collectively, the available literature strongly demonstrates that the subcellular localization of glycogen has to be considered to fully understand the role of glycogen metabolism and signaling in skeletal muscle function. Here, we propose that the effect of low muscle glycogen on excitation-contraction coupling may serve as a built-in mechanism, which links the energetic state of the muscle fiber to energy utilization. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Muscle glycogen and cell function - Location, location, location

    DEFF Research Database (Denmark)

    Ørtenblad, N; Nielsen, Joachim

    2015-01-01

    The importance of glycogen, as a fuel during exercise, is a fundamental concept in exercise physiology. The use of electron microscopy has revealed that glycogen is not evenly distributed in skeletal muscle fibers, but rather localized in distinct pools. In this review, we present the available...... evidence regarding the subcellular localization of glycogen in skeletal muscle and discuss this from the perspective of skeletal muscle fiber function. The distribution of glycogen in the defined pools within the skeletal muscle varies depending on exercise intensity, fiber phenotype, training status......, and immobilization. Furthermore, these defined pools may serve specific functions in the cell. Specifically, reduced levels of these pools of glycogen are associated with reduced SR Ca(2+) release, muscle relaxation rate, and membrane excitability. Collectively, the available literature strongly demonstrates...

  5. Functional Echomyography of the human denervated muscle: first results

    Directory of Open Access Journals (Sweden)

    Riccardo Zanato

    2011-03-01

    . The very high energy needed to stimulate the denervated muscles according to the Vienna home-based Functional Electrical Stimulation (h-b FES strategy demonstrates that the explored muscles are denervated. This pilot study confirms the usefulness of Functional EchoMyography in the follow-up and the positive effects of h-b FES of denervated/reinnervating muscles.

  6. Transient impairments in single muscle fibre contractile function after prolonged cycling in elite endurance athletes

    DEFF Research Database (Denmark)

    Hvid, L G; Gejl, Kasper Degn; Bech, R D

    2013-01-01

    Prolonged muscle activity impairs whole-muscle performance and function. However, little is known about the effects of prolonged muscle activity on the contractile function of human single muscle fibres. The purpose of this study was to investigate the effects of prolonged exercise and subsequent...... recovery on the contractile function of single muscle fibres obtained from elite athletes....

  7. Fragility fracture risk and skeletal muscle function.

    Science.gov (United States)

    Pérez-López, F R; Ara, I

    2016-01-01

    Low-intensity fractures are closely related with age-related musculoskeletal disorders, including osteoporosis, muscle dysfunction and sarcopenia, age-related chronic diseases, and pharmacological treatments. During the last years, a huge amount of information and recommendations has been released in relation to bone metabolism and mineral content. Muscle dysfunction and sarcopenia are highly prevalent during the second half of life, especially in older subjects. The development of sarcopenia may be slowed through healthy lifestyle changes, which include adequate dietary protein, vitamin D and mineral intakes, and regular physical activity. Prevention of falls should be integral, including correction in major involved factors in order to reduce fragility fracture, improve quality of life and appropriately focus clinical and economic resources. Therefore, to obtain better results a global approach is needed to prevent age-related fractures in frail patients that is not only centered on bone metabolism and antiresorptive drugs.

  8. Lower limb asymmetry in mechanical muscle function

    DEFF Research Database (Denmark)

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

    2015-01-01

    .05), and the final phase of the SJ (P AI in the CMJ concentric phase (r = 0.57, P Future research is required to assess the role of the CMJ and SJ phase-specific kinetic impulse AI......-R). Elite alpine skiers with ACL-R (n = 9; 26.2 ± 11.8 months post-op) and uninjured skiers (n = 9) participated in neuromuscular screening. Vertical ground reaction force during the CMJ and SJ was assessed using dual force plate methodology to obtain phase-specific bilateral asymmetry indices (AIs......) 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 AI in the CMJ concentric phase (P 

  9. Physical function and muscle strength in sporadic inclusion body myositis

    DEFF Research Database (Denmark)

    Jørgensen, Anders N; Aagaard, Per; Nielsen, Jakob L

    2017-01-01

    INTRODUCTION: In this study, self-reported physical function, functional capacity, and isolated muscle function were investigated in sporadic inclusion body myositis (sIBM) patients. METHODS: The 36-item Short Form (SF-36) Health Survey and 2-min walk test (2MWT), timed up & go test (TUG), and 30-s...

  10. TAK1 regulates skeletal muscle mass and mitochondrial function

    Science.gov (United States)

    Hindi, Sajedah M.; Sato, Shuichi; Xiong, Guangyan; Bohnert, Kyle R.; Gibb, Andrew A.; Gallot, Yann S.; McMillan, Joseph D.; Hill, Bradford G.

    2018-01-01

    Skeletal muscle mass is regulated by a complex array of signaling pathways. TGF-β–activated kinase 1 (TAK1) is an important signaling protein, which regulates context-dependent activation of multiple intracellular pathways. However, the role of TAK1 in the regulation of skeletal muscle mass remains unknown. Here, we report that inducible inactivation of TAK1 causes severe muscle wasting, leading to kyphosis, in both young and adult mice.. Inactivation of TAK1 inhibits protein synthesis and induces proteolysis, potentially through upregulating the activity of the ubiquitin-proteasome system and autophagy. Phosphorylation and enzymatic activity of AMPK are increased, whereas levels of phosphorylated mTOR and p38 MAPK are diminished upon inducible inactivation of TAK1 in skeletal muscle. In addition, targeted inactivation of TAK1 leads to the accumulation of dysfunctional mitochondria and oxidative stress in skeletal muscle of adult mice. Inhibition of TAK1 does not attenuate denervation-induced muscle wasting in adult mice. Finally, TAK1 activity is highly upregulated during overload-induced skeletal muscle growth, and inactivation of TAK1 prevents myofiber hypertrophy in response to functional overload. Overall, our study demonstrates that TAK1 is a key regulator of skeletal muscle mass and oxidative metabolism. PMID:29415881

  11. The Effect of Statins on Skeletal Muscle Function

    Science.gov (United States)

    Parker, Beth A.; Capizzi, Jeffrey A.; Grimaldi, Adam S.; Clarkson, Priscilla M.; Cole, Stephanie M.; Keadle, Justin; Chipkin, Stuart; Pescatello, Linda S.; Simpson, Kathleen; White, C. Michael; Thompson, Paul D.

    2015-01-01

    Background Many clinicians believe that statins cause muscle pain, but this has not been observed in clinical trials and the effect of statins on muscle performance has not been carefully studied. Methods and Results The Effect of STatins On Skeletal Muscle Function and Performance (STOMP) study assessed symptoms and measured creatine kinase (CK), exercise capacity, and muscle strength before and after atorvastatin 80 mg or placebo were administered for 6 months to 420 healthy, statin-naive subjects. No individual CK value exceeded 10 times normal, but average CK increased 20.8 ± 141.1 U/L (pmuscle strength or exercise capacity with atorvastatin, but more atorvastatin than placebo subjects developed myalgia (19 vs 10; p = 0.05). Myalgic subjects on atorvastatin or placebo decreased muscle strength in 5 of 14 and 4 of 14 variables respectively (p = 0.69). Conclusions These results indicate that high-dose atorvastatin for 6 months does not decrease average muscle strength or exercise performance in healthy, previously untreated subjects. Nevertheless, this blinded, controlled trial confirms the undocumented impression that statins increase muscle complaints. Atorvastatin also increased average CK suggesting that statins produce mild muscle injury even among asymptomatic subjects. This increase in CK should prompt studies examining the effects of more prolonged, high-dose statin treatment on muscular performance. Clinical Trial Registration Information: www.clinicaltrials.gov; Identifier: NCT00609063. PMID:23183941

  12. Resistance training, insulin sensitivity and muscle function in the elderly

    DEFF Research Database (Denmark)

    Dela, Flemming; Kjaer, Michael

    2006-01-01

    Ageing is associated with a loss in both muscle mass and in the metabolic quality of skeletal muscle. This leads to sarcopenia and reduced daily function, as well as to an increased risk for development of insulin resistance and type 2 diabetes. A major part, but not all, of these changes......, and likewise to improve muscle strength in both elderly healthy individuals and in elderly individuals with chronic disease. The increased strength is coupled to improved function and a decreased risk for fall injuries and fractures. Elderly individuals have preserved the capacity to improve muscle strength...... are associated with an age-related decrease in the physical activity level and can be counteracted by increased physical activity of a resistive nature. Strength training has been shown to improve insulin-stimulated glucose uptake in both healthy elderly individuals and patients with manifest diabetes...

  13. A three-dimensional muscle activity imaging technique for assessing pelvic muscle function

    Science.gov (United States)

    Zhang, Yingchun; Wang, Dan; Timm, Gerald W.

    2010-11-01

    A novel multi-channel surface electromyography (EMG)-based three-dimensional muscle activity imaging (MAI) technique has been developed by combining the bioelectrical source reconstruction approach and subject-specific finite element modeling approach. Internal muscle activities are modeled by a current density distribution and estimated from the intra-vaginal surface EMG signals with the aid of a weighted minimum norm estimation algorithm. The MAI technique was employed to minimally invasively reconstruct electrical activity in the pelvic floor muscles and urethral sphincter from multi-channel intra-vaginal surface EMG recordings. A series of computer simulations were conducted to evaluate the performance of the present MAI technique. With appropriate numerical modeling and inverse estimation techniques, we have demonstrated the capability of the MAI technique to accurately reconstruct internal muscle activities from surface EMG recordings. This MAI technique combined with traditional EMG signal analysis techniques is being used to study etiologic factors associated with stress urinary incontinence in women by correlating functional status of muscles characterized from the intra-vaginal surface EMG measurements with the specific pelvic muscle groups that generated these signals. The developed MAI technique described herein holds promise for eliminating the need to place needle electrodes into muscles to obtain accurate EMG recordings in some clinical applications.

  14. Sex steroids do not affect muscle weight, oxidative metabolism or cytosolic androgen reception binding of functionally overloaded rat Plantaris muscles

    Science.gov (United States)

    Max, S. R.; Rance, N.

    1983-01-01

    The effects of sex steroids on muscle weight and oxidative capacity of rat planaris muscles subjected to functional overload by removal of synergistic muscles were investigated. Ten weeks after bilateral synergist removal, plantaris muscles were significantly hypertrophic compared with unoperated controls. After this period, the ability of the muscles to oxide three substrates of oxidative metabolism was assessed. Experimental procedures are discussed and results are presented herein. Results suggest a lack of beneficial effect of sex hormone status on the process of hypertrophy and on biochemical changes in overloaded muscle. Such findings are not consistent with the idea of synergistic effects of sex steroids and muscle usage.

  15. Comparison of the functionality of pelvic floor muscles in women who practice the Pilates method and sedentary women: a pilot study.

    Science.gov (United States)

    Ferla, Lia; Paiva, Luciana Laureano; Darki, Caroline; Vieira, Adriane

    2016-01-01

    The Pilates method is a form of physical exercise that improves the control of the core muscles, improving the conditioning of all the muscle groups that comprise the core, including the pelvic floor muscles (PFM). Thus, this study had the goal of verifying the existence of differences in the functioning of the PFM in women who practice the Pilates method and sedentary women. This was an observational, cross-sectional pilot study. A sample size calculation was performed using preliminary data and it determined that the sample should have at least 24 individuals in each group. The participants were 60 women aged 20 to 40 years; 30 women practiced the Pilates method (PMG) and 30 were sedentary (SG). An anamnesis file was used to collect personal data and assess the knowledge and perception of the PFM. The Perina perineometer and vaginal palpation were used to determine the functionality of the PFM. There was no significant difference between the PMG and the SG in any of the variables analyzed. We concluded that the functionality of the PFM in younger women who practice the Pilates method is not different from that of sedentary women.

  16. Vardenafil inhibiting parasympathetic function of tracheal smooth muscle.

    Science.gov (United States)

    Lee, Fei-Peng; Chao, Pin-Zhir; Wang, Hsing-Won

    2018-07-01

    Levitra, a phosphodiesterase-5 (PDE5) inhibitor, is the trade name of vardenafil. Nowadays, it is applied to treatment of erectile dysfunction. PDE5 inhibitors are employed to induce dilatation of the vascular smooth muscle. The effect of Levitra on impotency is well known; however, its effect on the tracheal smooth muscle has rarely been explored. When administered for sexual symptoms via oral intake or inhalation, Levitra might affect the trachea. This study assessed the effects of Levitra on isolated rat tracheal smooth muscle by examining its effect on resting tension of tracheal smooth muscle, contraction caused by 10 -6  M methacholine as a parasympathetic mimetic, and electrically induced tracheal smooth muscle contractions. The results showed that adding methacholine to the incubation medium caused the trachea to contract in a dose-dependent manner. Addition of Levitra at doses of 10 -5  M or above elicited a significant relaxation response to 10 -6  M methacholine-induced contraction. Levitra could inhibit electrical field stimulation-induced spike contraction. It alone had minimal effect on the basal tension of the trachea as the concentration increased. High concentrations of Levitra could inhibit parasympathetic function of the trachea. Levitra when administered via oral intake might reduce asthma attacks in impotent patients because it might inhibit parasympathetic function and reduce methacholine-induced contraction of the tracheal smooth muscle. Copyright © 2018. Published by Elsevier Taiwan LLC.

  17. Muscle MRI and functional outcome measures in Becker muscular dystrophy.

    Science.gov (United States)

    Barp, Andrea; Bello, Luca; Caumo, Luca; Campadello, Paola; Semplicini, Claudio; Lazzarotto, Annalisa; Sorarù, Gianni; Calore, Chiara; Rampado, Alessandro; Motta, Raffaella; Stramare, Roberto; Pegoraro, Elena

    2017-11-22

    Becker muscular dystrophy (BMD) is a neuromuscular disorder allelic to Duchenne muscular dystrophy (DMD), caused by in-frame mutations in the dystrophin gene, and characterized by a clinical progression that is both milder and more heterogeneous than DMD. Muscle magnetic resonance imaging (MRI) has been proposed as biomarker of disease progression in dystrophinopathies. Correlation with clinically meaningful outcome measures such as North Star Ambulatory Assessment (NSAA) and 6 minute walk test (6MWT) is paramount for biomarker qualification. In this study, 51 molecularly confirmed BMD patients (aged 7-69 years) underwent muscle MRI and were evaluated with functional measures (NSAA and 6MWT) at the time of the MRI, and subsequently after one year. We confirmed a pattern of fatty substitution involving mainly the hip extensors and most thigh muscles. Severity of muscle fatty substitution was significantly correlated with specific DMD mutations: in particular, patients with an isolated deletion of exon 48, or deletions bordering exon 51, showed milder involvement. Fat infiltration scores correlated with baseline functional measures, and predicted changes after 1 year. We conclude that in BMD, skeletal muscle MRI not only strongly correlates with motor function, but also helps in predicting functional deterioration within a 12-month time frame.

  18. Relationship of Lower Extremity Muscle Strength with Balance and Lower Extremity Functions in Elderly Women

    Directory of Open Access Journals (Sweden)

    Ferdi Başkurt

    2018-03-01

    Conclusions: Functional score, mobility and balance are related to lower extremity muscle strength in elderly women. Increasing muscle strength will reduce the risk of falls and increase independence.

  19. Neuropathic pain-like alterations in muscle nociceptor function associated with vibration-induced muscle pain.

    Science.gov (United States)

    Chen, Xiaojie; Green, Paul G; Levine, Jon D

    2010-11-01

    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 action potentials in response to sustained suprathreshold mechanical stimulation (average of 2635 action potentials with frequency of ∼44Hz during a 1min suprathreshold stimulus) much greater than that has been reported to be produced even by potent inflammatory mediators. While these high-firing nociceptors had lower mechanical thresholds than the remaining nociceptors, exposure to vibration had no effect on conduction velocity and did not induce spontaneous activity. Hyperactivity was not observed in any of 19 neurons from vibration-exposed rats pretreated with intrathecal antisense for the IL-6 receptor subunit gp130. Since vibration can injure peripheral nerves and IL-6 has been implicated in painful peripheral neuropathies, we suggest that the dramatic change in sensory neuron function and development of muscles pain, induced by exposure to vibration, reflects a neuropathic muscle pain syndrome. Copyright © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  20. Reproducibility and clinical utility of tendon palpation to detect patellar tendinopathy in young basketball players

    Science.gov (United States)

    Cook, J; Khan, K; Kiss, Z; Purdam, C; Griffiths, L

    2001-01-01

    Background—Palpation is an important clinical test for jumper's knee. Objectives—To (a) test the reproducibility of palpation tenderness, (b) evaluate the sensitivity and specificity of palpation in subjects with clinical symptoms of jumper's knee, and (c) determine whether tenderness to palpation may serve as a useful screening test for patellar tendinopathy. The yardstick for diagnosis of patellar tendinopathy was ultrasonographic abnormality. Methods—In 326 junior symptomatic and asymptomatic athletes' tendons, palpation was performed by a single examiner before ultrasonographic examination by a certified ultrasound radiologist. In 58 tendons, palpation was performed twice to test reliability. Tenderness to palpation was scored on a scale from 0 to 3 where 0 represented no pain, and 1, 2, and 3 represented mild, moderate, and severe tenderness respectively. Results—Patellar tendon palpation was a reliable examination for a single examiner (Pearson r = 0.82). In symptomatic tendons, the positive predictive value of palpation was 68%. As a screening examination in asymptomatic subjects, the positive predictive value of tendon palpation was 36–38%. Moderate and severe palpation tenderness were better predictors of ultrasonographic tendon pathology than absent or mild tenderness (ppatellar tendinopathy in a preparticipation examination. In symptomatic tendons, palpation is a moderately sensitive but not specific test. Mild tenderness in the patellar tendons in asymptomatic jumping athletes should be considered normal. Key Words: patellar tendon; ultrasound; palpation; reliability; athletes PMID:11157466

  1. The Promotion of a Functional Fibrosis in Skeletal Muscle with Volumetric Muscle Loss Injury Following the Transplantation of Muscle-ECM

    Science.gov (United States)

    2013-02-04

    Zou K, Boppart MD. Eccentric exercise facil- itates mesenchymal stem cell appearance in skeletal muscle. PLoS One 2012; 7:e29760. [40] Matziolis G...remaining muscle mass leading to additional improvements in functional capacity; how- ever, no study has explicitly studied these effects . The purpose of...muscles were isolated from donor Lewis rats. The tendon and fascia were removed and TA muscle decellularization was performed using an enzymatic and

  2. Association between preterm labour and pelvic floor muscle function.

    Science.gov (United States)

    Aran, Turhan; Pekgöz, Ipek; Bozkaya, Hasan; Osmanagaoglu, Mehmet A

    2018-03-23

    We hypothesised that the pressure on the cervix increases with advancing gestation and it may lead to a cervical shortening and cause preterm labour in women with weak pelvic floor muscles. The aim of this prospective study was to measure vaginal resting pressure and pelvic floor muscle strength in the first trimester of pregnancy and to investigate their effects on labour. A study was conducted on the pregnant women with a low risk for preterm birth. The pelvic floor muscle strength and vaginal resting pressure were assessed in 320 pregnant women at their first trimester with a vaginal pressure measurement device. Fifty-two pregnant women were hospitalised for tocolytic therapy because of spontaneous preterm labour. Thirty-two of them (10.2%) had a preterm delivery despite the tocolytic therapy. Both the vaginal resting pressure (p = .009, 95%CI: 0.8; 5.9) and the pelvic floor muscle strength (p = .01, 95%CI: 3.5; 13.1) were significantly lower in the women with a preterm labour. Impact statement What is already known on this subject? The pelvic floor muscles have an essential role in continence and provide support to the pelvic organs. They also have an impact on labour. The pelvic floor muscles should distend to allow the passage of the foetus during labour. The rotation and flexion of the foetal head is due to the pelvic floor resistance. The effect of a vaginal birth on the pelvic floor's function is readily understood. On the other hand, the effect of the pelvic floor muscle function on labour is still controversial. What do the results of this study add? This prospective study showed that there is a negative association between the pelvic floor muscle strength and preterm labour. This is the first clinical study indicating that weak pelvic floor muscles may cause a preterm labour. What are the implications of these findings for clinical practice and/or further research? Pelvic floor physical therapy may be an alternative preventive strategy to reduce

  3. Abdominal muscle function and incisional hernia: a systematic review.

    Science.gov (United States)

    Jensen, K K; Kjaer, M; Jorgensen, L N

    2014-08-01

    Although ventral incisional hernia (VIH) repair in patients is often evaluated in terms of hernia recurrence rate and health-related quality of life, there is no clear consensus regarding optimal operative treatment based on these parameters. It was proposed that health-related quality of life depends largely on abdominal muscle function (AMF), and the present review thus evaluates to what extent AMF is influenced by VIH and surgical repair. The PubMed and EMBASE databases were searched for articles following a systematic strategy for inclusion. A total of seven studies described AMF in relation to VIH. Five studies examined AMF using objective isokinetic dynamometers to determine muscle strength, and two studies examined AMF by clinical examination-based muscle tests. Both equipment-related and functional muscle tests exist for use in patients with VIH, but very few studies have evaluated AMF in VIH. There are no randomized controlled studies to describe the impact of VIH repair on AMF, and no optimal surgical treatment in relation to AMF after VIH repair can be advocated for at this time.

  4. Effects of aging on muscle mechanical function and muscle fiber morphology during short-term immobilization and subsequent retraining

    DEFF Research Database (Denmark)

    Hvid, Lars; Aagaard, Per; Justesen, Lene

    2010-01-01

    Very little attention has been given to the combined effects of aging and disuse as separate factors causing deterioration in muscle mechanical function. Thus the purpose of this study was to investigate the effects of 2 wk of immobilization followed by 4 wk of retraining on knee extensor muscle...... to the deleterious effects of short-term muscle disuse on muscle fiber size and rapid force capacity than YM. Furthermore, OM seems to require longer time to recover and regain rapid muscle force capacity, which may lead to a larger risk of falling in aged individuals after periods of short-term disuse....

  5. Caspase-12 ablation preserves muscle function in the mdx mouse

    Science.gov (United States)

    Moorwood, Catherine; Barton, Elisabeth R.

    2014-01-01

    Duchenne muscular dystrophy (DMD) is a devastating muscle wasting disease caused by mutations in dystrophin. Several downstream consequences of dystrophin deficiency are triggers of endoplasmic reticulum (ER) stress, including loss of calcium homeostasis, hypoxia and oxidative stress. During ER stress, misfolded proteins accumulate in the ER lumen and the unfolded protein response (UPR) is triggered, leading to adaptation or apoptosis. We hypothesized that ER stress is heightened in dystrophic muscles and contributes to the pathology of DMD. We observed increases in the ER stress markers BiP and cleaved caspase-4 in DMD patient biopsies, compared with controls, and an increase in multiple UPR pathways in muscles of the dystrophin-deficient mdx mouse. We then crossed mdx mice with mice null for caspase-12, the murine equivalent of human caspase-4, which are resistant to ER stress. We found that deleting caspase-12 preserved mdx muscle function, resulting in a 75% recovery of both specific force generation and resistance to eccentric contractions. The compensatory hypertrophy normally found in mdx muscles was normalized in the absence of caspase-12; this was found to be due to decreased fibre sizes, and not to a fibre type shift or a decrease in fibrosis. Fibre central nucleation was not significantly altered in the absence of caspase-12, but muscle fibre degeneration found in the mdx mouse was reduced almost to wild-type levels. In conclusion, we have identified heightened ER stress and abnormal UPR signalling as novel contributors to the dystrophic phenotype. Caspase-4 is therefore a potential therapeutic target for DMD. PMID:24879640

  6. Kinesiophobia, Pain, Muscle Functions, and Functional Performances among Older Persons with Low Back Pain

    Directory of Open Access Journals (Sweden)

    Nor Azizah Ishak

    2017-01-01

    Full Text Available Objectives. This study aims (1 to determine the association between kinesiophobia and pain, muscle functions, and functional performances and (2 to determine whether kinesiophobia predicts pain, muscle functions, and functional performance among older persons with low back pain (LBP. Methods. This is a correlational study, involving 63 institutionalized older persons (age = 70.98±7.90 years diagnosed with LBP. Anthropometric characteristics (BMI and functional performances (lower limb function, balance and mobility, and hand grip strength were measured. Muscle strength (abdominal and back muscle strength was assessed using the Baseline® Mechanical Push/Pull Dynamometer, while muscle control (transverse abdominus and multifidus was measured by using the Pressure Biofeedback Unit. The pain intensity and the level of kinesiophobia were measured using Numerical Rating Scale and Tampa Scale of Kinesiophobia, respectively. Data were analyzed using Pearson’s correlation coefficients and multivariate linear regressions. Results. No significant correlations were found between kinesiophobia and pain and muscle functions (all p>0.05. Kinesiophobia was significantly correlated with mobility and balance (p=0.038, r=0.263. Regressions analysis showed that kinesiophobia was a significant predictor of mobility and balance (p=0.038. Conclusion. We can conclude that kinesiophobia predicted mobility and balance in older persons with LBP. Kinesiophobia should be continuously assessed in clinical settings to recognize the obstacles that may affect patient’s compliance towards a rehabilitation program in older persons with LBP.

  7. Tracheal palpation to assess endotracheal tube depth: an exploratory study.

    Science.gov (United States)

    McKay, William P; Klonarakis, Jim; Pelivanov, Vladko; O'Brien, Jennifer M; Plewes, Chris

    2014-03-01

    Correct placement of the endotracheal tube (ETT) occurs when the distal tip is in mid-trachea. This study compares two techniques used to place the ETT at the correct depth during intubation: tracheal palpation vs placement at a fixed depth at the patient's teeth. With approval of the Research Ethics Board, we recruited American Society of Anesthesiologists physical status I-II patients scheduled for elective surgery with tracheal intubation. Clinicians performing the tracheal intubations were asked to "advance the tube slowly once the tip is through the cords". An investigator palpated the patient's trachea with three fingers spread over the trachea from the larynx to the sternal notch. When the ETT tip was felt in the sternal notch, the ETT was immobilized and its position was determined by fibreoptic bronchoscopy. The position of the ETT tip was compared with our hospital standard, which is a depth at the incisors or gums of 23 cm for men and 21 cm for women. The primary outcome was the incidence of correct placement. Correct placement of the ETT was defined as a tip > 2.5 cm from the carina and > 3.5 cm below the vocal cords. Movement of the ETT tip was readily palpable in 77 of 92 patients studied, and bronchoscopy was performed in 85 patients. Placement by tracheal palpation resulted in more correct placements (71 [77%]; 95% confidence interval [CI] 74 to 81) than hospital standard depth at the incisors or gums (57 [61%]; 95% CI 58 to 66) (P = 0.037). The mean (SD) placement of the ETT tip in palpable subjects was 4.1 (1.7) cm above the carina, 1.9 cm (1.5-2.3 cm) below the ideal mid-tracheal position. Tracheal palpation requires no special equipment, takes only a few seconds to perform, and may improve ETT placement at the correct depth. Further studies are warranted.

  8. Peripheral Nerve Function and Lower Extremity Muscle Power in Older Men

    DEFF Research Database (Denmark)

    Ward, Rachel E; Caserotti, Paolo; Faulkner, Kimberly

    2014-01-01

    To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men.......To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men....

  9. Skeletal Muscle Mitochondrial Function in Polycystic Ovarian Syndrome

    DEFF Research Database (Denmark)

    Rabøl, Rasmus; Svendsen, Pernille Maj; Skovbro, Mette

    2011-01-01

    Hyperinsulinemic euglycemic clamps (40 mU/min/m2) and muscle biopsies were performed on 23 women with PCOS (9 lean (body mass index (BMI) 25 kg/m2)) and 17 age- and weight-matched controls (6 lean and 11 obese). Western blotting and high-resolution respirometry was used to determine mitochondrial function. Results......Objective Polycystic ovarian syndrome (PCOS) is associated with skeletal muscle insulin resistance, which has been linked to decreased mitochondrial function. We measured mitochondrial respiration in lean and obese women with and without PCOS using high-resolution respirometry. Methods...... Insulin sensitivity decreased with PCOS and increasing body weight. Mitochondrial respiration with substrates for complex I and complex I+II were similar in all groups, and PCOS was not associated with a decrease in mitochondrial content as measured by mtDNA/genomicDNA. We found no correlation between...

  10. Optical-Based Artificial Palpation Sensors for Lesion Characterization

    Directory of Open Access Journals (Sweden)

    Hee-Jun Park

    2013-08-01

    Full Text Available Palpation techniques are widely used in medical procedures to detect the presence of lumps or tumors in the soft breast tissues. Since these procedures are very subjective and depend on the skills of the physician, it is imperative to perform detailed a scientific study in order to develop more efficient medical sensors to measure and generate palpation parameters. In this research, we propose an optical-based, artificial palpation sensor for lesion characterization. This has been developed using a multilayer polydimethylsiloxane optical waveguide. Light was generated at the critical angle to reflect totally within the flexible and transparent waveguide. When a waveguide was compressed by an external force, its contact area would deform and cause the light to scatter. The scattered light was captured by a high-resolution camera and saved as an image format. To test the performance of the proposed system, we used a realistic tissue phantom with embedded hard inclusions. The experimental results show that the proposed sensor can detect inclusions and provide the relative value of size, depth, and Young’s modulus of an inclusion.

  11. Functional Effects of Hyperthyroidism on Cardiac Papillary Muscle in Rats

    Directory of Open Access Journals (Sweden)

    Fabricio Furtado Vieira

    Full Text Available Abstract Background: Hyperthyroidism is currently recognized to affect the cardiovascular system, leading to a series of molecular and functional changes. However, little is known about the functional influence of hyperthyroidism in the regulation of cytoplasmic calcium and on the sodium/calcium exchanger (NCX in the cardiac muscle. Objectives: To evaluate the functional changes in papillary muscles isolated from animals with induced hyperthyroidism. Methods: We divided 36 Wistar rats into a group of controls and another of animals with hyperthyroidism induced by intraperitoneal T3 injection. We measured in the animals' papillary muscles the maximum contraction force, speed of contraction (+df/dt and relaxation (-df/dt, contraction and relaxation time, contraction force at different concentrations of extracellular sodium, post-rest potentiation (PRP, and contraction force induced by caffeine. Results: In hyperthyroid animals, we observed decreased PRP at all rest times (p < 0.05, increased +df/dt and -df/dt (p < 0.001, low positive inotropic response to decreased concentration of extracellular sodium (p < 0.001, reduction of the maximum force in caffeine-induced contraction (p < 0.003, and decreased total contraction time (p < 0.001. The maximal contraction force did not differ significantly between groups (p = 0.973. Conclusion: We hypothesize that the changes observed are likely due to a decrease in calcium content in the sarcoplasmic reticulum, caused by calcium leakage, decreased expression of NCX, and increased expression of a-MHC and SERCA2.

  12. Functional Effects of Hyperthyroidism on Cardiac Papillary Muscle in Rats.

    Science.gov (United States)

    Vieira, Fabricio Furtado; Olivoto, Robson Ruiz; Silva, Priscyla Oliveira da; Francisco, Julio Cesar; Fogaça, Rosalvo Tadeu Hochmuller

    2016-12-01

    Hyperthyroidism is currently recognized to affect the cardiovascular system, leading to a series of molecular and functional changes. However, little is known about the functional influence of hyperthyroidism in the regulation of cytoplasmic calcium and on the sodium/calcium exchanger (NCX) in the cardiac muscle. To evaluate the functional changes in papillary muscles isolated from animals with induced hyperthyroidism. We divided 36 Wistar rats into a group of controls and another of animals with hyperthyroidism induced by intraperitoneal T3 injection. We measured in the animals' papillary muscles the maximum contraction force, speed of contraction (+df/dt) and relaxation (-df/dt), contraction and relaxation time, contraction force at different concentrations of extracellular sodium, post-rest potentiation (PRP), and contraction force induced by caffeine. In hyperthyroid animals, we observed decreased PRP at all rest times (p < 0.05), increased +df/dt and -df/dt (p < 0.001), low positive inotropic response to decreased concentration of extracellular sodium (p < 0.001), reduction of the maximum force in caffeine-induced contraction (p < 0.003), and decreased total contraction time (p < 0.001). The maximal contraction force did not differ significantly between groups (p = 0.973). We hypothesize that the changes observed are likely due to a decrease in calcium content in the sarcoplasmic reticulum, caused by calcium leakage, decreased expression of NCX, and increased expression of a-MHC and SERCA2.

  13. Alfacalcidol improves muscle power, muscle function and balance in elderly patients with reduced bone mass.

    Science.gov (United States)

    Schacht, E; Ringe, Johann D

    2012-01-01

    We investigated the effect of daily therapy with 1 mcg alfacalcidol (Doss(®)-TEVA/AWD-pharma) on muscle power, muscle function, balance performance and fear of falls in an open, multi-centered, uncontrolled, prospective study on a cohort of patients with reduced bone mass. Among the 2,097 participants, 87.1% were post-menopausal women and 12.9% were men. Mean age was 74.8 years and mean body mass index (BMI) 26.3 kg/m². A total of 75.3% of the study population had osteoporosis, 81% a diagnosis of "increased risk of falls" and 70.1% had a creatinine clearance (CrCl) of power tests at onset and after 3 and 6 months: the timed up and go test (TUG) and the chair rising test (CRT). At baseline and after 6 months, participants performed the tandem gait test (TGT) and filled out a questionnaire evaluating fear of falling. Successful performance in the muscle tests is associated with a significantly lower risk of falls and non-vertebral fractures in elderly patients (successful test performance: TUG ≤ 10 s (sec), CRT ≤ 10 s, TGT ≥ 8 steps). A significant improvement in the performance of the two muscle tests was proved already after 3 months of treatment with alfacalcidol and further increased by the end of the therapeutic intervention. There were significant increases in the number of participants able to successfully perform the tests: 24.6% at baseline and 46.3% at the end of trial for the TUG (P balance test (TGT) increased from 36.0% at onset to 58.6% at the end of the trial (P power, muscle function and balance and reduces fear of falls. The significant improvement in the three muscle and balance tests and fear of falls may have a preventative effect on falls and fractures. We suggest that the quantitative risk tests used in this study could be reliable surrogate parameters for the risk of falls and fractures in elderly patients.

  14. Effects of acupuncture on symptoms and muscle function in delayed-onset muscle soreness.

    Science.gov (United States)

    Hübscher, Markus; Vogt, Lutz; Bernhörster, Marcus; Rosenhagen, Andreas; Banzer, Winfried

    2008-10-01

    This study was done to investigate the effects of a standardized acupuncture treatment on symptoms and muscle function in exercise-induced delayed-onset muscle soreness (DOMS). A prospective, randomized, controlled, observer and subject-blinded trial was undertaken. Twenty-two (22) healthy subjects (22-30 years; 10 males and 12 females) were randomly assigned to three treatment groups: real acupuncture (deep needling at classic acupuncture points and tender points; n = 7), sham-acupuncture (superficial needling at nonacupuncture points; n = 8), and control (no needling; n = 7). DOMS of the nondominant elbow-flexors was experimentally induced through eccentric contractions until exhaustion. The outcome measures were pain perception (visual analogue scale; VAS; range: 0-10 cm), mechanical pain threshold (MPT; pressure algometer), and maximum isometric voluntary force (MIVF; force transducer). Treatment was applied immediately, 24 and 48 hours after DOMS induction. Measurements of MPT and MIVF were made prior to DOMS induction as well as before and after every treatment session. VAS data were acquired after DOMS induction as well as pre- and post-treatment. Final pain, MPT, and MIVF measurements were performed 72 hours after DOMS induction. Following nonparametric testing, there were no significant differences between groups in outcome measures at baseline. After 72 hours, pain perception (VAS) was significantly lower in the acupuncture group compared to the sham acupuncture and control subjects. However, the mean MPT and MIVF scores were not significantly different between groups. Although acupuncture seemed to have no effects on mechanical pain threshold and muscle function, it proved to reduce perceived pain arising from exercise-induced muscle soreness.

  15. Effects of aging on muscle mechanical function and muscle fiber morphology during short-term immobilization and subsequent retraining

    DEFF Research Database (Denmark)

    Hvid, Lars; Aagaard, Per; Justesen, Lene

    2010-01-01

    to the deleterious effects of short-term muscle disuse on muscle fiber size and rapid force capacity than YM. Furthermore, OM seems to require longer time to recover and regain rapid muscle force capacity, which may lead to a larger risk of falling in aged individuals after periods of short-term disuse.......Very little attention has been given to the combined effects of aging and disuse as separate factors causing deterioration in muscle mechanical function. Thus the purpose of this study was to investigate the effects of 2 wk of immobilization followed by 4 wk of retraining on knee extensor muscle...... mechanical function (e.g., maximal strength and rapid force capacity) and muscle fiber morphology in 9 old (OM: 67.3 ± 1.3 yr) and 11 young healthy men (YM: 24.4 ± 0.5 yr) with comparable levels of physical activity. Following immobilization, OM demonstrated markedly larger decreases in rapid force capacity...

  16. New function of the myostatin/activin type I receptor (ALK4) as a mediator of muscle atrophy and muscle regeneration.

    NARCIS (Netherlands)

    Pasteuning-Vuhman, S.; Boertje-van der Meulen, J.; van Putten, M.; Overzier, M.; ten Dijke, P; Kiełbasa, S.M.; Arindrarto, W.; Wolterbeek, R.; Lezhnina, K.V.; Ozerov, I.V.; Aliper, A.M.; Hoogaars, W.; Aartsma-Rus, A; Loomans, C.J.

    Skeletal muscle fibrosis and impaired muscle regeneration are major contributors to muscle wasting in Duchenne muscular dystrophy (DMD). Muscle growth is negatively regulated by myostatin (MSTN) and activins. Blockage of these pathways may improve muscle quality and function in DMD. Antisense

  17. Assessment of the Short-Term Effectiveness of Kinesiotaping and Trigger Points Release Used in Functional Disorders of the Masticatory Muscles

    Directory of Open Access Journals (Sweden)

    Danuta Lietz-Kijak

    2018-01-01

    Full Text Available Chronic face pain syndrome is a diagnostic and therapeutic problem for many specialists, and this proves the interdisciplinary and complex nature of this ailment. Physiotherapy is of particular importance in the treatment of pain syndrome in the course of temporomandibular joint functional disorders. In patients with long-term dysfunction of masticatory muscles, the palpation examination can localize trigger points, that is, thickening in the form of nodules in the size of rice grains or peas. Latent trigger points located in the muscles can interfere with muscular movement patterns, cause cramps, and reduce muscle strength. Because hidden trigger points can spontaneously activate, they should be found and released to prevent further escalation of the discomfort. Kinesiotaping (KT is considered as an intervention that can be used to release latent myofascial trigger points. It is a method that involves applying specific tapes to the patient’s skin in order to take advantage of the natural self-healing processes of the body. The aim of the study was to evaluate the effect of the kinesiotaping method and trigger points inactivation on the nonpharmacological elimination of pain in patients with temporomandibular disorders. The study was conducted in 60 patients (18 to 35 years old. The subjects were randomly divided into two subgroups of 30 people each. Group KT (15 women and 15 men were subjected to active kinesiotaping application. Group TrP, composed of 16 women and 14 men, was subjected to physiotherapy with the release of trigger points by the ischemic compression method. The results show that the KT method and TrP inactivation brought significant therapeutic analgesic effects in the course of pain-related functional disorders of the muscles of mastication. The more beneficial outcomes of the therapy were observed after using the KT method, which increased the analgesic effect in dysfunctional patients.

  18. Structural, biochemical, cellular, and functional changes in skeletal muscle extracellular matrix with aging

    DEFF Research Database (Denmark)

    Kragstrup, T W; Kjaer, M; Mackey, A L

    2011-01-01

    The extracellular matrix (ECM) of skeletal muscle is critical for force transmission and for the passive elastic response of skeletal muscle. Structural, biochemical, cellular, and functional changes in skeletal muscle ECM contribute to the deterioration in muscle mechanical properties with aging....... Structural changes include an increase in the collagen concentration, a change in the elastic fiber system, and an increase in fat infiltration of skeletal muscle. Biochemical changes include a decreased turnover of collagen with potential accumulation of enzymatically mediated collagen cross...

  19. Relationship between Muscle Function, Muscle Typology and Postural Performance According to Different Postural Conditions in Young and Older Adults.

    Science.gov (United States)

    Paillard, Thierry

    2017-01-01

    Although motor output of the postural function clearly influences postural performance in young and older subjects, no relationship has been formally established between them. However, the relationship between lower-extremity muscle strength/power and postural performance is often pointed out, especially in older subjects. In fact, the influence of motor output may vary according to the postural condition considered (e.g., static, dynamic, challenging, disturbing). In static postural condition, there may be a relationship between lower-extremity muscle strength and postural performance when the value of muscle strength is below a certain threshold in older subjects. Above this threshold of muscle strength, this relationship may disappear. In dynamic postural condition, lower-extremity muscle power could facilitate compensatory postural actions, limiting induced body imbalance likely to generate falls in older subjects. In young subjects, there could be a relationship between very early rapid torque of the leg extensor muscles and postural performance. In the case of postural reaction to (external) perturbations, a high percentage of type II muscle fibers could be associated with the ability to react quickly to postural perturbations in young subjects, while it may enable a reduction in the risk of falls in older subjects. In practice, in older subjects, muscle strength and/or power training contributes to reducing the risk of falls, as well as slowing down the involution of muscle typology regarding type II muscle fibers.

  20. [Analysis of images in Japanese book Fukusho-Kiran (Medical Book Focusing on Abdominal Palpation) and Fukusho-Kiran yoku (Supplement to Medical Book Focusing on Abdominal Palpation)].

    Science.gov (United States)

    Zhang, Lijun; DI, Kan; Song, Yuanliang

    2014-09-01

    Hukusyo-kiran (Medical Book Focusing on Abdominal Palpation) and Hukusyo-kiran yoku (Supplement to Medical Book Focusing on Abdominal Palpation) are two typical monographs of Fukushin (abdominal palpation), with a total of 148 images about abdominal palpation. These images can be divided into 5 kinds: locations, theories, techniques, diseases and medicines, with its own system covering the theories, principles, prescriptions and medicines of abdominal palpation. It can be used as a guide for clinicians to differentiate the locations and qualities of diseases, confirm the principles of treatment, guide the usage of medicines, and predict the prognosis, with the rather high theoretic and academic value, deserving further research and analysis for the modern scholars.

  1. Self-organization of muscle cell structure and function.

    Directory of Open Access Journals (Sweden)

    Anna Grosberg

    2011-02-01

    Full Text Available The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton.

  2. Self-organization of muscle cell structure and function.

    Science.gov (United States)

    Grosberg, Anna; Kuo, Po-Ling; Guo, Chin-Lin; Geisse, Nicholas A; Bray, Mark-Anthony; Adams, William J; Sheehy, Sean P; Parker, Kevin Kit

    2011-02-01

    The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton.

  3. Fish axial muscle : structure-function relationships on a micro-level

    NARCIS (Netherlands)

    Spierts, I.L.Y.

    2000-01-01

    This paper discusses some examples of strong correlations between functions and structures in axial fish muscle on a micro-level. Muscle tissue needs a certain elasticity to cope with the diverse functional requirements necessary for swimming. During fast-starts of carp, muscles can be stretched up

  4. A three-dimensional study of the musculotendinous and neurovascular architecture of the gracilis muscle: application to functional muscle transfer.

    Science.gov (United States)

    Fattah, A Y; Ravichandiran, K; Zuker, R M; Agur, A M R

    2013-09-01

    Muscle transfer is used to restore function typically using a single vector of contraction. Although its use with two independently functional muscular units has been employed, in order to refine this concept we endeavoured to detail the intramuscular anatomy of gracilis, a muscle commonly used for transfer. A novel method to capture intramuscular fibre bundle and neurovascular arrangement was used to create a three-dimensional (3D) digital model that allowed for accurate representation of the relationships between all the intramuscular structures to facilitate flap planning. Twenty gracilis muscles were harvested from 15 cadavers. All components of the muscle were digitised using a Microscribe G2 Digitiser. The data were exported to the 3D animation software Autodesk(®) Maya(®) 2012 whereupon it was rendered into a 3D model that can be exported as static images or videos. Neurovascular anatomy and muscle architecture were analysed from these models, and fibre bundle length, pennation angle and physiological cross-sectional area were calculated from digitised data. The muscle is composed of a variable number of distinct longitudinal segments with muscle fibres spiralling onto the tendon. The main artery to the muscle has three main intramuscular patterns of distribution. The venae comitantes drain discrete zones without intramuscular macroscopic anastomoses. The minor pedicles form an anastomotic chain along the anterior border of the muscle and all vessels were biased to the deep surface. The nerve is related to the vessels in a variable manner and both run between longitudinal muscular compartments. The digitisation technique may be used to advance knowledge of intramuscular architecture and it demonstrated that the gracilis muscle is comprised of four to seven muscular compartments, each representing a functional unit that may theoretically be differentially activated and could be harnessed for more sophisticated muscle transfers. Copyright © 2013 British

  5. Effects of protein supplements on muscle damage, soreness and recovery of muscle function and physical performance: a systematic review.

    Science.gov (United States)

    Pasiakos, Stefan M; Lieberman, Harris R; McLellan, Tom M

    2014-05-01

    Protein supplements are frequently consumed by athletes and recreationally-active individuals, although the decision to purchase and consume protein supplements is often based on marketing claims rather than evidence-based research. To provide a systematic and comprehensive analysis of literature examining the hypothesis that protein supplements enhance recovery of muscle function and physical performance by attenuating muscle damage and soreness following a previous bout of exercise. English language articles were searched with PubMed and Google Scholar using protein and supplements together with performance, exercise, competition and muscle, alone or in combination as keywords. Inclusion criteria required studies to recruit healthy adults less than 50 years of age and to evaluate the effects of protein supplements alone or in combination with carbohydrate on performance metrics including time-to-exhaustion, time-trial or isometric or isokinetic muscle strength and markers of muscle damage and soreness. Twenty-seven articles were identified of which 18 dealt exclusively with ingestion of protein supplements to reduce muscle damage and soreness and improve recovery of muscle function following exercise, whereas the remaining 9 articles assessed muscle damage as well as performance metrics during single or repeat bouts of exercise. Papers were evaluated based on experimental design and examined for confounders that explain discrepancies between studies such as dietary control, training state of participants, sample size, direct or surrogate measures of muscle damage, and sensitivity of the performance metric. High quality and consistent data demonstrated there is no apparent relationship between recovery of muscle function and ratings of muscle soreness and surrogate markers of muscle damage when protein supplements are consumed prior to, during or after a bout of endurance or resistance exercise. There also appears to be insufficient experimental data

  6. Muscle Functional Morphology in Paleobiology: The Past, Present, and Future of "Paleomyology".

    Science.gov (United States)

    Perry, Jonathan M G; Prufrock, Kristen A

    2018-03-01

    Our knowledge of muscle anatomy and physiology in vertebrates has increased dramatically over the last two-hundred years. Today, much is understood about how muscles contract and about the functional meaning of muscular variation at multiple scales. Progress in muscle anatomy has profited from the availability of broad comparative samples, advances in microscopy have permitted comparisons at increasingly finer scales, and progress in muscle physiology has profited from many carefully designed and executed experiments. Several avenues of future work are promising. In particular, muscle ontogeny (growth and development) is poorly understood for many vertebrate groups. We consider which types of advances in muscle functional morphology are of use to paleobiologists. These are only a modest subset for muscle anatomy and a very small subset for muscle physiology. The relationship between muscle and bone - spatially and mechanically-is critical to any future advances in "paleomyology". Anat Rec, 301:538-555, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  7. Functional compartmentalization of the human superficial masseter muscle.

    Directory of Open Access Journals (Sweden)

    Rodrigo A Guzmán-Venegas

    Full Text Available Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM muscle's motor units using high-density surface electromyography (EMGs at different bite force levels. Twenty healthy natural dentate participants (men: 4; women: 16; age 20±2 years; mass: 60±12 kg, height: 163±7 cm were selected from 316 volunteers and included in this study. Using a gnathodynamometer, bites from 20 to 100% maximum voluntary bite force (MVBF were randomly requested. Using a two-dimensional grid (four columns, six electrodes located on the dominant SM, EMGs in the anterior, middle-anterior, middle-posterior and posterior portions were simultaneously recorded. In bite ranges from 20 to 60% MVBF, the EMG activity was higher in the anterior than in the posterior portion (p-value = 0.001.The center of mass of the EMG activity was displaced towards the posterior part when bite force increased (p-value = 0.001. The topographic distribution of EMGs was more homogeneous at high levels of MVBF (p-value = 0.001. The results of this study show that the superficial masseter is organized into three functional compartments: an anterior, a middle and a posterior compartment. However, this compartmentalization is only seen at low levels of bite force (20-60% MVBF.

  8. Intraexaminer and interexaminer reliability of manual palpation and pressure algometry of the lower limb nerves in asymptomatic subjects.

    LENUS (Irish Health Repository)

    Fingleton, Caitriona P

    2014-02-01

    Nerve palpation is a method of clinically identifying mechanosensitivity of neural tissue by means of pressure algometry and manual palpation. There are few investigations of the reliability of lower limb nerve palpation, and femoral nerve palpation has never been previously reported. The aim of this study was to investigate the reliability of nerve palpation of the femoral, sciatic, tibial, and common peroneal nerves and to report normative values for the femoral nerve.

  9. Functional coordination of muscles underlying changes in behavioural dynamics.

    Science.gov (United States)

    Vernooij, Carlijn A; Rao, Guillaume; Perdikis, Dionysios; Huys, Raoul; Jirsa, Viktor K; Temprado, Jean-Jacques

    2016-06-10

    The dynamical systems approach addresses Bernstein's degrees of freedom problem by assuming that the neuro-musculo-skeletal system transiently assembles and dismantles its components into functional units (or synergies) to meet task demands. Strikingly, little is known from a dynamical point of view about the functioning of the muscular sub-system in this process. To investigate the interaction between the dynamical organisation at muscular and behavioural levels, we searched for specific signatures of a phase transition in muscular coordination when a transition is displayed at the behavioural level. Our results provide evidence that, during Fitts' task when behaviour switches to a different dynamical regime, muscular activation displays typical signatures of a phase transition; a reorganisation in muscular coordination patterns accompanied by a peak in the variability of muscle activation. This suggests that consistent changes occur in coordination processes across the different levels of description (i.e., behaviour and muscles). Specifically, in Fitts' task, target size acts as a control parameter that induces a destabilisation and a reorganisation of coordination patterns at different levels of the neuro-musculo-skeletal system.

  10. Evaluation of abdominal palpation, radiography and ultrasonography for pregenancy diagnosis in bitches

    International Nuclear Information System (INIS)

    Arunmozhi, N.; Naidu, K.V.; Sreenu, M.; Rao, A.S.

    2005-01-01

    Abdominal palpation, radiography and ultrasonography were compared for pregnancy diagnosis in bitches. The earliest correct diagnosis of pregnancy was made by 22 and 21 days with abdominal palpation and ultrasonography respectively, while radiography led to more accurate diagnosis in last trimester of pregnancy. All the methods revealed 100 per cent accuracy in last trimester where as ultrasonography gave constant results from day 21 up to termination of pregnancy followed by abdominal palpation

  11. The Changes of Muscle Strength and Functional Activities During Aging in Male and Female Populations

    Directory of Open Access Journals (Sweden)

    Shih-Jung Cheng

    2014-12-01

    Conclusion: We noted that the muscle strength and functional activities were decreased earlier in female than male individuals. The decrease of functional activities during the aging process seems to be earlier than the decrease of muscle strength. It is important to implement functional activities training in addition to strengthening exercise to maintain functional levels of the geriatric population.

  12. Relationship between muscle strength and motor function in Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Milene F. Nunes

    2016-07-01

    Full Text Available ABSTRACT Measuring muscle strength and motor function is part of Duchenne muscular dystrophy (DMD assessment. However, the relationship between these variables is controversial. Objective To investigate the relationship between muscle strength and motor function and between these variables and age. Method Muscle strength was measured by Medical Research Council (MRC scale and motor function, by Motor Function Measure (MFM, in 40 non-ambulatory patients. Spearman tests investigated the relationships between muscle strength, motor function and age. Results Total MRC and MFM scores were strongly related to each other (r = 0.94; p 0.05. Strong and moderate relationships between partial muscle strength and motor function scores were found. Higher correlation coefficients were found between total scores and Dimensions 2 (axial/ proximal control and 3 (distal control of MFM. Conclusion Muscle strength and motor function are strongly correlated and seem to decrease proportionally in DMD.

  13. Preprocedural ultrasound examination versus manual palpation for thoracic epidural catheter insertion

    Directory of Open Access Journals (Sweden)

    Ahmed M Hasanin

    2017-01-01

    Conclusion: Preprocedural ultrasound imaging increased the incidence of first pass success in thoracic epidural catheter insertion and reduced the catheter insertion time compared to manual palpation method.

  14. The Assessment Methods of Laryngeal Muscle Activity in Muscle Tension Dysphonia: A Review

    Science.gov (United States)

    Khoddami, Seyyedeh Maryam; Nakhostin Ansari, Noureddin; Izadi, Farzad; Talebian Moghadam, Saeed

    2013-01-01

    The purpose of this paper is to review the methods used for the assessment of muscular tension dysphonia (MTD). The MTD is a functional voice disorder associated with abnormal laryngeal muscle activity. Various assessment methods are available in the literature to evaluate the laryngeal hyperfunction. The case history, laryngoscopy, and palpation are clinical methods for the assessment of patients with MTD. Radiography and surface electromyography (EMG) are objective methods to provide physiological information about MTD. Recent studies show that surface EMG can be an effective tool for assessing muscular tension in MTD. PMID:24319372

  15. Sensory nerve cross-anastomosis and electrical muscle stimulation synergistically enhance functional recovery of chronically denervated muscle.

    Science.gov (United States)

    Willand, Michael P; Holmes, Michael; Bain, James R; de Bruin, Hubert; Fahnestock, Margaret

    2014-11-01

    Long-term muscle denervation leads to severe and irreversible atrophy coupled with loss of force and motor function. These factors contribute to poor functional recovery following delayed reinnervation. The authors' previous work demonstrated that temporarily suturing a sensory nerve to the distal motor stump (called sensory protection) significantly reduces muscle atrophy and improves function following reinnervation. The authors have also shown that 1 month of electrical stimulation of denervated muscle significantly improves function and reduces atrophy. In this study, the authors tested whether a combination of sensory protection and electrical stimulation would enhance functional recovery more than either treatment alone. Rat gastrocnemius muscles were denervated by cutting the tibial nerve. The peroneal nerve was then sutured to the distal tibial stump following 3 months of treatment (i.e., electrical stimulation, sensory protection, or both). Three months after peroneal repair, functional and histologic measurements were taken. All treatment groups had significantly higher muscle weight (pstimulation or sensory protection alone. The combined treatment also produced motor unit counts significantly greater than sensory protection alone (p<0.05). The combination treatment synergistically reduces atrophy and improves reinnervation and functional measures following delayed nerve repair, suggesting that these approaches work through different mechanisms. The authors' research supports the clinical use of both modalities together following peripheral nerve injury.

  16. Could a functional artificial skeletal muscle be useful in muscle wasting?

    Science.gov (United States)

    Fuoco, Claudia; Cannata, Stefano; Gargioli, Cesare

    2016-05-01

    Regardless of the underlying cause, skeletal muscle wasting is detrimental for a person's life quality, leading to impaired strength, locomotion, and physiological activity. Here, we propose a series of studies presenting tissue engineering-based approaches to reconstruct artificial muscle in vitro and in vivo. Skeletal muscle tissue engineering is attracting more and more attention from scientists, clinicians, patients, and media, thanks to the promising results obtained in the last decade with animal models of muscle wasting. The use of novel and refined biomimetic scaffolds mimicking three-dimensional muscle environment, thus supporting cell survival and differentiation, in combination with well characterized myogenic stem/progenitor cells, revealed the noteworthy potential of these technologies for creating artificial skeletal muscle tissue. In vitro, the production of three-dimensional muscle structures offer the possibility to generate a drug-screening platform for patient-specific pharmacological treatment, opening new frontiers in the development of new compounds with specific therapeutic actions. In vivo, three-dimensional artificial muscle biomimetic constructs offer the possibility to replace, in part or entirely, wasted muscle by means of straight reconstruction and/or by enhancing endogenous regeneration. Reports of tissue engineering approaches for artificial muscle building appeared in large numbers in the specialized press lately, advocating the suitability of this technology for human application upon scaling up and a near future applicability for medical care of muscle wasting. http://links.lww.com/COCN/A9

  17. Muscle fibre types of fishes : structural and functional specialization

    NARCIS (Netherlands)

    Akster, H.A.

    1984-01-01

    Muscles of fishes are active in a variety of movements that differ in velocity, duration and excursion length. To investigate how muscles meet the, often conflicting, demands imposed upon them by these movements, the fibre type composition of several muscles was determined. The ultrastructural and

  18. IL-6 signaling blockade increases inflammation but does not affect muscle function in the mdx mouse

    Directory of Open Access Journals (Sweden)

    Kostek Matthew C

    2012-06-01

    Full Text Available Abstract Background IL-6 is a pleiotropic cytokine that modulates inflammatory responses and plays critical roles in muscle maintenance and remodeling. In the mouse model (mdx of Duchenne Muscular Dystrophy, IL-6 and muscle inflammation are elevated, which is believed to contribute to the chronic inflammation and failure of muscle regeneration in DMD. The purpose of the current study was to examine the effect of blocking IL-6 signaling on the muscle phenotype including muscle weakness and pathology in the mdx mouse. Methods A monoclonal antibody against the IL-6 receptor (IL-6r mAb that blocks local and systemic IL-6 signaling was administered to mdx and BL-10 mice for 5 weeks and muscle function, histology, and inflammation were examined. Results IL-6r mAb treatment increased mdx muscle inflammation including total inflammation score and ICAM-1 positive lumens in muscles. There was no significant improvement in muscle strength nor muscle pathology due to IL-6r mAb treatment in mdx mice. Conclusions These results showed that instead of reducing inflammation, IL-6 signaling blockade for 5 weeks caused an increase in muscle inflammation, with no significant change in indices related to muscle regeneration and muscle function. The results suggest a potential anti-inflammatory instead of the original hypothesized pro-inflammatory role of IL-6 signaling in the mdx mice.

  19. Systemic Inflammation in Duchenne Muscular Dystrophy: Association with Muscle Function and Nutritional Status

    OpenAIRE

    Oriana del Rocío Cruz-Guzmán; Maricela Rodríguez-Cruz; Rosa Elena Escobar Cedillo

    2015-01-01

    Inflammation described in patients with Duchenne muscular dystrophy (DMD) may be related to loss of muscle function or to obesity. It is unknown if circulating proinflammatory cytokines (IL-6, IL-1, and TNF-α) levels are associated with muscle function. The purpose was to evaluate whether an association exists between systemic inflammation with muscle function and nutritional status in DMD patients. In 66 DMD patients without corticosteroid treatment, the following were evaluated in serum: cy...

  20. Phosphodiesterases regulate airway smooth muscle function in health and disease.

    Science.gov (United States)

    Krymskaya, Vera P; Panettieri, Reynold A

    2007-01-01

    On the basis of structure, regulation, and kinetic properties, phosphodiesterases (PDEs) represent a superfamily of enzymes divided into 11 subfamilies that catalyze cytosolic levels of 3',5'-cyclic adenosine monophosphate (cAMP) or 3',5'-cyclic guanosine monophosphate (cGMP) to 5'-AMP or 5'-GMP, respectively. PDE4 represents the major PDE expressed in inflammatory cells as well as airway smooth muscle (ASM), and selective PDE4 inhibitors provide a broad spectrum of anti-inflammatory effects such as abrogating cytokine and chemokine release from inflammatory cells and inhibiting inflammatory cell trafficking. Due to cell- and tissue-specific gene expression and regulation, PDEs modulate unique organ-based functions. New tools or compounds that selectively inhibit PDE subfamilies and genetically engineered mice deficient in selective isoforms have greatly enhanced our understanding of PDE function in airway inflammation and resident cell function. This chapter will focus on recent advances in our understanding of the role of PDE in regulating ASM function.

  1. Bioactive peptides from meat muscle and by-products: generation, functionality and application as functional ingredients.

    Science.gov (United States)

    Lafarga, Tomas; Hayes, Maria

    2014-10-01

    Bioactive peptides are sequences of between 2-30 amino acids in length that impart a positive health effect to the consumer when ingested. They have been identified from a range of foods, including milk and muscle sources including beef, chicken, pork and marine muscles. The myriad of peptides identified from these sources have known antihypertensive, opioid, antioxidant, antithrombotic and other bioactivities. Indeed, bioactive peptides could play a role in the prevention of diseases associated with the development of metabolic syndrome and mental health diseases. The aim of this work is to present an overview of the bioactive peptides identified in muscle proteins and by-products generated during the processing of meat. The paper looks at the isolation, enrichment and characterisation strategies that have been employed to date to generate bioactive peptides and the potential future applications of these peptides in functional foods for the prevention of heart and mental health problems and obesity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Systemic down-regulation of delta-9 desaturase promotes muscle oxidative metabolism and accelerates muscle function recovery following nerve injury.

    Directory of Open Access Journals (Sweden)

    Ghulam Hussain

    Full Text Available The progressive deterioration of the neuromuscular axis is typically observed in degenerative conditions of the lower motor neurons, such as amyotrophic lateral sclerosis (ALS. Neurodegeneration in this disease is associated with systemic metabolic perturbations, including hypermetabolism and dyslipidemia. Our previous gene profiling studies on ALS muscle revealed down-regulation of delta-9 desaturase, or SCD1, which is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Interestingly, knocking out SCD1 gene is known to induce hypermetabolism and stimulate fatty acid beta-oxidation. Here we investigated whether SCD1 deficiency can affect muscle function and its restoration in response to injury. The genetic ablation of SCD1 was not detrimental per se to muscle function. On the contrary, muscles in SCD1 knockout mice shifted toward a more oxidative metabolism, and enhanced the expression of synaptic genes. Repressing SCD1 expression or reducing SCD-dependent enzymatic activity accelerated the recovery of muscle function after inducing sciatic nerve crush. Overall, these findings provide evidence for a new role of SCD1 in modulating the restorative potential of skeletal muscles.

  3. Effect of strength training on muscle function in elderly hospitalized patients

    DEFF Research Database (Denmark)

    Suetta, C; Magnusson, S P; Beyer, N

    2007-01-01

    Immobilization due to hospitalization and major surgery leads to an increased risk of morbidity, disability and a decline in muscle function especially in frail elderly individuals. In fact, many elderly patients fail to regain their level of function and self-care before admission to hospital....... Given that reduced lower limb muscle strength and loss of skeletal muscle mass (i.e. sarcopenia) have been associated with functional impairments and disability with aging, attempts to counteract this process seem highly relevant. In recent years, strength training has emerged as an effective method...... to induce muscle hypertrophy and increase muscle strength and functional performance in frail elderly individuals. Furthermore, there is increasing evidence that strength training is an effective method to restore muscle function in post-operative patients and in patients with chronic diseases. Despite this...

  4. Engineered matrices for skeletal muscle satellite cell engraftment and function.

    Science.gov (United States)

    Han, Woojin M; Jang, Young C; García, Andrés J

    2017-07-01

    Regeneration of traumatically injured skeletal muscles is severely limited. Moreover, the regenerative capacity of skeletal muscle declines with aging, further exacerbating the problem. Recent evidence supports that delivery of muscle satellite cells to the injured muscles enhances muscle regeneration and reverses features of aging, including reduction in muscle mass and regenerative capacity. However, direct delivery of satellite cells presents a challenge at a translational level due to inflammation and donor cell death, motivating the need to develop engineered matrices for muscle satellite cell delivery. This review will highlight important aspects of satellite cell and their niche biology in the context of muscle regeneration, and examine recent progresses in the development of engineered cell delivery matrices designed for skeletal muscle regeneration. Understanding the interactions of muscle satellite cells and their niche in both native and engineered systems is crucial to developing muscle pathology-specific cell- and biomaterial-based therapies. Copyright © 2016 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

  5. Respiratory Muscle Training and Cognitive Function Exercising at Altitude.

    Science.gov (United States)

    Quackenbush, Joseph; Duquin, Aubrey; Helfer, Samuel; Pendergast, David R

    2016-01-01

    Hiking and trekking often occur at altitudes up to 12,000 ft altitude. The hypoxia-induced hyperventilation at altitude paradoxically reduces arterial CO2 (Paco2). A reduction in Paco2 results in vasoconstriction of the blood vessels of the brain and thus in local hypoxia. The local hypoxia likely affects cognitive function, which may result in reduced performance and altitude accidents. Recent publications have demonstrated that voluntary isocapnic hyperventilatory training of the respiratory muscles (VIHT) can markedly enhance exercise endurance as it is associated with reduced ventilation and its energy cost. VIHT may be useful in blunting the altitude-induced hyperventilation leading to higher Paco2 and improved cognitive function. This study examined the effects of VIHT, compared to control (C) and placebo (PVIHT) groups, on selected measures of executive functioning, including working memory and processing speed (i.e., Stroop Test, Symbol Digit Modalities Test, and Digit Span Forward) at simulated altitude up to 12,000 ft. Associated physiological parameters were also measured. The Digit Span Forward Test did not show improvements after VIHT in any group. The VIHT group, but not C or PVIHT groups, improved significantly (17-30%) on the Stroop Test. Similarly the VIHT group, but not the C and PVIHT groups, improved correct responses (26%) and number of attempts (24%) on the Symbol Digit Modalities Test. In addition, reaction time was also improved (16%). VIHT improved processing speed and working memory during exercise at altitude.

  6. Functional heterogeneity of side population cells in skeletal muscle

    International Nuclear Information System (INIS)

    Uezumi, Akiyoshi; Ojima, Koichi; Fukada, So-ichiro; Ikemoto, Madoka; Masuda, Satoru; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi

    2006-01-01

    Skeletal muscle regeneration has been exclusively attributed to myogenic precursors, satellite cells. A stem cell-rich fraction referred to as side population (SP) cells also resides in skeletal muscle, but its roles in muscle regeneration remain unclear. We found that muscle SP cells could be subdivided into three sub-fractions using CD31 and CD45 markers. The majority of SP cells in normal non-regenerating muscle expressed CD31 and had endothelial characteristics. However, CD31 - CD45 - SP cells, which are a minor subpopulation in normal muscle, actively proliferated upon muscle injury and expressed not only several regulatory genes for muscle regeneration but also some mesenchymal lineage markers. CD31 - CD45 - SP cells showed the greatest myogenic potential among three SP sub-fractions, but indeed revealed mesenchymal potentials in vitro. These SP cells preferentially differentiated into myofibers after intramuscular transplantation in vivo. Our results revealed the heterogeneity of muscle SP cells and suggest that CD31 - CD45 - SP cells participate in muscle regeneration

  7. Normal values for inspiratory muscle function in children

    International Nuclear Information System (INIS)

    Mellies, Uwe; Stehling, Florian; Dohna-Schwake, Christian

    2014-01-01

    Assessment of inspiratory muscle function (IMF) is limited in children with neuromuscular disorders, because respiratory muscle tests are poorly standardized and valid normative data are unavailable. We investigated maximum inspiratory pressure after exhalation to residual volume (MIP), mouth occlusion pressure (P0.1) and time of inspiration during quiet breathing and derived inspiratory muscle load (P0.1/MIP), and tension time index (TTI) in 301 healthy schoolchildren 6–16 years old. Gender-specific and age-dependent percentile curves for MIP were drawn with the median, 5%, 10%, 25%, 75% and 95% percentile. P0.1 was equal in boys and girls (0.23  ±  0.11 kPa), while MIP was significantly higher in boys (6.8  ±  2.2 versus 5.8  ±  2.4 kPa). Consequently, P0.1/MIP (4.8% ± 3.2% versus 4.0% ± 3.1%) and TTI (0.2  ±  0.14 versus 0.16  ±  0.14) were significantly higher in girls. MIP was 2.90 + 0.36 × age (kPa) and 3.19 + 0.24 × age (kPa) in boys and girls, respectively. The 95% confidence intervals for boys and girls, respectively, were MIP, 6.3–7.3 kPA and 5.4–6.2 kPa; P0.1/MIP, 3.5%–4.5% and 4.3%–5.3%; TTI, 0.14–0.18 and 0.18–0.22; and P0.1, 0.20–0.24 kPa for both. IMF in children has a wide interindividual variability; however percentile curves facilitate a longitudinal assessment of individual patients. Furthermore, narrow confidence intervals allow for comparisons of study populations, making IMF an appropriate endpoint for clinical trials. (paper)

  8. Suboptimal Muscle Synergy Activation Patterns Generalize their Motor Function across Postures.

    Science.gov (United States)

    Sohn, M Hongchul; Ting, Lena H

    2016-01-01

    We used a musculoskeletal model to investigate the possible biomechanical and neural bases of using consistent muscle synergy patterns to produce functional motor outputs across different biomechanical conditions, which we define as generalizability. Experimental studies in cats demonstrate that the same muscle synergies are used during reactive postural responses at widely varying configurations, producing similarly-oriented endpoint force vectors with respect to the limb axis. However, whether generalizability across postures arises due to similar biomechanical properties or to neural selection of a particular muscle activation pattern has not been explicitly tested. Here, we used a detailed cat hindlimb model to explore the set of feasible muscle activation patterns that produce experimental synergy force vectors at a target posture, and tested their generalizability by applying them to different test postures. We used three methods to select candidate muscle activation patterns: (1) randomly-selected feasible muscle activation patterns, (2) optimal muscle activation patterns minimizing muscle effort at a given posture, and (3) generalizable muscle activation patterns that explicitly minimized deviations from experimentally-identified synergy force vectors across all postures. Generalizability was measured by the deviation between the simulated force direction of the candidate muscle activation pattern and the experimental synergy force vectors at the test postures. Force angle deviations were the greatest for the randomly selected feasible muscle activation patterns (e.g., >100°), intermediate for effort-wise optimal muscle activation patterns (e.g., ~20°), and smallest for generalizable muscle activation patterns (e.g., synergy force vector was reduced by ~45% when generalizability requirements were imposed. Muscles recruited in the generalizable muscle activation patterns had less sensitive torque-producing characteristics to changes in postures. We

  9. Structure and function of masticatory muscles in a case of muscular dystrophy

    DEFF Research Database (Denmark)

    Bakke, M; Kirkeby, S; Jensen, B L

    1990-01-01

    Histologic examination of muscle biopsies and functional examination comprising electromyography and force measurements in a 19-yr-old boy with muscular dystrophy showed different wasting patterns of mandibular elevator and depressor muscles. Pronounced histopathologic changes were present...... depressor strength corresponded more to reference values. This difference of muscular wasting might be caused by protective enzymes in the digastric muscle and/or functionally induced damage of the masseter. As affection from muscular dystrophy may vary greatly between the masticatory muscles, structural...... in the masseter muscle, whereas pathologic findings in the anterior digastric muscle were limited to increased number of cells in slightly enlarged interfiber connective tissue. The masticatory pattern was distorted, and strength of mandibular elevator muscles was less than one third of the norm, whereas...

  10. Influence of temperature on muscle recruitment and muscle function in vivo.

    Science.gov (United States)

    Rome, L C

    1990-08-01

    Temperature has a large influence on the maximum velocity of shortening (Vmax) and maximum power output of muscle (Q10 = 1.5-3). In some animals, maximum performance and maximum sustainable performance show large temperature sensitivities, because these parameters are dependent solely on mechanical power output of the muscles. The mechanics of locomotion (sarcomere length excursions and muscle-shortening velocities, V) at a given speed, however, are precisely the same at all temperatures. Animals compensate for the diminished power output of their muscles at low temperatures by compressing their recruitment order into a narrower range of locomotor speeds, that is, recruiting more muscle fibers and faster fiber types at a given speed. By examining V/Vmax, I calculate that fish at 10 degrees C must recruit 1.53-fold greater fiber cross section than at 20 degrees C. V/Vmax also appears to be an important design constraint in muscle. It sets the lowest V and the highest V over which a muscle can be used effectively. Because the Vmax of carp slow red muscle has a Q10 of 1.6 between 10 and 20 degrees C, the slow aerobic fibers can be used over a 1.6-fold greater range of swim speeds at the warmer temperature. In some species of fish, Vmax can be increased during thermal acclimation, enabling animals to swim at higher speeds.

  11. Tapping but not massage enhances vasodilation and improves venous palpation of cutaneous veins.

    Science.gov (United States)

    Ichimura, Mika; Sasaki, Shinsuke; Mori, Masaharu; Ogino, Tetsuya

    2015-01-01

    This paper investigated whether tapping on the median cubital vein or massaging the forearm was more effective in obtaining better venous palpation for venipuncture. Forty healthy volunteers in their twenties were subjected to tapping (10 times in 5 sec) or massage (10 strokes in 20 sec from the wrist to the cubital fossa) under tourniquet inflation on the upper arm. Venous palpation was assessed using the venous palpation score (0-6, with 0 being impalpable). Three venous factors-venous depth, cross-sectional area, and elevation-were also measured using ultrasonography. The venous palpation score increased significantly by tapping but not by massage. Moreover, all 3 venous measurements changed significantly by tapping, while only the depth decreased significantly by massage. The three venous measurements correlated significantly with the venous palpation score, indicating that they are useful objective indicators for evaluating vasodilation. We suggest that tapping is an effective vasodilation technique.

  12. Functional connectivity between core and shoulder muscles increases during isometric endurance contractions in judo competitors

    DEFF Research Database (Denmark)

    Kawczyński, Adam; Samani, Afshin; Mroczek, Dariusz

    2015-01-01

    endurance contraction consisting of bilateral arm abduction at 90°. The normalized mutual information (NMI) was computed between muscle pairs as an index indicating functional connectivity. Results: The NMIs increased significantly during endurance test for 10 of the 15 muscle pairs (P ... : We concluded that the increases in NMIs highlighted functional changes in the interplay between core and shoulder muscles during an endurance contraction in elite judokas....

  13. Muscle biopsies from human muscle diseases with myopathic pathology reveal common alterations in mitochondrial function.

    Science.gov (United States)

    Sunitha, Balaraju; Gayathri, Narayanappa; Kumar, Manish; Keshava Prasad, Thottethodi Subrahmanya; Nalini, Atchayaram; Padmanabhan, Balasundaram; Srinivas Bharath, Muchukunte Mukunda

    2016-07-01

    Muscle diseases are clinically and genetically heterogeneous and manifest as dystrophic, inflammatory and myopathic pathologies, among others. Our previous study on the cardiotoxin mouse model of myodegeneration and inflammation linked muscle pathology with mitochondrial damage and oxidative stress. In this study, we investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from muscle disease patients, represented by dysferlinopathy (dysfy) (dystrophic pathology; n = 43), polymyositis (PM) (inflammatory pathology; n = 24), and distal myopathy with rimmed vacuoles (DMRV) (distal myopathy; n = 31) were analyzed. Mitochondrial damage (ragged blue and COX-deficient fibers) was revealed in dysfy, PM, and DMRV cases by enzyme histochemistry (SDH and COX-SDH), electron microscopy (vacuolation and altered cristae) and biochemical assays (significantly increased ADP/ATP ratio). Proteomic analysis of muscle mitochondria from all three muscle diseases by isobaric tag for relative and absolute quantitation labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated down-regulation of electron transport chain (ETC) complex subunits, assembly factors and Krebs cycle enzymes. Interestingly, 80 of the under-expressed proteins were common among the three pathologies. Assay of ETC and Krebs cycle enzyme activities validated the MS data. Mitochondrial proteins from muscle pathologies also displayed higher tryptophan (Trp) oxidation and the same was corroborated in the cardiotoxin model. Molecular modeling predicted Trp oxidation to alter the local structure of mitochondrial proteins. Our data highlight mitochondrial alterations in muscle pathologies, represented by morphological changes, altered mitochondrial proteome and protein oxidation, thereby establishing the role of mitochondrial damage in human muscle diseases. We investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies

  14. Functional ability and muscle force in healthy children and ambulant Duchenne muscular dystrophy patients

    NARCIS (Netherlands)

    Beenakker, EAC; Maurits, NM; Fock, JM; Brouwer, OF; van der Hoeven, JH

    2005-01-01

    Neuromuscular disorders are characterised by progressive muscle weakness, which in time causes functional impairment. To quantify the extent of disease progression, muscle force and functional ability can be measured. Which of these parameters changes most depends on the disease stage. In a previous

  15. The morphology and functions of the muscles around the hip joint after a unilateral transfemoral amputation

    NARCIS (Netherlands)

    Jaegers, Sonja Maria Héléne José

    1993-01-01

    This dissertation is concerned with the consequences of a transfemoral amputation for the morphology and functions of the muscles around the hip joint. Knowledge about and insight into the changes appearing in the morphology and functions of the hip muscles of transfemoral amputees are important to

  16. Contribution of elastic tissues to the mechanics and energetics of muscle function during movement.

    Science.gov (United States)

    Roberts, Thomas J

    2016-01-01

    Muscle force production occurs within an environment of tissues that exhibit spring-like behavior, and this elasticity is a critical determinant of muscle performance during locomotion. Muscle force and power output both depend on the speed of contraction, as described by the isotonic force-velocity curve. By influencing the speed of contractile elements, elastic structures can have a profound effect on muscle force, power and work. In very rapid movements, elastic mechanisms can amplify muscle power by storing the work of muscle contraction slowly and releasing it rapidly. When energy must be dissipated rapidly, such as in landing from a jump, energy stored rapidly in elastic elements can be released more slowly to stretch muscle contractile elements, reducing the power input to muscle and possibly protecting it from damage. Elastic mechanisms identified so far rely primarily on in-series tendons, but many structures within muscles exhibit spring-like properties. Actomyosin cross-bridges, actin and myosin filaments, titin, and the connective tissue scaffolding of the extracellular matrix all have the potential to store and recover elastic energy during muscle contraction. The potential contribution of these elements can be assessed from their stiffness and estimates of the strain they undergo during muscle function. Such calculations provide boundaries for the possible roles these springs might play in locomotion, and may help to direct future studies of the uses of elastic elements in muscle. © 2016. Published by The Company of Biologists Ltd.

  17. Skeletal muscle function and hypertrophy are diminished in old age.

    NARCIS (Netherlands)

    Degens, H.; Alway, S.E.

    2003-01-01

    Muscle loss occurs during aging. To investigate whether the hypertrophic response is attenuated at old age, we used male Fischer 344 (26 months old; n = 5) and Fischer 344 x Brown Norway rats (6, 9, and 33 months old; n = 8, 10, and 6, respectively). Hypertrophy of the left plantaris muscle was

  18. Histochemical and functional fibre typing of the rabbit masseter muscle

    NARCIS (Netherlands)

    Bredman, J. J.; Weijs, W. A.; Moorman, A. F.; Brugman, P.

    1990-01-01

    The fibre-type distribution of the masseter muscle of the rabbit was studied by means of the myosin-ATPase and succinate dehydrogenase reactions. Six different fibre types were found and these were unequally distributed between and within the anatomical compartments of the muscle. Most of the

  19. Comparison of muscle/lean mass measurement methods: correlation with functional and biochemical testing.

    Science.gov (United States)

    Buehring, B; Siglinsky, E; Krueger, D; Evans, W; Hellerstein, M; Yamada, Y; Binkley, N

    2018-03-01

    DXA-measured lean mass is often used to assess muscle mass but has limitations. Thus, we compared DXA lean mass with two novel methods-bioelectric impedance spectroscopy and creatine (methyl-d3) dilution. The examined methodologies did not measure lean mass similarly and the correlation with muscle biomarkers/function varied. Muscle function tests predict adverse health outcomes better than lean mass measurement. This may reflect limitations of current mass measurement methods. Newer approaches, e.g., bioelectric impedance spectroscopy (BIS) and creatine (methyl-d3) dilution (D3-C), may more accurately assess muscle mass. We hypothesized that BIS and D3-C measured muscle mass would better correlate with function and bone/muscle biomarkers than DXA measured lean mass. Evaluations of muscle/lean mass, function, and serum biomarkers were obtained in older community-dwelling adults. Mass was assessed by DXA, BIS, and orally administered D3-C. Grip strength, timed up and go, and jump power were examined. Potential muscle/bone serum biomarkers were measured. Mass measurements were compared with functional and serum data using regression analyses; differences between techniques were determined by paired t tests. Mean (SD) age of the 112 (89F/23M) participants was 80.6 (6.0) years. The lean/muscle mass assessments were correlated (.57-.88) but differed (p Lean mass measures were unrelated to the serum biomarkers measured. These three methodologies do not similarly measure muscle/lean mass and should not be viewed as being equivalent. Functional tests assessing maximal muscle strength/power (grip strength and jump power) correlated with all mass measures whereas gait speed was not. None of the selected serum measures correlated with mass. Efforts to optimize muscle mass assessment and identify their relationships with health outcomes are needed.

  20. Relationships of Muscle Function and Subjective Knee Function in Patients After ACL Reconstruction.

    Science.gov (United States)

    Bodkin, Stephan; Goetschius, John; Hertel, Jay; Hart, Joe

    2017-07-01

    After anterior cruciate ligament reconstruction (ACLR), relationships between objective measures of muscle function and patient-reported outcomes may change over time. Examining these measures at different time frames after surgery may help develop individualized approaches to improve post-ALCR analysis. To examine the associations between subjective knee function and lower-extremity muscle function in individual patients at various time points after ACLR. Descriptive laboratory study. Fifty-one participants who underwent primary, unilateral ACLR (15 males, 36 females; mean age, 22.9 ± 4.5 years; mean height, 172.4 ± 10.1 cm; mean weight, 68.7 ± 13.1 kg) were separated into 3 groups depending on time since surgery (early, 5 years). Subjective knee function was quantified using the International Knee Documentation Committee (IKDC) subjective knee form and the Knee injury and Osteoarthritis Outcome Score (KOOS). Isometric knee extension and flexion strength were collected at 90 deg/s. Single-leg hop performance was measured using the single hop, triple hop, cross-over hop, and 6-m timed hop. Coefficient correlations were calculated between subjective knee function and objective measures of muscle function for each group. The early group demonstrated moderate correlations between the KOOS and unilateral measures of flexion peak torque ( r = 0.514, P = .035) and flexion power ( r = 0.54, P = .027). The middle group demonstrated the strongest correlations between the KOOS and symmetry measures of the single hop ( r = 0.69, P = .002) and extension work ( r = 0.71, P = .002) as well as unilateral measures of the triple hop ( r = 0.52, P = .034) and extension work ( r = 0.66, P = .004). The late group demonstrated strong correlations between the 6-m timed hop symmetry and the IKDC ( r = 0.716, P = .001) and KOOS ( r = 0.71, P = .001). Patients with a post-ACLR status of less than 2 years exhibited stronger relationships with unilateral strength measures to subjective

  1. Assessment of muscle function using hybrid PET/MRI

    DEFF Research Database (Denmark)

    Haddock, Bryan; Holm, Søren; Poulsen, Jákup M.

    2017-01-01

    -FDG while activating the quadriceps of one leg with repeated knee extension exercises followed by hand-grip exercises for one arm. Immediately following the exercises, the subjects were scanned simultaneously with 18F-FDG PET/MRI and muscle groups were evaluated for increases in 18F-FDG uptake and MRI T2......Purpose: The aim of this study was to determine the relationship between relative glucose uptake and MRI T2 changes in skeletal muscles following resistance exercise using simultaneous PET/MRI scans. Methods: Ten young healthy recreationally active men (age 21 – 28 years) were injected with 18F...... values. Results: A significant linear correlation between 18F-FDG uptake and changes in muscle T2 (R2 = 0.71) was found. for both small and large muscles and in voxel to voxel comparisons. Despite large intersubject differences in muscle recruitment, the linear correlation between 18F-FDG uptake...

  2. Epidemiological investigation of muscle-strengthening activities and cognitive function among older adults.

    Science.gov (United States)

    Loprinzi, Paul D

    2016-06-01

    Limited research has examined the association of muscle-strengthening activities and executive cognitive function among older adults, which was this study's purpose. Data from the 1999-2002 NHANES were employed (N = 2157; 60-85 years). Muscle-strengthening activities were assessed via self-report, with cognitive function assessed using the digit symbol substitution test. After adjusting for age, age-squared, gender, race-ethnicity, poverty level, body mass index, C-reactive protein, smoking, comorbid illness and physical activity, muscle-strengthening activities were significantly associated with cognitive function (βadjusted = 3.4; 95% CI: 1.7-5.1; P cognitive function score. In conclusion, muscle-strengthening activities are associated with executive cognitive function among older U.S. adults, underscoring the importance of promoting both aerobic exercise and muscle-strengthening activities to older adults. © The Author(s) 2016.

  3. Differential activation of an identified motor neuron and neuromodulation provide Aplysia's retractor muscle an additional function.

    Science.gov (United States)

    McManus, Jeffrey M; Lu, Hui; Cullins, Miranda J; Chiel, Hillel J

    2014-08-15

    To survive, animals must use the same peripheral structures to perform a variety of tasks. How does a nervous system employ one muscle to perform multiple functions? We addressed this question through work on the I3 jaw muscle of the marine mollusk Aplysia californica's feeding system. This muscle mediates retraction of Aplysia's food grasper in multiple feeding responses and is innervated by a pool of identified neurons that activate different muscle regions. One I3 motor neuron, B38, is active in the protraction phase, rather than the retraction phase, suggesting the muscle has an additional function. We used intracellular, extracellular, and muscle force recordings in several in vitro preparations as well as recordings of nerve and muscle activity from intact, behaving animals to characterize B38's activation of the muscle and its activity in different behavior types. We show that B38 specifically activates the anterior region of I3 and is specifically recruited during one behavior, swallowing. The function of this protraction-phase jaw muscle contraction is to hold food; thus the I3 muscle has an additional function beyond mediating retraction. We additionally show that B38's typical activity during in vivo swallowing is insufficient to generate force in an unmodulated muscle and that intrinsic and extrinsic modulation shift the force-frequency relationship to allow contraction. Using methods that traverse levels from individual neuron to muscle to intact animal, we show how regional muscle activation, differential motor neuron recruitment, and neuromodulation are key components in Aplysia's generation of multifunctionality. Copyright © 2014 the American Physiological Society.

  4. Structural, biochemical, cellular, and functional changes in skeletal muscle extracellular matrix with aging

    DEFF Research Database (Denmark)

    Kragstrup, Tue Wenzel; Kjaer, M; Mackey, A L

    2011-01-01

    The extracellular matrix (ECM) of skeletal muscle is critical for force transmission and for the passive elastic response of skeletal muscle. Structural, biochemical, cellular, and functional changes in skeletal muscle ECM contribute to the deterioration in muscle mechanical properties with aging......-links and a buildup of advanced glycation end-product cross-links. Altered mechanotransduction, poorer activation of satellite cells, poorer chemotactic and delayed inflammatory responses, and a change in modulators of the ECM are important cellular changes. It is possible that the structural and biochemical changes...... in skeletal muscle ECM contribute to the increased stiffness and impairment in force generated by the contracting muscle fibers seen with aging. The cellular interactions provide and potentially coordinate an adaptation to mechanical loading and ensure successful regeneration after muscle injury. Some...

  5. Whole-muscle reimplantation with microneurovascular anastomoses. A functional and histological study.

    Science.gov (United States)

    Prendergast, F. J.; McGeachie, J. K.; Edis, R. H.; Allbrook, D.

    1977-01-01

    Whole tibialis anterior muscles were removed from a number of dogs and were then reimplanted in the original sites. Microsurgical anastomoses of the major nerve, artery, and vein were performed. Biopsy revealed some minor regenerative changes in the muscle a few weeks after the operation. Electromyographic recordings 6-9 months after implantation showed near-complete functional recovery of the muscles. This was confirmed histologically. The study demonstrates not only that whole-muscle reimplantation is technically feasible but that a functionally satisfactory result may be expected. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 PMID:900796

  6. Impaired Arterial Smooth Muscle Cell Vasodilatory Function In Methamphetamine Users

    Directory of Open Access Journals (Sweden)

    Ghaemeh Nabaei

    2017-02-01

    Full Text Available Objectives: Methamphetamine use is a strong risk factor for stroke. This study was designed to evaluate arterial function and structure in methamphetamine users ultrasonographically. Methods: In a cross-sectional study, 20 methamphetamine users and 21 controls, aged between 20 and 40years, were enrolled. Common carotid artery intima-media thickness (CCA-IMT marker of early atherogenesis, flow-mediated dilatation (FMD determinants of endothelium-dependent vasodilation, and nitroglycerine-mediated dilatation (NMD independent marker of vasodilation were measured in two groups. Results: There were no significant differences between the two groups regarding demographic and metabolic characteristics. The mean (±SD CCA-IMT in methamphetamine users was 0.58±0.09mm, versus 0.59±0.07mm in the controls (p=0.84. Likewise, FMD% was not significantly different between the two groups [7.6±6.1% in methamphetamine users vs. 8.2±5.1% in the controls; p=0.72], nor were peak flow and shear rate after hyperemia. However, NMD% was considerably decreased in the methamphetamine users [8.5±7.8% in methamphetamine users vs. 13.4±6.2% in controls; p=0.03]. Conclusion: According to our results, NMD is reduced among otherwise healthy methamphetamine users, which represents smooth muscle dysfunction in this group. This may contribute to the high risk of stroke among methamphetamine users.

  7. A study on the relationship between muscle function, functional mobility and level of physical activity in community-dwelling elderly.

    Science.gov (United States)

    Garcia, Patrícia A; Dias, João M D; Dias, Rosângela C; Santos, Priscilla; Zampa, Camila C

    2011-01-01

    to evaluate the relationship between lower extremity muscle function, calf circumference (CC), handgrip strength (HG), functional mobility and level of physical activity among age groups (65-69, 70-79, 80+) of older adults (men and women) and to identify the best parameter for screening muscle function loss in the elderly. 81 community-dwelling elderly (42 women and 39 men) participated. Walking speed (Multisprint Kit), HG (Jamar dynamometer), hip, knee and ankle muscle function (Biodex isokinetic dynamometer), level of physical activity (Human Activity Profile) and CC (tape measure) were evaluated. ANOVA, Pearson correlation and ROC curves were used for statistical analysis. Dominant CC (34.9±3 vs 37.7±3.6), habitual (1.1±0.2 vs 1.2±0.2) and fast (1.4±0.3 vs 1.7±0.3) walking speed, HG (23.8±7.5 vs 31.8±10.3), average peak torque and average hip, knee and ankle power (pphysical activity level among age groups. Moderate significant correlations were found between muscle function parameters, walking speed and HG; a fair degree of relationship was found between muscle function parameters, CC and level of physical activity (pwomen (p=0.03). This study demonstrated an association between muscle function, HG and fast walking speed, a decrease in these parameters with age and the possibility of using HG to screen for muscle function of the lower extremities.

  8. Respiratory muscle function and exercise limitation in patients with chronic obstructive pulmonary disease: a review.

    Science.gov (United States)

    Charususin, Noppawan; Dacha, Sauwaluk; Gosselink, Rik; Decramer, Marc; Von Leupoldt, Andreas; Reijnders, Thomas; Louvaris, Zafeiris; Langer, Daniel

    2018-01-01

    Respiratory muscle dysfunction is common and contributes to dyspnea and exercise limitation in patients with chronic obstructive pulmonary disease (COPD). Improving dynamic function of respiratory muscles during exercise might help to reduce symptoms and improve exercise capacity. Areas covered: The aims of this review are to 1) summarize physiological mechanisms linking respiratory muscle dysfunction to dyspnea and exercise limitation; 2) provide an overview of available therapeutic approaches to better maintain load-capacity balance of respiratory muscles during exercise; and 3) to summarize current knowledge on potential mechanisms explaining effects of interventions aimed at optimizing dynamic respiratory muscle function with a special focus on inspiratory muscle training. Expert commentary: Several mechanisms which are potentially linking improvements in dynamic respiratory muscle function to symptomatic and functional benefits have not been studied so far in COPD patients. Examples of underexplored areas include the study of neural processes related to the relief of acute dyspnea and the competition between respiratory and peripheral muscles for limited energy supplies during exercise. Novel methodologies are available to non-invasively study these mechanisms. Better insights into the consequences of dynamic respiratory muscle dysfunction will hopefully contribute to further refine and individualize therapeutic approaches in patients with COPD.

  9. Functional muscle ischemia in Duchenne and Becker muscular dystrophy

    OpenAIRE

    Thomas, Gail D.

    2013-01-01

    Duchenne and Becker muscular dystrophy (DMD/BMD) comprise a spectrum of devastating X-linked muscle wasting disease for which there is no treatment. DMD/BMD is caused by mutations in the gene encoding dystrophin, a cytoskeletal protein that stabilizes the muscle membrane and also targets other proteins to the sarcolemma. Among these is the muscle-specific isoform of neuronal nitric oxide synthase (nNOSµ) which binds spectrin-like repeats within dystrophin’s rod domain and the adaptor pro...

  10. Phosphorylation and function of DGAT1 in skeletal muscle cells

    OpenAIRE

    Yu, Jinhai; Li, Yiran; Zou, Fei; Xu, Shimeng; Liu, Pingsheng

    2015-01-01

    Aberrant intramuscular triacylglycerol (TAG) storage in human skeletal muscle is closely related to insulin insensitivity. Excessive lipid storage can induce insulin resistance of skeletal muscle, and under severe conditions, lead to type 2 diabetes. The balance of interconversion between diacylglycerol and TAG greatly influences lipid storage and utilization. Diacylglycerol O-acyltransferase 1 (DGAT1) plays a key role in this process, but its activation and phosphorylation requires further d...

  11. Vitamin D and muscle function in the elderly: the elixir of youth?

    Science.gov (United States)

    Girgis, Christian M

    2014-11-01

    Circumstantial evidence suggests that vitamin D deficiency may contribute to age-related changes in skeletal muscle. This review discusses recent clinical trials examining effects of vitamin D on muscle function in the elderly, and poses the important question: can vitamin D reverse muscle ageing? Observational studies report an association between vitamin D and muscle atrophy/weakness in elderly subjects. Interventional studies suggest that frail, elderly subjects may benefit from vitamin D supplementation by displaying reduced falls, improved muscle function and increased muscle fibre size. However, meta-analyses do not report convincing effects of vitamin D in the elderly. This may be because of multiple factors including lack of standardized endpoints for muscle function, variable study design and different doses of vitamin D supplementation amongst these studies. The evidence base is therefore inconsistent. Vitamin D deficiency may exacerbate ageing of skeletal muscle. However, current evidence that vitamin D supplementation reverses age-related muscle dysfunction is equivocal and does not justify stringent vitamin D targets in the elderly. Until these issues are clarified, the safest option is to aim for conservative vitamin D targets that are sufficient for normal calcium homeostasis.

  12. Muscle power is an important measure to detect deficits in muscle function in hip osteoarthritis: a cross-sectional study.

    Science.gov (United States)

    Bieler, Theresa; Magnusson, Stig Peter; Christensen, Helle Elisabeth; Kjaer, Michael; Beyer, Nina

    2017-07-01

    To investigate between-leg differences in hip and thigh muscle strength and leg extensor power in patients with unilateral hip osteoarthritis. Further, to compare between-leg differences in knee extensor strength and leg extensor power between patients and healthy peers. Seventy-two patients (60-87 years) with radiographic and symptomatic hip osteoarthritis not awaiting hip replacement and 35 healthy peers (63-82 years) were included. Hip and thigh muscle strength and leg extensor power were measured in patients and knee extensor strength and leg extensor power in healthy. The symptomatic extremity in patients was significantly (p hip muscles (8-17%), knee extensors (11%) and leg extensor power (19%). Healthy older adults had asymmetry in knee extensor strength (6%, p hip osteoarthritis. Implications for Rehabilitation Even in patients with mild symptoms not awaiting hip replacement a generalized muscle weakening of the symptomatic lower extremity seems to be present. Between-leg differences in leg extensor power (force × velocity) appears to be relatively large (19%) in patients with unilateral hip osteoarthritis in contrast to healthy peers who show no asymmetry. Compared to muscle strength the relationship between functional performance and leg extensor power seems to be stronger, and more strongly related to power of the symptomatic lower extremity. Our results indicate that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with mild symptoms not awaiting hip replacement.

  13. AMPKγ3 is dispensable for skeletal muscle hypertrophy induced by functional overload.

    Science.gov (United States)

    Riedl, Isabelle; Osler, Megan E; Björnholm, Marie; Egan, Brendan; Nader, Gustavo A; Chibalin, Alexander V; Zierath, Juleen R

    2016-03-15

    Mechanisms regulating skeletal muscle growth involve a balance between the activity of serine/threonine protein kinases, including the mammalian target of rapamycin (mTOR) and 5'-AMP-activated protein kinase (AMPK). The contribution of different AMPK subunits to the regulation of cell growth size remains inadequately characterized. Using AMPKγ3 mutant-overexpressing transgenic Tg-Prkag3(225Q) and AMPKγ3-knockout (Prkag3(-/-)) mice, we investigated the requirement for the AMPKγ3 isoform in functional overload-induced muscle hypertrophy. Although the genetic disruption of the γ3 isoform did not impair muscle growth, control sham-operated AMPKγ3-transgenic mice displayed heavier plantaris muscles in response to overload hypertrophy and underwent smaller mass gain and lower Igf1 expression compared with wild-type littermates. The mTOR signaling pathway was upregulated with functional overload but unchanged between genetically modified animals and wild-type littermates. Differences in AMPK-related signaling pathways between transgenic, knockout, and wild-type mice did not impact muscle hypertrophy. Glycogen content was increased following overload in wild-type mice. In conclusion, our functional, transcriptional, and signaling data provide evidence against the involvement of the AMPKγ3 isoform in the regulation of skeletal muscle hypertrophy. Thus, the AMPKγ3 isoform is dispensable for functional overload-induced muscle growth. Mechanical loading can override signaling pathways that act as negative effectors of mTOR signaling and consequently promote skeletal muscle hypertrophy. Copyright © 2016 the American Physiological Society.

  14. Musculoskeletal Geometry, Muscle Architecture and Functional Specialisations of the Mouse Hindlimb (Open Access)

    Science.gov (United States)

    2016-04-26

    example, studies in cats [18], guinea pigs [16] and rabbits [19] have shown that the hamstring muscles, a bi-articular group of muscles which act around...energy in compliant tendons [20, 21], whereas others, such as the hamstrings (hip extensors and knee flexors), function to produce fast contractions

  15. Image guided versus palpation guided core needle biopsy of palpable breast masses: a prospective study

    Directory of Open Access Journals (Sweden)

    Smriti Hari

    2016-01-01

    Interpretation & conclusions: Our results showed that in palpable breast masses, image guided biopsy was superior to palpation guided biopsy in terms of sensitivity, false negative rate and repeat biopsy rates.

  16. Association between composites of selected motion palpation and pain provocation tests for sacroiliac joint disorders.

    Science.gov (United States)

    Soleimanifar, Manijeh; Karimi, Noureddin; Arab, Amir Massoud

    2017-04-01

    The sacroiliac joint (SIJ) has been implicated as a potential source of low back and buttock pain. Several types of motion palpation and pain provocation tests are used to evaluate SIJ dysfunction. The purpose of this study was to investigate the relationship between motion palpation and pain provocation tests in assessment of SIJ problems. This study is Descriptive Correlation. 50 patients between the ages of 20 and 65 participated. Four motion palpation tests (Sitting flexion, Standing flexion, Prone knee flexion, Gillet test) and three pain provocation tests (FABER, Posterior shear, Resisted abduction test) were examined. Chi-square analysis was used to assess the relationship between results of the individuals and composites of these two groups of tests. No significant relationship was found between these two groups of tests. It seems that motion palpation tests assess SIJ dysfunction and provocative tests assessed SIJ pain which do not appear to be related. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Physical activity as intervention for age-related loss of muscle mass and function

    DEFF Research Database (Denmark)

    Eriksen, Christian Skou; Garde, Ellen; Reislev, Nina Linde

    2016-01-01

    insights into training-induced promotion of functional ability and independency after retirement and will help to formulate national recommendations regarding physical activity schemes for the growing population of older individuals in western societies. Results will be published in scientific peer......INTRODUCTION: Physical and cognitive function decline with age, accelerating during the 6th decade. Loss of muscle power (force×velocity product) is a dominant physical determinant for loss of functional ability, especially if the lower extremities are affected. Muscle strength training is known...... to maintain or even improve muscle power as well as physical function in older adults, but the optimal type of training for beneficial long-term training effects over several years is unknown. Moreover, the impact of muscle strength training on cognitive function and brain structure remains speculative...

  18. Hsp72 preserves muscle function and slows progression of severe muscular dystrophy.

    Science.gov (United States)

    Gehrig, Stefan M; van der Poel, Chris; Sayer, Timothy A; Schertzer, Jonathan D; Henstridge, Darren C; Church, Jarrod E; Lamon, Severine; Russell, Aaron P; Davies, Kay E; Febbraio, Mark A; Lynch, Gordon S

    2012-04-04

    Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder caused by mutations in the dystrophin gene that result in the absence of the membrane-stabilizing protein dystrophin. Dystrophin-deficient muscle fibres are fragile and susceptible to an influx of Ca(2+), which activates inflammatory and muscle degenerative pathways. At present there is no cure for DMD, and existing therapies are ineffective. Here we show that increasing the expression of intramuscular heat shock protein 72 (Hsp72) preserves muscle strength and ameliorates the dystrophic pathology in two mouse models of muscular dystrophy. Treatment with BGP-15 (a pharmacological inducer of Hsp72 currently in clinical trials for diabetes) improved muscle architecture, strength and contractile function in severely affected diaphragm muscles in mdx dystrophic mice. In dko mice, a phenocopy of DMD that results in severe spinal curvature (kyphosis), muscle weakness and premature death, BGP-15 decreased kyphosis, improved the dystrophic pathophysiology in limb and diaphragm muscles and extended lifespan. We found that the sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA, the main protein responsible for the removal of intracellular Ca(2+)) is dysfunctional in severely affected muscles of mdx and dko mice, and that Hsp72 interacts with SERCA to preserve its function under conditions of stress, ultimately contributing to the decreased muscle degeneration seen with Hsp72 upregulation. Treatment with BGP-15 similarly increased SERCA activity in dystrophic skeletal muscles. Our results provide evidence that increasing the expression of Hsp72 in muscle (through the administration of BGP-15) has significant therapeutic potential for DMD and related conditions, either as a self-contained therapy or as an adjuvant with other potential treatments, including gene, cell and pharmacological therapies.

  19. Lack of Glycogenin Causes Glycogen Accumulation and Muscle Function Impairment.

    Science.gov (United States)

    Testoni, Giorgia; Duran, Jordi; García-Rocha, Mar; Vilaplana, Francisco; Serrano, Antonio L; Sebastián, David; López-Soldado, Iliana; Sullivan, Mitchell A; Slebe, Felipe; Vilaseca, Marta; Muñoz-Cánoves, Pura; Guinovart, Joan J

    2017-07-05

    Glycogenin is considered essential for glycogen synthesis, as it acts as a primer for the initiation of the polysaccharide chain. Against expectations, glycogenin-deficient mice (Gyg KO) accumulate high amounts of glycogen in striated muscle. Furthermore, this glycogen contains no covalently bound protein, thereby demonstrating that a protein primer is not strictly necessary for the synthesis of the polysaccharide in vivo. Strikingly, in spite of the higher glycogen content, Gyg KO mice showed lower resting energy expenditure and less resistance than control animals when subjected to endurance exercise. These observations can be attributed to a switch of oxidative myofibers toward glycolytic metabolism. Mice overexpressing glycogen synthase in the muscle showed similar alterations, thus indicating that this switch is caused by the excess of glycogen. These results may explain the muscular defects of GSD XV patients, who lack glycogenin-1 and show high glycogen accumulation in muscle. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. A physiologically based, multi-scale model of skeletal muscle structure and function

    Directory of Open Access Journals (Sweden)

    Oliver eRöhrle

    2012-09-01

    Full Text Available Models of skeletal muscle can be classified as phenomenological or biophysical. Phenomenological models predict the muscle's response to a specified input based on experimental measurements. Prominent phenomenological models are the Hill-type muscle models, which have been incorporated into rigid-body modelling frameworks, and three-dimensional continuum-mechanical models. Biophysically based models attempt to predict the muscle's response as emerging from the underlying physiology of the system. In this contribution, the conventional biophysically based modelling methodology is extended to include several structural and functional characteristics of skeletal muscle. The result is a physiologically based, multi-scale skeletal muscle finite element model that is capable of representing detailed, geometrical descriptions of skeletal muscle fibres and their grouping. Together with a well-established model of motor unit recruitment, the electro-physiological behaviour of single muscle fibres within motor units is computed and linked to a continuum-mechanical constitutive law. The bridging between the cellular level and the organ level has been achieved via a multi-scale constitutive law and homogenisation. The effect of homogenisation has been investigated by varying the number of embedded skeletal muscle fibres and/or motor units and computing the resulting exerted muscle forces while applying the same excitatory input. All simulations were conducted using an anatomically realistic finite element model of the Tibialis Anterior muscle. Given the fact that the underlying electro-physiological cellular muscle model is capable of modelling metabolic fatigue effects such as potassium accumulation in the T-tubular space and inorganic phosphate build-up, the proposed framework provides a novel simulation-based way to investigate muscle behaviour ranging from motor unit recruitment to force generation and fatigue.

  1. Effects of isokinetic calf muscle exercise program on muscle strength and venous function in patients with chronic venous insufficiency.

    Science.gov (United States)

    Ercan, Sabriye; Çetin, Cem; Yavuz, Turhan; Demir, Hilmi M; Atalay, Yurdagül B

    2018-05-01

    Objective The aim of this study was to observe the change of the ankle joint range of motion, the muscle strength values measured with an isokinetic dynamometer, pain scores, quality of life scale, and venous return time in chronic venous insufficiency diagnosed patients by prospective follow-up after 12-week exercise program including isokinetic exercises. Methods The patient group of this study comprised 27 patients (23 female, 4 male) who were diagnosed with chronic venous insufficiency. An exercise program including isokinetic exercise for the calf muscle was given to patients three days per week for 12 weeks. At the end of 12 weeks, five of the patients left the study due to inadequate compliance with the exercise program. As a result, control data of 22 patients were included. Ankle joint range of active motion, isokinetic muscle strength, pain, quality of life, and photoplethysmography measurements were assessed before starting and after the exercise program. Results Evaluating changes of the starting and control data depending on time showed that all isokinetic muscle strength measurement parameters, range of motion, and overall quality of life values of patients improved. Venous return time values have also increased significantly ( p < 0.05). Conclusion In conclusion, increase in muscle strength has been provided with exercise therapy in patients with chronic venous insufficiency. It has been determined that the increase in muscle strength affected the venous pump and this ensured improvement in venous function and range of motion of the ankle. In addition, it has been detected that pain reduced and quality of life improved after the exercise program.

  2. Changes in the Muscle strength and functional performance of healthy women with aging

    Directory of Open Access Journals (Sweden)

    Roghayeh Mousavikhatir

    2012-08-01

    Full Text Available Abstract Background: Lower limbs antigravity muscles weakness and decreased functional ability have significant role in falling. The aim of this study was to find the effects of aging on muscle strength and functional ability, determining the range of decreasing strength and functional ability and relationship between them in healthy women. Methods: Across-section study was performed on 101 healthy women aged 21-80 years. The participants were divided into six age groups. The maximum isometric strength of four muscle groups was measured using a hand-held dynamometer bilaterally. The functional ability was measured with functional reach (FR, timed get up and go (TGUG, single leg stance (SLS, and stairs walking (SW tests. Results: Muscle strength changes were not significant between 21-40 years of age, but decreased significantly thereafter. Also, there was a significant relationship between muscle strength and functional ability in age groups. Conclusion: Both muscle strength and functional ability is reduced as a result of aging, but the decrease in functional ability can be detected earlier.

  3. The Link between Dietary Protein Intake, Skeletal Muscle Function and Health in Older Adults

    Directory of Open Access Journals (Sweden)

    Jamie I. Baum

    2015-07-01

    Full Text Available Skeletal muscle mass and function are progressively lost with age, a condition referred to as sarcopenia. By the age of 60, many older adults begin to be affected by muscle loss. There is a link between decreased muscle mass and strength and adverse health outcomes such as obesity, diabetes and cardiovascular disease. Data suggest that increasing dietary protein intake at meals may counterbalance muscle loss in older individuals due to the increased availability of amino acids, which stimulate muscle protein synthesis by activating the mammalian target of rapamycin (mTORC1. Increased muscle protein synthesis can lead to increased muscle mass, strength and function over time. This review aims to address the current recommended dietary allowance (RDA for protein and whether or not this value meets the needs for older adults based upon current scientific evidence. The current RDA for protein is 0.8 g/kg body weight/day. However, literature suggests that consuming protein in amounts greater than the RDA can improve muscle mass, strength and function in older adults.

  4. [Correlations Between Joint Proprioception, Muscle Strength, and Functional Ability in Patients with Knee Osteoarthritis].

    Science.gov (United States)

    Chen, Yoa; Yu, Yong; He, Cheng-qi

    2015-11-01

    To establish correlations between joint proprioception, muscle flexion and extension peak torque, and functional ability in patients with knee osteoarthritis (OA). Fifty-six patients with symptomatic knee OA were recruited in this study. Both proprioceptive acuity and muscle strength were measured using the isomed-2000 isokinetic dynamometer. Proprioceptive acuity was evaluated by establishing the joint motion detection threshold (JMDT). Muscle strength was evaluated by Max torque (Nm) and Max torque/weight (Nm/ kg). Functional ability was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index physical function (WOMAC-PF) questionnaire. Correlational analyses were performed between proprioception, muscle strength, and functional ability. A multiple stepwise regression model was established, with WOMAC-PF as dependent variable and patient age, body mass index (BMI), visual analogue scale (VAS)-score, mean grade for Kellgren-Lawrance of both knees, mean strength for quadriceps and hamstring muscles of both knees, and mean JMDT of both knees as independent variables. Poor proprioception (high JMDT) was negatively correlated with muscle strength (Pcoefficient (B) = 0.385, P<0.50 and high VAS-scale score (B=0.347, P<0.05) were significant predictors of WOMAC-PF score. Patients with poor proprioception is associated with poor muscle strength and limitation in functional ability. Patients with symptomatic OA of knees commonly endure with moderate to considerable dysfunction, which is associated with poor proprioception (high JMDT) and high VAS-scale score.

  5. Cavin4b/Murcb Is Required for Skeletal Muscle Development and Function in Zebrafish.

    Science.gov (United States)

    Housley, Michael P; Njaine, Brian; Ricciardi, Filomena; Stone, Oliver A; Hölper, Soraya; Krüger, Marcus; Kostin, Sawa; Stainier, Didier Y R

    2016-06-01

    Skeletal muscles provide metazoans with the ability to feed, reproduce and avoid predators. In humans, a heterogeneous group of genetic diseases, termed muscular dystrophies (MD), lead to skeletal muscle dysfunction. Mutations in the gene encoding Caveolin-3, a principal component of the membrane micro-domains known as caveolae, cause defects in muscle maintenance and function; however it remains unclear how caveolae dysfunction underlies MD pathology. The Cavin family of caveolar proteins can form membrane remodeling oligomers and thus may also impact skeletal muscle function. Changes in the distribution and function of Cavin4/Murc, which is predominantly expressed in striated muscles, have been reported to alter caveolae structure through interaction with Caveolin-3. Here, we report the generation and phenotypic analysis of murcb mutant zebrafish, which display impaired swimming capacity, skeletal muscle fibrosis and T-tubule abnormalities during development. To understand the mechanistic importance of Murc loss of function, we assessed Caveolin-1 and 3 localization and found it to be abnormal. We further identified an in vivo function for Murc in Erk signaling. These data link Murc with developmental defects in T-tubule formation and progressive muscle dysfunction, thereby providing a new candidate for the etiology of muscular dystrophy.

  6. Cavin4b/Murcb Is Required for Skeletal Muscle Development and Function in Zebrafish.

    Directory of Open Access Journals (Sweden)

    Michael P Housley

    2016-06-01

    Full Text Available Skeletal muscles provide metazoans with the ability to feed, reproduce and avoid predators. In humans, a heterogeneous group of genetic diseases, termed muscular dystrophies (MD, lead to skeletal muscle dysfunction. Mutations in the gene encoding Caveolin-3, a principal component of the membrane micro-domains known as caveolae, cause defects in muscle maintenance and function; however it remains unclear how caveolae dysfunction underlies MD pathology. The Cavin family of caveolar proteins can form membrane remodeling oligomers and thus may also impact skeletal muscle function. Changes in the distribution and function of Cavin4/Murc, which is predominantly expressed in striated muscles, have been reported to alter caveolae structure through interaction with Caveolin-3. Here, we report the generation and phenotypic analysis of murcb mutant zebrafish, which display impaired swimming capacity, skeletal muscle fibrosis and T-tubule abnormalities during development. To understand the mechanistic importance of Murc loss of function, we assessed Caveolin-1 and 3 localization and found it to be abnormal. We further identified an in vivo function for Murc in Erk signaling. These data link Murc with developmental defects in T-tubule formation and progressive muscle dysfunction, thereby providing a new candidate for the etiology of muscular dystrophy.

  7. Expression and functional characterization of Smyd1a in myofibril organization of skeletal muscles.

    Science.gov (United States)

    Gao, Jie; Li, Junling; Li, Bao-Jun; Yagil, Ezra; Zhang, Jianshe; Du, Shao Jun

    2014-01-01

    Smyd1, the founding member of the Smyd family including Smyd-1, 2, 3, 4 and 5, is a SET and MYND domain containing protein that plays a key role in myofibril assembly in skeletal and cardiac muscles. Bioinformatic analysis revealed that zebrafish genome contains two highly related smyd1 genes, smyd1a and smyd1b. Although Smyd1b function is well characterized in skeletal and cardiac muscles, the function of Smyd1a is, however, unknown. To investigate the function of Smyd1a in muscle development, we isolated smyd1a from zebrafish, and characterized its expression and function during muscle development via gene knockdown and transgenic expression approaches. The results showed that smyd1a was strongly expressed in skeletal muscles of zebrafish embryos. Functional analysis revealed that knockdown of smyd1a alone had no significant effect on myofibril assembly in zebrafish skeletal muscles. However, knockdown of smyd1a and smyd1b together resulted in a complete disruption of myofibril organization in skeletal muscles, a phenotype stronger than knockdown of smyd1a or smyd1b alone. Moreover, ectopic expression of zebrafish smyd1a or mouse Smyd1 transgene could rescue the myofibril defects from the smyd1b knockdown in zebrafish embryos. Collectively, these data indicate that Smyd1a and Smyd1b share similar biological activity in myofibril assembly in zebrafish embryos. However, Smyd1b appears to play a major role in this process.

  8. Vascular and Skeletal Muscle Function in Gulf War Veterans Illness

    Science.gov (United States)

    2017-07-01

    DNA, RNA, and protein from muscle tissue samples. Prepare cDNA from RNA samples. 4-28 Pending Complete qPCR and Western Blot to assess genes and...Lab from cDNA samples 24-30 Pending Interpret results and identify candidate genes related to Gulf War Illness 24-30 Pending Milestone: Complete

  9. Functional and morphological variety in trunk muscles of Urodela.

    Science.gov (United States)

    Omura, Ayano; Anzai, Wataru; Endo, Hideki

    2014-03-01

    Trunk musculature in Urodela species varies by habitat. In this study, trunk musculature was examined in five species of adult salamanders representing three different habitats: aquatic species, Amphiuma tridactylum and Necturus maculosus; semi-aquatic species, Cynops pyrrhogaster; terrestrial species, Hynobius nigrescens and Ambystoma tigrinum. More terrestrial species have heavier dorsal and ventral trunk muscles than more aquatic forms. By contrast, the lateral hypaxial musculature was stronger in more aquatic species. The number of layers of lateral hypaxial musculature varied among Urodela species and did not clearly correlate with their habitats. The M. rectus abdominis was separated from the lateral hypaxial musculature in both terrestrial and semi-aquatic species. In aquatic species, M. rectus abdominis was not separated from lateral hypaxial musculature. Lateral hypaxial musculature differed in thickness among species and was relatively thinner in terrestrial species. In more terrestrial species, dorsal muscles may be used for stabilization and ventral flexing against gravity. Ventral muscle may be used in preventing dorsally concave curvature of the trunk by dorsal muscles and by weight. The lengthy trunk supported by limbs needs muscular forces along the ventral contour line in more terrestrial species. And, the locomotion on well-developed limbs seems to lead to a decrease of the lateral hypaxial musculature.

  10. Thigh muscle volume predicted by anthropometric measurements and correlated with physical function in the older adults.

    Science.gov (United States)

    Chen, B B; Shih, T T F; Hsu, C Y; Yu, C W; Wei, S Y; Chen, C Y; Wu, C H; Chen, C Y

    2011-06-01

    (1) to correlate thigh muscle volume measured by magnetic resonance image (MRI) with anthropometric measurements and physical function in elderly subjects; (2) to predict MRI-measured thigh muscle volume using anthropometric measurements and physical functional status in elderly subjects. Cross-sectional, nonrandomized study. Outpatient clinic in Taiwan. Sixty-nine elderly subjects (33 men and 36 women) aged 65 and older. The anthropometric data (including body height, body weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRI-measured muscle volume of both thighs was used as the reference standard. The MRI-measured thigh volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time. In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were significant predictors in the linear regression model: Muscle volume (cm3) =4226.3-42.5 × Age (year)-955.7 × gender (male=1, female=2) + 45.9 × body weight(kg) + 60.0 × thigh circumference (cm) (r2 = 0.745, P estimate = 581.6 cm3). The current work provides evidence of a strong relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction equation model using anthropometric measurements. This model is a simple and noninvasive method for everyday clinical practice and follow-up.

  11. Mitochondrial function in human skeletal muscle following high-altitude exposure

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Boushel, Robert; Wright-Paradis, Cynthia

    2013-01-01

    Studies regarding mitochondrial modifications in human skeletal muscle following acclimatization to high altitude are conflicting, and these inconsistencies may be due to the prevalence of representing mitochondrial function through static and isolated measurements of specific mitochondrial...... characteristics. The aim of this study, therefore, was to investigate mitochondrial function in response to high-altitude acclimatization through measurements of respiratory control in the vastus lateralis muscle. Skeletal muscle biopsies were obtained from 10 lowland natives prior to and again after a total of 9......-11 days of exposure to 4559 m. High-resolution respirometry was performed on the muscle samples to compare respiratory chain function and respiratory capacities. Respirometric analysis revealed that mitochondrial function was largely unaffected, because high-altitude exposure did not affect the capacity...

  12. The infiltration of the AC joint performed by one specialist: Ultrasound versus palpation a prospective randomized pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Sabeti-Aschraf, M., E-mail: manuel.sabeti-aschraf@meduniwien.ac.a [Vienna Medical School, Department for Orthopaedics and Orthopaedic Surgery, AKH-Wien, Waehringer Guertel18-20, 1090 Vienna (Austria); Ochsner, A. [Vienna Medical School, Department for Orthopaedics and Orthopaedic Surgery, AKH-Wien, Waehringer Guertel18-20, 1090 Vienna (Austria); Schueller-Weidekamm, C. [Vienna Medical School, Department for Radiology, AKH-Wien, Waehringer Guertel 18-20, 1090 Vienna (Austria); Schmidt, M. [Vienna Medical School, Department for Orthopaedics and Orthopaedic Surgery, AKH-Wien, Waehringer Guertel18-20, 1090 Vienna (Austria); Funovics, Ph.T. [Vienna Medical School, Department for Radiology, AKH-Wien, Waehringer Guertel 18-20, 1090 Vienna (Austria); Skrbensky, G. von [Vienna Medical School, Department for Orthopaedics and Orthopaedic Surgery, AKH-Wien, Waehringer Guertel18-20, 1090 Vienna (Austria); Goll, A. [Vienna Medical School, Core Unit for Medical Statistics and Wien, Waehringer Guertel18-20, 1090 Vienna (Austria); Schatz, K.D. [Vienna Medical School, Department for Orthopaedics and Orthopaedic Surgery, AKH-Wien, Waehringer Guertel18-20, 1090 Vienna (Austria)

    2010-07-15

    Introduction: The acromio-clavicular (AC) joint is very susceptible to degenerative processes that result in pain and functional impairment. One common modality of treatment has been local infiltration of the joint space. Although this procedure has produced notable positive results, needle misplacement occurs frequently. The aim of this investigation is to evaluate the effects of an intra articular infiltration by comparing precise needle placement into the joint space using high-resolution-ultrasound with the conventional palpation technique. Methods: This prospective and randomized pilot study analysed 20 patients who were assigned either to the 'ultrasound' or the 'palpation' group. Clinical examinations were performed before treatment and at 1 h, 1 week and 3 weeks after a single infiltration of local anaesthetic and corticoid carried out by one specialist. Results: In both groups significant improvement in pain and function was obtained up to one-week post injection. Function remained significantly improved until the last follow-up and did not differ between the two groups. The agent was administered in all patients into the joint space in the ultrasound group. Conclusion: Ultrasound guided infiltration of the AC joint is an easily achieved procedure without any complications. However, clinical follow-up did not differ between free-hand and ultrasound-guided AC joint space infiltration.

  13. The infiltration of the AC joint performed by one specialist: Ultrasound versus palpation a prospective randomized pilot study

    International Nuclear Information System (INIS)

    Sabeti-Aschraf, M.; Ochsner, A.; Schueller-Weidekamm, C.; Schmidt, M.; Funovics, Ph.T.; Skrbensky, G. von; Goll, A.; Schatz, K.D.

    2010-01-01

    Introduction: The acromio-clavicular (AC) joint is very susceptible to degenerative processes that result in pain and functional impairment. One common modality of treatment has been local infiltration of the joint space. Although this procedure has produced notable positive results, needle misplacement occurs frequently. The aim of this investigation is to evaluate the effects of an intra articular infiltration by comparing precise needle placement into the joint space using high-resolution-ultrasound with the conventional palpation technique. Methods: This prospective and randomized pilot study analysed 20 patients who were assigned either to the 'ultrasound' or the 'palpation' group. Clinical examinations were performed before treatment and at 1 h, 1 week and 3 weeks after a single infiltration of local anaesthetic and corticoid carried out by one specialist. Results: In both groups significant improvement in pain and function was obtained up to one-week post injection. Function remained significantly improved until the last follow-up and did not differ between the two groups. The agent was administered in all patients into the joint space in the ultrasound group. Conclusion: Ultrasound guided infiltration of the AC joint is an easily achieved procedure without any complications. However, clinical follow-up did not differ between free-hand and ultrasound-guided AC joint space infiltration.

  14. Impaired physical function, loss of muscle mass and assessment of biomechanical properties in critical ill patients

    DEFF Research Database (Denmark)

    Poulsen, Jesper Brøndum

    2012-01-01

    Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment. A plaus......Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment....... A plausible contributor to the accentuated catabolic drive in ICU patients is a synergistic response to inflammation and inactivity leading to loss of muscle mass. As these entities are predominantly present in the early phase of ICU stay, interventions employed during this time frame may exhibit the greatest...... potential to counteract loss of muscle mass. Despite the obvious clinical significance of muscle atrophy for the functional impairment observed in ICU survivors, no preventive therapies have been identified as yet. The overall aim of the present dissertation is to characterize aspects of physical function...

  15. The effect of the inspiratory muscle training on functional ability in stroke patients.

    Science.gov (United States)

    Jung, Nam-Jin; Na, Sang-Su; Kim, Seung-Kyu; Hwangbo, Gak

    2017-11-01

    [Purpose] This study was to find out an inspiratory muscle training (IMT) program therapeutic effects on stroke patients' functional ability. [Subjects and Methods] Twenty stroke patients were assigned to one of two groups: inspiratory muscle training (n=10), and control (n=10), randomization. The inspiratory muscle training participants undertook an exercise program for 30 minute per times, 5 times a week for 6 weeks. The investigator measured the patients' trunk impairment scale (TIS) and 6 minute walking test (6MW) for functional ability before and after IMT. [Results] The TIS appeared some significant differences in both groups before and after the training. The 6MW test showed some significant differences in the inspiratory muscle training group, but didn't show any significant difference in the control group. And the differences in both groups after depending the inspiratory muscle training were significantly found in the tests of TIS and 6MW test [Conclusion] The results showed that the inspiratory muscle training in stroke patients are correlated with the trunk stability and locomotion ability, suggesting that physical therapist must take into consideration the inspiratory muscle training, as well as functional training to improve physical function in stroke patients.

  16. Traditional versus functional strength training: Effects on muscle strength and power in the elderly

    OpenAIRE

    Seiler, Hilde Lohne; Torstveit, Monica Klungland; Anderssen, Sigmund A.

    2013-01-01

    Published versiom of an article in the journal:Journal of Aging and Physical Activity. Also available from Human Kinetics: http://http://journals.humankinetics.com/japa-back-issues/japa-volume-21-issue-1-january/traditional-versus-functional-strength-training-effects-on-muscle-strength-and-power-in-the-elderly The aim was to determine whether strength training with machines vs. functional strength training at 80% of one-repetition maximum improves muscle strength and power among the elderl...

  17. Joint proprioception, muscle strength, and functional ability in patients with osteoarthritis of the knee.

    Science.gov (United States)

    van der Esch, M; Steultjens, M; Harlaar, J; Knol, D; Lems, W; Dekker, J

    2007-06-15

    To test the hypotheses that poor knee joint proprioception is related to limitations in functional ability, and poor proprioception aggravates the impact of muscle weakness on limitations in functional ability in osteoarthritis (OA) of the knee. Sixty-three patients with symptomatic OA of the knee were tested. Proprioceptive acuity was assessed by establishing the joint motion detection threshold (JMDT) in the anteroposterior direction. Muscle strength was measured using a computer-driven isokinetic dynamometer. Functional ability was assessed by the 100-meter walking test, the Get Up and Go (GUG) test, and the Western Ontario and McMaster Universities Osteoarthritis Index physical function (WOMAC-PF) questionnaire. Correlation analyses were performed to assess the relationship between proprioception, muscle strength, and functional ability. Regression analyses were performed to assess the impact of proprioception on the relationship between muscle strength and functional ability. Poor proprioception (high JMDT) was related to more limitation in functional ability (walking time r = 0.30, P < 0.05; GUG time r = 0.30, P < 0.05; WOMAC-PF r = 0.26, P <0.05). In regression analyses, the interaction between proprioception and muscle strength was significantly related to functional ability (walking time, P < 0.001 and GUG time, P < 0.001) but not to WOMAC-PF score (P = 0.625). In patients with poor proprioception, reduction of muscle strength was associated with more severe deterioration of functional ability than in patients with accurate proprioception. Patients with poor proprioception show more limitation in functional ability, but this relationship is rather weak. In patients with poor proprioception, muscle weakness has a stronger impact on limitations in functional ability than in patients with accurate proprioception.

  18. Impact of Functional Appliances on Muscle Activity: A Surface Electromyography Study in Children

    Science.gov (United States)

    Woźniak, Krzysztof; Piątkowska, Dagmara; Szyszka-Sommerfeld, Liliana; Buczkowska-Radlińska, Jadwiga

    2015-01-01

    Background Electromyography (EMG) is the most objective tool for assessing changes in the electrical activity of the masticatory muscles. The purpose of the study was to evaluate the tone of the masseter and anterior temporalis muscles in growing children before and after 6 months of treatment with functional removable orthodontic appliances. Material/Methods The sample conisted of 51 patients with a mean age 10.7 years with Class II malocclusion. EMG recordings were performed by using a DAB-Bluetooth instrument (Zebris Medical GmbH, Germany). Recordings were performed in mandibular rest position, during maximum voluntary contraction (MVC), and during maximum effort. Results The results of the study indicated that the electrical activity of the muscles in each of the clinical situations was the same in the group of girls and boys. The factor that determined the activity of the muscles was their type. In mandibular rest position and in MVC, the activity of the temporalis muscles was significantly higher that that of the masseter muscels. The maximum effort test indicated a higher fatigue in masseter than in temporalis muscles. Conclusions Surface electromyography is a useful tool for monitoring muscle activity. A 6-month period of functional therapy resulted in changes in the activity of the masticatory muscles. PMID:25600247

  19. Association between selenium plasma levels and muscle function in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Milena B Stockler-Pinto

    2012-06-01

    Full Text Available Selenium (Se is a well-known antioxidant with a critical role in the proper functioning of nervous and muscle functions. In the last decade, many authors have suggested that Se may be a potent protective agent for neurons and myocytes through selenoprotein expression in the brain, as well as in skeletal and cardiac muscles. Low Se status has been associated with reduced coordination, motor speed and muscle strength. Reduced muscle function is common in hemodialysis (HD patients; however, no study evaluated the association between muscle function and Se levels in HD patients. The objective of this study was to correlate muscle function with Se plasma levels in HD patients. Twenty HD patients (12 men, 54.5±15.2 yr; 81.7±52.8 months on HD from RenalCor Clinic at Rio de Janeiro, Brazil were studied. Blood samples were collected during fasting, before a regular HD session. The Se plasma levels were determined by atomic absorption spectrophotometry with hydride generation (Hitachi, Z-500 and handgrip strength (HGS was measured three times with a mechanical dynamometer (Jamar after HD sessions in the non-fistula side and the highest value was used for analysis. HGS values less than the 10th percentile of an age-, gender- and regional specific reference were considered as muscle function loss. Plasma Se levels (31.9±14.8 μg/L were below the normal range (60-120 μg/L and all patients were Se deficient. HGS values were significantly greater in males (31.0±11.5 kg vs 14.0±6.8 kg for females (p=0.001 and the muscle function loss was observed in 50% of patients and, those with muscle function loss presented low Se levels (26.5±12.1 μg/L when compared to patients with preserved muscle function (39.12±14.5 μg/L (p=0.05. These data suggest that Se can have an important role on muscle function in HD patients. However, more research is needed to better understand this possible relationship in CKD patients.

  20. Synaptic and functional linkages between spinal premotor interneurons and hand-muscle activity during precision grip

    Directory of Open Access Journals (Sweden)

    Tomohiko eTakei

    2013-04-01

    Full Text Available Grasping is a highly complex movement that requires the coordination of a number of hand joints and muscles. Previous studies showed that spinal premotor interneurons (PreM-INs in the primate cervical spinal cord have divergent synaptic effects on hand motoneurons and that they might contribute to hand-muscle synergies. However, the extent to which these PreM-IN synaptic connections functionally contribute to modulating hand-muscle activity is not clear. In this paper, we explored the contribution of spinal PreM-INs to hand-muscle activation by quantifying the synaptic linkage (SL and functional linkage (FL of the PreM-INs with hand-muscle activities. The activity of 23 PreM-INs was recorded from the cervical spinal cord (C6–T1, with EMG signals measured simultaneously from hand and arm muscles in two macaque monkeys performing a precision grip task. Spike-triggered averages (STAs of rectified EMGs were compiled for 456 neuron–muscle pairs; 63 pairs showed significant post-spike effects (i.e., SL. Conversely, 231 of 456 pairs showed significant cross-correlations between the IN firing rate and rectified EMG (i.e., FL. Importantly, a greater proportion of the neuron–muscle pairs with SL showed FL (43/63 pairs, 68% compared with the pairs without SL (203/393, 52%, and the presence of SL was significantly associated with that of FL. However, a significant number of pairs had SL without FL (SL∩!FL, n = 20 or FL without SL (!SL∩FL, n = 203, and the proportions of these incongruities exceeded the number expected by chance. These results suggested that spinal PreM-INs function to significantly modulate hand-muscle activity during precision grip, but the contribution of other neural structures is also needed to recruit an adequate combination of hand-muscle motoneurons.

  1. Impact of Resistance Training on Skeletal Muscle Mitochondrial Biogenesis, Content, and Function

    Directory of Open Access Journals (Sweden)

    Thomas Groennebaek

    2017-09-01

    Full Text Available Skeletal muscle metabolic and contractile properties are reliant on muscle mitochondrial and myofibrillar protein turnover. The turnover of these specific protein pools is compromised during disease, aging, and inactivity. Oppositely, exercise can accentuate muscle protein turnover, thereby counteracting decay in muscle function. According to a traditional consensus, endurance exercise is required to drive mitochondrial adaptations, while resistance exercise is required to drive myofibrillar adaptations. However, concurrent practice of traditional endurance exercise and resistance exercise regimens to achieve both types of muscle adaptations is time-consuming, motivationally demanding, and contended to entail practice at intensity levels, that may not comply with clinical settings. It is therefore of principle interest to identify effective, yet feasible, exercise strategies that may positively affect both mitochondrial and myofibrillar protein turnover. Recently, reports indicate that traditional high-load resistance exercise can stimulate muscle mitochondrial biogenesis and mitochondrial respiratory function. Moreover, fatiguing low-load resistance exercise has been shown capable of promoting muscle hypertrophy and expectedly entails greater metabolic stress to potentially enhance mitochondrial adaptations. Consequently, fatiguing low-load resistance exercise regimens may possess the ability to stimulate muscle mitochondrial adaptations without compromising muscle myofibrillar accretion. However, the exact ability of resistance exercise to drive mitochondrial adaptations is debatable, not least due to some methodological challenges. The current review therefore aims to address the evidence on the effects of resistance exercise on skeletal muscle mitochondrial biogenesis, content and function. In prolongation, a perspective is taken on the specific potential of low-load resistance exercise on promoting mitochondrial adaptations.

  2. Insulin resistance and mitochondrial function in skeletal muscle

    DEFF Research Database (Denmark)

    Dela, Flemming; Helge, Jørn Wulff

    2013-01-01

    are used in the attempt to resolve the mechanisms of insulin resistance. In this context, a dysfunction of mitochondria in the skeletal muscle has been suggested to play a pivotal role. It has been postulated that a decrease in the content of mitochondria in the skeletal muscle can explain the insulin...... resistance. Complementary to this also specific defects of components in the respiratory chain in the mitochondria have been suggested to play a role in insulin resistance. A key element in these mechanistic suggestions is inability to handle substrate fluxes and subsequently an accumulation of ectopic...... intramyocellular lipids, interfering with insulin signaling. In this review we will present the prevailing view-points and argue for the unlikelihood of this scenario being instrumental in human insulin resistance. This article is part of a Directed Issue entitled: Bioenergetic dysfunction....

  3. Epigenetic regulation of vascular smooth muscle cell function in atherosclerosis.

    Science.gov (United States)

    Findeisen, Hannes M; Kahles, Florian K; Bruemmer, Dennis

    2013-04-01

    Epigenetics involve heritable and acquired changes in gene transcription that occur independently of the DNA sequence. Epigenetic mechanisms constitute a hierarchic upper-level of transcriptional control through complex modifications of chromosomal components and nuclear structures. These modifications include, for example, DNA methylation or post-translational modifications of core histones; they are mediated by various chromatin-modifying enzymes; and ultimately they define the accessibility of a transcriptional complex to its target DNA. Integrating epigenetic mechanisms into the pathophysiologic concept of complex and multifactorial diseases such as atherosclerosis may significantly enhance our understanding of related mechanisms and provide promising therapeutic approaches. Although still in its infancy, intriguing scientific progress has begun to elucidate the role of epigenetic mechanisms in vascular biology, particularly in the control of smooth muscle cell phenotypes. In this review, we will summarize epigenetic pathways in smooth muscle cells, focusing on mechanisms involved in the regulation of vascular remodeling.

  4. Eicosahexanoic Acid (EPA and Docosahexanoic Acid (DHA in Muscle Damage and Function

    Directory of Open Access Journals (Sweden)

    Eisuke Ochi

    2018-04-01

    Full Text Available Nutritional supplementation not only helps in improving and maintaining performance in sports and exercise, but also contributes in reducing exercise fatigue and in recovery from exhaustion. Fish oil contains large amounts of omega-3 fatty acids, eicosapentaenoic acid (EPA; 20:5 n-3 and docosahexaenoic acid (DHA; 22:6 n-3. It is widely known that omega-3 fatty acids are effective for improving cardiac function, depression, cognitive function, and blood as well as lowering blood pressure. In the relationship between omega-3 fatty acids and exercise performance, previous studies have been predicted improved endurance performance, antioxidant and anti-inflammatory responses, and effectivity against delayed-onset muscle soreness. However, the optimal dose, duration, and timing remain unclear. This review focuses on the effects of omega-3 fatty acid on muscle damage and function as evaluated by human and animal studies and summarizes its effects on muscle and nerve damage, and muscle mass and strength.

  5. Effects of Functional Training Program in Core Muscles in Women with Fibromyalgia

    Directory of Open Access Journals (Sweden)

    Iván Darío Pinzón-Ríos

    2015-01-01

    Full Text Available Abstract: Objective: To evaluate the effects of a program of functional muscles core training targeting women with fibromyalgia. Materials and methods: A quasi-experimental type trial was conducted, before and after an intervention, for 20 days, often three days/week, 60 minutes each session. In a single-group of eight women, changes in muscle strength, pain, quality of life related to health and physical activity were evaluated. Results: An increase in repetitions of the test trunk flexion, time on the left and right bridge testing lateral and prone bridge the test were found. All features of pain decreased, and, according to the S-FIQ, a decrease in morning fatigue, stiffness and anxiety was reported. Also Met’s/minute-weeks increased after intervention. Conclusion: These data suggest that functional program core muscle training is effective in increasing muscle strength, pain modulation, functional performance optimization, and increased levels of physical activity in women with fibromyalgia.

  6. Functional alteration of breast muscle fatty acid profile by ...

    African Journals Online (AJOL)

    Breast muscle fatty acid (FA) profile was studied in broiler chickens fed at different levels of n-6:n-3 polyunsaturated fatty acid (PUFA) ratios in 4 treatment groups; very high level of n-6:n-3 ratios (VH), high level of n-6:n-3 ratios (H), low level of n-6:n-3 ratios (L), very low level of n-6:n-3 ratios (VL) and control, respectively.

  7. Muscle Co-activation: Definitions, Mechanisms, and Functions.

    Science.gov (United States)

    Latash, Mark L

    2018-03-28

    The phenomenon of agonist-antagonist muscle co-activation is discussed with respect to its consequences for movement mechanics (such as increasing joint apparent stiffness, facilitating faster movements, and effects on action stability), implication for movement optimization, and involvement of different neurophysiological structures. Effects of co-activation on movement stability are ambiguous and depend on the effector representing a kinematic chain with a fixed origin or free origin. Further, co-activation is discussed within the framework of the equilibrium-point hypothesis and the idea of hierarchical control with spatial referent coordinates. Relations of muscle co-activation to changes in one of the basic commands, the c-command, are discussed and illustrated. A hypothesis is suggested that agonist-antagonist co-activation reflects a deliberate neural control strategy to preserve effector-level control and avoid making it degenerate and facing the necessity to control at the level of signals to individual muscles. This strategy, in particular, allows stabilizing motor actions by co-varied adjustments in spaces of control variables. This hypothesis is able to account for higher levels of co-activation in young healthy persons performing challenging tasks and across various populations with movement impairments.

  8. Two functionally different muscle fibre types in some salps?

    Directory of Open Access Journals (Sweden)

    Q. Bone

    1998-12-01

    Full Text Available This paper describes the structure and operation of the fibres in the locomotor muscle bands of several salp species. In many species, for example Thalia democratica or Pegea confoederata, all the muscle fibres of the locomotor muscle bands are similar in width and structure. In others, for example Salpa fusiformis and S. maxima, although fibre structure is similar, the marginal fibres edging the bands may be some 3-4 times the width of those in the centre of the band. In Ihlea punctata, not only is there a more striking difference in width between the marginal and central fibres of the bands, but also the two differ in structure. The marginal fibres are up to 10 times the width of the central fibres and the two differ in myofibrillar and mitochondrial content. Intracellular recordings from the fibres show that the normally compound spike potentials do not overshoot resting potentials (up to -70 mV, and are decremental. The two types of fibre may be separately activated. It is suggested that in Ihlea punctata, the wide marginal fibres may be involved in slow swimming, the central narrow fibres in `escape´ swimming.

  9. Postoperative Recovery of Mechanical Muscle Function in Hip Replacement Patients

    DEFF Research Database (Denmark)

    Jensen, Carsten; Aagaard, Per; Overgaard, Søren

    2011-01-01

    the posterior-lateral approach. Prior to surgery no training program was initiated but the patients were encouraged to live as usual. Post surgery all patients were allowed fully weight-bearing and they were instructed to follow a conventional home-based rehabilitation, but were otherwise not engaged in any......-test for between group comparisons while ANOVA was used for repeated measures for comparisons over time (α=0.05)   RESULTS The results were calculated as deficits in percentages of the unaffected side (A-NA/NA)*100)) in order to evaluate degree of asymmetry. Our overall side-to-side deficits for peak torque ranged...... from 32.6 to 0.4% and hip flexion deficit being significantly more impacted then the other muscle groups (32.6%).  At baseline all muscle groups showed a significant torque deficit. At 8 weeks post surgery that asymmetry had increased for 4 out of 6 muscle groups. At 26 weeks the hip adduction and hip...

  10. Muscle power is an important measure to detect deficits in muscle function in hip osteoarthritis

    DEFF Research Database (Denmark)

    Bieler, Theresa; Magnusson, Stig Peter; Christensen, Helle Elisabeth

    2017-01-01

    that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with hip osteoarthritis. Implications for Rehabilitation Even in patients with mild symptoms not awaiting hip replacement a generalized muscle weakening......: The symptomatic extremity in patients was significantly (p asymmetry in knee extensor strength (6%, p ... in patients, but had no asymmetry in leg extensor power. CONCLUSIONS: Patients had generalized weakening of the affected lower extremity and numerically the largest asymmetry was evident for leg extensor power. In contrast, healthy peers had no asymmetry in leg extensor power. These results indicate...

  11. Effects of functional exercise training on performance and muscle strength after meniscectomy

    DEFF Research Database (Denmark)

    Ericsson, Y B; Dahlberg, L E; Roos, E M

    2008-01-01

    Muscular deficits and functional limitations have been found years after meniscectomy of the knee. The purpose of this randomized controlled trial was to examine the effect of functional exercise training on functional performance and isokinetic thigh muscle strength in middle-aged patients...... subsequent to meniscectomy for a degenerative tear. Four years after meniscectomy, 45 patients (29 men, 16 women) were randomized to functional exercise training, supervised by a physical therapist, three times weekly for 4 months or to no intervention. The exercise program comprised of postural stability...... training and functional strength and endurance exercises for leg and trunk muscles. Outcomes were three functional performance tests and isokinetic muscle strength. Thirty patients (16 exercisers/14 controls) completed the study. Compared with control patients, the exercise group showed significant...

  12. Prevalence of skeletal muscle mass loss and its association with swallowing function after cardiovascular surgery.

    Science.gov (United States)

    Wakabayashi, Hidetaka; Takahashi, Rimiko; Watanabe, Naoko; Oritsu, Hideyuki; Shimizu, Yoshitaka

    2017-06-01

    The aim of this study was to assess the prevalence of skeletal muscle mass loss and its association with swallowing function in patients with dysphagia after cardiovascular surgery. A retrospective cohort study was performed in 65 consecutive patients with dysphagia after cardiovascular surgery who were prescribed speech therapy. Skeletal muscle index (SMI) was calculated as total psoas muscle area assessed via abdominal computed tomography divided by height squared. Cutoff values were 6.36 cm 2 /m 2 for men and 3.92 cm 2 /m 2 for women. The Food Intake Level Scale (FILS) was used to assess the swallowing function. Univariate and ordered logistic regression analyses were applied to examine the associations between skeletal muscle mass loss and dysphagia. The study included 50 men and 15 women (mean age 73 ± 8 y). The mean SMI was 4.72 ± 1.37 cm 2 /m 2 in men and 3.33 ± 1.42 cm 2 /m 2 in women. Skeletal muscle mass loss was found in 53 (82%) patients. Twelve had tracheostomy cannula. Thirteen were non-oral feeding (FILS levels 1-3), 5 were oral food intake and alternative nutrition (levels 4-6), and 47 were oral food intake alone (levels 7-9) at discharge. The FILS at discharge was significantly lower in patients with skeletal muscle mass loss. Ordered logistic regression analysis of swallowing function showed that skeletal muscle mass loss and tracheostomy cannula were associated independently with the FILS at discharge. The prevalence of skeletal muscle mass loss is very high, and skeletal muscle mass loss is associated with swallowing function. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Enzymatically modified isoquercitrin supplementation intensifies plantaris muscle fiber hypertrophy in functionally overloaded mice.

    Science.gov (United States)

    Kohara, Akiko; Machida, Masanao; Setoguchi, Yuko; Ito, Ryouichi; Sugitani, Masanori; Maruki-Uchida, Hiroko; Inagaki, Hiroyuki; Ito, Tatsuhiko; Omi, Naomi; Takemasa, Tohru

    2017-01-01

    Enzymatically modified isoquercitrin (EMIQ) is produced from rutin using enzymatic hydrolysis followed by treatment with glycosyltransferase in the presence of dextrin to add glucose residues. EMIQ is absorbed in the same way as quercetin, a powerful antioxidant reported to prevent disused muscle atrophy by targeting mitochondria and to have ergogenic effects. The present study investigated the effect of EMIQ on skeletal muscle hypertrophy induced by functional overload. In Study 1, 6-week-old ICR male mice were divided into 4 groups: sham-operated control, sham-operated EMIQ, overload-operated control, and overload-operated EMIQ groups. In Study 2, mice were divided into 3 groups: overload-operated whey control, overload-operated whey/EMIQ (low dose), and overload-operated whey/EMIQ (high dose) groups. The functional overload of the plantaris muscle was induced by ablation of the synergist (gastrocnemius and soleus) muscles. EMIQ and whey protein were administered with food. Three weeks after the operation, the cross-sectional area and minimal fiber diameter of the plantaris muscle fibers were measured. In Study 1, functional overload increased the cross-sectional area and minimal fiber diameter of the plantaris muscle. EMIQ supplementation significantly increased the cross-sectional area and minimal fiber diameter of the plantaris muscle in both the sham-operated and overload-operated groups. In Study 2, EMIQ supplementation combined with whey protein administration significantly increased the cross-sectional area and minimal fiber diameter of the plantaris muscle. EMIQ, even when administered as an addition to whey protein supplementation, significantly intensified the fiber hypertrophy of the plantaris muscle in functionally overloaded mice. EMIQ supplementation also induced fiber hypertrophy of the plantaris in sham-operated mice.

  14. Human lung mast cells modulate the functions of airway smooth muscle cells in asthma.

    Science.gov (United States)

    Alkhouri, H; Hollins, F; Moir, L M; Brightling, C E; Armour, C L; Hughes, J M

    2011-09-01

    Activated mast cell densities are increased on the airway smooth muscle in asthma where they may modulate muscle functions and thus contribute to airway inflammation, remodelling and airflow obstruction. To determine the effects of human lung mast cells on the secretory and proliferative functions of airway smooth muscle cells from donors with and without asthma. Freshly isolated human lung mast cells were stimulated with IgE/anti-IgE. Culture supernatants were collected after 2 and 24 h and the mast cells lysed. The supernatants/lysates were added to serum-deprived, subconfluent airway smooth muscle cells for up to 48 h. Released chemokines and extracellular matrix were measured by ELISA, proliferation was quantified by [(3) H]-thymidine incorporation and cell counting, and intracellular signalling by phospho-arrays. Mast cell 2-h supernatants reduced CCL11 and increased CXCL8 and fibronectin production from both asthmatic and nonasthmatic muscle cells. Leupeptin reversed these effects. Mast cell 24-h supernatants and lysates reduced CCL11 release from both muscle cell types but increased CXCL8 release by nonasthmatic cells. The 24-h supernatants also reduced asthmatic, but not nonasthmatic, muscle cell DNA synthesis and asthmatic cell numbers over 5 days through inhibiting extracellular signal-regulated kinase (ERK) and phosphatidylinositol (PI3)-kinase pathways. However, prostaglandins, thromboxanes, IL-4 and IL-13 were not involved in reducing the proliferation. Mast cell proteases and newly synthesized products differentially modulated the secretory and proliferative functions of airway smooth muscle cells from donors with and without asthma. Thus, mast cells may modulate their own recruitment and airway smooth muscle functions locally in asthma. © 2011 John Wiley & Sons A/S.

  15. Cold water immersion enhances recovery of submaximal muscle function after resistance exercise.

    Science.gov (United States)

    Roberts, Llion A; Nosaka, Kazunori; Coombes, Jeff S; Peake, Jonathan M

    2014-10-15

    We investigated the effect of cold water immersion (CWI) on the recovery of muscle function and physiological responses after high-intensity resistance exercise. Using a randomized, cross-over design, 10 physically active men performed high-intensity resistance exercise followed by one of two recovery interventions: 1) 10 min of CWI at 10°C or 2) 10 min of active recovery (low-intensity cycling). After the recovery interventions, maximal muscle function was assessed after 2 and 4 h by measuring jump height and isometric squat strength. Submaximal muscle function was assessed after 6 h by measuring the average load lifted during 6 sets of 10 squats at 80% of 1 repetition maximum. Intramuscular temperature (1 cm) was also recorded, and venous blood samples were analyzed for markers of metabolism, vasoconstriction, and muscle damage. CWI did not enhance recovery of maximal muscle function. However, during the final three sets of the submaximal muscle function test, participants lifted a greater load (P work during subsequent training sessions, which could enhance long-term training adaptations. Copyright © 2014 the American Physiological Society.

  16. Neck muscle function in violinists/violists with and without neck pain.

    Science.gov (United States)

    Steinmetz, Anke; Claus, Andrew; Hodges, Paul W; Jull, Gwendolen A

    2016-04-01

    Neck pain is associated with changes in neuromuscular control of cervical muscles. Violin and viola playing requires good function of the flexor muscles to stabilize the instrument. This study investigated the flexor muscle behaviour in violin/viola players with and without neck pain using the craniocervical flexion test (CCFT). In total, 12 violin/viola players with neck pain, 21 violin/viola players without neck pain in the preceding 12 weeks and 21 pain-free non-musicians were included. Activity of the sternocleidomastoid muscles (SCM) was measured with surface electromyography (EMG) during the CCFT. Violin/viola players with neck pain displayed greater normalised SCM EMG amplitudes during CCFT than the pain-free musicians and non-musicians (P neck pain in violinists/violists is associated with altered behaviour of the superficial neck flexor muscles consistent with neck pain, despite the specific use of the deep and superficial neck flexors during violin playing.

  17. Effect of generalized joint hypermobility on knee function and muscle activation in children and adults

    DEFF Research Database (Denmark)

    Jensen, Bente Rona; Olesen, Annesofie T.; Pedersen, Mogens Theisen

    2013-01-01

    Introduction: We investigated muscle activation strategy and performance of knee extensor and flexor muscles in children and adults with generalized joint hypermobility (GJH) and compared them with controls. Methods: Muscle activation, torque steadiness, electromechanical delay, and muscle strength...... were evaluated in 39 children and 36 adults during isometric knee extension and flexion. Subjects performed isometric maximum contractions, submaximal contractions at 25% maximum voluntary contraction (MVC), and explosive contractions. Results: Agonist activation was reduced, and coactivation ratio...... was greater in GJH during knee flexion compared with controls. Torque steadiness was impaired in adults with GJH during knee flexion. No effect of GJH was found on muscle strength or electromechanical delay. Correlation analysis revealed an association between GJH severity and function in adults. Conclusions...

  18. A Physiologically Based, Multi-Scale Model of Skeletal Muscle Structure and Function

    Science.gov (United States)

    Röhrle, O.; Davidson, J. B.; Pullan, A. J.

    2012-01-01

    Models of skeletal muscle can be classified as phenomenological or biophysical. Phenomenological models predict the muscle’s response to a specified input based on experimental measurements. Prominent phenomenological models are the Hill-type muscle models, which have been incorporated into rigid-body modeling frameworks, and three-dimensional continuum-mechanical models. Biophysically based models attempt to predict the muscle’s response as emerging from the underlying physiology of the system. In this contribution, the conventional biophysically based modeling methodology is extended to include several structural and functional characteristics of skeletal muscle. The result is a physiologically based, multi-scale skeletal muscle finite element model that is capable of representing detailed, geometrical descriptions of skeletal muscle fibers and their grouping. Together with a well-established model of motor-unit recruitment, the electro-physiological behavior of single muscle fibers within motor units is computed and linked to a continuum-mechanical constitutive law. The bridging between the cellular level and the organ level has been achieved via a multi-scale constitutive law and homogenization. The effect of homogenization has been investigated by varying the number of embedded skeletal muscle fibers and/or motor units and computing the resulting exerted muscle forces while applying the same excitatory input. All simulations were conducted using an anatomically realistic finite element model of the tibialis anterior muscle. Given the fact that the underlying electro-physiological cellular muscle model is capable of modeling metabolic fatigue effects such as potassium accumulation in the T-tubular space and inorganic phosphate build-up, the proposed framework provides a novel simulation-based way to investigate muscle behavior ranging from motor-unit recruitment to force generation and fatigue. PMID:22993509

  19. Functional Segregation within the Muscles of Aquatic Propulsion in the Asiatic Water Monitor (Varanus salvator

    Directory of Open Access Journals (Sweden)

    Bruce Arthur Young

    2016-09-01

    Full Text Available Water monitor lizards (Varanus salvator swim using sinusoidal oscillations generated at the base of their long (50% of total body length tail. In an effort to determine which level of the structural/organizational hierarchy of muscle is associated with functional segregation between the muscles of the tail base, an array of muscle features — myosin heavy chain profiles, enzymatic fiber types, twitch and tetanic force production, rates of fatigue, muscle compliance, and electrical activity patterns — were quantitated. The two examined axial muscles, longissimus and iliocaudalis, were generally similar at the molecular, biochemical, and physiological levels, but differed at the biomechanics level and in their activation pattern. The appendicular muscle examined, caudofemoralis, differed from the axial muscles particularly at the molecular and physiological levels, and it exhibited a unique compliance profile and pattern of electrical activation. There were some apparent contradictions between the different structural/organizational levels examined. These contradictions, coupled with a unique myosin heavy chain profile, lead to the hypothesis that there are previously un-described molecular/biochemical specializations within varanid skeletal muscles.

  20. Targeting deregulated AMPK/mTORC1 pathways improves muscle function in myotonic dystrophy type I.

    Science.gov (United States)

    Brockhoff, Marielle; Rion, Nathalie; Chojnowska, Kathrin; Wiktorowicz, Tatiana; Eickhorst, Christopher; Erne, Beat; Frank, Stephan; Angelini, Corrado; Furling, Denis; Rüegg, Markus A; Sinnreich, Michael; Castets, Perrine

    2017-02-01

    Myotonic dystrophy type I (DM1) is a disabling multisystemic disease that predominantly affects skeletal muscle. It is caused by expanded CTG repeats in the 3'-UTR of the dystrophia myotonica protein kinase (DMPK) gene. RNA hairpins formed by elongated DMPK transcripts sequester RNA-binding proteins, leading to mis-splicing of numerous pre-mRNAs. Here, we have investigated whether DM1-associated muscle pathology is related to deregulation of central metabolic pathways, which may identify potential therapeutic targets for the disease. In a well-characterized mouse model for DM1 (HSALR mice), activation of AMPK signaling in muscle was impaired under starved conditions, while mTORC1 signaling remained active. In parallel, autophagic flux was perturbed in HSALR muscle and in cultured human DM1 myotubes. Pharmacological approaches targeting AMPK/mTORC1 signaling greatly ameliorated muscle function in HSALR mice. AICAR, an AMPK activator, led to a strong reduction of myotonia, which was accompanied by partial correction of misregulated alternative splicing. Rapamycin, an mTORC1 inhibitor, improved muscle relaxation and increased muscle force in HSALR mice without affecting splicing. These findings highlight the involvement of AMPK/mTORC1 deregulation in DM1 muscle pathophysiology and may open potential avenues for the treatment of this disease.

  1. Extrapulmonary features of bronchiectasis: muscle function, exercise capacity, fatigue, and health status

    Directory of Open Access Journals (Sweden)

    Ozalp Ozge

    2012-06-01

    Full Text Available Abstract Background There are limited number of studies investigating extrapulmonary manifestations of bronchiectasis. The purpose of this study was to compare peripheral muscle function, exercise capacity, fatigue, and health status between patients with bronchiectasis and healthy subjects in order to provide documented differences in these characteristics for individuals with and without bronchiectasis. Methods Twenty patients with bronchiectasis (43.5 ± 14.1 years and 20 healthy subjects (43.0 ± 10.9 years participated in the study. Pulmonary function, respiratory muscle strength (maximal expiratory pressure – MIP - and maximal expiratory pressure - MEP, and dyspnea perception using the Modified Medical Research Council Dyspnea Scale (MMRC were determined. A six-minute walk test (6MWT was performed. Quadriceps muscle, shoulder abductor, and hand grip strength (QMS, SAS, and HGS, respectively using a hand held dynamometer and peripheral muscle endurance by a squat test were measured. Fatigue perception and health status were determined using the Fatigue Severity Scale (FSS and the Leicester Cough Questionnaire (LCQ, respectively. Results Number of squats, 6MWT distance, and LCQ scores as well as lung function testing values and respiratory muscle strength were significantly lower and MMRC and FSS scores were significantly higher in patients with bronchiectasis than those of healthy subjects (p p p p p  Conclusions Peripheral muscle endurance, exercise capacity, fatigue and health status were adversely affected by the presence of bronchiectasis. Fatigue was associated with dyspnea and health status. Respiratory muscle strength was related to peripheral muscle strength and health status, but not to fatigue, peripheral muscle endurance or exercise capacity. These findings may provide insight for outcome measures for pulmonary rehabilitation programs for patients with bronchiectasis.

  2. Rbfox-regulated alternative splicing is critical for zebrafish cardiac and skeletal muscle function

    Science.gov (United States)

    Gallagher, Thomas L.; Arribere, Joshua A.; Geurts, Paul A.; Exner, Cameron R. T.; McDonald, Kent L.; Dill, Kariena K.; Marr, Henry L.; Adkar, Shaunak S.; Garnett, Aaron T.; Amacher, Sharon L.; Conboy, John G.

    2012-01-01

    Rbfox RNA binding proteins are implicated as regulators of phylogenetically-conserved alternative splicing events important for muscle function. To investigate the function of rbfox genes, we used morpholino-mediated knockdown of muscle-expressed rbfox1l and rbfox2 in zebrafish embryos. Single and double morphant embryos exhibited changes in splicing of overlapping sets of bioinformatically-predicted rbfox target exons, many of which exhibit a muscle-enriched splicing pattern that is conserved in vertebrates. Thus, conservation of intronic Rbfox binding motifs is a good predictor of Rbfox-regulated alternative splicing. Morphology and development of single morphant embryos was strikingly normal; however, muscle development in double morphants was severely disrupted. Defects in cardiac muscle were marked by reduced heart rate and in skeletal muscle by complete paralysis. The predominance of wavy myofibers and abnormal thick and thin filaments in skeletal muscle revealed that myofibril assembly is defective and disorganized in double morphants. Ultra-structural analysis revealed that although sarcomeres with electron dense M- and Z-bands are present in muscle fibers of rbfox1l/rbox2 morphants, they are substantially reduced in number and alignment. Importantly, splicing changes and morphological defects were rescued by expression of morpholino-resistant rbfox cDNA. Additionally, a target-blocking MO complementary to a single UGCAUG motif adjacent to an rbfox target exon of fxr1 inhibited inclusion in a similar manner to rbfox knockdown, providing evidence that Rbfox regulates the splicing of target exons via direct binding to intronic regulatory motifs. We conclude that Rbfox proteins regulate an alternative splicing program essential for vertebrate heart and skeletal muscle function. PMID:21925157

  3. Rbfox-regulated alternative splicing is critical for zebrafish cardiac and skeletal muscle functions.

    Science.gov (United States)

    Gallagher, Thomas L; Arribere, Joshua A; Geurts, Paul A; Exner, Cameron R T; McDonald, Kent L; Dill, Kariena K; Marr, Henry L; Adkar, Shaunak S; Garnett, Aaron T; Amacher, Sharon L; Conboy, John G

    2011-11-15

    Rbfox RNA binding proteins are implicated as regulators of phylogenetically-conserved alternative splicing events important for muscle function. To investigate the function of rbfox genes, we used morpholino-mediated knockdown of muscle-expressed rbfox1l and rbfox2 in zebrafish embryos. Single and double morphant embryos exhibited changes in splicing of overlapping sets of bioinformatically-predicted rbfox target exons, many of which exhibit a muscle-enriched splicing pattern that is conserved in vertebrates. Thus, conservation of intronic Rbfox binding motifs is a good predictor of Rbfox-regulated alternative splicing. Morphology and development of single morphant embryos were strikingly normal; however, muscle development in double morphants was severely disrupted. Defects in cardiac muscle were marked by reduced heart rate and in skeletal muscle by complete paralysis. The predominance of wavy myofibers and abnormal thick and thin filaments in skeletal muscle revealed that myofibril assembly is defective and disorganized in double morphants. Ultra-structural analysis revealed that although sarcomeres with electron dense M- and Z-bands are present in muscle fibers of rbfox1l/rbox2 morphants, they are substantially reduced in number and alignment. Importantly, splicing changes and morphological defects were rescued by expression of morpholino-resistant rbfox cDNA. Additionally, a target-blocking MO complementary to a single UGCAUG motif adjacent to an rbfox target exon of fxr1 inhibited inclusion in a similar manner to rbfox knockdown, providing evidence that Rbfox regulates the splicing of target exons via direct binding to intronic regulatory motifs. We conclude that Rbfox proteins regulate an alternative splicing program essential for vertebrate heart and skeletal muscle functions. Published by Elsevier Inc.

  4. Effects of inspiratory muscle training on pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation: a randomized controlled trial.

    Science.gov (United States)

    Zeren, Melih; Demir, Rengin; Yigit, Zerrin; Gurses, Hulya N

    2016-12-01

    To investigate the effects of inspiratory muscle training on pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation. Prospective randomized controlled single-blind study. Cardiology department of a university hospital. A total of 38 patients with permanent atrial fibrillation were randomly allocated to either a treatment group (n = 19; age 66.2 years (8.8)) or a control group (n = 19; age 67.1 years (6.4)). The training group received inspiratory muscle training at 30% of maximal inspiratory pressure for 15 minutes twice a day, 7 days a week, for 12 weeks alongside the standard medical treatment. The control group received standard medical treatment only. Spirometry, maximal inspiratory and expiratory pressures and 6-minute walking distance was measured at the beginning and end of the study. There was a significant increase in maximal inspiratory pressure (27.94 cmH 2 O (8.90)), maximal expiratory pressure (24.53 cmH 2 O (10.34)), forced vital capacity (10.29% (8.18) predicted), forced expiratory volume in one second (13.88% (13.42) predicted), forced expiratory flow 25%-75% (14.82% (12.44) predicted), peak expiratory flow (19.82% (15.62) predicted) and 6-minute walking distance (55.53 m (14.13)) in the training group (p  0.05). Inspiratory muscle training can improve pulmonary function, respiratory muscle strength and functional capacity in patients with atrial fibrillation. © The Author(s) 2016.

  5. Functional electrical stimulation of intrinsic laryngeal muscles under varying loads in exercising horses.

    Directory of Open Access Journals (Sweden)

    Jon Cheetham

    Full Text Available Bilateral vocal fold paralysis (BVCP is a life threatening condition and appears to be a good candidate for therapy using functional electrical stimulation (FES. Developing a working FES system has been technically difficult due to the inaccessible location and small size of the sole arytenoid abductor, the posterior cricoarytenoid (PCA muscle. A naturally-occurring disease in horses shares many functional and etiological features with BVCP. In this study, the feasibility of FES for equine vocal fold paralysis was explored by testing arytenoid abduction evoked by electrical stimulation of the PCA muscle. Rheobase and chronaxie were determined for innervated PCA muscle. We then tested the hypothesis that direct muscle stimulation can maintain airway patency during strenuous exercise in horses with induced transient conduction block of the laryngeal motor nerve. Six adult horses were instrumented with a single bipolar intra-muscular electrode in the left PCA muscle. Rheobase and chronaxie were within the normal range for innervated muscle at 0.55±0.38 v and 0.38±0.19 ms respectively. Intramuscular stimulation of the PCA muscle significantly improved arytenoid abduction at all levels of exercise intensity and there was no significant difference between the level of abduction achieved with stimulation and control values under moderate loads. The equine larynx may provide a useful model for the study of bilateral fold paralysis.

  6. Functional deltoid muscle reconstruction following an extensive squamous cell carcinoma resection

    Directory of Open Access Journals (Sweden)

    Tang Weng Jun

    2016-07-01

    Full Text Available Squamous cell carcinoma frequently occurs in an individual with albinism. In this case, the growth of the squamous cell carcinoma was aggressive that it invaded the deltoid muscle. After an oncologic resection, there was a huge defect which required near total resection of the deltoid muscle. Loss of deltoid muscle will lead to the loss of abduction and anterior flexion at the shoulder. This could be debilitating in a person’s normal daily life and activities. Restoration of the shoulder abduction and flexion function with a pedicle bipolar latissimus dorsi flap transfer was chosen in this case due to the versatility and reliability of the flap.

  7. [Progress in isokinetic technology in testing and training for assessment of muscle function].

    Science.gov (United States)

    Huang, Ting-Ting; Fan, Li-Hua; Gao, Dong; Xia, Qing; Zhang, Min

    2013-02-01

    Isokinetic technology in testing and training is the most advanced practical technique in the evaluation of muscle function. This method is a continuous dynamic test in the full range of the joint motion which has strong pertinence at the aspect of assessing muscle strength, and is an objective and quantitative method for reflecting each point's muscle strength in the range of the joint motion. This article reviews the key concepts, brief history of development and influencing factors of isokinetic technology in testing and training, introduces the progress in the field of rehabilitation medicine and sport science, etc., and discusses the future exploration in forensic science.

  8. Venous muscle pump function during pregnancy. Assessment by ambulatory strain-gauge plethysmography

    DEFF Research Database (Denmark)

    Struckmann, J R; Meiland, H; Bagi, P

    1990-01-01

    The venous muscle pump function was quantitatively assessed through pregnancy weeks 16, 30, 38 and 3 months (week 53) following delivery, in 24 pregnant women who completed a normal pregnancy. A statistically significant increase was found in the mean venous reflux (P less than 0.01), which was r...... primarily by mechanical obstruction, or hormonal influence other than that of estradiol, estriol or progesterone. 17% (4.7-37%) of the women with a normal pregnancy developed a pathological venous muscle pump function....... virtually disappeared post partum, corresponding to the muscle pump normalization. No statistical correlation was found between venous muscle pump values and changes in hormone concentrations of estradiol, estriol and progesterone. It is suggested that venous insufficiency development in pregnancy is caused...

  9. Decreased Respiratory Muscle Function Is Associated with Impaired Trunk Balance among Chronic Stroke Patients: A Cross-sectional Study.

    Science.gov (United States)

    Lee, Kyeongbong; Cho, Ji-Eun; Hwang, Dal-Yeon; Lee, WanHee

    2018-06-01

    The abdominal muscles play a role in trunk balance. Abdominal muscle thickness is asymmetrical in stroke survivors, who also have decreased respiratory muscle function. We compared the thickness of the abdominal muscles between the affected and less affected sides in stroke survivors. In addition, the relationship between respiratory muscle function and trunk balance was evaluated. Chronic stroke patients (18 men, 15 women; mean age, 58.94 ± 12.30 years; Mini-Mental Status Examination score ≥ 24) who could sit without assist were enrolled. Abdominal muscle thickness during rest and contraction was measured with ultrasonography, and the thickening ratio was calculated. Respiratory muscle function assessment included maximum respiratory pressure, peak flow, and air volume. Trunk function was evaluated using the Trunk Impairment Scale, and trunk balance was estimated based on the center of pressure velocity and path length within the limit of stability in sitting posture. Abdominal muscles were significantly thinner on the affected side, and the thickening ratio was lower in the affected side (P respiratory muscle function was significantly correlated with higher level of trunk function and balance in stroke patients (P respiratory muscle function has positive correlation with trunk function and balance. We propose that respiratory muscle training should be included as part of trunk balance training in chronic stroke patients.

  10. Ultrasound- versus palpation-guided injection of corticosteroid for plantar fasciitis: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Zonghuan Li

    Full Text Available It is controversial whether ultrasound-guided injection of corticosteroid is superior to palpation-guided injection for plantar fasciitis. This meta-analysis was performed to compare the effectiveness of ultrasound-guided and palpation-guided injection of corticosteroid for the treatment of plantar fasciitis.Databases (MEDLINE, Cochrane library and EMBASE and reference lists were searched from their establishment to August 30, 2013 for randomized controlled trials (RCTs comparing ultrasound-guided with palpation-guided injection for plantar fasciitis. The Cochrane risk of bias (ROB tool was used to assess the methodological quality. Outcome measurements were visual analogue scale (VAS, tenderness threshold (TT, heel tenderness index (HTI, response rate, plantar fascia thickness (PFT, hypoechogenicity and heel pad thickness (HPT. The statistical analysis was performed with software RevMan 5.2 and Stata 12.0. When I2<50%, the fixed-effects model was adopted. Otherwise the randomized-effects model was adopted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE system was used to assess the quality of evidence.Five RCTs with 149 patients were identified and analyzed. Compared with palpation-guided injection, ultrasound-guided injection was superior with regard to VAS, TT, response rate, PFT and hypoechogenicity. However, there was no statistical significance between the two groups for HPT and HTI.Ultrasound-guided injection of corticosteroid tends to be more effective than palpation-guided injection. However, it needs to be confirmed by further research.

  11. Ultrasound- versus Palpation-Guided Injection of Corticosteroid for Plantar Fasciitis: A Meta-Analysis

    Science.gov (United States)

    Yu, Aixi; Qi, Baiwen

    2014-01-01

    Background It is controversial whether ultrasound-guided injection of corticosteroid is superior to palpation-guided injection for plantar fasciitis. This meta-analysis was performed to compare the effectiveness of ultrasound-guided and palpation-guided injection of corticosteroid for the treatment of plantar fasciitis. Methods Databases (MEDLINE, Cochrane library and EMBASE) and reference lists were searched from their establishment to August 30, 2013 for randomized controlled trials (RCTs) comparing ultrasound-guided with palpation-guided injection for plantar fasciitis. The Cochrane risk of bias (ROB) tool was used to assess the methodological quality. Outcome measurements were visual analogue scale (VAS), tenderness threshold (TT), heel tenderness index (HTI), response rate, plantar fascia thickness (PFT), hypoechogenicity and heel pad thickness (HPT). The statistical analysis was performed with software RevMan 5.2 and Stata 12.0. When I2<50%, the fixed-effects model was adopted. Otherwise the randomized-effects model was adopted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the quality of evidence. Results Five RCTs with 149 patients were identified and analyzed. Compared with palpation-guided injection, ultrasound-guided injection was superior with regard to VAS, TT, response rate, PFT and hypoechogenicity. However, there was no statistical significance between the two groups for HPT and HTI. Conclusion Ultrasound-guided injection of corticosteroid tends to be more effective than palpation-guided injection. However, it needs to be confirmed by further research. PMID:24658102

  12. Muscle function-dependent sarcopenia and cut-off values of possible predictors in community-dwelling Turkish elderly: calf circumference, midarm muscle circumference and walking speed.

    Science.gov (United States)

    Akın, S; Mucuk, S; Öztürk, A; Mazıcıoğlu, M; Göçer, Ş; Arguvanlı, S; Şafak, E D

    2015-10-01

    The aim of this study was to determine the prevalence of muscle strength-based sarcopenia and to determine possible predictors. This is a cross-sectional population-based study in the community-dwelling Turkish elderly. Anthropometric measurements, namely body height, weight, triceps skin fold (TSF), mid upper arm circumference (MUAC), waist circumference (WC) and calf circumference (CC), were noted. The midarm muscle circumference (MAMC) was calculated by using MUAC and TSF measurement. Sarcopenia was assessed, adjusted for body mass index (BMI) and gender, according to muscle strength. Physical performance was determined by 4 m walking speed (WS; m/s). The receiver operating curve analysis was performed to determine cut-offs of CC, MAMC and 4 m WS. A total of 879 elderly subjects, 50.1% of whom were female, were recruited. The mean handgrip strength (HGS) and s.d. was 24.2 (8.8) kg [17.9 (4.8) female, 30.6 (7.1) male]. The muscle function-dependent sarcopenia was 63.4% (female 73.5%, male 53.2%). The muscle mass-dependent sarcopenia for CC (sarcopenia. An adequate muscle mass may not mean a reliable muscle function. Muscle function may describe sarcopenia better compared with muscle mass. The CC, MAMC and 4 m WS cut-offs may be used to assess sarcopenia in certain age groups.

  13. Lactate dehydrogenase regulation in aged skeletal muscle: Regulation by anabolic steroids and functional overload.

    Science.gov (United States)

    Washington, Tyrone A; Healey, Julie M; Thompson, Raymond W; Lowe, Larry L; Carson, James A

    2014-09-01

    Aging alters the skeletal muscle response to overload-induced growth. The onset of functional overload is characterized by increased myoblast proliferation and an altered muscle metabolic profile. The onset of functional overload is associated with increased energy demands that are met through the interconversion of lactate and pyruvate via the activity of lactate dehydrogenase (LDH). Testosterone targets many of the processes activated at the onset of functional overload. However, the effect of aging on this metabolic plasticity at the onset of functional overload and how anabolic steroid administration modulates this response is not well understood. The purpose of this study was to determine if aging would alter overload-induced LDH activity and expression at the onset of functional overload and whether anabolic steroid administration would modulate this response. Five-month and 25-month male Fischer 344xF1 BRN were given nandrolone decanoate (ND) or sham injections for 14days and then the plantaris was functionally overloaded (OV) for 3days by synergist ablation. Aging reduced muscle LDH-A & LDH-B activity 70% (pyoung muscle. Our study provides evidence that aging alters aspects of skeletal muscle metabolic plasticity normally induced by overload and anabolic steroid administration. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Effectiveness of water-based Liuzijue exercise on respiratory muscle strength and peripheral skeletal muscle function in patients with COPD

    Directory of Open Access Journals (Sweden)

    Wu W

    2018-05-01

    beneficial effects on COPD patients’ respiratory muscle strength and peripheral skeletal muscle function, and additional benefits may exist in endurance of upper limbs and strength and endurance of lower limbs when compared with land-based Liuzijue exercise. Keywords: COPD, Liuzijue exercise, water-based exercise, respiratory muscle strength, isokinetic muscle strength, quantitative assessment

  15. Volumetric Muscle Loss: Persistent Functional Deficits Beyond Frank Loss of Tissue

    Science.gov (United States)

    2014-09-18

    and fascia covering the tibialis anterior (TA) muscle were bluntly separated from the musculature. The tissue covering all aspects of the middle...testing system.5 Peak TA muscle isometric torque was determined with the ankle at a right angle 0˚ and 20˚ of dorsi- or plantar flexion, assuming a moment...of plantar and dorsiflexion). At all joint angles, VML resulted in a significant functional deficit, although a greater torque deficit was observed

  16. Muscle activity during functional coordination training: implications for strength gain and rehabilitation

    DEFF Research Database (Denmark)

    Jørgensen, Marie Birk; Andersen, Lars Louis; Kirk, Niels

    2010-01-01

    The purpose of this study was to evaluate if different types, body positions, and levels of progression of functional coordination exercises can provide sufficiently high levels of muscle activity to improve strength of the neck, shoulder, and trunk muscles. Nine untrained women were familiarized...... to the maximal EMG activity during maximal voluntary contractions, and a p value 60% of maximal EMG activity). Type of exercise played a significant role...

  17. Musculoskeletal Geometry, Muscle Architecture and Functional Specialisations of the Mouse Hindlimb.

    Directory of Open Access Journals (Sweden)

    James P Charles

    Full Text Available Mice are one of the most commonly used laboratory animals, with an extensive array of disease models in existence, including for many neuromuscular diseases. The hindlimb is of particular interest due to several close muscle analogues/homologues to humans and other species. A detailed anatomical study describing the adult morphology is lacking, however. This study describes in detail the musculoskeletal geometry and skeletal muscle architecture of the mouse hindlimb and pelvis, determining the extent to which the muscles are adapted for their function, as inferred from their architecture. Using I2KI enhanced microCT scanning and digital segmentation, it was possible to identify 39 distinct muscles of the hindlimb and pelvis belonging to nine functional groups. The architecture of each of these muscles was determined through microdissections, revealing strong architectural specialisations between the functional groups. The hip extensors and hip adductors showed significantly stronger adaptations towards high contraction velocities and joint control relative to the distal functional groups, which exhibited larger physiological cross sectional areas and longer tendons, adaptations for high force output and elastic energy savings. These results suggest that a proximo-distal gradient in muscle architecture exists in the mouse hindlimb. Such a gradient has been purported to function in aiding locomotor stability and efficiency. The data presented here will be especially valuable to any research with a focus on the architecture or gross anatomy of the mouse hindlimb and pelvis musculature, but also of use to anyone interested in the functional significance of muscle design in relation to quadrupedal locomotion.

  18. Increasing Muscle Mass Improves Vascular Function in Obese (db/db) Mice

    Science.gov (United States)

    Qiu, Shuiqing; Mintz, James D.; Salet, Christina D.; Han, Weihong; Giannis, Athanassios; Chen, Feng; Yu, Yanfang; Su, Yunchao; Fulton, David J.; Stepp, David W.

    2014-01-01

    Background A sedentary lifestyle is an independent risk factor for cardiovascular disease and exercise has been shown to ameliorate this risk. Inactivity is associated with a loss of muscle mass, which is also reversed with isometric exercise training. The relationship between muscle mass and vascular function is poorly defined. The aims of the current study were to determine whether increasing muscle mass by genetic deletion of myostatin, a negative regulator of muscle growth, can influence vascular function in mesenteric arteries from obese db/db mice. Methods and Results Myostatin expression was elevated in skeletal muscle of obese mice and associated with reduced muscle mass (30% to 50%). Myostatin deletion increased muscle mass in lean (40% to 60%) and obese (80% to 115%) mice through increased muscle fiber size (PMyostatin deletion decreased adipose tissue in lean mice, but not obese mice. Markers of insulin resistance and glucose tolerance were improved in obese myostatin knockout mice. Obese mice demonstrated an impaired endothelial vasodilation, compared to lean mice. This impairment was improved by superoxide dismutase mimic Tempol. Deletion of myostatin improved endothelial vasodilation in mesenteric arteries in obese, but not in lean, mice. This improvement was blunted by nitric oxide (NO) synthase inhibitor l‐NG‐nitroarginine methyl ester (l‐NAME). Prostacyclin (PGI2)‐ and endothelium‐derived hyperpolarizing factor (EDHF)‐mediated vasodilation were preserved in obese mice and unaffected by myostatin deletion. Reactive oxygen species) was elevated in the mesenteric endothelium of obese mice and down‐regulated by deletion of myostatin in obese mice. Impaired vasodilation in obese mice was improved by NADPH oxidase inhibitor (GKT136901). Treatment with sepiapterin, which increases levels of tetrahydrobiopterin, improved vasodilation in obese mice, an improvement blocked by l‐NAME. Conclusions Increasing muscle mass by genetic deletion of

  19. Effects of anabolic hormones on structural, metabolic and functional aspects of skeletal muscle

    Directory of Open Access Journals (Sweden)

    Flávio de Oliveira Pires

    2009-01-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n3p350   This study reviewed information regarding the effects of anabolic hormones on strength gain and muscle hypertrophy, emphasizing the physiological mechanisms that may increase muscle strength. Structural, metabolic and functional aspects were analyzed and special attention was paid to the dose-response relationship. The Pubmed database was searched and studies were selected according to relevance and date of publication (last 15 years. The administration of high testosterone doses (~600 mg/week potentiates the effects of strength training, increasing lean body mass, muscle fiber type IIA and IIB cross-sectional area, and the number of myonuclei. There is no evidence of conversion between MHC isoforms. The interaction between testosterone administration and strength training seems to modify some metabolic pathways, increasing protein synthesis, glycogen and ATP-CP muscle stores and improving fat mobilization. Changes in 17-estradiol concentration or in the ACTH-cortisol and insulin-glucagon ratios seem to be associated with these metabolic alterations. Regarding performance, testosterone administration may improve muscle strength by 5-20% depending on the dose used. On the other hand, the effects of growth hormone on the structural and functional aspects of skeletal muscle are not evident, with this hormone more affecting metabolic aspects. However, strictly controlled human studies are necessary to establish the extent of the effects of anabolic hormones on structural, metabolic and functional aspects.

  20. Effects of anabolic hormones on structural, metabolic and functional aspects of skeletal muscle

    Directory of Open Access Journals (Sweden)

    Flávio de Oliveira Pires

    2009-06-01

    Full Text Available This study reviewed information regarding the effects of anabolic hormones on strength gain and muscle hypertrophy, emphasizing the physiological mechanisms that may increase muscle strength. Structural, metabolic and functional aspects were analyzed and special attention was paid to the dose-response relationship. The Pubmed database was searched and studies were selected according to relevance and date of publication (last 15 years. The administration of high testosterone doses (~600 mg/week potentiates the effects of strength training, increasing lean body mass, muscle fiber type IIA and IIB cross-sectional area, and the number of myonuclei. There is no evidence of conversion between MHC isoforms. The interaction between testosterone administration and strength training seems to modify some metabolic pathways, increasing protein synthesis, glycogen and ATP-CP muscle stores and improving fat mobilization. Changes in 17-estradiol concentration or in the ACTH-cortisol and insulin-glucagon ratios seem to be associated with these metabolic alterations. Regarding performance, testosterone administration may improve muscle strength by 5-20% depending on the dose used. On the other hand, the effects of growth hormone on the structural and functional aspects of skeletal muscle are not evident, with this hormone more affecting metabolic aspects. However, strictly controlled human studies are necessary to establish the extent of the effects of anabolic hormones on structural, metabolic and functional aspects.

  1. Optogenetic probing of nerve and muscle function after facial nerve lesion in the mouse whisker system

    Science.gov (United States)

    Bandi, Akhil; Vajtay, Thomas J.; Upadhyay, Aman; Yiantsos, S. Olga; Lee, Christian R.; Margolis, David J.

    2018-02-01

    Optogenetic modulation of neural circuits has opened new avenues into neuroscience research, allowing the control of cellular activity of genetically specified cell types. Optogenetics is still underdeveloped in the peripheral nervous system, yet there are many applications related to sensorimotor function, pain and nerve injury that would be of great benefit. We recently established a method for non-invasive, transdermal optogenetic stimulation of the facial muscles that control whisker movements in mice (Park et al., 2016, eLife, e14140)1. Here we present results comparing the effects of optogenetic stimulation of whisker movements in mice that express channelrhodopsin-2 (ChR2) selectively in either the facial motor nerve (ChAT-ChR2 mice) or muscle (Emx1-ChR2 or ACTA1-ChR2 mice). We tracked changes in nerve and muscle function before and up to 14 days after nerve transection. Optogenetic 460 nm transdermal stimulation of the distal cut nerve showed that nerve degeneration progresses rapidly over 24 hours. In contrast, the whisker movements evoked by optogenetic muscle stimulation were up-regulated after denervation, including increased maximum protraction amplitude, increased sensitivity to low-intensity stimuli, and more sustained muscle contractions (reduced adaptation). Our results indicate that peripheral optogenetic stimulation is a promising technique for probing the timecourse of functional changes of both nerve and muscle, and holds potential for restoring movement after paralysis induced by nerve damage or motoneuron degeneration.

  2. Functional recovery of denervated skeletal muscle with sensory or mixed nerve protection: a pilot study.

    Directory of Open Access Journals (Sweden)

    Qing Tian Li

    Full Text Available Functional recovery is usually poor following peripheral nerve injury when reinnervation is delayed. Early innervation by sensory nerve has been indicated to prevent atrophy of the denervated muscle. It is hypothesized that early protection with sensory axons is adequate to improve functional recovery of skeletal muscle following prolonged denervation of mixed nerve injury. In this study, four groups of rats received surgical denervation of the tibial nerve. The proximal and distal stumps of the tibial nerve were ligated in all animals except for those in the immediate repair group. The experimental groups underwent denervation with nerve protection of peroneal nerve (mixed protection or sural nerve (sensory protection. The experimental and unprotected groups had a stage II surgery in which the trimmed proximal and distal tibial nerve stumps were sutured together. After 3 months of recovery, electrophysiological, histological and morphometric parameters were assessed. It was detected that the significant muscle atrophy and a good preserved structure of the muscle were observed in the unprotected and protective experimental groups, respectively. Significantly fewer numbers of regenerated myelinated axons were observed in the sensory-protected group. Enhanced recovery in the mixed protection group was indicated by the results of the muscle contraction force tests, regenerated myelinated fiber, and the results of the histological analysis. Our results suggest that early axons protection by mixed nerve may complement sensory axons which are required for promoting functional recovery of the denervated muscle natively innervated by mixed nerve.

  3. Muscle function and body composition profile in adolescents with restrictive anorexia nervosa: does resistance training help?

    Science.gov (United States)

    Fernández-del-Valle, Maria; Larumbe-Zabala, Eneko; Morande-Lavin, Gonzalo; Perez Ruiz, Margarita

    2016-01-01

    The aim of this study was to analyze the effects of short-term resistance training on the body composition profile and muscle function in a group of Anorexia Nervosa restricting type (AN-R) patients. The sample consisted of AN-R female adolescents (12.8 ± 0.6 years) allocated into the control and intervention groups (n = 18 each). Body composition and relative strength were assessed at baseline, after 8 weeks and 4 weeks following the intervention. Body mass index (BMI) increased throughout the study (p = 0.011). Significant skeletal muscle mass (SMM) gains were found in the intervention group (p = 0.045, d = 0.6) that correlated to the change in BMI (r = 0.51, p  0.60) with change in BMI in both the groups. Significant relative strength increases (p Anorexia Nervosa Restricting Type (AN-R) AN-R is a psychiatric disorder that has a major impact on muscle mass content and function. However, little or no attention has been paid to muscle recovery. High intensity resistance training is safe for AN-R after hospitalization and enhances the force generating capacity as well as muscle mass gains. Skeletal muscle mass content and muscular function improvements are partially maintained for a short period of time when the exercise program ceases.

  4. Upper Extremity Muscle Volumes and Functional Strength After Resistance Training in Older Adults

    Science.gov (United States)

    Daly, Melissa; Vidt, Meghan E.; Eggebeen, Joel D.; Simpson, W. Greg; Miller, Michael E.; Marsh, Anthony P.; Saul, Katherine R.

    2014-01-01

    Aging leads to a decline in strength and an associated loss of independence. The authors examined changes in muscle volume, maximum isometric joint moment, functional strength, and 1-repetition maximum (1RM) after resistance training (RT) in the upper extremity of older adults. They evaluated isometric joint moment and muscle volume as predictors of functional strength. Sixteen healthy older adults (average age 75 ± 4.3 yr) were randomized to a 6-wk upper extremity RT program or control group. The RT group increased 1RM significantly (p strength (p = .003), isometric shoulder-adduction moment (p = .041), elbow-flexor volume (p = .017), and shoulder-adductor volume (p = .009). Shoulder-muscle volumes and isometric moments were good predictors of functional strength. The authors conclude that shoulder strength is an important factor for performing functional reaching and pulling tasks and a key target for upper extremity RT interventions. PMID:22952203

  5. Is the relationship between increased knee muscle strength and improved physical function following exercise dependent on baseline physical function status?

    Science.gov (United States)

    Hall, Michelle; Hinman, Rana S; van der Esch, Martin; van der Leeden, Marike; Kasza, Jessica; Wrigley, Tim V; Metcalf, Ben R; Dobson, Fiona; Bennell, Kim L

    2017-12-08

    Clinical guidelines recommend knee muscle strengthening exercises to improve physical function. However, the amount of knee muscle strength increase needed for clinically relevant improvements in physical function is unclear. Understanding how much increase in knee muscle strength is associated with improved physical function could assist clinicians in providing appropriate strength gain targets for their patients in order to optimise outcomes from exercise. The aim of this study was to investigate whether an increase in knee muscle strength is associated with improved self-reported physical function following exercise; and whether the relationship differs according to physical function status at baseline. Data from 100 participants with medial knee osteoarthritis enrolled in a 12-week randomised controlled trial comparing neuromuscular exercise to quadriceps strengthening exercise were pooled. Participants were categorised as having mild, moderate or severe physical dysfunction at baseline using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Associations between 12-week changes in physical function (dependent variable) and peak isometric knee extensor and flexor strength (independent variables) were evaluated with and without accounting for baseline physical function status and covariates using linear regression models. In covariate-adjusted models without accounting for baseline physical function, every 1-unit (Nm/kg) increase in knee extensor strength was associated with physical function improvement of 17 WOMAC units (95% confidence interval (CI) -29 to -5). When accounting for baseline severity of physical function, every 1-unit increase in knee extensor strength was associated with physical function improvement of 24 WOMAC units (95% CI -42 to -7) in participants with severe physical dysfunction. There were no associations between change in strength and change in physical function in participants with mild or moderate physical

  6. Impaired exercise performance and skeletal muscle mitochondrial function in rats with secondary carnitine deficiency

    Directory of Open Access Journals (Sweden)

    Jamal BOUITBIR

    2016-08-01

    Full Text Available Purpose: The effects of carnitine depletion upon exercise performance and skeletal muscle mitochondrial function remain largely unexplored. We therefore investigated the effect of N-trimethyl-hydrazine-3-propionate (THP, a carnitine analogue inhibiting carnitine biosynthesis and renal carnitine reabsorption, on physical performance and skeletal muscle mitochondrial function in rats.Methods: Male Sprague Dawley rats were treated daily with water (control rats; n=12 or with 20 mg/100 g body weight THP (n=12 via oral gavage for 3 weeks. Following treatment, half of the animals of each group performed an exercise test until exhaustion.Results: Distance covered and exercise performance were lower in THP-treated compared to control rats. In the oxidative soleus muscle, carnitine depletion caused atrophy (-24% and impaired function of complex II and IV of the mitochondrial electron transport chain. The free radical leak (ROS production relative to oxygen consumption was increased and the cellular glutathione pool decreased. Moreover, mRNA expression of markers of mitochondrial biogenesis and mitochondrial DNA were decreased in THP-treated compared to control rats. In comparison, in the glycolytic gastrocnemius muscle, carnitine depletion was associated with impaired function of complex IV and increased free radical leak, whilst muscle weight and cellular glutathione pool were maintained. Markers of mitochondrial proliferation and mitochondrial DNA were unaffected.Conclusions: Carnitine deficiency is associated with impaired exercise capacity in rats treated with THP. THP-induced carnitine deficiency is associated with impaired function of the electron transport chain in oxidative and glycolytic muscle as well as with atrophy and decreased mitochondrial DNA in oxidative muscle.

  7. Expression and functional characterization of Smyd1a in myofibril organization of skeletal muscles.

    Directory of Open Access Journals (Sweden)

    Jie Gao

    Full Text Available BACKGROUND: Smyd1, the founding member of the Smyd family including Smyd-1, 2, 3, 4 and 5, is a SET and MYND domain containing protein that plays a key role in myofibril assembly in skeletal and cardiac muscles. Bioinformatic analysis revealed that zebrafish genome contains two highly related smyd1 genes, smyd1a and smyd1b. Although Smyd1b function is well characterized in skeletal and cardiac muscles, the function of Smyd1a is, however, unknown. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the function of Smyd1a in muscle development, we isolated smyd1a from zebrafish, and characterized its expression and function during muscle development via gene knockdown and transgenic expression approaches. The results showed that smyd1a was strongly expressed in skeletal muscles of zebrafish embryos. Functional analysis revealed that knockdown of smyd1a alone had no significant effect on myofibril assembly in zebrafish skeletal muscles. However, knockdown of smyd1a and smyd1b together resulted in a complete disruption of myofibril organization in skeletal muscles, a phenotype stronger than knockdown of smyd1a or smyd1b alone. Moreover, ectopic expression of zebrafish smyd1a or mouse Smyd1 transgene could rescue the myofibril defects from the smyd1b knockdown in zebrafish embryos. CONCLUSION/SIGNIFICANCE: Collectively, these data indicate that Smyd1a and Smyd1b share similar biological activity in myofibril assembly in zebrafish embryos. However, Smyd1b appears to play a major role in this process.

  8. Adjustment of muscle function to flight in bats; Komori no kinkino no hiko eno tekio

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, M. [Institute of the Space and Astronautical Science,Tokyo (Japan); Choi, I.H.

    1999-12-05

    This paper outlines the muscle of bats that generates a motive force for flight. The weight of the muscle is less compared with that of birds. The energy required for flight is twice as much as that for running. Conversely, in view of metabolic cost (transporting cost) for moving a unit mass for a unit distance, the transporting cost of bats for flying is one fifth. The acquisition of this flight ability through evolution can be inferred from the fossils of reptiles. Bats, having a stream-lined body shape and a small body mass, are capable of efficient flight. A fast durable flight is possible by having the pectoral muscle constituted of speed muscles of oxidation/glycolysis muscle fiber, a well-developed oxygen transporting system, the arrangement around the capillary of mitochondria and fat grains that are cell organs for producing energy, and a high-density contact between the capillary and the muscle fiber. The muscle functions at low body temperature and imparts adaptability to hibernation with the body temperature lowered. The flight is controlled by the cycle and synchronized with this biological clock, optical cycle and change in temperature. (NEDO)

  9. The functional significance of hamstrings composition: is it really a "fast" muscle group?

    Science.gov (United States)

    Evangelidis, Pavlos E; Massey, Garry J; Ferguson, Richard A; Wheeler, Patrick C; Pain, Matthew T G; Folland, Jonathan P

    2017-11-01

    Hamstrings muscle fiber composition may be predominantly fast-twitch and could explain the high incidence of hamstrings strain injuries. However, hamstrings muscle composition in vivo, and its influence on knee flexor muscle function, remains unknown. We investigated biceps femoris long head (BFlh) myosin heavy chain (MHC) composition from biopsy samples, and the association of hamstrings composition and hamstrings muscle volume (using MRI) with knee flexor maximal and explosive strength. Thirty-one young men performed maximal (concentric, eccentric, isometric) and explosive (isometric) contractions. BFlh exhibited a balanced MHC distribution [mean ± SD (min-max); 47.1 ± 9.1% (32.6-71.0%) MHC-I, 35.5 ± 8.5% (21.5-60.0%) MHC-IIA, 17.4 ± 9.1% (0.0-30.9%) MHC-IIX]. Muscle volume was correlated with knee flexor maximal strength at all velocities and contraction modes (r = 0.62-0.76, P hamstrings strain injury. Hamstrings muscle volume explained 38-58% of the inter-individual differences in knee flexor maximum strength at a range of velocities and contraction modes, while BFlh muscle composition was not associated with maximal or explosive strength. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. The effect of neuromuscular electrical stimulation on muscle strength, functional capacity and body composition in haemodialysis patients

    Directory of Open Access Journals (Sweden)

    Vicent Esteve

    2017-01-01

    Conclusions: (1 NMES improved muscle strength, functional capacity and quadriceps muscle composition in our patients. (2 Based on the results obtained, NMES could be a new therapeutic alternative to prevent muscle atrophy and progressive physical deterioration. (3 However, future studies are necessary to establish the potential beneficial effects of NMES in HD patients.

  11. In vivo generation of a mature and functional artificial skeletal muscle.

    Science.gov (United States)

    Fuoco, Claudia; Rizzi, Roberto; Biondo, Antonella; Longa, Emanuela; Mascaro, Anna; Shapira-Schweitzer, Keren; Kossovar, Olga; Benedetti, Sara; Salvatori, Maria L; Santoleri, Sabrina; Testa, Stefano; Bernardini, Sergio; Bottinelli, Roberto; Bearzi, Claudia; Cannata, Stefano M; Seliktar, Dror; Cossu, Giulio; Gargioli, Cesare

    2015-04-01

    Extensive loss of skeletal muscle tissue results in mutilations and severe loss of function. In vitro-generated artificial muscles undergo necrosis when transplanted in vivo before host angiogenesis may provide oxygen for fibre survival. Here, we report a novel strategy based upon the use of mouse or human mesoangioblasts encapsulated inside PEG-fibrinogen hydrogel. Once engineered to express placental-derived growth factor, mesoangioblasts attract host vessels and nerves, contributing to in vivo survival and maturation of newly formed myofibres. When the graft was implanted underneath the skin on the surface of the tibialis anterior, mature and aligned myofibres formed within several weeks as a complete and functional extra muscle. Moreover, replacing the ablated tibialis anterior with PEG-fibrinogen-embedded mesoangioblasts also resulted in an artificial muscle very similar to a normal tibialis anterior. This strategy opens the possibility for patient-specific muscle creation for a large number of pathological conditions involving muscle tissue wasting. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

  12. Acute effects of inspiratory muscle warm-up on pulmonary function in healthy subjects.

    Science.gov (United States)

    Özdal, Mustafa

    2016-06-15

    The acute effects of inspiratory muscle warm-up on pulmonary functions were examined in 26 healthy male subjects using the pulmonary function test (PFT) in three different trials. The control trial (CON) did not involve inspiratory muscle warm-up, while the placebo (IMWp) and experimental (IMW) trials involved inspiratory muscle warm-up. There were no significant changes between the IMWp and CON trials (p>0.05). All the PFT measurements, including slow vital capacity, inspiratory vital capacity, forced vital capacity, forced expiratory volume in one second, maximal voluntary ventilation, and maximal inspiratory pressure were significantly increased by 3.55%, 12.52%, 5.00%, 2.75%, 2.66%, and 7.03% respectively, in the subjects in the IMW trial than those in the CON trial (pcooperation of the upper thorax, neck, and respiratory muscles, and increased level of reactive O2 species in muscle tissue, and potentially improvement of muscle O2 delivery-to-utilization. However, further investigation is required to determine the precise mechanisms responsible from among these candidates. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Reviewing the technological challenges associated with the development of a laparoscopic palpation device.

    Science.gov (United States)

    Culmer, Peter; Barrie, Jenifer; Hewson, Rob; Levesley, Martin; Mon-Williams, Mark; Jayne, David; Neville, Anne

    2012-06-01

    Minimally invasive surgery (MIS) has heralded a revolution in surgical practice, with numerous advantages over open surgery. Nevertheless, it prevents the surgeon from directly touching and manipulating tissue and therefore severely restricts the use of valuable techniques such as palpation. Accordingly a key challenge in MIS is to restore haptic feedback to the surgeon. This paper reviews the state-of-the-art in laparoscopic palpation devices (LPDs) with particular focus on device mechanisms, sensors and data analysis. It concludes by examining the challenges that must be overcome to create effective LPD systems that measure and display haptic information to the surgeon for improved intraoperative assessment. Copyright © 2012 John Wiley & Sons, Ltd.

  14. A mixed reality simulator for feline abdominal palpation training in veterinary medicine.

    Science.gov (United States)

    Parkes, Rebecca; Forrest, Neil; Baillie, Sarah

    2009-01-01

    The opportunities for veterinary students to practice feline abdominal palpation are limited as cats have a low tolerance to being examined. Therefore, a mixed reality simulator was developed to complement clinical training. Two PHANToM premium haptic devices were positioned either side of a modified toy cat. Virtual models of the chest and some abdominal contents were superimposed on the physical model. The haptic properties of the virtual models were set by seven veterinarians; values were adjusted while the simulation was being palpated until the representation was satisfactory. Feedback from the veterinarians was encouraging suggesting that the simulator has a potential role in student training.

  15. Exercise induced effects on muscle function and range of motion in patients with hip osteoarthritis

    DEFF Research Database (Denmark)

    Bieler, Theresa; Siersma, Volkert; Magnusson, S Peter

    2018-01-01

    BACKGROUND AND PURPOSE: Patients with hip osteoarthritis have impairments in muscle function (muscle strength and power) and hip range of motion (ROM), and it is commonly believed that effective clinical management of osteoarthritis should address these impairments to reduce pain and disability......-two patients were randomized to either 4 months of physiotherapist-supervised, moderate, progressive, strength training (n = 50), physiotherapist-supervised NW (n = 50), or unsupervised HBE (n = 52). Maximal isometric hip and thigh muscle strength and leg extensor power and active hip ROM were assessed...... at baseline 2, 4, and 12 months. RESULTS: Intention-to-treat-analyses did not show any significant between-group differences for improvements in muscle strength and power or ROM at any time points. Short-term significant (p

  16. Vascular Function and Regulation of Blood Flow in Resting and Contracting Skeletal Muscle

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin

    importance. The present work provides new insight in to vasodilator interactions important for exercise hyperemia and sheds light on mechanisms important for vascular function and regulation of skeletal muscle blood flow in essential hypertension (high blood pressure) and aging and identifies mechanisms......The precise matching of blood flow, oxygen delivery and metabolism is essential as it ensures that any increase in muscle work is precisely matched by increases in oxygen delivery. Therefore, understanding the control mechanisms of skeletal muscle blood flow regulation is of great biological...... in the regulation of exercise hyperemia. Furthermore, blood flow to contracting leg skeletal muscles is reduced both in essential hypertension and with aging. The potential difference in vasoactive system(s) responsible for the reduction in blood flow in the two conditions is in agreement with the suggestion...

  17. The application of functional MRI in evaluating ischemic injuries of lower limb skeletal muscle

    International Nuclear Information System (INIS)

    Xia Caifeng; Gu Jianping

    2011-01-01

    The ischemic injury of lower limb skeletal muscle is caused by various reasons that lead to limb arterial blood flow insufficiency and subsequent muscle tissue hypoxia. Exact and correct evaluation of the ischemic degree of the skeletal muscle is very important for the physicians to guide the clinical treatment, to assess the therapeutic effect and to judge the prognosis. With the development and updating of scanning hardware and software, together with the use of diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), perfusion-weighted imaging (PWI), blood oxygen level dependent (BOLD) imaging and magnetic resonance spectroscopy (MRS), etc. the application of MRI has been dramatically expanded both in clinical practice and scientific researches. Nowadays, functional MRI can accurately reflect the physiological structures and pathologic changes in detail. This article aims mainly to make a comprehensive review about the application of these techniques in assessing the ischemic injuries of lower limb skeletal muscle. (authors)

  18. Live imaging of muscles in Drosophila metamorphosis: Towards high-throughput gene identification and function analysis.

    Science.gov (United States)

    Puah, Wee Choo; Wasser, Martin

    2016-03-01

    Time-lapse microscopy in developmental biology is an emerging tool for functional genomics. Phenotypic effects of gene perturbations can be studied non-invasively at multiple time points in chronological order. During metamorphosis of Drosophila melanogaster, time-lapse microscopy using fluorescent reporters allows visualization of alternative fates of larval muscles, which are a model for the study of genes related to muscle wasting. While doomed muscles enter hormone-induced programmed cell death, a smaller population of persistent muscles survives to adulthood and undergoes morphological remodeling that involves atrophy in early, and hypertrophy in late pupation. We developed a method that combines in vivo imaging, targeted gene perturbation and image analysis to identify and characterize genes involved in muscle development. Macrozoom microscopy helps to screen for interesting muscle phenotypes, while confocal microscopy in multiple locations over 4-5 days produces time-lapse images that are used to quantify changes in cell morphology. Performing a similar investigation using fixed pupal tissues would be too time-consuming and therefore impractical. We describe three applications of our pipeline. First, we show how quantitative microscopy can track and measure morphological changes of muscle throughout metamorphosis and analyze genes involved in atrophy. Second, our assay can help to identify genes that either promote or prevent histolysis of abdominal muscles. Third, we apply our approach to test new fluorescent proteins as live markers for muscle development. We describe mKO2 tagged Cysteine proteinase 1 (Cp1) and Troponin-I (TnI) as examples of proteins showing developmental changes in subcellular localization. Finally, we discuss strategies to improve throughput of our pipeline to permit genome-wide screens in the future. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Development of a functional food or drug against unloading-mediated muscle atrophy

    Science.gov (United States)

    Nikawa, Takeshi; Nakao, Reiko; Kagawa, Sachiko; Yamada, Chiharu; Abe, Manami; Tamura, Seiko; Kohno, Shohei; Sukeno, Akiko; Hirasaka, Katsuya; Okumura, Yuushi; Ishidoh, Kazumi

    The ubiquitin-proteasome pathway is a primary regulator of muscle protein turnover, providing a mechanism for selective degradation of regulatory and structural proteins. This pathway is constitutively active in muscle fibers and mediates both intracellular signaling events and normal muscle protein turnover. However, conditions of decreased muscle use, so called unloading, remarkably stimulate activity of this pathway, resulting in loss of muscle protein. In fact, we previously reported that expression of several ubiquitin ligase genes, such as MuRF-1, Cbl-b, and Siah-1A, which are rate-limiting enzymes of the ubiquitin-proteasome proteolytic pathway, are significantly up-regulated in rat skeletal muscle during spaceflight. Moreover, we found that Cbl-b-mediated ubiquitination and degradation of IRS-1, an important intermediates of IGF-1 signal transduction, contributes to muscle atrophy during unloading. Therefore, we hypothesized that inhibition of Cbl-b-mediated ubiquitination and degradation of IRS-1 leads to prevention of muscle atrophy during unloading. In this study, we aimed to evaluate oligopeptide as an inhibitor against ubiquitination of IRS-1 by Cbl-b. We synthesized various oligopeptides that may competitively inhibit the binding of Cbl-b to IRS-1 on the basis of their structures and screened inhibitory effects of these synthesized oligopeptides on Cbl-b-mediated ubiquitination of IRS-1 using in vitro ubiquitination systems. We found that two synthetic oligopeptides with specific amino acid sequences effectively inhibited interaction with Cbl-b and IRS-1, resulting in decreased ubiquitination and degradation of IRS-1 (Patent pending). In contrast, we also found inhibitory activity against Cbl-b-mediated ubiquitination of IRS-1 in soy protein-derived oligopeptides, whereas their inhibitory effects were weaker than those of synthetic oligopeptides. Our results suggest that specific oligopeptides may be available as a functional food against the muscle

  20. Functional Task Test: 3. Skeletal Muscle Performance Adaptations to Space Flight

    Science.gov (United States)

    Ryder, Jeffrey W.; Wickwire, P. J.; Buxton, R. E.; Bloomberg, J. J.; Ploutz-Snyder, L.

    2011-01-01

    The functional task test is a multi-disciplinary study investigating how space-flight induced changes to physiological systems impacts functional task performance. Impairment of neuromuscular function would be expected to negatively affect functional performance of crewmembers following exposure to microgravity. This presentation reports the results for muscle performance testing in crewmembers. Functional task performance will be presented in the abstract "Functional Task Test 1: sensory motor adaptations associated with postflight alternations in astronaut functional task performance." METHODS: Muscle performance measures were obtained in crewmembers before and after short-duration space flight aboard the Space Shuttle and long-duration International Space Station (ISS) missions. The battery of muscle performance tests included leg press and bench press measures of isometric force, isotonic power and total work. Knee extension was used for the measurement of central activation and maximal isometric force. Upper and lower body force steadiness control were measured on the bench press and knee extension machine, respectively. Tests were implemented 60 and 30 days before launch, on landing day (Shuttle crew only), and 6, 10 and 30 days after landing. Seven Space Shuttle crew and four ISS crew have completed the muscle performance testing to date. RESULTS: Preliminary results for Space Shuttle crew reveal significant reductions in the leg press performance metrics of maximal isometric force, power and total work on R+0 (pperformance metrics were observed in returning Shuttle crew and these adaptations are likely contributors to impaired functional tasks that are ambulatory in nature (See abstract Functional Task Test: 1). Interestingly, no significant changes in central activation capacity were detected. Therefore, impairments in muscle function in response to short-duration space flight are likely myocellular rather than neuromotor in nature.

  1. Resistance training improves muscle strength and functional capacity in multiple sclerosis

    DEFF Research Database (Denmark)

    Dalgas, U; Stenager, E; Jakobsen, J

    2009-01-01

    strength and functional capacity in patients with multiple sclerosis, the effects persisting after 12 weeks of self-guided physical activity. Level of evidence: The present study provides level III evidence supporting the hypothesis that lower extremity progressive resistance training can improve muscle......OBJECTIVE: To test the hypothesis that lower extremity progressive resistance training (PRT) can improve muscle strength and functional capacity in patients with multiple sclerosis (MS) and to evaluate whether the improvements are maintained after the trial. METHODS: The present study was a 2-arm...... and was afterward encouraged to continue training. After the trial, the control group completed the PRT intervention. Both groups were tested before and after 12 weeks of the trial and at 24 weeks (follow-up), where isometric muscle strength of the knee extensors (KE MVC) and functional capacity (FS; combined score...

  2. Age-related functional changes and susceptibility to eccentric contraction-induced damage in skeletal muscle cell.

    Science.gov (United States)

    Choi, Seung-Jun

    2016-09-01

    Depending upon external loading conditions, skeletal muscles can either shorten, lengthen, or remain at a fixed length as they produce force. Fixed-end or isometric contractions stabilize joints and allow muscles to act as active struts during locomotion. Active muscles dissipate energy when they are lengthened by an external force that exceeds their current force producing capacity. These unaccustomed eccentric activities often lead to muscle weakness, soreness, and inflammation. During aging, the ability to produce force under these conditions is reduced and appears to be due to not only reductions in muscle mass but also to alterations in the basic mechanisms of contraction. These alterations include impairments in the excitation-contraction process, and the action of the cross-bridges. Also, it is well known that age-related skeletal muscle atrophy is characterized by a preferential atrophy of fast fibers, and increased susceptibility to fast muscle fiber when aged muscles are exposed to eccentric contraction followed by the impaired recovery process has been reported. Taken together, the selective loss of fast muscle fiber in aged muscle could be affected by eccentric-induced muscle damage, which has significant implication to identify the etiology of the age-related functional changes. Therefore, in this review the alteration of age-related muscle function and its impact to/of eccentric induced muscle damage and recovery will be addressed in detail.

  3. Age-related functional changes and susceptibility to eccentric contraction-induced damage in skeletal muscle cell

    Directory of Open Access Journals (Sweden)

    Seung-Jun Choi

    2016-09-01

    Full Text Available Depending upon external loading conditions, skeletal muscles can either shorten, lengthen, or remain at a fixed length as they produce force. Fixed-end or isometric contractions stabilize joints and allow muscles to act as active struts during locomotion. Active muscles dissipate energy when they are lengthened by an external force that exceeds their current force producing capacity. These unaccustomed eccentric activities often lead to muscle weakness, soreness, and inflammation. During aging, the ability to produce force under these conditions is reduced and appears to be due to not only reductions in muscle mass but also to alterations in the basic mechanisms of contraction. These alterations include impairments in the excitation–contraction process, and the action of the cross-bridges. Also, it is well known that age-related skeletal muscle atrophy is characterized by a preferential atrophy of fast fibers, and increased susceptibility to fast muscle fiber when aged muscles are exposed to eccentric contraction followed by the impaired recovery process has been reported. Taken together, the selective loss of fast muscle fiber in aged muscle could be affected by eccentric-induced muscle damage, which has significant implication to identify the etiology of the age-related functional changes. Therefore, in this review the alteration of age-related muscle function and its impact to/of eccentric induced muscle damage and recovery will be addressed in detail.

  4. Premature loss of muscle mass and function in type 2 diabetes.

    Science.gov (United States)

    Guerrero, N; Bunout, D; Hirsch, S; Barrera, G; Leiva, L; Henríquez, S; De la Maza, M P

    2016-07-01

    Muscle mass and function are among the most relevant factors that contribute to an optimal quality of life, and are strong predictors of mortality in the elderly. Loss of lean tissues and deterioration of muscle function have been described as one of the many complications of type 2 diabetes mellitus (DM2), but most studies do not isolate age as an intervening factor. To study whether adult DM2 patients up to 60years of age have decreased muscle mass and function compared with healthy non-diabetic (ND) subjects of similar age. Appendicular fat-free mass (ApFFM) by dual X-ray absorptiometry (DEXA), handgrip strength (HS), quadriceps strength (QS), 12 min walking capacity (12MW) and the Timed Up and Go test (TUG) were measured in 100 DM2 patients and 39 ND controls. Muscle quality, or the ratio between lean mass and muscle strength of upper and lower limbs, and the functional limitations associated with pain and stiffness assessed according to the Western Ontario and McMaster Universities Arthrosis Index (WOMAC) were also recorded. Specific tests were performed to rule out microvascular diabetic complications (retinal and peripheral nerves), metabolic control, kidney function and vitamin D status and examine their association with ApFFM and function. ApFFM was significantly higher among DM2 female patients and lower among diabetic men. However opposite results were obtained when individual values were corrected for body mass index (BMI), specifically among women, who were more likely to be obese. As for muscle strength and global functionality tests, significantly better performances in TUG, 12MW, QS and HS were observed among ND subjects of both sexes. These differences prevailed even after excluding diabetic patients with microvascular complications as well as those with more than 10years of diabetes. Muscle quality was also significantly better among ND women. Higher scores of pain and stiffness in the WOMAC scale correlated with 12MW and TUG in both groups but

  5. Regulation and functions of the lms homeobox gene during development of embryonic lateral transverse muscles and direct flight muscles in Drosophila.

    Directory of Open Access Journals (Sweden)

    Dominik Müller

    Full Text Available BACKGROUND: Patterning and differentiation of developing musculatures require elaborate networks of transcriptional regulation. In Drosophila, significant progress has been made into identifying the regulators of muscle development and defining their interactive networks. One major family of transcription factors involved in these processes consists of homeodomain proteins. In flies, several members of this family serve as muscle identity genes to specify the fates of individual muscles, or groups thereof, during embryonic and/or adult muscle development. Herein, we report on the expression and function of a new Drosophila homeobox gene during both embryonic and adult muscle development. METHODOLOGY/PRINCIPAL FINDINGS: The newly described homeobox gene, termed lateral muscles scarcer (lms, which has yet uncharacterized orthologs in other invertebrates and primitive chordates but not in vertebrates, is expressed exclusively in subsets of developing muscle tissues. In embryos, lms is expressed specifically in the four lateral transverse (LT muscles and their founder cells in each hemisegment, whereas in larval wing imaginal discs, it is expressed in myoblasts that develop into direct flight muscles (DFMs, which are important for proper wing positioning. We have analyzed the regulatory inputs of various other muscle identity genes with overlapping or complementary expression patterns towards the cell type specific regulation of lms expression. Further we demonstrate that lms null mutants exhibit reduced numbers of embryonic LT muscles, and null mutant adults feature held-out-wing phenotypes. We provide a detailed description of the pattern and morphology of the direct flight muscles in the wild type and lms mutant flies by using the recently-developed ultramicroscopy and show that, in the mutants, all DFMs are present and present normal morphologies. CONCLUSIONS/SIGNIFICANCE: We have identified the homeobox gene lms as a new muscle identity gene

  6. Virtual Agonist-antagonist Mechanisms Produce Biological Muscle-like Functions: An Application for Robot Joint Control

    DEFF Research Database (Denmark)

    Xiong, Xiaofeng; Wörgötter, Florentin; Manoonpong, Poramate

    2014-01-01

    Purpose – Biological muscles of animals have a surprising variety of functions, i.e., struts, springs, and brakes. According to this, the purpose of this paper is to apply virtual agonist-antagonist mechanisms to robot joint control allowing for muscle-like functions and variably compliant joint......, variably compliant joint motions can be produced without mechanically bulky and complex mechanisms or complex force/toque sensing at each joint. Moreover, through tuning the damping coefficient of the VAAM, the functions of the VAAM are comparable to biological muscles. Originality/value – The model (i.......e., VAAM) provides a way forward to emulate muscle-like functions that are comparable to those found in physiological experiments of biological muscles. Based on these muscle-like functions, the robotic joints can easily achieve variable compliance that does not require complex physical components...

  7. Poloxamer [corrected] 188 has a deleterious effect on dystrophic skeletal muscle function.

    Directory of Open Access Journals (Sweden)

    Rebecca L Terry

    Full Text Available Duchenne muscular dystrophy (DMD is an X-linked, fatal muscle wasting disease for which there is currently no cure and limited palliative treatments. Poloxomer 188 (P188 is a tri-block copolymer that has been proposed as a potential treatment for cardiomyopathy in DMD patients. Despite the reported beneficial effects of P188 on dystrophic cardiac muscle function, the effects of P188 on dystrophic skeletal muscle function are relatively unknown. Mdx mice were injected intraperitoneally with 460 mg/kg or 30 mg/kg P188 dissolved in saline, or saline alone (control. The effect of single-dose and 2-week daily treatment was assessed using a muscle function test on the Tibialis Anterior (TA muscle in situ in anaesthetised mice. The test comprises a warm up, measurement of the force-frequency relationship and a series of eccentric contractions with a 10% stretch that have previously been shown to cause a drop in maximum force in mdx mice. After 2 weeks of P188 treatment at either 30 or 460 mg/kg/day the drop in maximum force produced following eccentric contractions was significantly greater than that seen in saline treated control mice (P = 0.0001. Two week P188 treatment at either dose did not significantly change the force-frequency relationship or maximum isometric specific force produced by the TA muscle. In conclusion P188 treatment increases susceptibility to contraction-induced injury following eccentric contractions in dystrophic skeletal muscle and hence its suitability as a potential therapeutic for DMD should be reconsidered.

  8. PDE5 inhibition alleviates functional muscle ischemia in boys with Duchenne muscular dystrophy.

    Science.gov (United States)

    Nelson, Michael D; Rader, Florian; Tang, Xiu; Tavyev, Jane; Nelson, Stanley F; Miceli, M Carrie; Elashoff, Robert M; Sweeney, H Lee; Victor, Ronald G

    2014-06-10

    To determine whether phosphodiesterase type 5 (PDE5) inhibition can alleviate exercise-induced skeletal muscle ischemia in boys with Duchenne muscular dystrophy (DMD). In 10 boys with DMD and 10 healthy age-matched male controls, we assessed exercise-induced attenuation of reflex sympathetic vasoconstriction, i.e., functional sympatholysis, a protective mechanism that matches oxygen delivery to metabolic demand. Reflex vasoconstriction was induced by simulated orthostatic stress, measured as the decrease in forearm muscle oxygenation with near-infrared spectroscopy, and performed when the forearm muscles were rested or lightly exercised with rhythmic handgrip exercise. Then, the patients underwent an open-label, dose-escalation, crossover trial with single oral doses of tadalafil or sildenafil. The major new findings are 2-fold: first, sympatholysis is impaired in boys with DMD-producing functional muscle ischemia-despite contemporary background therapy with corticosteroids alone or in combination with cardioprotective medication. Second, PDE5 inhibition with standard clinical doses of either tadalafil or sildenafil alleviates this ischemia in a dose-dependent manner. Furthermore, PDE5 inhibition also normalizes the exercise-induced increase in skeletal muscle blood flow (measured by Doppler ultrasound), which is markedly blunted in boys with DMD. These data provide in-human proof of concept for PDE5 inhibition as a putative new therapeutic strategy for DMD. This study provides Class IV evidence that in patients with DMD, PDE5 inhibition restores functional sympatholysis. © 2014 American Academy of Neurology.

  9. Response of mitochondrial function to hypothyroidism in normal and regenerated rat skeletal muscle.

    Science.gov (United States)

    Zoll, J; Ventura-Clapier, R; Serrurier, B; Bigard, A X

    2001-01-01

    Although thyroid hormones induce a well known decrease in muscle oxidative capacity, nothing is known concerning their effects on mitochondrial function and regulation in situ. Similarly, the influence of regeneration process is not completely understood. We investigated the effects of hypothyroidism on mitochondrial function in fast gastrocnemius (GS) and slow soleus (SOL) muscles either intact or having undergone a cycle of degeneration/regeneration (Rg SOL) following a local injection of myotoxin. Thyroid hormone deficiency was induced by thyroidectomy and propylthiouracyl via drinking water. Respiration was measured in muscle fibres permeabilised by saponin in order to assess the oxidative capacity of the muscles and the regulation of mitochondria in situ. Oxidative capacities were 8.9 in SOL, 8.5 in Rg SOL and 5.9 micromol O2/min/g dry weight in GS and decreased by 52, 42 and 39% respectively (P hypothyroid rats. Moreover, the Km of mitochondrial respiration for the phosphate acceptor ADP exhibited a two-fold decrease in Rg SOL and intact SOL by hypothyroidism (P hypothyroidism markedly altered the sensitivity of mitochondrial respiration to ADP but not to creatine in SOL muscles, suggesting that mitochondrial regulation could be partially controlled by thyroid hormones. On the other hand, mitochondrial function completely recovered following regeneration/degeneration, suggesting that thyroid hormones are not involved in the regeneration process per se.

  10. Initial intramuscular perfusion pressure predicts early skeletal muscle function following isolated tibial fractures

    Directory of Open Access Journals (Sweden)

    Haas Norbert P

    2008-04-01

    Full Text Available Abstract Background The severity of associated soft tissue trauma in complex injuries of the extremities guides fracture treatment and decisively determines patient's prognosis. Trauma-induced microvascular dysfunction and increased tissue pressure is known to trigger secondary soft tissue damage and seems to adversely affect skeletal muscle function. Methods 20 patients with isolated tibial fractures were included. Blood pressure and compartment pressure (anterior and deep posterior compartment were measured continuously up to 24 hours. Corresponding perfusion pressure was calculated. After 4 and 12 weeks isokinetic muscle peak torque and mean power of the ankle joint in dorsal and plantar flexion were measured using a Biodex dynamometer. Results A significant inverse correlation between the anterior perfusion pressure at 24 hours and deficit in dorsiflexion at 4 weeks was found for both, the peak torque (R = -0.83; p Conclusion The functional relationship between the decrease in intramuscular perfusion pressures and muscle performance in the early rehabilitation period indicate a causative and prognostic role of early posttraumatic microcirculatory derangements and skeletal muscle function. Therapeutic concepts aimed at effective muscle recovery, early rehabilitation, and decreased secondary tissue damage, should consider the maintenance of an adequate intramuscular perfusion pressure.

  11. Target genes of myostatin loss-of-function in muscles of late bovine fetuses

    Directory of Open Access Journals (Sweden)

    Hocquette Jean-François

    2007-03-01

    Full Text Available Abstract Background Myostatin, a muscle-specific member of the Transforming Growth Factor beta family, negatively regulates muscle development. Double-muscled (DM cattle have a loss-of-function mutation in their myostatin gene responsible for the hypermuscular phenotype. Thus, these animals are a good model for understanding the mechanisms underpinning muscular hypertrophy. In order to identify individual genes or networks that may be myostatin targets, we looked for genes that were differentially expressed between DM and normal (NM animals (n = 3 per group in the semitendinosus muscle (hypertrophied in DM animals at 260 days of fetal development (when the biochemical differentiation of muscle is intensive. A heterologous microarray (human and murine oligonucleotide sequences of around 6,000 genes expressed in muscle was used. Results Many genes were found to be differentially expressed according to genetic type (some with a more than 5-fold change, and according to the presence of one or two functional myostatin allele(s. They belonged to various functional categories. The genes down-regulated in DM fetuses were mainly those encoding extracellular matrix proteins, slow contractile proteins and ribosomal proteins. The genes up-regulated in DM fetuses were mainly involved in the regulation of transcription, cell cycle/apoptosis, translation or DNA metabolism. These data highlight features indicating that DM muscle is shifted towards a more glycolytic metabolism, and has an altered extracellular matrix composition (e.g. down-regulation of COL1A1 and COL1A2, and up-regulation of COL4A2 and decreased adipocyte differentiation (down-regulation of C1QTNF3. The altered gene expression in the three major muscle compartments (fibers, connective tissue and intramuscular adipose tissue is consistent with the well-known characteristics of DM cattle. In addition, novel potential targets of the myostatin gene were identified (MB, PLN, troponins, ZFHX1B

  12. Characterization of the equine skeletal muscle transcriptome identifies novel functional responses to exercise training.

    LENUS (Irish Health Repository)

    McGivney, Beatrice A

    2010-01-01

    BACKGROUND: Digital gene expression profiling was used to characterize the assembly of genes expressed in equine skeletal muscle and to identify the subset of genes that were differentially expressed following a ten-month period of exercise training. The study cohort comprised seven Thoroughbred racehorses from a single training yard. Skeletal muscle biopsies were collected at rest from the gluteus medius at two time points: T(1) - untrained, (9 +\\/- 0.5 months old) and T(2) - trained (20 +\\/- 0.7 months old). RESULTS: The most abundant mRNA transcripts in the muscle transcriptome were those involved in muscle contraction, aerobic respiration and mitochondrial function. A previously unreported over-representation of genes related to RNA processing, the stress response and proteolysis was observed. Following training 92 tags were differentially expressed of which 74 were annotated. Sixteen genes showed increased expression, including the mitochondrial genes ACADVL, MRPS21 and SLC25A29 encoded by the nuclear genome. Among the 58 genes with decreased expression, MSTN, a negative regulator of muscle growth, had the greatest decrease.Functional analysis of all expressed genes using FatiScan revealed an asymmetric distribution of 482 Gene Ontology (GO) groups and 18 KEGG pathways. Functional groups displaying highly significant (P < 0.0001) increased expression included mitochondrion, oxidative phosphorylation and fatty acid metabolism while functional groups with decreased expression were mainly associated with structural genes and included the sarcoplasm, laminin complex and cytoskeleton. CONCLUSION: Exercise training in Thoroughbred racehorses results in coordinate changes in the gene expression of functional groups of genes related to metabolism, oxidative phosphorylation and muscle structure.

  13. Muscle function and fatigability of trunk flexors in males and females.

    Science.gov (United States)

    Deering, Rita E; Senefeld, Jonathon W; Pashibin, Tatyana; Neumann, Donald A; Hunter, Sandra K

    2017-01-01

    Optimal function of the abdominal muscles is necessary for several life functions including lifting and carrying tasks. Sex differences in strength and fatigability are established for many limb muscles and back extensor muscles, but it is unknown if sex differences exist for the abdominal muscles despite their functional importance. Eighteen females (24.3 ± 4.8 years) and 15 males (24.1 ± 6.6 years) performed (1) isometric trunk flexion maximal voluntary contractions (MVCs) in a range of trunk positions to establish a torque-angle curve and (2) submaximal (50% MVC), intermittent isometric contraction (6 s on, 4 s off) until task failure to determine fatigability of the trunk flexor muscles. Dual X-ray absorptiometry quantified body fat and lean mass. Physical activity levels were quantified with a questionnaire. Torque-angle curves, electromyography (EMG), MVC torque, and torque steadiness were compared with repeated measures ANOVA with sex as a between-subjects factor. For the torque-angle curve, MVC torque was reduced as the trunk angle increased toward flexion ( p    0.05). Time-to-task failure for the submaximal fatigability task in upright sitting was similar between males and females (12.4 ± 7 vs 10.5 ± 6 min). Time-to-task failure was positively associated with strength ( r  = 0.473, p  = 0.005) and self-reported physical activity ( r  = 0.456, p  = 0.030). Lean mass in the trunk was positively associated with trunk flexor strength ( r  = 0.378, p  = 0.011) and self-reported physical activity ( r  = 0.486, p  = 0.007). Finally, torque steadiness [coefficient of variation of torque (CV)] during submaximal isometric contractions decreased with contraction intensity and was similar for males and females across all intensities. Unlike many limb muscle groups, males and females had similar fatigability and torque steadiness of the trunk flexor muscles during isometric contractions. Stronger individuals

  14. Molecules in motion: influences of diffusion on metabolic structure and function in skeletal muscle.

    Science.gov (United States)

    Kinsey, Stephen T; Locke, Bruce R; Dillaman, Richard M

    2011-01-15

    Metabolic processes are often represented as a group of metabolites that interact through enzymatic reactions, thus forming a network of linked biochemical pathways. Implicit in this view is that diffusion of metabolites to and from enzymes is very fast compared with reaction rates, and metabolic fluxes are therefore almost exclusively dictated by catalytic properties. However, diffusion may exert greater control over the rates of reactions through: (1) an increase in reaction rates; (2) an increase in diffusion distances; or (3) a decrease in the relevant diffusion coefficients. It is therefore not surprising that skeletal muscle fibers have long been the focus of reaction-diffusion analyses because they have high and variable rates of ATP turnover, long diffusion distances, and hindered metabolite diffusion due to an abundance of intracellular barriers. Examination of the diversity of skeletal muscle fiber designs found in animals provides insights into the role that diffusion plays in governing both rates of metabolic fluxes and cellular organization. Experimental measurements of metabolic fluxes, diffusion distances and diffusion coefficients, coupled with reaction-diffusion mathematical models in a range of muscle types has started to reveal some general principles guiding muscle structure and metabolic function. Foremost among these is that metabolic processes in muscles do, in fact, appear to be largely reaction controlled and are not greatly limited by diffusion. However, the influence of diffusion is apparent in patterns of fiber growth and metabolic organization that appear to result from selective pressure to maintain reaction control of metabolism in muscle.

  15. Renin-angiotensin system: an old player with novel functions in skeletal muscle.

    Science.gov (United States)

    Cabello-Verrugio, Claudio; Morales, María Gabriela; Rivera, Juan Carlos; Cabrera, Daniel; Simon, Felipe

    2015-05-01

    Skeletal muscle is a tissue that shows the most plasticity in the body; it can change in response to physiological and pathological stimuli. Among the diseases that affect skeletal muscle are myopathy-associated fibrosis, insulin resistance, and muscle atrophy. A common factor in these pathologies is the participation of the renin-angiotensin system (RAS). This system can be functionally separated into the classical and nonclassical RAS axis. The main components of the classical RAS pathway are angiotensin-converting enzyme (ACE), angiotensin II (Ang-II), and Ang-II receptors (AT receptors), whereas the nonclassical axis is composed of ACE2, angiotensin 1-7 [Ang (1-7)], and the Mas receptor. Hyperactivity of the classical axis in skeletal muscle has been associated with insulin resistance, atrophy, and fibrosis. In contrast, current evidence supports the action of the nonclassical RAS as a counter-regulator axis of the classical RAS pathway in skeletal muscle. In this review, we describe the mechanisms involved in the pathological effects of the classical RAS, advances in the use of pharmacological molecules to inhibit this axis, and the beneficial effects of stimulation of the nonclassical RAS pathway on insulin resistance, atrophy, and fibrosis in skeletal muscle. © 2015 Wiley Periodicals, Inc.

  16. Overexpression of IGF-1 attenuates skeletal muscle damage and accelerates muscle regeneration and functional recovery after disuse

    Science.gov (United States)

    Ye, Fan; Mathur, Sunita; Liu, Min; Borst, Stephen E.; Walter, Glenn A.; Sweeney, H. Lee; Vandenborne, Krista

    2014-01-01

    Skeletal muscle is a highly dynamic tissue that responds to endogenous and external stimuli, including alterations in mechanical loading and growth factors. In particular, the antigravity soleus muscle experiences significant muscle atrophy during disuse and extensive muscle damage upon reloading. Since insulin-like growth factor-1 (IGF-1) has been implicated as a central regulator of muscle repair and modulation of muscle size, we examined the effect of viral mediated overexpression of IGF-1 on the soleus muscle following hindlimb cast immobilization and upon reloading. Recombinant IGF-1 cDNA virus was injected into one of the posterior hindlimbs of the mice, while the contralateral limb was injected with saline (control). At 20 weeks of age, both hindlimbs were immobilized for two weeks to induce muscle atrophy in the soleus and ankle plantar flexor muscle group. Subsequently, the mice were allowed to reambulate and muscle damage and recovery was monitored over a period of 2 to 21 days. The primary finding of this study was that IGF-1 overexpression attenuated reloading-induced muscle damage in the soleus muscle, and accelerated muscle regeneration and force recovery. Muscle T2 assessed by MRI, a nonspecific marker of muscle damage, was significantly lower in IGF-1 injected, compared to contralateral soleus muscles at 2 and 5 days reambulation (P<0.05). The reduced prevalence of muscle damage in IGF-1 injected soleus muscles was confirmed on histology, with a lower fraction area of abnormal muscle tissue in IGF-I injected muscles at 2 days reambulation (33.2±3.3%vs 54.1±3.6%, P<0.05). Evidence of the effect of IGF-1 on muscle regeneration included timely increases in the number of central nuclei (21% at 5 days reambulation), paired-box transcription factor 7 (36% at 5 days), embryonic myosin (37% at 10 days), and elevated MyoD mRNA (7-fold at 2 days) in IGF-1 injected limbs (P<0.05). These findings demonstrate a potential role of IGF-1 in protecting unloaded

  17. Evaluation of jaw and neck muscle activities while chewing using EMG-EMG transfer function and EMG-EMG coherence function analyses in healthy subjects.

    Science.gov (United States)

    Ishii, Tomohiro; Narita, Noriyuki; Endo, Hiroshi

    2016-06-01

    This study aims to quantitatively clarify the physiological features in rhythmically coordinated jaw and neck muscle EMG activities while chewing gum using EMG-EMG transfer function and EMG-EMG coherence function analyses in 20 healthy subjects. The chewing side masseter muscle EMG signal was used as the reference signal, while the other jaw (non-chewing side masseter muscle, bilateral anterior temporal muscles, and bilateral anterior digastric muscles) and neck muscle (bilateral sternocleidomastoid muscles) EMG signals were used as the examined signals in EMG-EMG transfer function and EMG-EMG coherence function analyses. Chewing-related jaw and neck muscle activities were aggregated in the first peak of the power spectrum in rhythmic chewing. The gain in the peak frequency represented the power relationships between jaw and neck muscle activities during rhythmic chewing. The phase in the peak frequency represented the temporal relationships between the jaw and neck muscle activities, while the non-chewing side neck muscle presented a broad range of distributions across jaw closing and opening phases. Coherence in the peak frequency represented the synergistic features in bilateral jaw closing muscles and chewing side neck muscle activities. The coherence and phase in non-chewing side neck muscle activities exhibited a significant negative correlation. From above, the bilateral coordination between the jaw and neck muscle activities is estimated while chewing when the non-chewing side neck muscle is synchronously activated with the jaw closing muscles, while the unilateral coordination is estimated when the non-chewing side neck muscle is irregularly activated in the jaw opening phase. Thus, the occurrence of bilateral or unilateral coordinated features in the jaw and neck muscle activities may correspond to the phase characteristics in the non-chewing side neck muscle activities during rhythmical chewing. Considering these novel findings in healthy subjects, EMG

  18. Aging impairs the recovery in mechanical muscle function following 4 days of disuse

    DEFF Research Database (Denmark)

    Hvid, L G; Suetta, C; Nielsen, J H

    2014-01-01

    As aged individuals are frequently exposed to short-term disuse caused by disease or musculoskeletal injury, it is important to understand how short-term disuse and subsequent retraining affect lower limb mechanical muscle function. The purpose of the present study was, therefore, to investigate...... the effect of 4 days of lower limb disuse followed by 7 days of active recovery on mechanical muscle function of the knee extensors in young (24.3±0.9 years, n=11) and old (67.2±1.0 years, n=11) recreationally active healthy males. Slow and moderate dynamic muscle strength were assessed using isokinetic...... to disuse, marked age-related differences (p

  19. Resistance training for activity limitations in older adults with skeletal muscle function deficits: a systematic review

    Directory of Open Access Journals (Sweden)

    Papa EV

    2017-06-01

    Full Text Available Evan V Papa,1 Xiaoyang Dong,2 Mahdi Hassan1 1Department of Rehabilitation Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, People’s Republic of China; 2Department of Physical Therapy, University of North Texas Health Science Center, Fort Worth, TX, USA Abstract: Human aging results in a variety of changes to skeletal muscle. Sarcopenia is the age-associated loss of muscle mass and is one of the main contributors to musculoskeletal impairments in the elderly. Previous research has demonstrated that resistance training can attenuate skeletal muscle function deficits in older adults, however few articles have focused on the effects of resistance training on functional mobility. The purpose of this systematic review was to 1 present the current state of literature regarding the effects of resistance training on functional mobility outcomes for older adults with skeletal muscle function deficits and 2 provide clinicians with practical guidelines that can be used with seniors during resistance training, or to encourage exercise. We set forth evidence that resistance training can attenuate age-related changes in functional mobility, including improvements in gait speed, static and dynamic balance, and fall risk reduction. Older adults should be encouraged to participate in progressive resistance training activities, and should be admonished to move along a continuum of exercise from immobility, toward the recommended daily amounts of activity. Keywords: aging, strength training, sarcopenia, mobility, balance

  20. Identification of Histone Deacetylase 2 as a Functional Gene for Skeletal Muscle Development in Chickens

    Directory of Open Access Journals (Sweden)

    Md. Shahjahan

    2016-04-01

    Full Text Available A previous genome-wide association study (GWAS exposed histone deacetylase 2 (HDAC2 as a possible candidate gene for breast muscle weight in chickens. The present research has examined the possible role of HDAC2 in skeletal muscle development in chickens. Gene expression was measured by quantitative polymerase chain reaction in breast and thigh muscles during both embryonic (four ages and post-hatch (five ages development and in cultures of primary myoblasts during both proliferation and differentiation. The expression of HDAC2 increased significantly across embryonic days (ED in breast (ED 14, 16, 18, and 21 and thigh (ED 14 and 18, and ED 14 and 21 muscles suggesting that it possibly plays a role in myoblast hyperplasia in both breast and thigh muscles. Transcript abundance of HDAC2 identified significantly higher in fast growing muscle than slow growing in chickens at d 90 of age. Expression of HDAC2 during myoblast proliferation in vitro declined between 24 h and 48 h when expression of the marker gene paired box 7 (PAX7 increased and cell numbers increased throughout 72 h of culture. During induced differentiation of myoblasts to myotubes, the abundance of HDAC2 and the marker gene myogenic differentiation 1 (MYOD1, both increased significantly. Taken together, it is suggested that HDAC2 is most likely involved in a suppressive fashion in myoblast proliferation and may play a positive role in myoblast differentiation. The present results confirm the suggestion that HDAC2 is a functional gene for pre-hatch and post-hatch (fast growing muscle development of chicken skeletal muscle.

  1. ALTERATION OF MUSCLE FUNCTION AFTER ELECTRICAL STIMULATION BOUT OF KNEE EXTENSORS AND FLEXORS

    Directory of Open Access Journals (Sweden)

    Marc Vanderthommen

    2012-12-01

    Full Text Available The purpose was to study the effects on muscle function of an electrical stimulation bout applied unilaterally on thigh muscles in healthy male volunteers. One group (ES group, n = 10 received consecutively 100 isometric contractions of quadriceps and 100 isometric contractions of hamstrings (on-off ratio 6-6 s induced by neuromuscular electrical stimulations (NMES. Changes in muscle torque, muscle soreness (0-10 VAS, muscle stiffness and serum creatine kinase (CK activity were assessed before the NMES exercise (pre-ex as well as 24h (d+1, 48h (d+2 and 120h (d+5 after the bout. A second group (control group, n = 10 were submitted to the same test battery than the ES group and with the same time-frame. The between-group comparison indicated a significant increase in VAS scores and in serum levels of CK only in the ES group. In the ES group, changes were more pronounced in hamstrings than in quadriceps and peaked at d+2 (quadriceps VAS scores = 2.20 ± 1.55 a.u. (0 at pre-ex; hamstrings VAS scores = 3.15 ± 2.14 a.u. (0 at pre-ex; hip flexion angle = 62 ± 5° (75 ± 6° at pre-ex; CK activity = 3021 ± 2693 IU·l-1 (136 ± 50 IU·l-1 at pre-ex. The results of the present study suggested the occurrence of muscle damage that could have been induced by the peculiar muscle recruitment in NMES and the resulting overrated mechanical stress. The sensitivity to the damaging effects of NMES appeared higher in the hamstrings than in quadriceps muscles

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

    Science.gov (United States)

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

    2015-01-01

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

  3. Plasticity of human skeletal muscle: gene expression to in vivo function.

    Science.gov (United States)

    Harridge, Stephen D R

    2007-09-01

    Human skeletal muscle is a highly heterogeneous tissue, able to adapt to the different challenges that may be placed upon it. When overloaded, a muscle adapts by increasing its size and strength through satellite-cell-mediated mechanisms, whereby protein synthesis is increased and new nuclei are added to maintain the myonuclear domain. This process is regulated by an array of mechanical, hormonal and nutritional signals. Growth factors, such as insulin-like growth factor I (IGF-I) and testosterone, are potent anabolic agents, whilst myostatin acts as a negative regulator of muscle mass. Insulin-like growth factor I is unique in being able to stimulate both the proliferation and the differentiation of satellite cells and works as part of an important local repair and adaptive mechanism. Speed of movement, as characterized by maximal velocity of shortening (V(max)), is regulated primarily by the isoform of myosin heavy chain (MHC) contained within a muscle fibre. Human fibres can express three MHCs: MHC-I, -IIa and -IIx, in order of increasing V(max) and maximal power output. Training studies suggest that there is a subtle interplay between the MHC-IIa and -IIx isoforms, with the latter being downregulated by activity and upregulated by inactivity. However, switching between the two main isoforms appears to require significant challenges to a muscle. Upregulation of fast gene programs is caused by prolonged disuse, whilst upregulation of slow gene programs appears to require significant and prolonged activity. The potential mechanisms by which alterations in muscle composition are mediated are discussed. The implications in terms of contractile function of altering muscle phenotype are discussed from the single fibre to the whole muscle level.

  4. The Accuracy of Locating Lumbar Vertebrae When Using Palpation Versus Ultrasonography

    DEFF Research Database (Denmark)

    Mieritz, Rune Mygind; Kawchuk, Gregory Neil

    2016-01-01

    . The target was then located by 16 undergraduate chiropractic students using clinical palpation techniques learned in their academic program (with participant seated and prone) and ultrasonic imaging learned through a 5-minute training video. Presumed target locations identified by students were recorded...

  5. Multi-fingered haptic palpation utilizing granular jamming stiffness feedback actuators

    International Nuclear Information System (INIS)

    Li, Min; Sareh, Sina; Seneviratne, Lakmal D; Wurdemann, Helge A; Althoefer, Kaspar; Ranzani, Tommaso; Dasgupta, Prokar

    2014-01-01

    This paper describes a multi-fingered haptic palpation method using stiffness feedback actuators for simulating tissue palpation procedures in traditional and in robot-assisted minimally invasive surgery. Soft tissue stiffness is simulated by changing the stiffness property of the actuator during palpation. For the first time, granular jamming and pneumatic air actuation are combined to realize stiffness modulation. The stiffness feedback actuator is validated by stiffness measurements in indentation tests and through stiffness discrimination based on a user study. According to the indentation test results, the introduction of a pneumatic chamber to granular jamming can amplify the stiffness variation range and reduce hysteresis of the actuator. The advantage of multi-fingered palpation using the proposed actuators is proven by the comparison of the results of the stiffness discrimination performance using two-fingered (sensitivity: 82.2%, specificity: 88.9%, positive predicative value: 80.0%, accuracy: 85.4%, time: 4.84 s) and single-fingered (sensitivity: 76.4%, specificity: 85.7%, positive predicative value: 75.3%, accuracy: 81.8%, time: 7.48 s) stiffness feedback. (paper)

  6. Coordination of intrinsic and extrinsic hand muscle activity as a function of wrist joint angle during two-digit grasping.

    Science.gov (United States)

    Johnston, Jamie A; Bobich, Lisa R; Santello, Marco

    2010-04-26

    Fingertip forces result from the activation of muscles that cross the wrist and muscles whose origins and insertions reside within the hand (extrinsic and intrinsic hand muscles, respectively). Thus, tasks that involve changes in wrist angle affect the moment arm and length, hence the force-producing capabilities, of extrinsic muscles only. If a grasping task requires the exertion of constant fingertip forces, the Central Nervous System (CNS) may respond to changes in wrist angle by modulating the neural drive to extrinsic or intrinsic muscles only or by co-activating both sets of muscles. To distinguish between these scenarios, we recorded electromyographic (EMG) activity of intrinsic and extrinsic muscles of the thumb and index finger as a function of wrist angle during a two-digit object hold task. We hypothesized that changes in wrist angle would elicit EMG amplitude modulation of the extrinsic and intrinsic hand muscles. In one experimental condition we asked subjects to exert the same digit forces at each wrist angle, whereas in a second condition subjects could choose digit forces for holding the object. EMG activity was significantly modulated in both extrinsic and intrinsic muscles as a function of wrist angle (both pextrinsic and intrinsic muscles as a muscle synergy. These findings are discussed within the theoretical frameworks of synergies and common neural input across motor nuclei of hand muscles. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  7. Skeletal muscle magnetic resonance biomarkers correlate with function and sentinel events in Duchenne muscular dystrophy.

    Science.gov (United States)

    Barnard, Alison M; Willcocks, Rebecca J; Finanger, Erika L; Daniels, Michael J; Triplett, William T; Rooney, William D; Lott, Donovan J; Forbes, Sean C; Wang, Dah-Jyuu; Senesac, Claudia R; Harrington, Ann T; Finkel, Richard S; Russman, Barry S; Byrne, Barry J; Tennekoon, Gihan I; Walter, Glenn A; Sweeney, H Lee; Vandenborne, Krista

    2018-01-01

    To provide evidence for quantitative magnetic resonance (qMR) biomarkers in Duchenne muscular dystrophy by investigating the relationship between qMR measures of lower extremity muscle pathology and functional endpoints in a large ambulatory cohort using a multicenter study design. MR spectroscopy and quantitative imaging were implemented to measure intramuscular fat fraction and the transverse magnetization relaxation time constant (T2) in lower extremity muscles of 136 participants with Duchenne muscular dystrophy. Measures were collected at 554 visits over 48 months at one of three imaging sites. Fat fraction was measured in the soleus and vastus lateralis using MR spectroscopy, while T2 was assessed using MRI in eight lower extremity muscles. Ambulatory function was measured using the 10m walk/run, climb four stairs, supine to stand, and six minute walk tests. Significant correlations were found between all qMR and functional measures. Vastus lateralis qMR measures correlated most strongly to functional endpoints (|ρ| = 0.68-0.78), although measures in other rapidly progressing muscles including the biceps femoris (|ρ| = 0.63-0.73) and peroneals (|ρ| = 0.59-0.72) also showed strong correlations. Quantitative MR biomarkers were excellent indicators of loss of functional ability and correlated with qualitative measures of function. A VL FF of 0.40 was an approximate lower threshold of muscle pathology associated with loss of ambulation. Lower extremity qMR biomarkers have a robust relationship to clinically meaningful measures of ambulatory function in Duchenne muscular dystrophy. These results provide strong supporting evidence for qMR biomarkers and set the stage for their potential use as surrogate outcomes in clinical trials.

  8. Two weeks of muscle immobilization impairs functional sympatholysis but increases exercise hyperemia and the vasodilatory responsiveness to infused ATP

    DEFF Research Database (Denmark)

    Mortensen, Stefan P; Mørkeberg, Jakob S; Thaning, Pia

    2012-01-01

    During exercise, contracting muscles can override sympathetic vasoconstrictor activity (functional sympatholysis). ATP and adenosine have been proposed to play a role in skeletal muscle blood flow regulation. However, little is known about the role of muscle training status on functional sympatho......During exercise, contracting muscles can override sympathetic vasoconstrictor activity (functional sympatholysis). ATP and adenosine have been proposed to play a role in skeletal muscle blood flow regulation. However, little is known about the role of muscle training status on functional....../min; P higher in the immobilized leg (2.9 ± 0.2 l/min; P .... Mean arterial pressure was lower during exercise with the trained leg compared with the immobilized leg (P higher after immobilization (3.9 ± 0.3 and 4.5 ± 0.6 l/min in the control and immobilized leg...

  9. Quantification of Na+,K+ pumps and their transport rate in skeletal muscle: Functional significance

    Science.gov (United States)

    2013-01-01

    During excitation, muscle cells gain Na+ and lose K+, leading to a rise in extracellular K+ ([K+]o), depolarization, and loss of excitability. Recent studies support the idea that these events are important causes of muscle fatigue and that full use of the Na+,K+-ATPase (also known as the Na+,K+ pump) is often essential for adequate clearance of extracellular K+. As a result of their electrogenic action, Na+,K+ pumps also help reverse depolarization arising during excitation, hyperkalemia, and anoxia, or from cell damage resulting from exercise, rhabdomyolysis, or muscle diseases. The ability to evaluate Na+,K+-pump function and the capacity of the Na+,K+ pumps to fill these needs require quantification of the total content of Na+,K+ pumps in skeletal muscle. Inhibition of Na+,K+-pump activity, or a decrease in their content, reduces muscle contractility. Conversely, stimulation of the Na+,K+-pump transport rate or increasing the content of Na+,K+ pumps enhances muscle excitability and contractility. Measurements of [3H]ouabain binding to skeletal muscle in vivo or in vitro have enabled the reproducible quantification of the total content of Na+,K+ pumps in molar units in various animal species, and in both healthy people and individuals with various diseases. In contrast, measurements of 3-O-methylfluorescein phosphatase activity associated with the Na+,K+-ATPase may show inconsistent results. Measurements of Na+ and K+ fluxes in intact isolated muscles show that, after Na+ loading or intense excitation, all the Na+,K+ pumps are functional, allowing calculation of the maximum Na+,K+-pumping capacity, expressed in molar units/g muscle/min. The activity and content of Na+,K+ pumps are regulated by exercise, inactivity, K+ deficiency, fasting, age, and several hormones and pharmaceuticals. Studies on the α-subunit isoforms of the Na+,K+-ATPase have detected a relative increase in their number in response to exercise and the glucocorticoid dexamethasone but have not

  10. Quantification of Na+,K+ pumps and their transport rate in skeletal muscle: functional significance.

    Science.gov (United States)

    Clausen, Torben

    2013-10-01

    During excitation, muscle cells gain Na(+) and lose K(+), leading to a rise in extracellular K(+) ([K(+)]o), depolarization, and loss of excitability. Recent studies support the idea that these events are important causes of muscle fatigue and that full use of the Na(+),K(+)-ATPase (also known as the Na(+),K(+) pump) is often essential for adequate clearance of extracellular K(+). As a result of their electrogenic action, Na(+),K(+) pumps also help reverse depolarization arising during excitation, hyperkalemia, and anoxia, or from cell damage resulting from exercise, rhabdomyolysis, or muscle diseases. The ability to evaluate Na(+),K(+)-pump function and the capacity of the Na(+),K(+) pumps to fill these needs require quantification of the total content of Na(+),K(+) pumps in skeletal muscle. Inhibition of Na(+),K(+)-pump activity, or a decrease in their content, reduces muscle contractility. Conversely, stimulation of the Na(+),K(+)-pump transport rate or increasing the content of Na(+),K(+) pumps enhances muscle excitability and contractility. Measurements of [(3)H]ouabain binding to skeletal muscle in vivo or in vitro have enabled the reproducible quantification of the total content of Na(+),K(+) pumps in molar units in various animal species, and in both healthy people and individuals with various diseases. In contrast, measurements of 3-O-methylfluorescein phosphatase activity associated with the Na(+),K(+)-ATPase may show inconsistent results. Measurements of Na(+) and K(+) fluxes in intact isolated muscles show that, after Na(+) loading or intense excitation, all the Na(+),K(+) pumps are functional, allowing calculation of the maximum Na(+),K(+)-pumping capacity, expressed in molar units/g muscle/min. The activity and content of Na(+),K(+) pumps are regulated by exercise, inactivity, K(+) deficiency, fasting, age, and several hormones and pharmaceuticals. Studies on the α-subunit isoforms of the Na(+),K(+)-ATPase have detected a relative increase in their

  11. Chronic dietary supplementation with soy protein improves muscle function in rats.

    Directory of Open Access Journals (Sweden)

    Ramzi J Khairallah

    Full Text Available Athletes as well as elderly or hospitalized patients use dietary protein supplementation to maintain or grow skeletal muscle. It is recognized that high quality protein is needed for muscle accretion, and can be obtained from both animal and plant-based sources. There is interest to understand whether these sources differ in their ability to maintain or stimulate muscle growth and function. In this study, baseline muscle performance was assessed in 50 adult Sprague-Dawley rats after which they were assigned to one of five semi-purified "Western" diets (n = 10/group differing only in protein source, namely 19 kcal% protein from either milk protein isolate (MPI, whey protein isolate (WPI, soy protein isolate (SPI, soy protein concentrate (SPC or enzyme-treated soy protein (SPE. The diets were fed for 8 weeks at which point muscle performance testing was repeated and tissues were collected for analysis. There was no significant difference in food consumption or body weights over time between the diet groups nor were there differences in terminal organ and muscle weights or in serum lipids, creatinine or myostatin. Compared with MPI-fed rats, rats fed WPI and SPC displayed a greater maximum rate of contraction using the in vivo measure of muscle performance (p<0.05 with increases ranging from 13.3-27.5% and 22.8-29.5%, respectively at 60, 80, 100 and 150 Hz. When the maximum force was normalized to body weight, SPC-fed rats displayed increased force compared to MPI (p<0.05, whereas when normalized to gastrocnemius weight, WPI-fed rats displayed increased force compared to MPI (p<0.05. There was no difference between groups using in situ muscle performance. In conclusion, soy protein consumption, in high-fat diet, resulted in muscle function comparable to whey protein and improved compared to milk protein. The benefits seen with soy or whey protein were independent of changes in muscle mass or fiber cross-sectional area.

  12. Effects of protein-calorie restriction on mechanical function of hypertrophied cardiac muscle

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Cicogna

    1999-04-01

    Full Text Available OBJECTIVE: To assess the effect of food restriction (FR on hypertrophied cardiac muscle in spontaneously hypertensive rats (SHR. METHODS: Isolated papillary muscle preparations of the left ventricle (LV of 60-day-old SHR and of normotensive Wistar-Kyoto (WKY rats were studied. The rats were fed either an unrestricted diet or FR diet (50% of the intake of the control diet for 30 days. The mechanical function of the muscles was evaluated through monitoring isometric and isotonic contractions. RESULTS: FR caused: 1 reduction in the body weight and LV weight of SHR and WKY rats; 2 increase in the time to peak shortening and the time to peak developed tension (DT in the hypertrophied myocardium of the SHR; 3 diverging changes in the mechanical function of the normal cardiac muscles of WKY rats with reduction in maximum velocity of isotonic shortening and of the time for DT to decrease 50% of its maximum value, and increase of the resting tension and of the rate of tension decline. CONCLUSION: Short-term FR causes prolongation of the contraction time of hypertrophied muscles and paradoxal changes in mechanical performance of normal cardiac fibers, with worsening of the shortening indices and of the resting tension, and improvement of the isometric relaxation.

  13. A review: Functional near infrared spectroscopy evaluation in muscle tissues using Monte Carlo simulation

    Science.gov (United States)

    Halim, A. A. A.; Laili, M. H.; Salikin, M. S.; Rusop, M.

    2018-05-01

    Monte Carlo Simulation has advanced their quantification based on number of the photon counting to solve the propagation of light inside the tissues including the absorption, scattering coefficient and act as preliminary study for functional near infrared application. The goal of this paper is to identify the optical properties using Monte Carlo simulation for non-invasive functional near infrared spectroscopy (fNIRS) evaluation of penetration depth in human muscle. This paper will describe the NIRS principle and the basis for its proposed used in Monte Carlo simulation which focused on several important parameters include ATP, ADP and relate with blow flow and oxygen content at certain exercise intensity. This will cover the advantages and limitation of such application upon this simulation. This result may help us to prove that our human muscle is transparent to this near infrared region and could deliver a lot of information regarding to the oxygenation level in human muscle. Thus, this might be useful for non-invasive technique for detecting oxygen status in muscle from living people either athletes or working people and allowing a lots of investigation muscle physiology in future.

  14. Immunological studies on the structure and function of the nicotinic acetylcholine receptor in mammalian muscle

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Y.

    1989-01-01

    The specificity of the antibodies in the serum of a patient with myasthenia gravis for a the {alpha}-bungarotoxin binding sites of the acetylcholine receptor (AChR) was examined using AChRs in the C2 mouse muscle cell line as a model. The antibodies were shown to be specific for one of the two toxin-binding sites. The effect of the antibodies in this myasthenic serum on the functional response of the receptor to cholinergic agonists was also examined using carbamylcholine-induced {sup 22}Na uptake into C2 myotubes as a measured of the receptor function. Antibodies specific for the {gamma}, {delta}, and {epsilon} subunit, respectively, of mammalian muscle AChRs were developed using subunit-specific synthetic peptides as antigens. Using these antibodies and monoclonal antibodies for other subunits as probes, I have identified four ({alpha}, {beta}, {gamma}, and {delta}) subunits of mammalian muscle AChRs on immunoblots. When AChRs from embryonic, neonatal, normal and denervated adult muscles were compared on immunoblots, the {alpha}, {beta}, and {delta} subunits were identical in all four receptor preparations, with or without endoglycosidase digestion. The spatial and temporal distribution of the {gamma}- and {epsilon}- AChRs in developing and in denervated muscles corresponds to the distribution of AChRs with slow and fast channels, respectively, and that the development changes in the channel properties of the receptor arise from a change in the subunit composition of the receptor, in which the {gamma} is replaced by {epsilon}.

  15. Immunological studies on the structure and function of the nicotinic acetylcholine receptor in mammalian muscle

    International Nuclear Information System (INIS)

    Gu, Y.

    1989-01-01

    The specificity of the antibodies in the serum of a patient with myasthenia gravis for a the α-bungarotoxin binding sites of the acetylcholine receptor (AChR) was examined using AChRs in the C2 mouse muscle cell line as a model. The antibodies were shown to be specific for one of the two toxin-binding sites. The effect of the antibodies in this myasthenic serum on the functional response of the receptor to cholinergic agonists was also examined using carbamylcholine-induced 22 Na uptake into C2 myotubes as a measured of the receptor function. Antibodies specific for the γ, δ, and ε subunit, respectively, of mammalian muscle AChRs were developed using subunit-specific synthetic peptides as antigens. Using these antibodies and monoclonal antibodies for other subunits as probes, I have identified four (α, β, γ, and δ) subunits of mammalian muscle AChRs on immunoblots. When AChRs from embryonic, neonatal, normal and denervated adult muscles were compared on immunoblots, the α, β, and δ subunits were identical in all four receptor preparations, with or without endoglycosidase digestion. The spatial and temporal distribution of the γ- and ε- AChRs in developing and in denervated muscles corresponds to the distribution of AChRs with slow and fast channels, respectively, and that the development changes in the channel properties of the receptor arise from a change in the subunit composition of the receptor, in which the γ is replaced by ε

  16. Anatomy, function, and evolution of jaw and hyobranchial muscles in cryptobranchoid salamander larvae.

    Science.gov (United States)

    Kleinteich, Thomas; Herzen, Julia; Beckmann, Felix; Matsui, Masafumi; Haas, Alexander

    2014-02-01

    Larval salamanders (Lissamphibia: Caudata) are known to be effective suction feeders in their aquatic environments, although they will eventually transform into terrestrial tongue feeding adults during metamorphosis. Early tetrapods may have had a similar biphasic life cycle and this makes larval salamanders a particularly interesting model to study the anatomy, function, development, and evolution of the feeding apparatus in terrestrial vertebrates. Here, we provide a description of the muscles that are involved in the feeding strike in salamander larvae of the Hynobiidae and compare them to larvae of the paedomorphic Cryptobranchidae. We provide a functional and evolutionary interpretation for the observed muscle characters. The cranial muscles in larvae from species of the Hynobiidae and Cryptobranchidae are generally very similar. Most notable are the differences in the presence of the m. hyomandibularis, a muscle that connects the hyobranchial apparatus with the lower jaw. We found this muscle only in Onychodactylus japonicus (Hynobiidae) but not in other hynobiid or cryptobranchid salamanders. Interestingly, the m. hyomandibularis in O. japonicus originates from the ceratobranchial I and not the ceratohyal, and thus exhibits what was previously assumed to be the derived condition. Finally, we applied a biomechanical model to simulate suction feeding in larval salamanders. We provide evidence that a flattened shape of the hyobranchial apparatus in its resting position is beneficial for a fast and successful suction feeding strike. Copyright © 2013 Wiley Periodicals, Inc.

  17. Effects of experimental muscle pain on muscle activity and co-ordination during static and dynamic motor function.

    Science.gov (United States)

    Graven-Nielsen, T; Svensson, P; Arendt-Nielsen, L

    1997-04-01

    The relation between muscle pain, muscle activity, and muscle co-ordination is still controversial. The present human study investigates the influence of experimental muscle pain on resting, static, and dynamic muscle activity. In the resting and static experiments, the electromyography (EMG) activity and the contraction force of m. tibialis anterior were assessed before and after injection of 0.5 ml hypertonic saline (5%) into the same muscle. In the dynamic experiment, injections of 0.5 ml hypertonic saline (5%) were performed into either m. tibialis anterior (TA) or m. gastrocnemius (GA) and the muscle activity and co-ordination were investigated during gait on a treadmill by EMG recordings from m. TA and m. GA. At rest no evidence of EMG hyperactivity was found during muscle pain. The maximal voluntary contraction (MVC) during muscle pain was significantly lower than the control condition (P Fibromyalgia and Myofascial Pain. Elsevier, Amsterdam, 1993, pp. 311-327.) which predicts increased activity of antagonistic muscle and decreased activity of agonistic muscle during experimental and clinical muscle pain.

  18. Utility and reliability of non-invasive muscle function tests in high-fat-fed mice.

    Science.gov (United States)

    Martinez-Huenchullan, Sergio F; McLennan, Susan V; Ban, Linda A; Morsch, Marco; Twigg, Stephen M; Tam, Charmaine S

    2017-07-01

    What is the central question of this study? Non-invasive muscle function tests have not been validated for use in the study of muscle performance in high-fat-fed mice. What is the main finding and its importance? This study shows that grip strength, hang wire and four-limb hanging tests are able to discriminate the muscle performance between chow-fed and high-fat-fed mice at different time points, with grip strength being reliable after 5, 10 and 20 weeks of dietary intervention. Non-invasive tests are commonly used for assessing muscle function in animal models. The value of these tests in obesity, a condition where muscle strength is reduced, is unclear. We investigated the utility of three non-invasive muscle function tests, namely grip strength (GS), hang wire (HW) and four-limb hanging (FLH), in C57BL/6 mice fed chow (chow group, n = 48) or a high-fat diet (HFD group, n = 48) for 20 weeks. Muscle function tests were performed at 5, 10 and 20 weeks. After 10 and 20 weeks, HFD mice had significantly reduced GS (in newtons; mean ± SD: 10 weeks chow, 1.89 ± 0.1 and HFD, 1.79 ± 0.1; 20 weeks chow, 1.99 ± 0.1 and HFD, 1.75 ± 0.1), FLH [in seconds per gram body weight; median (interquartile range): 10 weeks chow, 2552 (1337-4964) and HFD, 1230 (749-1994); 20 weeks chow, 2048 (765-3864) and HFD, 1036 (717-1855)] and HW reaches [n; median (interquartile range): 10 weeks chow, 4 (2-5) and HFD, 2 (1-3); 20 weeks chow, 3 (1-5) and HFD, 1 (0-2)] and higher falls [n; median (interquartile range): 10 weeks chow, 0 (0-2) and HFD, 3 (1-7); 20 weeks chow, 1 (0-4) and HFD, 8 (5-10)]. Grip strength was reliable in both dietary groups [intraclass correlation coefficient (ICC) = 0.5-0.8; P tests are valuable and reliable tools for assessment of muscle strength and function in high-fat-fed mice. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

  19. A study of the masticatory muscles morphology and function on asymmetric prognathism

    International Nuclear Information System (INIS)

    Kondoh, Hirotoshi

    1991-01-01

    Each case was measured to analyze the cross sectional area of muscle and mandibular malposition amount using Computed Tomography (CT) photos and P-A cephalogram. At the same time, the relation of morphology and function between the cross sectional area of muscle and mandibular malposition amount was analyzed to examine the function of masseter using electromyography. To determine the relation between morphology and function of masseter in asymmetric prognathism, 23 cases were chosen for the study from among 11 male and 12 female patients who were diagnosed as asymmetric prognathism. In asymmetric prognathism, both morphology and function in the mandibular malposition side were recognized to be larger than that in the cross sectional area of muscle side, on the examination of the cross sectional area of muscle and the activity of masseter. A highly significant and positive correlation was recognized in the left and right difference between the masseteric and medial pterygoid section areas and the CT mandibular malposition amount which were examined by the CT photos. In the left and right difference between the masseteric and medial pterygoid section areas and in the left and right difference of the activity of masseter, there was also a highly positive and significant correlation. (author) 58 refs

  20. ASSESSMENT OF IN VIVO MECHANICAL MUSCLE FUNCTION IN PATIENTS WITH OSTEOARTHRITIS (OA) OF THE HIP; RELIABILITY

    DEFF Research Database (Denmark)

    Jensen, Carsten; Overgaard, Søren; Aagaard, Per

    2009-01-01

    INTRODUCTION Muscle function in patients with hip OA is not well-studied. We established a new setup of tests in order to monitor patients before and after surgery with total hip arthroplasty (THA). A test-retest protocol was designed to evaluate the reproducibility of single- and multi-joint str...

  1. Effects of ageing on single muscle fibre contractile function following short-term immobilisation

    DEFF Research Database (Denmark)

    Hvid, Lars G; Ørtenblad, Niels; Aagaard, Per

    2011-01-01

    Very little attention has been given to the combined effect of healthy ageing and short-term disuse on the contractile function of human single muscle fibres. Therefore, the present study investigated the effects of 2 weeks of lower limb cast immobilisation (i.e. disuse) on selected contractile...

  2. An investigation into the bilateral functional differences of the lower limb muscles in standing and walking

    Directory of Open Access Journals (Sweden)

    Shengyun Liang

    2016-08-01

    Full Text Available To date, most studies use surface electromyographic (sEMG signals as the control source on active rehabilitation robots, and unilateral data are collected based on the gait symmetry hypothesis, which has caused much controversy. The purpose of this study is to quantitatively evaluate the sEMG activity asymmetry of bilateral muscles in lower extremities during functional tasks. Nine participants were instructed to perform static and dynamic steady state tests. sEMG signals from the tibialis anterior, soleus, medial gastrocnemius and lateral gastrocnemius muscles of bilateral lower extremities were recorded in the experiments. Muscle activities are quantified in terms of sEMG amplitude. We investigated whether characteristics of left limb and the one of the right limb have the same statistical characteristics during functional tasks using The Wilcoxon rank-sum test, and studied dynamic signal irregularity degree for sEMG activities via sample entropy. The total of muscle activities showed significant differences between left limb and right limb during the static steady state (p = 0.000. For dynamic steady states, there were significant differences for most muscle activities between left limb and right limb at different speeds (p = 0.000. Nevertheless, there was no difference between the lateral gastrocnemius for bilateral limb at 2.0 kilometers per hour (p = 0.060. For medial gastrocnemius, differences were not found between left limb and right limb at 1.0 and 3.0 kilometers per hours (p = 0.390 and p = 0.085, respectively. Similarly, there was no difference for soleus at 3.0 kilometers per hour (p = 0.115. The importance of the differences in muscle activities between left limb and right limb were found. These results can potentially be used for evaluating lower limb extremity function of special populations (elderly people or stroke patients in an objective and simple method.

  3. Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling.

    Science.gov (United States)

    Miller, Eileen; Czopek, Alicja; Duthie, Karolina M; Kirkby, Nicholas S; van de Putte, Elisabeth E Fransen; Christen, Sibylle; Kimmitt, Robert A; Moorhouse, Rebecca; Castellan, Raphael F P; Kotelevtsev, Yuri V; Kuc, Rhoda E; Davenport, Anthony P; Dhaun, Neeraj; Webb, David J; Hadoke, Patrick W F

    2017-02-01

    The role of smooth muscle endothelin B (ET B ) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ET B receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ET B receptors were selectively deleted from smooth muscle by crossing floxed ET B mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ET B deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ET B was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ET B -mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ET B -mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ET B knockout compared with controls (+4.2±0.2 mm Hg; P<0.0001), but salt-induced and ET B blockade-mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ET B -mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ET B knockout mice. In the absence of other pathology, ET B receptors in vascular smooth muscle make a small but significant contribution to ET B -dependent regulation of BP. These ET B receptors have no effect on vascular contraction or neointimal remodeling. © 2016 The Authors.

  4. Vitamin D Status and Muscle Function Among Adolescent and Young Swimmers

    DEFF Research Database (Denmark)

    Geiker, Nina Rica Wium; Larsen, Rikke; Hansen, Mette

    2017-01-01

    Impaired muscle function has been coupled to vitamin D insufficiency in young women and in elderly men and women. Those living at Northern latitudes are at risk of vitamin D insufficiency due to low sun exposure which may be more pronounced among elite swimmers because of their indoor training...... schedules. We aimed to examine vitamin D status among young elite swimmers and evaluate the association between vitamin D status and muscle strength. Twenty-nine swimmers, 12 female and 17 male (16-24 years) residing at latitude 55-56°N were studied in March and April. Blood samples were analysed for serum...

  5. The role of PGC-1alpha on mitochondrial function and apoptotic susceptibility in muscle

    DEFF Research Database (Denmark)

    Adhihetty, Peter J; Uguccioni, Giulia; Leick, Lotte

    2009-01-01

    Mitochondria are critical for cellular bioenergetics, and they mediate apoptosis within cells. We used whole body peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) knockout (KO) animals to investigate its role on organelle function, apoptotic signaling, and cytochrome......-c oxidase activity, an indicator of mitochondrial content, in muscle and other tissues (brain, liver, and pancreas). Lack of PGC-1alpha reduced mitochondrial content in all muscles (17-44%; P liver, and pancreas. However, the tissue expression of proteins involved...

  6. Inefficient functional sympatholysis is an overlooked cause of malperfusion in contracting skeletal muscle

    DEFF Research Database (Denmark)

    Saltin, Bengt; Mortensen, Stefan P

    2012-01-01

    Contracting skeletal muscle can overcome sympathetic vasoconstrictor activity (functional sympatholysis), which allows for a blood supply that matches the metabolic demand. This ability is thought to be mediated by locally released substances that modulate the effect of noradrenaline (NA) on the α...... sympatholysis and muscle blood flow are impaired compared to young men, but regular physical activity can prevent these age related impairments. In young subjects, two weeks of leg immobilization causes a reduced ability for functional sympatholysis, whereas the trained leg maintained this function. Patients...... with essential hypertension have impaired functional sympatholysis in the forearm, and reduced exercise hyperaemia in the leg, but this can be normalized by aerobic exercise training. The effect of physical activity on the local mechanisms that modulate sympathetic vasoconstriction is clear, but it remains...

  7. Functional Capacity in Adults With Cerebral Palsy: Lower Limb Muscle Strength Matters.

    Science.gov (United States)

    Gillett, Jarred G; Lichtwark, Glen A; Boyd, Roslyn N; Barber, Lee A

    2018-05-01

    To investigate the relation between lower limb muscle strength, passive muscle properties, and functional capacity outcomes in adults with cerebral palsy (CP). Cross-sectional study. Tertiary institution biomechanics laboratory. Adults with spastic-type CP (N=33; mean age, 25y; range, 15-51y; mean body mass, 70.15±21.35kg) who were either Gross Motor Function Classification System (GMFCS) level I (n=20) or level II (n=13). Not applicable. Six-minute walk test (6MWT) distance (m), lateral step-up (LSU) test performance (total repetitions), timed up-stairs (TUS) performance (s), maximum voluntary isometric strength of plantar flexors (PF) and dorsiflexors (DF) (Nm.kg -1 ), and passive ankle joint and muscle stiffness. Maximum isometric PF strength independently explained 61% of variance in 6MWT performance, 57% of variance in LSU test performance, and 50% of variance in TUS test performance. GMFCS level was significantly and independently related to all 3 functional capacity outcomes, and age was retained as a significant independent predictor of LSU and TUS test performance. Passive medial gastrocnemius muscle fascicle stiffness and ankle joint stiffness were not significantly related to functional capacity measures in any of the multiple regression models. Low isometric PF strength was the most important independent variable related to distance walked on the 6MWT, fewer repetitions on the LSU test, and slower TUS test performance. These findings suggest lower isometric muscle strength contributes to the decline in functional capacity in adults with CP. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  8. Functional Echomyography: thickness, ecogenicity, contraction and perfusion of the LMN denervated human muscle before and during h-bFES

    Directory of Open Access Journals (Sweden)

    Riccardo Zanato

    2010-03-01

    Full Text Available Permanent denervated muscles were evaluated by ultrasound to monitor changes in morphology, thickness, contraction-relaxation kinetics and perfusion due to the electrical stimulation program of the Rise2-Italy project. In a case of monolateral lesion, morphology and ultrasonographic structure of the denervated muscles changed during the period of stimulation from a pattern typical of complete denervation-induced muscle atrophy to a pattern which might be considered “normal” when detected in an old patient. Thickness improved significantly more in the middle third of the denervated muscle, reaching the same value as the contralateral innervated muscle. Contraction-relaxation kinetics, measured by recording the muscle movements during electrical stimulation, showed an abnormal behavior of the chronically denervated muscle during the relaxation phase, which resulted to be significantly longer than in normal muscle. The long-term denervated muscles analyzed with Echo Doppler showed at rest a low resistance arterial flow that became pulsed during and after electrical stimulation. As expected, the ultra sound measured electrical stimulation-induced hyperemia lasted longer than the stimulation period. The higher than normal energy of the delivered electrical stimuli of the Vienna home-based Functional Electrical Stimulation strategy (h-b FES demonstrate that the explored muscles were still almost completely denervated during the one-year of training. In conclusion, this pilot study confirms the usefulness of Functional Echomyography in the follow-up and the positive effects of h-b FES of denervated muscles.

  9. Effect of physical training on function of chronically painful muscles: A randomized controlled trial

    DEFF Research Database (Denmark)

    Andersen, Lars L; Andersen, Christoffer H; Zebis, Mette K

    2008-01-01

    .01-0.05). While EMG activity of the unaffected deltoid remained unchanged during the maximal contractions, an increase in EMG amplitude (42-86%, Ppower frequency (19%, Ppainful trapezius muscle. Correspondingly, torque increased 18-53% (P...Purpose: Pain and tenderness of the upper trapezius muscle is frequent in several occupational groups. The objective of this study is to investigate the effect of three contrasting interventions on muscle function and pain in women with trapezius myalgia. Methods: A group of employed women (n=42...... and electromyography (EMG) were recorded during maximal shoulder abductions in an isokinetic dynamometer at -60, 60, 0 and 180 degrees (.)s(-1). Further, a submaximal reference contraction with only the load of the arms was performed. Results: Significant changes were observed only in SST. Pain decreased 42-49% (P

  10. Localization and function of ATP-sensitive potassium channels in human skeletal muscle

    DEFF Research Database (Denmark)

    Nielsen, Jens Jung; Kristensen, Michael; Hellsten, Ylva

    2003-01-01

    The present study investigated the localization of ATP-sensitive K+ (KATP) channels in human skeletal muscle and the functional importance of these channels for human muscle K+ distribution at rest and during muscle activity. Membrane fractionation based on the giant vesicle technique...... or the sucrose-gradient technique in combination with Western blotting demonstrated that the KATP channels are mainly located in the sarcolemma. This localization was confirmed by immunohistochemical measurements. With the microdialysis technique, it was demonstrated that local application of the KATP channel...... to in vitro conditions, the present study demonstrated that under in vivo conditions the KATP channels are active at rest and contribute to the accumulation of interstitial K+....

  11. Fast-twitch glycolytic skeletal muscle is predisposed to age-induced impairments in mitochondrial function

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Díaz, Víctor; Soldini, Lavinia

    2013-01-01

    The etiology of mammalian senescence is suggested to involve the progressive impairment of mitochondrial function; however, direct observations of age-induced alterations in actual respiratory chain function are lacking. Accordingly, we assessed mitochondrial function via high-resolution respirom......The etiology of mammalian senescence is suggested to involve the progressive impairment of mitochondrial function; however, direct observations of age-induced alterations in actual respiratory chain function are lacking. Accordingly, we assessed mitochondrial function via high......-resolution respirometry and mitochondrial protein expression in soleus, quadricep, and lateral gastrocnemius skeletal muscles, which represent type 1 slow-twitch oxidative muscle (soleus) and type 2 fast-twitch glycolytic muscle (quadricep and gastrocnemius), respectively, in young (10-12 weeks) and mature (74-76 weeks......) mice. Electron transport through mitochondrial complexes I and III increases with age in quadricep and gastrocnemius, which is not observed in soleus. Mitochondrial coupling efficiency during respiration through complex I also deteriorates with age in gastrocnemius and shows a tendency (p = .085...

  12. Targeting artificial transcription factors to the utrophin A promoter: effects on dystrophic pathology and muscle function.

    Science.gov (United States)

    Lu, Yifan; Tian, Chai; Danialou, Gawiyou; Gilbert, Rénald; Petrof, Basil J; Karpati, George; Nalbantoglu, Josephine

    2008-12-12

    Duchenne muscular dystrophy is caused by a genetic defect in the dystrophin gene. The absence of dystrophin results in muscle fiber necrosis and regeneration, leading to progressive muscle fiber loss. Utrophin is a close analogue of dystrophin. A substantial, ectopic expression of utrophin in the extrasynaptic sarcolemma of dystrophin-deficient muscle fibers can prevent deleterious effects of dystrophin deficiency. An alternative approach for the extrasynaptic up-regulation of utrophin involves the augmentation of utrophin transcription via the endogenous utrophin A promoter using custom-designed transcriptional activator proteins with zinc finger (ZFP) motifs. We tested a panel of custom-designed ZFP for their ability to activate the utrophin A promoter. Expression of one such ZFP efficiently increased, in a time-dependent manner, utrophin transcript and protein levels both in vitro and in vivo. In dystrophic mouse (mdx) muscles, administration of adenoviral vectors expressing this ZFP led to significant enhancement of muscle function with decreased necrosis, restoration of the dystrophin-associated proteins, and improved resistance to eccentric contractions. These studies provide evidence that specifically designed ZFPs can act as strong transcriptional activators of the utrophin A promoter. These may thus serve as attractive therapeutic agents for dystrophin deficiency states such as Duchenne muscular dystrophy.

  13. Functional and morphological adaptations to aging in knee extensor muscles of physically active men.

    Science.gov (United States)

    Baroni, Bruno Manfredini; Geremia, Jeam Marcel; Rodrigues, Rodrigo; Borges, Marcelo Krás; Jinha, Azim; Herzog, Walter; Vaz, Marco Aurélio

    2013-10-01

    It is not known if a physically active lifestyle, without systematic training, is sufficient to combat age-related muscle and strength loss. Therefore, the purpose of this study was to evaluate if the maintenance of a physically active lifestyle prevents muscle impairments due to aging. To address this issue, we evaluated 33 healthy men with similar physical activity levels (IPAQ = 2) across a large range of ages. Functional (torque-angle and torque-velocity relations) and morphological (vastus lateralis muscle architecture) properties of the knee extensor muscles were assessed and compared between three age groups: young adults (30 ± 6 y), middle-aged subjects (50 ± 7 y) and elderly subjects (69 ± 5 y). Isometric peak torques were significantly lower (30% to 36%) in elderly group subjects compared with the young adults. Concentric peak torques were significantly lower in the middle aged (18% to 32%) and elderly group (40% to 53%) compared with the young adults. Vastus lateralis thickness and fascicles lengths were significantly smaller in the elderly group subjects (15.8 ± 3.9 mm; 99.1 ± 25.8 mm) compared with the young adults (19.8 ± 3.6 mm; 152.1 ± 42.0 mm). These findings suggest that a physically active lifestyle, without systematic training, is not sufficient to avoid loss of strength and muscle mass with aging.

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

    Science.gov (United States)

    Divet, Alexandra; Huchet-Cadiou, Corinne

    2002-08-01

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

  15. In vivo functional and morphological characterization of bone and striated muscle microcirculation in NSG mice.

    Directory of Open Access Journals (Sweden)

    Haider Mussawy

    Full Text Available Organ-specific microcirculation plays a central role in tumor growth, tumor cell homing, tissue engineering, and wound healing. Mouse models are widely used to study these processes; however, these mouse strains often possess unique microhemodynamic parameters, making it difficult to directly compare experiments. The full functional characterization of bone and striated muscle microcirculatory parameters in non-obese diabetic-severe combined immunodeficiency/y-chain; NOD-Prkds IL2rg (NSG mice has not yet been reported. Here, we established either a dorsal skinfold chamber or femur window in NSG mice (n = 23, allowing direct analysis of microcirculatory parameters in vivo by intravital fluorescence microscopy at 7, 14, 21, and 28 days after chamber preparation. Organ-specific differences were observed. Bone had a significantly lower vessel density but a higher vessel diameter than striated muscle. Bone also showed higher effective vascular permeability than striated muscle. The centerline velocity values were similar in the femur window and dorsal skinfold chamber, with a higher volumetric blood flow in bone. Interestingly, bone and striated muscle showed similar tissue perfusion rates. Knowledge of physiological microhemodynamic values of bone and striated muscle in NSG mice makes it possible to analyze pathophysiological processes at these anatomic sites, such as tumor growth, tumor metastasis, and tumor microcirculation, as well as the response to therapeutic agents.

  16. Sport-specific endurance plank test for evaluation of global core muscle function.

    Science.gov (United States)

    Tong, Tom K; Wu, Shing; Nie, Jinlei

    2014-02-01

    To examine the validity and reliability of a sports-specific endurance plank test for the evaluation of global core muscle function. Repeated-measures study. Laboratory environment. Twenty-eight male and eight female young athletes. Surface electromyography (sEMG) of selected trunk flexors and extensors, and an intervention of pre-fatigue core workout were applied for test validation. Intraclass correlation coefficient (ICC), coefficient of variation (CV), and the measurement bias ratio */÷ ratio limits of agreement (LOA) were calculated to assess reliability and measurement error. Test validity was shown by the sEMG of selected core muscles, which indicated >50% increase in muscle activation during the test; and the definite discrimination of the ∼30% reduction in global core muscle endurance subsequent to a pre-fatigue core workout. For test-retest reliability, when the first attempt of three repeated trials was considered as familiarisation, the ICC was 0.99 (95% CI: 0.98-0.99), CV was 2.0 ± 1.56% and the measurement bias ratio */÷ ratio LOA was 0.99 */÷ 1.07. The findings suggest that the sport-specific endurance plank test is a valid, reliable and practical method for assessing global core muscle endurance in athletes given that at least one familiarisation trial takes place prior to measurement. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. A 1D pulse wave propagation model of the hemodynamics of calf muscle pump function.

    Science.gov (United States)

    Keijsers, J M T; Leguy, C A D; Huberts, W; Narracott, A J; Rittweger, J; van de Vosse, F N

    2015-07-01

    The calf muscle pump is a mechanism which increases venous return and thereby compensates for the fluid shift towards the lower body during standing. During a muscle contraction, the embedded deep veins collapse and venous return increases. In the subsequent relaxation phase, muscle perfusion increases due to increased perfusion pressure, as the proximal venous valves temporarily reduce the distal venous pressure (shielding). The superficial and deep veins are connected via perforators, which contain valves allowing flow in the superficial-to-deep direction. The aim of this study is to investigate and quantify the physiological mechanisms of the calf muscle pump, including the effect of venous valves, hydrostatic pressure, and the superficial venous system. Using a one-dimensional pulse wave propagation model, a muscle contraction is simulated by increasing the extravascular pressure in the deep venous segments. The hemodynamics are studied in three different configurations: a single artery-vein configuration with and without valves and a more detailed configuration including a superficial vein. Proximal venous valves increase effective venous return by 53% by preventing reflux. Furthermore, the proximal valves shielding function increases perfusion following contraction. Finally, the superficial system aids in maintaining the perfusion during the contraction phase and reduces the refilling time by 37%. © 2015 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.

  18. Function and structure of the deep cervical extensor muscles in patients with neck pain.

    Science.gov (United States)

    Schomacher, Jochen; Falla, Deborah

    2013-10-01

    The deep cervical extensors are anatomically able to control segmental movements of the cervical spine in concert with the deep cervical flexors. Several investigations have confirmed changes in cervical flexor muscle control in patients with neck pain and as a result, effective evidence-based therapeutic exercises have been developed to address such dysfunctions. However, knowledge on how the deep extensor muscles behave in patients with neck pain disorders is scare. Structural changes such as higher concentration of fat within the muscle, variable cross-sectional area and higher proportions of type II fibres have been observed in the deep cervical extensors of patients with neck pain compared to healthy controls. These findings suggest that the behaviour of the deep extensors may be altered in patients with neck pain. Consistent with this hypothesis, a recent series of studies confirm that patients display reduced activation of the deep cervical extensors as well as less defined activation patterns. This article provides an overview of the various different structural and functional changes in the deep neck extensor muscles documented in patients with neck pain. Relevant recommendations for the management of muscle dysfunction in patients with neck pain are presented. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Respiratory muscle stretch gymnastics in patients with post coronary artery bypass grafting pain : Impact on respiratory muscle function, activity, mood and exercise capacity

    OpenAIRE

    會田, 信子; 渋谷, 優子; 吉野, 克樹; Komoda, Masaji; 井上, 智子

    2002-01-01

    A new rehabilitation (New-RH) program including respiratory muscle stretch gymnastics (RMSG) was developed to alleviate post-coronary artery bypass grafting pain (PCP). Effects on respiratory muscle function, pain, activities of daily living (ADL), mood and exercise capacity were investigated. Subjects were 16 consecutive patients undergoing median full sternotomy coronary artery bypass grafting (CABG), and were randomly divided into equal New-RH (S-group) and conventional therapy (C-group) g...

  20. Translating golden retriever muscular dystrophy microarray findings to novel biomarkers for cardiac/skeletal muscle function in Duchenne muscular dystrophy.

    Science.gov (United States)

    Galindo, Cristi L; Soslow, Jonathan H; Brinkmeyer-Langford, Candice L; Gupte, Manisha; Smith, Holly M; Sengsayadeth, Seng; Sawyer, Douglas B; Benson, D Woodrow; Kornegay, Joe N; Markham, Larry W

    2016-04-01

    In Duchenne muscular dystrophy (DMD), abnormal cardiac function is typically preceded by a decade of skeletal muscle disease. Molecular reasons for differences in onset and progression of these muscle groups are unknown. Human biomarkers are lacking. We analyzed cardiac and skeletal muscle microarrays from normal and golden retriever muscular dystrophy (GRMD) dogs (ages 6, 12, or 47+ mo) to gain insight into muscle dysfunction and to identify putative DMD biomarkers. These biomarkers were then measured using human DMD blood samples. We identified GRMD candidate genes that might contribute to the disparity between cardiac and skeletal muscle disease, focusing on brain-derived neurotropic factor (BDNF) and osteopontin (OPN/SPP1, hereafter indicated as SPP1). BDNF was elevated in cardiac muscle of younger GRMD but was unaltered in skeletal muscle, while SPP1 was increased only in GRMD skeletal muscle. In human DMD, circulating levels of BDNF were inversely correlated with ventricular function and fibrosis, while SPP1 levels correlated with skeletal muscle function. These results highlight gene expression patterns that could account for differences in cardiac and skeletal disease in GRMD. Most notably, animal model-derived data were translated to DMD and support use of BDNF and SPP1 as biomarkers for cardiac and skeletal muscle involvement, respectively.

  1. NAD+ repletion improves muscle function in muscular dystrophy and counters global PARylation.

    Science.gov (United States)

    Ryu, Dongryeol; Zhang, Hongbo; Ropelle, Eduardo R; Sorrentino, Vincenzo; Mázala, Davi A G; Mouchiroud, Laurent; Marshall, Philip L; Campbell, Matthew D; Ali, Amir Safi; Knowels, Gary M; Bellemin, Stéphanie; Iyer, Shama R; Wang, Xu; Gariani, Karim; Sauve, Anthony A; Cantó, Carles; Conley, Kevin E; Walter, Ludivine; Lovering, Richard M; Chin, Eva R; Jasmin, Bernard J; Marcinek, David J; Menzies, Keir J; Auwerx, Johan

    2016-10-19

    Neuromuscular diseases are often caused by inherited mutations that lead to progressive skeletal muscle weakness and degeneration. In diverse populations of normal healthy mice, we observed correlations between the abundance of mRNA transcripts related to mitochondrial biogenesis, the dystrophin-sarcoglycan complex, and nicotinamide adenine dinucleotide (NAD + ) synthesis, consistent with a potential role for the essential cofactor NAD + in protecting muscle from metabolic and structural degeneration. Furthermore, the skeletal muscle transcriptomes of patients with Duchene's muscular dystrophy (DMD) and other muscle diseases were enriched for various poly[adenosine 5'-diphosphate (ADP)-ribose] polymerases (PARPs) and for nicotinamide N-methyltransferase (NNMT), enzymes that are major consumers of NAD + and are involved in pleiotropic events, including inflammation. In the mdx mouse model of DMD, we observed significant reductions in muscle NAD + levels, concurrent increases in PARP activity, and reduced expression of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme for NAD + biosynthesis. Replenishing NAD + stores with dietary nicotinamide riboside supplementation improved muscle function and heart pathology in mdx and mdx/Utr -/- mice and reversed pathology in Caenorhabditis elegans models of DMD. The effects of NAD + repletion in mdx mice relied on the improvement in mitochondrial function and structural protein expression (α-dystrobrevin and δ-sarcoglycan) and on the reductions in general poly(ADP)-ribosylation, inflammation, and fibrosis. In combination, these studies suggest that the replenishment of NAD + may benefit patients with muscular dystrophies or other neuromuscular degenerative conditions characterized by the PARP/NNMT gene expression signatures. Copyright © 2016, American Association for the Advancement of Science.

  2. Serum levo-carnitine levels and skeletal muscle functions in type 2 diabetes mellitus in rodents

    International Nuclear Information System (INIS)

    Aleem, S.B.; Hussain, M.M.; Farooq, Y.

    2013-01-01

    Objective: To study serum levo-carnitine (l-carnitine) levels and isometric contraction, force frequency relationship and fatigue of rodent skeletal muscles in type 2 diabetes mellitus. Study Design: Randomized controlled trial. Place and Duration of Study: Physiology Department, Army Medical College, Rawalpindi, from January 2009 to January 2010. Methodology: Sixty Sprague-Dawley rats were randomly divided into two groups; group I (control), fed on normal diet ad libitum and Group II (diabetic), fed on high fat diet and administered streptozocin to induce type 2 diabetes mellitus (T2DM). At 21st day, plasma glucose and TG/HDL ratio were measured to confirm the development of T2DM in group II. At 28th day, blood was drawn by intracardiac puncture to estimate serum levo-carnitine levels. Contractile functions of skeletal muscles were assessed by using iWorx AHK/214 physiological data acquisition unit. Simple muscle twitches, maximum isometric twitch tension (MITT), time-to-peak twitch tension (TPTT) and time-to-relax to 50% of the peak twitch tension (1/2RT) of extensor digitorum muscles were recorded. Muscles were stimulated at higher frequencies to determine maximum fused tetanic tension (MFTT), maximum fused tetanic tension after fatigue protocol (TTFP) and recovery from fatigue (RF). Results: Serum levo-carnitine level decreased significantly in the diabetic group. Both groups had similar MITT, TPTT and 1/2RT but decline in MFTT, TTFP and RF was significant in the diabetic rats. Conclusion: T2DM adversely affected serum levo-carnitine levels and the contractile functions of rodent skeletal muscle at high frequency stimulation. (author)

  3. The Structural and Functional Coordination of Glycolytic Enzymes in Muscle: Evidence of a Metabolon?

    Directory of Open Access Journals (Sweden)

    Lynda Menard

    2014-09-01

    Full Text Available Metabolism sustains life through enzyme-catalyzed chemical reactions within the cells of all organisms. The coupling of catalytic function to the structural organization of enzymes contributes to the kinetic optimization important to tissue-specific and whole-body function. This coupling is of paramount importance in the role that muscle plays in the success of Animalia. The structure and function of glycolytic enzyme complexes in anaerobic metabolism have long been regarded as a major regulatory element necessary for muscle activity and whole-body homeostasis. While the details of this complex remain to be elucidated through in vivo studies, this review will touch on recent studies that suggest the existence of such a complex and its structure. A potential model for glycolytic complexes and related subcomplexes is introduced.

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

    Science.gov (United States)

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

    2001-04-01

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

  5. Joint laxity and the relationship between muscle strength and functional ability in patients with osteoarthritis of the knee.

    Science.gov (United States)

    van der Esch, M; Steultjens, M; Knol, D L; Dinant, H; Dekker, J

    2006-12-15

    To establish the impact of knee joint laxity on the relationship between muscle strength and functional ability in osteoarthritis (OA) of the knee. A cross-sectional study of 86 patients with OA of the knee was conducted. Tests were performed to determine varus-valgus laxity, muscle strength, and functional ability. Laxity was assessed using a device that measures the angular deviation of the knee in the frontal plane. Muscle strength was measured using a computer-driven isokinetic dynamometer. Functional ability was assessed by observation (100-meter walking test) and self report (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]). Regression analyses were performed to assess the impact of joint laxity on the relationship between muscle strength and functional ability. In regression analyses, the interaction between muscle strength and joint laxity contributed to the variance in both walking time (P = 0.002) and WOMAC score (P = 0.080). The slope of the regression lines indicated that the relationship between muscle strength and functional ability (walking time, WOMAC) was stronger in patients with high knee joint laxity. Patients with knee OA and high knee joint laxity show a stronger relationship between muscle strength and functional ability than patients with OA and low knee joint laxity. Patients with OA, high knee joint laxity, and low muscle strength are most at risk of being disabled.

  6. Quadriceps muscle function after rehabilitation with cryotherapy in patients with anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Hart, Joseph M; Kuenze, Christopher M; Diduch, David R; Ingersoll, Christopher D

    2014-01-01

    Persistent muscle weakness after anterior cruciate ligament (ACL) reconstruction may be due to underlying activation failure and arthrogenic muscle inhibition (AMI). Knee-joint cryotherapy has been shown to improve quadriceps function transiently in those with AMI, thereby providing an opportunity to improve quadriceps muscle activation and strength in patients with a reconstructed ACL. To compare quadriceps muscle function in patients with a reconstructed ACL who completed a 2-week intervention including daily cryotherapy (ice bag), daily exercises, or both. Cross-sectional study. Laboratory. A total of 30 patients with reconstructed ACLs who were at least 6 months post-index surgery and had measurable quadriceps AMI. The patients attended 4 supervised visits over a 2-week period. They were randomly assigned to receive 20 minutes of knee-joint cryotherapy, 1 hour of therapeutic rehabilitation exercises, or cryotherapy followed by exercises. We measured quadriceps Hoffmann reflex, normalized maximal voluntary isometric contraction torque, central activation ratio using the superimposed-burst technique, and patient-reported outcomes before and after the intervention period. After the 2-week intervention period, patients who performed rehabilitation exercises immediately after cryotherapy had higher normalized maximal voluntary isometric contraction torques (P = .002, Cohen d effect size = 1.4) compared with those who received cryotherapy alone (P = .16, d = 0.58) or performed exercise alone (P = .16, d = 0.30). After ACL reconstruction, patients with AMI who performed rehabilitation exercises immediately after cryotherapy experienced greater strength gains than those who performed cryotherapy or exercises alone.

  7. Reproducibility and clinical utility of tendon palpation to detect patellar tendinopathy in young basketball players. Victorian Institute of Sport tendon study group.

    Science.gov (United States)

    Cook, J L; Khan, K M; Kiss, Z S; Purdam, C R; Griffiths, L

    2001-02-01

    Palpation is an important clinical test for jumper's knee. To (a) test the reproducibility of palpation tenderness, (b) evaluate the sensitivity and specificity of palpation in subjects with clinical symptoms of jumper's knee, and (c) determine whether tenderness to palpation may serve as a useful screening test for patellar tendinopathy. The yardstick for diagnosis of patellar tendinopathy was ultrasonographic abnormality. In 326 junior symptomatic and asymptomatic athletes' tendons, palpation was performed by a single examiner before ultrasonographic examination by a certified ultrasound radiologist. In 58 tendons, palpation was performed twice to test reliability. Tenderness to palpation was scored on a scale from 0 to 3 where 0 represented no pain, and 1, 2, and 3 represented mild, moderate, and severe tenderness respectively. Patellar tendon palpation was a reliable examination for a single examiner (Pearson r = 0.82). In symptomatic tendons, the positive predictive value of palpation was 68%. As a screening examination in asymptomatic subjects, the positive predictive value of tendon palpation was 36-38%. Moderate and severe palpation tenderness were better predictors of ultrasonographic tendon pathology than absent or mild tenderness (ppatellar tendinopathy in a preparticipation examination. In symptomatic tendons, palpation is a moderately sensitive but not specific test. Mild tenderness in the patellar tendons in asymptomatic jumping athletes should be considered normal.

  8. Analysis of isokinetic muscle function and postural control in individuals with intermittent claudication

    Directory of Open Access Journals (Sweden)

    Morgan Lanzarin

    2016-02-01

    Full Text Available BACKGROUND: Intermittent claudication (IC is a debilitating condition that mostly affects elderly people. IC is manifested by a decrease in ambulatory function. Individuals with IC present with motor and sensory nerve dysfunction in the lower extremities, which may lead to deficits in balance. OBJECTIVE: This study aimed to measure postural control and isokinetic muscle function in individuals with intermittent claudication. METHOD: The study included 32 participants of both genders, 16 IC participants (mean age: 64 years, SD=6 and 16 healthy controls (mean age: 67 years, SD=5, which were allocated into two groups: intermittent claudication group (ICG and control group (CG. Postural control was assessed using the displacement and velocity of the center of pressure (COP during the sensory organization test (SOT and the motor control test (MCT. Muscle function of the flexor and extensor muscles of the knee and ankle was measured by an isokinetic dynamometer. Independent t tests were used to calculate the between-group differences. RESULTS: The ICG presented greater displacement (p =0.027 and speed (p =0.033 of the COP in the anteroposterior direction (COPap during the MCT, as well as longer latency (p =0.004. There were no between-group differences during the SOT. The ICG showed decreased muscle strength and power in the plantar flexors compared to the CG. CONCLUSION: Subjects with IC have lower values of strength and muscle power of plantiflexores, as well as changes in postural control in dynamic conditions. These individuals may be more vulnerable to falls than healthy subjects.

  9. Impaired skeletal muscle mitochondrial function in morbidly obese patients is normalized one year after bariatric surgery.

    Science.gov (United States)

    Vijgen, Guy H E J; Bouvy, Nicole D; Hoeks, Joris; Wijers, Sander; Schrauwen, Patrick; van Marken Lichtenbelt, Wouter D

    2013-01-01

    Obesity and type 2 diabetes are associated with impaired skeletal muscle mitochondrial metabolism. As an intrinsic characteristic of an individual, skeletal muscle mitochondrial dysfunction could be a risk factor for weight gain and obesity-associated co-morbidities, such as type 2 diabetes. On the other hand, impaired skeletal muscle metabolism could be a consequence of obesity. We hypothesize that marked weight loss after bariatric surgery recovers skeletal muscle mitochondrial function. Skeletal muscle mitochondrial function as assessed by high-resolution respirometry was measured in 8 morbidly obese patients (body mass index [BMI], 41.3±4.7 kg/m(2); body fat, 48.3%±5.2%) before and 1 year after bariatric surgery (mean weight loss: 35.0±8.6 kg). The results were compared with a lean (BMI 22.8±1.1 kg/m(2); body fat, 15.6%±4.7%) and obese (BMI 33.5±4.2 kg/m(2); body fat, 34.1%±6.3%) control group. Before surgery, adenosine diphosphate (ADP)-stimulated (state 3) respiration on glutamate/succinate was decreased compared with lean patients (9.5±2.4 versus 15.6±4.4 O2 flux/mtDNA; Psurgery, mitochondrial function was comparable to that of lean controls (after weight loss, 12.3±5.5; lean, 15.6±4.4 O2 flux/mtDNA). In addition, we observed an increased state 3 respiration on a lipid substrate after weight loss (10.0±3.2 versus 14.0±6.6 O2 flux/mtDNA; Pweight loss. Copyright © 2013 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  10. Lumbar muscle structure and function in chronic versus recurrent low back pain: a cross-sectional study.

    Science.gov (United States)

    Goubert, Dorien; De Pauw, Robby; Meeus, Mira; Willems, Tine; Cagnie, Barbara; Schouppe, Stijn; Van Oosterwijck, Jessica; Dhondt, Evy; Danneels, Lieven

    2017-09-01

    Heterogeneity exists within the low back pain (LBP) population. Some patients recover after every pain episode, whereas others suffer daily from LBP complaints. Until now, studies rarely make a distinction between recurrent low back pain (RLBP) and chronic low back pain (CLBP), although both are characterized by a different clinical picture. Clinical experiences also indicate that heterogeneity exists within the CLBP population. Muscle degeneration, like atrophy, fat infiltration, alterations in muscle fiber type, and altered muscle activity, compromises proper biomechanics and motion of the spinal units in LBP patients. The amount of alterations in muscle structure and muscle function of the paraspinal muscles might be related to the recurrence or chronicity of LBP. The aim of this experimental study is to evaluate differences in muscle structure (cross-sectional area and lean muscle fat index) and muscle activity of the multifidus (MF) and erector spinae (ES) during trunk extension, in patients with RLBP, non-continuous CLBP, and continuous CLBP. This cross-sectional study took place in the university hospital of Ghent, Belgium. Muscle structure characteristics and muscle activity were assessed by magnetic resonance imaging (MRI). Fifty-five adults with non-specific LBP (24 RLBP in remission, 15 non-continuous CLBP, 16 continuous CLBP) participated in this study. Total cross-sectional area, muscle cross-sectional area, fat cross-sectional area, lean muscle fat index, T2-rest and T2-shift were assessed. A T1-weighted Dixon MRI scan was used to evaluate spinal muscle cross-sectional area and fat infiltration in the lumbar MF and ES. Muscle functional MRI was used to evaluate the muscle activity of the lumbar MF and ES during a lumbar extension exercise. Before and after the exercise, a pain assessment was performed. This study was supported by grants from the Special Research Fund of Ghent University (DEF12/AOP/022) without potential conflict of interest

  11. Regulation and dysregulation of esophageal peristalsis by the integrated function of circular and longitudinal muscle layers in health and disease.

    Science.gov (United States)

    Mittal, Ravinder K

    2016-09-01

    Muscularis propria throughout the entire gastrointestinal tract including the esophagus is comprised of circular and longitudinal muscle layers. Based on the studies conducted in the colon and the small intestine, for more than a century, it has been debated whether the two muscle layers contract synchronously or reciprocally during the ascending contraction and descending relaxation of the peristaltic reflex. Recent studies in the esophagus and colon prove that the two muscle layers indeed contract and relax together in almost perfect synchrony during ascending contraction and descending relaxation of the peristaltic reflex, respectively. Studies in patients with various types of esophageal motor disorders reveal temporal disassociation between the circular and longitudinal muscle layers. We suggest that the discoordination between the two muscle layers plays a role in the genesis of esophageal symptoms, i.e., dysphagia and esophageal pain. Certain pathologies may selectively target one and not the other muscle layer, e.g., in eosinophilic esophagitis there is a selective dysfunction of the longitudinal muscle layer. In achalasia esophagus, swallows are accompanied by the strong contraction of the longitudinal muscle without circular muscle contraction. The possibility that the discoordination between two muscle layers plays a role in the genesis of esophageal symptoms, i.e., dysphagia and esophageal pain are discussed. The purpose of this review is to summarize the regulation and dysregulation of peristalsis by the coordinated and discoordinated function of circular and longitudinal muscle layers in health and diseased states.

  12. Muscle function recovery in golden retriever muscular dystrophy after AAV1-U7 exon skipping.

    Science.gov (United States)

    Vulin, Adeline; Barthélémy, Inès; Goyenvalle, Aurélie; Thibaud, Jean-Laurent; Beley, Cyriaque; Griffith, Graziella; Benchaouir, Rachid; le Hir, Maëva; Unterfinger, Yves; Lorain, Stéphanie; Dreyfus, Patrick; Voit, Thomas; Carlier, Pierre; Blot, Stéphane; Garcia, Luis

    2012-11-01

    Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder resulting from lesions of the gene encoding dystrophin. These usually consist of large genomic deletions, the extents of which are not correlated with the severity of the phenotype. Out-of-frame deletions give rise to dystrophin deficiency and severe DMD phenotypes, while internal deletions that produce in-frame mRNAs encoding truncated proteins can lead to a milder myopathy known as Becker muscular dystrophy (BMD). Widespread restoration of dystrophin expression via adeno-associated virus (AAV)-mediated exon skipping has been successfully demonstrated in the mdx mouse model and in cardiac muscle after percutaneous transendocardial delivery in the golden retriever muscular dystrophy dog (GRMD) model. Here, a set of optimized U7snRNAs carrying antisense sequences designed to rescue dystrophin were delivered into GRMD skeletal muscles by AAV1 gene transfer using intramuscular injection or forelimb perfusion. We show sustained correction of the dystrophic phenotype in extended muscle areas and partial recovery of muscle strength. Muscle architecture was improved and fibers displayed the hallmarks of mature and functional units. A 5-year follow-up ruled out immune rejection drawbacks but showed a progressive decline in the number of corrected muscle fibers, likely due to the persistence of a mild dystrophic process such as occurs in BMD phenotypes. Although AAV-mediated exon skipping was shown safe and efficient to rescue a truncated dystrophin, it appears that recurrent treatments would be required to maintain therapeutic benefit ahead of the progression of the disease.

  13. Muscle fatigue in relation to forearm pain and tenderness among professional computer users

    DEFF Research Database (Denmark)

    Thomsen, GF; Johnson, PW; Svendsen, Susanne Wulff

    2007-01-01

    ABSTRACT: BACKGROUND: To examine the hypothesis that forearm pain with palpation tenderness in computer users is associated with increased extensor muscle fatigue. METHODS: Eighteen persons with pain and moderate to severe palpation tenderness in the extensor muscle group of the right forearm...... response was not explained by differences in the MVC or body mass index. CONCLUSION: Computer users with forearm pain and moderate to severe palpation tenderness had diminished forearm extensor muscle fatigue response. Additional studies are necessary to determine whether this result reflects an adaptive...... and twenty gender and age matched referents without such complaints were enrolled from the Danish NUDATA study of neck and upper extremity disorders among technical assistants and machine technicians. Fatigue of the right forearm extensor muscles was assessed by muscle twitch forces in response to low...

  14. Functional Magnetic Stimulation of Inspiratory and Expiratory Muscles in Subjects With Tetraplegia.

    Science.gov (United States)

    Zhang, Xiaoming; Plow, Ela; Ranganthan, Vinoth; Huang, Honglian; Schmitt, Melissa; Nemunaitis, Gregory; Kelly, Clay; Frost, Frederick; Lin, Vernon

    2016-07-01

    Respiratory complications are major causes of morbidity and mortality in persons with a spinal cord injury, partly because of respiratory muscle paralysis. Earlier investigation has demonstrated that functional magnetic stimulation (FMS) can be used as a noninvasive technology for activating expiratory muscles, thus producing useful expiratory functions (simulated cough) in subjects with spinal cord injury. To evaluate the effectiveness of FMS for conditioning inspiratory and expiratory muscles in persons with tetraplegia. A prospective before and after trial. FMS Laboratory, Louis Stokes Cleveland VA Medical Center, Cleveland, OH. Six persons with tetraplegia. Each subject participated in a 6-week FMS protocol for conditioning the inspiratory and expiratory muscles. A magnetic stimulator was used with the center of a magnetic coil placed at the C7-T1 and T9-T10 spinous processes, respectively. Pulmonary function tests were performed before, during, and after the protocol. Respiratory variables included maximal inspiratory pressure (MIP), inspiratory reserve volume (IRV), peak inspiratory flow (PIF), maximal expiratory pressure (MEP), expiratory reserve volume (ERV), and peak expiratory flow (PEF). After 6 weeks of conditioning, the main outcome measurements (mean ± standard error) were as follows: MIP, 89.6 ± 7.3 cm H2O; IRV, 1.90 ± 0.34 L; PIF, 302.4 ± 36.3 L/min; MEP, 67.4 ± 11.1 cm H2O; ERV, 0.40 ± 0.06 L; and PEF, 372.4 ± 31.9 L/min. These values corresponded to 117%, 107%, 136%, 109%, 130%, and 124% of pre-FMS conditioning values, respectively. Significant improvements were observed in MIP (P = .022), PIF (P = .0001), and PEF (P = .0006), respectively. When FMS was discontinued for 4 weeks, these values showed decreases from their values at the end of the conditioning protocol, which suggests that continual FMS may be necessary to maintain improved respiratory functions. FMS conditioning of the inspiratory and expiratory muscles improved

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

    Science.gov (United States)

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

    2016-05-01

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

  16. Three-finger tracheal palpation to guide endotracheal tube depth in children.

    Science.gov (United States)

    Gamble, Jonathan J; McKay, William P; Wang, Andrew F; Yip, Kinsha A; O'Brien, Jennifer M; Plewes, Christopher E

    2014-10-01

    Accurate endotracheal tube (ETT) depth is critical, especially in children. The current tools used to guide appropriate ETT depth have significant limitations. To evaluate the utility of tracheal palpation in the neck to guide appropriate ETT placement in children. A prospective observational study with a convenience sample of 50 children was conducted. During intubation, an investigator palpated the trachea with three fingertips side-by-side extending upward from the suprasternal notch. The anesthesiologist advanced the ETT slowly until palpated at the sternal notch. The investigator stated ETT palpation certainty as 'strongly felt', 'weakly felt', or 'not felt.' Final ETT position was determined by bronchoscopy and categorized as 'ETT too shallow' (tip in proximal ¼ of trachea), 'ETT too deep' (tip in distal ¼ of trachea), or 'ETT placement satisfactory' (between those extremes). Thirty boys and 20 girls undergoing dental surgery with nasal intubation were recruited (median age 4.4 years; range 2.0-10.8). The ETT (all ≥4 mm ID) was palpable at the sternal notch in all patients: 46 of 50 strongly palpable and 4 of 50 weakly palpable. The experimental methods led to satisfactory ETT placement in 49 of 50 patients, too deep in 1 of 50 patients. Compared with the Pediatrics Advanced Life Support (PALS) predictive formula, satisfactory placement would have been 41 of 50 patients (P guide ETT placement has excellent clinical performance and better guides appropriate ETT depth than the PALS formula in our study population. © 2014 John Wiley & Sons Ltd.

  17. Modulation of jaw muscle spindle afferent activity following intramuscular injections with hypertonic saline.

    Science.gov (United States)

    Ro, J Y; Capra, N F

    2001-05-01

    Transient noxious chemical stimulation of small diameter muscle afferents modulates jaw movement-related responses of caudal brainstem neurons. While it is likely that the effect is mediated from the spindle afferents in the mesencephalic nucleus (Vmes) via the caudally projecting Probst's tract, the mechanisms of pain induced modulations of jaw muscle spindle afferents is not known. In the present study, we tested the hypothesis that jaw muscle nociceptors gain access to muscle spindle afferents in the same muscle via central mechanisms and alter their sensitivity. Thirty-five neurons recorded from the Vmes were characterized as muscle spindle afferents based on their responses to passive jaw movements, muscle palpation, and electrical stimulation of the masseter nerve. Each cell was tested by injecting a small volume (250 microl) of either 5% hypertonic and/or isotonic saline into the receptor-bearing muscle. Twenty-nine units were tested with 5% hypertonic saline, of which 79% (23/29) showed significant modulation of mean firing rates (MFRs) during one or more phases of ramp-and-hold movements. Among the muscle spindle primary-like units (n = 12), MFRs of 4 units were facilitated, five reduced, two showed mixed responses and one unchanged. In secondary-like units (n = 17), MFRs of 9 were facilitated, three reduced and five unchanged. Thirteen units were tested with isotonic saline, of which 77% showed no significant changes of MFRs. Further analysis revealed that the hypertonic saline not only affected the overall output of muscle spindle afferents, but also increased the variability of firing and altered the relationship between afferent signal and muscle length. These results demonstrated that activation of muscle nociceptors significantly affects proprioceptive properties of jaw muscle spindles via central neural mechanisms. The changes can have deleterious effects on oral motor function as well as kinesthetic sensibility.

  18. Experimental muscle pain produces central modulation of proprioceptive signals arising from jaw muscle spindles.

    Science.gov (United States)

    Capra, N F; Ro, J Y

    2000-05-01

    The aim of the present study was to investigate the effects of intramuscular injection with hypertonic saline, a well-established experimental model for muscle pain, on central processing of proprioceptive input from jaw muscle spindle afferents. Fifty-seven cells were recorded from the medial edge of the subnucleus interpolaris (Vi) and the adjacent parvicellular reticular formation from 11 adult cats. These cells were characterized as central units receiving jaw muscle spindle input based on their responses to electrical stimulation of the masseter nerve, muscle palpation and jaw stretch. Forty-five cells, which were successfully tested with 5% hypertonic saline, were categorized as either dynamic-static (DS) (n=25) or static (S) (n=20) neurons based on their responses to different speeds and amplitudes of jaw movement. Seventy-six percent of the cells tested with an ipsilateral injection of hypertonic saline showed a significant modulation of mean firing rates (MFRs) during opening and/or holding phases. The most remarkable saline-induced change was a significant reduction of MFR during the hold phase in S units (100%, 18/18 modulated). Sixty-nine percent of the DS units (11/16 modulated) also showed significant changes in MFRs limited to the hold phase. However, in the DS neurons, the MFRs increased in seven units and decreased in four units. Finally, five DS neurons showed significant changes of MFRs during both opening and holding phases. Injections of isotonic saline into the ipsilateral masseter muscle had little effect, but hypertonic saline injections made into the contralateral masseter muscle produced similar results to ipsilateral injections with hypertonic saline. These results unequivocally demonstrate that intramuscular injection with an algesic substance, sufficient to produce muscle pain, produces significant changes in the proprioceptive properties of the jaw movement-related neurons. Potential mechanisms involved in saline-induced changes in the

  19. Inefficient skeletal muscle oxidative function flanks impaired motor neuron recruitment in Amyotrophic Lateral Sclerosis during exercise.

    Science.gov (United States)

    Lanfranconi, F; Ferri, A; Corna, G; Bonazzi, R; Lunetta, C; Silani, V; Riva, N; Rigamonti, A; Maggiani, A; Ferrarese, C; Tremolizzo, L

    2017-06-07

    This study aimed to evaluate muscle oxidative function during exercise in amyotrophic lateral sclerosis patients (pALS) with non-invasive methods in order to assess if determinants of reduced exercise tolerance might match ALS clinical heterogeneity. 17 pALS, who were followed for 4 months, were compared with 13 healthy controls (CTRL). Exercise tolerance was assessed by an incremental exercise test on cycle ergometer measuring peak O 2 uptake ([Formula: see text]O 2peak ), vastus lateralis oxidative function by near infrared spectroscopy (NIRS) and breathing pattern ([Formula: see text]E peak ). pALS displayed: (1) 44% lower [Formula: see text]O 2peak vs. CTRL (p motor units recruitment, is a major determinant of pALS clinical heterogeneity and working capacity exercise tolerance. CPET and NIRS are useful tools for detecting early stages of oxidative deficiency in skeletal muscles, disclosing individual impairments in the O 2 transport and utilization chain.

  20. Muscle function is associated with future patient-reported outcomes in young adults with ACL injury

    DEFF Research Database (Denmark)

    Flosadottir, Vala; Roos, Ewa M; Ageberg, Eva

    2016-01-01

    performance and worse postural orientation were associated with worse KOOS scores 2 years later (rsp≥0.280, p≤0.045). Worse muscle power was associated with lower future ARS scores (rsp=0.281, p=0.044). CONCLUSIONS: The moderate associations suggest that improving muscle function during rehabilitation could...... and postural orientation 3 years (SD 0.85) after ACL injury. PROs at 3 and 5 years after injury included Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales Function in sport and recreation (KOOS Sport/rec) and Knee-related Quality of life (KOOS QoL), KOOS item Q3 (KOOS Q3), Tegner Activity Scale...... improve present and future PROs....

  1. Comparative data from young men and women on masseter muscle fibres, function and facial morphology

    DEFF Research Database (Denmark)

    Tuxen, A.; Bakke, M.; Pinholt, E. M.

    1999-01-01

    The primary aim was to relate information about masseter muscle fibres and function to aspects of facial morphology in a group of healthy young men. The secondary aim was to investigate possible sex differences using data previously obtained from a comparable group of age-matched, healthy women......, and the tissue examined for myosin ATPase activity. Further, the cross-sectional areas of the different fibre types were measured. In spite of using age-matched healthy men and women with a full complement of teeth, statistically significant sex differences were found among measures related to muscle function...... and some measures of facial morphology. Thus data from men and women should not be pooled uncritically. The greater bite force in men than women corresponded with the greater diameter and cross-sectional area of type II fibres. Further, the males had more anteriorly inclined mandibles and shorter anterior...

  2. Control of thumb force using surface functional electrical stimulation and muscle load sharing

    Science.gov (United States)

    2013-01-01

    Background Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of individual muscle forces, described by a sigmoidal muscle recruitment curve and a single force direction. Methods Five able bodied subjects and five stroke subjects were strapped in a custom built setup. The forces perpendicular to the thumb in response to FES applied to three thumb muscles were measured. We evaluated the feasibility of using recruitment curve based force vector maps in predicting output forces. In addition, we developed a closed loop force controller. Load sharing between the three muscles was used to solve the redundancy problem having three actuators to control forces in two dimensions. The thumb force was controlled towards target forces of 0.5 N and 1.0 N in multiple directions within the individual’s thumb work space. Hereby, the possibilities to use these force vector maps and the load sharing approach in feed forward and feedback force control were explored. Results The force vector prediction of the obtained model had small RMS errors with respect to the actual measured force vectors (0.22±0.17 N for the healthy subjects; 0.17±0.13 N for the stroke subjects). The stroke subjects showed a limited work range due to limited force production of the individual muscles. Performance of feed forward control without feedback, was better in healthy subjects than in stroke subjects. However, when feedback control was added performances were similar between the two groups. Feedback force control lead, especially for the stroke subjects, to a reduction in stationary errors, which improved performance. Conclusions Thumb muscle responses to FES can be described by a single force direction and a sigmoidal recruitment curve. Force in desired direction can be

  3. Advanced Magnetic Resonance Imaging techniques to probe muscle structure and function

    Science.gov (United States)

    Malis, Vadim

    Structural and functional Magnetic Resonance Imaging (MRI) studies of skeletal muscle allow the elucidation of muscle physiology under normal and pathological conditions. Continuing on the efforts of the Muscle Imaging and Modeling laboratory, the focus of the thesis is to (i) extend and refine two challenging imaging modalities: structural imaging using Diffusion Tensor Imaging (DTI) and functional imaging based on Velocity Encoded Phase Contrast Imaging (VE-PC) and (ii) apply these methods to explore age related structure and functional differences of the gastrocnemius muscle. Diffusion Tensor Imaging allows the study of tissue microstructure as well as muscle fiber architecture. The images, based on an ultrafast single shot Echo Planar Imaging (EPI) sequence, suffer from geometric distortions and low signal to noise ratio. A processing pipeline was developed to correct for distortions and to improve image Signal to Noise Ratio (SNR). DTI acquired on a senior and young cohort of subjects were processed through the pipeline and differences in DTI derived indices and fiber architecture between the two cohorts were explored. The DTI indices indicated that at the microstructural level, fiber atrophy was accompanied with a reduction in fiber volume fraction. At the fiber architecture level, fiber length and pennation angles decreased with age that potentially contribute to the loss of muscle force with age. Velocity Encoded Phase Contrast imaging provides tissue (e.g. muscle) velocity at each voxel which allows the study of strain and Strain Rate (SR) under dynamic conditions. The focus of the thesis was to extract 2D strain rate tensor maps from the velocity images and apply the method to study age related differences. The tensor mapping can potentially provide unique information on the extracellular matrix and lateral transmission the role of these two elements has recently emerged as important determinants of force loss with age. In the cross sectional study on

  4. Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

    Science.gov (United States)

    Fernandez-Gonzalo, R; Tesch, P A; Linnehan, R M; Kreider, R B; Di Salvo, V; Suarez-Arrones, L; Alomar, X; Mendez-Villanueva, A; Rodas, G

    2016-06-01

    This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (Phamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (Phamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Muscle Force-Velocity Relationships Observed in Four Different Functional Tests.

    Science.gov (United States)

    Zivkovic, Milena Z; Djuric, Sasa; Cuk, Ivan; Suzovic, Dejan; Jaric, Slobodan

    2017-02-01

    The aims of the present study were to investigate the shape and strength of the force-velocity relationships observed in different functional movement tests and explore the parameters depicting force, velocity and power producing capacities of the tested muscles. Twelve subjects were tested on maximum performance in vertical jumps, cycling, bench press throws, and bench pulls performed against different loads. Thereafter, both the averaged and maximum force and velocity variables recorded from individual trials were used for force-velocity relationship modeling. The observed individual force-velocity relationships were exceptionally strong (median correlation coefficients ranged from r = 0.930 to r = 0.995) and approximately linear independently of the test and variable type. Most of the relationship parameters observed from the averaged and maximum force and velocity variable types were strongly related in all tests (r = 0.789-0.991), except for those in vertical jumps (r = 0.485-0.930). However, the generalizability of the force-velocity relationship parameters depicting maximum force, velocity and power of the tested muscles across different tests was inconsistent and on average moderate. We concluded that the linear force-velocity relationship model based on either maximum or averaged force-velocity data could provide the outcomes depicting force, velocity and power generating capacity of the tested muscles, although such outcomes can only be partially generalized across different muscles.

  6. Regulation of muscle stem cell functions: a focus on the p38 MAPK signaling pathway

    Directory of Open Access Journals (Sweden)

    Jessica Segales

    2016-08-01

    Full Text Available Formation of skeletal muscle fibers (myogenesis during development and after tissue injury in the adult constitutes an excellent paradigm to investigate the mechanisms whereby environmental cues control gene expression programs in muscle stem cells (satellite cells by acting on transcriptional and epigenetic effectors. Here we will review the molecular mechanisms implicated in the transition of satellite cells throughout the distinct myogenic stages (i.e., activation from quiescence, proliferation, differentiation and self-renewal. We will also discuss recent findings on the causes underlying satellite cell functional decline with aging. In particular, our review will focus on the epigenetic changes underlying fate decisions and on how the p38 MAPK signaling pathway integrates the environmental signals at the chromatin to build up satellite cell adaptive responses during the process of muscle regeneration, and how these responses are altered in aging. A better comprehension of the signaling pathways connecting external and intrinsic factors will illuminate the path for improving muscle regeneration in the aged.

  7. Functional dysregulation of stem cells during aging: a focus on skeletal muscle stem cells.

    Science.gov (United States)

    García-Prat, Laura; Sousa-Victor, Pedro; Muñoz-Cánoves, Pura

    2013-09-01

    Aging of an organism is associated with the functional decline of tissues and organs, as well as a sharp decline in the regenerative capacity of stem cells. A prevailing view holds that the aging rate of an individual depends on the ratio of tissue attrition to tissue regeneration. Therefore, manipulations that favor the balance towards regeneration may prevent or delay aging. Skeletal muscle is a specialized tissue composed of postmitotic myofibers that contract to generate force. Satellite cells are the adult stem cells responsible for skeletal muscle regeneration. Recent studies on the biology of skeletal muscle and satellite cells in aging have uncovered the critical impact of systemic and niche factors on stem cell functionality and demonstrated the capacity of aged satellite cells to rejuvenate and increase their regenerative potential when exposed to a youthful environment. Here we review the current literature on the coordinated relationship between cell extrinsic and intrinsic factors that regulate the function of satellite cells, and ultimately determine tissue homeostasis and repair during aging, and which encourage the search for new anti-aging strategies. © 2013 The Authors Journal compilation © 2013 FEBS.

  8. Effects of inspiratory muscle training on respiratory function and repetitive sprint performance in wheelchair basketball players.

    Science.gov (United States)

    Goosey-Tolfrey, V; Foden, E; Perret, C; Degens, H

    2010-07-01

    There is considerable evidence that respiratory muscle training improves pulmonary function, quality of life and exercise performance in healthy athletic populations. The benefits for wheelchair athletes are less well understood. Therefore, in the present study, influence of inspiratory muscle training (IMT) on respiratory function and repetitive propulsive sprint performance in wheelchair basketball players was examined. Using a placebo-controlled design, 16 wheelchair athletes were divided to an experimental (IMT; n=8) or placebo (sham-IMT; n=8) group based on selective grouping criteria. 30 dynamic breaths were performed by the IMT group twice daily at a resistance equivalent to 50% maximum inspiratory pressure (MIP), and 60 slow breaths were performed by the sham-IMT group once a day at 15% MIP for a period of 6 weeks. In the IMT group, both MIP and maximum expiratory pressure (17% and 23%, respectively; ptraining device suggested "less breathlessness" and "less tightness in the chest during the training". Although there was no improvement in sprint performance, an improved respiratory muscle function and quality of life were reported by participants in both the IMT and sham-IMT groups.

  9. Brain Functional Connectivity is Different during VoluntaryConcentric and Eccentric Muscle Contraction

    Directory of Open Access Journals (Sweden)

    Wan X Yao

    2016-11-01

    Full Text Available Previous studies report greater activation in the cortical motor network in controlling eccentric contraction (EC than concentric contraction (CC of human skeletal muscles despite lower activation level of the muscle associated with EC. It is unknown, however, whether the strength of functional coupling between the primary motor cortex (M1 and other involved areas in the brain differs as voluntary movements are controlled by a network of regions in the primary, secondary and association cortices. Examining fMRI-based functional connectivity (FC offers an opportunity to measure strength of such coupling. To address the question, we examined functional MRI (fMRI data acquired during EC and CC (20 contractions each with similar movement distance and speed of the right first dorsal interosseous (FDI muscle in 11 young (20-32 years and healthy individuals and estimated FC between the M1 and a number of cortical regions in the motor control network. The major findings from the behavioral and fMRI-based FC analysis were that (1 no significant differences were seen in movement distance, speed and stability between the EC and CC; (2 significantly stronger mean FC was found for CC than EC. Our finding provides novel insights for a better understanding of the control mechanisms underlying voluntary movements produced by EC and CC. The finding is potentially helpful for guiding the development of targeted sport training and/or therapeutic programs for performance enhancement and injury prevention.

  10. Body composition of 80-years old men and women and its relation to muscle strength, physical activity and functional ability

    DEFF Research Database (Denmark)

    Pedersen, Agnes Nadelmann; Ovesen, L.; Schroll, M.

    2002-01-01

    , and physical activity and functional ability. BMI was related to body fat mass, and FFM was related to muscle strength. Muscle strength was related to mobility and PPT. Mobility and PPT were mutually related and were related to physical activity. CONCLUSION: Our cross sectional study did not support newly...

  11. Phase reversal of biomechanical functions and muscle activity in backward pedaling.

    Science.gov (United States)

    Ting, L H; Kautz, S A; Brown, D A; Zajac, F E

    1999-02-01

    Computer simulations of pedaling have shown that a wide range of pedaling tasks can be performed if each limb has the capability of executing six biomechanical functions, which are arranged into three pairs of alternating antagonistic functions. An Ext/Flex pair accelerates the limb into extension or flexion, a Plant/Dorsi pair accelerates the foot into plantarflexion or dorsiflexion, and an Ant/Post pair accelerates the foot anteriorly or posteriorly relative to the pelvis. Because each biomechanical function (i.e., Ext, Flex, Plant, Dorsi, Ant, or Post) contributes to crank propulsion during a specific region in the cycle, phasing of a muscle is hypothesized to be a consequence of its ability to contribute to one or more of the biomechanical functions. Analysis of electromyogram (EMG) patterns has shown that this biomechanical framework assists in the interpretation of muscle activity in healthy and hemiparetic subjects during forward pedaling. Simulations show that backward pedaling can be produced with a phase shift of 180 degrees in the Ant/Post pair. No phase shifts in the Ext/Flex and Plant/Dorsi pairs are then necessary. To further test whether this simple yet biomechanically viable strategy may be used by the nervous system, EMGs from 7 muscles in 16 subjects were measured during backward as well as forward pedaling. As predicted, phasing in vastus medialis (VM), tibialis anterior (TA), medial gastrocnemius (MG), and soleus (SL) were unaffected by pedaling direction, with VM and SL contributing to Ext, MG to Plant, and TA to Dorsi. In contrast, phasing in biceps femoris (BF) and semimembranosus (SM) were affected by pedaling direction, as predicted, compatible with their contribution to the directionally sensitive Post function. Phasing of rectus femoris (RF) was also affected by pedaling direction; however, its ability to contribute to the directionally sensitive Ant function may only be expressed in forward pedaling. RF also contributed significantly to

  12. The neuromechanical functional contractile properties of the thigh muscles measured using tensiomyography in male athletes and non-athletes

    Directory of Open Access Journals (Sweden)

    Toskić Lazar

    2016-01-01

    Full Text Available Involuntary neuromechanical muscle contractile properties, especially of the extensor muscles and knee joint flexors as the largest muscle groups of the caudal part of the body, play an important role in both everyday movement and sport. Based on these data we can obtain important information on the functional properties of muscles. The basic means of evaluation of the functional involuntary neuromechanical muscles contractile properties is the non-invasive tensiomyographic method (TMG. The aim of this study was to determine the differences between the involuntary neuromechanical contractile properties of the thigh muscles measured using the TMG method on a sample of male athletes and non-athletes. The sample of participants was made up of 17 athletes and 10 non-athletes. By applying the multivariate analysis of variance (MANOVA and the t-test, we achieved results which indicate that of the overall 30 variables, a difference was determined among 13 of them. Most of the differences were determined for the extensor muscles of the right knee, especially of the rectus femoris muscle. It was also shown that in addition to the main knee joint extensor muscle (rectus femoris the main knee joint flexor muscle (biceps femoris also takes part in the definition of the difference between athletes and non-athletes. The results have shown that the following variables: contraction time (Tc and delay contraction time (Td are the functional parameters for which the highest difference between athletes and non-athletes were determined (from t = -2.284, p < 0.05 for the vastus lateralis of the right leg to t = -4.018, p < 0.01 for the rectus femoris of the left leg. These results have shown that it is possible to determine the differences in the functional involuntary neuromechanical contractile properties of the thigh muscles among trained and untrained individuals using the tensiomyographic method, but at the same time indicated that these differences were very

  13. Tear function and ocular surface after Muller muscle-conjunctival resection.

    Science.gov (United States)

    Uğurbaş, Suat Hayri; Alpay, Atilla; Bahadır, Burak; Uğurbaş, Sılay Cantürk

    2014-05-01

    Muller muscle-conjunctival resection (MCR) is a surgical technique to correct mild and moderate ptosis. In this study, tear function tests and ocular surface are evaluated in patients who underwent unilateral surgery. Sixteen patients with normal preoperative tear function who underwent unilateral MCR were evaluated prospectively. The fellow eyes of the patients were taken as the control group. A dry eye assessment questionnaire, Schirmer testing, tear film break-up time, fluorescein stain, Rose-Bengal stain, and conjunctival impression cytology were used to assess the tear film functions and ocular surface changes in the operated and non-operated eyes. There was no statistically significant difference in the tear function tests and goblet cell densities between the operated and non-operated eyes. The results indicate that an MCR procedure has no apparent effect on tear function tests and goblet cell density in patients with normal preoperative tear function.

  14. Evaluation of Functional Correlation of Task-Specific Muscle Synergies with Motor Performance in Patients Poststroke

    Directory of Open Access Journals (Sweden)

    Si Li

    2017-07-01

    Full Text Available The central nervous system produces movements by activating specifically programmed muscle synergies that are also altered with injuries in the brain, such as stroke. In this study, we hypothesize that there exists a positive correlation between task-specific muscle synergy and motor functions at joint and task levels in patients following stroke. The purpose here is to define and evaluate neurophysiological metrics based on task-specific muscle synergy for assessing motor functions in patients. A patient group of 10 subjects suffering from stroke and a control group of nine age-matched healthy subjects were recruited to participate in this study. Electromyography (EMG signals and movement kinematics were recorded in patients and control subjects while performing arm reaching tasks. Muscle synergies of individual patients were extracted off-line from EMG records of each patient, and a baseline pattern of muscle synergy was obtained from the pooled EMG data of all nine control subjects. Peak velocities and movement durations of each reaching movement were computed from measured kinematics. Similarity indices of matching components to those of the baseline synergy were defined by synergy vectors and time profiles, respectively, as well as by a combined similarity of vector and time profile. Results showed that pathological synergies of patients were altered from the characteristics of baseline synergy with missing components, or varied vector patterns and time profiles. The kinematic performance measured by peak velocities and movement durations was significantly poorer for the patient group than the control group. In patients, all three similarity indices were found to correlate significantly to the kinematics of movements for the reaching tasks. The correlation to the Fugl-Meyer score of arm was the highest with the vector index, the lowest with the time profile index, and in between with the combined index. These findings illustrate that the

  15. Evoked EMG versus Muscle Torque during Fatiguing Functional Electrical Stimulation-Evoked Muscle Contractions and Short-Term Recovery in Individuals with Spinal Cord Injury

    Science.gov (United States)

    Estigoni, Eduardo H.; Fornusek, Che; Hamzaid, Nur Azah; Hasnan, Nazirah; Smith, Richard M.; Davis, Glen M.

    2014-01-01

    This study investigated whether the relationship between muscle torque and m-waves remained constant after short recovery periods, between repeated intervals of isometric muscle contractions induced by functional electrical stimulation (FES). Eight subjects with spinal cord injury (SCI) were recruited for the study. All subjects had their quadriceps muscles group stimulated during three sessions of isometric contractions separated by 5 min of recovery. The evoked-electromyographic (eEMG) signals, as well as the produced torque, were synchronously acquired during the contractions and during short FES bursts applied during the recovery intervals. All analysed m-wave variables changed progressively throughout the three contractions, even though the same muscle torque was generated. The peak to peak amplitude (PtpA), and the m-wave area (Area) were significantly increased, while the time between the stimulus artefact and the positive peak (PosT) were substantially reduced when the muscles became fatigued. In addition, all m-wave variables recovered faster and to a greater extent than did torque after the recovery intervals. We concluded that rapid recovery intervals between FES-evoked exercise sessions can radically interfere in the use of m-waves as a proxy for torque estimation in individuals with SCI. This needs to be further investigated, in addition to seeking a better understanding of the mechanisms of muscle fatigue and recovery. PMID:25479324

  16. Bion 11 Spaceflight Project: Effect of Weightlessness on Single Muscle Fiber Function in Rhesus Monkeys

    Science.gov (United States)

    Fitts, Robert H.; Romatowski, Janell G.; Widrick, Jeffrey J.; DeLaCruz, Lourdes

    1999-01-01

    Although it is well known that microgravity induces considerable limb muscle atrophy, little is known about how weightlessness alters cell function. In this study, we investigated how weightlessness altered the functional properties of single fast and slow striated muscle fibers. Physiological studies were carried out to test the hypothesis that microgravity causes fiber atrophy, a decreased peak force (Newtons), tension (Newtons/cross-sectional area) and power, an elevated peak rate of tension development (dp/dt), and an increased maximal shortening velocity (V(sub o)) in the slow type I fiber, while changes in the fast-twitch fiber are restricted to atrophy and a reduced peak force. For each fiber, we determined the peak force (P(sub o)), V(sub o), dp/dt, the force-velocity relationship, peak power, the power-force relationship, the force-pCa relationship, and fiber stiffness. Biochemical studies were carried out to assess the effects of weightlessness on the enzyme and substrate profile of the fast- and slow-twitch fibers. We predicted that microgravity would increase resting muscle glycogen and glycolytic metabolism in the slow fiber type, while the fast-twitch fiber enzyme profile would be unaltered. The increased muscle glycogen would in part result from an elevated hexokinase and glycogen synthase. The enzymes selected for study represent markers for mitochondrial function (citrate synthase and 0-hydroxyacyl-CoA dehydrogenase), glycolysis (Phosphofructokinase and lactate dehydrogenase), and fatty acid transport (Carnitine acetyl transferase). The substrates analyzed will include glycogen, lactate, adenosine triphosphate, and phosphocreatine.

  17. Respiratory muscle function in infants with spinal muscular atrophy type I.

    Science.gov (United States)

    Finkel, Richard S; Weiner, Daniel J; Mayer, Oscar H; McDonough, Joseph M; Panitch, Howard B

    2014-12-01

    To determine the feasibility and safety of respiratory muscle function testing in weak infants with a progressive neuromuscular disorder. Respiratory insufficiency is the major cause of morbidity and mortality in infants with spinal muscular atrophy type I (SMA-I). Tests of respiratory muscle strength, endurance, and breathing patterns can be performed safely in SMA-I infants. Useful data can be collected which parallels the clinical course of pulmonary function in SMA-I. An exploratory study of respiratory muscle function testing and breathing patterns in seven infants with SMA-I seen in our neuromuscular clinic. Measurements were made at initial study visit and, where possible, longitudinally over time. We measured maximal inspiratory (MIP) and transdiaphragmatic pressures, mean transdiaphragmatic pressure, airway occlusion pressure at 100 msec of inspiration, inspiratory and total respiratory cycle time, and aspects of relative thoracoabdominal motion using respiratory inductive plethysmography (RIP). The tension time index of the diaphragm and of the respiratory muscles, phase angle (Φ), phase relation during the total breath, and labored breathing index were calculated. Age at baseline study was 54-237 (median 131) days. Reliable data were obtained safely for MIP, phase angle, labored breathing index, and the invasive and non-invasive tension time indices, even in very weak infants. Data obtained corresponded to the clinical estimate of severity and predicted the need for respiratory support. The testing employed was both safe and feasible. Measurements of MIP and RIP are easily performed tests that are well tolerated and provide clinically useful information for infants with SMA-I. © 2014 Wiley Periodicals, Inc.

  18. Parameters and functional analysis of the deep epaxial muscles in the thoracic, lumbar and sacral regions of the equine spine.

    Science.gov (United States)

    García Liñeiro, J A; Graziotti, G H; Rodríguez Menéndez, J M; Ríos, C M; Affricano, N O; Victorica, C L

    2018-04-30

    The epaxial muscles produce intervertebral rotation in the transverse, vertical and axial axes. These muscles also counteract the movements induced by gravitational and inertial forces and movements produced by antagonistic muscles and the intrinsic muscles of the pelvic limb. Their fascicles are innervated by the dorsal branch of the spinal nerve, which corresponds to the metamere of its cranial insertion in the spinous process. The structure allows the function of the muscles to be predicted: those with long and parallel fibres have a shortening function, whereas the muscles with short and oblique fibres have an antigravity action. In the horse, the multifidus muscle of the thoracolumbar region extends in multiple segments of two to eight vertebral motion segments (VMS). Functionally, the multifidus muscle is considered a spine stabiliser, maintaining VMS neutrality during spine rotations. However, there is evidence of the structural and functional heterogeneity of the equine thoracolumbar multifidus muscle, depending on the VMS considered, related to the complex control of the required neuromuscular activity. Osteoarticular lesions of the spine have been directly related to asymmetries of the multifidus muscle. The lateral (LDSM) and medial (MDSM) dorsal sacrocaudal muscles may be included in the multifidus complex, the function of which is also unclear in the lumbosacral region. The functional parameters of maximum force (F max ), maximum velocity of contraction (V max ) and joint moment (M) of the multifidus muscles inserted in the 4th, 9th, 12th and 17th thoracic and 3rd and 4th lumbar vertebrae of six horses were studied postmortem (for example: 4MT4 indicates the multifidus muscle that crosses four metameres with cranial insertion in the T4 vertebra). Furthermore, the structural and functional characteristics of LDSM and MDSM were determined. Data were analysed by analysis of variance (anova) in a randomised complete block design (P ≤ 0.05). For some

  19. Effects of a deep-water running program on muscle function and functionality in elderly women community dwelling

    Directory of Open Access Journals (Sweden)

    Daisy Alberti

    2017-12-01

    Full Text Available Abstract AIMS The aim of the study was to determine the effects of deep-water running on muscle function and functionality in community dwelling old women. METHODS Older women (n=19 were randomly assigned to one of the two groups: deep-water running (DWR: n=09, 64.33±4.24 years, 75.15±12.53 kg, 160.45±7.52 cm; or control group CG: n=10, 64.40±4.22 years, 74.46±12.39 kg, 158.88±5.48 cm. The DWR group carried out 18 weeks of deep-water running, twice/week 50 min sessions. Dynamic isokinetic strength for the lower limb and functionality was assessed before and after intervention. RESULTS DWR group increased peak torque, total work and average power of the knee and hip flexors and extensors. Additionally showed better performance on gait speed, timed up and go test, five-times-sit-to-stand-test repetitions from a chair as well as the six-minute walk test. CONCLUSION The deep-water running program was effective to improve muscle function and functionality.

  20. Quantification of pelvic floor muscle strength in female urinary incontinence: A systematic review and comparison of contemporary methodologies.

    Science.gov (United States)

    Deegan, Emily G; Stothers, Lynn; Kavanagh, Alex; Macnab, Andrew J

    2018-01-01

    There remains no gold standard for quantification of voluntary pelvic floor muscle (PFM) strength, despite international guidelines that recommend PFM assessment in females with urinary incontinence (UI). Methods currently reported for quantification of skeletal muscle strength across disciplines are systematically reviewed and their relevance for clinical and academic use related to the pelvic floor are described. A systematic review via Medline, PubMed, CINHAL, and the Cochrane database using key terms for pelvic floor anatomy and function were cross referenced with skeletal muscle strength quantification from 1946 to 2016. Full text peer-reviewed articles in English having female subjects with incontinence were identified. Each study was analyzed for use of controls, type of methodology as direct or indirect measures, benefits, and limitations of the technique. A total of 1586 articles were identified of which 50 met the inclusion criteria. Nine methodologies of determining PFM strength were described including: digital palpation, perineometer, dynamometry, EMG, vaginal cones, ultrasonography, magnetic resonance imaging, urine stream interruption test, and the Colpexin pull test. Thirty-two percent lacked a control group. Technical refinements in both direct and indirect instrumentation for PFM strength measurement are allowing for sensitivity. However, the most common methods of quantification remain digital palpation and perineometry; techniques that pose limitations and yield subjective or indirect measures of muscular strength. Dynamometry has potential as an accurate and sensitive tool, but is limited by inability to assess PFM strength during dynamic movements. © 2017 Wiley Periodicals, Inc.

  1. Exposure to Gulf War Illness chemicals induces functional muscarinic receptor maladaptations in muscle nociceptors.

    Science.gov (United States)

    Cooper, B Y; Johnson, R D; Nutter, T J

    2016-05-01

    Chronic pain is a component of the multisymptom disease known as Gulf War Illness (GWI). There is evidence that pain symptoms could have been a consequence of prolonged and/or excessive exposure to anticholinesterases and other GW chemicals. We previously reported that rats exposed, for 8 weeks, to a mixture of anticholinesterases (pyridostigmine bromide, chlorpyrifos) and a Nav (voltage activated Na(+) channel) deactivation-inhibiting pyrethroid, permethrin, exhibited a behavior pattern that was consistent with a delayed myalgia. This myalgia-like behavior was accompanied by persistent changes to Kv (voltage activated K(+)) channel physiology in muscle nociceptors (Kv7, KDR). In the present study, we examined how exposure to the above agents altered the reactivity of Kv channels to a muscarinic receptor (mAChR) agonist (oxotremorine-M). Comparisons between muscle nociceptors harvested from vehicle and GW chemical-exposed rats revealed that mAChR suppression of Kv7 activity was enhanced in exposed rats. Yet in these same muscle nociceptors, a Stromatoxin-insensitive component of the KDR (voltage activated delayed rectifier K(+) channel) exhibited decreased sensitivity to activation of mAChR. We have previously shown that a unique mAChR-induced depolarization and burst discharge (MDBD) was exaggerated in muscle nociceptors of rats exposed to GW chemicals. We now provide evidence that both muscle and vascular nociceptors of naïve rats exhibit MDBD. Examination of the molecular basis of the MDBD in naïve animals revealed that while the mAChR depolarization was independent of Kv7, the action potential burst was modulated by Kv7 status. mAChR depolarizations were shown to be dependent, in part, on TRPA1. We argue that dysfunction of the MDBD could be a functional convergence point for maladapted ion channels and receptors consequent to exposure to GW chemicals. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Increasing taurine intake and taurine synthesis improves skeletal muscle function in the mdx mouse model for Duchenne muscular dystrophy.

    Science.gov (United States)

    Terrill, Jessica R; Pinniger, Gavin J; Graves, Jamie A; Grounds, Miranda D; Arthur, Peter G

    2016-06-01

    Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease associated with increased inflammation, oxidative stress and myofibre necrosis. Cysteine precursor antioxidants such as N-acetyl cysteine (NAC) and l-2-oxothiazolidine-4-carboxylate (OTC) reduce dystropathology in the mdx mouse model for DMD, and we propose this is via increased synthesis of the amino acid taurine. We compared the capacity of OTC and taurine treatment to increase taurine content of mdx muscle, as well as effects on in vivo and ex vivo muscle function, inflammation and oxidative stress. Both treatments increased taurine in muscles, and improved many aspects of muscle function and reduced inflammation. Taurine treatment also reduced protein thiol oxidation and was overall more effective, as OTC treatment reduced body and muscle weight, suggesting some adverse effects of this drug. These data suggest that increasing dietary taurine is a better candidate for a therapeutic intervention for DMD. Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease for which there is no widely available cure. Whilst the mechanism of loss of muscle function in DMD and the mdx mouse model are not fully understood, disruptions in intracellular calcium homeostasis, inflammation and oxidative stress are implicated. We have shown that protein thiol oxidation is increased in mdx muscle, and that the indirect thiol antioxidant l-2-oxothiazolidine-4-carboxylate (OTC), which increases cysteine availability, decreases pathology and increases in vivo strength. We propose that the protective effects of OTC are a consequence of conversion of cysteine to taurine, which has itself been shown to be beneficial to mdx pathology. This study compares the efficacy of taurine with OTC in decreasing dystropathology in mdx mice by measuring in vivo and ex vivo contractile function and measurements of inflammation and protein thiol oxidation. Increasing the taurine content of mdx muscle improved both in vivo and ex

  3. Association between muscle function, cognitive state, depression symptoms and quality of life of older people: evidence from clinical practice.

    Science.gov (United States)

    Gariballa, Salah; Alessa, Awad

    2018-04-01

    Although low muscle function/strength is an important predictor of poor clinical outcome in older patients, information on its impact on mental health in clinical practice is still lacking. The aim of this report is to measure the impact of low muscle function measured by handgrip strength on mental health of older people during both acute illness and recovery. Four hundred and thirty-two randomly selected hospitalized older patients had their baseline demographic and clinical characteristics assessed within 72 h of admission, at 6 weeks and at 6 months. Low muscle strength-handgrip was defined using the European Working Group criteria. Mental health outcome measures including cognitive state, depression symptoms and quality of life were also measured. Among the 432 patients recruited, 308 (79%) had low muscle strength at baseline. Corresponding figures at 6 weeks and at 6 months were 140 (73%) and 158 (75%). Patients with poor muscle strength were significantly older with increased disability and poor nutritional status compared with those with normal muscle strength. After adjustment for age, gender, disability, comorbidity including severity of acute illness and body mass index patients with low muscle strength had worse cognitive function, quality of life and higher depression symptoms compared with those with normal muscle strength over a 6-month period (p older people is associated with poor cognitive state and quality of life and increased depression symptoms during both acute illness and recovery.

  4. [Muscle and function management by the physiotherapist in orthodontic and orthodonto-surgical treatment. Oral myofunctional rehabilitation].

    Science.gov (United States)

    Girard, Marion; Leroux, Claire

    2015-03-01

    Can we hope to dispense with muscle and function management in orthodontic and orthodonto-surgical treatment plans? How can the specialized physiotherapist assist, facilitate and stabilize the work done by the orthodontist and maxillo-facial surgeon and help avoid relapses? Treatment aims to achieve dental alignment and occlusal balance in direct association with balance of the tongue muscles, cutaneous muscles, masticatory and postural muscles and functions in the orofacial region. Restoration of balance between agonist and antagonist muscles is achieved by relaxing contracted muscles and by gradually building up weak muscle tone. If effective and lasting treatment results are to be obtained, active patient participation is mandatory during rehabilitation of oro-maxillo-facial disorders and must encompass the tongue, lips, cheeks, masticatory system, ventilation and general posture as well as management of the parafunctions. These procedures are essential in dentofacial orthopedic treatment of both children and adults. Practical cases will be used to demonstrate the contribution that myofunctional rehabilitation can make. Regarding natural functions, very satisfactory results are obtained provided patients do daily muscle exercises and day-long training in the correct postures and practical drills they have been taught over a period of at least six months and under the supervision of the physiotherapist. © EDP Sciences, SFODF, 2015.

  5. Genetic and Environmental Influences on Pulmonary Function and Muscle Strength: The Chinese Twin Study of Aging

    DEFF Research Database (Denmark)

    Tian, Xiaocao; Xu, Chunsheng; Wu, Yili

    2017-01-01

    Genetic and environmental influences on predictors of decline in daily functioning, including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), handgrip, and five-times-sit-to-stand test (FTSST), have not been addressed in the aging Chinese population. We performed classical twin...... was moderate for FEV1, handgrip, and FTSST (55-60%) but insignificant for FVC. Only FVC showed moderate control, with shared environmental factors accounting for about 50% of the total variance. In contrast, all measures of pulmonary function and muscle strength showed modest influences from the unique...

  6. Overexpression of functional TrkA receptors after internalisation in human airway smooth muscle cells.

    Science.gov (United States)

    Freund-Michel, Véronique; Frossard, Nelly

    2008-10-01

    Trafficking of the TrkA receptor after stimulation by NGF is of emerging importance in structural cells in the context of airway inflammatory diseases. We have recently reported the expression of functional TrkA receptors in human airway smooth muscle cells (HASMC). We have here studied the TrkA trafficking mechanisms in these cells. TrkA disappearance from the cell membrane was induced within 5 min of NGF (3pM) stimulation. Co-immunoprecipitation of clathrin-TrkA was revealed, and TrkA internalisation inhibited either by clathrin inhibitors or by siRNA inducing downregulation of endogenous clathrin. TrkA internalised receptors were totally degraded in lysosomes, with no recycling phenomenon. Newly synthesized TrkA receptors were thereafter re-expressed at the cell membrane within 10 h. TrkA re-synthesis was inhibited by blockade of clathrin-dependent internalisation, but not of TrkA receptors lysosomal degradation. Finally, we observed that NGF multiple stimulations progressively increased TrkA expression in HASMC, which was associated with an increase in NGF/TrkA-dependent proliferation. In conclusion, we show here the occurrence of clathrin-dependent TrkA internalisation and lysosomal degradation in the airway smooth muscle, followed by upregulated re-synthesis of functional TrkA receptors and increased proliferative effect in the human airway smooth muscle. This may have pathophysiological consequences in airway inflammatory diseases.

  7. Analysis of Skeletal Muscle Metrics as Predictors of Functional Task Performance

    Science.gov (United States)

    Ryder, Jeffrey W.; Buxton, Roxanne E.; Redd, Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle J.; Fiedler, James; Ploutz-Snyder, Robert J.; Bloomberg, Jacob J.; Ploutz-Snyder, Lori L.

    2010-01-01

    PURPOSE: The ability to predict task performance using physiological performance metrics is vital to ensure that astronauts can execute their jobs safely and effectively. This investigation used a weighted suit to evaluate task performance at various ratios of strength, power, and endurance to body weight. METHODS: Twenty subjects completed muscle performance tests and functional tasks representative of those that would be required of astronauts during planetary exploration (see table for specific tests/tasks). Subjects performed functional tasks while wearing a weighted suit with additional loads ranging from 0-120% of initial body weight. Performance metrics were time to completion for all tasks except hatch opening, which consisted of total work. Task performance metrics were plotted against muscle metrics normalized to "body weight" (subject weight + external load; BW) for each trial. Fractional polynomial regression was used to model the relationship between muscle and task performance. CONCLUSION: LPMIF/BW is the best predictor of performance for predominantly lower-body tasks that are ambulatory and of short duration. LPMIF/BW is a very practical predictor of occupational task performance as it is quick and relatively safe to perform. Accordingly, bench press work best predicts hatch-opening work performance.

  8. Skeletal Muscle Ultrasonography in Nutrition and Functional Outcome Assessment of Critically Ill Children: Experience and Insights From Pediatric Disease and Adult Critical Care Studies [Formula: see text].

    Science.gov (United States)

    Ong, Chengsi; Lee, Jan Hau; Leow, Melvin K S; Puthucheary, Zudin A

    2017-09-01

    Evidence suggests that critically ill children develop muscle wasting, which could affect outcomes. Muscle ultrasound has been used to track muscle wasting and association with outcomes in critically ill adults but not children. This review aims to summarize methodological considerations of muscle ultrasound, structural findings, and possibilities for its application in the assessment of nutrition and functional outcomes in critically ill children. Medline, Embase, and CINAHL databases were searched up until April 2016. Articles describing skeletal muscle ultrasound in children and critically ill adults were analyzed qualitatively for details on techniques and findings. Thickness and cross-sectional area of various upper and lower body muscles have been studied to quantify muscle mass and detect muscle changes. The quadriceps femoris muscle is one of the most commonly measured muscles due to its relation to mobility and is sensitive to changes over time. However, the margin of error for quadriceps thickness is too wide to reliably detect muscle changes in critically ill children. Muscle size and its correlation with strength and function also have not yet been studied in critically ill children. Echogenicity, used to detect compromised muscle structure in neuromuscular disease, may be another property worth studying in critically ill children. Muscle ultrasound may be useful in detecting muscle wasting in critically ill children but has not been shown to be sufficiently reliable in this population. Further study of the reliability and correlation with functional outcomes and nutrition intake is required before muscle ultrasound is routinely employed in critically ill children.

  9. Architecture and functional ecology of the human gastrocnemius muscle-tendon unit.

    Science.gov (United States)

    Butler, Erin E; Dominy, Nathaniel J

    2016-04-01

    The gastrocnemius muscle-tendon unit (MTU) is central to human locomotion. Structural variation in the human gastrocnemius MTU is predicted to affect the efficiency of locomotion, a concept most often explored in the context of performance activities. For example, stiffness of the Achilles tendon varies among individuals with different histories of competitive running. Such a finding highlights the functional variation of individuals and raises the possibility of similar variation between populations, perhaps in response to specific ecological or environmental demands. Researchers often assume minimal variation in human populations, or that industrialized populations represent the human species as well as any other. Yet rainforest hunter-gatherers, which often express the human pygmy phenotype, contradict such assumptions. Indeed, the human pygmy phenotype is a potential model system for exploring the range of ecomorphological variation in the architecture of human hindlimb muscles, a concept we review here. © 2015 Anatomical Society.

  10. High-intensity strength training improves function of chronically painful muscles

    DEFF Research Database (Denmark)

    Andersen, Lars L; Andersen, Christoffer H; Skotte, Jørgen H

    2014-01-01

    AIM: This study investigates consequences of chronic neck pain on muscle function and the rehabilitating effects of contrasting interventions. METHODS: Women with trapezius myalgia (MYA, n = 42) and healthy controls (CON, n = 20) participated in a case-control study. Subsequently MYA were...... randomized to 10 weeks of specific strength training (SST, n = 18), general fitness training (GFT, n = 16), or a reference group without physical training (REF, n = 8). Participants performed tests of 100 consecutive cycles of 2 s isometric maximal voluntary contractions (MVC) of shoulder elevation followed...... MYA and CON. In the intervention study, SST improved all force parameters significantly more than the two other groups, to levels comparable to that of CON. This was seen along with muscle fiber hypertrophy and increased capillarization. CONCLUSION: Women with trapezius myalgia have lower strength...

  11. Effects of ageing on single muscle fibre contractile function following short-term immobilisation

    DEFF Research Database (Denmark)

    Hvid, Lars G; Ortenblad, Niels; Aagaard, Per

    2011-01-01

    Very little attention has been given to the combined effects of healthy ageing and short-term disuse on the contractile function of human single muscle fibres. Therefore, the present study investigated the effects of 2 weeks of lower limb cast immobilisation (i.e. disuse) on selected contractile...... IIa: young 18% and old 25%; P selective decrease in Ca(2+) sensitivity in MHC IIa fibres of young (P ....05), respectively. In conclusion, 2 weeks of lower limb immobilisation caused greater impairments in single muscle fibre force and specific force in MHC IIa than MHC I fibres independently of age. In contrast, immobilisation-induced changes in Ca(2+) sensitivity that were dependent on age and MHC isoform....

  12. Effects of proprioceptive circuit exercise on knee joint pain and muscle function in patients with knee osteoarthritis.

    Science.gov (United States)

    Ju, Sung-Bum; Park, Gi Duck; Kim, Sang-Soo

    2015-08-01

    [Purpose] This study applied proprioceptive circuit exercise to patients with degenerative knee osteoarthritis and examined its effects on knee joint muscle function and the level of pain. [Subjects] In this study, 14 patients with knee osteoarthritis in two groups, a proprioceptive circuit exercise group (n = 7) and control group (n = 7), were examined. [Methods] IsoMed 2000 (D&R Ferstl GmbH, Hemau, Germany) was used to assess knee joint muscle function, and a Visual Analog Scale was used to measure pain level. [Results] In the proprioceptive circuit exercise group, knee joint muscle function and pain levels improved significantly, whereas in the control group, no significant improvement was observed. [Conclusion] A proprioceptive circuit exercise may be an effective way to strengthen knee joint muscle function and reduce pain in patients with knee osteoarthritis.

  13. Curvilinear bodies are associated with adverse effects on muscle function but not with hydroxychloroquine dosing.

    Science.gov (United States)

    Khoo, Thomas; Otto, Sophia; Smith, Caroline; Koszyca, Barbara; Lester, Sue; Blumbergs, Peter; Limaye, Vidya

    2017-03-01

    The clinical significance of curvilinear bodies (CB) seen in association with hydroxychloroquine (HCQ) therapy is uncertain. Patients with CB on muscle biopsy performed between 2006 and the present were identified, and their clinical features including body mass index and cumulative HCQ dose were recorded. A control group of 16 patients with idiopathic inflammatory myositis (IIM) on HCQ at time of biopsy but without evidence of CB was identified. Nineteen patients with CB were identified; details were available for 18. Among patients with CB, 7/18 also had IIM. Seven out of ten patients with CB who did not have IIM or MHCI/II expression had proximal weakness; 7/11 had raised serum creatinine kinase (CK) levels. There was no difference in body weight (p = 0.47), body mass index (p = 0.93), cumulative HCQ dose (p = 0.52) or cumulative dose adjusted for body weight (p = 0.39) or body mass index (p = 0.32) between patients with CB and controls. Patients with CB had lower median CK levels than controls (p = 0.034). Weakness was present in 12/17 patients and 12/16 controls (p = 1.0). Concurrent proton-pump inhibitors were co-prescribed in 12/18 (67 %) patients with CB and in 6/16 (38 %) controls (p = 0.17). Development of CB does not appear to be related to cumulative HCQ dose or body weight. Patients with CB frequently have muscle weakness in the absence of MHC1 expression suggesting a role for non-immune mechanisms of muscle injury. A high proportion of patients with CB are co-prescribed proton-pump inhibitors raising the possibility that co-prescription of both agents may disrupt lysosomal function and adversely affect muscle function.

  14. Reliability and Measurement Error of Tensiomyography to Assess Mechanical Muscle Function: A Systematic Review.

    Science.gov (United States)

    Martín-Rodríguez, Saúl; Loturco, Irineu; Hunter, Angus M; Rodríguez-Ruiz, David; Munguia-Izquierdo, Diego

    2017-12-01

    Martín-Rodríguez, S, Loturco, I, Hunter, AM, Rodríguez-Ruiz, D, and Munguia-Izquierdo, D. Reliability and measurement error of tensiomyography to assess mechanical muscle function: A systematic review. J Strength Cond Res 31(12): 3524-3536, 2017-Interest in studying mechanical skeletal muscle function through tensiomyography (TMG) has increased in recent years. This systematic review aimed to (a) report the reliability and measurement error of all TMG parameters (i.e., maximum radial displacement of the muscle belly [Dm], contraction time [Tc], delay time [Td], half-relaxation time [½ Tr], and sustained contraction time [Ts]) and (b) to provide critical reflection on how to perform accurate and appropriate measurements for informing clinicians, exercise professionals, and researchers. A comprehensive literature search was performed of the Pubmed, Scopus, Science Direct, and Cochrane databases up to July 2017. Eight studies were included in this systematic review. Meta-analysis could not be performed because of the low quality of the evidence of some studies evaluated. Overall, the review of the 9 studies involving 158 participants revealed high relative reliability (intraclass correlation coefficient [ICC]) for Dm (0.91-0.99); moderate-to-high ICC for Ts (0.80-0.96), Tc (0.70-0.98), and ½ Tr (0.77-0.93); and low-to-high ICC for Td (0.60-0.98), independently of the evaluated muscles. In addition, absolute reliability (coefficient of variation [CV]) was low for all TMG parameters except for ½ Tr (CV = >20%), whereas measurement error indexes were high for this parameter. In conclusion, this study indicates that 3 of the TMG parameters (Dm, Td, and Tc) are highly reliable, whereas ½ Tr demonstrate insufficient reliability, and thus should not be used in future studies.

  15. Comparative functional anatomy of hindlimb muscles and bones with reference to aquatic adaptation of the sea otter.

    Science.gov (United States)

    Mori, Kent; Suzuki, Satoshi; Koyabu, Daisuke; Kimura, Junpei; Han, Sung-Yong; Endo, Hideki

    2015-05-01

    Although the sea otter (Enhydra lutris) is a complete aquatic species, spending its entire life in the ocean, it has been considered morphologically to be a semi-aquatic animal. This study aimed to clarify the unique hindlimb morphology and functional adaptations of E. lutris in comparison to other Mustelidae species. We compared muscle mass and bone measurements of five Mustelidae species: the sea otter, Eurasian river otter (Lutra lutra), American mink (Neovison vison), Japanese weasel (Mustela itatsi) and Siberian weasel (M. sibirica). In comparison with the other 4 species, E. lutris possessed significantly larger gluteus, popliteus and peroneus muscles, but smaller adductor and ischiopubic muscles. The popliteus muscle may act as a medial rotator of the crus, and the peroneus muscle may act as an abductor of the fifth toe and/or the pronator of the foot. The bundles of the gluteus superficialis muscle of E. lutris were fused with those of the tensor fasciae latae muscle and gluteofemoralis muscles, and they may play a role in femur abduction. These results suggest that E. lutris uses the abducted femur, medially rotated crus, eversion of the ankle and abducted fifth digit or extended interdigital web as a powerful propulsion generator. Therefore, we conclude that E. lutris is a complete aquatic animal, possessing differences in the proportions of the hindlimb muscles compared with those in other semi-aquatic and terrestrial mustelids.

  16. Functional evaluation of artificial skeletal muscle tissue constructs fabricated by a magnetic force-based tissue engineering technique.

    Science.gov (United States)

    Yamamoto, Yasunori; Ito, Akira; Fujita, Hideaki; Nagamori, Eiji; Kawabe, Yoshinori; Kamihira, Masamichi

    2011-01-01

    Skeletal muscle tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional artificial skeletal muscle tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the artificial tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the artificial tissue constructs contracted to generate a physical force (the maximum twitch force, 33.2 μN [1.06 mN/mm2]). Rheobase and chronaxie of the tissue were determined as 4.45 V and 0.72 ms, respectively. These results indicate that the artificial skeletal muscle tissue constructs fabricated in this study were physiologically functional and the data obtained for the evaluation of their functional properties may provide useful information for future skeletal muscle tissue engineering studies.

  17. Genes Whose Gain or Loss-Of-Function Increases Skeletal Muscle Mass in Mice: A Systematic Literature Review

    Directory of Open Access Journals (Sweden)

    Sander A. J. Verbrugge

    2018-05-01

    Full Text Available Skeletal muscle mass differs greatly in mice and humans and this is partially inherited. To identify muscle hypertrophy candidate genes we conducted a systematic review to identify genes whose experimental loss or gain-of-function results in significant skeletal muscle hypertrophy in mice. We found 47 genes that meet our search criteria and cause muscle hypertrophy after gene manipulation. They are from high to small effect size: Ski, Fst, Acvr2b, Akt1, Mstn, Klf10, Rheb, Igf1, Pappa, Ppard, Ikbkb, Fstl3, Atgr1a, Ucn3, Mcu, Junb, Ncor1, Gprasp1, Grb10, Mmp9, Dgkz, Ppargc1a (specifically the Ppargc1a4 isoform, Smad4, Ltbp4, Bmpr1a, Crtc2, Xiap, Dgat1, Thra, Adrb2, Asb15, Cast, Eif2b5, Bdkrb2, Tpt1, Nr3c1, Nr4a1, Gnas, Pld1, Crym, Camkk1, Yap1, Inhba, Tp53inp2, Inhbb, Nol3, Esr1. Knock out, knock down, overexpression or a higher activity of these genes causes overall muscle hypertrophy as measured by an increased muscle weight or cross sectional area. The mean effect sizes range from 5 to 345% depending on the manipulated gene as well as the muscle size variable and muscle investigated. Bioinformatical analyses reveal that Asb15, Klf10, Tpt1 are most highly expressed hypertrophy genes in human skeletal muscle when compared to other tissues. Many of the muscle hypertrophy-regulating genes are involved in transcription and ubiquitination. Especially genes belonging to three signaling pathways are able to induce hypertrophy: (a Igf1-Akt-mTOR pathway, (b myostatin-Smad signaling, and (c the angiotensin-bradykinin signaling pathway. The expression of several muscle hypertrophy-inducing genes and the phosphorylation of their protein products changes after human resistance and high intensity exercise, in maximally stimulated mouse muscle or in overloaded mouse plantaris.

  18. [Relation between physical activity, muscle function and IGF-1, testosterone and DHEAS concentrations in the elderly].

    Science.gov (United States)

    Bonnefoy, M; Patricot, M C; Lacour, J R; Rahmani, A; Berthouze, S; Kostka, T

    2002-10-01

    Lower amounts of circulating anabolic hormones are thought to accelerate the age related decline in muscle mass and function. Replacement therapies are promising interventions but there are problems with these therapies. Thus alternative strategies should be developed. The age related changes in hormonal status may be probably influenced by exercise. The purpose of this study was: a) to confirm with other methods, more adapted for elderly people, the results of a previous study that has shown relationship between physical activity (PA) and quadriceps muscle function with dehydroepiandrosterone sulphate (DHEAS), insulin like growth factor-1 (IGF-1). Quadriceps muscle power (Pmax) is measured in this new work with a recently developed leg extensor machine and, b) to complete the results of the first study examining simultaneously the relationship between PA, Pmax and cardiorespiratory fitness (VO2max) with DHEAS, IGF-1 and testosterone in a group of healthy elderly people. Fifty independent, community dwelling elderly subjects (25 mens and 25 womens) aged from 66 to 84 volunteered to participate in the study. PA was evaluated by the questionnaire and expressed using two activity indices: mean habitual daily energy expenditure (MHDEE) and the daily energy expenditure corresponding to leisure time sports activities (Sports Activity). Pmax and optimal shortening velocity (vopt) were measured on a Ergopower dynamometer. The Pmax was expressed relative to body mass, Pmax/kg (W kg-1), and relative to the mass of the two quadriceps muscles, Pmax/Quadr (W.kgQuadr-1). VO2max has been measured during a maximal treadmill exercise. In women, IGF-1 correlated significantly with MHDEE (r = 0.54, P = 0.004), Pmax/kg (r = 0.54, P = 0.004) and Pmax/Quadr (r = 0.46, P = 0.02), whereas DHEAS with MHDEE (r = 0.54, P = 0.004), Sports Activity (r = 0.65, P < 0.001), VO2max (r = 0.46, P = 0.02), Pmax/kg (r = 0.46, P = 0.02) and Pmax/Quadr (r = 0.55, P = 0.004). No such correlation was

  19. Unsteady locomotion: integrating muscle function with whole body dynamics and neuromuscular control

    Science.gov (United States)

    Biewener, Andrew A.; Daley, Monica A.

    2009-01-01

    Summary By integrating studies of muscle function with analysis of whole body and limb dynamics, broader appreciation of neuromuscular function can be achieved. Ultimately, such studies need to address non-steady locomotor behaviors relevant to animals in their natural environments. When animals move slowly they likely rely on voluntary coordination of movement involving higher brain centers. However, when moving fast, their movements depend more strongly on responses controlled at more local levels. Our focus here is on control of fast-running locomotion. A key observation emerging from studies of steady level locomotion is that simple spring-mass dynamics, which help to economize energy expenditure, also apply to stabilization of unsteady running. Spring-mass dynamics apply to conditions that involve lateral impulsive perturbations, sudden changes in terrain height, and sudden changes in substrate stiffness or damping. Experimental investigation of unsteady locomotion is challenging, however, due to the variability inherent in such behaviors. Another emerging principle is that initial conditions associated with postural changes following a perturbation define different context-dependent stabilization responses. Distinct stabilization modes following a perturbation likely result from proximo-distal differences in limb muscle architecture, function and control strategy. Proximal muscles may be less sensitive to sudden perturbations and appear to operate, in such circumstances, under feed-forward control. In contrast, multiarticular distal muscles operate, via their tendons, to distribute energy among limb joints in a manner that also depends on the initial conditions of limb contact with the ground. Intrinsic properties of these distal muscle–tendon elements, in combination with limb and body dynamics, appear to provide rapid initial stabilizing mechanisms that are often consistent with spring-mass dynamics. These intrinsic mechanisms likely help to simplify the

  20. Masticatory biomechanics of the Laotian rock rat, Laonastes aenigmamus, and the function of the zygomaticomandibularis muscle

    Directory of Open Access Journals (Sweden)

    Philip G. Cox

    2013-09-01

    Full Text Available The Laotian rock rat, Laonastes aenigmamus, is one of the most recently discovered species of rodent, and displays a cranial morphology that is highly specialised. The rostrum of L. aenigmamus is exceptionally elongate and bears a large attachment site for the infraorbital portion of the zygomaticomandibularis muscle (IOZM, which is particularly well-developed in this species. In this study, we used finite element analysis to investigate the biomechanical performance of the Laotian rock rat cranium and to elucidate the function of the IOZM. A finite element model of the skull of L. aenigmamus was constructed and solved for biting on each of the teeth (incisors, premolar and molars. Further load cases were created and solved in which the origin of the IOZM had been moved anteriorly and posteriorly along the rostrum. Finally, a set of load cases were produced in which the IOZM was removed entirely, and its force was redistributed between the remaining masticatory muscles. The analysis showed that, during biting, the most stressed areas of the skull were the zygomatic and orbital regions. Compared to other rodents, L. aenigmamus is highly efficient at incisor gnawing, but less efficient at molar chewing. However, a relatively constant bite force across the molar tooth row may be an adaptation to folivory. Movement of the origin of the IOZM had little on the patterns of von Mises stresses, or the overall stress experienced by the cranium. However, removal of the IOZM had a substantial effect on the total deformation experienced by the skull. In addition, the positioning and presence of the IOZM had large impact on bite force. Moving the IOZM origin to the anterior tip of the rostrum led to a substantially reduced bite force at all teeth. This was hypothesised to be a result of the increasing horizontal component to the pull of this muscle as it is moved anteriorly along the rostrum. Removal of the IOZM also resulted in reduced bite force, even when

  1. Whey Proteins Are More Efficient than Casein in the Recovery of Muscle Functional Properties following a Casting Induced Muscle Atrophy

    Science.gov (United States)

    Martin, Vincent; Ratel, Sébastien; Siracusa, Julien; Le Ruyet, Pascale; Savary-Auzeloux, Isabelle; Combaret, Lydie; Guillet, Christelle; Dardevet, Dominique

    2013-01-01

    The purpose of this study was to investigate the effect of whey supplementation, as compared to the standard casein diet, on the recovery of muscle functional properties after a casting-induced immobilization period. After an initial (I0) evaluation of the contractile properties of the plantarflexors (isometric torque-frequency relationship, concentric power-velocity relationship and a fatigability test), the ankle of 20 male adult rats was immobilized by casting for 8 days. During this period, rats were fed a standard diet with 13% of casein (CAS). After cast removal, rats received either the same diet or a diet with 13% of whey proteins (WHEY). A control group (n = 10), non-immobilized but pair-fed to the two other experimental groups, was also studied and fed with the CAS diet. During the recovery period, contractile properties were evaluated 7 (R7), 21 (R21) and 42 days (R42) after cast removal. The immobilization procedure induced a homogeneous depression of average isometric force at R7 (CAS: − 19.0±8.2%; WHEY: − 21.7±8.4%; P<0.001) and concentric power (CAS: − 26.8±16.4%, P<0.001; WHEY: − 13.5±21.8%, P<0.05) as compared to I0. Conversely, no significant alteration of fatigability was observed. At R21, isometric force had fully recovered in WHEY, especially for frequencies above 50 Hz, whereas it was still significantly depressed in CAS, where complete recovery occurred only at R42. Similarly, recovery of concentric power was faster at R21 in the 500−700°/s range in the WHEY group. These results suggest that recovery kinetics varied between diets, the diet with the whey proteins promoting a faster recovery of isometric force and concentric power output as compared to the casein diet. These effects were more specifically observed at force level and movement velocities that are relevant for functional abilities, and thus natural locomotion. PMID:24069411

  2. Validation of Skeletal Muscle cis-Regulatory Module Predictions Reveals Nucleotide Composition Bias in Functional Enhancers

    Science.gov (United States)

    Kwon, Andrew T.; Chou, Alice Yi; Arenillas, David J.; Wasserman, Wyeth W.

    2011-01-01

    We performed a genome-wide scan for muscle-specific cis-regulatory modules (CRMs) using three computational prediction programs. Based on the predictions, 339 candidate CRMs were tested in cell culture with NIH3T3 fibroblasts and C2C12 myoblasts for capacity to direct selective reporter gene expression to differentiated C2C12 myotubes. A subset of 19 CRMs validated as functional in the assay. The rate of predictive success reveals striking limitations of computational regulatory sequence analysis methods for CRM discovery. Motif-based methods performed no better than predictions based only on sequence conservation. Analysis of the properties of the functional sequences relative to inactive sequences identifies nucleotide sequence composition can be an important characteristic to incorporate in future methods for improved predictive specificity. Muscle-related TFBSs predicted within the functional sequences display greater sequence conservation than non-TFBS flanking regions. Comparison with recent MyoD and histone modification ChIP-Seq data supports the validity of the functional regions. PMID:22144875

  3. Validation of skeletal muscle cis-regulatory module predictions reveals nucleotide composition bias in functional enhancers.

    Directory of Open Access Journals (Sweden)

    Andrew T Kwon

    2011-12-01

    Full Text Available We performed a genome-wide scan for muscle-specific cis-regulatory modules (CRMs using three computational prediction programs. Based on the predictions, 339 candidate CRMs were tested in cell culture with NIH3T3 fibroblasts and C2C12 myoblasts for capacity to direct selective reporter gene expression to differentiated C2C12 myotubes. A subset of 19 CRMs validated as functional in the assay. The rate of predictive success reveals striking limitations of computational regulatory sequence analysis methods for CRM discovery. Motif-based methods performed no better than predictions based only on sequence conservation. Analysis of the properties of the functional sequences relative to inactive sequences identifies nucleotide sequence composition can be an important characteristic to incorporate in future methods for improved predictive specificity. Muscle-related TFBSs predicted within the functional sequences display greater sequence conservation than non-TFBS flanking regions. Comparison with recent MyoD and histone modification ChIP-Seq data supports the validity of the functional regions.

  4. Overactive pelvic floor muscles (OPFM): improving diagnostic accuracy with clinical examination and functional studies.

    Science.gov (United States)

    Aw, Hau Choong; Ranasinghe, Weranja; Tan, Philip Huang Min; O'Connell, Helen E

    2017-07-01

    To identify the functional correlation of overactive pelvic floor muscles (OPFM) with cystoscopic and fluoroscopic urodynamic studies (FUDS), including urethral pressure measurements. Patients refractory to conservative therapy including bladder retraining, medications and pelvic muscle exercises for a variety of gamut of storage and voiding disorders were evaluated. Prospective data for 201 patients across both genders who underwent flexible cystoscopy and urodynamics for lower urinary tract symptoms (LUTS) refractory to conservative management between 01 Jan 2014 and 01 Jan 2016 was collected. Factors studied included history of LUTS, voiding patterns, physical examination, cystoscopic findings and functional studies, with maximum urethral closing pressure (MUCP). A total of 201 were patients recruited. The 85 were diagnosed with OPFM based on clinical presentation and presence of pelvic floor tenderness on examination. Significant differences were noted on functional studies with FUDS and urethral pressure measurement. Subjects with pelvic floor tenderness were found to have a higher (MUCP) at 93.1 cm H2O compared to 80.6 cm H2O (P=0.015). There are distinct characteristics of OPFM on clinical examination and functional studies, in particular MUCP. In patients refractory to conservative treatments, specific urodynamics tests are useful in sub-categorising patients. When OPFM is diagnosed, the impact on patient management is significant, and targeted intervention with pelvic floor physiotherapy is central in the multimodal approach of this complex condition.

  5. Cytokine-induced differentiation of multipotent adult progenitor cells into functional smooth muscle cells.

    Science.gov (United States)

    Ross, Jeffrey J; Hong, Zhigang; Willenbring, Ben; Zeng, Lepeng; Isenberg, Brett; Lee, Eu Han; Reyes, Morayma; Keirstead, Susan A; Weir, E Kenneth; Tranquillo, Robert T; Verfaillie, Catherine M

    2006-12-01

    Smooth muscle formation and function are critical in development and postnatal life. Hence, studies aimed at better understanding SMC differentiation are of great importance. Here, we report that multipotent adult progenitor cells (MAPCs) isolated from rat, murine, porcine, and human bone marrow demonstrate the potential to differentiate into cells with an SMC-like phenotype and function. TGF-beta1 alone or combined with PDGF-BB in serum-free medium induces a temporally correct expression of transcripts and proteins consistent with smooth muscle development. Furthermore, SMCs derived from MAPCs (MAPC-SMCs) demonstrated functional L-type calcium channels. MAPC-SMCs entrapped in fibrin vascular molds became circumferentially aligned and generated force in response to KCl, the L-type channel opener FPL64176, or the SMC agonists 5-HT and ET-1, and exhibited complete relaxation in response to the Rho-kinase inhibitor Y-27632. Cyclic distention (5% circumferential strain) for 3 weeks increased responses by 2- to 3-fold, consistent with what occurred in neonatal SMCs. These results provide evidence that MAPC-SMCs are phenotypically and functionally similar to neonatal SMCs and that the in vitro MAPC-SMC differentiation system may be an ideal model for the study of SMC development. Moreover, MAPC-SMCs may lend themselves to tissue engineering applications.

  6. The effects of denervation, reinnervation, and muscle imbalance on functional muscle length and elbow flexion contracture following neonatal brachial plexus injury.

    Science.gov (United States)

    Weekley, Holly; Nikolaou, Sia; Hu, Liangjun; Eismann, Emily; Wylie, Christopher; Cornwall, Roger

    2012-08-01

    The pathophysiology of paradoxical elbow flexion contractures following neonatal brachial plexus injury (NBPI) is incompletely understood. The current study tests the hypothesis that this contracture occurs by denervation-induced impairment of elbow flexor muscle growth. Unilateral forelimb paralysis was created in mice in four neonatal (5-day-old) BPI groups (C5-6 excision, C5-6 neurotomy, C5-6 neurotomy/repair, and C5-T1 global excision), one non-neonatal BPI group (28-day-old C5-6 excision), and two neonatal muscle imbalance groups (triceps tenotomy ± C5-6 excision). Four weeks post-operatively, motor function, elbow range of motion, and biceps/brachialis functional lengths were assessed. Musculocutaneous nerve (MCN) denervation and reinnervation were assessed immunohistochemically. Elbow flexion motor recovery and elbow flexion contractures varied inversely among the neonatal BPI groups. Contracture severity correlated with biceps/brachialis shortening and MCN denervation (relative axon loss), with no contractures occurring in mice with MCN reinnervation (presence of growth cones). No contractures or biceps/brachialis shortening occurred following non-neonatal BPI, regardless of denervation or reinnervation. Neonatal triceps tenotomy did not cause contractures or biceps/brachialis shortening, nor did it worsen those following neonatal C5-6 excision. Denervation-induced functional shortening of elbow flexor muscles leads to variable elbow flexion contractures depending on the degree, permanence, and timing of denervation, independent of muscle imbalance. Copyright © 2012 Orthopaedic Research Society.

  7. Functional improvement of dystrophic muscle by repression of utrophin: let-7c interaction.

    Directory of Open Access Journals (Sweden)

    Manoj K Mishra

    Full Text Available Duchenne muscular dystrophy (DMD is a fatal genetic disease caused by an absence of the 427kD muscle-specific dystrophin isoform. Utrophin is the autosomal homolog of dystrophin and when overexpressed, can compensate for the absence of dystrophin and rescue the dystrophic phenotype of the mdx mouse model of DMD. Utrophin is subject to miRNA mediated repression by several miRNAs including let-7c. Inhibition of utrophin: let-7c interaction is predicted to 'repress the repression' and increase utrophin expression. We developed and tested the ability of an oligonucleotide, composed of 2'-O-methyl modified bases on a phosphorothioate backbone, to anneal to the utrophin 3'UTR and prevent let-7c miRNA binding, thereby upregulating utrophin expression and improving the dystrophic phenotype in vivo. Suppression of utrophin: let-7c interaction using bi-weekly intraperitoneal injections of let7 site blocking oligonucleotides (SBOs for 1 month in the mdx mouse model for DMD, led to increased utrophin expression along with improved muscle histology, decreased fibrosis and increased specific force. The functional improvement of dystrophic muscle achieved using let7-SBOs suggests a novel utrophin upregulation-based therapeutic strategy for DMD.

  8. The Popeye Domain Containing Genes and Their Function in Striated Muscle

    Science.gov (United States)

    Schindler, Roland F. R.; Scotton, Chiara; French, Vanessa; Ferlini, Alessandra; Brand, Thomas

    2016-01-01

    The Popeye domain containing (POPDC) genes encode a novel class of cAMP effector proteins, which are abundantly expressed in heart and skeletal muscle. Here, we will review their role in striated muscle as deduced from work in cell and animal models and the recent analysis of patients carrying a missense mutation in POPDC1. Evidence suggests that POPDC proteins control membrane trafficking of interacting proteins. Furthermore, we will discuss the current catalogue of established protein-protein interactions. In recent years, the number of POPDC-interacting proteins has been rising and currently includes ion channels (TREK-1), sarcolemma-associated proteins serving functions in mechanical stability (dystrophin), compartmentalization (caveolin 3), scaffolding (ZO-1), trafficking (NDRG4, VAMP2/3) and repair (dysferlin) or acting as a guanine nucleotide exchange factor for Rho-family GTPases (GEFT). Recent evidence suggests that POPDC proteins might also control the cellular level of the nuclear proto-oncoprotein c-Myc. These data suggest that this family of cAMP-binding proteins probably serves multiple roles in striated muscle. PMID:27347491

  9. Cutaneous Feedback of Fingertip Deformation and Vibration for Palpation in Robotic Surgery.

    Science.gov (United States)

    Pacchierotti, Claudio; Prattichizzo, Domenico; Kuchenbecker, Katherine J

    2016-02-01

    Despite its expected clinical benefits, current teleoperated surgical robots do not provide the surgeon with haptic feedback largely because grounded forces can destabilize the system's closed-loop controller. This paper presents an alternative approach that enables the surgeon to feel fingertip contact deformations and vibrations while guaranteeing the teleoperator's stability. We implemented our cutaneous feedback solution on an Intuitive Surgical da Vinci Standard robot by mounting a SynTouch BioTac tactile sensor to the distal end of a surgical instrument and a custom cutaneous display to the corresponding master controller. As the user probes the remote environment, the contact deformations, dc pressure, and ac pressure (vibrations) sensed by the BioTac are directly mapped to input commands for the cutaneous device's motors using a model-free algorithm based on look-up tables. The cutaneous display continually moves, tilts, and vibrates a flat plate at the operator's fingertip to optimally reproduce the tactile sensations experienced by the BioTac. We tested the proposed approach by having eighteen subjects use the augmented da Vinci robot to palpate a heart model with no haptic feedback, only deformation feedback, and deformation plus vibration feedback. Fingertip deformation feedback significantly improved palpation performance by reducing the task completion time, the pressure exerted on the heart model, and the subject's absolute error in detecting the orientation of the embedded plastic stick. Vibration feedback significantly improved palpation performance only for the seven subjects who dragged the BioTac across the model, rather than pressing straight into it.

  10. Accuracy of panoramic, panoramic with palpation and tube shift technique to localize maxillary impacted cuspid

    Directory of Open Access Journals (Sweden)

    GoodarziPour D.

    2009-12-01

    Full Text Available "nBackground and Aim: Impaction of maxillary cuspids is the most common after third molars with 1% to 3% prevalence. Localization of these impacted teeth may affect orthodontic or surgical treatment plan. Therefore, different techniques have been introduced to localize impacted canines. The present study was conducted to compare the accuracy of panoramic, tube shift and panoramic plus palpation in determination of the position of maxillary impacted canine."nMaterials and Methods: 47 patients (20 females, 27 males with the age of more than 12 years (mean age of 25.4 years old whom referred to Dental School, Tehran University of Medical Sciences, with at least one impacted maxillary canine included. An oral and maxillofacial radiologist localized impacted canine first by using panoramic then tube shift technique blindly. After that, an oral and maxillofacial surgeon localized the canine by panoramic and palpation of the area before surgery. Data obtained from radiologist and surgeon were compared with true location of canine after surgery. Statistical analysis was done using sensitivity and specificity."nResults: Among total 47 impacted maxillary canines, 11 cases (23.4% showed buccal impactions and 36 cases (76.6% palatal impactions. Sensitivity (ability of technique to localize palatal impaction of all of the techniques were same (100% but specificity (ability of technique to localize buccal impaction of tube shift (100% was more than two others (0%."nConclusion: The tube shift technique was the most accurate technique to localize maxillary unerupted canines compared to the others. Due to the ability of panoramic and panoramic with palpation in prediction of palatal canine impactions and failure of these techniques to predict buccal impactions, both methods are not suitable in localization of impacted maxillary canines and they must be used as adjunctive techniques.

  11. Test-retest reliability of maximal leg muscle power and functional performance measures in patients with severe osteoarthritis (OA)

    DEFF Research Database (Denmark)

    Villadsen, Allan; Roos, Ewa M.; Overgaard, Søren

    Abstract : Purpose To evaluate the reliability of single-joint and multi-joint maximal leg muscle power and functional performance measures in patients with severe OA. Background Muscle power, taking both strength and velocity into account, is a more functional measure of lower extremity muscle...... and scheduled for unilateral total hip (n=9) or knee (n=11) replacement. Patients underwent a test battery on two occasions separated by approximately one week (range 7 to 11 days). Muscle power was measured using: 1. A linear encoder, unilateral lower limb isolated single-joint dynamic movement, e.g. knee...... flexion 2. A leg extension press, unilateral multi-joint knee and hip extension Functional performance was measured using: 1. 20 m walk usual pace 2. 20 m walk maximal pace 3. 5 times chair stands 4. Maximal number of knee bends/30sec Pain was measured on a VAS prior to and after conducting the entire...

  12. Advanced quantitative methods in correlating sarcopenic muscle degeneration with lower extremity function biometrics and comorbidities.

    Science.gov (United States)

    Edmunds, Kyle; Gíslason, Magnús; Sigurðsson, Sigurður; Guðnason, Vilmundur; Harris, Tamara; Carraro, Ugo; Gargiulo, Paolo

    2018-01-01

    Sarcopenic muscular degeneration has been consistently identified as an independent risk factor for mortality in aging populations. Recent investigations have realized the quantitative potential of computed tomography (CT) image analysis to describe skeletal muscle volume and composition; however, the optimum approach to assessing these data remains debated. Current literature reports average Hounsfield unit (HU) values and/or segmented soft tissue cross-sectional areas to investigate muscle quality. However, standardized methods for CT analyses and their utility as a comorbidity index remain undefined, and no existing studies compare these methods to the assessment of entire radiodensitometric distributions. The primary aim of this study was to present a comparison of nonlinear trimodal regression analysis (NTRA) parameters of entire radiodensitometric muscle distributions against extant CT metrics and their correlation with lower extremity function (LEF) biometrics (normal/fast gait speed, timed up-and-go, and isometric leg strength) and biochemical and nutritional parameters, such as total solubilized cholesterol (SCHOL) and body mass index (BMI). Data were obtained from 3,162 subjects, aged 66-96 years, from the population-based AGES-Reykjavik Study. 1-D k-means clustering was employed to discretize each biometric and comorbidity dataset into twelve subpopulations, in accordance with Sturges' Formula for Class Selection. Dataset linear regressions were performed against eleven NTRA distribution parameters and standard CT analyses (fat/muscle cross-sectional area and average HU value). Parameters from NTRA and CT standards were analogously assembled by age and sex. Analysis of specific NTRA parameters with standard CT results showed linear correlation coefficients greater than 0.85, but multiple regression analysis of correlative NTRA parameters yielded a correlation coefficient of 0.99 (Pbiometrics, SCHOL, and BMI, and particularly highlight the value of the

  13. Relationships between Isometric Muscle Strength, Gait Parameters, and Gross Motor Function Measure in Patients with Cerebral Palsy.

    Science.gov (United States)

    Shin, Hyung Ik; Sung, Ki Hyuk; Chung, Chin Youb; Lee, Kyoung Min; Lee, Seung Yeol; Lee, In Hyeok; Park, Moon Seok

    2016-01-01

    This study investigated the correlation between isometric muscle strength, gross motor function, and gait parameters in patients with spastic cerebral palsy and to find which muscle groups play an important role for gait pattern in a flexed knee gait. Twenty-four ambulatory patients (mean age, 10.0 years) with spastic cerebral palsy who were scheduled for single event multilevel surgery, including distal hamstring lengthening, were included. Preoperatively, peak isometric muscle strength was measured for the hip flexor, hip extensor, knee flexor, and knee extensor muscle groups using a handheld dynamometer, and three-dimensional (3D) gait analysis and gross motor function measure (GMFM) scoring were also performed. Correlations between peak isometric strength and GMFM, gait kinematics, and gait kinetics were analyzed. Peak isometric muscle strength of all muscle groups was not related to the GMFM score and the gross motor function classification system level. Peak isometric strength of the hip extensor and knee extensor was significantly correlated with the mean pelvic tilt (r=-0.588, p=0.003 and r=-0.436, p=0.033) and maximum pelvic obliquity (r=-0.450, p=0.031 and r=-0.419, p=0.041). There were significant correlations between peak isometric strength of the knee extensor and peak knee extensor moment in early stance (r=0.467, p=0.021) and in terminal stance (r=0.416, p=0.043). There is no correlation between muscle strength and gross motor function. However, this study showed that muscle strength, especially of the extensor muscle group of the hip and knee joints, might play a critical role in gait by stabilizing pelvic motion and decreasing energy consumption in a flexed knee gait.

  14. Aerobic exercise training induces skeletal muscle hypertrophy and age-dependent adaptations in myofiber function in young and older men

    Science.gov (United States)

    Konopka, Adam R.; Undem, Miranda K.; Hinkley, James M.; Minchev, Kiril; Kaminsky, Leonard A.; Trappe, Todd A.; Trappe, Scott

    2012-01-01

    To examine potential age-specific adaptations in skeletal muscle size and myofiber contractile physiology in response to aerobic exercise, seven young (YM; 20 ± 1 yr) and six older men (OM; 74 ± 3 yr) performed 12 wk of cycle ergometer training. Muscle biopsies were obtained from the vastus lateralis to determine size and contractile properties of isolated slow [myosin heavy chain (MHC) I] and fast (MHC IIa) myofibers, MHC composition, and muscle protein concentration. Aerobic capacity was higher (P 0.05) with training. Training reduced (P aerobic capacity are similar between YM and OM, while adaptations in myofiber contractile function showed a general improvement in OM. Training-related increases in MHC I and MHC IIa peak power reveal that skeletal muscle of OM is responsive to aerobic exercise training and further support the use of aerobic exercise for improving cardiovascular and skeletal muscle health in older individuals. PMID:22984247

  15. Immediate effect of manual therapy on respiratory functions and inspiratory muscle strength in patients with COPD

    Directory of Open Access Journals (Sweden)

    Yilmaz Yelvar GD

    2016-06-01

    Full Text Available Gul Deniz Yilmaz Yelvar,1 Yasemin Çirak,2 Yasemin Parlak Demir,3 Murat Dalkilinç,1 Bülent Bozkurt4 1Department of Musculoskeletal Physiotherapy, 2Department of Cardiopulmonary Physiotherapy, 3Department of Neurological Rehabilitation, School of Physiotherapy and Rehabilitation, 4Department of Respiratory Medicine, Faculty of Medicine, Turgut Özal University, Ankara, Turkey Objective: The objective of this study was to investigate the immediate effect of manual therapy (MT on respiratory functions and inspiratory muscle strength in patients with COPD.Participants and methods: Thirty patients with severe COPD (eight females and 22 males; mean age 62.4±6.8 years referred to pulmonary physiotherapy were included in this study. The patients participated in a single session of MT to measure the short-term effects. The lung function was measured using a portable spirometer. An electronic pressure transducer was used to measure respiratory muscle strength. Heart rate, breathing frequency, and oxygen saturation were measured with a pulse oximeter. For fatigue and dyspnea perception, the modified Borg rating of perceived exertion scale was used. All measurements were taken before and immediately after the first MT session. The ease-of-breathing visual analog scale was used for rating patients’ symptoms subjectively during the MT session.Results: There was a significant improvement in the forced expiratory volume in the first second, forced vital capacity, and vital capacity values (P<0.05. The maximal inspiratory pressure and maximal expiratory pressure values increased significantly after MT, compared to the pre-MT session (P<0.05. There was a significant decrease in heart rate, respiratory rate (P<0.05, and dyspnea and fatigue perception (P<0.05.Conclusion: A single MT session immediately improved pulmonary function, inspiratory muscle strength, and oxygen saturation and reduced dyspnea, fatigue, and heart and respiratory rates in patients with

  16. Muscle function and body composition profile in adolescents with restrictive anorexia nervosa: Does resistance training help?

    OpenAIRE

    Fernández del Valle, María; Larumbe Zabala, Eneko; Morandé Lavín, Gonzalo; Pérez Ruiz, Margarita

    2016-01-01

    The aim of this study was to analyze the effects of short-term resistance training on the body composition profile and muscle function in a group of Anorexia Nervosa restricting type (AN-R) patients. The sample consisted of AN-R female adolescents (12.8 ± 0.6 years) allocated into the control and intervention groups (n¼18 each). Body composition and relative strength were assessed at baseline, after 8 weeks and 4 weeks following the intervention. Body mass index (BMI) increased throughout...

  17. Effects of Nandrolone in the Counteraction of Skeletal Muscle Atrophy in a Mouse Model of Muscle Disuse: Molecular Biology and Functional Evaluation.

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    Giulia Maria Camerino

    Full Text Available Muscle disuse produces severe atrophy and a slow-to-fast phenotype transition in the postural Soleus (Sol muscle of rodents. Antioxidants, amino-acids and growth factors were ineffective to ameliorate muscle atrophy. Here we evaluate the effects of nandrolone (ND, an anabolic steroid, on mouse skeletal muscle atrophy induced by hindlimb unloading (HU. Mice were pre-treated for 2-weeks before HU and during the 2-weeks of HU. Muscle weight and total protein content were reduced in HU mice and a restoration of these parameters was found in ND-treated HU mice. The analysis of gene expression by real-time PCR demonstrates an increase of MuRF-1 during HU but minor involvement of other catabolic pathways. However, ND did not affect MuRF-1 expression. The evaluation of anabolic pathways showed no change in mTOR and eIF2-kinase mRNA expression, but the protein expression of the eukaryotic initiation factor eIF2 was reduced during HU and restored by ND. Moreover we found an involvement of regenerative pathways, since the increase of MyoD observed after HU suggests the promotion of myogenic stem cell differentiation in response to atrophy. At the same time, Notch-1 expression was down-regulated. Interestingly, the ND treatment prevented changes in MyoD and Notch-1 expression. On the contrary, there was no evidence for an effect of ND on the change of muscle phenotype induced by HU, since no effect of treatment was observed on the resting gCl, restCa and contractile properties in Sol muscle. Accordingly, PGC1α and myosin heavy chain expression, indexes of the phenotype transition, were not restored in ND-treated HU mice. We hypothesize that ND is unable to directly affect the phenotype transition when the specialized motor unit firing pattern of stimulation is lacking. Nevertheless, through stimulation of protein synthesis, ND preserves protein content and muscle weight, which may result advantageous to the affected skeletal muscle for functional recovery.

  18. Soy Glycinin Contains a Functional Inhibitory Sequence against Muscle-Atrophy-Associated Ubiquitin Ligase Cbl-b

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    Tomoki Abe

    2013-01-01

    Full Text Available Background. Unloading stress induces skeletal muscle atrophy. We have reported that Cbl-b ubiquitin ligase is a master regulator of unloading-associated muscle atrophy. The present study was designed to elucidate whether dietary soy glycinin protein prevents denervation-mediated muscle atrophy, based on the presence of inhibitory peptides against Cbl-b ubiquitin ligase in soy glycinin protein. Methods. Mice were fed either 20% casein diet, 20% soy protein isolate diet, 10% glycinin diet containing 10% casein, or 20% glycinin diet. One week later, the right sciatic nerve was cut. The wet weight, cross sectional area (CSA, IGF-1 signaling, and atrogene expression in hindlimb muscles were examined at 1, 3, 3.5, or 4 days after denervation. Results. 20% soy glycinin diet significantly prevented denervation-induced decreases in muscle wet weight and myofiber CSA. Furthermore, dietary soy protein inhibited denervation-induced ubiquitination and degradation of IRS-1 in tibialis anterior muscle. Dietary soy glycinin partially suppressed the denervation-mediated expression of atrogenes, such as MAFbx/atrogin-1 and MuRF-1, through the protection of IGF-1 signaling estimated by phosphorylation of Akt-1. Conclusions. Soy glycinin contains a functional inhibitory sequence against muscle-atrophy-associated ubiquitin ligase Cbl-b. Dietary soy glycinin protein significantly prevented muscle atrophy after denervation in mice.

  19. Improved muscle function and quality after diet intervention with leucine-enriched whey and antioxidants in antioxidant deficient aged mice.

    Science.gov (United States)

    van Dijk, Miriam; Dijk, Francina J; Bunschoten, Annelies; van Dartel, Dorien A M; van Norren, Klaske; Walrand, Stephane; Jourdan, Marion; Verlaan, Sjors; Luiking, Yvette

    2016-04-05

    Antioxidant (AOX) deficiencies are commonly observed in older adults and oxidative stress has been suggested to contribute to sarcopenia. Here we investigate if 1) low levels of dietary antioxidants had a negative impact on parameters of muscle mass, function and quality, and 2) to study if nutritional interventions with AOX and/or leucine-enriched whey protein could improve these muscle parameters in aged mice. 18-months-old mice were fed a casein-based antioxidant-deficient (lowox) diet or a casein-based control-diet (CTRL) for 7 months. During the last 3 months, lowox-mice were subjected to either: a) continued lowox, b) supplementation with vitamin A/E, Selenium and Zinc (AOX), c) substitution of casein with leucine-enriched whey protein (PROT) or d) a combination of both AOX and PROT (TOTAL). After 7 months lowox-mice displayed lower muscle strength and more muscle fatigue compared to CTRL. Compared to lowox-mice, PROT-mice showed improved muscle power, grip strength and less muscle fatigue. AOX-mice showed improved oxidative status, less muscle fatigue, improved grip strength and mitochondrial dynamics compared to lowox-mice. The TOTAL-mice showed the combined effects of both interventions compared to lowox-mice. In conclusion, nutritional intervention with AOX and/or leucine-enriched whey protein can play a role in improving muscle health in a AOX-deficient mouse model.

  20. Impact of Weight Loss on Physical Function with Changes in Strength, Muscle Mass, and Muscle Fat Infiltration in Overweight to Moderately Obese Older Adults: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Adam J. Santanasto

    2011-01-01

    Full Text Available Purpose. Evaluate the effects of weight loss on muscle mass and area, muscle fat infiltration, strength, and their association with physical function. Methods. Thirty-six overweight to moderately obese, sedentary older adults were randomized into either a physical activity plus weight loss (PA+WL or physical activity plus successful aging health education (PA+SA program. Measurements included body composition by dual-energy X-ray absorptiometry, computerized tomography, knee extensor strength, and short physical performance battery (SPPB. Results. At 6 months, PA+WL lost greater thigh fat and muscle area compared to PA+SA. PA+WL lost 12.4% strength; PA+SA lost 1.0%. Muscle fat infiltration decreased significantly in PA+WL and PA+SA. Thigh fat area decreased 6-fold in comparison to lean area in PA+WL. Change in total SPPB score was strongly inversely correlated with change in fat but not with change in lean or strength. Conclusion. Weight loss resulted in additional improvements in function over exercise alone, primarily due to loss of body fat.

  1. Deletion of the transcriptional coactivator PGC1α in skeletal muscles is associated with reduced expression of genes related to oxidative muscle function

    International Nuclear Information System (INIS)

    Hatazawa, Yukino; Minami, Kimiko; Yoshimura, Ryoji; Onishi, Takumi; Manio, Mark Christian; Inoue, Kazuo; Sawada, Naoki; Suzuki, Osamu; Miura, Shinji; Kamei, Yasutomi

    2016-01-01

    The expression of the transcriptional coactivator PGC1α is increased in skeletal muscles during exercise. Previously, we showed that increased PGC1α leads to prolonged exercise performance (the duration for which running can be continued) and, at the same time, increases the expression of branched-chain amino acid (BCAA) metabolism-related enzymes and genes that are involved in supplying substrates for the TCA cycle. We recently created mice with PGC1α knockout specifically in the skeletal muscles (PGC1α KO mice), which show decreased mitochondrial content. In this study, global gene expression (microarray) analysis was performed in the skeletal muscles of PGC1α KO mice compared with that of wild-type control mice. As a result, decreased expression of genes involved in the TCA cycle, oxidative phosphorylation, and BCAA metabolism were observed. Compared with previously obtained microarray data on PGC1α-overexpressing transgenic mice, each gene showed the completely opposite direction of expression change. Bioinformatic analysis of the promoter region of genes with decreased expression in PGC1α KO mice predicted the involvement of several transcription factors, including a nuclear receptor, ERR, in their regulation. As PGC1α KO microarray data in this study show opposing findings to the PGC1α transgenic data, a loss-of-function experiment, as well as a gain-of-function experiment, revealed PGC1α’s function in the oxidative energy metabolism of skeletal muscles. - Highlights: • Microarray analysis was performed in the skeletal muscle of PGC1α KO mice. • Expression of genes in the oxidative energy metabolism was decreased. • Bioinformatic analysis of promoter region of the genes predicted involvement of ERR. • PGC1α KO microarray data in this study show the mirror image of transgenic data.

  2. Independent and Combined Effects of Exercise and Vitamin D on Muscle Morphology, Function and Falls in the Elderly

    Directory of Open Access Journals (Sweden)

    Robin M. Daly

    2010-09-01

    Full Text Available Regular exercise, particularly progressive resistance training (PRT, is recognized as one of the most effective strategies to prevent age-related muscle loss (sarcopenia, but its effects on muscle function are mixed. However, emerging data indicates that high velocity PRT (fast concentric muscle contractions is more effective for improving functional outcomes than traditional PRT. In terms of falls prevention, high-challenging balance training programs appear to be most effective. There is also compelling evidence that supplemental vitamin D is an effective therapeutic option for falls prevention. The findings from a recent meta-analysis revealed that supplemental vitamin D at a dose of at least 700–1,000 IU/d or an achieved serum 25(OHD level of at least 60 nmol/L was associated with reduced falls risk among older individuals. Based on these findings, it is possible that the combination of exercise and vitamin D could have a synergistic effect on muscle morphology and function, particularly since both interventions have been shown to have beneficial effects on type II “fast twitch” muscle fibers and systemic inflammation, which have both been linked to losses in muscle mass and function. Unfortunately however, the findings from the limited number of factorial 2 × 2 design RCTs indicate that additional vitamin D does not enhance the effects of exercise on measures of muscle morphology, function or falls risk. However, none of these trials were adequately powered to detect a “synergistic” effect between the two treatment strategies, but it is likely that if an exercise-by-vitamin D interaction does exist, it may be limited to situations when vitamin D deficiency/insufficiency is corrected. Further targeted research in “high risk” groups is still needed to address this question, and evaluate whether there is a threshold level of serum 25(OHD to maximize the effects of exercise on muscle and falls risk.

  3. Disruption of ATP-sensitive potassium channel function in skeletal muscles promotes production and secretion of musclin

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, Ana, E-mail: ana-sierra@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Subbotina, Ekaterina, E-mail: ekaterina-subbotina@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Zhu, Zhiyong, E-mail: zhiyong-zhu@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Gao, Zhan, E-mail: zhan-gao@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Koganti, Siva Rama Krishna, E-mail: sivaramakrishna.koganti@ttuhc.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Coetzee, William A., E-mail: william.coetzee@nyumc.org [Department of Pediatrics, NYU School of Medicine, New York, NY 10016 (United States); Goldhamer, David J., E-mail: david.goldhamer@uconn.edu [Center for Regenerative Biology, Department of Molecular and Cell Biology, Advanced Technology Laboratory, University of Connecticut, 1392 Storrs Road Unit 4243, Storrs, Connecticut 06269 (United States); Hodgson-Zingman, Denice M., E-mail: denice-zingman@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, Iowa City, IA 52242 (United States); Zingman, Leonid V., E-mail: leonid-zingman@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, Iowa City, IA 52242 (United States); Department of Veterans Affairs, Medical Center, Iowa City, IA 52242 (United States)

    2016-02-26

    Sarcolemmal ATP-sensitive potassium (K{sub ATP}) channels control skeletal muscle energy use through their ability to adjust membrane excitability and related cell functions in accordance with cellular metabolic status. Mice with disrupted skeletal muscle K{sub ATP} channels exhibit reduced adipocyte size and increased fatty acid release into the circulation. As yet, the molecular mechanisms underlying this link between skeletal muscle K{sub ATP} channel function and adipose mobilization have not been established. Here, we demonstrate that skeletal muscle-specific disruption of K{sub ATP} channel function in transgenic (TG) mice promotes production and secretion of musclin. Musclin is a myokine with high homology to atrial natriuretic peptide (ANP) that enhances ANP signaling by competing for elimination. Augmented musclin production in TG mice is driven by a molecular cascade resulting in enhanced acetylation and nuclear exclusion of the transcription factor forkhead box O1 (FOXO1) – an inhibitor of transcription of the musclin encoding gene. Musclin production/secretion in TG is paired with increased mobilization of fatty acids and a clear trend toward increased circulating ANP, an activator of lipolysis. These data establish K{sub ATP} channel-dependent musclin production as a potential mechanistic link coupling “local” skeletal muscle energy consumption with mobilization of bodily resources from fat. Understanding such mechanisms is an important step toward designing interventions to manage metabolic disorders including those related to excess body fat and associated co-morbidities. - Highlights: • ATP-sensitive K{sup +} channels regulate musclin production by skeletal muscles. • Lipolytic ANP signaling is promoted by augmented skeletal muscle musclin production. • Skeletal muscle musclin transcription is promoted by a CaMKII/HDAC/FOXO1 pathway. • Musclin links adipose mobilization to energy use in K{sub ATP} channel deficient skeletal muscle.

  4. Disruption of ATP-sensitive potassium channel function in skeletal muscles promotes production and secretion of musclin

    International Nuclear Information System (INIS)

    Sierra, Ana; Subbotina, Ekaterina; Zhu, Zhiyong; Gao, Zhan; Koganti, Siva Rama Krishna; Coetzee, William A.; Goldhamer, David J.; Hodgson-Zingman, Denice M.; Zingman, Leonid V.

    2016-01-01

    Sarcolemmal ATP-sensitive potassium (K_A_T_P) channels control skeletal muscle energy use through their ability to adjust membrane excitability and related cell functions in accordance with cellular metabolic status. Mice with disrupted skeletal muscle K_A_T_P channels exhibit reduced adipocyte size and increased fatty acid release into the circulation. As yet, the molecular mechanisms underlying this link between skeletal muscle K_A_T_P channel function and adipose mobilization have not been established. Here, we demonstrate that skeletal muscle-specific disruption of K_A_T_P channel function in transgenic (TG) mice promotes production and secretion of musclin. Musclin is a myokine with high homology to atrial natriuretic peptide (ANP) that enhances ANP signaling by competing for elimination. Augmented musclin production in TG mice is driven by a molecular cascade resulting in enhanced acetylation and nuclear exclusion of the transcription factor forkhead box O1 (FOXO1) – an inhibitor of transcription of the musclin encoding gene. Musclin production/secretion in TG is paired with increased mobilization of fatty acids and a clear trend toward increased circulating ANP, an activator of lipolysis. These data establish K_A_T_P channel-dependent musclin production as a potential mechanistic link coupling “local” skeletal muscle energy consumption with mobilization of bodily resources from fat. Understanding such mechanisms is an important step toward designing interventions to manage metabolic disorders including those related to excess body fat and associated co-morbidities. - Highlights: • ATP-sensitive K"+ channels regulate musclin production by skeletal muscles. • Lipolytic ANP signaling is promoted by augmented skeletal muscle musclin production. • Skeletal muscle musclin transcription is promoted by a CaMKII/HDAC/FOXO1 pathway. • Musclin links adipose mobilization to energy use in K_A_T_P channel deficient skeletal muscle.

  5. Prostaglandin E2 is essential for efficacious skeletal muscle stem-cell function, augmenting regeneration and strength.

    Science.gov (United States)

    Ho, Andrew T V; Palla, Adelaida R; Blake, Matthew R; Yucel, Nora D; Wang, Yu Xin; Magnusson, Klas E G; Holbrook, Colin A; Kraft, Peggy E; Delp, Scott L; Blau, Helen M

    2017-06-27

    Skeletal muscles harbor quiescent muscle-specific stem cells (MuSCs) capable of tissue regeneration throughout life. Muscle injury precipitates a complex inflammatory response in which a multiplicity of cell types, cytokines, and growth factors participate. Here we show that Prostaglandin E2 (PGE2) is an inflammatory cytokine that directly targets MuSCs via the EP4 receptor, leading to MuSC expansion. An acute treatment with PGE2 suffices to robustly augment muscle regeneration by either endogenous or transplanted MuSCs. Loss of PGE2 signaling by specific genetic ablation of the EP4 receptor in MuSCs impairs regeneration, leading to decreased muscle force. Inhibition of PGE2 production through nonsteroidal anti-inflammatory drug (NSAID) administration just after injury similarly hinders regeneration and compromises muscle strength. Mechanistically, the PGE2 EP4 interaction causes MuSC expansion by triggering a cAMP/phosphoCREB pathway that activates the proliferation-inducing transcription factor, Nurr1 Our findings reveal that loss of PGE2 signaling to MuSCs during recovery from injury impedes muscle repair and strength. Through such gain- or loss-of-function experiments, we found that PGE2 signaling acts as a rheostat for muscle stem-cell function. Decreased PGE2 signaling due to NSAIDs or increased PGE2 due to exogenous delivery dictates MuSC function, which determines the outcome of regeneration. The markedly enhanced and accelerated repair of damaged muscles following intramuscular delivery of PGE2 suggests a previously unrecognized indication for this therapeutic agent.

  6. Effect of traditional resistance and power training using rated perceived exertion for enhancement of muscle strength, power, and functional performance.

    Science.gov (United States)

    Tiggemann, Carlos Leandro; Dias, Caroline Pieta; Radaelli, Regis; Massa, Jéssica Cassales; Bortoluzzi, Rafael; Schoenell, Maira Cristina Wolf; Noll, Matias; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins

    2016-04-01

    The present study compared the effects of 12 weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75 years) were randomly assigned to traditional resistance training group (TRT; n = 15) or power training group (PT; n = 15). Participants trained twice a week for 12 weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58 %) and knee extension (≈20 %) increased significantly (p training. Muscle power also increased with training (≈27 %; p functional performance after training period (≈13 %; p effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.

  7. Timed function tests, motor function measure, and quantitative thigh muscle MRI in ambulant children with Duchenne muscular dystrophy: A cross-sectional analysis.

    Science.gov (United States)

    Schmidt, Simone; Hafner, Patricia; Klein, Andrea; Rubino-Nacht, Daniela; Gocheva, Vanya; Schroeder, Jonas; Naduvilekoot Devasia, Arjith; Zuesli, Stephanie; Bernert, Guenther; Laugel, Vincent; Bloetzer, Clemens; Steinlin, Maja; Capone, Andrea; Gloor, Monika; Tobler, Patrick; Haas, Tanja; Bieri, Oliver; Zumbrunn, Thomas; Fischer, Dirk; Bonati, Ulrike

    2018-01-01

    The development of new therapeutic agents for the treatment of Duchenne muscular dystrophy has put a focus on defining outcome measures most sensitive to capture treatment effects. This cross-sectional analysis investigates the relation between validated clinical assessments such as the 6-minute walk test, motor function measure and quantitative muscle MRI of thigh muscles in ambulant Duchenne muscular dystrophy patients, aged 6.5 to 10.8 years (mean 8.2, SD 1.1). Quantitative muscle MRI included the mean fat fraction using a 2-point Dixon technique, and transverse relaxation time (T2) measurements. All clinical assessments were highly significantly inter-correlated with p muscle MRI values significantly correlated with all clinical assessments with the extensors showing the strongest correlation. In contrast to the clinical assessments, quantitative muscle MRI values were highly significantly correlated with age. In conclusion, the motor function measure and timed function tests measure disease severity in a highly comparable fashion and all tests correlated with quantitative muscle MRI values quantifying fatty muscle degeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. THE COMPARISON OF THE LUMBAR MULTIFIDUS MUSCLES FUNCTION BETWEEN GYMNASTIC ATHLETES WITH SWAY-BACK POSTURE AND NORMAL POSTURE.

    Science.gov (United States)

    Mahdavie, Elnaz; Rezasoltani, Asghar; Simorgh, Leila

    2017-08-01

    The prevalence of sway back posture (SBP) is very high among elite gymnasts. This posture may be partly due to the improper function of lumbar multifidus muscles (LMM) as lumbar stabilizers muscles. The aim of this study was to compare the thicknesses of LMM measured at rest and during the contraction elicited during an arm lift between elite gymnasts with SBP and normal posture. Observational, descriptive, comparative. The participants consist of twenty gymnasts between the ages of 17 and 30 who had trained in gymnastics for more than ten years. They were assigned to two groups: SBP (n=10) and control (n=10). Posture analysis with grid paper and plumb line was performed for all subjects. The thickness of LMM on dominant side of spinal column was measured by a real-time ultrasound at five lumbar levels. The thickness of the LMM was measured both at rest and during the contraction elicited during an arm lift. The variation between the LMM thickness between the muscle at rest and muscle at the peak of contraction was regarded as LMM muscle function. The thickness of LMM was less in SBP group than the control group at all lumbar segments. The variation in LMM thickness between the state of rest and muscle contraction was significantly less in athletes with SBP than controls when compared at all levels of the lumbar spine (p antigravity and stabilizing muscle group was decreased during arm raising in gymnasts with SBP. 3a.

  9. Naked mole-rats maintain healthy skeletal muscle and Complex IV mitochondrial enzyme function into old age.

    Science.gov (United States)

    Stoll, Elizabeth A; Karapavlovic, Nevena; Rosa, Hannah; Woodmass, Michael; Rygiel, Karolina; White, Kathryn; Turnbull, Douglass M; Faulkes, Chris G

    2016-12-19

    The naked mole-rat (NMR) Heterocephalus glaber is an exceptionally long-lived rodent, living up to 32 years in captivity. This extended lifespan is accompanied by a phenotype of negligible senescence, a phenomenon of very slow changes in the expected physiological characteristics with age. One of the many consequences of normal aging in mammals is the devastating and progressive loss of skeletal muscle, termed sarcopenia, caused in part by respiratory enzyme dysfunction within the mitochondria of skeletal muscle fibers. Here we report that NMRs avoid sarcopenia for decades. Muscle fiber integrity and mitochondrial ultrastructure are largely maintained in aged animals. While mitochondrial Complex IV expression and activity remains stable, Complex I expression is significantly decreased. We show that aged naked mole-rat skeletal muscle tissue contains some mitochondrial DNA rearrangements, although the common mitochondrial DNA deletions associated with aging in human and other rodent skeletal muscles are not present. Interestingly, NMR skeletal muscle fibers demonstrate a significant increase in mitochondrial DNA copy number. These results have intriguing implications for the role of mitochondria in aging, suggesting Complex IV, but not Complex I, function is maintained in the long-lived naked mole rat, where sarcopenia is avoided and healthy muscle function is maintained for decades.

  10. Oxidative stress induces caveolin 1 degradation and impairs caveolae functions in skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Alexis Mougeolle

    Full Text Available Increased level of oxidative stress, a major actor of cellular aging, impairs the regenerative capacity of skeletal muscle and leads to the reduction in the number and size of muscle fibers causing sarcopenia. Caveolin 1 is the major component of caveolae, small membrane invaginations involved in signaling and endocytic trafficking. Their role has recently expanded to mechanosensing and to the regulation of oxidative stress-induced pathways. Here, we increased the amount of reactive oxidative species in myoblasts by addition of hydrogen peroxide (H2O2 at non-toxic concentrations. The expression level of caveolin 1 was significantly decreased as early as 10 min after 500 μM H2O2 treatment. This reduction was not observed in the presence of a proteasome inhibitor, suggesting that caveolin 1 was rapidly degraded by the proteasome. In spite of caveolin 1 decrease, caveolae were still able to assemble at the plasma membrane. Their functions however were significantly perturbed by oxidative stress. Endocytosis of a ceramide analog monitored by flow cytometry was significantly diminished after H2O2 treatment, indicating that oxidative stress impaired its selective internalization via caveolae. The contribution of caveolae to the plasma membrane reservoir has been monitored after osmotic cell swelling. H2O2 treatment increased membrane fragility revealing that treated cells were more sensitive to an acute mechanical stress. Altogether, our results indicate that H2O2 decreased caveolin 1 expression and impaired caveolae functions. These data give new insights on age-related deficiencies in skeletal muscle.

  11. Positive effects of 1-year football and strength training on mechanical muscle function and functional capacity in elderly men

    DEFF Research Database (Denmark)

    Sundstrup, Emil; Jakobsen, Markus Due; Andersen, Lars L.

    2016-01-01

    PURPOSE: A decline in physical capacity takes place with increasing age that negatively affects overall physical function including work ability and the ability to perform typical activities of daily living (ADL). The overall aim of the present study was to determine the neuromuscular adaptations...... to long-term (1 year) football and strength training in older untrained adults, and to assess the concurrent effect on functional ADL capacity. METHODS: Twenty-seven healthy elderly males (68.2 ± 3.2 years) were randomly assigned to 12 months of either recreational football training (FT: n = 10), strength...... training (ST: n = 9) or served as inactive controls (CON: n = 8). Recreational football training consisted of small-sided training sessions whereas strength training consisted of high intensity exercises targeting the lower extremity and upper body. Maximal thigh muscle strength and rate of force...

  12. TRPV1 channels in human skeletal muscle feed arteries: implications for vascular function.

    Science.gov (United States)

    Ives, Stephen J; Park, Song Young; Kwon, Oh Sung; Gifford, Jayson R; Andtbacka, Robert H I; Hyngstrom, John R; Richardson, Russell S

    2017-09-01

    What is the central question of this study? We sought to determine whether human skeletal muscle feed arteries (SFMAs) express TRPV 1 channels and what role they play in modulating vascular function. What is the main finding and its importance? Human SMFAs do express functional TRPV 1 channels that modulate vascular function, specifically opposing α-adrenergic receptor-mediated vasocontraction and potentiating vasorelaxation, in an endothelium-dependent manner, as evidenced by the α 1 -receptor-mediated responses. Thus, the vasodilatory role of TRPV 1 channels, and their ligand capsaicin, could be a potential therapeutic target for improving vascular function. Additionally, given the 'sympatholytic' effect of TRPV 1 activation and known endogenous activators (anandamide, reactive oxygen species, H + , etc.), TRPV 1 channels might contribute to functional sympatholysis during exercise. To examine the role of the transient receptor potential vanilloid type 1 (TRPV 1 ) ion channel in the vascular function of human skeletal muscle feed arteries (SMFAs) and whether activation of this heat-sensitive receptor could be involved in modulating vascular function, SMFAs from 16 humans (63 ± 5 years old, range 41-89 years) were studied using wire myography with capsaicin (TRPV 1 agonist) and without (control). Specifically, phenylephrine (α 1 -adrenergic receptor agonist), dexmedetomidine (α 2 -adrenergic receptor agonist), ACh and sodium nitroprusside concentration-response curves were established to assess the role of TRPV 1 channels in α-receptor-mediated vasocontraction as well as endothelium-dependent and -independent vasorelaxation, respectively. Compared with control conditions, capsaicin significantly attenuated maximal vasocontraction in response to phenylephrine [control, 52 ± 8% length-tension max (LT max ) and capsaicin, 21 ± 5%LT max ] and dexmedetomidine (control, 29 ± 12%LT max and capsaicin, 2 ± 3%LT max ), while robustly enhancing maximal

  13. Palpation imaging using a haptic system for virtual reality applications in medicine.

    Science.gov (United States)

    Khaled, W; Reichling, S; Bruhns, O T; Boese, H; Baumann, M; Monkman, G; Egersdoerfer, S; Klein, D; Tunayar, A; Freimuth, H; Lorenz, A; Pessavento, A; Ermert, H

    2004-01-01

    In the field of medical diagnosis, there is a strong need to determine mechanical properties of biological tissue, which are of histological and pathological relevance. Malignant tumors are significantly stiffer than surrounding healthy tissue. One of the established diagnosis procedures is the palpation of body organs and tissue. Palpation is used to measure swelling, detect bone fracture, find and measure pulse, or to locate changes in the pathological state of tissue and organs. Current medical practice routinely uses sophisticated diagnostic tests through magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) imaging. However, they cannot provide direct measure of tissue elasticity. Last year we presented the concept of the first haptic sensor actuator system to visualize and reconstruct mechanical properties of tissue using ultrasonic elastography and a haptic display with electrorheological fluids. We developed a real time strain imaging system for tumor diagnosis. It allows biopsies simultaneously to conventional ultrasound B-Mode and strain imaging investigations. We deduce the relative mechanical properties by using finite element simulations and numerical solution models solving the inverse problem. Various modifications on the haptic sensor actuator system have been investigated. This haptic system has the potential of inducing real time substantial forces, using a compact lightweight mechanism which can be applied to numerous areas including intraoperative navigation, telemedicine, teaching and telecommunication.

  14. Experimental evaluation of magnified haptic feedback for robot-assisted needle insertion and palpation.

    Science.gov (United States)

    Meli, Leonardo; Pacchierotti, Claudio; Prattichizzo, Domenico

    2017-12-01

    Haptic feedback has been proven to play a key role in enhancing the performance of teleoperated medical procedures. However, due to safety issues, commercially-available medical robots do not currently provide the clinician with haptic feedback. This work presents the experimental evaluation of a teleoperation system for robot-assisted medical procedures able to provide magnified haptic feedback to the clinician. Forces registered at the operating table are magnified and provided to the clinician through a 7-DoF haptic interface. The same interface is also used to control the motion of a 6-DoF slave robotic manipulator. The safety of the system is guaranteed by a time-domain passivity-based control algorithm. Two experiments were carried out on stiffness discrimination (during palpation and needle insertion) and one experiment on needle guidance. Our haptic-enabled teleoperation system improved the performance with respect to direct hand interaction of 80%, 306%, and 27% in stiffness discrimination through palpation, stiffness discrimination during needle insertion, and guidance, respectively. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Variability of the morphology of gastrocnemius muscle in an African ...

    African Journals Online (AJOL)

    ... palpation of popliteal arterial pulse, popliteal nerve block and the assessment of gastrocnemius muscle for autografting. The additional variant heads also bear evolutionary importance. Keywords: Gastrocnemius; Multi-Pinnate; Popliteal Entrapment Syndrome; Variations; Four-Headed, Third Head Of Gastrocnemius ...

  16. Recovery of rat muscle size but not function more than 1 year after a single botulinum toxin injection.

    Science.gov (United States)

    Ward, Samuel R; Minamoto, Viviane B; Suzuki, Kentaro P; Hulst, Jonah B; Bremner, Shannon N; Lieber, Richard L

    2018-03-01

    Neurotoxin injection is used to treat a wide variety of neuromuscular disorders. The purpose of this study was to measure the functional and structural properties of botulinum toxin-injected adult rat skeletal muscle over nearly the entire lifespan. Ten groups of animals were subjected to either neurotoxin injection [Botox, Type A (BT-A); Allergan, Irvine, California] or saline solution injection. Neurotoxin-injected animals (n = 90) were analyzed at different time-points: 1 week; 1 month; 3 months; 6 months; 12 months; or 18 months. In spite of the recovery of structural features, such as muscle mass and fiber area, dorsiflexion torque production remained significantly depressed by 25%, even at 12 months after neurotoxin injection. The data demonstrate that, after a single BT-A injection, although gross muscle morphology recovered over a 12-month time period, loss of contractile function did not recover. Muscle Nerve 57: 435-441, 2018. © 2017 Wiley Periodicals, Inc.

  17. Restoration of heart functions using human embryonic stem cells derived heart muscle cells.

    Science.gov (United States)

    Gepstein, Lior; Kehat, Izhak

    2005-02-01

    Extract: Recent advances in molecular and cellular biology and specifically in the areas of stem cell biology and tissue engineering have paved the way for the development of a new field in biomedicine, regenerative medicine. This exciting approach seeks to develop new biological solutions, using the mobilization of endogenous stem cells or delivery of exogenous cells to replace or modify the function of diseased, absent, or malfunctioning tissue. The adult heart represents an attractive candidate for these emerging technologies, since adult cardiomyocytes have limited regenerative capacity. Thus, any significant heart cell loss or dysfunction, such as occurs during heart attack, is mostly irreversible and may lead to the development of progressive heart failure, one of the leading causes of world-wide morbidity and mortality. Similarly, dysfunction of the specialized electrical conduction system within the heart may result in inefficient rhythm initiation or impulse conduction, leading to significant slowing of the heart rate, usually requiring the implantation of a permanent electronic pacemaker. Replacement of the dysfunctional myocardium (heart muscle) by implantation of external heart muscle cells is emerging as a novel paradigm for restoration of the myocardial electromechanical properties, but has been significantly hampered by the paucity of cell sources for human heart cells and by the relatively limited evidence for functional integration between grafted and host cells. The recently described human embryonic stem cell (hESC) lines may provide a possible solution for the aforementioned cell sourcing problem.

  18. Facial dimensions, bite force and masticatory muscle thickness in preschool children with functional posterior crossbite

    Directory of Open Access Journals (Sweden)

    Paula Midori Castelo

    2008-03-01

    Full Text Available Posterior crossbite may affect craniofacial growth and development. Thus, this study aimed to associate facial dimensions (by standardized frontal photographs to masseter and anterior portion of the temporal muscle thickness (by ultrasonography and maximal bilateral bite force in 49 children with deciduous and early mixed dentitions. They were distributed in four groups: deciduous-normal occlusion (DNO, n = 15, deciduous-crossbite (DCB, n = 10, mixed-normal occlusion (MNO, n = 13 and mixed-crossbite (MCB, n = 11. Anterior facial height (AFH, bizygomatic width (FWB, and intergonial width (FWI were determined and associated with muscle thickness and bite force, applying Pearson’s coefficients and multiple logistic regression, with age, gender, body weight and height as the covariates. FWB and FWI were correlated positively with the masseter thickness, whereas AFH/FWB and AFH/FWI ratios had negative correlation, except in the DNO group. The correlation between AFH/FWB and bite force in the MCB group was significantly negative. A higher AFH/FWB in MNO and MCB led to a significantly higher probability for functional crossbite development. In the studied sample, it was observed that children in the early mixed dentition with a long-face trend showed lower bite force and higher probability to present functional posterior crossbite, without significant influence of the covariates.

  19. The effect of peculiar complex core balance training on isokinetic muscle functions of the knee and lumbus

    OpenAIRE

    Lee, Myungsun; Han, Gunsoo

    2016-01-01

    [Purpose] This study aimed to investigate the effect of peculiar complex core balance training on the isokinetic muscle function of the knee joint and lumbus to provide fundamental data for establishing a training program that focuses on improving the performance and prevention of injury by developing the core and low extremity muscles. [Subjects and Methods] The participants in this study included a total of ten high school athletes involved in a throwing event for over five years. The subje...

  20. Ulk1-mediated autophagy plays an essential role in mitochondrial remodeling and functional regeneration of skeletal muscle.

    Science.gov (United States)

    Call, Jarrod A; Wilson, Rebecca J; Laker, Rhianna C; Zhang, Mei; Kundu, Mondira; Yan, Zhen

    2017-06-01

    Autophagy is a conserved cellular process for degrading aggregate proteins and dysfunctional organelle. It is still debatable if autophagy and mitophagy (a specific process of autophagy of mitochondria) play important roles in myogenic differentiation and functional regeneration of skeletal muscle. We tested the hypothesis that autophagy is critical for functional regeneration of skeletal muscle. We first observed time-dependent increases (3- to 6-fold) of autophagy-related proteins (Atgs), including Ulk1, Beclin1, and LC3, along with reduced p62 expression during C2C12 differentiation, suggesting increased autophagy capacity and flux during myogenic differentiation. We then used cardiotoxin (Ctx) or ischemia-reperfusion (I/R) to induce muscle injury and regeneration and observed increases in Atgs between days 2 and 7 in adult skeletal muscle followed by increased autophagy flux after day 7 Since Ulk1 has been shown to be essential for mitophagy, we asked if Ulk1 is critical for functional regeneration in skeletal muscle. We subjected skeletal muscle-specific Ulk1 knockout mice (MKO) to Ctx or I/R. MKO mice had significantly impaired recovery of muscle strength and mitochondrial protein content post-Ctx or I/R. Imaging analysis showed that MKO mice have significantly attenuated recovery of mitochondrial network at 7 and 14 days post-Ctx. These findings suggest that increased autophagy protein and flux occur during muscle regeneration and Ulk1-mediated mitophagy is critical for recovery for the mitochondrial network and hence functional regeneration. Copyright © 2017 the American Physiological Society.

  1. The functional muscle-bone unit in children with cerebral palsy.

    Science.gov (United States)

    Duran, I; Schütz, F; Hamacher, S; Semler, O; Stark, C; Schulze, J; Rittweger, J; Schoenau, E

    2017-07-01

    Our results suggest that the prevalence of bone health deficits in children with CP was overestimated, when using only age- and height-adjusted bone mineral content (BMC) and areal bone mineral density (aBMD). When applying the functional muscle-bone unit diagnostic algorithm (FMBU-A), the prevalence of positive results decreased significantly. We recommend applying the FMBU-A when assessing bone health in children with CP. The prevalence of bone health deficits in children with cerebral palsy (CP) might be overestimated because age- and height-adjusted reference percentiles for bone mineral content (BMC) and areal bone mineral density (aBMD) assessed by dual-energy X-ray absorptiometry (DXA) do not consider reduced muscle activity. The aim of this study was to compare the prevalence of positive DXA-based indicators for bone health deficits in children with CP to the prevalence of positive findings after applying a functional muscle-bone unit diagnostic algorithm (FMBU-A) considering reduced muscle activity. The present study was a monocentric retrospective analysis of 297 whole body DXA scans of children with CP. The prevalence of positive results of age- and height-adjusted BMC and aBMD defined as BMC and aBMD below the P3 percentile and of the FMBU-A was calculated. In children with CP, the prevalence of positive results of age-adjusted BMC were 33.3% and of aBMD 50.8%. Height-adjusted results for BMC and aBMD were positive in 16.8 and 36.0% of cases. The prevalence of positive results applying the FMBU-A regarding BMC and aBMD were significantly (p BMC and aBMD (8.8 and 14.8%). Our results suggest that the prevalence of bone health deficits in children with CP was overestimated, when using age- and height-adjusted BMC and aBMD. When applying the FMBU-A, the prevalence decreased significantly. We recommend applying the FMBU-A when assessing bone health in children with CP.

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

    Directory of Open Access Journals (Sweden)

    Michael J. Wacker

    2016-05-01

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

  3. Relation between isokinetic muscle strength and functional capacity in recreational athletes with chondromalacia patellae.

    Science.gov (United States)

    Yildiz, Y; Aydin, T; Sekir, U; Cetin, C; Ors, F; Alp Kalyon, T

    2003-12-01

    To investigate the effects of isokinetic exercise on pain and functional test scores of recreational athletes with chondromalacia patellae (CMP) and to examine the correlation between isokinetic parameters and functional tests or pain score. The functional ability of 30 recreational athletes with unilateral CMP was evaluated using six different tests. Pain scores were assessed during daily activities before and after the treatment protocol. Isokinetic exercise sessions were carried out at angular velocities of 60 degrees /s (25-90 degrees range of flexion) and 180 degrees /s (full range). These sessions were repeated three times a week for six weeks. Quadriceps and hamstring peak torque, total work, and endurance ratios had improved significantly after the treatment, as did the functional parameters and pain scores. There was a poor correlation between the extensor endurance ratio and one leg standing test. A moderate correlation between the visual analogue scale and the extensor endurance ratio or flexion endurance ratio was also found. The isokinetic exercise programme used in this study had a positive effect on muscle strength, pain score, and functional ability of knees with CMP. The improvement in the functional capacity did not correlate with the isokinetic parameters.

  4. Tendinitis of the Temporalis muscle: Differential diagnosis and treatment. A Case Report.

    Directory of Open Access Journals (Sweden)

    Veronica Iturriaga.

    2016-03-01

    Full Text Available Introduction: The temporalis muscle plays an essential role in mastication and is actively involved in the mandibular closing movement. It is covered by a fibroelastic fascia that forms its tendon. Tendinitis is a degenerative and inflammatory process, which originates in the tendon-bone junction. Signs and symptoms such as swelling, pain, tenderness on palpation, limitation of movement and mouth opening are frequently associated with other temporomandibular disorders and not with tendinitis as a causal factor. Objective: To describe a clinical case identifying the diagnostic process and management of tendinitis of the temporalis muscle. Case report: A 30-year old male patient who sought treatment after continuous squeezing pain in the zygomatic and bilateral temporal regions with increased pain during mouth opening and mandibular function. The patient referred pain in the insertion region of the tendon of the temporalis muscle. Pain was removed after using anesthesia, consequently confirming the diagnosis of tendinitis of the temporalis muscle. Primary management measures were performed and then peritendinous corticosteroids were administered. The patient did not refer spontaneous or functional pain during check-up. Conclusion: Tendinitis of the temporalis muscle is a common condition, although frequently underdiagnosed. A good differential diagnosis must be performed to avoid confusion with other common conditions such as odontogenic pain, sinusitis, arthralgia, myofascial pain and migraine. Management depends on the type of tendinitis. It usually occurs in conjunction with other types of TMD or facial pain, so it is important to know the different clinical characteristics of pathologies with similar manifestations.

  5. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Viitanen, Matti; Sundström, Erik; Baumann, Marc; Poyhonen, Minna; Tikka, Saara; Behbahani, Homira

    2013-01-01

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψ m ) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  6. Role of dystrophin in airway smooth muscle phenotype, contraction and lung function.

    Directory of Open Access Journals (Sweden)

    Pawan Sharma

    Full Text Available Dystrophin links the transmembrane dystrophin-glycoprotein complex to the actin cytoskeleton. We have shown that dystrophin-glycoprotein complex subunits are markers for airway smooth muscle phenotype maturation and together with caveolin-1, play an important role in calcium homeostasis. We tested if dystrophin affects phenotype maturation, tracheal contraction and lung physiology. We used dystrophin deficient Golden Retriever dogs (GRMD and mdx mice vs healthy control animals in our approach. We found significant reduction of contractile protein markers: smooth muscle myosin heavy chain (smMHC and calponin and reduced Ca2+ response to contractile agonist in dystrophin deficient cells. Immunocytochemistry revealed reduced stress fibers and number of smMHC positive cells in dystrophin-deficient cells, when compared to control. Immunoblot analysis of Akt1, GSK3β and mTOR phosphorylation further revealed that downstream PI3K signaling, which is essential for phenotype maturation, was suppressed in dystrophin deficient cell cultures. Tracheal rings from mdx mice showed significant reduction in the isometric contraction to methacholine (MCh when compared to genetic control BL10ScSnJ mice (wild-type. In vivo lung function studies using a small animal ventilator revealed a significant reduction in peak airway resistance induced by maximum concentrations of inhaled MCh in mdx mice, while there was no change in other lung function parameters. These data show that the lack of dystrophin is associated with a concomitant suppression of ASM cell phenotype maturation in vitro, ASM contraction ex vivo and lung function in vivo, indicating that a linkage between the DGC and the actin cytoskeleton via dystrophin is a determinant of the phenotype and functional properties of ASM.

  7. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Viitanen, Matti [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Department of Geriatrics, Turku City Hospital and University of Turku, Turku (Finland); Sundström, Erik [Division of Neurodegeneration, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Baumann, Marc [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Poyhonen, Minna [Department of Clinical Genetics, Helsinki University Hospital, HUSLAB, Helsinki (Finland); Tikka, Saara [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Behbahani, Homira, E-mail: homira.behbahani@ki.se [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Karolinska Institutet Alzheimer' s Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden)

    2013-02-01

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψ{sub m}) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  8. Relationship between muscle strength parameters and functional capacity in persons with mild to moderate degree multiple sclerosis

    DEFF Research Database (Denmark)

    Kjølhede, Tue; Vissing, Kristian; Langeskov-Christensen, Daniel

    2015-01-01

    BACKGROUND: Maximal muscle strength has been shown to be an important predictor of functional capacity for persons with multiple sclerosis (PwMS). Another muscle strength parameter known to be important for functional capacity in other patient groups is rate of force development (RFD) in knee...... is the better predictor of walking performance in persons with mild to moderate multiple sclerosis. RFD, although also important for functional capacity, is a less strong predictor. Maximal strength of the knee extensors, rather than the knee flexors, predicted performance in the stairclimb and 5STS tests....

  9. "Functional" Inspiratory and Core Muscle Training Enhances Running Performance and Economy.

    Science.gov (United States)

    Tong, Tomas K; McConnell, Alison K; Lin, Hua; Nie, Jinlei; Zhang, Haifeng; Wang, Jiayuan

    2016-10-01

    Tong, TK, McConnell, AK, Lin, H, Nie, J, Zhang, H, and Wang, J. "Functional" inspiratory and core muscle training enhances running performance and economy. J Strength Cond Res 30(10): 2942-2951, 2016-We compared the effects of two 6-week high-intensity interval training interventions. Under the control condition (CON), only interval training was undertaken, whereas under the intervention condition (ICT), interval training sessions were followed immediately by core training, which was combined with simultaneous inspiratory muscle training (IMT)-"functional" IMT. Sixteen recreational runners were allocated to either ICT or CON groups. Before the intervention phase, both groups undertook a 4-week program of "foundation" IMT to control for the known ergogenic effect of IMT (30 inspiratory efforts at 50% maximal static inspiratory pressure [P0] per set, 2 sets per day, 6 days per week). The subsequent 6-week interval running training phase consisted of 3-4 sessions per week. In addition, the ICT group undertook 4 inspiratory-loaded core exercises (10 repetitions per set, 2 sets per day, inspiratory load set at 50% post-IMT P0) immediately after each interval training session. The CON group received neither core training nor functional IMT. After the intervention phase, global inspiratory and core muscle functions increased in both groups (p ≤ 0.05), as evidenced by P0 and a sport-specific endurance plank test (SEPT) performance, respectively. Compared with CON, the ICT group showed larger improvements in SEPT, running economy at the speed of the onset of blood lactate accumulation, and 1-hour running performance (3.04% vs. 1.57%, p ≤ 0.05). The changes in these variables were interindividually correlated (r ≥ 0.57, n = 16, p ≤ 0.05). Such findings suggest that the addition of inspiratory-loaded core conditioning into a high-intensity interval training program augments the influence of the interval program on endurance running performance and that this may be

  10. Progressive shoulder-neck exercise on cervical muscle functions in middle-aged and senior patients with chronic neck pain.

    Science.gov (United States)

    Lin, I-Hsien; Chang, Kwang-Hwa; Liou, Tsan-Hon; Tsou, Chih-Min; Huang, Yi-Ching

    2018-02-01

    Although neck pain is a common musculoskeletal disorder, there is no consensus on suitable exercise methods for middle-aged and senior patients with chronic neck pain. Therefore, this study investigated the effectiveness of a 6-week shoulder-neck exercise intervention program on cervical muscle function improvement in patients aged 45 years or older with chronic neck pain. The aim of the present study was to evaluate the effects of progressive shoulder-neck exercise on cervical muscle functions of middle-aged and senior patients with chronic neck pain. A randomized controlled single-blind trial. Rehabilitation department of a hospital. A total of 72 subjects aged ≥45 years with chronic neck pain were randomly allocated to either an experimental group (N.=36; age 57.3±8.74 years) or a control group (N.=36; age 58.15±8.17 years). The control group received only traditional physiotherapy, whereas the experimental group participated in a 6-week shoulder-neck exercise program consisting of cranio-cervical flexion and progressive resistance exercises in addition to receiving traditional physiotherapy. The muscle functions of subjects in both groups were tested before the experiment and also after the intervention program. The pretest and posttest measured the cranio-cervical flexion test (CCFT) and the superficial cervical muscle strength. After the intervention, the experimental group had a 56.48 point improvement in the performance index of the CCFT (Pcervical muscle functions. This study confirmed that the 6-week progressive shoulder-neck exercise program can effectively improve cervical muscle function in middle-aged and senior patients with chronic neck pain. Progressive shoulder-neck exercise might provide positive effect on deep and superficial neck muscle strength in patients with chronic neck pain. Therefore, this study may serve as a reference for the clinical rehabilitation of patients with chronic neck pain.

  11. The Role of Muscle Mass, Muscle Quality, and Body Composition in Risk for the Metabolic Syndrome and Functional Decline in Older Adults: Topical Collection on Nutrition, Obesity, and Diabetes

    NARCIS (Netherlands)

    R.T. Mankowski (Robert T.); S.D. Anton (Stephen D.); M. Aubertin-Leheudre (Mylene)

    2015-01-01

    textabstractAbstract Age-related body composition changes include both loss of muscle mass (sarcopenia) and increase in fat mass, which jointly contribute to a decline in metabolic functions. Muscle quality is positively related to functional capacity and a lower risk for the development of the

  12. Haploinsufficiency of myostatin protects against aging-related declines in muscle function and enhances the longevity of mice.

    Science.gov (United States)

    Mendias, Christopher L; Bakhurin, Konstantin I; Gumucio, Jonathan P; Shallal-Ayzin, Mark V; Davis, Carol S; Faulkner, John A

    2015-08-01

    The molecular mechanisms behind aging-related declines in muscle function are not well understood, but the growth factor myostatin (MSTN) appears to play an important role in this process. Additionally, epidemiological studies have identified a positive correlation between skeletal muscle mass and longevity. Given the role of myostatin in regulating muscle size, and the correlation between muscle mass and longevity, we tested the hypotheses that the deficiency of myostatin would protect oldest-old mice (28-30 months old) from an aging-related loss in muscle size and contractility, and would extend the maximum lifespan of mice. We found that MSTN(+/-) and MSTN(-/-) mice were protected from aging-related declines in muscle mass and contractility. While no differences were detected between MSTN(+/+) and MSTN(-/-) mice, MSTN(+/-) mice had an approximately 15% increase in maximal lifespan. These results suggest that targeting myostatin may protect against aging-related changes in skeletal muscle and contribute to enhanced longevity. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  13. Role of preoperative pain, muscle function, and activity level in discharge readiness after fast-track hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Holm, Bente; Bandholm, Thomas; Lunn, Troels Haxholdt

    2014-01-01

    therefore investigated the role of preoperative pain and functional characteristics in discharge readiness and actual LOS in fast-track THA and TKA. METHODS: Before surgery, hip pain (THA) or knee pain (TKA), lower-extremity muscle power, functional performance, and physical activity were assessed...

  14. Why do insects enter chill coma? Low temperature and high extracellular potassium compromises muscle function in Locusta migratoria

    DEFF Research Database (Denmark)

    Findsen, Anders; Pedersen, Thomas Holm; Nielsen, Ole Bækgaard

    and a frequency of 60 Hz. To explore to what extent loss of force during cold exposure reflects loss of muscle function, all experiments were performed both in the presence and absence of TTX, which selectively inhibits motor nerve function in insects. Maximum tetanic force decreased approximately 75% when...

  15. Muscle strength and functional performance in patients at high risk of knee osteoarthritis: a follow-up study

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Aagaard, Per; Roos, Ewa M.

    2012-01-01

    PURPOSE: To investigate whether changes from 2 to 4 years post arthroscopic partial meniscectomy (APM) in mechanical muscle function and objectively measured function differ between the operated and contra-lateral leg of APM patients or compared with controls. METHODS: Twenty-two patients (age 46...

  16. S1P receptor signalling and RGS proteins; expression and function in vascular smooth muscle cells and transfected CHO cells

    NARCIS (Netherlands)

    Hendriks-Balk, Mariëlle C.; van Loenen, Pieter B.; Hajji, Najat; Michel, Martin C.; Peters, Stephan L. M.; Alewijnse, Astrid E.

    2009-01-01

    Sphingosine-1-phosphate (S1P) signalling via G protein-coupled receptors is important for the regulation of cell function and differentiation. Specific Regulators of G protein Signalling (RGS) proteins modulate the function of these receptors in many cell types including vascular smooth muscle cells

  17. Time-courses of lung function and respiratory muscle pressure generating capacity after spinal cord injury : a prospective cohort study

    NARCIS (Netherlands)

    Mueller, Gabi; de Groot, Sonja; van der Woude, Lucas; Hopman, Maria T E

    OBJECTIVE: To investigate the time-courses of lung function and respiratory muscle pressure generating capacity after spinal cord injury. DESIGN: Multi-centre, prospective cohort study. SUBJECTS: One hundred and nine subjects with recent, motor complete spinal cord injury. METHODS: Lung function and

  18. Regression analysis of radial artery pulse palpation as a potential tool for traditional Chinese medicine training education.

    Science.gov (United States)

    Huang, Po-Yu; Lin, Wen-Chen; Chiu, Bill Yuan-Chi; Chang, Hen-Hong; Lin, Kang-Ping

    2013-12-01

    Pulse palpation was an important part of the traditional Chinese medicine (TCM) vascular examination. It is challenging for new physicians to learn to differentiate between palpations of various pulse types, due to limited comparative learning time with established masters, and so normally it takes many years to master the art. The purpose of this study was to introduce an offline TCM skill evaluation and comparison system that makes available learning of palpation without the master's presence. We record patient's radial artery pulse using an existing pressure-based pulse acquisition system, then annotate it with teachers' evaluation when palpating the same patient, assigned as likelihood of it being each pulse type, e.g. wiry, slippery, hesitant. These training data were separated into per-doctor and per-skill databases for evaluation and comparison purposes, using the following novel procedure: each database was used as training data to a panel of time-series data-mining algorithms, driven by two validation tests, with the created training models evaluated in mean-squared-error. Each validation of the panel and training data yielded an array of error terms, and we chose one to quantitatively evaluate palpation techniques, giving way to compute self consistency and mutual-similarity across different practitioners and techniques. Our experiment of two practitioners and 396 per-processing samples yielded the following: one of the physicians has much higher value of self-consistency for all tested pulse types. Also, the two physicians have high similarity in how they palpate the slipper pulse (P) type, but very dissimilar for hesitant (H) type. This system of skill comparisons may be more broadly applied in places where supervised learning algorithms can detect and use meaningful features in the data; we chose a panel of algorithms previously shown to be effective for many time-series types, but specialized algorithms may be added to improve feature-specific aspect

  19. Positive effects of 1-year football and strength training on mechanical muscle function and functional capacity in elderly men.

    Science.gov (United States)

    Sundstrup, Emil; Jakobsen, Markus Due; Andersen, Lars Louis; Andersen, Thomas Rostgaard; Randers, Morten Bredsgaard; Helge, Jørn Wulff; Suetta, Charlotte; Schmidt, Jakob Friis; Bangsbo, Jens; Krustrup, Peter; Aagaard, Per

    2016-06-01

    A decline in physical capacity takes place with increasing age that negatively affects overall physical function including work ability and the ability to perform typical activities of daily living (ADL). The overall aim of the present study was to determine the neuromuscular adaptations to long-term (1 year) football and strength training in older untrained adults, and to assess the concurrent effect on functional ADL capacity. Twenty-seven healthy elderly males (68.2 ± 3.2 years) were randomly assigned to 12 months of either recreational football training (FT: n = 10), strength training (ST: n = 9) or served as inactive controls (CON: n = 8). Recreational football training consisted of small-sided training sessions whereas strength training consisted of high intensity exercises targeting the lower extremity and upper body. Maximal thigh muscle strength and rate of force development (RFD) were assessed with isokinetic dynamometry, while postural balance and vertical jumping performance were evaluated using force plate analysis. Furthermore, functional ability was evaluated by stair-ascent and chair-rising testing. A total of nine, nine and seven participants from FT, ST and CON, respectively, were included in the analysis. Both exercise regimens led to substantial gains in functional ability, evidenced by 24 and 18 % reduced stair-ascent time, and 32 and 21 % increased chair-rising performance in FT and ST, respectively (all P football training mainly resulted in enhanced hamstring strength (18 %, P football training mainly included enhanced strength and rapid force capacity of the hamstring muscles. Gains in functional ability were observed in response to both training regimens, evidenced by reduced stair-ascent time and increased chair-rising performance. Long-term football exercise and strength training both appear to be effective interventional strategies to improve factors of importance for ADL by counteracting the age-related decline in lower

  20. Baseline muscle mass is a poor predictor of functional overload-induced gain in the mouse model

    Directory of Open Access Journals (Sweden)

    Audrius Kilikevicius

    2016-11-01

    Full Text Available Genetic background contributes substantially to individual variability in muscle mass. Muscle hypertrophy in response to resistance training can also vary extensively. However, it is less clear if muscle mass at baseline is predictive of the hypertrophic response.The aim of this study was to examine the effect of genetic background on variability in muscle mass at baseline and in the adaptive response of the mouse fast- and slow-twitch muscles to overload. Males of eight laboratory mouse strains: C57BL/6J (B6, n=17, BALB/cByJ (n=7, DBA/2J (D2, n=12, B6.A-(rs3676616-D10Utsw1/Kjn (B6.A, n=9, C57BL/6J-Chr10A/J/NaJ (B6.A10, n=8, BEH+/+ (n=11, BEH (n=12 and DUHi (n=12, were studied. Compensatory growth of soleus and plantaris muscles was triggered by a 4-week overload induced by synergist unilateral ablation. Muscle weight in the control leg (baseline varied from 5.2±07 mg soleus and 11.4±1.3 mg plantaris in D2 mice to 18.0±1.7 mg soleus in DUHi and 43.7±2.6 mg plantaris in BEH (p<0.001 for both muscles. In addition, soleus in the B6.A10 strain was ~40% larger (p<0.001 compared to the B6. Functional overload increased muscle weight, however, the extent of gain was strain-dependent for both soleus (p<0.01 and plantaris (p<0.02 even after accounting for the baseline differences. For the soleus muscle, the BEH strain emerged as the least responsive, with a 1.3-fold increase, compared to a 1.7-fold gain in the most responsive D2 strain, and there was no difference in the gain between the B6.A10 and B6 strains. The BEH strain appeared the least responsive in the gain of plantaris as well, 1.3-fold, compared to ~1.5-fold gain in the remaining strains. We conclude that variation in muscle mass at baseline is not a reliable predictor of that in the overload-induced gain. This suggests that a different set of genes influence variability in muscle mass acquired in the process of normal development, growth and maintenance, and in the process of adaptive

  1. Hydrogen peroxide production regulates the mitochondrial function in insulin resistant muscle cells: effect of catalase overexpression.

    Science.gov (United States)

    Barbosa, Marina R; Sampaio, Igor H; Teodoro, Bruno G; Sousa, Thais A; Zoppi, Claudio C; Queiroz, André L; Passos, Madla A; Alberici, Luciane C; Teixeira, Felipe R; Manfiolli, Adriana O; Batista, Thiago M; Cappelli, Ana Paula Gameiro; Reis, Rosana I; Frasson, Danúbia; Kettelhut, Isis C; Parreiras-e-Silva, Lucas T; Costa-Neto, Claudio M; Carneiro, Everardo M; Curi, Rui; Silveira, Leonardo R

    2013-10-01

    The mitochondrial redox state plays a central role in the link between mitochondrial overloading and insulin resistance. However, the mechanism by which the ROS induce insulin resistance in skeletal muscle cells is not completely understood. We examined the association between mitochondrial function and H2O2 production in insulin resistant cells. Our hypothesis is that the low mitochondrial oxygen consumption leads to elevated ROS production by a mechanism associated with reduced PGC1α transcription and low content of phosphorylated CREB. The cells were transfected with either the encoded sequence for catalase overexpression or the specific siRNA for catalase inhibition. After transfection, myotubes were incubated with palmitic acid (500μM) and the insulin response, as well as mitochondrial function and fatty acid metabolism, was determined. The low mitochondrial oxygen consumption led to elevated ROS production by a mechanism associated with β-oxidation of fatty acids. Rotenone was observed to reduce the ratio of ROS production. The elevated H2O2 production markedly decreased the PGC1α transcription, an effect that was accompanied by a reduced phosphorylation of Akt and CREB. The catalase transfection prevented the reduction in the phosphorylated level of Akt and upregulated the levels of phosphorylated CREB. The mitochondrial function was elevated and H2O2 production reduced, thus increasing the insulin sensitivity. The catalase overexpression improved mitochondrial respiration protecting the cells from fatty acid-induced, insulin resistance. This effect indicates that control of hydrogen peroxide production regulates the mitochondrial respiration preventing the insulin resistance in skeletal muscle cells by a mechanism associated with CREB phosphorylation and β-oxidation of fatty acids. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Neck muscle vibration can improve sensorimotor function in patients with neck pain.

    Science.gov (United States)

    Beinert, Konstantin; Keller, Martin; Taube, Wolfgang

    2015-03-01

    People with neck pain display a diminished joint position sense and disturbed postural control, which is thought to be a result of impaired somatosensory afferent activity and/or integration. Afferent processing can be artificially manipulated by vibration and was shown to reduce motor performance in healthy subjects. However, the effect of vibration on sensorimotor function in neck pain patients is scarcely investigated. To assess the effect of neck muscle vibration on joint position sense and postural control in neck pain subjects and healthy controls. Case control study. Thirteen neck pain patients and 10 healthy controls participated in the present study. Cervical joint position sense and dynamic and static postural stability. Short-term, targeted neck muscle vibration with 100 Hz was applied after baseline measurement. Vibration had opposite effects in patients and healthy subjects. Patients showed improved joint position sense (pneck pain. Thus, vibration may be used to counteract sensorimotor impairment of the cervical spine. Potential underlying mechanisms are discussed. Copyright © 2015. Published by Elsevier Inc.

  3. The effects of dietary protein intake on appendicular lean mass and muscle function in elderly men

    DEFF Research Database (Denmark)

    Mitchell, Cameron J; Milan, Amber M; Mitchell, Sarah M

    2017-01-01

    Background: The Recommended Daily Allowance (RDA) for protein intake in the adult population is widely promoted as 0.8 g · kg-1 · d-1 Aging may increase protein requirements, particularly to maintain muscle mass.Objective: We investigated whether controlled protein consumption at the current RDA...... or twice the RDA (2RDA) affects skeletal muscle mass and physical function in elderly men.Design: In this parallel-group randomized trial, 29 men aged >70 y [mean ± SD body mass index (in kg/m2): 28.3 ± 4.2] were provided with a complete diet containing either 0.8 (RDA) or 1.6 (2RDA) g protein · kg-1 · d-1...... energy balance (mean ± SD RDA: 209 ± 213 kcal/d; 2RDA 145 ± 214 kcal/d; P= 0.427 for difference between the groups). In comparison with RDA, whole-body lean mass increased in 2RDA (P = 0.001; 1.49 ± 1.30 kg, P

  4. Watermelon juice: potential functional drink for sore muscle relief in athletes.

    Science.gov (United States)

    Tarazona-Díaz, Martha P; Alacid, Fernando; Carrasco, María; Martínez, Ignacio; Aguayo, Encarna

    2013-08-07

    l-Citrulline is an excellent candidate to reduce muscle soreness, and watermelon is a fruit rich in this amino acid. This study investigated the potential of watermelon juice as a functional drink for athletes. An in vitro study of intestinal absorption of l-citrulline in Caco-2 cells was performed using unpasteurized (NW), pasteurized (80 °C for 40 s) watermelon juice (PW) and, as control, a standard of l-citrulline. l-citrulline bioavailability was greater when it was contained in a matrix of watermelon and when no heat treatment was applied. In the in vivo experiment (maximum effort test in a cycloergometer), seven athletes were supplied with 500 mL of natural watermelon juice (1.17 g of l-citrulline), enriched watermelon juice (4.83 g of l-citrulline plus 1.17 g from watermelon), and placebo. Both watermelon juices helped to reduce the recovery heart rate and muscle soreness after 24 h.

  5. Muscle Contraction.

    Science.gov (United States)

    Sweeney, H Lee; Hammers, David W

    2018-02-01

    SUMMARYMuscle cells are designed to generate force and movement. There are three types of mammalian muscles-skeletal, cardiac, and smooth. Skeletal muscles are attached to bones and move them relative to each other. Cardiac muscle comprises the heart, which pumps blood through the vasculature. Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance. Smooth muscle does not contain sarcomeres but uses the contraction of filaments of actin and myosin to constrict blood vessels and move the contents of hollow organs in the body. Here, we review the principal molecular organization of the three types of muscle and their contractile regulation through signaling mechanisms and discuss their major structural and functional similarities that hint at the possible evolutionary relationships between the cell types. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

  6. The measurement of reversible redox dependent post-translational modifications and their regulation of mitochondrial and skeletal muscle function

    Directory of Open Access Journals (Sweden)

    Philip A Kramer

    2015-11-01

    Full Text Available Mitochondrial oxidative stress is a common feature of skeletal myopathies across multiple conditions; however, the mechanism by which it contributes to skeletal muscle dysfunction remains controversial. Oxidative damage to proteins, lipids, and DNA has received the most attention, yet an important role for reversible redox post-translational modifications (PTMs in pathophysiology is emerging. The possibility that these PTMs can exert dynamic control of muscle function implicates them as a mechanism contributing to skeletal muscle dysfunction in chronic disease. Herein, we discuss the significance of thiol-based redox dependent modifications to mitochondrial, myofibrillar and excitation-contraction (EC coupling proteins with an emphasis on how these changes could alter skeletal muscle performance under chronically stressed conditions. A major barrier to a better mechanistic understanding of the role of reversible redox PTMs in muscle function is the technical challenges associated with accurately measuring the changes of site-specific redox PTMs. Here we will critically review current approaches with an emphasis on sample preparation artifacts, quantitation, and specificity. Despite these challenges, the ability to accurately quantify reversible redox PTMs is critical to understanding the mechanisms by which mitochondrial oxidative stress contributes to skeletal muscle dysfunction in chronic diseases.

  7. The Measurement of Reversible Redox Dependent Post-translational Modifications and Their Regulation of Mitochondrial and Skeletal Muscle Function

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Philip A.; Duan, Jicheng; Qian, Wei-Jun; Marcinek, David J.

    2015-11-25

    Mitochondrial oxidative stress is a common feature of skeletal myopathies across multiple conditions; however, the mechanism by which it contributes to skeletal muscle dysfunction remains controversial. Oxidative damage to proteins, lipids, and DNA has received the most attention, yet an important role for reversible redox post-translational modifications (PTMs) in pathophysiology is emerging. The possibility that these PTMs can exert dynamic control of muscle function implicates them as a mechanism contributing to skeletal muscle dysfunction in chronic disease. Herein, we discuss the significance of thiol-based redox dependent modifications to mitochondrial, myofibrillar and excitation-contraction (EC) coupling proteins with an emphasis on how these changes could alter skeletal muscle performance under chronically stressed conditions. A major barrier to a better mechanistic understanding of the role of reversible redox PTMs in muscle function is the technical challenges associated with accurately measuring the changes of site-specific redox PTMs. Here we will critically review current approaches with an emphasis on sample preparation artifacts, quantitation, and specificity. Despite these challenges, the ability to accurately quantify reversible redox PTMs is critical to understanding the mechanisms by which mitochondrial oxidative stress contributes to skeletal muscle dysfunction in chronic diseases.

  8. Evaluation of respiratory muscles activity by means of cross mutual information function at different levels of ventilatory effort.

    Science.gov (United States)

    Alonso, Joan Francesc; Mañanas, Miguel A; Hoyer, Dirk; Topor, Zbigniew L; Bruce, Eugene N

    2007-09-01

    Analysis of respiratory muscles activity is an effective technique for the study of pulmonary diseases such as obstructive sleep apnea syndrome (OSAS). Respiratory diseases, especially those associated with changes in the mechanical properties of the respiratory apparatus, are often associated with disruptions of the normally highly coordinated contractions of respiratory muscles. Due to the complexity of the respiratory control, the assessment of OSAS related dysfunctions by linear methods are not sufficient. Therefore, the objective of this study was the detection of diagnostically relevant nonlinear complex respiratory mechanisms. Two aims of this work were: (1) to assess coordination of respiratory muscles contractions through evaluation of interactions between respiratory signals and myographic signals through nonlinear analysis by means of cross mutual information function (CMIF); (2) to differentiate between functioning of respiratory muscles in patients with OSAS and in normal subjects. Electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from three respiratory muscles: genioglossus, sternomastoid and diaphragm. Inspiratory pressure and flow were also acquired. All signals were measured in eight patients with OSAS and eight healthy subjects during an increased respiratory effort while awake. Several variables were defined and calculated from CMIF in order to describe correlation between signals. The results indicate different nonlinear couplings of respiratory muscles in both populations. This effect is progressively more evident at higher levels of respiratory effort.

  9. Analysis of respiratory and muscle activity by means of cross information function between ventilatory and myographic signals.

    Science.gov (United States)

    Alonso, J F; Mañanas, M A; Hoyer, D; Topor, Z L; Bruce, E N

    2004-01-01

    Analysis of respiratory muscle activity is a promising technique for the study of pulmonary diseases such as obstructive sleep apnea syndrome (OSAS). Evaluation of interactions between muscles is very useful in order to determine the muscular pattern during an exercise. These interactions have already been assessed by means of different linear techniques like cross-spectrum, magnitude squared coherence or cross-correlation. The aim of this work is to evaluate interactions between respiratory and myographic signals through nonlinear analysis by means of cross mutual information function (CMIF), and finding out what information can be extracted from it. Some parameters are defined and calculated from CMIF between ventilatory and myographic signals of three respiratory muscles. Finally, differences in certain parameters were obtained between OSAS patients and healthy subjects indicating different respiratory muscle couplings.

  10. Dual AAV therapy ameliorates exercise-induced muscle injury and functional ischemia in murine models of Duchenne muscular dystrophy.

    Science.gov (United States)

    Zhang, Yadong; Yue, Yongping; Li, Liang; Hakim, Chady H; Zhang, Keqing; Thomas, Gail D; Duan, Dongsheng

    2013-09-15

    Neuronal nitric oxide synthase (nNOS) membrane delocalization contributes to the pathogenesis of Duchenne muscular dystrophy (DMD) by promoting functional muscle ischemia and exacerbating muscle injury during exercise. We have previously shown that supra-physiological expression of nNOS-binding mini-dystrophin restores normal blood flow regulation and prevents functional ischemia in transgenic mdx mice, a DMD model. A critical next issue is whether systemic dual adeno-associated virus (AAV) gene therapy can restore nNOS-binding mini-dystrophin expression and mitigate muscle activity-related functional ischemia and injury. Here, we performed systemic gene transfer in mdx and mdx4cv mice using a pair of dual AAV vectors that expressed a 6 kb nNOS-binding mini-dystrophin gene. Vectors were packaged in tyrosine mutant AAV-9 and co-injected (5 × 10(12) viral genome particles/vector/mouse) via the tail vein to 1-month-old dystrophin-null mice. Four months later, we observed 30-50% mini-dystrophin positive myofibers in limb muscles. Treatment ameliorated histopathology, increased muscle force and protected against eccentric contraction-induced injury. Importantly, dual AAV therapy successfully prevented chronic exercise-induced muscle force drop. Doppler hemodynamic assay further showed that therapy attenuated adrenergic vasoconstriction in contracting muscle. Our results suggest that partial transduction can still ameliorate nNOS delocalization-associated functional deficiency. Further evaluation of nNOS binding mini-dystrophin dual AAV vectors is warranted in dystrophic dogs and eventually in human patients.

  11. Agreement and Reliability of Functional Performance and Muscle Power in Patients with Advanced Osteoarthritis of the Hip or Knee

    DEFF Research Database (Denmark)

    Villadsen, Allan; Roos, Ewa M; Overgaard, Søren

    2012-01-01

    -time repeated chair stands, and repeated unilateral knee bending). RESULTS: For single-joint and multijoint maximal peak power and functional performance measures, we demonstrated poor (CVws, approximately 25%, single-joint hip extension) and moderate (CVws, approximately 15%, multijoint leg extension press......OBJECTIVE: The purpose of this study was to test the reproducibility and clinical feasibility of three functional performance measures and five single-joint or multijoint muscle power measures. DESIGN: Twenty patients with a mean age of 68.7 ± 7.2 yrs with severe hip or knee osteoarthritis were...... assessed for test-retest reliability and agreement on two occasions 1 wk apart. The outcomes were maximal single-joint muscle power (hip extension/abduction and knee extension/flexion), maximal muscle power during multijoint leg extension press, and functional performance measures (20-m walk, five...

  12. What's So Special about FGF19-Unique Effects Reported on Skeletal Muscle Mass and Function.

    Science.gov (United States)

    Glass, David J

    2017-08-01

    In a recent study published in Nature Medicine, Benoit et al. (2017) reported unique effects of FGF19 on mouse skeletal muscle: FGF19 induced skeletal muscle hypertrophy and blocked muscle atrophy, acting via FGF receptors and ßKlotho, while a related FGF21 hormone was ineffective. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Functional analysis of inter-individual transcriptome differential expression in pig longissimus muscle

    NARCIS (Netherlands)

    Zhao, S.; Hulsegge, B.; Harders, F.L.; Bossers, R.; Keuning, E.; Hoekman, A.J.W.; Hoving-Bolink, A.H.; Pas, te M.F.W.

    2013-01-01

    Selection of pigs for increased meat production or improved meat quality changes muscle mass and muscle composition. This will be related to transcriptome expression profile changes in muscle tissue, generating inter-individual differences. This study investigated the differentially expressed genes

  14. Abnormal muscle membrane function in fibromyalgia patients and its relationship to the number of tender points

    NARCIS (Netherlands)

    Klaver-Krol, E.G.; Zwarts, M.J.; ten Klooster, Peter M.; Rasker, Johannes J.

    2012-01-01

    Objective. Fibromyalgia (FM) is a disorder characterised by chronic widespreadpain in soft tissues, especially in muscles. Previous research has demonstrateda higher muscle fibre conduction velocity (CV) in painful muscles of FM patients. The primary goal of this study was to investigate whether

  15. Evaluation of skeletal and cardiac muscle function after chronic administration of thymosin beta-4 in the dystrophin deficient mouse.

    Directory of Open Access Journals (Sweden)

    Christopher F Spurney

    2010-01-01

    Full Text Available Thymosin beta-4 (Tbeta4 is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. We studied the effects of chronic administration of Tbeta4 on the skeletal and cardiac muscle of dystrophin deficient mdx mice, the mouse model of Duchenne muscular dystrophy. Female wild type (C57BL10/ScSnJ and mdx mice, 8-10 weeks old, were treated with 150 microg of Tbeta4 twice a week for 6 months. To promote muscle pathology, mice were exercised for 30 minutes twice a week. Skeletal and cardiac muscle function were assessed via grip strength and high frequency echocardiography. Localization of Tbeta4 and amount of fibrosis were quantified using immunohistochemistry and Gomori's tri-chrome staining, respectively. Mdx mice treated with Tbeta4 showed a significant increase in skeletal muscle regenerating fibers compared to untreated mdx mice. Tbeta4 stained exclusively in the regenerating fibers of mdx mice. Although untreated mdx mice had significantly decreased skeletal muscle strength compared to untreated wild type, there were no significant improvements in mdx mice after treatment. Systolic cardiac function, measured as percent shortening fraction, was decreased in untreated mdx mice compared to untreated wild type and there was no significant difference after treatment in mdx mice. Skeletal and cardiac muscle fibrosis were also significantly increased in untreated mdx mice compared to wild type, but there was no significant improvement in treated mdx mice. In exercised dystrophin deficient mice, chronic administration of Tbeta4 increased the number of regenerating fibers in skeletal muscle and could have a potential role in treatment of skeletal muscle disease in Duchenne muscular dystrophy.

  16. Experiences of intervertebral motion palpation in osteopathic practice - A qualitative interview study among Swedish osteopaths.

    Science.gov (United States)

    Sposato, Niklas S; Bjerså, Kristofer

    2017-01-01

    Assessment in manual therapy includes quantitative and qualitative procedures, and intervertebral motion palpation (IMP) is one of the core assessment methods in osteopathic practice. The aim of this study was to explore osteopathic practitioners' experiences of clinical decision-making and IMP as a diagnostic tool for planning and evaluation of osteopathic interventions. The study was conducted with semi-structured interviews that included eight informants. Content analysis was used as the analytical procedure. In total, three categories emerged from the analysis: strategic decision-making, diagnostic usability of IMP, and treatment applicability of IMP. The study indicated that IMP was considered relevant and was given particular importance in cases where IMP findings confirmed clinical information attained from other stages in the diagnostic process as a whole. However, IMP findings were experienced as less important if they were not correlated to other findings. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Functional role of stromal interaction molecule 1 (STIM1) in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Takahashi, Yoichiro; Watanabe, Hiroyuki; Murakami, Manabu; Ono, Kyoichi; Munehisa, Yoshiko; Koyama, Takashi; Nobori, Kiyoshi; Iijima, Toshihiko; Ito, Hiroshi

    2007-01-01

    We investigated the functional role of STIM1, a Ca 2+ sensor in the endoplasmic reticulum (ER) that regulates store-operated Ca 2+ entry (SOCE), in vascular smooth muscle cells (VSMCs). STIM1 was mainly localized at the ER and plasma membrane. The knockdown of STIM1 expression by small interfering (si) RNA drastically decreased SOCE. In contrast, an EF-hand mutant of STIM1, STIM1 E87A , produced a marked increase in SOCE, which was abolished by co-transfection with siRNA to transient receptor potential canonical 1 (TRPC1). In addition, transfection with siRNA against STIM1 suppressed phosphorylation of cAMP-responsive element binding protein (CREB) and cell growth. These results suggest that STIM1 is an essential component of SOCE and that it is involved in VSMC proliferation

  18. Knee function and knee muscle strength in middle-aged patients with degenerative meniscal tears eligible for arthroscopic partial meniscectomy

    DEFF Research Database (Denmark)

    Stensrud, Silje; Risberg, May Arna; Roos, Ewa M.

    2014-01-01

    BACKGROUND: Functional limitations exist postmeniscectomy, but preoperative data are scarce. PURPOSE: To examine knee function, knee muscle strength and performance in middle-aged patients with degenerative meniscal tears, eligible for arthroscopic partial meniscectomy. STUDY DESIGN: Cross......-sectional study. METHODS: Eighty-two participants with MRI verified degenerative meniscal tear (35% women, mean age 49 years) answered the Knee injury and Osteoarthritis Outcome Score (KOOS) and were tested for isokinetic knee muscle strength and lower extremity performance (one-leg hop for distance, 6 m timed...

  19. Development of a phantom mimicking the functional and structural behaviors of the thigh muscles characterized with magnetic resonance elastography technique.

    Science.gov (United States)

    Chakouch, Mashhour K; Charleux, Fabrice; Bensamoun, Sabine F

    2015-01-01

    Magnetic Resonance Elastography (MRE) is a non invasive technique based on the propagation of shear waves in soft tissues providing the quantification of the mechanical properties [1]. MRE was successfully applied to healthy and pathological muscles. However, the MRE muscle methods must be further improved to characterize the deep muscles. A way will be to develop phantom mimicking the muscle behavior in order to set up new MRE protocol. Thus, the purpose of this study is to create a phantom composed of a similar skeletal muscle architecture (fiber, aponorosis) and equivalent elastic properties as a function of the muscle state (passive or active). Two homogeneous phantoms were manufactured with different concentrations of plastisol to simulate the elastic properties in relaxed (50% of plastisol) and contracted (70% of plastisol) muscle conditions. Moreover, teflon tubing pipes (D = 0.9 mm) were thread in the upper part of the phantom (50%) to represent the muscle fibers and a plastic sheet (8 × 15 cm) was also included in the middle of the phantom to mimic the aponeurosis structure. Subsequently, MRE tests were performed with two different pneumatic drivers, tube and round, (f = 90Hz) to analyze the effect of the type of driver on the wave propagation. Then, the wavelength was measured from the phase images to obtain the elastic properties (shear modulus). Both phantoms revealed elastic properties which were in the same range as in vivo muscle in passive (μ(50%) = 2.40 ± 0.18 kPa ) and active (6.24 ± 0.21 kPa) states. The impact of the type of driver showed higher values (about 1.2kPa) with the tube. The analysis of the wave behavior revealed a sliding along the plastic sheet as it was observed for in vivo muscle study. The wave was also sensitive to the presence of the fibers where gaps were identified. The present study demonstrates the ability of the phantom to mimic the structural and functional properties of the muscle.

  20. Predictive Value of Upper Limb Muscles and Grasp Patterns on Functional Outcome in Cervical Spinal Cord Injury.

    Science.gov (United States)

    Velstra, Inge-Marie; Bolliger, Marc; Krebs, Jörg; Rietman, Johan S; Curt, Armin

    2016-05-01

    To determine which single or combined upper limb muscles as defined by the International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI); upper extremity motor score (UEMS) and the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP), best predict upper limb function and independence in activities of daily living (ADLs) and to assess the predictive value of qualitative grasp movements (QlG) on upper limb function in individuals with acute tetraplegia. As part of a Europe-wide, prospective, longitudinal, multicenter study ISNCSCI, GRASSP, and Spinal Cord Independence Measure (SCIM III) scores were recorded at 1 and 6 months after SCI. For prediction of upper limb function and ADLs, a logistic regression model and unbiased recursive partitioning conditional inference tree (URP-CTREE) were used. Results: Logistic regression and URP-CTREE revealed that a combination of ISNCSCI and GRASSP muscles (to a maximum of 4) demonstrated the best prediction (specificity and sensitivity ranged from 81.8% to 96.0%) of upper limb function and identified homogenous outcome cohorts at 6 months. The URP-CTREE model with the QlG predictors for upper limb function showed similar results. Prediction of upper limb function can be achieved through a combination of defined, specific upper limb muscles assessed in the ISNCSCI and GRASSP. A combination of a limited number of proximal and distal muscles along with an assessment of grasping movements can be applied for clinical decision making for rehabilitation interventions and clinical trials. © The Author(s) 2015.

  1. Concurrent assessments of lower limb loading patterns, mechanical muscle strength and functional performance in ACL-patients - A cross-sectional study

    DEFF Research Database (Denmark)

    Holsgaard-Larsen, Anders; Jensen, C; Mortensen, N H M

    2014-01-01

    Full recovery in muscle strength and functional performance may not be achieved after ACL-injury. Aim: The aim of this study is to investigate loading patterns during jumping, muscle function and functional performance in ACL-reconstructed patients and to investigate the origin of between...

  2. Metabolic and functional effects of beta-hydroxy-beta-methylbutyrate (HMB) supplementation in skeletal muscle.

    Science.gov (United States)

    Pinheiro, Carlos Hermano da Justa; Gerlinger-Romero, Frederico; Guimarães-Ferreira, Lucas; de Souza, Alcione Lescano; Vitzel, Kaio Fernando; Nachbar, Renato Tadeu; Nunes, Maria Tereza; Curi, Rui

    2012-07-01

    Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite derived from leucine. The anti-catabolic effect of HMB is well documented but its effect upon skeletal muscle strength and fatigue is still uncertain. In the present study, male Wistar rats were supplemented with HMB (320 mg/kg per day) for 4 weeks. Placebo group received saline solution only. Muscle strength (twitch and tetanic force) and resistance to acute muscle fatigue of the gastrocnemius muscle were evaluated by direct electrical stimulation of the sciatic nerve. The content of ATP and glycogen in red and white portions of gastrocnemius muscle were also evaluated. The effect of HMB on citrate synthase (CS) activity was also investigated. Muscle tetanic force was increased by HMB supplementation. No change was observed in time to peak of contraction and relaxation time. Resistance to acute muscle fatigue during intense contractile activity was also improved after HMB supplementation. Glycogen content was increased in both white (by fivefold) and red (by fourfold) portions of gastrocnemius muscle. HMB supplementation also increased the ATP content in red (by twofold) and white (1.2-fold) portions of gastrocnemius muscle. CS activity was increased by twofold in red portion of gastrocnemius muscle. These results support the proposition that HMB supplementation have marked change in oxidative metabolism improving muscle strength generation and performance during intense contractions.

  3. Early Stress History Alters Serum Insulin-Like Growth Factor-1 and Impairs Muscle Mitochondrial Function in Adult Male Rats.

    Science.gov (United States)

    Ghosh, S; Banerjee, K K; Vaidya, V A; Kolthur-Seetharam, U

    2016-09-01

    Early-life adversity is associated with an enhanced risk for adult psychopathology. Psychiatric disorders such as depression exhibit comorbidity for metabolic dysfunction, including obesity and diabetes. However, it is poorly understood whether, besides altering anxiety and depression-like behaviour, early stress also evokes dysregulation of metabolic pathways and enhances vulnerability for metabolic disorders. We used the rodent model of the early stress of maternal separation (ES) to examine the effects of early stress on serum metabolites, insulin-like growth factor (IGF)-1 signalling, and muscle mitochondrial content. Adult ES animals exhibited dyslipidaemia, decreased serum IGF1 levels, increased expression of liver IGF binding proteins, and a decline in the expression of specific metabolic genes in the liver and muscle, including Pck1, Lpl, Pdk4 and Hmox1. These changes occurred in the absence of alterations in body weight, food intake, glucose tolerance, insulin tolerance or insulin levels. ES animals also exhibited a decline in markers of muscle mitochondrial content, such as mitochondrial DNA levels and expression of TFAM (transcription factor A, mitochondrial). Furthermore, the expression of several genes involved in mitochondrial function, such as Ppargc1a, Nrf1, Tfam, Cat, Sesn3 and Ucp3, was reduced in skeletal muscle. Adult-onset chronic unpredictable stress resulted in overlapping and distinct consequences from ES, including increased circulating triglyceride levels, and a decline in the expression of specific metabolic genes in the liver and muscle, with no change in the expression of genes involved in muscle mitochondrial function. Taken together, our results indicate that a history of early adversity can evoke persistent changes in circulating IGF-1 and muscle mitochondrial function and content, which could serve to enhance predisposition for metabolic dysfunction in adulthood. © 2016 British Society for Neuroendocrinology.

  4. Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults.

    Science.gov (United States)

    Misic, Mark M; Rosengren, Karl S; Woods, Jeffrey A; Evans, Ellen M

    2007-01-01

    Muscle mass, strength and fitness play a role in lower-extremity physical function (LEPF) in older adults; however, the relationships remain inadequately characterized. This study aimed to examine the relationships between leg mineral free lean mass (MFLM(LEG)), leg muscle quality (leg strength normalized for MFLM(LEG)), adiposity, aerobic fitness and LEPF in community-dwelling healthy elderly subjects. Fifty-five older adults (69.3 +/- 5.5 years, 36 females, 19 males) were assessed for leg strength using an isokinetic dynamometer, body composition by dual energy X-ray absorptiometry and aerobic fitness via a treadmill maximal oxygen consumption test. LEPF was assessed using computerized dynamic posturography and stair ascent/descent, a timed up-and-go task and a 7-meter walk with and without an obstacle. Muscle strength, muscle quality and aerobic fitness were similarly correlated with static LEPF tests (r range 0.27-0.40, p < 0.05); however, the strength of the independent predictors was not robust with explained variance ranging from 9 to 16%. Muscle quality was the strongest correlate of all dynamic LEPF tests (r range 0.54-0.65, p < 0.001). Using stepwise linear regression analysis, muscle quality was the strongest independent predictor of dynamic physical function explaining 29-42% of the variance (p < 0.001), whereas aerobic fitness or body fat mass explained 5-6% of the variance (p < 0.05) depending on performance measure. Muscle quality is the most important predictor, and aerobic fitness and fat mass are secondary predictors of LEPF in community-dwelling older adults. These findings support the importance of exercise, especially strength training, for optimal body composition, and maintenance of strength and physical function in older adults.

  5. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Directory of Open Access Journals (Sweden)

    Eric A Pohlmeyer

    2009-06-01

    Full Text Available Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  6. The Functional Role of Calcineurin in Hypertrophy, Regeneration, and Disorders of Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Kunihiro Sakuma

    2010-01-01

    Full Text Available Skeletal muscle uses calcium as a second messenger to respond and adapt to environmental stimuli. Elevations in intracellular calcium levels activate calcineurin, a serine/threonine phosphatase, resulting in the expression of a set of genes involved in the maintenance, growth, and remodeling of skeletal muscle. In this review, we discuss the effects of calcineurin activity on hypertrophy, regeneration, and disorders of skeletal muscle. Calcineurin is a potent regulator of muscle remodeling, enhancing the differentiation through upregulation of myogenin or MEF2A and downregulation of the Id1 family and myostatin. Foxo may also be a downstream candidate for a calcineurin signaling molecule during muscle regeneration. The strategy of controlling the amount of calcineurin may be effective for the treatment of muscular disorders such as DMD, UCMD, and LGMD. Activation of calcineurin produces muscular hypertrophy of the slow-twitch soleus muscle but not fast-twitch muscles.

  7. STIM1 as a key regulator for Ca2+ homeostasis in skeletal-muscle development and function

    Directory of Open Access Journals (Sweden)

    Kiviluoto Santeri

    2011-04-01

    Full Text Available Abstract Stromal interaction molecules (STIM were identified as the endoplasmic-reticulum (ER Ca2+ sensor controlling store-operated Ca2+ entry (SOCE and Ca2+-release-activated Ca2+ (CRAC channels in non-excitable cells. STIM proteins target Orai1-3, tetrameric Ca2+-permeable channels in the plasma membrane. Structure-function analysis revealed the molecular determinants and the key steps in the activation process of Orai by STIM. Recently, STIM1 was found to be expressed at high levels in skeletal muscle controlling muscle function and properties. Novel STIM targets besides Orai channels are emerging. Here, we will focus on the role of STIM1 in skeletal-muscle structure, development and function. The molecular mechanism underpinning skeletal-muscle physiology points toward an essential role for STIM1-controlled SOCE to drive Ca2+/calcineurin/nuclear factor of activated T cells (NFAT-dependent morphogenetic remodeling programs and to support adequate sarcoplasmic-reticulum (SR Ca2+-store filling. Also in our hands, STIM1 is transiently up-regulated during the initial phase of in vitro myogenesis of C2C12 cells. The molecular targets of STIM1 in these cells likely involve Orai channels and canonical transient receptor potential (TRPC channels TRPC1 and TRPC3. The fast kinetics of SOCE activation in skeletal muscle seem to depend on the triad-junction formation, favoring a pre-localization and/or pre-formation of STIM1-protein complexes with the plasma-membrane Ca2+-influx channels. Moreover, Orai1-mediated Ca2+ influx seems to be essential for controlling the resting Ca2+ concentration and for proper SR Ca2+ filling. Hence, Ca2+ influx through STIM1-dependent activation of SOCE from the T-tubule system may recycle extracellular Ca2+ losses during muscle stimulation, thereby maintaining proper filling of the SR Ca2+ stores and muscle function. Importantly, mouse models for dystrophic pathologies, like Duchenne muscular dystrophy, point towards an

  8. Susceptibility to Hamstring Injuries in Soccer: A Prospective Study Using Muscle Functional Magnetic Resonance Imaging.

    Science.gov (United States)

    Schuermans, Joke; Van Tiggelen, Damien; Danneels, Lieven; Witvrouw, Erik

    2016-05-01

    Running-related hamstring strain injuries remain a delicate issue in several sports such as soccer. Their unremittingly high incidence and recurrence rates indicate that the underlying risk has not yet been fully identified. Among other factors, the importance of neuromuscular coordination and the quality of interplay between the different hamstring muscle bellies is thought to be a key determinant within the intrinsic injury risk. Muscle functional magnetic resonance imaging (mfMRI) is one of the tools that has been proven to be valid for evaluating intermuscular coordination. To investigate the risk of sustaining an index or recurring soccer-related hamstring injury by exploring metabolic muscle characteristics using mfMRI. Cohort study; Level of evidence, 2. A total of 27 healthy male soccer players and 27 soccer players with a history of hamstring injuries underwent standardized mfMRI. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exercise, and a postexercise scan. The exercise-related T2 change, or the signal intensity shift between both scans, was used to detect differences in metabolic characteristics between (1) the different hamstring muscle bellies and (2) the prospective cohorts based on the (re)occurrence of hamstring injuries during a follow-up period of 18 months. The risk of sustaining a first hamstring injury was associated with alterations in the intermuscular hierarchy in terms of the magnitude of the metabolic response after a heavy eccentric effort, with the dominant role of the semitendinosus set aside for a higher contribution of the biceps femoris (P = .017). Receiver operating characteristic (ROC) curve analysis demonstrated that this variable was significantly able to predict the occurrence of index injuries with a sensitivity of 100% and a specificity of 70% when the metabolic activity of the biceps femoris exceeded 10%. The risk of sustaining a reinjury was associated with a substantial deficit

  9. Highlights from the Functional Single Nucleotide Polymorphisms Associated with Human Muscle Size and Strength or FAMuSS Study

    Directory of Open Access Journals (Sweden)

    Linda S. Pescatello

    2013-01-01

    Full Text Available The purpose of the Functional Single Nucleotide Polymorphisms Associated with Human Muscle Size and Strength study or FAMuSS was to identify genetic factors that dictated the response of health-related fitness phenotypes to resistance exercise training (RT. The phenotypes examined were baseline muscle strength and muscle, fat, and bone volume and their response to RT. FAMuSS participants were 1300 young (24 years, healthy men (42% and women (58% that were primarily of European-American descent. They were genotyped for ~500 polymorphisms and completed the Paffenbarger Physical Activity Questionnaire to assess energy expenditure and time spent in light, moderate, and vigorous intensity habitual physical activity and sitting. Subjects then performed a 12-week progressive, unilateral RT program of the nondominant arm with the dominant arm used as a comparison. Before and after RT, muscle strength was measured with the maximum voluntary contraction and one repetition maximum, while MRI measured muscle, fat, and bone volume. We will discuss the history of how FAMuSS originated, provide a brief overview of the FAMuSS methods, and summarize our major findings regarding genotype associations with muscle strength and size, body composition, cardiometabolic biomarkers, and physical activity.

  10. Dynamics of tropomyosin in muscle fibers as monitored by saturation transfer EPR of bi-functional probe.

    Directory of Open Access Journals (Sweden)

    Roni F Rayes

    Full Text Available The dynamics of four regions of tropomyosin was assessed using saturation transfer electron paramagnetic resonance in the muscle fiber. In order to fully immobilize the spin probe on the surface of tropomyosin, a bi-functional spin label was attached to i,i+4 positions via cysteine mutagenesis. The dynamics of bi-functionally labeled tropomyosin mutants decreased by three orders of magnitude when reconstituted into "ghost muscle fibers". The rates of motion varied along the length of tropomyosin with the C-terminus position 268/272 being one order of magnitude slower then N-terminal domain or the center of the molecule. Introduction of troponin decreases the dynamics of all four sites in the muscle fiber, but there was no significant effect upon addition of calcium or myosin subfragment-1.

  11. Are there two forms of isometric muscle action? Results of the experimental study support a distinction between a holding and a pushing isometric muscle function.

    Science.gov (United States)

    Schaefer, Laura V; Bittmann, Frank N

    2017-01-01

    In isometric muscle function, there are subjectively two different modes of performance: one can either hold isometrically - thus resist an impacting force - or push isometrically - therefore work against a stable resistance. The purpose of this study is to investigate whether or not two different isometric muscle actions - the holding vs. pushing one (HIMA vs PIMA) - can be distinguished by objective parameters. Ten subjects performed two different measuring modes at 80% of MVC realized by a special pneumatic system. During HIMA the subject had to resist the defined impacting force of the pneumatic system in an isometric position, whereby the force of the cylinder works in direction of elbow flexion against the subject. During PIMA the subject worked isometrically in direction of elbow extension against a stable position of the system. The signals of pressure, force, acceleration and mechanomyography/-tendography (MMG/MTG) of the elbow extensor (MMGtri/MTGtri) and the abdominal muscle (MMGobl) were recorded and evaluated concerning the duration of maintaining the force level (force endurance) and the characteristics of MMG-/MTG-signals. Statistical group differences comparing HIMA vs. PIMA were estimated using SPSS. Significant differences between HIMA and PIMA were especially apparent regarding the force endurance: During HIMA the subjects showed a decisively shorter time of stable isometric position (19 ± 8 s) in comparison with PIMA (41 ± 24 s; p  = .005). In addition, during PIMA the longest isometric plateau amounted to 59.4% of the overall duration time of isometric measuring, during HIMA it lasted 31.6% ( p  = .000). The frequency of MMG/MTG did not show significant differences. The power in the frequency ranges of 8-15 Hz and 10-29 Hz was significantly higher in the MTGtri performing HIMA compared to PIMA (but not for the MMGs). The amplitude of MMG/MTG did not show any significant difference considering the whole measurement. However

  12. Reliability of palpation of the radial artery compared with auscultation of the brachial artery in measuring SBP

    NARCIS (Netherlands)

    van der Hoeven, Niels V.; van den Born, Bert-Jan H.; van Montfrans, Gert A.

    2011-01-01

    Background Systolic blood pressure contributes more to cardiovascular disease than DBP, especially in elderly persons. Palpation of the radial artery to assess SBP - Riva-Rocci's technique-may be an attractive alternative for auscultatory SBP in these patients. Therefore, we investigated the

  13. Three finger palpation technique of vas deferens for keyhole vasectomy in spotted (Axis axis and sambar deer (Cervus unicolor

    Directory of Open Access Journals (Sweden)

    B. J. William

    2014-09-01

    Full Text Available Aim: Vasectomy is performed in deer for population control, maintain pedigreed animals and prevent inbreeding. Conventional procedure of vasectomy required a long-term anesthesia and longer duration of hospitalization, which often result in stress, morbidity and mortality. A study was conducted to capture, neuter and release the deer with minimal hospitalization and stress by adopting three finger palpation technique of vas deferens and performing vasectomy through a key-hole incision. Materials and Methods: The study was conducted on three spotted male deer and three sambar male deer, which were immobilized with a mixture of xylazine at the dose of 1.00 mg/kg and ketamine at the dose of 5.00 mg/kg. The vas deferens could be palpated as a piece of cooked spaghetti at the neck of the scrotum on the anterior aspect by three finger palpation technique and was able to fix the vas deferens between the thumb and middle finger. Through a key-hole incision of <5 mm length, the vas deferens was exteriorized and resected using electrocautery and the skin incision was sealed with methyl methacrylate. The deer were released on the same day, and no post-operative complication was noticed. Conclusion: The study revealed that three finger palpation technique of vas deferens provided guidance for easy access to vas deferens for vasectomy in deer with less hospitalization, and the deer could be released on the same day.

  14. A parametric model of muscle moment arm as a function of joint angle: application to the dorsiflexor muscle group in mice.

    Science.gov (United States)

    Miller, S W; Dennis, R G

    1996-12-01

    A parametric model was developed to describe the relationship between muscle moment arm and joint angle. The model was applied to the dorsiflexor muscle group in mice, for which the moment arm was determined as a function of ankle angle. The moment arm was calculated from the torque measured about the ankle upon application of a known force along the line of action of the dorsiflexor muscle group. The dependence of the dorsiflexor moment arm on ankle angle was modeled as r = R sin(a + delta), where r is the moment arm calculated from the measured torque and a is the joint angle. A least-squares curve fit yielded values for R, the maximum moment arm, and delta, the angle at which the maximum moment arm occurs as offset from 90 degrees. Parametric models were developed for two strains of mice, and no differences were found between the moment arms determi