Subjective Sensation Of Fatigue Research Articles

Application of indicators associated with mental fatigue in sanitary personnel from Heroes del Moncada Polyclinic in Cárdenas municipality, Cuba

Healthcare professionals undergo frequent job stress due to exposure to high cognitive demands. The present research was carried out at the "Héroes del Moncada'' polyclinic in the municipality of Cárdenas, Matanzas. The objective is to apply indicators associated to mental fatigue. The indicators applied are: Simple Reaction Time and Yoshitake Test. Statgraphic Centurion 15.0 software is used as a tool for information processing. The results of the research obtained in this study show significant differences between before and after in some of the indicators applied, which evidences the presence of mental workload at the end of the working day. When applying the Yoshitake Test after finishing the assigned activity, all the health personnel of the study sample manifested the presence of subjective sensation of fatigue, highlighting both physical and mental fatigue.

Cognitive Fatigability, not Fatigue predicts employment status in patients with MS three months after rehabilitation

Background: Fatigue is potentially the most important factor causing unemployment in people with Multiple Sclerosis (PwMS). Widely accepted is a discrimination between fatigue as subjective sensation and fatigability as objective measure of change in performance. The aim of this study was to identify, whether cognitive fatigue or cognitive fatigability is a better predictor for employment status three months after discharge from a neurological rehabilitation center. Methods: 64 PwMS (mean age 48.9, 43 females, mean time since diagnosis 14.7 years, median Expanded Disability Status Scale (EDSS) 3.8), complaining of fatigue and reporting difficulties with their working capacity, participated in a cognitive loading task during inpatient rehabilitation. Reaction time performance was measured using a standardized alertness test (TAP-M). Tonic alertness was measured at 8 a.m., 11 a.m. and 2 p.m. Patients worked on a standardized test battery during the morning and after lunch to induce fatigability. All of them completed the Fatigue Scale for Motor and Cognition (FSMC), a standardized questionnaire to rate the trait component of cognitive and motor fatigue. Their employment status was rated within a standardized interview by phone three months after discharge from the clinic. Results: Mean cognitive fatigue according to the FSMC was 38.9 ± 7.4 and mean motor fatigue 41.0 ± 5.6, indicating severe cognitive and motor fatigue. 15 (88%) of 17 patients working fulltime had severe fatigue according to the FSMC. The cognitive subscale of the FSMC (“FSMC cognition”) did not correlate (rs = -.084, p = .512) and the motor subscale of the FSMC (“FSMC motor”) correlated rather weakly but not significantly (rs= -.220, p = .080) with the employment status. In contrast, there was a significant and medium correlation between alertness at 8 a.m. (alertness1) and employment status (rs = -.304, p = .014). Ordered logistic regression revealed that only alertness1 and the alertness difference between afternoon and noon (alertness difference32) predicted significantly the employment status. The FSMC motor and cognition subscales had no predictive value for employment. Conclusion: Cognitive fatigability (tonic alertness at 8 a.m. or increase of reaction time during the afternoon) is more adequate to predict employment status in PwMS three months after discharge from the clinic than the subjective sensation of fatigue as determined by the FSMC.

INTER SEASON PHYSIOLOGICAL CONTROL OF THE BRAZILIAN BEACH HANDBALL TEAM

ABSTRACT Introduction: The Brazilian national women's beach handball team traditionally holds intense pre-competition training with several daily sessions in the weeks before major matches. This can cause excessive physical strain, but physiological monitoring can guide the coaching staff to modulate the training load, preventing this excessive strain. Objective: To monitor the physiological responses of members of the Brazilian national women's beach handball team in a pre-competition training program with loads modulated according to individual physiological response. Methods: Seventeen athletes (27.1 ± 3.8 years) were assessed before the start of the pre-competition training period (E1), on Day 8 (E2) and Day 18 (E3). Blood samples were taken for subsequent analysis of muscular damage markers (creatine kinase (CK) and lactate dehydrogenase (LDH)). An ECG test was performed to assess cardiac autonomic modulation (CAM), and the Profile of Mood States (POMS) questionnaire was applied to assess mood. The results were reported to the coaching staff, who made training adjustments according to the individual status of each athlete. Results: CK increased significantly from E1 to E2 (131.1 ± 80.9 vs 212.9 ± 131.7) and remained unchanged (212.9 ± 185.6) up to E3, while LDH was significantly reduced from E2 to E3 (590.7 ± 120.2 vs 457.8 ± 86.6), finishing the pre-competition training program with values similar to E1 (512.7 ± 190.6). The only change noted was the subjective sensation of fatigue from the POMS questionnaire that was significantly higher in E2 (4.82 ± 4.05) and E3 (5.5 ± 4.8) compared to E1 (2.06 ± 2.61), but no changes in total mood disturbance were detected in this instrument. Conclusion: With the modulation of training loads based on results of physiological tests, the members of the Brazilian national women's beach handball team responded in a physiologically adequate manner, even when faced with a sudden increase in training load for 18 consecutive days. Level of evidence III; Diagnostic study-investigation of a diagnostic test.

Prueba de caminata de carga progresiva (Incremental Shuttle Walking Test) en niños sanos

Background: The “incremental shuttle walking test” (ISWT) is an incremental test that allows the functional evaluation of respiratory diseases. It shows a greater correlation between distance walked and the maximum O2 uptake compared to the six-minute walking test. Presently we do not have reference values in Chilean pediatric population. Objective: To know the distance walked by children in the test. Material and Method: This was a correlational descriptive study. The final sample consisted of 60 subjects (35 boys and 25 girls) randomly selected from an age range from 10 to 14 years-old. During the test, walked distance (WD) in meters, basal and final heart rate (HR), dyspnea, subjective sensation of fatigue (SSF), gender, weight (kg), height (m) and cardiac response to exercise (CRE) were recorded. Descriptive statistics were performed in both series followed by a t-test to look for differences among genders. Pearson's correlation coefficient was used to verify the correlation between variables. Results were expressed as mean ± SD. Results: Mean of WD in all the 60 children together was 596.2 ± 178.7 m; in average WD in girls series was 531.6 ± 136.5 m and in boys series was 642.3 ± 192.4 m (p = 0.017). The average height for boys was 1.50 ± 0.08 m and for girls was 1.53 ± 0.08 m (p = 0.245). The average BMI for boys was 18.3 ± 1.6 kg/m2 and for girls was 19.3 ± 2.2 kg/m2 (p = 0.041). Pearson's correlation coefficient between the average of meters walked for all the 60 children together and CRE was 0.570 (p < 0.001). Conclusions: Boys showed a greater WD than girls in ISWT. There was no influence of age, weight, height or BMI on distance walked on the ISWT A positive correlation is shown between the WD and the CRE.

Muscular Behavior during Inspiratory Training in Patients with a Complete Cervical Spinal Cord Injury: Pilot Study

Introduction: There is a huge variety of inspiratory muscle training protocols in patients with complete cervical spinal cord injury. None of them provide information about muscle behavior and its relationship with effort and fatigue sensation perceived by the subject.Objective: Analyze the relationship between the behavior of the Median Frequency (MF) and the Root Mean Square (RMS) of diaphragm (DPH) and sternocleidomastoid (ECOM) muscles and Subjective Fatigue Sensation (SFS) during an inspiratory muscle training session using a threshold valve in patients with CCSCI.Methods: Electromyographic activity of the DPH and ECOM during a fifteen minutes training session using a threshold valve with a Maximum Inspiratory Pressure (MIP) of 30% was recorded. Median Frequency average and the Root Mean Square of DPH and ECOM was calculated. SFS was recorded every minute. The correlation between variables was determined by Spearman rho.Results: The correlation between SFS and MF of the DPH was 0.22. The correlation between SFS and MF of the ECOM was 0.36. The correlation between SF and RMS_INDEX was -0.09.Conclusion: There is no correlation between the variables studied. The RMS_INDEX is presented as a useful tool to describe the muscle behavior during training with threshold valve.Results: The correlation between SFS and MF of the DPH was 0.22. The correlation between SFS and MF of the ECOM was 0.36. The correlation between SF and RMS_INDEX was -0.09.Results: The correlation between SFS and MF of the DPH was 0.22. The correlation between SFS and MF of the ECOM was 0.36. The correlation between SF and RMS_INDEX was -0.09.Comportamento muscular durante treino inspiratório em pacientes com lesão medular cervical completa: estudo pilotoIntrodução: Existe uma grande variedade de protocolos de treinos inspiratórios em pacientes com lesão medular cervical completa. Nenhum deles passa informação a respeito do comportamento muscular nem sua relação com a sensação de esforço e fadiga percebida pelo sujeito.Objetivo: Analisar a relação entre o comportamento da FM e raiz media quadrática (RMS) de diafragma (DPH) e esternocleidomastóideo (ECOM) e a SSF durante uma sessão de treino de musculatura inspiratória com válvula umbral em pacientes com LMCC.Métodos: Foi registrada a atividade eletromiográfica do diafragma e o esternocleidomastoideo durante quinze minutos de treino com válvula umbral a 30% de PIM. Foi calculada a frequência média e a raiz quadrada média do DPH e ECOM. Foi registrada a SSF a cada minuto. Foi determinada a correlação entre as variáveis mediante rho de Spearman.Resultados: A correlação entre SSF e FM de DPH foi 0.22. A correlação entre SSF e FM de ECOM foi 0.36. A correlação entre SSF e RMS_INDEX foi -0.09.Conclusão: Não existe correlação entre as variáveis estudadas. O RMS_INDEX é apresentado como uma ferramenta útil para descrever o comportamento muscular durante um treino com a válvula umbral.

A Comprehensive Literature Review of COPD-Related Fatigue

Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease and major cause of disability. COPD may be considered a systemic disease, which causes an array of symptoms, one of which is the subjective sensation of fatigue. In recent years, COPD-related fatigue (COPD-RF) has increasingly been recognised as an important area of research. The aim of this paper is to comprehensively review the literature concerning this topic and to summarise existing knowledge on the subjective perception of fatigue in people with COPD. This paper provides a narrative review of literature in this area. The search used the electronic databases of OVID MEDLINE and EMBASE included original studies from 1980 to December 2011. The databases were searched using the key MeSH terms COPD and Fatigue. In total 40 relevant publications were identified. This literature review covers the following areas identified by research studies: fatigue in COPD in comparison with healthy older people, gender differences, patients’ experience of fatigue, prevalence of fatigue reporting in COPD, pattern and frequency of fatigue in COPD, the impact of fatigue on an individual’s life, predictors of fatigue, coping and treatment strategies for the management of fatigue. Furthermore, this review identifies areas for further research and makes recommendations for clinical practice.

Medial Orbitofrontal Cortex Is Associated with Fatigue Sensation

Fatigue is an indispensable bioalarm to avoid exhaustive state caused by overwork or stresses. It is necessary to elucidate the neural mechanism of fatigue sensation for managing fatigue properly. We performed H2 15O positron emission tomography scans to indicate neural activations while subjects were performing 35-min fatigue-inducing task trials twice. During the positron emission tomography experiment, subjects performed advanced trail-making tests, touching the target circles in sequence located on the display of a touch-panel screen. In order to identify the brain regions associated with fatigue sensation, correlation analysis was performed using statistical parametric mapping method. The brain region exhibiting a positive correlation in activity with subjective sensation of fatigue, measured immediately after each positron emission tomography scan, was located in medial orbitofrontal cortex (Brodmann's area 10/11). Hence, the medial orbitofrontal cortex is a brain region associated with mental fatigue sensation. Our findings provide a new perspective on the neural basis of fatigue.

Antifatigue effects of coenzyme Q10 during physical fatigue

Objective This study examined the effects of coenzyme Q10 administration on physical fatigue. Methods In a double-blinded, placebo-controlled, three crossover design, 17 healthy volunteers were randomized to oral coenzyme Q10 (100 or 300 mg/d) or placebo administration for 8 d. As a fatigue-inducing physical task, subjects performed workload trials on a bicycle ergometer at fixed workloads twice for 2 h and then rested for 4 h. During the physical tasks, subjects performed non-workload trials with maximum velocity for 10 s at 30 min (30-min trial) after the start of physical tasks and 30 min before the end of the tasks (210-min trial). Results The change in maximum velocity from the 30- to the 210-min trial in the 300-mg coenzyme Q10–administered group was higher than that in the placebo group. In addition, subjective fatigue sensation measured on a visual analog scale in the 300-mg coenzyme Q10–administered group after the fatigue-inducing physical task and recovery period was alleviated when compared with that in the placebo group. Conclusion Oral administration of coenzyme Q10 improved subjective fatigue sensation and physical performance during fatigue-inducing workload trials and might prevent unfavorable conditions as a result of physical fatigue.

Fatigue and multiple sclerosis

Even if the definition and pathophysiology of fatigue in multiple sclerosis (MS) are still debated, and despite the scarcity of objective markers correlated with the subjective sensation of fatigue, a review of the literature shows the importance of its detection and management, and allows one to propose therapeutic strategies. Fatigue is not only the most frequently reported symptom in MS, but also a frequent source of activity and participation limitations, psychological distress, and impairment of quality of life. Its management, which must be initiated early, is based on a comprehensive evaluation of its characteristics and consequences (sometimes with the use of scales such as the Fatigue Severity Scale and the Modified Fatigue Impact Scale), and on the identification of many potential contributing factors (psychological disorders, sleep disturbances, pain, infections and other comorbidities, medications, and deconditioning). Rehabilitative interventions are essential to the treatment of fatigue. Beyond the traditional energy conservation strategies and cooling techniques, several randomized controlled studies have demonstrated the positive impact of aerobic exercise. Medications are partially beneficial, and with the exception of amantadine, their efficacy has not been confirmed by randomized double-blind trials.

Reduced responsiveness is an essential feature of chronic fatigue syndrome: A fMRI study

BackgroundAlthough the neural mechanism of chronic fatigue syndrome has been investigated by a number of researchers, it remains poorly understood.MethodsUsing functional magnetic resonance imaging, we studied brain responsiveness in 6 male chronic fatigue syndrome patients and in 7 age-matched male healthy volunteers. Responsiveness of auditory cortices to transient, short-lived, noise reduction was measured while subjects performed a fatigue-inducing continual visual search task.ResultsResponsiveness of the task-dependent brain regions was decreased after the fatigue-inducing task in the normal and chronic fatigue syndrome subjects and the decrement of the responsiveness was equivalent between the 2 groups. In contrast, during the fatigue-inducing period, although responsiveness of auditory cortices remained constant in the normal subjects, it was attenuated in the chronic fatigue syndrome patients. In addition, the rate of this attenuation was positively correlated with the subjective sensation of fatigue as measured using a fatigue visual analogue scale, immediately before the magnetic resonance imaging session.ConclusionChronic fatigue syndrome may be characterised by attenuation of the responsiveness to stimuli not directly related to the fatigue-inducing task.

Upper trapezius muscle mechanomyographic and electromyographic activity in humans during low force fatiguing and non-fatiguing contractions

The purposes of this study were firstly to compare and investigate localised fatigue in the upper trapezius muscle in various arm positions as assessed by mechanomyographic (MMG) and surface electromyographic (EMG) signals and secondly to study the effects of different normalisation methods on MMG and EMG signals during non-fatiguing and fatiguing low level isometric contractions. The MMG, EMG and rate of perceived exertion were recorded from 11 subjects in five arm positions (0 degrees abduction and 0 degrees flexion, 45 degrees and 90 degrees flexion, 45 degrees and 90 degrees abduction) with different bilateral arm loads during 3 s for non-fatiguing (0-0.5-1 kg hand-load) and 3 min for fatiguing contractions (1 kg hand-load). The root mean square (RMS), average rectified value (ARV), mean power frequency (MNF), and median power frequency (MDF) of the MMG and EMG signals were computed and normalised with respect to the initial values obtained in the current arm position or in the reference position (0 degrees abduction and 0 degrees flexion) corresponding to the normal postural activity of the trapezius muscle. For fatiguing contractions, differences in magnitude of the increase in the RMS or ARV and decrease in the MNF or MDF were observed for EMG and MMG. The MMG amplitude and spectral changes followed the subjective sensation of fatigue and were not correlated to their EMG counterparts, suggesting that they may reflect different phenomena. For non-fatiguing contractions, normalisation to the current arm position entailed the loss of dynamic amplitude changes suggesting that a single reference contraction in the middle part of the range of movement is enough for proper normalisation of EMG and MMG signals. For fatiguing contractions, normalisation of the EMG and MMG to some extent can lead to a misleading interpretation. Assessment of the upper trapezius muscle by means of MMG may be valuable in ergonomics.

Electromyographic analysis of fatigue in temporalis and masseter muscles during continuous chewing.

The aim of this study was to evaluate the electromyographic changes in the anterior temporalis and masseter muscles after fatigue induced by continuous chewing. Surface electrodes were placed bilaterally over the anterior temporalis and masseter muscles of 31 subjects with normal dentition. Recordings were taken every minute from the beginning of chewing to the exact moment the volunteer reported subjective sensation of fatigue in the jaw muscles. The length of endurance period (fatigue threshold) was measured to each subject, as well as the average amplitude and duration of activation phase and duration of relaxation phase through electromyographic recording of each muscle. The average endurance period was about 500 s. No significant change occurred on the average amplitude of activation phase meanwhile the duration of both the activation and relaxation phase diminished after fatigue.

Responses of muscle sympathetic nerve activity to static biceps brachii contraction in humans.

The aim of the present study was to determine whether static biceps brachii contraction by handcurling enhances the muscle sympathetic nerve activity (MSNA) in the resting muscle. In six healthy men (age: 19-23 years), we measured MSNA in the tibial nerve microneurographically, with heart rate, blood pressure, biceps electromyogram (EMG), and the intensity of local fatigue sensation in the working muscle. Subjects performed static biceps brachii contraction for 2 min (short exercise) at 30% of maximal voluntary contraction, and then they made fatiguing exercise to exhaustion (long exercise). During the short exercise, the heart rate and mean arterial blood pressure increased significantly (p < 0.05). In the last 30s of the short exercise, the MSNA burst rate and total MSNA increased significantly but integrated EMG did not increase. In long exercise, MSNA burst rate, total MSNA, mean arterial blood pressure, heart rate, EMG activity, and local fatigue sensation increased progressively with advancing exercising time. There was a significant correlation between integrated EMG and total MSNA (r = 0.64, n = 63, p < 0.001), and local fatigue sensation and total MSNA (r = 0.41, n = 63, p < 0.001) during the long exercise. Post-exercise recovery of the MSNA response to static handcurling was more prompt in short exercise than that in long exercise. We conclude that MSNA is enhanced during submaximal static handcurling, and the magnitude of enhancement correlates with EMG activity and subjective fatigue sensation in the biceps brachii, which might be attributed to the stimulation of metaboreceptors in the working muscle.