Fatigue differences between Asian and Western populations in prolonged mentally demanding work-tasks

IntroductionWith an increase in the number of mentally demanding jobs, as well as the increase in work performed while sedentary, there is a growing imbalance in the use of body resources. This often results in an increase in fatigue in the working population. The diversity of the workforce is also increasing, whereas physiological differences based on culture are important to consider. The objective of this study was to identify the differences in the levels of fatigue in the workplace experienced by Asian and Western workers in mentally demanding jobs.MethodEight Asian and eight Western participants completed an observation-based study. Each participant was observed for four hours in their workplace while they were working on highly mentally demanding work-tasks either computer programming or mathematical simulations. To balance the effect of time, half of the participants from each ethnic group were observed in the morning session and the other half in the afternoon session. Perceived fatigue was measured every 30 min using the single dimensional Borg and multidimensional SOFI scales. Workload was measured using NASA-TLX, and as a change in resting heart rate.ResultEthnicity and time interacted to significantly affect the perceived fatigue measured by Borg (F (9,126) = 2.03, p = 0.0412) and SOFI (F(9,126) = 3.28, p = 0.0013) scales. Asian participants reported significantly higher workload measured by NASA-TLX scores (F(1, 14) = 3.68, p = 0.0024) and change in resting heart rate (F(1, 14) = 7.77, p = 0.0145) was measured higher compared to Western participants. Unlike fatigue, no significant interactions were observed between time and ethnicity to affect either NASA-TLX scores or change in resting heart rate. Post-hoc analyses show that the rate of fatigue was higher for Asian participants. Correlations between the dependent variables were significant (p < 0.0001), with a stronger correlation identified for Asian participants.ConclusionAs compared to the Western participants, Asian participants reported higher values in all dependent measures, including fatigue in both scales, NASA-TLX scores, and change in resting heart rate.Relevance to industryThe significant growth in white-collar as well as mentally demanding jobs requires more cognitive resources, while reducing physical activities. The consequences of the imbalances in the use of body resources have yet to be studied. This study has been designed to investigate the issues of imbalance in the workplace.     

Problematic Internet use,loneliness and dating anxiety among young adult university students

The Internet, an important modern means of obtaining information and establishing communication with others, has become an increasingly essential element of human life. Although Internet use makes life easier, it can become problematic in the event of non-functional use. Debate and research into whether Internet addiction is a cause or an effect are continuing. This study investigates problematic Internet use among young adult university students and examines correlation between problematic Internet use and loneliness and dating anxiety. University student Internet use patterns are also investigated. The study was conducted among 493 students from the Karadeniz Technical University Fatih Faculty of Education. The Online Cognition Scale, Dating Anxiety Scale, Loneliness Scale and Personal Information Questionnaire were employed in the collection of data. Pearson correlation analysis, the t-test, one-way analysis of variance and chi-square test were used for data analysis. The Pearson correlation analysis results reveal a significant positive correlation between problematic Internet use and loneliness (r = 0.194, p < 0.001), communication anxiety (r = 0.15, p < 0.001), unpopularity anxiety (r = 0.174, p < 0.001) and physiological symptoms (r = 0.125, p < 0.001) dating anxiety sub-scales. One-way analysis of variance was used to examine whether problematic Internet use varies according to length of Internet use, and a significantly high level of problematic Internet use was observed among those going online for more than 5 h a day compared to other users (F = 14.327, p < 0.001). Chi-square results reveal a significant association between length of Internet use and how students feel when they do not go online (chi-square = 116.543, p < 0.001). The t-test was used to determine whether there was a significant difference in levels of Internet use according to gender, and levels of problematic Internet use were significantly higher among male students than females (t = 4.046, p < 0.001).     

Pack hike test finishing time for Australian firefighters: pass rates and correlates of performance

The pack hike test (PHT, 4.83 km hike wearing a 20.4-kg load) was devised to determine the job readiness of USA wildland firefighters. This study measured PHT performance in a sample of Australian firefighters who currently perform the PHT (career land management firefighters, LMFF) and those who do not (suburban/regional volunteer firefighters, VFF). The study also investigated the relationships between firefighters' PHT performance and their performance across a range of fitness tests for both groups. Twenty LMFF and eighteen age-, body mass-, and height-matched VFF attempted the PHT, and a series of muscular endurance, power, strength and cardiorespiratory fitness tests. Bivariate correlations between the participants’ PHT finishing time and their performance in a suite of different fitness tests were determined using Pearson’s product moment correlation coefficient. The mean PHT finishing time for LMFF (42.2 ± 2.8 min) was 9 ± 14% faster (p = 0.001) than for VFF (46.1 ± 3.6 min). The pass rate (the percentage of participants who completed the PHT in under 45 min) for LMFF (90%) was greater than that of VFF (39%, p = 0.001). For LMFF, VO_2peak in L min⁻¹(r = −0.66, p = 0.001) and the duration they could sustain a grip ‘force’ of 25 kg (r = −0.69, p = 0.001) were strongly correlated with PHT finishing time. For VFF, VO_2peak in mL kg⁻¹ min⁻¹(r = −0.75, p = 0.002) and the duration they could hold a 1.2-m bar attached to 45.5 kg in a ‘hose spray position’ (r = −0.69, p = 0.004) were strongly correlated with PHT finishing time. This study shows that PHT fitness-screening could severely limit the number of VFF eligible for duty, compromising workforce numbers and highlights the need for specific and valid firefighter fitness standards. The results also demonstrate the strong relationships between PHT performance and firefighters’ cardiorespiratory fitness and local muscular endurance. Those preparing for the PHT should focus their training on these fitness components in the weeks and months prior to undertaking the PHT.     

Changes in EEG activity before and after exhaustive exercise in sedentary women in neutral and hot environments

This study examined the effect of hyperthermia on brain electrical activity measured with encephalography during prolonged exhaustive exercise in a group of sedentary women (VO₂max = 35 ± 4 mL kg min⁻¹). Two strenuous cycling exercises were performed either in neutral (N-Ex) or in heat (H-Ex) conditions. Tympanic temperature (Tty), heart rate (HR), body mass loss (BML), plasma volume decrease, and brain electrical activity [EEG: α (8–13 Hz) and β(13–30 Hz)-band and α/β index of fatigue: the ratio between EEG activity in the α band and β-band] were recorded throughout the cycling sessions. The Tty increase 1.0 °C in the N-Ex and 1.8 °C in H-Ex. HR increased in both sessions but with significantly higher values during the H-Ex session when compared with the N-Ex session (p < 0.001) (from 85 ± 4 beats min⁻¹ to 164 ± 6 beats min⁻¹ and from 83 ± 6 beats min⁻¹ to 181 ± 8 beats min⁻¹, respectively in N-Ex and in H-Ex). This was associated with a significantly higher BML (p < 0.05) and a higher plasma volume decrease in the H-Ex session (p < 0.01). The α/β index increased significantly during both trials particularly during the H-Ex session (p < 0.05). This was associated with a significant decrease of time to exhaustion (−34%). We suggest that exhausting work in the heat induced a change in gross brain activity (alpha/beta ratio) compared to a longer, less thermally demanding exposure. Fatigue in the heat could be attributed to central factors as well as thermal, cardiac and hydro-electrolytic impairment.     

Back pain arising from schoolbag usage among primary schoolchildren

This study employed multifactorial variables to determine the effect of schoolbag weight on the occurrence of back pain among primary schoolchildren and also determined the reliability and factorability of their survey responses. A total of 615 prepubescent children aged between 7 and 12 years with a boy to girl ratio of 2:3 participated in the study. Of these children, 205 were also selected for a test–retest to determine the reliability of the questionnaire. The kappa coefficient was used to analyze dichotomous and nominal variables, and the intraclass correlation coefficient (ICC) was used for the categorical variables. Correlation techniques were also used to investigate backpack-induced back pain problems. The test–retest revealed that dichotomous and demographic (k = 0.7–1.0), psychosocial perception of pain (ICC = 0.6–0.72) and backpack culture (ICC = 0.6–0.78) variables all demonstrated good and high reliability. Variables associated with multiple responses, however, recorded low reliability value. The exploratory factor analysis also reveals six factors, of which only psychosocial perception of pain, individual rating ability and backpack culture accounted for more than 70% of the variance explained during the analysis. Both the subjective and objective variables revealed the significant effect of the children's heavy bag on their degree of feeling back pain (F(2,612) = 3.72, p = 0.02), neck inclination (F(2,166.15) = 54.8, p < 0.0001), back inclination (F(2,183.9) = 60.92, p < 0.0001), pulse rate (F(2,155.31) = 4.07, p = 0.019) and saturated oxygen (F(2,152.83) = 5.95, p = 0.003) were significantly associated with the weight of their schoolbags. The significant effect of age was also identified as the measuring variables were all negatively correlated with the children's age. Backpack–back pain intervention and awareness are still needed especially among the younger primary schoolchildren who are at greater risk of back pain from backpack usage.     

Development of a tablet test for the precision assembly efficiency assessment

This study explored if an individual's aiming ability can be used to predict his or her overall performance in a precision assembly task. A tablet aiming test was developed. Ten participants in the Pilot group was asked to do both the tablet aiming test and the simulated assembly task to determine the number of trials that were required for participants to get familiar with each operation. Thirty participants in the Test group performed the both tasks at certain times based on the number of trials determined in the pilot test. Pearson correlation analysis shows that, among the seven performance measures extracted from the tablet aiming test, the Number of Miss (r = 0.39, p = 0.03), the Hit Rate (r = −0.38, p = 0.04), and the Miss Rate (r = 0.39, p = 0.03) each had a significant correlation with the time required to complete the simulated assembly task (p < 0.05). The findings provide insights into the potential development for predicting the efficiency of a precision assembly task.     

Non-anthropomorphic robots as social entities on a neurophysiological level

The mirror-neuron-system (MNS) is involved in the perception of actions of humans and anthropomorphic robots. The current study investigates whether social interaction with a non-anthropomorphic robot is sufficient for a response of the MNS.Fifty-seven participants observed movements of a vacuum cleaning robot before and after it was handled by its owner. The robot was either humanized, being treated aggressively (n = 30), or it was treated as an object (n = 27). Electroencephalographic mu-activity is used as an index of MNS activity, because both are inversely correlated. Activity within the 8–13 Hz band was measured at central (mu-activity) and occipital (alpha-activity) electrodes. Further, the level of aggressiveness displayed by the robot's owner, and the participants' compassion were rated on visual analog scales.Mu-activity showed medium-sized correlations with rated aggressiveness and compassion: The more aggressive the action towards the robot was perceived (r = −.379, p = .004), and the more compassion was felt for the robot (r = −.339, p = .010), the less pronounced mu-activity was at electrode C3 in response to the robot's movement.Thus social interaction with a non-anthropomorphic robot might establish the robot as a social entity and is sufficient to activate the human MNS.     

Utilizing slope method as an alternative data analysis for functional near-infrared spectroscopy-derived cerebral hemodynamic responses

The purpose was to propose an alternative data analysis for functional near-infrared spectroscopy (fNIRS)-derived hemodynamics as a function of cortical activation changes. We evaluated hemodynamic responses from the prefrontal cortex region while 38 participants performed a cognitive task. The task consisted of an arithmetic calculation with three levels of complexity (i.e., easy, medium and difficult). These task-dependent hemodynamic responses were analyzed by the slope method (i.e. using a linear regression through the cognitive task) and were compared with the corresponding responses obtained with a traditional approach of the amplitude method. Subjective scales of task loading (assessed by DP15 and NASA-TLX) and behavioral outcomes (performance and reaction time) were also recorded in response to the task complexity. Results revealed that the proposed slope method allowed a better discrimination in terms of cortical activation among all levels of mental workload. There was no significant increase in cortical activation between the medium and difficult levels (p = .30; d = 0.09) with the amplitude method while the slope coefficient was sensitive to the different levels (p < .01; d = 0.32). These preliminary results from a large sample size demonstrated that the slope method appears suitable for discriminating the changes in cortical activation with respect to the mental workload.Relevance to industryIn this work, we proposed an optimum way of quantifying the mental workload of participants in terms of fNIRS-derived cerebral hemodynamic responses.     

Knowledge sharing and social media: Altruism,perceived online attachment motivation,and perceived online relationship commitment

Social media, such as Facebook and Twitter, have become extremely popular. Facebook, for example, has more than a billion registered users and thousands of millions of units of information are shared every day, including short phrases, articles, photos, and audio and video clips. However, only a tiny proportion of these sharing units trigger any type of knowledge exchange that is ultimately beneficial to the users. This study draws on the theory of belonging and the intrinsic motivation of altruism to explore the factors contributing to knowledge sharing behavior. Using a survey of 299 high school students applying for university after the release of the public examination results, we find that perceived online attachment motivation (β = 0.31, p < 0.001) and perceived online relationship commitment (β = 0.49, p < 0.001) have positive, direct, and significant effects on online knowledge sharing (R² 0.568). Moreover, when introduced into the model, altruism has a direct and significant effect on online knowledge sharing (β = 0.46, p < 0.001) and the total variance explained by the extended model increases to 64.9%. The implications of the findings are discussed.     

Impact of police body armour and equipment on mobility

Body armour is used widely by law enforcement and other agencies but has received mixed reviews. This study examined the influence of stab resistant body armour (SRBA) and mandated accessories on physiological responses to, and the performance of, simulated mobility tasks. Fifty-two males (37 ± 9.2 yr, 180.7 ± 6.1 cm, 90.2 ± 11.6 kg, VO_2max 50 ± 8.5 ml kg⁻¹ min⁻¹, BMI 27.6 ± 3.1, mean ± SD) completed a running VO_2max test and task familiarisation. Two experimental sessions were completed (≥4 days in between) in a randomised counterbalanced order, one while wearing SRBA and appointments (loaded) and one without additional load (unloaded). During each session participants performed five mobility tasks: a balance task, an acceleration task that simulated exiting a vehicle, chin-ups, a grappling task, and a manoeuvrability task. A 5-min treadmill run (zero-incline at 13 km·h⁻¹, running start) was then completed. One min after the run the five mobility tasks were repeated.     

Biomechanical analysis of upper trapezius,erector spinae and brachioradialis fatigue in repetitive manual packaging tasks: Evidence from Chinese express industry workers

This study aims to assess the effects of repetitive motion-induced fatigue during manual packaging on kinematics and muscle activity of the arm, back and shoulder. Eighteen participants performed a 60-min manual packaging task. Electromyography median frequency of RUT, RES, LES and RB decreased by 13.2% (p < 0.05), 12.8% (p < 0.05), 11.3% (p < 0.05) and 21% (p < 0.001), respectively over time. The head flexion and the right upper arm flexion angles significantly (p < 0.001) differed among different packaging sizes, and similar results were observed for left upper arm flexion and rotation. The trunk and pelvis angles significantly (p < 0.05) differed over time under three kinds of packaging. The results showed there was an increase in the rating of perceived exertion from 8.56 to 16.94 (p<0.01) during the task. The outcomes of this study indicate repetitive movements in the manual packaging task resulted in elevated prevalence of muscle discomfort in packaging workers, especially the right brachioradialis. Interventions such as specific work: rest ratios, workplace redesign should be explored to relieve muscle fatigue and discomfort.Relevance to industryFor workers performing repetitive manual packaging tasks, biomechanical analysis of different muscles groups can help in developing appropriate ergonomic interventions.     

Brain processing of vocal sounds in advertising: A functional magnetic resonance imaging (fMRI) study

Using functional magnetic resonance imaging (fMRI), this study aimed at investigating the neural mechanisms associated with human and non-human sounds’ perception in advertising. The study employed a block design paradigm in which participants heard human versus non-human sounds in different sets of advertisements. The results showed that, compared to nonhuman sounds, human sounds elicited greater activation in several areas in or around the primary auditory cortex (t > 5.16, p < 0.001). This result suggests that different types of sounds are processed in different functional brain pathways. The existence of voice-selective areas in the brain lends strong support to the face perception neurocognitive model which proposes that visual, affective and linguistic information are processed in different cortical regions in the brain.     

Frequency of the sit to stand task: An observational study of free-living adults

The sit to stand movement is a key determinant of functional independence. Knowledge of the frequency with which the sit to stand movement is performed throughout the day could inform workplace ergonomics, but has rarely been examined.Healthy adults (n = 140) were recruited from the general population. Free-living activity for each participant was reported using an activity monitor. On average, participants performed 60 (±22) sit to stand movements each day. Participants in indoor sedentary occupations performed significantly more sit to stand movements per day than participants in outdoor active occupations (66 vs. 54; n = 102; p = 0.003). Participants (n = 33) performed significantly more sit to stand movements on working days than on non-working days (65 vs. 55; p = 0.018).This analysis provides contemporary data for sit to stand frequency in a predominantly working population, and demonstrates that work and employment have a significant effect on that frequency.     

Physical workload,trapezius muscle activity,and neck pain in nurses' night and day shifts: A physiological evaluation

The purpose of this study was to compare physical workload, electromyography (EMG) of the trapezius muscle, neck pain and mental well-being at work between night and day shifts in twenty Swiss nurses. Work pulse (average increase of heart rate over resting heart rate) was lower during night (27 bpm) compared to day shifts (34 bpm; p < 0.01). Relative arm acceleration also indicated less physical activity during night (82% of average) compared to day shifts (110%; p < 0.01). Rest periods were significantly longer during night shifts. Trapezius muscle rest time was longer during night (13% of shift duration) than day shifts (7%; p < 0.01) and the 50th percentile of EMG activity was smaller (p = 0.02), indicating more opportunities for muscle relaxation during night shifts. Neck pain and mental well-being at work were similar between shifts. Subjective perception of burden was similar between shifts despite less physical burden at night, suggesting there are other contributing factors.     

Exploring the influence of game design on learning and voluntary use in an online vascular anatomy study aid

This research explores the educational impact of an online study aid-game for studying human vascular anatomy (n = 24) versus a similar non-game study aid (n = 22) and how it relates to medical students' demographic traits and voluntary use over a 35-day period. Hierarchical linear regression models revealed that study aid success rate (a metric for assessing performance through the study aids) was a significant predictor of anatomy test improvement with the game (β = 0.41, p = 0.05), but not for the non-game (β = 0.14, p = 0.56). Our analyses suggest that game mechanics encouraged more specific problem-solving strategies than did the control study aid, leading to greater predictability of learning outcomes. There was a non-significant trend among game treatment participants, who were more likely to complete study tasks than those assigned to the control treatment (p = 0.11). It would appear that students' studying habits had the greatest influence (though opposite in both tools) on level of engagement in study aid use. However, contrary to expectations, self-reported gaming habits did not impact participation. Overall, these findings support the integration of game design into undergraduate study aids as a means of increasing use of supplementary educational tools and assessing knowledge.     

Characterisation of regional skin temperatures in recreational surfers wearing a 2-mm wetsuit

The purpose of this study was to investigate skin temperatures across surfers’ bodies while wearing a wetsuit during recreational surfing. Forty-six male recreational surfers participated in this study. Participants were instrumented with eight wireless iButton thermal sensors for the measurement of skin temperature, a Polar RCX5 heart rate monitor and a 2-mm full wetsuit. Following instrumentation, participants were instructed to engage in recreational surfing activities as normal. Significant differences (p < 0.001) in skin temperature (T_sk) were found across the body while wearing a wetsuit during recreational surfing. In addition, regional skin temperature changed across the session for several regions of the body (p < 0.001), and the magnitude of these changes varied significantly between regions. We show for the first time that significant differences exist in skin temperature across the body while wearing a wetsuit during a typical recreational surfing session. These findings may have implications for future wetsuit design.

Practitioner Summary: This study investigated the impact of wearing a wetsuit during recreational surfing on regional skin temperatures. Results from this study suggest that skin temperatures differ significantly across the body while wearing a 2-mm wetsuit during recreational surfing. These findings may have implications for future wetsuit design.     

Risk of tripping,minimum foot clearance,and step length when crossing a barrier

This study was designed to investigate gait parameters upon crossing a barrier and environmental factors influencing the perceived risk of tripping. These factors included illumination and barrier conditions. Barrier conditions were divided into height, type, and color of the barrier. Illumination conditions included normal and dimmed conditions. Twelve male participants were recruited. They walked on a walkway, moving over a barrier. They gave a subjective rating of risk of tripping (SRRT) both before and after the walk. A research assistant recorded a gait disturbance rating (GDR) of the participant upon barrier crossing. The minimum foot clearance (MFC) of both the leading and lagging foot when moving over the barrier, and the step length of the participant before and after crossing the barrier were calculated. The results indicated that the SRRT, both before and after the walk, was significantly (p < 0.0001) higher when the barrier height increased. Increased barrier height caused significantly (p < 0.0001) higher GDR. The barrier type (p < 0.01) and illumination conditions (p < 0.001) had significant effects on the MFC of both the leading and the lagging foot. The color (p < 0.05) and height (p < 0.05) of the barrier also influenced the MFC of the lagging foot significantly. Step length of the leading foot when crossing the barrier was significantly affected by illumination condition (p < 0.001) and barrier type (p < 0.05). The results of the study are helpful in understanding the mechanisms brought into play when moving over barriers on walkways. They provide meaningful information that will help in reducing trip and fall accidents.     

The effect of internet use on well-being: Meta-analysis

The aim of this meta-analysis study was to investigate the effect of internet use on the components of well-being. Life satisfaction, well-being and self-esteem were evaluated as markers of well-being and their interaction with internet use was assessed. Publications in the literature were collated (N = 281) by investigating articles related to the topic. In light of criteria determined by the researcher, 23 studies were included in the analysis. This study comprised a sample group of 21,054 individuals. The mean age of the sample group was calculated as 20.32 years. According to the results of the analysis using the random effect model, internet use has a significant effect on well-being at low levels (k = 28, r = −0.18, p < 0.001). The components of well-being were used as moderator variables. Results of moderator analysis showed that the well-being components were not significant moderator variables of the effect of internet use on well-being (Qb = 1.34, df = 2, p > 0.05). According to the results of the research, internet use is an effective variable on well-being. The results are discussed in light of the literature.     

Mobile phone use among college students is a sedentary leisure behavior which may interfere with exercise

Research suggests that cell phone use is related to sedentary behavior, that cell phone use during exercise reduces intensity, and that high frequency cell phone users are less fit than other users. Thus, cell phone use appears connected to health and fitness behaviors and should be better understood within this context. The present study investigated the sedentary nature of cell phone use, and examined the likelihood of cellphone use interfering with exercise behavior.DesignA validated survey was administered to a random sample of students from a public US university (N = 226).ResultsMean self-reported cell phone use was 380 min day⁻¹, 87% reported cell phone use primarily occurs while sitting, and 70% of use was for leisure. Cell phone use was positively related to sedentary behavior (β = 0.30, p < 0.001). It was not related to physical activity. However, the likelihood of cell phone use during moderate (p = 0.006) and mild (p < 0.001) intensity exercise increased as cell phone use increased.ConclusionLike other screens (e.g., TVs), cell phone use appears to be a sedentary leisure behavior. Furthermore, high frequency use increases the likelihood that it will occur during exercise, likely lowering exercise intensity.