Displaying publications 81 - 100 of 248 in total

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  1. Fulltext Hepatocellular carcinoma with disseminated skeletal muscle metastasis
    Rahim EA, Noh MS, Ngah NA, Suraini MS, Yusof MM
    Acta Radiol Open, 2017 Jul;6(7):2058460117716705.
    PMID: 28811928 DOI: 10.1177/2058460117716705
    Hepatocellular carcinoma (HCC) is the commonest primary tumor of the liver and carries a poor prognosis when diagnosed late or left untreated. Treatment relies heavily on the stage of the tumor when diagnosed. Extrahepatic metastasis is known to occur; these are mainly reported via autopsy studies or isolated case reports. Knowledge of extrahepatic metastasis is crucial in order to avoid unnecessary surgery. We report a rare case of a patient at our center, diagnosed to have HCC, who underwent treatment successfully, only to come back with extrahepatic metastasis to the skeletal muscles.
    Matched MeSH terms: Muscle, Skeletal
  2. Fulltext A New Approach to Noninvasive-Prolonged Fatigue Identification Based on Surface EMG Time-Frequency and Wavelet Features
    Jamaluddin FN, Ibrahim F, Ahmad SA
    J Healthc Eng, 2023;2023:1951165.
    PMID: 36756137 DOI: 10.1155/2023/1951165
    In sports, fatigue management is vital as adequate rest builds strength and enhances performance, whereas inadequate rest exposes the body to prolonged fatigue (PF) or also known as overtraining. This paper presents PF identification and classification based on surface electromyography (EMG) signals. An experiment was performed on twenty participants to investigate the behaviour of surface EMG during the inception of PF. PF symptoms were induced in accord with a five-day Bruce Protocol treadmill test on four lower extremity muscles: the biceps femoris (BF), rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL). The results demonstrate that the experiment successfully induces soreness, unexplained lethargy, and performance decrement and also indicate that the progression of PF can be observed based on changes in frequency features (ΔF med and ΔF mean) and time features (ΔRMS and ΔMAV) of surface EMG. This study also demonstrates the ability of wavelet index features in PF identification. Using a naïve Bayes (NB) classifier exhibits the highest accuracy based on time and frequency features with 98% in distinguishing PF on RF, 94% on BF, 9% on VL, and 97% on VM. Thus, this study has positively indicated that surface EMG can be used in identifying the inception of PF. The implication of the findings is significant in sports to prevent a greater risk of PF.
    Matched MeSH terms: Muscle, Skeletal
  3. Fulltext Mechanomyography and Torque during FES-Evoked Muscle Contractions to Fatigue in Individuals with Spinal Cord Injury
    Mohamad NZ, Hamzaid NA, Davis GM, Abdul Wahab AK, Hasnan N
    Sensors (Basel), 2017 Jul 14;17(7).
    PMID: 28708068 DOI: 10.3390/s17071627
    A mechanomyography muscle contraction (MC) sensor, affixed to the skin surface, was used to quantify muscle tension during repetitive functional electrical stimulation (FES)-evoked isometric rectus femoris contractions to fatigue in individuals with spinal cord injury (SCI). Nine persons with motor complete SCI were seated on a commercial muscle dynamometer that quantified peak torque and average torque outputs, while measurements from the MC sensor were simultaneously recorded. MC-sensor-predicted measures of dynamometer torques, including the signal peak (SP) and signal average (SA), were highly associated with isometric knee extension peak torque (SP: r = 0.91, p < 0.0001), and average torque (SA: r = 0.89, p < 0.0001), respectively. Bland-Altman (BA) analyses with Lin's concordance (ρC) revealed good association between MC-sensor-predicted peak muscle torques (SP; ρC = 0.91) and average muscle torques (SA; ρC = 0.89) with the equivalent dynamometer measures, over a range of FES current amplitudes. The relationship of dynamometer torques and predicted MC torques during repetitive FES-evoked muscle contraction to fatigue were moderately associated (SP: r = 0.80, p < 0.0001; SA: r = 0.77; p < 0.0001), with BA associations between the two devices fair-moderate (SP; ρC = 0.70: SA; ρC = 0.30). These findings demonstrated that a skin-surface muscle mechanomyography sensor was an accurate proxy for electrically-evoked muscle contraction torques when directly measured during isometric dynamometry in individuals with SCI. The novel application of the MC sensor during FES-evoked muscle contractions suggested its possible application for real-world tasks (e.g., prolonged sit-to-stand, stepping,) where muscle forces during fatiguing activities cannot be directly measured.
    Matched MeSH terms: Muscle, Skeletal
  4. Fulltext Targeting myomiRs by tocotrienol-rich fraction to promote myoblast differentiation
    Razak AM, Khor SC, Jaafar F, Karim NA, Makpol S
    Genes Nutr, 2018;13:31.
    PMID: 30519366 DOI: 10.1186/s12263-018-0618-2
    Background: Several muscle-specific microRNAs (myomiRs) are differentially expressed during cellular senescence. However, the role of dietary compounds on myomiRs remains elusive. This study aimed to elucidate the modulatory role of tocotrienol-rich fraction (TRF) on myomiRs and myogenic genes during differentiation of human myoblasts. Young and senescent human skeletal muscle myoblasts (HSMM) were treated with 50 μg/mL TRF for 24 h before and after inducing differentiation.

    Results: The fusion index and myotube surface area were higher (p 

    Matched MeSH terms: Muscle, Skeletal
  5. Fulltext Effects of releasing ankle joint during electrically evoked cycling in persons with motor complete spinal cord injury
    Hamdan PNF, Hamzaid NA, Hasnan N, Abd Razak NA, Razman R, Usman J
    Sci Rep, 2024 Mar 18;14(1):6451.
    PMID: 38499594 DOI: 10.1038/s41598-024-56955-w
    Literature has shown that simulated power production during conventional functional electrical stimulation (FES) cycling was improved by 14% by releasing the ankle joint from a fixed ankle setup and with the stimulation of the tibialis anterior and triceps surae. This study aims to investigate the effect of releasing the ankle joint on the pedal power production during FES cycling in persons with spinal cord injury (SCI). Seven persons with motor complete SCI participated in this study. All participants performed 1 min of fixed-ankle and 1 min of free-ankle FES cycling with two stimulation modes. In mode 1 participants performed FES-evoked cycling with the stimulation of quadriceps and hamstring muscles only (QH stimulation), while Mode 2 had stimulation of quadriceps, hamstring, tibialis anterior, and triceps surae muscles (QHT stimulation). The order of each trial was randomized in each participant. Free-ankle FES cycling offered greater ankle plantar- and dorsiflexion movement at specific slices of 20° crank angle intervals compared to fixed-ankle. There were significant differences in the mean and peak normalized pedal power outputs (POs) [F(1,500) = 14.03, p 
    Matched MeSH terms: Muscle, Skeletal
  6. Fulltext Mechanomyographic parameter extraction methods: an appraisal for clinical applications
    Ibitoye MO, Hamzaid NA, Zuniga JM, Hasnan N, Wahab AK
    Sensors (Basel), 2014;14(12):22940-70.
    PMID: 25479326 DOI: 10.3390/s141222940
    The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG) parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contraction have been evaluated in the light of the signal features. As a non-stationary signal that reflects several distinctive patterns of muscle actions, the illustrations obtained from the literature support the reliability of MMG in the analysis of muscles under voluntary and stimulus evoked contractions. An appraisal of the standard practice including the measurement theories of the methods used to extract parameters of the signal is vital to the application of the signal during experimental and clinical practices, especially in areas where electromyograms are contraindicated or have limited application. As we highlight the underpinning technical guidelines and domains where each method is well-suited, the limitations of the methods are also presented to position the state of the art in MMG parameters extraction, thus providing the theoretical framework for improvement on the current practices to widen the opportunity for new insights and discoveries. Since the signal modality has not been widely deployed due partly to the limited information extractable from the signals when compared with other classical techniques used to assess muscle performance, this survey is particularly relevant to the projected future of MMG applications in the realm of musculoskeletal assessments and in the real time detection of muscle activity.
    Matched MeSH terms: Muscle, Skeletal/physiopathology*
  7. Muscle synergies during incremental rowing VO2max test of collegiate rowers and untrained subjects
    Shaharudin S, Agrawal S
    J Sports Med Phys Fitness, 2016 Sep;56(9):980-9.
    PMID: 25732319
    BACKGROUND: The purpose of this study was to evaluate the muscle synergies during incremental rowing VO2 max Test of collegiate rowers and untrained subjects. As a power endurance sport, high aerobic capacity was one of the determinants of rowing performance. The modulation of muscle recruitment patterns following specific physiological demands was an indication of the robustness of muscle synergies composition which was overlooked in previous studies.

    METHODS: Ten male collegiate rowers and physically active untrained subjects were recruited. Muscle synergies were extracted from 16 rowing-specific muscles using Principal Component Analysis with varimax rotation. Incremental rowing VO2 max Test was performed on slides ergometer (SE). Rowing performance and physiological variables were analyzed.

    RESULTS: Rowers exerted greater power output, more energy expenditure and better rowing economy compared to untrained subjects. Rowers preferred to row slower with longer strokes compared to the untrained subjects. Three muscle synergies with high indices of similarity of waveform patterns were extracted in both groups. Significant association was found between muscle synergies and rowing economy.

    CONCLUSIONS: The findings of this study showed that muscle synergies were robust during aerobic-dominant activity for collegiate rowers and untrained subjects. Rowers and coaches could utilize the findings by emphasizing on muscle coordination training, which may enhance the rowing economy.

    Matched MeSH terms: Muscle, Skeletal/physiology*
  8. Role of nitric oxide in skeletal muscle glucose uptake during exercise
    Hong YH, Betik AC, McConell GK
    Exp Physiol, 2014 Dec 1;99(12):1569-73.
    PMID: 25192731 DOI: 10.1113/expphysiol.2014.079202
    Nitric oxide is produced within skeletal muscle fibres and has various functions in skeletal muscle. There is evidence that NO may be essential for normal increases in skeletal muscle glucose uptake during contraction/exercise. Although there have been some discrepant results, it has been consistently demonstrated that inhibition of NO synthase (NOS) attenuates the increase in skeletal muscle glucose uptake during contraction in mouse and rat muscle ex vivo, during in situ contraction in rats and during exercise in humans. The NO-mediated increase in skeletal muscle glucose uptake during contraction/exercise is probably due to the modulation of intramuscular signalling that ultimately increases glucose transporter 4 (GLUT4) translocation and is, surprisingly, independent of blood flow. In this review, we discuss the evidence for and against a role of NO in regulating skeletal muscle glucose uptake during contraction/exercise and outline the possible mechanism(s) involved. Emerging findings regarding the role of neuronal NOS mu (nNOSμ) in this process are also discussed.
    Matched MeSH terms: Muscle, Skeletal/metabolism*
  9. Analysis of crosstalk in the mechanomyographic signals generated by forearm muscles during different wrist postures
    Islam A, Sundaraj K, Ahmad RB, Sundaraj S, Ahamed NU, Ali MA
    Muscle Nerve, 2015 Jun;51(6):899-906.
    PMID: 25204740 DOI: 10.1002/mus.24454
    In this study, we analyzed the crosstalk in mechanomyographic (MMG) signals generated by the extensor digitorum (ED), extensor carpi ulnaris (ECU), and flexor carpi ulnaris (FCU) muscles of the forearm during wrist flexion (WF) and extension (WE) and radial (RD) and ulnar (UD) deviations.
    Matched MeSH terms: Muscle, Skeletal/physiopathology*
  10. Fulltext Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures
    Islam MA, Sundaraj K, Ahmad RB, Sundaraj S, Ahamed NU, Ali MA
    PLoS One, 2014;9(8):e104280.
    PMID: 25090008 DOI: 10.1371/journal.pone.0104280
    In mechanomyography (MMG), crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity.
    Matched MeSH terms: Muscle, Skeletal/physiology*
  11. Fulltext The effectiveness of FES-evoked EMG potentials to assess muscle force and fatigue in individuals with spinal cord injury
    Ibitoye MO, Estigoni EH, Hamzaid NA, Wahab AK, Davis GM
    Sensors (Basel), 2014;14(7):12598-622.
    PMID: 25025551 DOI: 10.3390/s140712598
    The evoked electromyographic signal (eEMG) potential is the standard index used to monitor both electrical changes within the motor unit during muscular activity and the electrical patterns during evoked contraction. However, technical and physiological limitations often preclude the acquisition and analysis of the signal especially during functional electrical stimulation (FES)-evoked contractions. Hence, an accurate quantification of the relationship between the eEMG potential and FES-evoked muscle response remains elusive and continues to attract the attention of researchers due to its potential application in the fields of biomechanics, muscle physiology, and rehabilitation science. We conducted a systematic review to examine the effectiveness of eEMG potentials to assess muscle force and fatigue, particularly as a biofeedback descriptor of FES-evoked contractions in individuals with spinal cord injury. At the outset, 2867 citations were identified and, finally, fifty-nine trials met the inclusion criteria. Four hypotheses were proposed and evaluated to inform this review. The results showed that eEMG is effective at quantifying muscle force and fatigue during isometric contraction, but may not be effective during dynamic contractions including cycling and stepping. Positive correlation of up to r = 0.90 (p < 0.05) between the decline in the peak-to-peak amplitude of the eEMG and the decline in the force output during fatiguing isometric contractions has been reported. In the available prediction models, the performance index of the eEMG signal to estimate the generated muscle force ranged from 3.8% to 34% for 18 s to 70 s ahead of the actual muscle force generation. The strength and inherent limitations of the eEMG signal to assess muscle force and fatigue were evident from our findings with implications in clinical management of spinal cord injury (SCI) population.
    Matched MeSH terms: Muscle, Skeletal/physiopathology*
  12. Effects of action observation on corticospinal excitability: Muscle specificity, direction, and timing of the mirror response
    Naish KR, Houston-Price C, Bremner AJ, Holmes NP
    Neuropsychologia, 2014 11;64:331-48.
    PMID: 25281883 DOI: 10.1016/j.neuropsychologia.2014.09.034
    Many human behaviours and pathologies have been attributed to the putative mirror neuron system, a neural system that is active during both the observation and execution of actions. While there are now a very large number of papers on the mirror neuron system, variations in the methods and analyses employed by researchers mean that the basic characteristics of the mirror response are not clear. This review focuses on three important aspects of the mirror response, as measured by modulations in corticospinal excitability: (1) muscle specificity; (2) direction; and (3) timing of modulation. We focus mainly on electromyographic (EMG) data gathered following single-pulse transcranial magnetic stimulation (TMS), because this method provides precise information regarding these three aspects of the response. Data from paired-pulse TMS paradigms and peripheral nerve stimulation (PNS) are also considered when we discuss the possible mechanisms underlying the mirror response. In this systematic review of the literature, we examine the findings of 85 TMS and PNS studies of the human mirror response, and consider the limitations and advantages of the different methodological approaches these have adopted in relation to discrepancies between their findings. We conclude by proposing a testable model of how action observation modulates corticospinal excitability in humans. Specifically, we propose that action observation elicits an early, non-specific facilitation of corticospinal excitability (at around 90ms from action onset), followed by a later modulation of activity specific to the muscles involved in the observed action (from around 200ms). Testing this model will greatly advance our understanding of the mirror mechanism and provide a more stable grounding on which to base inferences about its role in human behaviour.
    Matched MeSH terms: Muscle, Skeletal/physiology*
  13. Evaluation of repetitive isometric contractions on the heads of triceps brachii muscle during grip force exercise
    Ali MA, Sundaraj K, Ahmad RB, Ahamed NU, Islam MA, Sundaraj S
    Technol Health Care, 2014;22(4):617-25.
    PMID: 24990168 DOI: 10.3233/THC-140833
    Normally, surface electromyography electrodes are used to evaluate the activity of superficial muscles during various kinds of voluntary contractions of muscle fiber. The objective of the present study was to investigate the effect of repetitive isometric contractions on the three heads of the triceps brachii muscle during handgrip force exercise.
    Matched MeSH terms: Muscle, Skeletal/physiology
  14. Fulltext Vitamin E in sarcopenia: current evidences on its role in prevention and treatment
    Khor SC, Abdul Karim N, Ngah WZ, Yusof YA, Makpol S
    Oxid Med Cell Longev, 2014;2014:914853.
    PMID: 25097722 DOI: 10.1155/2014/914853
    Sarcopenia is a geriatric syndrome that is characterized by gradual loss of muscle mass and strength with increasing age. Although the underlying mechanism is still unknown, the contribution of increased oxidative stress in advanced age has been recognized as one of the risk factors of sarcopenia. Thus, eliminating reactive oxygen species (ROS) can be a strategy to combat sarcopenia. In this review, we discuss the potential role of vitamin E in the prevention and treatment of sarcopenia. Vitamin E is a lipid soluble vitamin, with potent antioxidant properties and current evidence suggesting a role in the modulation of signaling pathways. Previous studies have shown its possible beneficial effects on aging and age-related diseases. Although there are evidences suggesting an association between vitamin E and muscle health, they are still inconclusive compared to other more extensively studied chronic diseases such as neurodegenerative diseases and cardiovascular diseases. Therefore, we reviewed the role of vitamin E and its potential protective mechanisms on muscle health based on previous and current in vitro and in vivo studies.
    Matched MeSH terms: Muscle, Skeletal/metabolism
  15. Mechanomyography and muscle function assessment: a review of current state and prospects
    Ibitoye MO, Hamzaid NA, Zuniga JM, Abdul Wahab AK
    Clin Biomech (Bristol, Avon), 2014 Jun;29(6):691-704.
    PMID: 24856875 DOI: 10.1016/j.clinbiomech.2014.04.003
    Previous studies have explored to saturation the efficacy of the conventional signal (such as electromyogram) for muscle function assessment and found its clinical impact limited. Increasing demand for reliable muscle function assessment modalities continues to prompt further investigation into other complementary alternatives. Application of mechanomyographic signal to quantify muscle performance has been proposed due to its inherent mechanical nature and ability to assess muscle function non-invasively while preserving muscular neurophysiologic information. Mechanomyogram is gaining accelerated applications in evaluating the properties of muscle under voluntary and evoked muscle contraction with prospects in clinical practices. As a complementary modality and the mechanical counterpart to electromyogram; mechanomyogram has gained significant acceptance in analysis of isometric and dynamic muscle actions. Substantial studies have also documented the effectiveness of mechanomyographic signal to assess muscle performance but none involved comprehensive appraisal of the state of the art applications with highlights on the future prospect and potential integration into the clinical practices. Motivated by the dearth of such critical review, we assessed the literature to investigate its principle of acquisition, current applications, challenges and future directions. Based on our findings, the importance of rigorous scientific and clinical validation of the signal is highlighted. It is also evident that as a robust complement to electromyogram, mechanomyographic signal may possess unprecedented potentials and further investigation will be enlightening.
    Matched MeSH terms: Muscle, Skeletal/physiology*
  16. Olfactory ensheathing cells seeded muscle-stuffed vein as nerve conduit for peripheral nerve repair: a nerve conduction study
    Lokanathan Y, Ng MH, Hasan S, Ali A, Mahmod M, Htwe O, et al.
    J Biosci Bioeng, 2014 Aug;118(2):231-4.
    PMID: 24598302 DOI: 10.1016/j.jbiosc.2014.02.002
    We evaluated bridging of 15 mm nerve gap in rat sciatic nerve injury model with muscle-stuffed vein seeded with olfactory ensheathing cells as a substitute for nerve autograft. Neurophysiological recovery, as assessed by electrophysiological analysis was faster in the constructed biological nerve conduit compared to that of autograft.
    Matched MeSH terms: Muscle, Skeletal/pathology
  17. Fulltext Cross-talk in mechanomyographic signals from the forearm muscles during sub-maximal to maximal isometric grip force
    Islam MA, Sundaraj K, Ahmad RB, Sundaraj S, Ahamed NU, Ali MA
    PLoS One, 2014;9(5):e96628.
    PMID: 24802858 DOI: 10.1371/journal.pone.0096628
    This study aimed: i) to examine the relationship between the magnitude of cross-talk in mechanomyographic (MMG) signals generated by the extensor digitorum (ED), extensor carpi ulnaris (ECU), and flexor carpi ulnaris (FCU) muscles with the sub-maximal to maximal isometric grip force, and with the anthropometric parameters of the forearm, and ii) to quantify the distribution of the cross-talk in the MMG signal to determine if it appears due to the signal component of intramuscular pressure waves produced by the muscle fibers geometrical changes or due to the limb tremor.
    Matched MeSH terms: Muscle, Skeletal/physiology*
  18. Fulltext Sarcocystis nesbitti infection in human skeletal muscle: possible transmission from snakes
    Lau YL, Chang PY, Tan CT, Fong MY, Mahmud R, Wong KT
    Am J Trop Med Hyg, 2014 Feb;90(2):361-4.
    PMID: 24420776 DOI: 10.4269/ajtmh.12-0678
    Sarcocystis nesbitti is an intracellular protozoan parasite found as sarcocysts within muscle fibers of intermediate hosts (monkey and baboon). The definitive host is suspected to be the snake. We report two cases from a larger cohort of 89 patients who had fever, headache, and generalized myalgia after a trip to Pangkor Island, Malaysia. Sarcocysts were detected in skeletal muscle biopsy specimens by light and electron microscopy from these two patients. DNA sequencing based on the 18S ribosomal DNA region identified the Sarcocystis species as S. nesbitti. We also identified S. nesbitti sequences in the stools of a snake (Naja naja). Phylogenetic analysis showed that these sequences form a cluster with most of the other known Sarcocystis species for which the snake is a definitive host. We believe these two patients were likely to have symptomatic acute muscular sarcocystosis after S. nesbitti infection that may have originated from snakes.
    Matched MeSH terms: Muscle, Skeletal/parasitology*
  19. Fulltext The effect of relaxin on the musculoskeletal system
    Dehghan F, Haerian BS, Muniandy S, Yusof A, Dragoo JL, Salleh N
    Scand J Med Sci Sports, 2014 Aug;24(4):e220-9.
    PMID: 24283470 DOI: 10.1111/sms.12149
    Relaxin is a hormone structurally related to insulin and insulin-like growth factor, which exerts its regulatory effect on the musculoskeletal and other systems through binding to its receptor in various tissues, mediated by different signaling pathways. Relaxin alters the properties of cartilage and tendon by activating collagenase. This hormone is also involved in bone remodeling and healing of injured ligaments and skeletal muscle. In this review, we have summarized the literature on the effect of relaxin in musculoskeletal system to provide a broad perspective for future studies in this field.
    Matched MeSH terms: Muscle, Skeletal/physiology*
  20. Fulltext Surface electromyography signal processing and classification techniques
    Chowdhury RH, Reaz MB, Ali MA, Bakar AA, Chellappan K, Chang TG
    Sensors (Basel), 2013;13(9):12431-66.
    PMID: 24048337 DOI: 10.3390/s130912431
    Electromyography (EMG) signals are becoming increasingly important in many applications, including clinical/biomedical, prosthesis or rehabilitation devices, human machine interactions, and more. However, noisy EMG signals are the major hurdles to be overcome in order to achieve improved performance in the above applications. Detection, processing and classification analysis in electromyography (EMG) is very desirable because it allows a more standardized and precise evaluation of the neurophysiological, rehabitational and assistive technological findings. This paper reviews two prominent areas; first: the pre-processing method for eliminating possible artifacts via appropriate preparation at the time of recording EMG signals, and second: a brief explanation of the different methods for processing and classifying EMG signals. This study then compares the numerous methods of analyzing EMG signals, in terms of their performance. The crux of this paper is to review the most recent developments and research studies related to the issues mentioned above.
    Matched MeSH terms: Muscle, Skeletal/physiology*
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