Ratings Of Fatigue Research Articles

71‐4: Late‐News Paper: Real‐time Measurement for Visual Fatigue Induced by Watching Videos

Accurately find timings when visual fatigue occurs is important to dealt with problems caused by displays. To solve this problem, present study tested the validity of dynamic evaluation through continuous fatigue rating. We found that dynamic rating showed similar results with typical questionnaire and showed significant correlations with optical flow.

A single bout of passive exercise mitigates a mental fatigue-induced inhibitory control deficit.

Sustained cognitive effort associated with the psychomotor vigilance task (PVT) increases objective and subjective measures of mental fatigue and elicits a post-PVT inhibitory control deficit. In contrast, passive exercise wherein an individual's limbs are moved via an external force (i.e., mechanically driven cycle ergometer flywheel) provides a postexercise inhibitory control benefit linked to an exercise-based increase in cerebral blood flow. Here, we examined whether passive exercise performed concurrently with the PVT 'blunts' an inhibitory control deficit. On separate days, participants (N = 27) completed a 20min PVT protocol (control condition) and same duration PVT protocol paired with passive cycle ergometry (passive exercise condition). Prior to (i.e., baseline), immediately after and 30min after each condition inhibitory control was assessed via the antisaccade task. Antisaccades require a goal-directed eye movement (i.e., saccade) mirror-symmetrical to a target and provide an ideal tool for evaluating task-based changes in inhibitory control. PVT results showed that vigilance (as assessed via reaction time: RT) during control and passive exercise conditions decreased from the first to last 5min of the protocol and increased subjective ratings of mental fatigue. As well, in the control condition, immediate (but not 30-min) post-intervention antisaccade RTs were longer than their baseline counterparts-a result evincing a transient mental fatigue-based inhibitory control deficit. For the passive exercise condition, immediate and 30-min post-intervention antisaccade RTs were shorter than their baseline counterparts and this result was linked to decreased subjective ratings of mental fatigue. Thus, passive exercise ameliorated the selective inhibitory control deficit associated with PVT-induced mental fatigue and thus provides a potential framework to reduce executive dysfunction in vigilance-demanding occupations.

0296 Feasibility of a Sleep Health Intervention Mobile App for Long-Term Sleep Tracking and Usability in Cargo Pilots

Abstract Introduction Cargo operations frequently require pilots to cross multiple time zones and operate during the night, both of which are fatigue risks. Operators may benefit from an mobile app that provides individual warnings based on prior sleep history. The SleepTank™ mobile app provides warnings about fatigue risk based on the wearer’s individual sleep data as measured by Fitbit devices. In this pilot study, 10 cargo operators provided feedback about the accuracy and usability of the app and up to 100 days of continuous sleep data. Methods Ten (N=10) experienced cargo pilots from a major operator volunteered to wear a Fitbit Versa 2 or Charge 5 to evaluate the app over three months (June-October 2022). Pilots completed a Qualtrics online survey about their perceptions of the app’s accuracy and usability in October 2022. Data for up to 100 days was extracted at the end of the study period. Sleep data was summed by date to provide a 24-hour estimate of time in bed (TIB24), total sleep time (TST24), daily sleep intervals (DSI), and average sleep efficiency (SE). Changes to sleep behavior over time were explored using mixed model linear regression. Results Cargo pilots (N=10) wore the device with the app for an average of 69±29 days (Range: 25-100 days). Pilots’ TIB24 was 455±111 minutes, TST24 for 400±98 min, and SE was 88±4%. Pilots normally slept once per day (DSI: 1.2±0.5). Pilots’ sleep behavior did not change significantly over the study period (all p> 0.4). All 10 rated the app as being useful, particularly for planning bedtimes and naps. 100% of the pilots rated SleepTank™ as accurate in predicting their fatigue levels. Conclusion Experienced cargo operators in this pilot study exhibited healthy sleep habits that were stable over the study period. Operators found the app useful and felt that app-provided fatigue ratings matched their perceived level of fatigue. App usage was not directly related to changes in objective sleep behavior but did validate operators’ experience of fatigue, which may lead to better identification of fatigue symptoms or proactive sleep planning to avoid periods of fatigue risk in the future. Support (if any) NA

Temporal associations between use of psychoactive substances and somatic symptoms in the daily lives of people with fibromyalgia.

Consumption of psychoactive substances-alcohol, nicotine, caffeine, opioids, and cannabis-is common among people with fibromyalgia. Associations between the use of substances and somatic symptoms could reflect efforts to cope with symptoms, aggravation or alleviation of symptoms after the use of substances, or a combination of these. To date, no study has provided insight into temporal associations between the consumption of psychoactive substances and fluctuations in somatic symptoms. We explored whether changes in ratings of pain and fatigue (mental and physical) predicted the later use of psychoactive substances or vice versa (substance use predicting later change in symptoms). Micro-longitudinal design. Fifty adults (88% female, 86% White, mean age of 44.9 years) with fibromyalgia. Participants completed ecological momentary assessments of substance use, pain intensity, and physical/mental fatigue 5 times per day for 8 days. Results of multilevel models indicated that momentary increases in fatigue showed a consistent association with greater odds of later use of psychoactive substances, whereas momentary increases in pain were related to lower odds of later cannabis and nicotine use and higher odds of later alcohol use. Only nicotine use predicted later mental fatigue. Findings highlight the importance of individualized interventions for symptom management or problems related to the use of psychoactive substances. We observed that although somatic symptoms predicted later use of substances, use of substances did not show appreciable effects with regard to alleviating somatic symptoms in people with fibromyalgia.

Beyond the Lungs: O 2 Supplementation Improves Cerebral Oxygenation and Fatigue during Exercise in Interstitial Lung Disease.

Cerebral hypoxia may exacerbate the perception of fatigue. We previously demonstrated that exercise-related hypoxemia, a hallmark of fibrotic interstitial lung disease ( f -ILD), dose dependently impairs cerebral oxygenation in these patients. It is unknown whether normalizing cerebral oxygenation with O 2 supplementation would be associated with positive changes in a relevant patient-centered outcome during exercise in f -ILD, such as improved perceived fatigue. Fourteen patients (12 males, 72 ± 8 yr, 8 with idiopathic pulmonary fibrosis, lung diffusing capacity for carbon monoxide = 44% ± 13% predicted) performed a constant-load (60% peak work rate) cycle test to symptom limitation (Tlim) breathing medical air. Fourteen controls cycled up to Tlim of an age- and sex-matched patient. Patients repeated the test on supplemental O 2 (fraction of inspired O 2 = 0.41 ± 0.08) for the same duration. Near-infrared spectroscopy and the rating-of-fatigue (ROF) scale assessed prefrontal cortex oxygenation and perceived fatigue, respectively. Patients showed severe exertional hypoxemia (Tlim O 2 saturation by pulse oximetry = 80% ± 8%); they had poorer cerebral oxygenation (e.g., oxy-deoxyhemoglobin difference [HbDiff] = -3.5 ± 4.7 [range = -17.6 to +1.9] vs +1.9 ± 1.7 μmol from rest) and greater fatigue (ROF = 6.2 ± 2.0 vs 2.6 ± 2.3) versus controls under air ( P < 0.001). Reversal of exertional hypoxemia with supplemental O 2 led to improved HbDiff (+1.7 ± 2.4 μmol from rest; no longer differing from controls) and lower ROF scores (3.7 ± 1.2, P < 0.001 vs air) in patients. There was a significant correlation between O 2 -induced changes in HbDiff and ROF scores throughout exercise in f -ILD ( rrepeated-measures correlation = -0.51, P < 0.001). Supplemental O 2 improved cerebral oxygenation during exercise in f -ILD, which was moderately associated with lower ratings of perceived fatigue. Reversing cerebral hypoxia with O 2 supplementation may thus have positive effects on patients' disablement beyond those expected from lower ventilation and dyspnea in this patient population.

MOVEMENT-SPECIFIC CHANGES IN ENERGY EXPENDITURE FOR PERSONS WITH MILD MULTIPLE SCLEROSIS

Background and Purpose In healthy adults and animals, movement speeds are often chosen to reduce the energy expended; thus, is MS-related slowness of walking and arm reaching linked to increased effort costs? Here, we hypothesized that the costs of walking would be higher in MS due to gait-related impairments such as spasticity, balance deficits, or worsened fitness; whereas the costs of seated reaching would be no different due to its divorce from the sensorimotor covariates associated with elevated walking costs and low cardiorespiratory demand. Methods Participants with MS (pwMS) (n=13) and age- and sex-matched controls (HCs) (n=11) first performed a battery of assessments. On two separate days, metabolic rates were measured via indirect calorimetry while participants walked on a treadmill at five speeds (0.6 up to 1.60m/s) and while performing out-and-back reaching movements with the dominant arm at five speeds (approx. 0.1 up to 0.8m/s). Results Neither age, height, nor weight differed between pwMS and HCs. The only metrics that differed between groups were the time to walk 25 feet (slower for pwMS) and fatigue ratings (higher for pwMS). Net metabolic rate (normalized to body mass) increased with walking speed (p<2e-16) and was ∼20.54% higher for pwMS at any speed than HCs (p=0.0185). However, the net rate (normalized to arm mass) was no different between pwMS and HCs at any speed (p=0.911). Elastic net regression techniques reinforced these findings: selecting MS-status as an important predictor of walking metabolic rate, while excluding this variable for predicting reaching rate, even when controlling for many additional factors. Discussion Individuals with MS who have high mobility and low disability may require more energy expenditure to walk, but not for seated reaching movements. Our results suggest that movement slowness occurring with MS is not altogether a consequence of energy conservation. Instead, other mechanisms such as fitness, perceived effort, or reward sensitivity should be investigated for improving mobility. In healthy adults and animals, movement speeds are often chosen to reduce the energy expended; thus, is MS-related slowness of walking and arm reaching linked to increased effort costs? Here, we hypothesized that the costs of walking would be higher in MS due to gait-related impairments such as spasticity, balance deficits, or worsened fitness; whereas the costs of seated reaching would be no different due to its divorce from the sensorimotor covariates associated with elevated walking costs and low cardiorespiratory demand. Participants with MS (pwMS) (n=13) and age- and sex-matched controls (HCs) (n=11) first performed a battery of assessments. On two separate days, metabolic rates were measured via indirect calorimetry while participants walked on a treadmill at five speeds (0.6 up to 1.60m/s) and while performing out-and-back reaching movements with the dominant arm at five speeds (approx. 0.1 up to 0.8m/s). Neither age, height, nor weight differed between pwMS and HCs. The only metrics that differed between groups were the time to walk 25 feet (slower for pwMS) and fatigue ratings (higher for pwMS). Net metabolic rate (normalized to body mass) increased with walking speed (p<2e-16) and was ∼20.54% higher for pwMS at any speed than HCs (p=0.0185). However, the net rate (normalized to arm mass) was no different between pwMS and HCs at any speed (p=0.911). Elastic net regression techniques reinforced these findings: selecting MS-status as an important predictor of walking metabolic rate, while excluding this variable for predicting reaching rate, even when controlling for many additional factors. Individuals with MS who have high mobility and low disability may require more energy expenditure to walk, but not for seated reaching movements. Our results suggest that movement slowness occurring with MS is not altogether a consequence of energy conservation. Instead, other mechanisms such as fitness, perceived effort, or reward sensitivity should be investigated for improving mobility.

CrowbarLimbs: A Fatigue-Reducing Virtual Reality Text Entry Metaphor.

Text entry remains challenging in virtual environments, where users may quickly experience physical fatigue in some body parts using existing methods. In this paper, we propose "CrowbarLimbs," a novel virtual reality (VR) text entry metaphor with two deformable extended virtual limbs. By using a crowbar-like metaphor and placing the virtual keyboard at a user-preferred location based on the user's physical stature, our method can assist the user in placing their hands and arms in a comfortable posture, thus effectively reducing the physical fatigue in various body parts, such as hands, wrists, and elbows. In an initial user study, we found that CrowbarLimbs achieved text entry speed, accuracy, and system usability comparable to those of previous VR typing methods. To investigate the proposed metaphor in more depth, we further conducted two additional user studies to explore the ergonomically user-friendly shapes of CrowbarLimbs and virtual keyboard locations. The experimental results indicate that the shapes of CrowbarLimbs have significant effects on the fatigue ratings in various body parts and text entry speed. Furthermore, placing the virtual keyboard near the user and at half their height can lead to a satisfactory text entry rate of 28.37 words per minute.

Fatigue life assessment of fuselage panel modification based on flight measurement

During the modification of the aircraft fuselage panel, the fatigue performance of the structure changes. To ensure the safety and reliability of commercial aircraft, the fatigue life assessment of the modified structure is required. In this paper, the detailed fatigue rating method was used for fatigue assessment. The strain information of the modified structure during the flight was obtained by installing fiber Bragg grating sensors. Through the finite element analysis, the fatigue critical parts were determined and the measured data before modification were converted into the data after modification. The detailed fatigue ratings of the fatigue critical parts were calculated. The fatigue life of the critical parts was evaluated based on the linear fatigue damage cumulative rule. According to the results, the most critical part was determined, which provides a basis for the determination of the modification plan of the fuselage panel.

The impact of hospital-family integrated continuation nursing based on information technology on patients unhealthy mood, family function and sexual function after cervical cancer surgery.

The objective of this study was to explore the impact on hospital-family integrated continuation care based on information technology on the negative emotions, family function, and sexual function of patients after cervical cancer surgery. The clinical case data onto 114 postoperative cervical cancer patients who were nursing in our hospital from July 2019 to July 2021 were selected and were divided into a control group and an observation group. The control group used routine nursing care, and on this basis, the observation group used information technology as the basis for hospital-family integrated continuation care, and we observed and compared the differences in the 2 groups of patients bad mood, family function, and sexual function. The score of anxiety (P = .017), depression (P = .009), fatigue rating (P = .012), and anger (P < .001) in the observation group after care were significantly lower than those in the control group. Problem solving, role, emotional response, emotional involvement, and family function total score in the observation group after care was significantly lower than those in the control group (P < .05). Sexual desire score, sexual arousal score, vaginal lubrication score, orgasm score, sexual satisfaction score, dyspareunia score, and Female Sexual Function Inventory total scores in the observation and control groups after care were significantly higher than those before care (P < .05). The sexual function scores in the observation group after care was significantly higher than those in the control group (P < .05). The hospital-family integrated continuation care based on information technology is more effective than conventional nursing care for patients after cervical cancer surgery.

Fatigue as a key human factor in complex sociotechnical systems: Vessel Traffic Services.

Vessel Traffic Services (VTS) are considered a subsystem of people, whose mission is to improve the effectiveness and efficiency of maritime transport within the maritime system. VTS operate as a control system where Vessel Traffic Services Operators (VTSOs) must cope with a complex environment to make up for safe and efficient maritime transport, so it is essential to understand how these operators maintain control through adapting to the uncertain and dynamic environment of maritime traffic. This multidisciplinary study explores how human factors within this complex sociotechnical system, means VTS, play a role in maritime safety, specifically focusing on fatigue, which is considered a key variable for VTSOs' performance. In this context, the research has focused on the assessment of fatigue with psychological and operational instruments to highlight the importance of the human element in CSSs. To study the intra and inter-individual differences in fatigue ratings and their relationships with other personal and environmental variables: mental workload, work shifts, reaction time, and hours of usual sleep. The study was conducted in two of the 19 Spanish Maritime Rescue Coordination Centers (MRCCs) with a sample of 23 active VTSOs (82.14% of the staff). Both objective and standardized subjective measures were used to assess fatigue and associated sleepiness (Borg RPE, Nasa-TLX, Stanford Sleepiness Scale, and Self-Assessment Manikin Scale). A significant positive correlation between fatigue and mental workload was found, being more prevalent in the night shift, which shows a bigger variation in these variables. A significant difference was found in the increase in fatigue experienced throughout the shift depending on the hours of usual sleep, being smaller in the group of subjects reporting to sleep more. The human element is key to maritime safety related to Vessel Traffic Services, so it is of paramount importance to consider certain measures to counteract the negative effects of fatigue. A proper organization of duties on/off periods, assessment of work and rest schedules, and the implementation of fatigue management programs based on sleep education are recommended.

Effects of repetitive twice-weekly transcranial direct current stimulations on fatigue and fatigability in people with multiple sclerosis

Fatigue is associated with a dramatically decreased quality of life in people with multiple sclerosis (pwMS). It refers to a constant subjective feeling of exhaustion and performance decline, known as fatigability. However, inconsistency and heterogeneity in defining and assessing fatigue have led to limited advances in understanding and treating MS-associated fatigue. Transcranial direct current stimulation (tDCS) has emerged as a promising, non-pharmaceutical treatment strategy for subjective fatigue. However, whether repetitive tDCS also have long-term effects on time-on-task performance has not yet been investigated. This pseudorandomized, single-blinded, and sham-controlled study investigated tDCS effects on behavioral and electrophysiological parameters. 18 pwMS received eight twice-weekly 30 min stimulations over the left dorsolateral prefrontal cortex. Fatigability was operationalized as time-on-task-related changes in reaction time variability and P300 amplitude. Additionally, subjective trait and state fatigue ratings were assessed. The results revealed an overall decrease in subjective trait fatigue ratings that lasted at least four weeks after the stimulations. However, the ratings declined after both anodal and sham tDCS. No effects were found on subjective state fatigue and objective fatigability parameters. Linear Mixed Models and Bayesian Regression models likewise favored the absence of a tDCS effect on fatigability parameters. The results confirm the complex relationship between MS-associated fatigue and fatigability. Reliable and clinically relevant parameters need to be established to extend the potential of tDCS for treating fatigability. Furthermore, our results indicate that consecutive stimulations rather than twice-weekly stimulations should be the preferred stimulation scheme in future studies.

Acceptability, feasibility and preliminary efficacy of low-moderate intensity Constraint Induced Aphasia Therapy and Multi-Modality Aphasia Therapy in chronic aphasia after stroke

ABSTRACT Background High-intensity Constraint-Induced Aphasia Therapy Plus (CIAT-Plus) and Multi-Modality Aphasia Therapy (M-MAT) are effective interventions for chronic post-stroke aphasia but challenging to provide in clinical practice. Providing these interventions may be more feasible at lower intensities, but comparative evidence is lacking. We therefore explored feasibility, acceptability, and preliminary efficacy of the treatments at a lower intensity. Methods A multisite, single-blinded, randomized Phase II trial was conducted within the Phase III COMPARE trial. Groups of participants with chronic aphasia from the usual care arm of the COMPARE trial were randomized to M-MAT or CIAT-Plus, delivered at the same dose as the COMPARE trial but at lower intensity (6 hours/week × 5 weeks rather than 15 hours/week × 2 weeks). Blinded assessors measured aphasia severity (Western Aphasia Battery-Revised Aphasia Quotient), word retrieval, connected speech, multimodal communication, functional communication, and quality of life immediately post interventions and after 12 weeks. Feasibility and acceptability were explored. Results Of 70 eligible participants, 77% consented to the trial; 78% of randomized participants completed intervention and 98% of assessment visits were conducted. Fatigue and distress ratings were low with no related withdrawals. Adverse events related to the trial (n = 4) were mild in severity. Statistically significant treatment effects were demonstrated on word retrieval and functional communication and both interventions were equally effective. Conclusions Low–moderateintensity CIAT-Plus and M-MAT were feasible and acceptable. Both interventions show preliminary efficacy at a low–moderate intensity. These results support a powered trial investigating these interventions at a low–moderate intensity.

Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome

To assess biobehavioral sex differences in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) utilizing a low burden exercise protocol, 22 females and 15 males with ME/CFS and 14 healthy controls underwent two six-min walk tests. Fifteen daily assessments were scheduled for fatigue and function ratings and heart monitoring. Six-min walk tests were conducted on days 8 and 9. The ME/CFS group showed high self-report fatigue and impaired physical function, whereas healthy controls did not show fatigue or function abnormalities. In patients, no significant post-exercise changes were found for heart rate variability (HRV); however, heart rate decreased in ME/CFS males from Day 14 to Day 15 (p = 0.046). Female patients showed increased fatigue (p = 0.006) after the initial walk test, but a downward slope (p = 0.008) in fatigue following the second walk test. Male patients showed a decrease in self-report work limitation in the days after exercise (p = 0.046). The healthy control group evidenced a decrease in HRV after the walk tests from Day 9–14 (p = 0.038). This pilot study did not confirm hypotheses that females as compared to males would show slower exercise recovery on autonomic or self-report (e.g. fatigue) measures. A more exertion-sensitive test may be required to document prolonged post-exertional abnormalities in ME/CFS.Trial registration: NCT NCT03331419.

A machine learning approach for detecting fatigue during repetitive physical tasks

Prolonged and repetitive stress on muscles, tendons, ligaments, and nerves can have long-term adverse effects on the human body. This can be exasperated while working if the environment and nature of the tasks puts significant strain on the body, which may lead to work-related musculoskeletal disorders (WMSDs). Workers with WMSDs can experience generalized pain, loss of muscle strength, and loss of ability to continue working. Most WMSDs injuries are caused by ergonomic risks, such as repetitive physical movements, awkward postures, inadequate recovery time, and muscular stress. Fatigue can be seen as a detector of ergonomic risk, as the accumulation of fatigue can significantly increase the possibility of injury. Thirty participants completed a series of repetitive physical tasks over a six-hour period while wearing sensors to capture data related to heart rate and movement, while external embedded sensors captured ground reaction and hand exertion force. They also provided subjective ratings of fatigue at the start and end of the experiment. Classifiers for fatigue (high vs low) were constructed using three methods: linear discriminant analysis (LDA), k-nearest neighbor (kNN), and polynomial kernel-based SVM (P-SVM) and were validated using a tenfold cross-validation technique that was repeated a hundred times. Results of our supervised machine learning approach demonstrated a maximum accuracy of 94.15% using P-SVM for the binary classification of fatigue.

Working environment and fatigue among fishers in the north Atlantic: a field study.

This study investigates how Faroese deep-sea fishers' exposure to work-related stressors affects their sleep, sleepiness, and levels of fatigue. Being constantly exposed to the unpredictable and harsh North Atlantic Ocean, having long work hours and split sleep for up to 40 days consecutively, they will arguably suffer from fatigue. One hundred and fifty seven fishers participated in this study, and data was gathered throughout 202 days at sea. Subjective data was collected at the start and end of trips via questionnaires, sleep and sleepiness diaries and supplemented by objective sleep data through actigraphs. Ship movements were logged with a gyroscope connected to a laptop. A noise metre measured each work station and resting area, and noise exposure profiles were calculated based on each participant's activity and location. Linear mixed-effect models investigated the effects of work exposure variables on sleep efficiency, and cumulative link mixed models measured effects on the Karolinska Sleepiness Scale and physical fatigue scale. Time of day followed by ship movement were the exposure variables with the highest impact on the outcome variables of sleep efficiency, sleepiness and physical fatigue. The number of days at sea revealed correlations to outcome variables either by itself or interacting with the sleep periods per day. Crew size, shift system or noise did not impact outcome variables when in the model with other variables. Larger catches improved sleep efficiency but did not affect sleepiness and physical fatigue ratings. The findings indicate a chronically fatigued fisher population, and recommends urgent attention being paid to improving the structure of vessels and installing stabilators for greater stability at sea; work schedules being evaluated for protection of health; and work environments being designed that fulfill human physiological requirements in order to ensure the wellbeing and safety of those at sea.

Translingual neurostimulation combined with physical therapy to improve walking and balance in multiple sclerosis (NeuroMSTraLS): Study protocol for a randomized controlled trial

IntroductionPhysical rehabilitation restores lost function and promotes brain plasticity in people with Multiple Sclerosis (MS). Research groups worldwide are testing the therapeutic effects of combining non-invasive neuromodulation with physical therapy (PT) to further improve functional outcomes in neurological disorders but with mixed results. Whether such devices enhance function is not clear. We present the rationale and study design for a randomized controlled trial evaluating if there is additional benefit to the synergistic pairing of translingual neurostimulation (TLNS) with PT to improve walking and balance in MS. Methods and analysisA parallel group [PT + TLNS or PT + Sham], quadruple-blinded, randomized controlled trial. Participants (N = 52) with gait and balance deficits due to relapsing-remitting or progressive MS, who are between 18 and 70 years of age, will be recruited through patient registries in Newfoundland & Labrador and Saskatchewan, Canada. All participants will receive 14 weeks of PT while wearing either a TLNS or sham device. Dynamic Gait Index is the primary outcome. Secondary outcomes include fast walking speed, subjective ratings of fatigue, MS impact, and quality of life. Outcomes are assessed at baseline (Pre), after 14 weeks of therapy (Post), and 26 weeks (Follow Up). We employ multiple methods to ensure treatment fidelity including activity and device use monitoring. Primary and secondary outcomes will be analyzed using linear mixed-effect models. We will control for baseline score and site to test the effects of Time (Post vs. Follow-Up), Group and the Group x Time interaction as fixed effects. A random intercept of participant will account for the repeated measures in the Time variable. Participants must complete the Post testing to be included in the analysis. Ethics and disseminationThe Human Research Ethics Boards in Newfoundland & Labrador (HREB#2021.085) & Saskatchewan (HREB Bio 2578) approved the protocol. Dissemination avenues include peer-reviewed journals, conferences and patient-oriented communications.

Investigating the impact of physical fatigue on construction workers’ situational awareness

Construction is a physically demanding occupation that requires workers to exert themselves when executing tasks. Many construction tasks involve manual handling, making fatigue part of construction workers’ everyday experience. Physical fatigue has been shown to impact worker safety as it affects workers’ cognitive ability to process hazard information. Studies have shown that when workers’ situational awareness diminishes, there is a higher tendency for workplace accidents. However, most studies measured physical fatigue using subjective scales which could be impacted by cognitive bias and a lack of quantitative values for measuring situational awareness. Thus, this study tracked individuals’ physical fatigue in real-time using a wearable sensor and assessed fatigue impact on participants’ Hazard Recognition Performance (HRP) and Safety Risk Assessment (SRA). Seventeen participants were recruited for this study and a validated instrument was used to assess their HRP and SRA. The wearable sensor showed that the participants experienced moderate-to-high intensity physical fatigue which was validated by a significant change in their heart rate (HR) and heart rate variability (HRV). The findings indicate that fatigue caused a significant reduction in the participants’ HRP (>12 % reduction) and SRA (>28 % reduction). Based on the results, the participants’ situational awareness had reduced significantly when their HR, HRV, and/or Rating of Fatigue (ROF) were correspondingly 135.20 bpm, 35.8 msec, and/or 9, while HR and ROF independently explained about 32 % of the variability of the HRP. This study empirically confirms the critical role of fatigue in situational awareness research and shows that wearable sensors could play a vital role in fatigue and hazard recognition assessment.

Travel Across More Time Zones Results in Worse Perceived Fatigue and Sleep in National-Team Footballers

This study investigated the association between (1)time zone difference and (2)travel direction (east vs west) with posttravel changes in perceptual responses of national-team footballers. Travel schedules from 355 national-team trips (50 elite soccer players) were verified using an online flight database. All players provided perceptual ratings of fatigue, sleep quality, soreness, and stress to calculate changes in scores up to 2days after travel. Trips were categorized as <3, 3 to 6, 6 to 9, or 9+ time zone changes, along with travel direction (eastward or westward). The pretravel to posttravel changes in perceptual ratings at days 1 and 2 postarrival were compared between time zone change and travel direction with linear mixed models. For every time zone crossed, poorer ratings of perceptual fatigue (β = 0.068, P < .001), sleep (β = 0.095, P < .001), soreness (β = 0.0049, P < .001), and total wellness (β = 0.214, P < .001) were observed. However, the models explained only small proportions of the variation in postflight perceptual responses (7%-18%). Regardless, travel across 9+ time zones resulted in significantly worse perceived fatigue, sleep, and total wellness for days 1 and 2 postarrival compared with travel with <6 time zones (P < .05). Additionally, fatigue, sleep, and total scores were worse on day 2 following trips of 9+ time zones. Eastward travel resulted in poorer sleep ratings (β = 0.52, P < .001) than westward travel within time zone groupings. Perceptual ratings of fatigue and sleep become progressively worse as travel increases in national-team soccer players, especially after travel across 9+ time zones and eastward travel.

Dissociations between coaches’ fatigue rating, athletes’ perceived fatigue, and objective training load

Players’ fatigue after practice is an important indicator of the actual training status for the coach. However, fatigue is not a unitary construct; it has objective (physiological) and perceived (experiential) aspects, which are not necessarily strongly related. The present study aimed to assess the association between coaches’ and athletes’ perception of fatigue and objectively assessed training load (TL). Participants were 61 elite players of five sport teams of two sports (basketball and football) and their coaches. Players’ and coaches’ perception of fatigue and objective data on TL provided by the Polar Team Pro system was obtained for 276 practice sessions overall. The association between coaches’ and athletes’ fatigue rating was .43 ( p &lt; .001), between coaches’ fatigue rating and TL was .5 ( p &lt; .001), and between athletes’ fatigue rating and TL was .45 ( p &lt; .001). Linear regression with TL as the criterion variable and coaches’ and athletes’ fatigue rating as predictor variables explained 32.8% of the total variance. As the discordance between coaches’ estimation of fatigue, athletes’ perceived fatigue, and objective TL appears substantial, coaches should always take into consideration the latter two indicators. Future research with a translational focus is needed to help coaches to find an optimal balance among various indicators of fatigue in the determination of the load for the subsequent training sessions.

Perceptions of fatigue and neuromuscular measures of performance fatigability during prolonged low-intensity elbow flexions.

What is the central question of this study? What is the predictive relationship between self-reported scales to quantify perceptions of fatigue during exercise and gold standard measures used to quantify the development of neuromuscular fatigue? What is the main finding and its importance? No scale was determined to be substantively more effective than another. However, the number of ongoing contractions performed was shown to be a better predictor of fatigue in the motor system than any of the subjective scales. The purpose of this study was to determine the relationship between transcranial magnetic stimulation (TMS) measures of performance fatigability and commonly used scales that quantify perceptions of fatigue during exercise. Twenty healthy participants (age 23±3years, 10 female) performed 10 submaximal isometric elbow flexions at 20% maximal voluntary contraction (MVC) for 2min, separated by 45s of rest. Biceps brachii muscle electromyography and elbow flexion torque responses to single-pulse TMS were obtained at the end of each contraction to assess central factors of performance fatigability. A rating of perceived exertion (RPE) scale, Omnibus Resistance scale, Likert scale, Rating of Fatigue scale and a visual analogue scale (VAS) were used to assess perceptions of fatigue at the end of each contraction. The RPE (root mean square error (RMSE)=0.144) and Rating of Fatigue (RMSE=0.145) scales were the best predictors of decline in MVC torque, whereas the Likert (RMSE=0.266) and RPE (RMSE=0.268) scales were the best predictors of electromyographic amplitude. Although the Likert (RMSE=7.6) and Rating of Fatigue (RMSE=7.6) scales were the best predictors of voluntary muscle activation of any scale, the number of contractions performed during the protocol was a better predictor (RMSE=7.3). The ability of the scales to predict TMS measures of performance fatigability were in general similar. Interestingly, the number of contractions performed was a better predictor of TMS measures than the scales themselves.