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Kanajmi, Humaira', Meizul Zuki, and Damres Uker. "AGE AND WORK EXPERIENCES TO FATIQUE FEELINGS AND WORK PRODUCTIVITY RELATIONSHIP OF PALM OIL FRUIT BUNCH HARVEST WORKERS." Jurnal Agroindustri 7, no. 1 (May 27, 2017): 44–55. http://dx.doi.org/10.31186/j.agroind.7.1.44-55.
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Purpose of this research was to analyze the correlation between the factor of age with fatigue of worker, the factor of working experience with fatigue of worker, the factor of age and working experience with fatigue of worker, and fatigue of workers with work productivity in palm oil harvesting. Data were collectedby using quisionere. The analytical method used in this research is the analysis of correlation and linear regression.From the results of this study concluded that there was a significant, quite strong (r = 0.469) and in the same direction (positive) correlation between the age worker factor with fatigue of palm oil harvester by linear regression equation ????1 = 2,571 + 0,077 X1, there was a significant, but low (r = -0.344) and not in the same direction (negative) correlation between the factor of working experience with fatigue of palm oil harvester by linear regression equation ????1 = 6,303 - 0,067 X2, there was a significant and very strong correlation (R = 0.922) between factors of age and working experience with fatigue of palm oil harvester by linear regression equation ????1 = 0,742 + 0,178 X1 - 0,195 X2, and there was a significant, but low (r = -0.271) and not in the same direction (negative) correlation between the fatigue of workers with productivity of palm oil harvesting by linear regression equation ????2 = 258,45- 6,979 X. Labor of palm oil harvesting should be managed by factor age of workers and work experience in order to minimize fatigue of workers so that can improve productivity.
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Fudenberg, H. H., G. Pizza, C. DeVince, D. Ablashi, and D. Viza. "Antigen-specific transfer factor in chronic fatique immune dysregulation syndrome and viral infections." Clinical Immunology Newsletter 17, no. 6 (June 1997): 91–92. http://dx.doi.org/10.1016/s0197-1859(97)80303-2.
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Ada, Elif Nilay, Nikos Comoutos, S. İlke Bal, and Zekai Pehlivan. "BEDEN EĞİTİMİ DERSİNE YÖNELİK DURUMSAL GÜDÜLENME, TUTUM VE İÇSEL KONUŞMA ARASINDAKİ İLİŞKİ." e-Journal of New World Sciences Academy 15, no. 4 (October 31, 2020): 53–66. http://dx.doi.org/10.12739/nwsa.2020.15.4.2b0127.
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In this study was to determination of the relationship between situational motivation (SIM), self-talk (ST) and attitude towards physical education (PE) lesson and students' other perceptions (liking level of PE-SEV, the level of importance given to the PE by the student-KVO and the level of perception of the importance given to PE by the family-AVO). Furthermore, it has been done the comparisons in terms of age and gender. A total of 698 secondary school students aged between 11-14 in the study. In the findings, girls obtained higher means for all sub scales of SIM and attitude, while boys obtained higher score for worry dimension only of ST. Girls obtained higher scores for SEV and KVO, whereas boys obtained higher means for AVO. When the age increased, SEV, KVO, AVO, instrinsic motivation-IM, identification regulation-IR and attitude decreased but somatic fatique factor of negative ST increased. SEV, KVO and AVO were positive correlated with the positive dimesions whereas negative correlated with the negative dimensions. IM and IR dimensions were found positive correlated with positive ST dimensions and attitude; but extrinsic motivation and amotivation dimensions were found negative correlated with attitude and, positive correlated with negative ST dimensions.
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Duan, Zhihao, Jinliang Xu, Han Ru, and Menghui Li. "Classification of Driving Fatigue in High-Altitude Areas." Sustainability 11, no. 3 (February 4, 2019): 817. http://dx.doi.org/10.3390/su11030817.
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Driving fatigue is one of the main causes of traffic accidents. Thus, to prevent traffic accidents and ensure traffic safety, the properties of driving fatigue at the wheel must be determined. The Qinghai–Tibet Plateau in China is known for its high elevation, causing hypoxia, and presence of severely cold areas; all these easily lead to fatigue during driving. This, in turn, seriously affects the traffic safety on the high-altitude highway. Therefore, the factors leading to driving fatigue and the influence of high-altitude on driving fatigue affecting the driver must be further studied. In this study, we classified and quantified driving fatigue according to the driving fatigue degree. We determined three levels of driving fatigues (i.e., mild, moderate, and severe fatigues) to present their influence on drivers. Our study shows that in this high-altitude area, drivers became fatigued within a significantly shorter time.
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Gao, Yixiang, Maria Dietrich, and Guilherme N. DeSouza. "Classification of Vocal Fatigue Using sEMG: Data Imbalance, Normalization, and the Role of Vocal Fatigue Index Scores." Applied Sciences 11, no. 10 (May 11, 2021): 4335. http://dx.doi.org/10.3390/app11104335.
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Our previous studies demonstrated that it is possible to perform the classification of both simulated pressed and actual vocally fatigued voice productions versus vocally healthy productions through the pattern recognition of sEMG signals obtained from subjects’ anterior neck. In these studies, the commonly accepted Vocal Fatigue Index factor 1 (VFI-1) was used for the ground-truth labeling of normal versus vocally fatigued voice productions. Through recent experiments, other factors with potential effects on classification were also studied, such as sEMG signal normalization, and data imbalance—i.e., the large difference between the number of vocally healthy subjects and of those with vocal fatigue. Therefore, in this paper, we present a much improved classification method derived from an extensive study of the effects of such extrinsic factors on the classification of vocal fatigue. The study was performed on a large number of sEMG signals from 88 vocally healthy and fatigued subjects including student teachers and teachers and it led to important conclusions on how to optimize a machine learning approach for the early detection of vocal fatigue.
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Pan, Long, Jian Chao Pang, Yu Jun Xie, Meng Xiao Zhang, Liang Liang Nie, Yun Xian Mao, and Zhe Feng Zhang. "A fatigue life prediction method from magnetic pole material to simulation part." International Journal of Damage Mechanics 28, no. 9 (March 13, 2019): 1438–54. http://dx.doi.org/10.1177/1056789519835904.
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Due to the higher reliability needs of the large moving component motor-generator rotor, the assessment of the service life has drawn more and more attention. After finite element analysis of the rotor, the simulation part which can represent the magnetic pole with the most dangerous position of the rotor was designed to investigate the S–N curves. Compared with the conventional specimen, considering the main influencing factors of fatigue life for simulation part, the comprehensive factor was proposed to establish the fatigue life relationship between magnetic pole material and simulation part. It was found that the calculation method of fatigue notch factor based on the notch sensitivity factor is relatively simple and practical, and there is no significant effect of surface roughness on high and low cycle fatigues for low roughness ( R a is about 1 µm), and the dimension factor changes linearly with the scale factor. Based on those results, a fatigue life prediction method was proposed and validated, and the predicted results were in good agreement with the experimental data. This study will provide a reasonable reference to determine the fatigue life prediction of large moving components.
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Corwin, Elizabeth J., Laura Cousino Klein, and Kristin Rickelman. "Predictors of Fatigue in Healthy Young Adults: Moderating Effects of Cigarette Smoking and Gender." Biological Research For Nursing 3, no. 4 (April 2002): 222–33. http://dx.doi.org/10.1177/109980040200300407.
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Fatigue is a common complaint of patients seen in primary care. Factors that contribute to fatigue in a patient population include poor health status, psychological stress, poor nutrition, and pregnancy. Less well understood are factors that contribute to fatigue among healthy, nonpregnant individuals. Within the framework of the theory of unpleasant symptoms, 40 healthy young smoking and nonsmoking adults between the ages of 18 and 35 were evaluated to determine self-report level of fatigue and contributing physiological, psychological, and situational factors. Results indicate that while self-report of fatigue did not vary in this population based on gender, subjects who were moderate to heavy cigarette smokers were significantly more fatigued than were nonsmokers (F= 10.24, df = 1, 38, P < 0.01), with the effect being specific to male smokers. Self-report of fatigue did not correlate with body mass index, baseline inflammatory or immune status, or blood pressure. Positive psychological and situational predictors of fatigue included depression (r = 0.556, P < 0.001), state anxiety (r = 0.569, P < 0.001), sleep quality (r = –0.399, P < 0.05), and sleep quantity (r = –0.411, P < 0.05). These results suggest that psychological and situational factors are key contributors to fatigue in young adults and that smoking is a risk factor for fatigue in men.
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Perry, Edward Belk, Sudhanshu Bharat Mulay, Jayesh Kamath, Robert J. Dowsett, Jacob Neuwirth, James Grady, Courtney Gold, Bruce Liang, and Susan Tannenbaum. "Factors influencing fatigue in breast cancer patients undergoing breast irradiation." Journal of Clinical Oncology 33, no. 28_suppl (October 1, 2015): 96. http://dx.doi.org/10.1200/jco.2015.33.28_suppl.96.
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96 Background: We are conducting an exploratory, prospective study to investigate factors associated with radiation-induced fatigue in women with early breast cancer undergoing radiation therapy (RT) for breast conservation. Our hypothesis is that fatigue associated with adjuvant RT is related to tissue damage by apoptosis and inflammation, and to baseline psychological profiles. Methods: All subjects were assessed immediately before RT (T1), mid-point of RT (T2), end of RT (T3), 6 months (T4) and 1 year (T5) after completing RT. Clinical evaluations of skin toxicity, laboratory measures, fatigue, distress, depression, anxiety, sleep, energy and pain were assessed using validated measures. Results: Thirty-one subjects (target 50) have been enrolled to date; 23 have completed T3 and are presented here. 35% had a history of depression and 17% are currently depressed; 22% had past and current anxiety. BCTOS breast pain, tenderness and sensitivity increased during RT and were consistent with functional pain scores. No clinically relevant changes in energy or distress were seen. Despite a notable prevalence of depression and anxiety at baseline, there were no relevant changes in depression or anxiety. Most IL-1β, IL-4, IL-6 and IL-10 levels were undetectable. 39% of subjects showed increases in fatigue and were 14 years younger than non-fatigued subjects. Fatigued subjects had more frequent past (44%) and current (33%) depression than non-fatigued subjects (29% and 7%, respectively), and woke up tired more frequently (44% versus 0%). Current depression, but not fatigue, was associated with decreased a.m. cortisol levels during RT. 56% of fatigued subjects had an RTOG Acute Skin Toxicity score > 1 and 78% had BCTOS breast-specific pain subscales scores ≥ 3 during RT vs. 21% and 14% of non-fatigued subjects, respectively. Serum caspase-1 (inflammation) and caspase-3 (apoptosis), hs-CRP and TNF-α were increased but not associated with fatigue. Conclusions: Our preliminary findings suggest that radiation-associated fatigue is complex and, as hypothesized, is dependent on a patient’s psychological profile in the setting of skin toxicity and insomnia. If this data holds at study completion, it may guide clinical interventions.
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Asprusten, Tarjei Tørre, Maria Pedersen, Eva Skovlund, and Vegard Bruun Wyller. "EBV-requisitioning physicians’ guess on fatigue state 6 months after acute EBV infection." BMJ Paediatrics Open 3, no. 1 (February 2019): e000390. http://dx.doi.org/10.1136/bmjpo-2018-000390.
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We assessed referring medical practitioner’s ability to predict chronic fatigue development in adolescents presenting with acute infectious mononucleosis. Compared with ‘not fatigued’ being predicted as ‘unsurely fatigued’ and ‘likely fatigued’ were both strongly associated with developing fatigue 6 months later (OR 2.5, 95% CI 1.16% to 5.47% and 3.2, 95% CI 1.19% to 8.61%, respectively, P=0.012). The positive and negative predictive values were 66% and 62%, respectively. Disentangling the physician’s intuition may be of interest in further investigations of risk factors and prophylactic factors for fatigue development.
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Nap-van der Vlist, Merel M., Geertje W. Dalmeijer, Martha A. Grootenhuis, Kors van der Ent, Marry M. van den Heuvel-Eibrink, Joost F. Swart, Elise M. van de Putte, and Sanne L. Nijhof. "Fatigue among children with a chronic disease: a cross-sectional study." BMJ Paediatrics Open 5, no. 1 (February 2021): e000958. http://dx.doi.org/10.1136/bmjpo-2020-000958.
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ObjectiveTo determine: (1) which biological/lifestyle, psychological and/or social factors are associated with fatigue among children with a chronic disease and (2) how much each of these factors contributes to explaining variance in fatigue.Design and settingThis was a cross-sectional study across two children’s hospitals.PatientsWe included children aged 8–18 years who visited the outpatient clinic with cystic fibrosis, an autoimmune disease or postcancer treatment.Main outcome measuresFatigue was assessed using the PedsQL Multidimensional Fatigue Scale. Generic biological/lifestyle, psychological and social factors were assessed using clinical assessment tools and questionnaires. Multiple linear regression analyses were used to test the associations between these factors and fatigue. Finally, a multivariable regression model was used to determine which factor(s) have the strongest effect on fatigue.ResultsA total of 434 out of 902 children were included (48% participation rate), with a median age of 14.5 years; 42% were male. Among these 434 children, 21.8% were severely fatigued. Together, all biopsychosocial factors explained 74.6% of the variance in fatigue. More fatigue was uniquely associated with poorer physical functioning, more depressive symptoms, more pressure at school, poorer social functioning and older age.ConclusionsFatigue among children with a chronic disease is multidimensional. Multiple generic biological/lifestyle, psychological and social factors were strongly associated with fatigue, explaining 58.4%; 65.8% and 50.0% of the variance in fatigue, respectively. Altogether, almost three-quarters of the variance in fatigue was explained by this biopsychosocial model. Thus, when assessing and treating fatigue, a transdiagnostic approach is preferred, taking into account biological, psychological and social factors.
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Sakane, Masao, Masateru Ohnami, Teruyoshi Awaya, and Nakao Shirafuji. "Frequency and Hold-Time Effects on Low Cycle Fatigue Life of Notched Specimens at Elevated Temperature." Journal of Engineering Materials and Technology 111, no. 1 (January 1, 1989): 54–60. http://dx.doi.org/10.1115/1.3226433.
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This paper describes the frequency and hold-time effects on high temperature low cycle fatigue for round notched specimens. Unnotched and notched specimens having different elastic stress concentration factors were fatigued under triangular and trapezoidal stress waves at frequencies ranging from 5 Hz to 0.0001 Hz at 873 K. The three specific fracture characteristics were observed: cycle dependent, time dependent, and cycle-time dependent. The respective notch sensitivity occurred in the respective fracture regime. The fatigue life of notched specimens was predicted from the elastic-plastic-creep cyclic FEM analysis using the linear damage rule and the strain range partitioning rule. Both the life prediction methods predicted the creep-fatigue life within almost a factor of two scatter band.
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Torres, Mylin Ann, Thaddeus Pace, Jennifer Felger, Tian Liu, Karen D. Godette, Liza Jane Stapleford, Donna Mister, and Andrew H. Miller. "A prospective longitudinal study of cancer-related fatigue in patients undergoing breast-conserving surgery and radiation with or without chemotherapy for breast cancer." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): 9122. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.9122.
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9122 Background: We prospectively evaluated risk factors for persistent cancer-related fatigue in women with breast cancer undergoing lumpectomy with or without chemotherapy (CTX) prior to whole breast radiotherapy (XRT). We assessed the potential role of inflammatory mediators, demographic characteristics, and treatment history including CTX. Methods: Following lumpectomy, 60 women received a definitive course of whole breast XRT (50 Gy plus a 10 Gy boost). Prior to XRT, at week 6 of XRT, and 6 weeks post XRT, subjects completed the Multidimensional Fatigue Inventory (MFI) and underwent blood draws for inflammatory mediators (protein and mRNA). Results: Independent multivariate analyses of clinical and demographic factors revealed that CTX (p<.001) , given neoadjuvantly or adjuvantly, and age <50 (p=.03) were significant predictors of higher fatigue scores post XRT. Mean MFI scores in patients treated with CTX (n=24) were 20 points higher than patients not treated with CTX (p<.001) with a clinically meaningful difference in scores being 10 points on the MFI. Gene ontology analysis of differentially expressed genes indicated increased activation of genes involved in immune and inflammatory responses in fatigued vs. non-fatigued patients (p<.001). Of the inflammatory mediators, plasma IL-6 prior to XRT was the strongest predictor of post XRT fatigue (p=.02). Moreover, plasma IL-6 concentrations prior to XRT were significantly higher in patients who received CTX (mean 4.96 vs. 2.53, p=.01). Patients who received CTX also had significantly higher levels of NF Kappa B DNA binding 6 weeks post XRT (p<.001), and transcription factor binding analysis revealed a greater representation of genes with the NF Kappa B DNA binding motif in fatigued vs. non-fatigued patients (p =.05). Conclusions: Collectively, these data suggest an interaction between CTX and XRT leading to inflammation and fatigue several weeks post XRT. This relationship was independent of whether CTX was given pre or post-operatively. Treatments targeting inflammation before XRT may reduce fatigue post therapy, particularly in patients previously treated with CTX.
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Hermawan, Bambang, Soebijanto Soebijanto, and Widodo Haryono. "Sikap dan beban kerja, dan kelelahan kerja pada pekerja pabrik produksi aluminium di Yogyakarta." Berita Kedokteran Masyarakat 33, no. 4 (April 1, 2017): 213. http://dx.doi.org/10.22146/bkm.16865.
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Attitude, workload and fatigue among aluminum production factory workers in YogyakartaPurpose This study aimed to determine the effect of age, occupation, nutritional status, sleep duration, smoking habit of work attitude and work load to work fatigue on factory workers of "SP" alumunium unit of Yogyakarta.MethodsThis research was an observational analytic study using a cross-sectional design. The population was 153 people. The sample was taken based on the total sampling on the production unit of the Alumunium "SP" factory. Data were analyzed by using univariate, bivariate, and multivariate analyses.ResultsThis study found age to increase risk factors for work fatigue (OR = 2.52). The period of work is another risk factor that affects work fatigue (OR=2.36). Work attitudes and workload are also risk factors for work fatigue (OR=2.4 and OR=3.18). Meanwhile, nutritional status, sleep duration and smoking are not risk factors for work fatigue. Multivariate analysis showed that the most influencing variable of work fatigue was work attitude (p-value=0.022) with risk level 3 times greater in work attitude of weight category and age p-value=0.019 with risk level 3 times greater in people aged > 35 years.ConclusionWe found that work attitudes, workload, age, length of service, sleep duration can affect work fatigue while nutritional status and smoking habits had no effect on work fatigue.
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van der Linden, Dimitri, Michael Frese, and Sabine Sonnentag. "The Impact of Mental Fatigue on Exploration in a Complex Computer Task: Rigidity and Loss of Systematic Strategies." Human Factors: The Journal of the Human Factors and Ergonomics Society 45, no. 3 (September 2003): 483–94. http://dx.doi.org/10.1518/hfes.45.3.483.27256.
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We investigated the impact of mental fatigue on exploration in a complex computer task. The exploration behavior of participants who underwent a fatigue manipulation (N = 36) was compared with that of a control (nonfatigued) group (N = 32). A distinction was also made between participants with high or low levels of general computer experience. Results showed that fatigued participants used significantly less systematic exploration and made more errors than did nonfatigued participants. Fatigued participants with low computer experience also showed significantly more rigid behavior than did the other participants. No differences were found on the number of subtasks solved. Compared with low-experience participants, highly experienced participants showed significantly more systematic exploration, less unsystematic trial and error, solved more subtasks, and made fewer errors (marginally significant p = .056). Findings were interpreted as the result of reduced task engagement under fatigue and reduced involvement of executive control on behavior. Actual or potential applications of this research include guidelines to prevent detrimental effects of mental fatigue on exploration behavior.
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Perttula, Pia, Tarja Ojala, and Eeva Kuosma. "Factors in the Fatigue of Heavy Vehicle Drivers." Psychological Reports 108, no. 2 (April 2011): 507–14. http://dx.doi.org/10.2466/06.13.22.pr0.108.2.507-514.
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This study assessed work-related and driver-related factors in fatigue among Finnish heavy vehicle drivers. 683 professional drivers responded to a questionnaire, 27.8% of whom reported often feeling fatigue during their work shifts. Of the respondents, 27.5% reported having momentarily fallen asleep at the wheel while driving during the past year. Almost half (46.8%) of the fatigued drivers estimated the reasons for momentarily falling asleep were work-related. Long working shifts and short sleeps significantly increased the risk of momentarily falling asleep at the wheel. The risk of fatigue was the highest for the drivers who were unable to choose the time of their breaks.
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Herlambang, Mega B., Niels A. Taatgen, and Fokie Cnossen. "The Role of Motivation as a Factor in Mental Fatigue." Human Factors: The Journal of the Human Factors and Ergonomics Society 61, no. 7 (February 28, 2019): 1171–85. http://dx.doi.org/10.1177/0018720819828569.
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Objective: The aim of this study was to assess motivation as a factor in mental fatigue using subjective, performance, and physiological measures. Background: Sustained performance on a mentally demanding task can decrease over time. This decrement has two possible causes: a decline in available resources, meaning that performance cannot be sustained, and decrement in motivation, meaning a decline in willingness to sustain performance. However, so far, few experimental paradigms have effectively and continuously manipulated motivation, which is essential to understand its effect on mental fatigue. Method: Twenty participants performed a working memory task with 14 blocks, which alternated between reward and nonreward for 2.5 hr. In the reward blocks, monetary rewards could be gained for good performance. Besides reaction time and accuracy, we used physiological measures (heart rate variability, pupil diameter, eyeblink, eye movements with a video distractor) and subjective measures of fatigue and mental effort. Results: Participants reported becoming fatigued over time and invested more mental effort in the reward blocks. Even though they reported fatigue, their accuracy in the reward blocks remained constant but declined in the nonreward blocks. Furthermore, in the nonreward blocks, participants became more distractable, invested less cognitive effort, blinked more often, and made fewer saccades. These results showed an effect of motivation on mental fatigue. Conclusion: The evidence suggests that motivation is an important factor in explaining the effects of mental fatigue.
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Pokhyl, Y. A., L. F. Yakovenko, E. N. Aleksenko, and V. A. Lototskaya. "Proposals for the ISS: «Penta-Fatigue» - Experiment Influence of space factors on fatigue fractureresistance of structural materials." Kosmìčna nauka ì tehnologìâ 6, no. 4 (July 30, 2000): 45. http://dx.doi.org/10.15407/knit2000.04.045.
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Shao, Hai-peng, Juan Yin, Wen-hao Yu, and Qiu-ling Wang. "Aberrant Driving Behaviours on Risk Involvement among Drivers in China." Journal of Advanced Transportation 2020 (June 29, 2020): 1–8. http://dx.doi.org/10.1155/2020/8878711.
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The purpose of this study is to validate the version of Driver Behaviour Questionnaire (DBQ) by considering distractions, fatigue, and drunk driving, the main reasons for accidents in China, as independent parts of violations and errors and further explore the effects of demographic/driving variables and all factors on risk involvement (accident involvement and penalized points). 241 drivers filled in a self-completion questionnaire with 28 items conducted in Xi’an in August 2018. Exploratory factor analysis confirmed a five-factor structure, including violations, distracted driving, errors, drunk driving, and fatigued driving. The frequency of aberrant driving behaviours indicated that distractions were the most prevalent behaviours followed by fatigue. The results showed that drivers with lower education and longer annual mileages were positive with accident involvement while there was no significance in penalized points. Violations and distractions were important factors causing both accidents and penalized points. Therefore, it is effective to reduce accident involvement by establishing educational training and related laws or installing intelligent monitor vehicle equipment to warn drivers to improve safety.
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Ahmed, Debra S., and Suzanne Fecik. "The Fatigue Factor." American Journal of Nursing 99, no. 9 (September 1999): 12. http://dx.doi.org/10.1097/00000446-199909000-00007.
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Huynh, Do Song Toan, Hieu Giang Le, Thi Ngoc Huyen Nguyen, and Son Minh Pham. "Enhancing the Fatigue Property of Nylon 6 by Using Glass-Fiber Reinforcement and Injection Molding." Materials Science Forum 971 (September 2019): 85–90. http://dx.doi.org/10.4028/www.scientific.net/msf.971.85.
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In this study, Nylon 6 (PA6) was reinforced with glass fibers and molded using different injection parameters. The PA6 samples were then subjected to fatigue tests, and the results were processed to study (i) how the glass fibers affected the PA6 fatigue displacement and (ii) which injection parameters influenced the PA6 fatigue property. To do so, single-factor experimental designs were implemented in which the control factors were the glass-fiber percentage, the melt temperature, the hold pressure, the hold time, the injection pressure, and the injection time. Correlational analyses were used to predict the relationships between the control factors and fatigue results. A two-factor design was then applied to determine the two factors that influenced the PA6 fatigue displacement the most, with analysis of variance being used to determine how the factors affected the fatigue property. In this study of injection plastic, the glass-fiber percentage of PA6 composite was found to be the main factor that affected the fatigue displacement the most.
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Dominguese, David J., Jeff Seegmiller, and B. Andrew Krause. "Alterations in Peak Ground-Reaction Force During 60-cm Drop Landings Caused by a Single Session of Repeated Wingate Anaerobic Tests." Journal of Sport Rehabilitation 21, no. 4 (November 2012): 306–12. http://dx.doi.org/10.1123/jsr.21.4.306.
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Context:Lower extremity injury is prevalent among individuals participating in sports. Numerous variables have been reported as predisposing risk factors to injury; however, the effects of muscle fatigue on landing kinetics are unclear.Objectives:To investigate the effects of a single session of repeated muscle fatigue on peak vertical ground-reaction force (GRF) during drop landings.Design:Mixed factorial with repeated measures.Setting:Controlled laboratory.Participants:10 female and 10 male healthy recreational athletes.Intervention:Subjects performed 3 fatigued drop landings (60 cm) after four 20-s Wingate anaerobic tests (WATs) with 5 min of active recovery between fatigued conditions.Main Outcome Measures:Kinetic data of peak forefoot (F1) force, peak rear-foot (F2) force, and anteroposterior (AP) and mediolateral (ML) forces at both F1 and F2.Results:A significant main effect was observed in the nonfatigued and fatigued drop landings in respect to peak F2 force. The greatest significant difference was shown between the first fatigued drop-landing condition and the last fatigued drop-landing condition. No significant difference was observed between genders for all GRF variables across fatigue conditions.Conclusion:A single session of repeated conditions of anaerobic muscle fatigue induced by WATs caused an initial reduction in peak F2 force followed by an increase in peak F2 force across conditions. Muscle fatigue consequently alters landing kinetics, potentially increasing the risk of injury.
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Zeng, Rong Chang, En Hou Han, and Wei Ke. "Fatigue and Corrosion Fatigue of Magnesium Alloys." Materials Science Forum 488-489 (July 2005): 721–24. http://dx.doi.org/10.4028/www.scientific.net/msf.488-489.721.
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This paper consists of a review of investigations and the factors affecting the fatigue of Mg and its alloys. The effect of materials, loading conditions and environmental factors on fatigue is discussed in detail. Particular attention has been paid to the influence of frequencies and the pH value of solutions on the fatigue life. The correlation between the threshold stress intensity factor range (ΔKth) and load ratio (R) for Mg alloy fatigue crack propagation (FCP) is summarized in a figure. Finally, the mechanisms of fatigue and corrosion fatigue (CF), crack initiation and crack propagation are also discussed.
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Radzak, Kara N., and Christopher D. Stickley. "Fatigue-Induced Hip-Abductor Weakness and Changes in Biomechanical Risk Factors for Running-Related Injuries." Journal of Athletic Training 55, no. 12 (September 18, 2020): 1270–76. http://dx.doi.org/10.4085/1062-6050-531-19.
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Context Despite overlap between hip-abductor (HABD) weakness and fatigue-induced changes in running, the interaction of these theorized contributors to running injuries has been underevaluated. Objective To assess the effects of a fatiguing run on HABD torque and evaluate the correlation between HABD torque and previously identified running-related injury pathomechanics while participants were rested or fatigued. Design Crossover study. Setting Laboratory. Patients or Other Participants A total of 38 healthy, physically active males (age = 21.61 ± 4.02 years, height = 1.78 ± 0.08 m, body mass = 76.00 ± 12.39 kg). Intervention(s) Data collection consisted of rested-state collection, a fatiguing treadmill-run protocol, and fatigued-state collection. For the HABD measures, side-lying handheld-dynamometer isometric tests were performed and converted to torque using femur length. For the gait analysis, kinematic (240 Hz) and kinetic (960 Hz) running (4.0 m/s) data were collected for 3 trials. The fatigue protocol involved a graded exercise test and 80% o2max run to exhaustion. Immediately after the run, fatigued-state measures were obtained. Main Outcome Measure(s) Variables of interest were HABD torque and peak angles, velocities, and moments for hip and knee adduction and internal rotation. Differences between conditions were compared using paired t tests. Pearson correlation coefficients were calculated to evaluate relationships between HABD torque and biomechanical variables. Results Fatigue decreased HABD torque and increased hip-adduction angle, knee-adduction velocity, and hip and knee internal-rotation velocities and moments (all P values < .05). In the rested state, HABD torque was correlated with hip-adduction velocity (r = –0.322, P = .049). In the fatigued state, HABD torque was correlated with hip-adduction velocity (r = –0.393, P = .015), hip internal-rotation velocity (r = –0.410, P = .01), and knee-adduction angle (r = 0.385, P = .017) and velocity (r = −0.378, P = .019). Conclusions Changes in joint velocities due to fatigue and correlations between HABD torque and hip- and knee-joint velocities highlight the need to consider not only the quantity of HABD strength but also the rate of eccentric control of HABDs.
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Li, You Tang, Ping Ma, and Ming Song. "Effect of Supporting Conditions on the Fatigue Life of Shaft Based on Product Lifecycle Management." Key Engineering Materials 385-387 (July 2008): 109–12. http://dx.doi.org/10.4028/www.scientific.net/kem.385-387.109.
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An anti-fatigued criterion of annularly breached shaft on mechanical design has been put forward, and the main factors that affect fatigue life of shaft are discussed. The interrelation of the main factors and the framework is founded. A new assessment method to fatigue life of shaft has been put forward according to Corten-Dolan’s theory modified Miner's rule. The effect of supporting conditions to fatigue life of shaft is discussed and the influencing parameters are obtained. The results show that the fatigue life of broad support in two sides is longer than that of narrow support in two sides. The results will establish the base of anti-fatigue design of shaft.
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Bedaiwi, Mohamed, Ismail Sari, Arane Thavaneswaran, Renise Ayearst, Nigil Haroon, and Robert D. Inman. "Fatigue in Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis: Analysis from a Longitudinal Observation Cohort." Journal of Rheumatology 42, no. 12 (November 1, 2015): 2354–60. http://dx.doi.org/10.3899/jrheum.150463.
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Objective.In this study, we aimed to address the prevalence of fatigue, its associated factors, and the effect of tumor necrosis factor inhibitors (TNFi) on this subgroup of patients in a large axial spondyloarthritis (axSpA) cohort.Methods.The study included 681 patients [ankylosing spondylitis (AS) and nonradiographic axSpA (nr-axSpA)]. The Fatigue Severity Scale (FSS) and the Bath AS Disease Activity Index question 1 (BASDAI Q1) indices were used for fatigue assessment. Severe fatigue was defined as an FSS ≥ 4 or a BASDAI Q1 ≥ 5. Disease activity, function, and quality of life (QoL) measures were recorded. Patients who had been treated with TNFi were identified, and baseline and followup data were analyzed.Results.Of the cohort, 67.3% had severe fatigue, and the prevalence was similar between AS (67.2%) and nr-axSpA (68.2%). Severely fatigued patients tended to have higher disease activity scores, increased acute-phase proteins, and decreased QoL measures. TNFi therapy was associated with improvement in disease activity, and although this treatment led to significantly decreased fatigue scores, this reduction was not optimal in the majority of patients with 80% continuing to have severe fatigue according to their posttreatment scores. Health Assessment Questionnaire, mean scores of BASDAI Q5 and Q6, and BASDAI enthesitis were independent predictors of fatigue severity.Conclusion.Fatigue is a common symptom in axSpA, and the burden of fatigue among patients with nr-axSpA is similar to that seen in AS. While biologics are effective in improving disease activity, their effect on fatigue is more limited. In axSpA, fatigue remains unresponsive to TNFi in nearly 80% of patients.
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Kumamoto, Tsuneo, Toshiaki Seko, Ryo Matsuda, and Sayo Miura. "Repeated standing back extension exercise: Influence on muscle shear modulus change after lumbodorsal muscle fatigue." Work 68, no. 4 (April 27, 2021): 1229–37. http://dx.doi.org/10.3233/wor-213452.
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BACKGROUND: In low back pain, multifidus muscle fibers reportedly exhibit increased stiffness. Low back pain was associated with lumbodorsal muscle fatigue. There is no report of using shear modulus to verify the mechanism of an immediate effect of exercise on low back pain. Here, temporary lumbodorsal muscle fatigue was created, simulating fatigue-related nonspecific low back pain. OBJECTIVE: To assess the effect of standing back extension exercise on fatigued lumbodorsal muscle based on the results of multifidus muscle elasticity measured using shear wave elastography. METHODS: Thirty-three healthy subjects were randomly divided into three groups. The subjects performed the Biering-Sorensen test as the fatigue-task of the lumbodorsal muscle before the standing back extension exercise. The fatigue-exercise group exercised five sets after completing the fatigue-task. The fatigue-non-exercise group remained standing for the same duration as the fatigue-exercise group without doing the exercise after the fatigue-task. The non-fatigue-exercise group exercised five sets of without performing the fatigue-task. As intra-group and inter-group factors, the shear modulus of the multifidus muscle was compared before and after the exercise. RESULTS: The shear modulus of the multifidus muscle after the standing back extension exercise was significantly lower in the fatigue-exercise group, and no significant decrease was observed in the fatigue-non-exercise and non-fatigue-exercise group. CONCLUSIONS: The standing back extension exercise improved the shear modulus of the fatigued multifidus muscle. Therefore, it was suggested that the change in the elasticity of fatigued muscle might lead to the prevention of low back pain caused by muscle fatigue.
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Sabery, Mahdieh, Mansoureh Zagheri Tafreshi, Meimanat Hosseini, Jamileh Mohtashami, and Abbas Ebadi. "Development and Psychometric Assessment of Risk Factors of Compassion Fatigue Inventory in Nurses." Journal of Nursing Measurement 27, no. 2 (August 1, 2019): E62—E80. http://dx.doi.org/10.1891/1061-3749.27.2.e62.
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Background and PurposeIdentifying the risk factors of compassion fatigue is the basic step in designing effective interventions to prevent and manage compassion fatigue. This study developed an inventory of compassion fatigue risk factors and investigated its psychometric properties.MethodsThis methodological study consisted of two phases: item pool generation through semistructured interviews with 13 nurses and reviewing of 38 related articles and the psychometric validation.ResultsThe initial item pool contained 62 items. The psychometric properties was examined and exploratory factor analysis revealed a four-factor structure. Risk Factors of Compassion Fatigue Inventory (RFCFI) contained 20 items. The Cronbach's alpha, intra-class correlation coefficient (ICC), and standard error of measurement (SEM) were .86, 0.83, and 5.73 respectively.ConclusionRFCFI is a short, self-reporting, valid, and reliable inventory for determining the risk factors of compassion fatigue in nurses and can be easily used by managers, nurses, and scholars.
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Schjolberg, Tore Kr, Marylin Dodd, Nils Henriksen, and Tone Rustoen. "Factors affecting hope in a sample of fatigued breast cancer outpatients." Palliative and Supportive Care 9, no. 1 (February 25, 2011): 63–72. http://dx.doi.org/10.1017/s1478951510000556.
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AbstractObjective:The aims of this study of women with breast cancer were: to describe the levels of hope and compare hope scores for these patients with a sample from the general Norwegian population; to describe the relationship between hope and fatigue; and finally to evaluate the effect of demographic and clinical characteristics and fatigue on hope.Method:A total of 160 Norwegian outpatients with cancer and fatigue (>2.5 on a 0–10 scale) completed the Herth Hope Index (HHI), Fatigue Questionnaire (FQ), and Self-administered Comorbidity Questionnaire (SCQ).Results:The mean age of the women was 55.3 years (SD = 9.4), 81% lived with someone, and 67% were employed. The most common comorbidities were back pain (42%), osteoarthritis (26%), and headache (19%). The fatigued breast cancer patients reported significantly higher total hope scores than the general Norwegian population (p < .0001). The difference was largest in the individual item “I can see a light in the tunnel,” to which the cancer sample reported the highest scores, but they also felt more “scared about the future.” Total hope score was negatively correlated with total fatigue (TF), mental fatigue (MF), and chronic fatigue (CF), but not with physical fatigue (PF). Demographic and clinical characteristics were not significantly related to hope, except that patients who were married or living with someone showed significantly higher total hope scores.Significance of results:The higher levels of hope in breast cancer patients compared with the general Norwegian population may reflect a response shift in patients after getting a cancer diagnosis. The fact that a significant relationship was found between total hope scores and living arrangements may indicate that hope is easier to establish when patients have someone to relate to or receive support from. Hope and total fatigue were significantly, but weakly correlated.
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Liu, Yong Jie, Qing Yuan Wang, Ren Hui Tian, and Xiao Zhao. "Low Cycle Tension-Tension Fatigue Properties of 316L Stainless Steel Thin Sheets." Applied Mechanics and Materials 138-139 (November 2011): 832–35. http://dx.doi.org/10.4028/www.scientific.net/amm.138-139.832.
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In this paper, tensile fatigue properties of 316L stainless steel thin sheets with a thickness of 0.1 mm are studied. The tests are implemented by using micro mechanical fatigue testing sysytem (MMT-250N) at room temperature under tension-tension cyclic loading. The S-N curve of the thin sheets descends continuously at low cycle region. Cyclic σ-N curve and ε-N curve are obtained according to the classical macroscopical fatigue theory. The results agree well with the experimental fatigue data, showing that the traditional fatigue research methods are also suitable for description of MEMS fatigue in a certain extent. The effect factor of frequency was considered in this study and the results show that the fatiuge life and the fatigue strength are increased as loading frequency increasing.
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Geenen, R. "PARE0022 TARGETING FATIGUE IN RHEUMATOID ARTHRITIS: A SELF-HELP BOOKLET." Annals of the Rheumatic Diseases 79, Suppl 1 (June 2020): 1296.1–1297. http://dx.doi.org/10.1136/annrheumdis-2020-eular.1123.
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Background:Fatigue in rheumatoid arthritis (RA) is prevalent, intrusive, and disabling [1-3]. It has been shown that fatigue can be reduced, in at least some people with rheumatoid arthritis, using group interventions based on cognitive-behavioral principles [1]. However, the vast majority of the (about 40% [2]) severely fatigued people with rheumatoid arthritis does not have or does not want access to group therapy.Objectives:To develop a self-help booklet aimed at targeting fatigue in rheumatoid arthritis based on cognitive-behavioral principles.Methods:Based on the assumption that the most strongly influencing factors of fatigue differ between people [3], a comprehensive patient-centered approach was chosen. The booklet should be easy to read (big fonts, text boxes, bulleted text, and illustrations). Needed materials should be included.Results:In the booklet, factors that may influence fatigue are demonstrated by a hanging mobile toy, a device with stars or other figures hanging from the ceiling. If one piece moves, all the other pieces move as well. Every individual piece that is part of the mobile influences the other. However, every mobile is different. The large differences in balance between components of mobiles can be compared to the large variety of influences on fatigue in people. Patients first need to identify which factors seem especially important influencers of their own fatigue by sorting seven cards that are included in the booklet. They put the factor of which they think that it most influences their fatigue at the top and the factor that least influences their fatigue at the bottom. The seven cards are:1) severe overweight,2) disease activity,3) day-night rhythm and sleep,4) physical activity,5) emotions and negative thoughts,6) pain, and7) another influence.Interventions targeting these factors are discussed in separate sections of the booklet. Users are invited to start reading the sections with advice regarding the factors that most influence their fatigue. The foldable back cover of the booklet includes the set of seven cards of influencing factors, a diagram to make a 7-day 24-hours day-night rhythm schedule, and instructions to make an action plan.Conclusion:In the Netherlands, the text can be obtained online and as a booklet in rheumatology departments of hospitals and through a national patient association, free of charge. The booklet was translated into English, which makes it accessible to a larger group of patients. It may take up to two months to successfully change lifestyle. It’s an, as yet not empirically verified, hope that the booklet will be more successful than a traditional educational brochure.References:[1]Hewlett S, Almeida C, Ambler N, et al. Reducing arthritis fatigue impact: two-year randomised controlled trial of cognitive behavioural approaches by rheumatology teams (RAFT). Ann Rheum Dis 2019;78(4):465–472.[2]Overman CL, Kool MB, Da Silva JA, Geenen R. The prevalence of severe fatigue in rheumatic diseases: an international study. Clin Rheumatol 2016;35(2):409–415.[3]Geenen R, Dures E. A biopsychosocial network model of fatigue in rheumatoid arthritis: a systematic review. Rheumatology (Oxford) 2019;58(Supplement_5):v10–v21.Disclosure of Interests:Rinie Geenen Speakers bureau: Sanofi Genzyme paid for a lecture on depression in RA.
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WHITE, P. D., J. M. THOMAS, P. F. SULLIVAN, and D. BUCHWALD. "The nosology of sub-acute and chronic fatigue syndromes that follow infectious mononucleosis." Psychological Medicine 34, no. 3 (April 2004): 499–507. http://dx.doi.org/10.1017/s0033291703001302.
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Background. A previous principal components analysis of symptoms occurring after infectious mononucleosis suggested that a discrete fatigue syndrome occurs, which is independent of psychiatric disorder. This work has not been replicated and no latent class analysis of subjects has been published.Method. We prospectively examined a cohort of 150 American primary care patients 2 and 6 months after the onset of corroborated infectious mononucleosis. A subset of 50 subjects was studied 4 years after onset. We performed principal components analyses of both psychological and somatic symptoms and latent class analyses of subjects.Results. Principal components analyses consistently delineated two fatigue factors at 2 and 6 months and one fatigue factor at 4 years. These factors were separate from a mixed anxiety and depressive factor. A four-class solution for the latent class analyses consisted of most subjects with few symptoms, a few with many symptoms, a group with predominantly mood symptoms and some subjects with fatigue symptoms.Conclusions. The symptoms of the principal factors with fatigue were similar to those previously described. Both the factors and classes were independent of an equally delineated mood factor and class. These results support the existence of two discrete chronic fatigue syndromes after infectious mononucleosis, one of which is still demonstrable 4 years after onset.
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Cope, H., A. Mann, A. Pelosi, and A. David. "Psychosocial risk factors for chronic fatigue and chronic fatigue syndrome following presumed viral illness: a case–control study." Psychological Medicine 26, no. 6 (November 1996): 1197–209. http://dx.doi.org/10.1017/s0033291700035923.
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SynopsisThis study investigated psychosocial morbidity, coping styles and health locus of control in 64 cases with and without chronic fatigue identified from a cohort of primary care patients recruited 6 months previously with a presumed, clinically diagnosed viral illness. A significant association between chronic fatigue and psychosocial morbidity, somatic symptoms and escape-avoidance coping styles was shown. Chronic fatigue cases were significantly more likely to have a past psychiatric history and a current psychiatric diagnosis based on a standardized clinical interview. Twenty-three of the cases fulfilled criteria for chronic fatigue syndrome (CFS). Such cases were significantly more fatigued than those not fulfilling criteria, but had little excess psychiatric disorder. A principal components analysis provided some evidence for chronic fatigue being separable from general psychosocial morbidity but not from the tendency to have other somatic complaints. Past psychiatric history and psychological distress at the time of the viral illness were risk factors for psychiatric ‘caseness’ 6 months later, while presence of fatigue, psychologising attributional style and sick certification were significant risk factors for CFS. These findings extend a previous questionnaire study of predictors of chronic ‘post-viral’ fatigue.
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Truyens, Marie, Elodie De Ruyck, Gerard Bryan Gonzales, Simon Bos, Debby Laukens, and Martine De Vos. "Prevalence of Fatigue and Unrecognized Depression in Patients with Inflammatory Bowel Disease in Remission under Immunosuppressants and Biologicals." Journal of Clinical Medicine 10, no. 18 (September 11, 2021): 4107. http://dx.doi.org/10.3390/jcm10184107.
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Background: Although highly prevalent among inflammatory bowel disease (IBD) patients, fatigue remains an unmet clinical need. The aim was to describe the prevalence of fatigue in an IBD population in remission and identify factors associated with fatigue. Methods: IBD patients in clinical and biochemical remission under treatment with immunomodulators or biologicals were included. Fatigue, physical tiredness and depression were assessed using the fatigue Visual Analogue Scale (fVAS), the Shortened Fatigue Questionnaire (SFQ) and the Quick Inventory of Depressive Symptomatology-Self Report (QIDS-SR), respectively. Relevant clinical and biochemical parameters were included in regression analyses to identify factors associated with physical fatigue. Results: In total, 157 IBD patients were included. Up to 45.9% of patients reported fatigue, physical tiredness was observed in 51% and depression in 10.8%. The majority of patients with subclinical depression were fatigued. Female sex (OR = 4.17 [1.55–6.78], p = 0.002) was independently associated with physical fatigue. Transferrin saturation (OR = −0.11 [−0.22–−0.007], p = 0.037) and treatment with adalimumab (compared to infliximab, OR = −3.65 [−7.21–−0.08], p = 0.045) entailed a lower risk of fatigue. Conclusion: Fatigue is observed in about half of IBD patients in remission and can be a symptom of underlying undetected depression. Sex, transferrin saturation and medication were identified as independent risk factors.
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Dharme, Mangesh R., Abhaykumar M. Kuthe, and Tushar R. Deshmukh. "Applied Taguchi Method for Fatigue Testing of Customized Hip Implant." International Journal of Artificial Organs 39, no. 12 (December 2016): 611–18. http://dx.doi.org/10.5301/ijao.5000545.
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Purpose Human activities generate stresses, which vary with time and may result in fatigue failure of the customized hip implant. This study aims to investigate fatigue testing of customized hip implants using the minimum number of experiments by the Taguchi method, for 147 patients. This study was also useful to determine the influential geometrical parameters on the fatigue safety factor of customized hip implants. Methods Horizontal offset (HO), vertical offset (VO) and neck shaft angle (NSA) of the hip joint of 147 patients were measured on computed tomography (CT) scanned images. Stress and strain of hip implants were calculated by finite element analysis and validated by in vitro experimental tests. Fatigue safety factors were calculated by Goodman, Soderberg and Gerber's fatigue theories and maximum stresses. Results Analysis of variance results show that the highest impact on fatigue safety factors was equal to 54.38% for HO, 16.33% for VO, and was equal to 29.16% for NSA with reference to Goodman, Soderberg and Gerber's fatigue theories. The hip implant shape of experiment no. 8 has the highest safety factor value compared to all other hip implants. Conclusions The results show that HO has the maximum influence on fatigue safety factors. The determination of influential geometric parameters may be useful to redesign customized hip implants in order to achieve the highest fatigue safety factor. The Taguchi method is suitable for fatigue testing of custom hip implant with a minimum number of experiments.
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Song, Woojin, Fu L. Woon, Alice Doong, Carol Persad, Louis Tijerina, Pooja Pandit, Carol Cline, and Bruno Giordani. "Fatigue in Younger and Older Drivers: Effectiveness of an Alertness-Maintaining Task." Human Factors: The Journal of the Human Factors and Ergonomics Society 59, no. 6 (May 16, 2017): 995–1008. http://dx.doi.org/10.1177/0018720817706811.
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Objective: The aim of this study was to examine the effects of an alertness-maintaining task (AMT) in older, fatigued drivers. Background: Fatigue during driving increases crash risk, and previous research suggests that alertness and driving in younger adults may be improved using a secondary AMT during boring, fatigue-eliciting drives. However, the potential impact of an AMT on driving has not been investigated in older drivers whose ability to complete dual tasks has been shown to decline and therefore may be negatively affected with an AMT in driving. Method: Younger ( n = 29) and older drivers ( n = 39) participated in a 50-minute simulated drive designed to induce fatigue, followed by four 10-minute sessions alternating between driving with and without an AMT. Results: Younger drivers were significantly more affected by fatigue on driving performance than were older drivers but benefitted significantly from the AMT. Older drivers did not demonstrate increased driver errors with fatigue, and driving did not deteriorate significantly during participation in the AMT condition, although their speed was significantly more variable with the AMT. Conclusion: Consistent with earlier research, an AMT applied during fatiguing driving is effective in improving alertness and reducing driving errors in younger drivers. Importantly, older drivers were relatively unaffected by fatigue, and use of an AMT did not detrimentally affect their driving performance. Application: These results support the potential use of an AMT as a new automotive technology to improve fatigue and promote driver safety, though the benefits of such technology may differ between different age groups.
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Feldthusen, Caroline, and Kaisa Mannerkorpi. "Factors of importance for reducing fatigue in persons with rheumatoid arthritis: a qualitative interview study." BMJ Open 9, no. 5 (May 2019): e028719. http://dx.doi.org/10.1136/bmjopen-2018-028719.
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ObjectivePhysical activity plays an important role in the treatment of persons with rheumatoid arthritis (RA) and is the non-pharmacological intervention with the strongest evidence to reduce fatigue. However, physical activity can be challenging for persons who are fatigued. The aim of this study was to investigate factors of importance for reducing fatigue in persons with RA.DesignThis is a qualitative interview study based on semistructured, indepth individual interviews. Interviews were analysed using qualitative content analysis.ParticipantsParticipants were 12 people with RA recruited from a previous randomised controlled trial of a person-centred treatment model focusing on health-enhancing physical activity and daily balance to lessen fatigue in persons with RA.SettingInterviews were conducted in a hospital setting.ResultsThe analysis resulted in one theme:an intellectual and embodied understanding that sustainable physical activity is important to handle fatigue. This included five categories describing barriers and facilitating factors for sustainable physical activity:mentally overcoming the fatigue in order to be active,making exercise easy,reaching for balance,receiving support to be physically activeanddealing with RA disease to be physically active.ConclusionThe participants in this study expressed that physical activity was important in handling fatigue, but also that this insight could only come from personal experience. The use of a person-centred ethic in physiotherapy coaching for patients with fatigue appears to promote sustainable physical activity behaviours by facilitating patients’ resources to overcome barriers to physical activity.
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SHI, GUANGLIN, LIN ZHU, and DONGBIN WEI. "A NEW PREDICTION APPROACH FOR THE STRUCTURAL FATIGUE LIFE BASED ON MULTI-FACTOR CORRECTION." Surface Review and Letters 25, no. 05 (July 2018): 1850095. http://dx.doi.org/10.1142/s0218625x18500956.
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As the phenomenon of fatigue damage is a common failure mode of equipment, the reliability evaluation and life prediction have become a hot-spot. The precise prediction of fatigue life in the initiation stage has become necessary. The common prediction study for structural fatigue life takes less influence factors into consideration. The common prediction results of fatigue life cannot be quantitatively corrected by the influence factors at the same time. This paper presents a research on the prediction approach for structural fatigue life based on the multi-factor correction. The influence of some factors on the fatigue life was analyzed and the prediction approach for structural fatigue life based on multi-factor correction was raised. Then the fatigue life of axle housing was predicted by using the corrected approach, as the case study. Moreover, the result predicted by the local stress–strain approach and the experimental data were used to verify the accuracy of the corrected approach. It can be clearly demonstrated by the results that the corrected prediction approach can be used to achieve the precision fatigue life for engineering structures. Further, it is also a prediction approach endowed with engineering application prospects.
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Avakov, V. A. "Safety Factor in Fatigue Under Fluctuating Stresses." Journal of Vibration and Acoustics 109, no. 4 (October 1, 1987): 397–401. http://dx.doi.org/10.1115/1.3269459.
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It is common to assume identical allowable safety factors in static strength [m], defined by mean stress (Sm), and in fatigue [a], defined by stress amplitude (Sa), in order to find the full safety factor (F) under asymmetrical cycles, or to plot any type of the Sm–Sa diagram of allowable stresses. Here additional modification is considered to generalize expression of the full factor of safety in fatigue under asymmetrical stresses, utilizing unequal allowable safety factors in static strength (by mean stress) and in fatigue (by stress amplitude): ([a] ≠ [m]). We assume that loading is stationary, and cumulated number of cycles is large enough to consider high cycle fatigue.
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Li, You Tang, Zhi Yuan Rui, and Chang Feng Yan. "Effect of Wear on the Fatigue Life of Annular Notched Shaft Based on Product Lifecycle Management." Key Engineering Materials 417-418 (October 2009): 469–72. http://dx.doi.org/10.4028/www.scientific.net/kem.417-418.469.
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Anti-fatigue design is a key content in product lifecycle management and there are many factors to affect the fatigue life of parts. For designing the fatigue life of shaft with a circumferential notch exactly, the influencing factors have been analyzed completely. The mechanics model for assessing the fatigue life of shaft is set up. The assessment method of fatigue life for shaft is set up according to the traditional fatigue life estimation. The effect of wearing parameter to fatigue life is analyzed and the results show that the wear is an important factor to affect the fatigue life.
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Bendix, Laila, Mikael Thinggaard, Masayuki Kimura, Abraham Aviv, Kaare Christensen, Merete Osler, and Kirsten Avlund. "Association of Leukocyte Telomere Length with Fatigue in Nondisabled Older Adults." Journal of Aging Research 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/403253.
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Introduction. Fatigue is often present in older adults with no identified underlying cause. The accruing burden of oxidative stress and inflammation might be underlying factors of fatigue. We therefore hypothesized that leukocyte telomere length (LTL) is relatively short in older adults who experience fatigue.Materials and Methods. We assessed 439 older nondisabled Danish twins. LTL was measured using Southern blots of terminal restriction fragments. Fatigue was measured by the Mob-T Scale based on questions on whether the respondents felt fatigued after performing six mobility items.Results. LTL was significantly associated with fatigue (P=0.023), showing an increase of 0.038 kb/fatigue score unit. Aging-related diseases and mental health did not explain the association, while lifestyle factors slightly attenuated the estimates.Conclusion. Our results support an association between LTL and fatigue. Further studies are required to confirm this finding and the link of LTL with oxidative stress/inflammation over the life course.
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Chilcot, Joseph, Sam Norton, Maedhbh Etain Kelly, and Rona Moss-Morris. "The Chalder Fatigue Questionnaire is a valid and reliable measure of perceived fatigue severity in multiple sclerosis." Multiple Sclerosis Journal 22, no. 5 (July 31, 2015): 677–84. http://dx.doi.org/10.1177/1352458515598019.
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Background: Fatigue is one of the most distressing symptoms of multiple sclerosis (MS). Measuring MS fatigue poses a number of challenges. Many measures confound definitions of severity and impact of fatigue and/or lack psychometric validation in MS. Objective: To evaluate the psychometric properties of an 11-item fatigue severity measure, the Chalder Fatigue Questionnaire (CFQ) in MS including validity of the factor structure, internal reliability, discriminant validity and sensitivity to change. Methods: Data were pooled from four previous studies investigating MS fatigue using the CFQ ( n=444). Data analysis included confirmatory factor analysis to determine the factor structure and model fit, correlations to assess discriminant validity and effects sizes to determine sensitivity to change. Results: A bi-factor model with one general fatigue factor, incorporating two smaller group factors (mental and physical fatigue) had good model fit and appeared the most appropriate factor structure underlying the CFQ scale. The CFQ had high internal consistency, showed small to moderate correlations with impact of fatigue and mood, and was sensitive to change across low and high intensity behavioural interventions. Conclusions: The CFQ measuring a composite of physical and mental fatigue severity (i.e. a total score) is a psychometrically sound measure of fatigue severity in MS.
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Syahfudin, Andy Juniar. "The Description of Internal and External Factors of Fatigue at Sidoarjo Steel Smelting Company." Indonesian Journal of Occupational Safety and Health 8, no. 3 (December 27, 2019): 336. http://dx.doi.org/10.20473/ijosh.v8i3.2019.336-345.
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Introduction: Work fatigue or fatigue is a kind of body prevention from further damages. The fatigue experienced by a worker resulted in a decrease in work performance and lack of body endurance during the work. The workers of steel smelting companies are one of the examples of workers who potentially experience work fatigue. This research aims to ascertain both the internal and external factors of work fatigue experienced by the workers at Sidoarjo steel smelting company. Methods: This research was conducted at Sidoarjo steel smelting company in May 2018 with a population of 30 people. The internal factors in this research are the age, years of service, and nutritional status of the workers. Meanwhile, the external factors are the physical workload, work climate, and noise. This research is descriptive research with observation as the data collection method and is cross-sectional research design. The sample is calculated by applying the total population sampling technique. The data is presented descriptively in the form of frequency, percentage, and cross-tabulation among variables distributions. Result: It is revealed that the majority of the workers, as many as 17 people, undergo mild work fatigue (56.7%). The results of the cross-tabulation show that moderate and severe fatigues are mostly experienced by the workers with these criteria: younger, shorter years of service, obese, fair physical workload, and work climate and noise that exceed the Threshold Limit Value (TLV). Conclusion: It is affirmed that both the internal and external factors are related to work fatigue. Keywords: external factors, internal factors, steel smelting, work fatigue
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Syahfudin, Andy Juniar. "The Description of Internal and External Factors of Fatigue at Sidoarjo Steel Smelting Company." Indonesian Journal of Occupational Safety and Health 8, no. 3 (December 27, 2019): 336. http://dx.doi.org/10.20473/ijosh.v8i3.2019.341-351.
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Introduction: Work fatigue or fatigue is a kind of body prevention from further damages. The fatigue experienced by a worker resulted in a decrease in work performance and lack of body endurance during the work. The workers of steel smelting companies are one of the examples of workers who potentially experience work fatigue. This research aims to ascertain both the internal and external factors of work fatigue experienced by the workers at Sidoarjo steel smelting company. Methods: This research was conducted at Sidoarjo steel smelting company in May 2018 with a population of 30 people. The internal factors in this research are the age, years of service, and nutritional status of the workers. Meanwhile, the external factors are the physical workload, work climate, and noise. This research is descriptive research with observation as the data collection method and is cross-sectional research design. The sample is calculated by applying the total population sampling technique. The data is presented descriptively in the form of frequency, percentage, and cross-tabulation among variables distributions. Result: It is revealed that the majority of the workers, as many as 17 people, undergo mild work fatigue (56.7%). The results of the cross-tabulation show that moderate and severe fatigues are mostly experienced by the workers with these criteria: younger, shorter years of service, obese, fair physical workload, and work climate and noise that exceed the Threshold Limit Value (TLV). Conclusion: It is affirmed that both the internal and external factors are related to work fatigue. Keywords: external factors, internal factors, steel smelting, work fatigue
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Zhao, Rong Guo, Xiu Juan Li, Yong Zhou Jiang, Xi Yan Luo, Jun Fei Li, Hong Chao Li, and Dun Hou Tan. "Experimental Study and Numerical Simulation on Fatigue Crack Growth Behavior of GH4133B Superalloy." Key Engineering Materials 512-515 (June 2012): 980–88. http://dx.doi.org/10.4028/www.scientific.net/kem.512-515.980.
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The fatigue crack growth tests for nickel-based GH4133B superalloy used in turbine disk of a type of aero-engine are carried out at room temperature. The stress intensity factor ranges and the fatigue crack growth rates at various stress ratios are measured, and the corresponding threshold stress intensity factor ranges are determined. Using the Paris formula, the experiment data of fatigue crack growth are analyzed. It is shown that the fatigue crack growth rate increasing with increasing stress intensity factor range and stress ratio, and a modified Paris formula considering threshold stress intensity factor range can describe the fatigue crack growth behavior precisely. The fracture surface morphologies are investigated using a scanning electron microscope. It is shown that in the crack initiation region, steady growth region and rapid growth region, the fracture surface exhibits a cleavage fracture mode, fatigue striations and an intergranular fracture mode, respectively. Finally, the von Mises stresses and stress intensity factors at the crack tip of specimen of GH4133B superalloy at various external loads and crack lengths are simulated using the finite element method, and the threshold stress intensity factors under different maximal external loads at a certain crack length are calculated. The comparison between test and simulation indicates that the stress intensity factors at the crack tip calculated by the finite element method agree well with experimental data.
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Derikx, L., S. Siakavellas, L. Derr, L. Williams, P. Nikolas, P. Jenkinson, L. Lucaciu, et al. "OP22 Factors independently associated with fatigue in IBD: Results from the baseline dataset of the PREdiCCt study." Journal of Crohn's and Colitis 15, Supplement_1 (May 1, 2021): S021. http://dx.doi.org/10.1093/ecco-jcc/jjab075.021.
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Abstract Background Fatigue is one of the most common symptoms in IBD resulting in decreased quality of life, impaired work productivity, and higher societal costs. However, little is known about its etiology and pathophysiology. We aimed to estimate the prevalence of fatigue and to identify predictive factors for fatigue. Methods The PREdiCCt study (https://www.predicct.co.uk) is the largest prospective study of the causes of IBD flare. 2629 patients in clinical remission were recruited from 48 UK sites. 1946 (74%) patients completed the baseline questionnaires. We assessed the prevalence of fatigue at baseline using a single item from the IBD Control questionnaire. To identify predictors for fatigue, we performed univariable and multivariable analyses including demographic, biochemical, environmental and psychosocial factors such as anxiety and depression [HADS], sleep quality [PSQI] and physical exercise [GPAQ]). Results 759/1919 IBD patients in clinical remission (39.6%) reported fatigue in the past 2 weeks, while 1034 patients (53.9%) did not report fatigue. Patients who reported fatigue were more frequently female, had more frequently CD, and were more frequently smokers (Table 1). Univariable comparisons showed higher inflammatory markers in the fatigued group, with fewer patients in clinical remission. Multivariable analyses identified female sex (OR 2.4), CRP>5 (OR 2.1), bad sleep quality (OR 2.5), anxiety (OR 1.8) and depression (OR 6.2) as independent factors associated with fatigue (Table 2). Conclusion We show the significant burden of fatigue in IBD patients and describe putative causes which demonstrate both the impact of residual gut inflammation and the relationship between fatigue and psychological well-being. The impact of environmental and dietary factors on fatigue is being further investigated with ongoing longitudinal data collection in the PREdiCCt study.
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Gagnon, Philippe, Didier Saey, Isabelle Vivodtzev, Louis Laviolette, Vincent Mainguy, Julie Milot, Steeve Provencher, and François Maltais. "Impact of preinduced quadriceps fatigue on exercise response in chronic obstructive pulmonary disease and healthy subjects." Journal of Applied Physiology 107, no. 3 (September 2009): 832–40. http://dx.doi.org/10.1152/japplphysiol.91546.2008.
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Exercise intolerance in chronic obstructive pulmonary disease (COPD) results from a complex interaction between central (ventilatory) and peripheral (limb muscles) components of exercise limitation. The purpose of this study was to evaluate the influence of quadriceps muscle fatigue on exercise tolerance and ventilatory response during constant-workrate cycling exercise testing (CWT) in patients with COPD and healthy subjects. Fifteen patients with COPD and nine age-matched healthy subjects performed, 7 days apart, two CWTs up to exhaustion at 80% of their predetermined maximal work capacity. In a randomized order, one test was performed with preinduced quadriceps fatigue and the other in a fresh state. Quadriceps fatigue was produced by electrostimulation-induced contractions and quantified by maximal voluntary contraction and potentiated twitch force (TwQpot). Endurance time and ventilatory response during CWT were compared between fatigued and fresh state. Endurance time significantly decreased in the fatigued state compared with the fresh condition in COPD (356 ± 69 s vs. 294 ± 45 s, P < 0.05) and controls (450 ± 74 s vs. 340 ± 45 s, P < 0.05). Controls showed significantly higher ventilation and end-exercise dyspnea scores in the fatigued condition, whereas, in COPD, fatigue did not influence ventilation or dyspnea during exercise. The degree of ventilatory limitation, as expressed by the V̇e/maximum voluntary ventilation ratio, was similar in both conditions in patients with COPD. We conclude that it is possible to induce quadriceps fatigue by local electrostimulation-induced contractions. Our findings demonstrate that peripheral muscle fatigue is an additional important factor, besides intense dyspnea, that limits exercise tolerance in COPD.
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Borren, Nienke Z., William Tan, Francis P. Colizzo, Jay Luther, John J. Garber, Hamed Khalili, C. Janneke van Der Woude, and Ashwin N. Ananthakrishnan. "Longitudinal Trajectory of Fatigue With Initiation of Biologic Therapy in Inflammatory Bowel Diseases: A Prospective Cohort Study." Journal of Crohn's and Colitis 14, no. 3 (August 26, 2019): 309–15. http://dx.doi.org/10.1093/ecco-jcc/jjz148.
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Abstract Backgrounds and Aims Fatigue is prevalent in patients with inflammatory bowel diseases [IBD]. Biologic therapy is effective in achieving symptomatic and endoscopic remission, but its impact on fatigue is less well established. Our aim is to define the longitudinal trajectory of fatigue over 1 year in patients initiating biologic therapy. Methods This prospective cohort enrolled patients diagnosed with Crohn’s disease [CD] or ulcerative colitis [UC] initiating biologic therapy with infliximab, adalimumab, ustekinumab, or vedolizumab. Fatigue was quantified using the seven-point fatigue question in the Short Inflammatory Bowel Disease Questionnaire [SIBDQ]. A score of ≤4 for this question was used to define fatigue. Multivariable regression models adjusting for relevant confounders examined the independent association between attaining clinical remission and resolution of fatigue. Results Our study included 326 patients [206 CD, 120 UC] initiating biologic therapy [144 anti-tumour necrosis factor, 129 vedolizumab, 63 ustekinumab]. A total of 61% of the included patients reported significant fatigue at baseline. This was associated with female gender, depressive symptoms, active disease, and disturbed sleep [p < 0.001]. Among the 198 patients who were fatigued at therapy initiation, 86 [70%], 55 [63%], and 44 [61%] remained fatigued at Week 14, 30, and 54, respectively. At each of these time points, achieving clinical remission was associated with lower likelihood of persistent fatigue. However, despite achieving remission, 35%, 30%, and 28% of patients experienced persistent fatigue at Week 14, 30, and 54, respectively. Conclusions Fatigue is common in IBD. Though biologic therapy improves fatigue parallel symptomatic improvement, a significant proportion continue to experience persistent fatigue up to 1 year.
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Li, Fan, Chun-Hsien Chen, Gangyan Xu, Danni Chang, and Li Pheng Khoo. "Causal Factors and Symptoms of Task-Related Human Fatigue in Vessel Traffic Service: A Task-Driven Approach." Journal of Navigation 73, no. 6 (June 23, 2020): 1340–57. http://dx.doi.org/10.1017/s0373463320000326.
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Human fatigue is a major risk factor in transportation that contributes, directly or indirectly, to a large number of traffic accidents. Though many studies have investigated fatigue-inducing factors in transportation to manage human fatigue more efficiently, there are limited studies related to vessel traffic service (VTS). To fill this gap, this work aims to determine the key causal factors and symptoms of human fatigue with a focus on VTS operations. Achieving this aim is hindered by the problems of no standard definition of task-related fatigue and limited data sources. To solve these problems, this paper proposes a novel definition of task-related human fatigue, a task-driven approach for identifying causal factors and a causal network-based approach for selecting key causal factors. Twelve key causal factors of human fatigue in VTS were identified and analysed. In addition, it was found that VTS operators suffered from multidimensional fatigue, especially physical fatigue. The results provide a foundation and future directions for designing interventions to manage human fatigue.
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Birenis, Domas, Yuhei Ogawa, Hisao Matsunaga, Osamu Takakuwa, Junichiro Yamabe, Øystein Prytz, and Annett Thøgersen. "Hydrogen-assisted fatigue crack propagation in a pure BCC iron. Part II: Accelerated regime manifested by quasi-cleavage fracture at relatively high stress intensity range values." MATEC Web of Conferences 165 (2018): 03010. http://dx.doi.org/10.1051/matecconf/201816503010.
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Hydrogen effect on fatigue performance at relatively high values of stress intensity factor range, ΔK, of pure BCC iron has been studied with a combination of various electron microscopy techniques. Hydrogen-assisted fatigue crack growth rate is manifested by a change of fracture features at the fracture surface from ductile transgranular in air to quasi-cleavage in hydrogen gas. Grain reference orientation deviation (GROD) analysis has shown a dramatic suppression of plastic deformation around the crack wake in samples fatigued in hydrogen. These results were verified by preparing site-specific specimens from different fracture features by using Focused Ion Beam (FIB) technique and observing them with Transmission Electron Microscope (TEM). The FIB lamella taken from the sample fatigued in air was decorated with dislocation cell structure indicating high amount of plasticity, while the lamella taken from the quasi-cleavage surface of the sample fatigued in hydrogen revealed a distribution of dislocation tangles which corresponds to smaller plastic strain amplitude involved at the point of fracture. These results show that a combination of critical hydrogen concentration and critical stress during fatigue crack growth at high ΔK values triggers cleavage-like fracture due to reduction of cohesive force between matrix atoms.
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Brueckner-Foit, Angelika, Pascal Pitz, Phillip Grahlmann, and Frank Zeismann. "Experimental Determination of Crack Driving Forces for Small Cracks." Solid State Phenomena 258 (December 2016): 495–500. http://dx.doi.org/10.4028/www.scientific.net/ssp.258.495.
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The crack tip field of small fatigue cracks was measured using digital image correlation DIC. For this purpose, smooth specimen were fatigued until a certain amount of damage was visible on the surface. This specimens were then placed in a micro-tensile device in the SEM. The grey value patterns obtained at two different load levels were analyzed with DIC. Fitting the Williams series for the crack tip field to the corresponding DIC-displacement field in the crack tip area yielded the mode-I, and the mode-II stress intensity factors together with the T-stresses. It was found that the experimental values of the stress intensity factor were comparatively high with pronounced mode-II contributions.