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Nino V, Monfort SM, Claudio D. Exploring the influence of individual factors on the perception of mental workload and body postures. ERGONOMICS 2024; 67:881-896. [PMID: 37545434 DOI: 10.1080/00140139.2023.2243406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/19/2023] [Indexed: 08/08/2023]
Abstract
Studies have revealed that physical and mental demands, psychosocial factors, and individual factors can contribute to the development of WMSDs. Yet, much is still unknown regarding the effects of individual characteristics on WMSDs susceptibility. Previous studies discovered people assumed more awkward body postures to perform an activity when the perception of mental workload is higher. This research study explored if individual characteristics such as age, sex, personality, and anxiety help explain changes or differences in the perception of mental workload and body postures assume when performing activities. The study provided evidence that these individual characteristics have a modifying role on perceived mental workload and body postures. The results suggest that perceived mental workload is influenced to a higher extent by individual characteristics such as anxiety, sex, and personality traits. Women have a higher (18.7%) mental workload perception than men. Likewise, NASA-TLX scores are 22% higher for feelers than thinkers. In general, higher perceptions of mental workload were observed in participants with higher anxiety levels. On the other hand, body postures seem to be influenced by different individual factors depending on the nature of the activity. RULA scores increased on average by 13.1% between baseline and time constraint conditions. Larger differences were observed in certain individuals (e.g. introverts (19.7%) and intuitors (13.8%)) across conditions.
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Affiliation(s)
- Valentina Nino
- Department of Industrial and Systems Engineering, Kennesaw State University, Marietta, GA, USA
| | - Scott M Monfort
- Department of Mechanical & Industrial Engineering, Montana State University, Bozeman, MT, USA
| | - David Claudio
- Department of Mechanical Engineering, University of Massachusetts Lowell, Lowell, MA, USA
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Wagenblast F, Läubli T, Seibt R, Rieger MA, Steinhilber B. Wrist Extensor Muscle Fatigue During a Dual Task With Two Muscular and Cognitive Load Levels in Younger and Older Adults. HUMAN FACTORS 2023:187208231218196. [PMID: 38058009 DOI: 10.1177/00187208231218196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
OBJECTIVE To examine the effect of concurrent physical and cognitive demands as well as age on indicators of muscle fatigue at the wrist. BACKGROUND There are few studies examining risk indicators for musculoskeletal disorders associated with work-related physical and cognitive demands that often occur simultaneously in the workplace. METHODS Twenty-four gender-balanced older and 24 gender-balanced younger (mean age 60 and 23 years) participants performed four 30 min dual tasks. Tasks differed by the muscular load level during force tracking: 5% and 10% of maximum voluntary contraction force (MVC) and concurrent cognitive demands on the working memory: easy and difficult. Muscle fatigue was assessed by MVC decline and changes in surface electromyography (increased root mean square: RMS, decreased median frequency: MF) at the extensor digitorum (ED) and extensor carpi ulnaris (EU). RESULTS A decline in MVC was found in all participants when tracking was performed at 10% MVC (mean ± SD: 137.9 ± 49.2 - 123.0 ± 45.3 N). Irrespective of age, muscular, or cognitive load, RMS increased (ED 12.3 ± 6.5 - 14.1 ± 7.0% MVE, EU 15.4 ± 7.6 - 16.9 ± 8.6% MVE) and MF decreased (ED 85.4 ± 13.6 - 83.2 ± 12.8 Hz, EU 107.2 ± 17.1 - 104.3 ± 16.7 Hz) in both muscles. However, changes in MF of EU tended to be more pronounced in the older group at higher cognitive and lower muscular load, without reaching statistical significance. CONCLUSION Maximum voluntary contraction indicated no interaction between muscle fatigue, cognitive load, or age. However, the tendencies toward altered muscle activity due to an increase in cognitive load and older age suggest muscular adaptations while maintaining tracking performance during the onset of fatigue signs in the sEMG signal. APPLICATION If the tendencies in muscle activity are confirmed by further studies, ergonomic assessments in industrial workplaces should consider cognitive load and age when describing the risk of musculoskeletal disorders.
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Affiliation(s)
- Florestan Wagenblast
- Institute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, Germany
| | - Thomas Läubli
- Institute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, Germany
| | - Robert Seibt
- Institute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, Germany
| | - Monika A Rieger
- Institute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, Germany
| | - Benjamin Steinhilber
- Institute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, Germany
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Yung M, Rose LM, Neumann WP, Yazdani A, Kapellusch J. Is there a u-shaped relationship between load levels and fatigue and recovery? An examination of possible mechanisms. ERGONOMICS 2023; 66:2058-2073. [PMID: 36846950 DOI: 10.1080/00140139.2023.2183850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/18/2023] [Indexed: 06/18/2023]
Abstract
In a previous study, an unexpected u-shaped relationship was observed between load level and fatigue/recovery responses. Moderate load levels resulted in lower perceived discomfort, pain, and fatigue, and shorter recovery times compared to either low or high load levels. This phenomenon has been reported in other studies, but no article has examined the possible mechanisms that might explain this u-shaped relationship. In this paper, we re-examined the previously published data and found that the phenomenon does not appear to be due to the experimental artefact; the u-shape may be due to unexpectedly lower fatigue effects at moderate loads, and higher fatigue effects at lower loads. We then conducted a literature review and identified several possible physiological, perceptual, and biomechanical explanatory mechanisms. No single mechanism explains the entirety of the phenomenon. Further research is needed on the relationship between work exposures, fatigue, and recovery, and the mechanisms related to the u-shaped relationship.Practitioner summary: We examine a previously observed u-shaped relationship between load level and fatigue/recovery, where moderate force resulted in lower perceived fatigue and shorter recovery times. A u-shaped fatigue response suggests that simply minimising load levels might not be an optimal approach to reduce the risk of workplace injuries.
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Affiliation(s)
- Marcus Yung
- Canadian Institute for Safety, Wellness, & Performance, Conestoga College Institute of Technology and Advanced Learning, Kitchener, Canada
| | - Linda M Rose
- Division of Ergonomics, Department of Biomedical Engineering and Health Systems, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Huddinge, Sweden
| | - W Patrick Neumann
- Department of Mechanical and Industrial Engineering, Faculty of Engineering and Architectural Science, Toronto Metropolitan University, Toronto, Canada
| | - Amin Yazdani
- Canadian Institute for Safety, Wellness, & Performance, Conestoga College Institute of Technology and Advanced Learning, Kitchener, Canada
| | - Jay Kapellusch
- Department of Rehabilitation Sciences & Technology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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Mixter S, Mathiassen SE, Jahncke H, Hygge S, Lyskov E, Hallman DM, Lewis C. Effects of Combining Occupationally Relevant Physical and Cognitive Tasks. A Systematic Review. Ann Work Expo Health 2023; 67:303-319. [PMID: 36469430 PMCID: PMC10015802 DOI: 10.1093/annweh/wxac082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 10/24/2022] [Accepted: 11/03/2022] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES Physical and cognitive tasks occur together in many occupations. Previous reviews of combined tasks have mainly focused on their effects in a sports context. This review investigated to which extent combinations (concurrent or alternating) of occupationally relevant physical and cognitive tasks influence responses reflecting biomechanical exposure, stress, fatigue, performance, and well-being. METHODS We searched Scopus, Pubmed, Cinahl, and Psychinfo for controlled experiments investigating the effects of combinations of occupationally relevant physical and cognitive tasks in participants aged 18 to 70. In total, we identified 12 447 records. We added recent papers that had cited these studies (n = 573) to arrive at a total of 13 020 publications. After screening for relevance, 61 studies remained, of which 57 were classified to be of medium or high quality. Of the 57 studies, 51 addressed concurrent tasks, 5 alternating tasks, and 1 both concurrent and alternating tasks. RESULTS Most studies of concurrent physical and cognitive tasks reported negative effects, if numerically small, on indicators of biomechanical exposure, fatigue, and performance, compared to a physical task alone. Results were mixed for stress indicators, and well-being was too little studied to justify any conclusions. Effects depended on the tasks, including their intensity and complexity. Alternating physical and cognitive tasks did not appear to influence outcomes much, compared to having passive breaks in-between physical tasks. CONCLUSIONS The reviewed evidence indicated that concurrent physical and cognitive work tasks have negative, yet small effects on biomechanical indicators, fatigue and performance, compared to performing the physical task alone, but only if the physical task is intense, and the cognitive task is complex. Alternating between physical and cognitive tasks may have similar effects as breaking up physical tasks by passive breaks, but studies were few. Future studies should address ecologically valid combinations of physical and cognitive tasks, in particular in controlled field studies devoted to the long-term effects of combined work.
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Affiliation(s)
- Susanna Mixter
- Centre for Musculoskeletal Research, Department of Occupational Health Sciences and Psychology, University of Gävle, 801 76 Gävle, Sweden
| | - Svend Erik Mathiassen
- Centre for Musculoskeletal Research, Department of Occupational Health Sciences and Psychology, University of Gävle, 801 76 Gävle, Sweden
| | - Helena Jahncke
- Centre for Musculoskeletal Research, Department of Occupational Health Sciences and Psychology, University of Gävle, 801 76 Gävle, Sweden
| | - Staffan Hygge
- Department of Building, Energy, and Environmental Engineering, University of Gävle, 801 76 Gävle, Sweden
| | - Eugene Lyskov
- Centre for Musculoskeletal Research, Department of Occupational Health Sciences and Psychology, University of Gävle, 801 76 Gävle, Sweden
| | - David M Hallman
- Centre for Musculoskeletal Research, Department of Occupational Health Sciences and Psychology, University of Gävle, 801 76 Gävle, Sweden
| | - Charlotte Lewis
- Department of Public Health and Clinical Medicine, Umeå University, 901 85 Umeå, Sweden
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Vymyslický P, Pavlů D, Pánek D. Effect of Mental Task on Sex Differences in Muscle Fatigability: A Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:13621. [PMID: 36294199 PMCID: PMC9603675 DOI: 10.3390/ijerph192013621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/17/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Previous research demonstrated that there are observable sex differences in developing muscle fatigue when mental task during fatiguing activity is present; however, there is no available review on this matter. Therefore, this review aimed to summarize the findings of previous studies investigating the effect of mental task on muscle fatigue in men and women. To conduct the review, we utilized searches using the electronic databases Web of Science, PubMed, Scopus, and EBSCO Cinahl Ultimate. The studies included had no limited publication date and examined the effects of mental task on muscle fatigue in a healthy adult population of any age. The evaluation was performed using the following criteria: time to failure, or subjective scale in various modifications (visual analog scale-VAS, rate of perceived effort-RPE, rate of perceived fatigue-RPF, rate of perceived discomfort-RPD). A total of seven studies met the set criteria, which were subsequently analyzed. Heavy mental task (more demanding math tasks) can reduce the time to failure for both men and women, with the reduction being more pronounced for women than for men. For light mental task (simple math tasks), no reduction in time to failure was observed to a great extent. The mental task in any of the included studies did not affect the subjective perception of fatigue, effort, discomfort, or pain. Although the studies investigating the effect of mental task on sex differences in muscle fatigability are limited, based on our findings we can assume that in jobs requiring heavier mental task, women may be more prone to the faster development of muscle fatigue; thus, employers might consider paying attention to the possibility of adequate rest.
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Gerstner GR, Mota JA, Giuliani HK, Weaver MA, Shea NW, Ryan ED. The impact of repeated bouts of shiftwork on rapid strength and reaction time in career firefighters. ERGONOMICS 2022; 65:1086-1094. [PMID: 34882513 DOI: 10.1080/00140139.2021.2016997] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 09/17/2021] [Indexed: 06/13/2023]
Abstract
The purpose of this study was to examine the influence of repeated bouts of shiftwork on lower extremity maximal and rapid strength and reaction time in career firefighters. Thirty-five firefighters (3 females; 34.3 ± 9.1 years) performed a psychomotor vigilance test (PVT) and reactive maximal isometric strength assessment prior to and following a full shift rotation (three 24-hr on-off shifts). Reaction time (RT), maximal, absolute and normalised rapid strength (50, 100, 150, 200 ms), and PVT measures were assessed on-site. Separate linear regression models were used to evaluate the POST-PRE change in variables adjusted for BMI, age, sleep, and call duration. Early (50 ms) absolute rapid strength was the only variable significantly reduced (-25.9%; p = 0.031) following the full shift rotation. Our findings indicate that early rapid strength may be a sensitive measure in detecting work-related fatigue, despite minimal changes in sleep between work and non-work nights and a low call duration. Practitioner summary: We examined the impact of repeated shiftwork on changes in reaction time and neuromuscular function. Early rapid strength was a sensitive, portable lab assessment that feasibly measured work-related fatigue in career firefighters. Interventions that mitigate work-related fatigue may be impactful at preventing falls and/or risk of musculoskeletal injury.
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Affiliation(s)
- Gena R Gerstner
- Neuromechanics Laboratory, Department of Human Movement Sciences, Old Dominion University, Norfolk, VA, USA
| | - Jacob A Mota
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA
| | - Hayden K Giuliani
- Neuromuscular Assessment Laboratory, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark A Weaver
- Department of Mathematics and Statistics, Elon University, Elon, NC, USA
| | | | - Eric D Ryan
- Neuromuscular Assessment Laboratory, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Allied Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Health-related consequences of the type and utilization rates of electronic devices by college students. BMC Public Health 2021; 21:1970. [PMID: 34724921 PMCID: PMC8559143 DOI: 10.1186/s12889-021-11975-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 10/06/2021] [Indexed: 11/10/2022] Open
Abstract
Background College students are leading an evolution of device use both in the type of device and the frequency of use. They have transitioned from desktop stations to laptops, tablets, and especially smartphones and use them throughout the day and into the night. Methods Using a 35-min online survey, we sought to understand how technology daily usage patterns, device types, and postures affect pain and discomfort to understand how knowledge of that pain might help students avoid it. Data were analyzed from 515 students (69.5% male) who completed an internet-delivered survey (81.3% response rate). Results Participants ranked smartphones as their most frequently used technology (64.0%), followed by laptops and tablets (both 53.2%), and desktop computers (46.4%). Time spent using smartphones averaged over 4.4 h per day. When using their devices, students were more likely to adopt non-traditional workplace postures as they used these devices primarily on the couch or at a chair with no desk. Conclusion Recent trends in wireless academic access points along with the portability of small handheld devices, have made smartphones the most common link to educational materials despite having the least favorable control and display scenario from an ergonomic perspective. Further, the potential impact of transitions in work environments due to COVID-19 may further exacerbate ergonomic issues among millions highlighting the need for such work to be carried out.
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Stress-Related Responses to Alternations between Repetitive Physical Work and Cognitive Tasks of Different Difficulties. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17228509. [PMID: 33212862 PMCID: PMC7698406 DOI: 10.3390/ijerph17228509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/30/2020] [Accepted: 11/13/2020] [Indexed: 01/20/2023]
Abstract
Alternating between physical and cognitive tasks has been proposed as an alternative in job rotation, allowing workers to recover from the physical work while still being productive. However, effects of such alternations on stress have not been investigated. This controlled experiment aimed at determining the extent to which stress-related responses develop during alternating physical and cognitive work, and to determine the extent to which cognitive task (CT) difficulty influences these responses. Fifteen women performed three sessions of 10 consecutive work bouts each including a seven-minute repetitive physical task (pipetting) and a three-minute CT (n-back) at one of three difficulty levels. Stress was assessed in terms of changes in heart rate variability, blood pressure, salivary alpha-amylase, salivary cortisol, perceived stress, and cognitive performance. The work session did not result in any marked stress response, and CT difficulty did not significantly influence stress, apart from alpha-amylase being higher at the easiest CT (F = 5.34, p = 0.02). Thus, according to our results, alternating between repetitive physical tasks and cognitive tasks may be a feasible alternative to classic job rotation between physical tasks only, even if the cognitive task is quite difficult. Future studies should address possible effects of the temporal pattern of alternations, and combine even other occupationally relevant tasks, preferably for extended periods of time.
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Duckworth SC, Higginbotham CS, Pederson JA, Rogers RR, Marshall MR, Williams TD, Ballmann CG. Physical and Cognitive Performance During Upper-Extremity Versus Full-Body Exercise Under Dual Tasking Conditions. Percept Mot Skills 2020; 128:338-352. [PMID: 32741251 DOI: 10.1177/0031512520945088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The purpose of this study was to investigate physical and cognitive performance during dual task conditions of upper-extremity (UE) or full-body (FB) rowing exercise. In a crossover counterbalanced design, college-aged male and female participants completed five conditions: (a) Sitting, (b) Single task UE rowing, (c) Single task FB rowing, (d) Dual task UE rowing, and (e) Dual task FB rowing. For single task UE and FB rowing conditions, participants were asked to row as hard as possible. After sitting and dual-task conditions, we administered the Paced Auditory Serial Addition Test (PASAT) and a word-list memory test. We analyzed participants' absolute differences (single task - dual task) in power output and their cognitive test scores to compare UE and FB rowing. There were no significant absolute differences from sitting to dual task conditions of UE and FB rowing for either PASAT (p = 0.958) or word list memory (p = 0.899) cognitive scores. Absolute power output loss from single to dual task conditions was significantly higher in FB versus UE for PASAT (p = 0.039; d = 0.54) and word list memory (p = 0.021; d = 0.66) in the dual task condition. These results suggest that, while cognitive performance was preserved regardless of the amount of muscle mass activated during dual task rowing, physical performance suffered more during FB than UE rowing under the dual task condition. These findings have important implications for optimizing cognitive and physical performance in dual task situations.
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Affiliation(s)
- Sarah C Duckworth
- Department of Kinesiology, 1744Samford University, Birmingham, Alabama, United States
| | - Carrie S Higginbotham
- Department of Kinesiology, 1744Samford University, Birmingham, Alabama, United States
| | - Joseph A Pederson
- Department of Kinesiology, 1744Samford University, Birmingham, Alabama, United States
| | - Rebecca R Rogers
- Department of Kinesiology, 1744Samford University, Birmingham, Alabama, United States
| | - Mallory R Marshall
- Department of Kinesiology, 1744Samford University, Birmingham, Alabama, United States
| | - Tyler D Williams
- Department of Kinesiology, 1744Samford University, Birmingham, Alabama, United States
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Zhu Y, Rodriguez-Paras C, Rhee J, Mehta RK. Methodological Approaches and Recommendations for Functional Near-Infrared Spectroscopy Applications in HF/E Research. HUMAN FACTORS 2020; 62:613-642. [PMID: 31107601 DOI: 10.1177/0018720819845275] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
OBJECTIVE The objective of this study was to systematically document current methods and protocols employed when using functional near-infrared spectroscopy (fNIRS) techniques in human factors and ergonomics (HF/E) research and generate recommendations for conducting and reporting fNIRS findings in HF/E applications. METHOD A total of 1,687 articles were identified through Ovid-MEDLINE, PubMed, Web of Science, and Scopus databases, of which 37 articles were included in the review based on review inclusion/exclusion criteria. RESULTS A majority of the HF/E fNIRS investigations were found in transportation, both ground and aviation, and in assessing cognitive (e.g., workload, working memory) over physical constructs. There were large variations pertaining to data cleaning, processing, and analysis approaches across the studies that warrant standardization of methodological approaches. The review identified major challenges in transparency and reporting of important fNIRS data collection and analyses specifications that diminishes study replicability, introduces potential biases, and increases likelihood of inaccurate results. As such, results reported in existing fNIRS studies need to be cautiously approached. CONCLUSION To improve the quality of fNIRS investigations and/or to facilitate its adoption and integration in different HF/E applications, such as occupational ergonomics and rehabilitation, recommendations for fNIRS data collection, processing, analysis, and reporting are provided.
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Affiliation(s)
- Yibo Zhu
- 14736 Texas A&M University, College Station, USA
| | | | - Joohyun Rhee
- 14736 Texas A&M University, College Station, USA
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Choi J, Yeoh WL, Loh PY, Muraki S. Force and electromyography responses during isometric force release of different rates and step-down magnitudes. Hum Mov Sci 2019; 67:102516. [PMID: 31539754 DOI: 10.1016/j.humov.2019.102516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/27/2019] [Accepted: 09/04/2019] [Indexed: 11/26/2022]
Abstract
This study investigated motor responses of force release during isometric elbow flexion by comparing effects of different ramp durations and step-down magnitudes. Twelve right-handed participants (age: 23.1 ± 1.1) performed trajectory tracking tasks. Participants were instructed to release their force from the reference magnitude (REF; 40% of maximal voluntary contraction force) to a step-down magnitude of 67% REF or 33% REF and maintain the released magnitude. Force release was guided by ramp durations of either 1 s or 5 s. Electromyography of the biceps brachii and triceps brachii was performed during the experimental task, and the co-contraction ratio was evaluated. Force output was recorded to evaluate the parameters of motor performance, such as force variability and overshoot ratio. Although a longer ramp duration of 5 s decreased the force variability and overshoot ratio than did shorter ramp duration of 1 s, higher perceived exertion and co-contraction ratio were followed. Force variability was greater when force was released to the step-down magnitude of 33% REF than that when the magnitude was 67% REF, however, the overshoot ratio showed opposite results. This study provided evidence proving that motor control strategies adopted for force release were affected by both duration and step-down magnitude. In particular, it implies that different control strategies are required according to the level of step-down magnitude with a relatively short ramp duration.
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Affiliation(s)
- Jeewon Choi
- Department of Human Science, Graduate School of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, Fukuoka 815-8540, Japan.
| | - Wen Liang Yeoh
- Department of Human Science, Graduate School of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, Fukuoka 815-8540, Japan
| | - Ping Yeap Loh
- Department of Human Science, Faculty of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, Fukuoka 815-8540, Japan
| | - Satoshi Muraki
- Department of Human Science, Faculty of Design, Kyushu University, 4-9-1 Shiobaru, Minami-ku, Fukuoka 815-8540, Japan
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Mantooth WP, Mehta RK, Rhee J, Cavuoto LA. Task and sex differences in muscle oxygenation during handgrip fatigue development. ERGONOMICS 2018; 61:1646-1656. [PMID: 30317942 DOI: 10.1080/00140139.2018.1504991] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/10/2018] [Accepted: 07/18/2018] [Indexed: 06/08/2023]
Abstract
The purpose of this study was to examine task and sex differences in forearm muscle oxygenation, measured using near infrared spectroscopy, during sustained submaximal handgrip exercises. Forty-eight adults (50% males) performed fatiguing handgrip exercises at 20, 40, 60 and 80% of their maximum handgrip strength. While males and females exhibited similar levels of relative fatigability, forearm oxygenation was found to be task (i.e. contraction intensity and phase of fatigue development) and sex dependent. Higher contraction intensities were associated with greater desaturation over time. Compared to females, males exhibited greater desaturation as fatigue progressed and this was augmented at higher contraction intensities. These may be likely affected by sex differences in muscle mass, morphology and strength differences during exercises at relative intensities. Future work that explores sex differences in muscle oxygenation during absolute force intensities are needed, which may have implications for muscle fatigue development and potential fatigue mitigation strategies. Practitioner Summary: Muscle oxygenation impacts fatigue development that can in turn affect worker health and productivity. Males exhibit greater forearm desaturation than females at higher relative work intensities, despite similar fatigue levels. Females may be predisposed to greater muscle delivery and oxygenation challenges that can increase their fatigability during work at absolute load levels.
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Affiliation(s)
- Whitney P Mantooth
- a Environmental and Occupational Health , Texas A&M University, College Station , TX , USA
| | - Ranjana K Mehta
- a Environmental and Occupational Health , Texas A&M University, College Station , TX , USA
- b Industrial and Systems Engineering , Texas A&M University, College Station , TX , USA
| | - Joohyun Rhee
- a Environmental and Occupational Health , Texas A&M University, College Station , TX , USA
| | - Lora A Cavuoto
- c Industrial and Systems Engineering , University at Buffalo , Buffalo , NY , USA
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13
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Zhang JY, Liu SL, Feng QM, Gao JQ, Zhang Q. Correlative Evaluation of Mental and Physical Workload of Laparoscopic Surgeons Based on Surface Electromyography and Eye-tracking Signals. Sci Rep 2017; 7:11095. [PMID: 28894216 PMCID: PMC5594030 DOI: 10.1038/s41598-017-11584-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 08/25/2017] [Indexed: 11/21/2022] Open
Abstract
Surgeons’ mental and physical workloads are major focuses of operating room (OR) ergonomics, and studies on this topic have generally focused on either mental workload or physical workload, ignoring the interaction between them. Previous studies have shown that physically demanding work may affect mental performance and may be accompanied by impaired mental processing and decreased performance. In this study, 14 participants were recruited to perform laparoscopic cholecystectomy (LC) procedures in a virtual simulator. Surface electromyography (sEMG) signals of the bilateral trapezius, bicipital, brachioradialis and flexor carpi ulnaris (FCU) muscles and eye-tracking signals were acquired during the experiment. The results showed that the least square means of muscle activity during the LC phases of surgery in an all-participants mixed effects model were 0.79, 0.81, and 0.98, respectively. The observed muscle activities in the different phases exhibited some similarity, while marked differences were found between the forearm bilateral muscles. Regarding mental workload, significant differences were observed in pupil dilation between the three phases of laparoscopic surgery. The mental and physical workloads of laparoscopic surgeons do not appear to be generally correlated, although a few significant negative correlations were found. This result further indicates that mental fatigue does markedly interfere with surgeons’ operating movements.
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Affiliation(s)
- Jian-Yang Zhang
- Department of Medical Engineering, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,School of Computer and Information Technology, Nanyang Normal University, Nanyang, Henan, P.R. China.,Healthcare Ergonomics Lab, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Sheng-Lin Liu
- Department of Medical Engineering, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,Healthcare Ergonomics Lab, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Qing-Min Feng
- Department of Medical Engineering, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,Healthcare Ergonomics Lab, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jia-Qi Gao
- Department of Medical Engineering, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,Healthcare Ergonomics Lab, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Qiang Zhang
- Department of Medical Engineering, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China. .,Healthcare Ergonomics Lab, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Age-specific neural strategies to maintain motor performance after an acute social stress bout. Exp Brain Res 2017; 235:2049-2057. [PMID: 28357463 DOI: 10.1007/s00221-017-4949-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 03/24/2017] [Indexed: 12/17/2022]
Abstract
Stress due to cognitive demands and fatigue have shown to impair motor performance in older adults; however, the effect of social stress and its influence on prefrontal cortex (PFC) functioning in older adults during upper extremity motor performance tasks is not known. The present study explored the after-effects of an acute social stress bout on neural strategies, measured using PFC and hand/arm muscle activation, and adopted by younger and older adults to maintain handgrip force control. Nine older [74.1 (6.5) years; three men, six women] and ten younger [24.2 (5.0) years, four men, six women] adults performed handgrip force control trials at 30% maximum voluntary contractions before and after the Trier Social Stress Test (TSST). PFC activity was measured using functional near infrared spectroscopy and muscle activity from the flexor and extensor carpi radialis (FCR/ECR) was measured using electromyography. In general, aging was associated with decreased force steadiness and force complexity with a concomitant increase in bilateral PFC activity. While motor performance remained comparable before and after the TSST stress session in both age groups, the associated neural strategies differed between groups. While the stress condition was associated with lower FCR and ECR activity in younger adults despite no change in the PFC activation, stress was associated with increases in FCR activity in older adults. This stress-related compensatory neural strategy of increasing hand/arm muscle activation, potentially via the additional recruitment of the stress-motor neural circuitry, may have played a role in maintaining motor performance in older adults.
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15
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Shortz AE, Mehta RK. Cognitive challenges, aging, and neuromuscular fatigue. Physiol Behav 2017; 170:19-26. [DOI: 10.1016/j.physbeh.2016.11.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/10/2016] [Accepted: 11/24/2016] [Indexed: 11/29/2022]
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16
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17
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Petersen SR, Anderson GS, Tipton MJ, Docherty D, Graham TE, Sharkey BJ, Taylor NA. Towards best practice in physical and physiological employment standards. Appl Physiol Nutr Metab 2016; 41:S47-62. [DOI: 10.1139/apnm-2016-0003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
While the scope of the term physical employment standards is wide, the principal focus of this paper is on standards related to physiological evaluation of readiness for work. Common applications of such employment standards for work are in public safety and emergency response occupations (e.g., police, firefighting, military), and there is an ever-present need to maximize the scientific quality of this research. Historically, most of these occupations are male-dominated, which leads to potential sex bias during physical demands analysis and determining performance thresholds. It is often assumed that older workers advance to positions with lower physical demand. However, this is not always true, which raises concerns about the long-term maintenance of physiological readiness. Traditionally, little attention has been paid to the inevitable margin of uncertainty that exists around cut-scores. Establishing confidence intervals around the cut-score can reduce for this uncertainty. It may also be necessary to consider the effects of practise and biological variability on test scores. Most tests of readiness for work are conducted under near perfect conditions, while many emergency responses take place under far more demanding and unpredictable conditions. The potential impact of protective clothing, respiratory protection, load carriage, environmental conditions, nutrition, fatigue, sensory deprivation, and stress should also be considered when evaluating readiness for work. In this paper, we seek to establish uniformity in terminology in this field, identify key areas of concern, provide recommendations to improve both scientific and professional practice, and identify priorities for future research.
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Affiliation(s)
- Stewart R. Petersen
- Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB T6G 2H9, Canada
| | | | - Michael J. Tipton
- Department of Sport and Exercise Sciences, University of Portsmouth, Portsmouth, Hants, PO1 2ER, UK
| | - David Docherty
- School of Exercise Science, Physical & Health Education, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Terry E. Graham
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Brian J. Sharkey
- Department of Health and Human Performance, University of Montana, Missoula, MT 59812, USA
| | - Nigel A.S. Taylor
- Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia
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18
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Shortz AE, Pickens A, Zheng Q, Mehta RK. The effect of cognitive fatigue on prefrontal cortex correlates of neuromuscular fatigue in older women. J Neuroeng Rehabil 2015; 12:115. [PMID: 26689713 PMCID: PMC4687384 DOI: 10.1186/s12984-015-0108-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/15/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND As the population of adults aged 65 and above is rapidly growing, it is crucial to identify physical and cognitive limitations pertaining to daily living. Cognitive fatigue has shown to adversely impact neuromuscular function in younger adults, however its impact on neuromuscular fatigue, and associated brain function changes, in older adults is not well understood. The aim of the study was to examine the impact of cognitive fatigue on neuromuscular fatigue and associated prefrontal cortex (PFC) activation patterns in older women. METHODS Eleven older (75.82 (7.4) years) females attended two sessions and performed intermittent handgrip exercises at 30 % maximum voluntary contraction (MVC) until voluntary exhaustion after a 60-min control (watching documentary) and 60-min cognitive fatigue (performing Stroop Color Word and 1-Back tests) condition. Dependent measures included endurance time, strength loss, PFC activity (measured using fNIRS), force fluctuations, muscle activity, cardiovascular responses, and perceived discomfort. RESULTS Participants perceived greater cognitive fatigue after the 60-min cognitive fatigue condition when compared to the control condition. While neuromuscular fatigue outcomes (i.e., endurance time, strength loss, perceived discomfort), force fluctuations, and muscle activity were similar across both the control and cognitive fatigue conditions, greater decrements in PFC activity during neuromuscular fatigue development after the cognitive fatigue condition were observed when compared to the control condition. CONCLUSION Despite similar neuromuscular outcomes, cognitive fatigue was associated with blunted PFC activation during the handgrip fatiguing exercise that may be indicative of neural adaptation with aging in an effort to maintain motor performance. Examining the relationship between cognitive fatigue and neuromuscular output by imaging other motor-related brain regions are needed to provide a better understanding of age-related compensatory adaptations to perform daily tasks that involve some levels of cognitive demand and physical exercise, especially when older adults experience them sequentially.
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Affiliation(s)
- Ashley E Shortz
- Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX, 77843, USA.
| | - Adam Pickens
- Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX, 77843, USA.
| | - Qi Zheng
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, TX, 77843, USA.
| | - Ranjana K Mehta
- Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX, 77843, USA.
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19
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Mehta RK. Stunted PFC activity during neuromuscular control under stress with obesity. Eur J Appl Physiol 2015; 116:319-26. [DOI: 10.1007/s00421-015-3283-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/15/2015] [Indexed: 12/25/2022]
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20
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Srinivasan D, Mathiassen SE, Hallman DM, Samani A, Madeleine P, Lyskov E. Effects of concurrent physical and cognitive demands on muscle activity and heart rate variability in a repetitive upper-extremity precision task. Eur J Appl Physiol 2015; 116:227-39. [DOI: 10.1007/s00421-015-3268-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 09/15/2015] [Indexed: 11/30/2022]
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Mehta RK, Agnew MJ. Subjective evaluation of physical and mental workload interactions across different muscle groups. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12:62-68. [PMID: 25025738 DOI: 10.1080/15459624.2014.942455] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Both physical and mental demands, and their interactions, have been shown to increase biomechanical loading and physiological reactivity as well as impair task performance. Because these interactions have shown to be muscle-dependent, the aim of this study was to determine the sensitivity of the NASA Task Load Index (NASA TLX) and Ratings of Perceived Exertion (RPE) to evaluate physical and mental workload during muscle-specific tasks. Twenty-four participants performed upper extremity and low back exertions at three physical workload levels in the absence and presence of a mental stressor. Outcome measures included RPE and NASA TLX (six sub-scales) ratings. The findings indicate that while both RPEs and NASA TLX ratings were sensitive to muscle-specific changes in physical demand, only an additional mental stressor and its interaction with either physical demand or muscle groups influenced the effort sub-scale and overall workload scores of the NASA TLX. While additional investigations in actual work settings are warranted, the NASA TLX shows promise in evaluating perceived workload that is sensitive not only to physical and mental demands but also sensitive in determining workload for tasks that employ different muscle groups.
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Affiliation(s)
- Ranjana K Mehta
- a Department of Environmental and Occupational Health , Texas A&M University , College Station , Texas
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22
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Mathiassen SE, Hallman DM, Lyskov E, Hygge S. Can cognitive activities during breaks in repetitive manual work accelerate recovery from fatigue? A controlled experiment. PLoS One 2014; 9:e112090. [PMID: 25375644 PMCID: PMC4222971 DOI: 10.1371/journal.pone.0112090] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 10/13/2014] [Indexed: 11/18/2022] Open
Abstract
Neurophysiologic theory and some empirical evidence suggest that fatigue caused by physical work may be more effectively recovered during “diverting” periods of cognitive activity than during passive rest; a phenomenon of great interest in working life. We investigated the extent to which development and recovery of fatigue during repeated bouts of an occupationally relevant reaching task was influenced by the difficulty of a cognitive activity between these bouts. Eighteen male volunteers performed three experimental sessions, consisting of six 7-min bouts of reaching alternating with 3 minutes of a memory test differing in difficulty between sessions. Throughout each session, recordings were made of upper trapezius muscle activity using electromyography (EMG), heart rate and heart rate variability (HRV) using electrocardiography, arterial blood pressure, and perceived fatigue (Borg CR10 scale and SOFI). A test battery before, immediately after and 1 hour after the work period included measurements of maximal shoulder elevation strength (MVC), pressure pain threshold (PPT) over the trapezius muscles, and a submaximal isometric contraction. As expected, perceived fatigue and EMG amplitude increased during the physical work bouts. Recovery did occur between the bouts, but fatigue accumulated throughout the work period. Neither EMG changes nor recovery of perceived fatigue during breaks were influenced by cognitive task difficulty, while heart rate and HRV recovered the most during breaks with the most difficult task. Recovery of perceived fatigue after the 1 hour work period was also most pronounced for the most difficult cognitive condition, while MVC and PPT showed ambiguous patterns, and EMG recovered similarly after all three cognitive protocols. Thus, we could confirm that cognitive tasks between bouts of fatiguing physical work can, indeed, accelerate recovery of some factors associated with fatigue, even if benefits may be moderate and some responses may be equivocal. Our results encourage further research into combinations of physical and mental tasks in an occupational context.
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Affiliation(s)
- Svend Erik Mathiassen
- Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gävle, Gävle, Sweden
- * E-mail:
| | - David M. Hallman
- Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gävle, Gävle, Sweden
| | - Eugene Lyskov
- Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gävle, Gävle, Sweden
| | - Staffan Hygge
- Department of Building, Energy and Environmental Engineering, University of Gävle, Gävle, Sweden
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Impacts of obesity and stress on neuromuscular fatigue development and associated heart rate variability. Int J Obes (Lond) 2014; 39:208-13. [PMID: 25042859 DOI: 10.1038/ijo.2014.127] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/30/2014] [Accepted: 07/13/2014] [Indexed: 11/08/2022]
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Mehta RK, Parasuraman R. Effects of mental fatigue on the development of physical fatigue: a neuroergonomic approach. HUMAN FACTORS 2014; 56:645-656. [PMID: 25029891 DOI: 10.1177/0018720813507279] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVE The present study used a neuroergonomic approach to examine the interaction of mental and physical fatigue by assessing prefrontal cortex activation during submaximal fatiguing handgrip exercises. BACKGROUND Mental fatigue is known to influence muscle function and motor performance, but its contribution to the development of voluntary physical fatigue is not well understood. METHOD A total of 12 participants performed separate physical (control) and physical and mental fatigue (concurrent) conditions at 30% of their maximal handgrip strength until exhaustion. Functional near infrared spectroscopy was employed to measure prefrontal cortex activation, whereas electromyography and joint steadiness were used simultaneously to quantify muscular effort. RESULTS Compared to the control condition, blood oxygenation in the bilateral prefrontal cortex was significantly lower during submaximal fatiguing contractions associated with mental fatigue at exhaustion, despite comparable muscular responses. CONCLUSION The findings suggest that interference in the prefrontal cortex may influence motor output during tasks that require both physical and cognitive processing. APPLICATION A neuroergonomic approach involving simultaneous monitoring of brain and body functions can provide critical information on fatigue development that may be overlooked during traditional fatigue assessments.
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25
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Dual-task interference between climbing and a simulated communication task. Exp Brain Res 2014; 232:1367-77. [DOI: 10.1007/s00221-014-3855-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 01/24/2014] [Indexed: 11/26/2022]
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26
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Joseph C, Beach TAC, Callaghan JP, Dickerson CR. The influence of precision requirements and cognitive challenges on upper extremity joint reaction forces, moments and muscle force estimates during prolonged repetitive lifting. ERGONOMICS 2014; 57:236-246. [PMID: 24437984 DOI: 10.1080/00140139.2013.869359] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 11/09/2013] [Indexed: 06/03/2023]
Abstract
UNLABELLED Prolonged repetitive lifting is a whole-body exertion. Despite this, the roles and physical exposures of the upper extremities are frequently neglected. The influence of precision requirements and cognitive distractions on upper extremity responses when lifting was evaluated by quantifying several biomechanical upper extremity quantities. Nine participants completed four 30-min lifting tasks with and without simultaneous cognitive distractions and/or precision placement constraints. Specific metrics evaluated were joint reaction forces and moments (wrist, elbow and shoulder) and modelled shoulder muscle forces (38 defined shoulder muscle mechanical elements). The addition of a precision requirement increased several metrics by up to 43%, while the addition of the cognitive distraction task had minimal influence. Furthermore, several metrics decreased by up to 14% after the first 10 min of lifting, suggesting a temporal change of lifting strategy. PRACTITIONER SUMMARY Lifting tasks often include precision placements and cognitive demands. This study shows that precision placement during prolonged repetitive lifting increases upper extremity forces and moments, while the addition of a cognitive task is benign. Furthermore, field assessments of repetitive lifting should include observations longer than 10 min, as adaptive strategies appear to be adopted.
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Affiliation(s)
- Caroline Joseph
- a Department of Kinesiology, Faculty of Applied Health Science , University of Waterloo , Waterloo , ON , Canada
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Mehta RK, Parasuraman R. Neuroergonomics: a review of applications to physical and cognitive work. Front Hum Neurosci 2013; 7:889. [PMID: 24391575 PMCID: PMC3870317 DOI: 10.3389/fnhum.2013.00889] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 12/05/2013] [Indexed: 02/04/2023] Open
Abstract
Neuroergonomics is an emerging science that is defined as the study of the human brain in relation to performance at work and in everyday settings. This paper provides a critical review of the neuroergonomic approach to evaluating physical and cognitive work, particularly in mobile settings. Neuroergonomics research employing mobile and immobile brain imaging techniques are discussed in the following areas of physical and cognitive work: (1) physical work parameters; (2) physical fatigue; (3) vigilance and mental fatigue; (4) training and neuroadaptive systems; and (5) assessment of concurrent physical and cognitive work. Finally, the integration of brain and body measurements in investigating workload and fatigue, in the context of mobile brain/body imaging ("MoBI"), is discussed.
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Affiliation(s)
- Ranjana K Mehta
- Department of Environmental and Occupational Health, School of Rural Public Healthy, Texas A&M University, College Station TX, USA
| | - Raja Parasuraman
- Center of Excellence in Neuroergonomics, Technology, and Cognition, George Mason University Fairfax, VA, USA
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28
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Mehta RK, Shortz AE. Obesity-related differences in neural correlates of force control. Eur J Appl Physiol 2013; 114:197-204. [PMID: 24197082 DOI: 10.1007/s00421-013-2762-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/24/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND Greater body segment mass due to obesity has shown to impair gross and fine motor functions and reduce balance control. While recent studies suggest that obesity may be linked with altered brain functions involved in fine motor tasks, this association is not well investigated. OBJECTIVE The purpose of this study was to examine the neural correlates of motor performance in non-obese and obese adults during force control of two upper extremity muscles. METHODS Nine non-obese and eight obese young adults performed intermittent handgrip and elbow flexion exertions at 30% of their respective muscle strengths for 4 min. Functional near infrared spectroscopy was employed to measure neural activity in the prefrontal cortex bilaterally, joint steadiness was computed using force fluctuations, and ratings of perceived exertions (RPEs) were obtained to assess perceived effort. RESULTS Obesity was associated with higher force fluctuations and lower prefrontal cortex activation during handgrip exertions, while RPE scores remained similar across both groups. No obesity-related differences in neural activity, force fluctuation, or RPE scores were observed during elbow flexion exertions. CONCLUSION The study is one of the first to examine obesity-related differences on prefrontal cortex activation during force control of the upper extremity musculature. The study findings indicate that the neural correlates of motor activity in the obese may be muscle-specific. Future work is warranted to extend the investigation to monitoring multiple motor-function related cortical regions and examining obesity differences with different task parameters (e.g., longer duration, increased precision demands, larger muscles, etc.).
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Affiliation(s)
- Ranjana K Mehta
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX, 77843, USA,
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