Displaying publications 61 - 80 of 127 in total

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  1. Lin PC, Fang JC, Lin JW, Tran XV, Ching YC
    Materials (Basel), 2020 Sep 19;13(18).
    PMID: 32961763 DOI: 10.3390/ma13184170
    Effects of processing parameters on preheated (heat-assisted) clinching process to join aluminum alloy 5052-H32 (AA5052) and thermoplastic carbon-fiber-reinforced-plastic (TP-CFRP) sheets for cross-tension (CT) specimens were first studied. Preheating was critical since brittle TP-CFRP could be softened to avoid fracturing or cracking during clinching process. Four processing parameters, including punching force, die depth, heating mode, and heating temperature, were considered. Quasi-static tests and microscope observations were taken to evaluate AA5052/TP-CFRP clinch joints in CT specimens and determine appropriate processing parameters for fatigue tests. Finally, fatigue data and failure mode of clinch joints in CT specimens were obtained and discussed.
    Matched MeSH terms: Fatigue
  2. James C, Girard O
    PMID: 33345057 DOI: 10.3389/fspor.2020.00066
    Repeated-sprint training in hypoxia (RSH) studies conducted "in-season" are scarce. This study investigated the effect of discontinuous, running-based RSH, on repeated-sprint treadmill performance in hypoxia in a team sport cohort, prior to international competition. Over a 6-week "in-season" period, 11 elite male players (Malaysia national team) completed eight multi-set RSH sessions on a non-motorized treadmill in a normobaric hypoxic chamber (FiO2 = 13.8%). Three testing sessions (Sessions 1, 5, and 8), involved three sets of 5 × 8-s sprints, with 52-s recovery between sprints and 4-5 min between sets. Training sessions (Sessions 2, 3, 4, 6, and 7) consisted of four to five sets of 4-5 × 8-s sprints. During testing sessions, maximum sprinting speed was recorded for each sprint with values averaged for each set. For each set, a peak speed and fatigue index were calculated. Data were compared using two-way repeated measures ANOVA (sessions × sets). Average speed per set increased between testing sessions (p = 0.001,


    η


    p


    2


    = 0.49), with higher values in Session 8 (25.1 ± 0.9 km.h-1, +4 ± 3%, p = 0.005), but not Session 5 (24.8 ± 1.0 km.h-1, +3 ± 3%, p = 0.405), vs. Session 1 (24.2 ± 1.5 km.h-1). Peak sprinting speed in each set also increased across testing sessions (p = 0.008,


    η


    p


    2


    = 0.382), with Session 8 (26.5 ± 1.1 km.h-1) higher than Session 5 (25.8 ± 1.0 km.h-1, +1 ± 4%, p = 0.06) and Session 1 (25.7 ± 1.5 km.h-1, +4 ± 4%, p = 0.034). Fatigue index differed between sessions (p = 0.04,


    η


    p


    2


    = 0.331, Session 1; -6.8 ± 4.8%, Session 5; -3.8 ± 2%, Session 8; -5.3 ± 2.6%). In international field hockey players, a 6-week in-season RSH program improved average and peak, repeated treadmill sprint speeds following eight, but not five sessions.
    Matched MeSH terms: Fatigue
  3. Metastasio A, Prevete E, Singh D, Grundmann O, Prozialeck WC, Veltri C, et al.
    Front Psychiatry, 2020;11:594816.
    PMID: 33329145 DOI: 10.3389/fpsyt.2020.594816
    Among the symptoms of COVID-19 fever, general malaise, pain and aches, myalgia, fatigue, and headache can affect the quality of life of patients, even after the end of the acute phase of the infection and can be long lasting. The current treatment of these symptoms, also because COVID-19 patients have been asked not to use non-steroidal anti-inflammatory drugs (NSAIDs), in particular ibuprofen are often unsatisfactory. Among the above mentioned symptoms malaise and fatigue seem the most difficult to treat. In this case report we describe the use of kratom (Mitragyna speciosa) by a patient with confirmed COVID-19 infection. What we observed was a fast and sustained relieve of the above mentioned symptoms.
    Matched MeSH terms: Fatigue
  4. Adnan R, Van Oosterwijck J, Danneels L, Willems T, Meeus M, Crombez G, et al.
    J Back Musculoskelet Rehabil, 2020;33(6):919-930.
    PMID: 33016899 DOI: 10.3233/BMR-191548
    BACKGROUND: Differences in pain processing, muscle structure and function have been reported in patients with low back pain (LBP) with different grades of pain chronicity.

    OBJECTIVE: The present study aims to examine differences in psychological factors, disability and subjective fatigue between subgroups of LBP based on their chronification grade.

    METHODS: Twenty-one healthy controls (HC) and 54 LBP patients (categorized based on the grades of chronicity into recurrent LBP (RLBP), non-continuous chronic LBP (CLBP), or continuous (CLBP)) filled out a set of self-reporting questionnaires.

    RESULTS: The Hospital Anxiety and Depression Scale (HADS) and Multidimensional Pain Inventory (MPI) scores indicated that anxiety, pain severity, pain interference and affective distress were lower in HC and RLBP compared to non-continuous CLBP. Anxiety scores were higher in non-continuous CLBP compared to RLBP, continuous CLBP and HC. The Pain Catastrophizing Scale for Helplessness (PSCH) was higher in non-continuous CLBP compared to HC. The Survey of Pain Attitudes (SOPA) showed no differences in adaptive and maladaptive behaviors across the groups. The Pain Disability Index (PDI) measured a higher disability in both CLBP groups compared to HC. Moreover, the Rolland Morris Disability Questionnaire (RMDQ) showed higher levels of disability in continuous CLBP compared to non-continuous CLBP, RLBP and HC. The Checklist Individual Strength (CIS) revealed that patients with non-continuous CLBP were affected to a higher extent by severe fatigue compared to continuous CLBP, RLBP and HC (subjective fatigue, concentration and physical activity). For all tests, a significance level of 0.05 was used.

    CONCLUSIONS: RLBP patients are more disabled than HC, but have a tendency towards a general positive psychological state of mind. Non-continuous CLBP patients would most likely present a negative psychological mindset, become more disabled and have prolonged fatigue complaints. Finally, the continuous CLBP patients are characterized by more negative attitudes and believes on pain, enhanced disability and interference of pain in their daily lives.

    Matched MeSH terms: Fatigue/diagnosis*; Fatigue/physiopathology; Fatigue/psychology
  5. Amirah Zahiran, Fara Liana Zainuddin, Shazlin Shaharudin
    MyJurnal
    Introduction: In this study, we evaluated the kinematics of lower limb during early and late phases of 2km time trial on stationary rowing ergometer among Malaysian male rowers. Methods: Seventeen national-level rowers voluntari- ly participated. Three dimensional lower limb kinematics data were collected to represent the first 400 m (i.e., early) and the last 400m (i.e., late) phases of 2km time trial on a stationary ergometer. The kinematics data at sagittal, frontal and transverse planes of dominant leg during catch and finish positions were compared across early and late phases of the time trial using paired T-test. Results: The kinematics of lower limb joints at three planes were not significantly different during early versus late phases of 2km time trial among male senior rowers except for hip flexion at finish (p=0.411), ankle rotation at catch (p=0.779) and ankle abduction at finish (p=0.677). Conclusion: Lower limb kine- matics particularly the hip flexion, ankle rotation and ankle abduction may change across early and late phases of 2km time trial due to fatigue. Coaches and rowers should monitor these motions during fatiguing rowing piece and develop necessary injury prevention measures.
    Matched MeSH terms: Fatigue
  6. Thulasi, M., Rosnah Md Yusuff, Norzima bt Zulkifli, Perimal, Enoch Kumar
    MyJurnal
    Upper extremity musculoskeletal disorder (MSD) has become a common problem among office workers in Malaysia. Studies have shown that an appropriate work-rest schedule can reduce fatigue and MSDs among office workers. In Malaysia, there has been an increase in the occurrence of MSDs, especially in work that require intensive computer use. Operators who used computers continuously for more than 4 hours a day have shown to develop CTDs. Studies on the effect of break time on the performance of office workers in Malaysia are still lacking. As such this study was aimed to evaluate effect of work rest schedule on the discomfort, performance and muscular load levels of computer users in Malaysia. The effect of break time starting with no break, one minute and 30 seconds break interval were carried out on the 15 subjects. EMG was measured for each task given. Performance which was calculated by multiplying speed and accuracy (WPM) showed 30 seconds break was 13.5% higher than 1 minute break and 20.14% higher than schedule with no break. EMG analyses showed 30 seconds have lowest mean AEMG which was 0.035 for flexor carpi ulnaris and 0.0331 for radialis muscles. It also recorded least discomfort scale for upper extremity muscles compared to the other two schedules. This study showed that more frequent microbreaks can improve performance of office workers and reduce MSD problem from occurring.
    Matched MeSH terms: Fatigue
  7. Lee HJ, Pok LSL, Ng CM, Yahya F, Sockalingam S, Tee YC, et al.
    Int J Rheum Dis, 2020 Aug;23(8):1088-1093.
    PMID: 32597545 DOI: 10.1111/1756-185X.13897
    INTRODUCTION: Fatigue is an important yet infrequently evaluated component in patients with rheumatoid arthritis (RA) and may have a major impact on quality of life.

    OBJECTIVES: To evaluate fatigue, identify factors associated with fatigue and assess the effect of fatigue on health-related quality of life (HRQoL) in a multi-ethnic cohort of RA patients.

    METHODS: A cross-sectional study was performed in patients who fulfilled European League Against Rheumatism/ American College of Rheumatology 2010 criteria for RA. Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F) questionnaire was used to assess fatigue. Potential factors for fatigue were categorized into RA-related (gender, seropositivity [rheumatoid factor and/or anti-citrullinated protein antibody], disease duration, visual analog scale pain score, Disease Activity Score of 28 joints - erythrocyte sedimentation rate [DAS28-ESR], ESR, hemoglobin level, functional disability [Health Assessment Questionnaire - Disability Index, HAQ-DI score], EQ-5D-3L, concomitant prednisolone use and number of conventional synthetic disease-modifying anti-rheumatic drugs [csDMARDs] used) and non-RA-related (age, body mass index, ethnicity and number of co-morbidities).

    RESULTS: A total of 214 patients (86.9% female) were included; the median age was 62 (25-91) years and 67.3% were seropositive. Seventy-six (33.5%) patients had moderate disease activity, 12 (5.6%) had high disease activity and 152 (71%) patients had mild difficulties to moderate disability HAQ-DI scores. Median of total FACIT-F score was 113.2 (36.3-160.0). Joint factors of younger age, longer disease duration, higher HAQ score (increased functional disability), and lower EQ-5D (poorer HRQoL) were significantly associated with higher levels of fatigue (all P 

    Matched MeSH terms: Fatigue/diagnosis*; Fatigue/ethnology; Fatigue/physiopathology
  8. Nadarajah M, Mazlan M, Abdul-Latif L, Goh HT
    Eur J Phys Rehabil Med, 2017 Oct;53(5):703-709.
    PMID: 27768012 DOI: 10.23736/S1973-9087.16.04388-4
    BACKGROUND: Post-stroke fatigue (PSF) is a common complaint among stroke survivors and has significant impacts on recovery and quality of life. Limited tools that measure fatigue have been validated in stroke.
    AIM: The purpose of this study was to determine the psychometric properties of Fatigue Severity Scale (FSS) in patients with stroke.
    DESIGN: Cross-sectional study.
    SETTING: Teaching hospital outpatient setting.
    POPULATION: Fifty healthy controls (mean age 61.1±7.4 years; 22 males) and 50 patients with stroke (mean age 63.6±10.3 years; 34 males).
    METHODS: FSS was administered twice approximately a week apart through face-to-face interview. In addition, we measured fatigue with Visual Analogue Scale - Fatigue (VAS-F) and Short-Form Health Survey 36 version 2 vitality scale. We used Cronbach alpha to determine internal consistency of FSS. Reliability and validity of FSS were determined by intraclass correlation coefficient (ICC) and Spearman correlation coefficient (r).
    RESULTS: FSS showed excellent internal consistency for both stroke and healthy groups (Cronbach's alpha >0.90). FSS had excellent test-retest reliability for stroke patients and healthy controls (ICC=0.93 and ICC=0.90, respectively). The scale demonstrated good concurrent validity with VAS-Fatigue (all r>.60) and a moderate validity with the SF36-vitality scale. Furthermore, FSS was sensitive to distinguish fatigue in stroke from the healthy controls (P<0.01).
    CONCLUSIONS: FSS has excellent internal consistency, test-retest reliability and good concurrent validity with VAS-F for both groups.
    CLINICAL REHABILITATION IMPACT: This study provides evidence that FSS is a reliable and valid tool to measure post-stroke fatigue and is readily to be used in clinical settings.

    Study site: Teaching hospital outpatient setting
    Matched MeSH terms: Fatigue Syndrome, Chronic/diagnosis*; Fatigue Syndrome, Chronic/etiology; Fatigue Syndrome, Chronic/epidemiology
  9. Noor'Ain Azizan, Seri Rahayu Kamat, Nur Syafiqah Rayme, Ruzy Haryati Hambali
    MyJurnal
    Repetitive movement can lead to the pain muscle, nerves, and tendons that cause by
    repetitive overuse of working task. The muscle will fatigue due to; repetitive
    movement, force that been applied, posture during working and duration of working.
    The stress level during working can influent the energy performance usage during
    working. The aim of this paper is to analyse the influence of heart rate and muscle
    activity of workers in composite manufacturing towards muscle fatigue. The data was
    collected for a worker in hand layup department and the Qualitative method was used
    in a way to investigate the working load and level of pain received by their body. Then,
    the Qualitative data was sorted and the respondent proceeded for a Quantitative
    method which involves muscle activity analysis and heart rate analysis. The tools that
    were used to conduct these experiments were surface electromyography (sEMG),
    Wristwatch with chest strap and perceived stress scale (PSS). The experimentation
    used to calculate the average reading of heart rate and muscle activity during working
    and detect the duration the muscle to start fatigue. Moreover, this paper analysed the
    relationship between heart rate and muscle activity through the duration of working.
    As an overall finding of this research, it was shown that the heart rate of the workers
    influence the muscle activity of workers and has high potential relationship to the
    fatigue of muscles of the workers in the layup department.
    Matched MeSH terms: Muscle Fatigue
  10. Mohd Safee MK, Abu Osman NA
    Occup Ther Int, 2021;2021:4357473.
    PMID: 34707468 DOI: 10.1155/2021/4357473
    Muscle fatigue is a decline in muscle maximum force during contraction and can influence the fall risk among people. This study is aimed at identifying the effect of fatigue on prospective fall risk in transfemoral amputees (TFA). Fourteen subjects were involved in this study with TFA (34.7 ± 8.1 yrs, n = 7) and normal subjects (31.1 ± 7.4 yrs, n = 7). Fatigue of lower limb muscles was induced with the fatigue protocol. Subjects were tested prefatigue and postfatigue using the standardized fall risk assessment. All results were calculated and compared between pre- and postfatigue to identify fatigue's effect on both groups of subjects. The results showed that the fall risk increased significantly during pre- and postfatigue for TFA (p = 0.018), while there were no significant differences in normal subjects (p = 0.149). Meanwhile, the fall risk between TFA and normal subjects for prefatigue (p = 0.082) and postfatigue (p = 0.084) also showed no significant differences. The percentage (%) of increased fall risk for TFA was 19.2% compared to normal subjects only 16.7%. However, 61.4% increased of % fall risk in TFA after fatigue by using the baseline of the normal subject as the normalized % of fall risk. The increasing fall risks for TFA after fatigue are three times higher than the potential fall risk in normal subjects. The result indicates that they need to perform more precautions while prolonging lower limb activities. These results showed the implications of fatigue that can increase the fall risk due to muscle fatigue from repetitive and prolonged activities. Therefore, rehabilitation programs can be done very safely and precisely so that therapists can pursue fitness without aggravating existing injuries.
    Matched MeSH terms: Muscle Fatigue
  11. Mohamad Ismail MR, Lam CK, Sundaraj K, Rahiman MHF
    J Musculoskelet Neuronal Interact, 2021 12 01;21(4):481-494.
    PMID: 34854387
    OBJECTIVE: This paper presents the analyses of the fatigue effect on the cross-talk in mechanomyography (MMG) signals of extensor and flexor forearm muscles during pre- and post-fatigue maximum voluntary isometric contraction (MVIC).

    METHODS: Twenty male participants performed repetitive submaximal (60% MVIC) grip muscle contractions to induce muscle fatigue and the results were analyzed during the pre- and post-fatigue MVIC. MMG signals were recorded on the extensor digitorum (ED), extensor carpi radialis longus (ECRL), flexor digitorum superficialis (FDS) and flexor carpi radialis (FCR) muscles. The cross-correlation coefficient was used to quantify the cross-talk values in forearm muscle pairs (MP1, MP2, MP3, MP4, MP5 and MP6). In addition, the MMG RMS and MMG MPF were calculated to determine force production and muscle fatigue level, respectively.

    RESULTS: The fatigue effect significantly increased the cross-talk values in forearm muscle pairs except for MP2 and MP6. While the MMG RMS and MMG MPF significantly decreased (p<0.05) based on the examination of the mean differences from pre- and post-fatigue MVIC.

    CONCLUSION: The presented results can be used as a reference for further investigation of cross-talk on the fatigue assessment of extensor and flexor muscles' mechanic.

    Matched MeSH terms: Muscle Fatigue
  12. 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 Fatigue
  13. 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 Fatigue*
  14. Justine M, Manaf H, Sulaiman A, Razi S, Alias HA
    Biomed Res Int, 2014;2014:640321.
    PMID: 24977154 DOI: 10.1155/2014/640321
    This study compares energy expenditure (EE), gait parameters (GP), and level of fatigue (LOF) between 5-minute walking with sharp turning (ST) and corner turning (CT). Data were obtained from 29 community-dwelling elderly (mean age, 62.7 ± 3.54 years). For 5 minutes, in ST task, participants walked on a 3-meter pathway with 2 cones placed at each end (180° turning), while in CT task, participants walked on a 6-meter pathway with 4 cones placed at 4 corners (90° turning). The physiological cost index, pedometer, and 10-point Modified Borg Dyspnoea Scale were used to measure EE (beats/min), GP (no of steps), and LOF, respectively. Data were analyzed by using independent t-tests. EE during ST (0.62 ± 0.21 beats/min) was significantly higher than CT (0.48 ± 0.17 beats/min) (P < 0.05). GP (434 ± 92.93 steps) and LOF (1.40 ± 1.11) in ST were found to be lower compared to GP (463 ± 92.18 steps) and LOF (1.54 ± 1.34) in CT (All, P > 0.05). Higher EE in ST could be due to the difficulty in changing to a 180° direction, which may involve agility and different turning strategies (step-turn or pivot-turn) to adjust the posture carefully. In CT, participants could choose a step-turn strategy to change to a 90° direction, which was less challenging to postural control.
    Matched MeSH terms: Fatigue/physiopathology*
  15. Naharudin MN, Yusof A
    PLoS One, 2013;8(10):e77290.
    PMID: 24204790 DOI: 10.1371/journal.pone.0077290
    BACKGROUND: Since hypohydration commonly occurs in sports, studies on anaerobic exercise performance under this condition have been extensively carried out. When describing anaerobic performance, authors usually refer to a drop in anaerobic performance as fatigue index (FI) which is conventionally calculated using peak and low power data points. Meanwhile, another possible method in explaining anaerobic fatigue is using the rate constant which is derived from the exponential decline of power output known as fatigue rate (FR). Few studies have demonstrated that there was no change in anaerobic performance under mild hypohydrations.

    PURPOSE: This study aimed to compare the kinetics of power output using FI and FR of an anaerobic performance (Wingate test) under 2, 3 and 4% state of hypohydrations.

    METHOD: Thirty two collegiate cyclists (age = 22 ± 2 years; body weight = 71.45 ± 3.43 kg; height = 173.23 ± 0.04 cm) were matched using their baseline anaerobic peak power (APP) then randomly divided into 4 groups of EU (euhydrated), 2H, 3H and 4H respectively.

    RESULTS: As expected the, FI, APP, anaerobic lower power (ALP) and rating of perceived exertion (RPE) did not show significant differences between and within the groups. However, the FR in 3H (0.018 ± 0.005 s(-1)) and 4H (0.019 ± 0.010 s(-1)) were significantly lower than EU (0.033 ± 0.012 s(-1)). Post-test FR also showed significant reduction in 3H and 4H compared to their pre-test values (p<0.05).

    CONCLUSION: Despite the lack of changes in APP and RPE, subjects in 3H and 4H showed evidence of lower reduction of power output over time. The findings support earlier reports which showed no change in anaerobic performance under mild hypohydrations. The relatively lower FR suggests higher drive in maintaining power output under hypohydrations of 3 and 4% body weight.

    Matched MeSH terms: Fatigue/psychology*
  16. Ajit Singh DK, Bailey M, Lee R
    Muscle Nerve, 2011 Jul;44(1):74-9.
    PMID: 21488056 DOI: 10.1002/mus.21998
    Loss of lumbar extensor muscle strength and fatigue resistance may contribute to functional disability.
    Matched MeSH terms: Muscle Fatigue/physiology*
  17. Naeem J, Hamzaid NA, Islam MA, Azman AW, Bijak M
    Med Biol Eng Comput, 2019 Jun;57(6):1199-1211.
    PMID: 30687901 DOI: 10.1007/s11517-019-01949-4
    Patients with spinal cord injury (SCI) benefit from muscle training with functional electrical stimulation (FES). For safety reasons and to optimize training outcome, the fatigue state of the target muscle must be monitored. Detection of muscle fatigue from mel frequency cepstral coefficient (MFCC) feature of mechanomyographic (MMG) signal using support vector machine (SVM) classifier is a promising new approach. Five individuals with SCI performed FES cycling exercises for 30 min. MMG signals were recorded on the quadriceps muscle group (rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM)) and categorized into non-fatigued and fatigued muscle contractions for the first and last 10 min of the cycling session. For each subject, a total of 1800 contraction-related MMG signals were used to train the SVM classifier and another 300 signals were used for testing. The average classification accuracy (4-fold) of non-fatigued and fatigued state was 90.7% using MFCC feature, 74.5% using root mean square (RMS), and 88.8% with combined MFCC and RMS features. Inter-subject prediction accuracy suggested training and testing data to be based on a particular subject or large collection of subjects to improve fatigue prediction capacity. Graphical abstract ᅟ.
    Matched MeSH terms: Muscle Fatigue/physiology*
  18. Khong TK, Selvanayagam V, Yusof A
    Eur J Sport Sci, 2021 Feb;21(2):224-230.
    PMID: 32056510 DOI: 10.1080/17461391.2020.1730980
    Carbohydrate (CHO) mouth rinse has been shown to improve endurance performance and maintain the central drive of contracting muscles. Salt (NaCl) mouth rinse solution, often used in dentistry to desensitise the oral cavity to pain, could also activate cortical areas of the brain. Hence, the objective of this preliminary study was to investigate whether CHO (glucose) and NaCl mouth rinses could attenuate the reduction in maximum voluntary contraction (MVC) and sustained MVC (sMVC) following an endurance exercise (30-minute cycling at 70% VO2max). Ten subjects (male, age: 22 ± 1 years, weight: 65.3 ± 12.4 kg, height: 164.5 ± 7.5 cm, VO2max: 48.3 ± 6.1 mL kg-1 min-1) completed three trials of 30-minute cycling exercise. In a randomised cross-over study, in each trial, the participants rinsed using either water, 6% glucose, or 6% NaCl solution for 5 s immediately prior to and every 10 min during the cycling exercise. The MVC and sMVC were measured pre and post cycling. Analysis of variance showed significant interaction and time effects for MVC, while for sMVC there was a significant interaction with time and group effects. Both MVC and sMVC were higher post cycling in the glucose and NaCl groups compared to the water group, which suggests that activation of glucose and NaCl oral receptors could better preserve post-exercise force production. This is the first study to show that NaCl mouth rinse can produce a comparable effect on glucose. Hence, mouth rinses may be able to activate other distinct pathways that could attenuate fatigue.
    Matched MeSH terms: Muscle Fatigue/drug effects*
  19. Lonsdale KA, Abadi FH
    Med Probl Perform Art, 2018 09;33(3):191-197.
    PMID: 30204825 DOI: 10.21091/mppa.2018.3027
    While numerous studies have investigated associations between Ramadan fasting and sports performance, as well as general health, little is known about the experiences of musicians who play while fasting. This exploratory case study aimed to gain a better understanding of the experiences of tertiary-level woodwind players who practice, rehearse, and perform while fasting. Sixteen undergraduate woodwind players from two Malaysian university music faculties completed an 11-item questionnaire, as well as a 7-day food and playing diary, which formed the basis for a semi-structured interview. Their experiences were compared with previous studies of fasting athletes. Many participants stated that practicing from noon to 3:00 pm was difficult due to feeling thirsty, hungry, tired, and exhausted, with some experiencing a dry mouth and/or lips. By 3:00 to 6:00 pm, some had difficulty focusing and felt tired, dizzy, or lacked energy to practice. Many felt more comfortable playing after breaking the fast or after eating sahur. The majority experienced positive impacts such as increased focus and efficiency while practicing. This study suggests that fasting woodwind players would benefit from practicing in the morning and after sunset, limiting their practice time in the afternoon, not skipping sahur, and ensuring adequate hydration during sunset and sunrise.
    Matched MeSH terms: Fatigue/physiopathology*
  20. Rahman IA, Mohamad N, Rohani JM, Zein RM
    Ind Health, 2018 Nov 21;56(6):492-499.
    PMID: 30210096 DOI: 10.2486/indhealth.2018-0043
    Prolonged standing can cause discomfort on the body of the workers and can lead to injury and occupational disease. One of the ergonomic intervention is through improving the work-rest scheduling. The purpose of this study are to identify the fatigue level from the perception of the worker and to investigate the impact of the work-rest scheduling to the standing workers for 12 h working time with a different gender. This study involved two methods which are self-assessment of the worker and direct measurement by using electromyography (EMG). For self-assessment, 80 workers have been interviewed using questionnaire in order to identify the fatigue level. For direct measurement, EMG was attached to the 15 selected workers at their respective leg and lower back to analyse the muscle efforts. In terms of perception, the results show the discomfort and fatigue level at the lower body region in the following order as foot ankle, lower back and leg. There is a significant difference between gender on discomfort pain for foot ankle and leg. The results show short frequent break by 10 min can reduce the fatigue at the leg and infrequent long break is preferable in order to reduce the fatigue at the lower back. In conclusion, it was found that prolonged standing affect the muscle fatigue and discomfort especially lower extremities such as foot ankle, lower back and leg. Besides that, different type of work rest scheduling and gender have significant result towards the muscle fatigue development.
    Matched MeSH terms: Muscle Fatigue/physiology*
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