The effect of psychosocial stress on muscle activity during computer work: Comparative study between desktop computer and mobile computing products

The impact of remote work using mobile information and communication technologies on physical health: a systematic review

Remote e-working with information and communication technology (ICT) has long been on the rise, with its implementation accelerated by mandatory working from home regulations during the COVID-19 pandemic. This systematic literature review summarises the influencing factors of ICT-based remote e-working (device types, duration of use, user interfaces, etc.) on the physical health (musculoskeletal system and eyes) of knowledge workers. A search in four electronic databases and a manual search in four German journals resulted in 21 articles being included in this review. A bias analysis was conducted for all articles. Unfavourable postures, inappropriate working devices and certain environmental factors may cause a range of physical complaints, even after comparably short periods of time. Mostly, these complaints are greater compared to those experienced when working on a fully equipped stationary computer. Therefore, remote e-working requires careful planning, awareness, and the willingness to embrace working situations that counteract these problems.

An integrated multi-criteria decision-making approach for identifying the risk level of musculoskeletal disorders among handheld device users

In work-from-home (WFH) situation due to coronavirus (COVID-19) pandemic, the handheld device (HHD) users work in awkward postures for longer hours because of unavailability of ergonomically designed workstations. This problem results in different type of musculoskeletal disorders (MSDs) among the HHD users. An integrated multi-criteria decision-making approach was offered for identifying the risk level of MSDs among HHD users. A case example implemented the proposed approach in which, firstly, the best-worst method (BWM) technique was used to prioritize and determine the relative importance (weightage) of the risk factors. The weightages of the risk factors further used to rank the seven alternatives (HHD users) using Vlse Kriterijumska Optimizacija Kompromisno Resenje (VIKOR) technique. The outcomes of the BWM investigation showed that the three most significant risk factors responsible for MSDs are duration of working, poor working posture and un-ergonomic design. The outcome of the VIKOR technique exhibited that computer professionals were at the highest risk among all users. The risk factor priority must be used for designing a working strategy for the WFH situation which will help to mitigate the risks of MSDs.

Perceived software usability and usability-related stress in German craft enterprises

BACKGROUND

Digitalisation is reaching German craft enterprises which must increasingly deal with complex software. The usability of the software is crucial for the effective use in everyday work and insufficient usability is associated with increased stress and strain. It thus seems necessary to identify possible usability-related stressors in craft-enterprise software.

OBJECTIVE

Here we examine how users evaluate the usability of craft-enterprise software and whether usability is associated with perceived work-related stress.

METHODS

To assess the perceived usability of German craft-enterprise software, an online survey was conducted with 161 participants from craft enterprises using a validated usability questionnaire based on ISO 9241-110. In addition, 26 guideline-based interviews were conducted to identify the experience of managers and employees with craft-enterprise software, possible usability-related stress and strain.

RESULTS

Both studies show that craft enterprises use software but only to a limited extend. While back-office administrative processes are routinely supported by software, mobile software support to manage customer service is used less frequently. Increasing complexity of craft-enterprise software is posing growing demands on the users. Software usability was rated to be crucial in the online survey, but the available software is only rated to be acceptable. This was also reflected in the interviews. Participants described usability problems and their relevance as stressors during software use. In consequence, the users experience strain such as feeling overwhelmed and frustrated.

CONCLUSION

It can be concluded that improving the usability of craft-enterprise software should reduce work-related stress and support craft enterprises to master the digitalisation process.

Application of the best-worst method approach for prioritizing risk factors of musculoskeletal disorders among mobile device users: A case study

BACKGROUND: Musculoskeletal disorders (MSDs) are the most common work–related health issues among mobile device (MD) users due to long hour of working during homestay. Various researches have been carried out earlier for identifying the MSD risk factors, though the risk factors’ priority and weightage play an important role for risk management. OBJECTIVE: In the current study, the priority and weightage for MSD risk factor (individual factor, personal factor, psychosocial factor, and subfactors in each factor) were identified using the best–worst method (BWM) for MD users through a case study. METHOD: A framework was proposed for evaluating the risk hierarchy. The rating data provided by decision–makers was analysed using BWM for optimistic risk factor outcomes. A sensitivity analysis was also performed on the prioritized risk factors/subfactors for the consistency check. RESULTS: Research results revealed that personal factor was the most prominent risk factor of MSDs, followed by psychosocial factor and individual factor. Further, the total time spent and gender were identified as most and least dominating risk subfactor of MSDs respectively. The evaluated priority and weightage of MSD risk factors were further validated using sensitivity analysis. CONCLUSION: The obtained outcomes may be helpful in reducing the MSDs risk factors among the MD users by ergonomic improvement.

SV, John EB. Evaluation of surgical skill using machine learning with optimal wearable sensor locations

Evaluation of surgical skills during minimally invasive surgeries is needed when recruiting new surgeons. Although surgeons’ differentiation by skill level is highly complex, performance in specific clinical tasks such as pegboard transfer and knot tying could be determined using wearable EMG and accelerometer sensors. A wireless wearable platform has made it feasible to collect movement and muscle activation signals for quick skill evaluation during surgical tasks. However, it is challenging since the placement of multiple wireless wearable sensors may interfere with their performance in the assessment. This study utilizes machine learning techniques to identify optimal muscles and features critical for accurate skill evaluation. This study enrolled a total of twenty-six surgeons of different skill levels: novice (n = 11), intermediaries (n = 12), and experts (n = 3). Twelve wireless wearable sensors consisting of surface EMGs and accelerometers were placed bilaterally on bicep brachii, tricep brachii, anterior deltoid, flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), and thenar eminence (TE) muscles to assess muscle activations and movement variability profiles. We found features related to movement complexity such as approximate entropy, sample entropy, and multiscale entropy played a critical role in skill level identification. We found that skill level was classified with highest accuracy by i) ECU for Random Forest Classifier (RFC), ii) deltoid for Support Vector Machines (SVM) and iii) biceps for Naïve Bayes Classifier with classification accuracies 61%, 57% and 47%. We found RFC classifier performed best with highest classification accuracy when muscles are combined i) ECU and deltoid (58%), ii) ECU and biceps (53%), and iii) ECU, biceps and deltoid (52%). Our findings suggest that quick surgical skill evaluation is possible using wearables sensors, and features from ECU, deltoid, and biceps muscles contribute an important role in surgical skill evaluation.

Do psychosocial factors mediate the appearance of musculoskeletal symptoms? Evidence of an empirical study about the role of mental workload in computer workers

The emergence of musculoskeletal symptoms (MSSs) in computer workers is a relevant occupational health problem. This study tests a multilevel model of analysis of risk factors in the appearance of musculoskeletal pain and discomfort in computer workers that integrates indicators from different areas: temporal usage patterns, ergonomic factors, psychosocial factors, and individual variables, specifically testing the possible mediating role of the mental workload. A cross-sectional study was performed through online registration with a non-probabilistic sample of 1198 workers from Spanish organizations. The results show that mental workload has a higher association than the rest of the factors with the onset of pain and discomfort in various body areas: neck in men, neck, shoulders and upper back in women. They also support the mediation role of mental workload in the relationship between usage patterns and the appearance of musculoskeletal symptoms. The use of multilevel theoretical models that adequately consider the complexity of the relationships between the different risk factors is necessary for a better understanding and intervention on MSSs in computer workers.

A Systematic Review of EMG Applications for the Characterization of Forearm and Hand Muscle Activity during Activities of Daily Living: Results, Challenges, and Open Issues

The role of the hand is crucial for the performance of activities of daily living, thereby ensuring a full and autonomous life. Its motion is controlled by a complex musculoskeletal system of approximately 38 muscles. Therefore, measuring and interpreting the muscle activation signals that drive hand motion is of great importance in many scientific domains, such as neuroscience, rehabilitation, physiotherapy, robotics, prosthetics, and biomechanics. Electromyography (EMG) can be used to carry out the neuromuscular characterization, but it is cumbersome because of the complexity of the musculoskeletal system of the forearm and hand. This paper reviews the main studies in which EMG has been applied to characterize the muscle activity of the forearm and hand during activities of daily living, with special attention to muscle synergies, which are thought to be used by the nervous system to simplify the control of the numerous muscles by actuating them in task-relevant subgroups. The state of the art of the current results are presented, which may help to guide and foster progress in many scientific domains. Furthermore, the most important challenges and open issues are identified in order to achieve a better understanding of human hand behavior, improve rehabilitation protocols, more intuitive control of prostheses, and more realistic biomechanical models.

Association between comprehensive workstation and neck and upper-limb pain among office worker

OBJECTIVES

Our study aimed to investigate the association between comprehensive workstations and neck and upper-limb pain (NUP) among office workers.

METHODS

This cross-sectional study included 307 office workers (median age, 39 years; 88% men). Workstations (presence of armrest, armrest position, number of monitors used, mouse position, mouse usage, keyboard usage, and keyboard position) were investigated in terms of 17 items and judged as "adequate" or "inadequate." NUP was assessed using a numerical rating scale. NUP locations included the neck, shoulder, elbow, and wrist. In the statistical analysis, outcome variables were the presence of pain in each part, while explanatory variables were the number of inadequate workstations. Logistic regression analyses were conducted with adjustment for age, gender, working duration, and exercise habit.

RESULTS

The prevalence of neck pain was 47% (n = 143), shoulder pain was 50% (n = 153), elbow pain was 7.2% (n = 22), and wrist pain was 13% (n = 40). In the adjusted model, the number of inadequate workstations had significant positive associations with elbow pain (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.06.1.81) and wrist pain (OR, 1.80; 95% CI, 1.17.2.26). However, the number of inadequate workstations was not significantly associated with neck pain or shoulder pain.

CONCLUSIONS

Workstation-related factors (presence of armrest, armrest position, mouse usage, and keyboard usage) were significantly associated with elbow and wrist pain. Our findings suggest that workstations can contribute to elbow and wrist pain in office workers.

Ergonomic evaluation of the risk factors causing pain in the upper part of the body among IT professionals in India

BACKGROUND: In developing countries, the recent increase in computer-related work has considerably increased the occupational complaint of pain. OBJECTIVE: To examine the effects of workstation design, posture and ergonomic awareness on the prevalence of pain for a year in the upper part of the body (eyes, hands, arms, shoulders, lower back, and upper back) among IT professionals in India. METHOD: To investigate the association of risk factors with the prevalence of pain in different body parts, a newly designed online questionnaire titled “A Questionnaire based on ergonomics for IT Professionals” was developed. The psychometric properties of this questionnaire were tested. 110 computer office workers were recruited from IT companies from major cities in India. RESULTS: The confirmation of reliability and lack of redundancy of items was provided by the calculation of internal consistency (Cronbach’s alpha 0.804) and cross-validation. 60% of participants was male. Mean age was 29.73±6.09 years. The prevalence of pain for a year in the upper part of the body was 38.2%. The frequently reported pains were in the neck (22.7%), lower back area (22.7%), and eye strain (21.8%). CONCLUSION: It was identified that long working hours, excessive usage of smartphones, lack of exercise, incorrect workstation adjustments, and incorrect posture were the risk factors for the prevalence of pain.

Head forward flexion, lateral bending and viewing distance in smartphone users: A comparison between sitting and standing postures

BACKGROUND

Smartphones (SPs) are widely used by people of all age groups and genders. Users spend many hours per day on the SPs for different purposes, which imposes significant stress on their musculoskeletal system.

OBJECTIVES

This study explored head forward flexion, lateral bending angle, and viewing distance while working with a SP in sitting/standing postures and one-handed/two-handed grips. The users' performance as well as pain development were also investigated.

METHODS

Participants answered a questionnaire on pain experience before and after SP usage. Neck kinematics of 20 SP users were monitored by a motion analysis system while doing three tasks (typing, video watching, and reading) in sitting and standing postures. Performance was evaluated by number of typed words, amount of errors in typing, and total read words.

RESULTS

The results indicated a significant increase in pain complaints in neck and upper limbs after test completion. Working with SPs in sitting and standing postures were, respectively, associated with greater head forward flexion for watching and viewing distance for two-handed typing tasks. Higher left lateral bending values were measured for one-handed watching and reading tasks in standing posture. The performance measures were superior for two-handed grips in all conditions.

CONCLUSIONS

Overall, using SPs in sitting posture creates greater head forward flexion and lower lateral bending angles in all tasks and grip types. The findings of this study can be used to provide recommendations for SP users.

Stress detection using ECG and EMG signals: A comprehensive study

BACKGROUND AND OBJECTIVE

In recent years, stress and mental health have been considered as important worldwide concerns. Stress detection using physiological signals such as electrocardiogram (ECG), skin conductance (SC), electromyogram (EMG) and electroencephalogram (EEG) is a traditional approach. However, the effect of stress on the EMG signal of different muscles and the efficacy of combination of the EMG and other biological signals for stress detection have not been taken into account yet. This paper presents a comprehensive review of the EMG signal of the right and left trapezius and right and left erector spinae muscles for multi-level stress recognition. Also, the ECG signal was employed to evaluate the efficacy of EMG signals for stress detection.

METHODS

Both EMG and ECG signals were acquired simultaneously from 34 healthy students (23 females and 11 males, aged 20-37 years). Mental arithmetic, Stroop color-word test, time pressure, and stressful environment were employed to induce stress in the laboratory.

RESULTS

The accuracies of stress recognition in two, three and four levels were 100%, 97.6%, and 96.2%, respectively, obtained from the distinct combination of feature selection and machine learning algorithms.

CONCLUSIONS

The comparison of stress detection accuracies resulted from EMG and ECG indicators demonstrated the strong ability and the effectiveness of EMG signal for multi-level stress detection.

New Patterns of Information and Communication Technologies Usage at Work and Their Relationships with Visual Discomfort and Musculoskeletal Diseases: Results of a Cross-Sectional Study of Spanish Organizations

This cross-sectional study analyses the usage patterns of the new communication and information technologies (ICTs) and their relationship with visual discomfort and musculoskeletal diseases in an intentional sample of 1259 workers of Spanish organizations. The usage pattern with the greatest incidence of visual and muscular-skeletal disorders, especially in the wrist and neck, combines the use of laptops and desktops during long working hours. However, the group of workers primarily using mobile devices and working mostly at mobile posts does not appear to be particularly vulnerable to the musculoskeletal diseases and visual fatigue. The ratio of taking a short pause per hour and the implantation of certain technical and preventive measures is related to lower incidence of disorders in the workers as a whole. Current usage of ICTs is very complex and should be addressed using empirical analysis of the different forms of usage and their impacts on health.

Differences in the Mitochondrial and Lipid Droplet Morphology in Female Office Workers With Trapezius Myalgia, Compared With Healthy Controls: A Muscle Biopsy Study

OBJECTIVE

Trapezius myalgia or, more specifically, myofascial dysfunction of the upper trapezius mainly affects women performing jobs requiring prolonged low level activation of the muscle. This continuous low muscle load can be accompanied by a shift to a more anaerobic energy metabolism, causing pain. The aim of the study was to investigate whether morphological signs of an impaired aerobic metabolism are present in female office workers with trapezius myalgia.

DESIGN

Muscle biopsy analysis, using electron and light microscopy, was performed to compare mitochondrial and fat droplet morphology, and irregular muscle fibers, between female office workers with (n = 17) and without (n = 15) work-related trapezius myalgia.

RESULTS

The patient group showed a significantly higher mean area (P = 0.023) and proportion (P = 0.029) for the subsarcolemmal and intermyofibrillar mitochondria respectively, compared with the control group. A significantly lower mean area of subsarcolemmal lipid droplets was found in the patient group (P = 0.015), which also displayed a significantly higher proportion of lipid droplets touching the mitochondria (P = 0.035). A significantly higher amount of muscle fibers with cytochrome c oxidase-deficient areas were found in the patient group (P = 0.030).

CONCLUSIONS

The results of the present study may be indicative for an impaired oxidative metabolism in work-related trapezius myalgia. However, additional research is necessary to confirm this hypothesis.

Evaluating the test-retest reliability of the SLUMP questionnaire for measuring biomechanical issues during laptop use among university students

BACKGROUND

Laptop use may be associated with poor health among University students. However, no psychometrically-sound instrument is available to measure biomechanical issues during laptop computer use in this population.

OBJECTIVE

To evaluate the test-retest reliability of the Student Laptop Use and Musculoskeletal Posture (SLUMP) questionnaire among undergraduate University students.

PARTICIPANTS

We invited 179 undergraduate students from two Health Sciences courses at the University of Ontario Institute of Technology to participate in the study in October 2015.

METHODS

We conducted a test-retest reliability study. The SLUMP questionnaire, which includes 51 questions, was administered twice at a seven-day interval. We used weighted Kappa statistics to calculate test-retest reliability.

RESULTS

Ninety-one students completed the study. 72.5% of the 51 questions achieved a Kw≥0.60 with 29.4% of questions achieving a Kw≥0.80. The reliability was similar for males and females.

CONCLUSION

The SLUMP offers a promising method to measure biomechanical issues during laptop use among University students.

Comparison of muscle activity from upper trapezius and wrist extensors between dominant and non-dominant upper limbs during computer-based tasks

BACKGROUND

Sustained low-level muscle activity occurring during computer-based tasks is associated with the development of WMSDs (work-related musculoskeletal disorders) and this biomechanical exposure may be different between limbs.

OBJECTIVE

To compare muscle activity from dominant and non-dominant upper trapezius (UT) and wrist extensors (WE) during computer-based tasks in real work settings.

METHODS

Forty-five workers were monitored during two hours while performing their usual administrative tasks. Surface electromyography (sEMG) was recorded from UT and WE muscles in both sides. Rest and general exposure variables were calculated.

RESULTS

The 50th percentile demonstrated little muscle activity demand, for both dominant and non-dominant UT and no difference between sides was observed. The dominant WE muscles had lower measures of rest and higher muscle activity when compared with the non-dominant side.

CONCLUSIONS

Differences in sEMG between upper limbs were only found in WE muscles, probably due to the use of the mouse. The overall low-level muscle activity suggests a constant activation of the same motor units for the entire data-collection period, which can be considered harmful for musculoskeletal health.

Developing and evaluating the feasibility of administering the SLUMP questionnaire for evaluating ergonomic exposures to laptop use in university students

BACKGROUND

Laptop computer use may lead to the development of health problems. However, few methods exist to measure laptop use in undergraduate students.

OBJECTIVES

To develop a web-based questionnaire to measure ergonomic exposures to laptop use and to test the feasibility of administration in university students.

METHODS

We pilot tested the administration of the Student Laptop Use and Musculoskeletal Posture (SLUMP) questionnaire to 44 second year undergraduate students. We measured the participation rate, completion of questions, and sought feedback for improving the questionnaire.

RESULTS

The participation rate was 75% (33/44). Students needed 10-12 minutes to complete the questionnaire. Participants suggested adding half hour intervals for questions measuring breaks and improving the clarity by emphasizing the sections focusing on academic, recreational and employment laptop use.

CONCLUSION

Our pilot study suggests that the SLUMP questionnaire is appropriate for "in-class" measurement of ergonomic exposures to laptop use in university students.

The effects of physical and psychosocial factors and ergonomic conditions on the prevalence of musculoskeletal disorders among dentists in Malaysia

BACKGROUND

Musculoskeletal disorders (MSDs) have been recognized as one of the main occupational health problems for dentists. Many studies have suggested that dentists experience work-related pain or discomfort in the neck, shoulder, and back, as well as in other parts of the body.

OBJECTIVE

This study aimed to examine the relationship between specific physical and psychosocial factors and/or ergonomic conditions on MSD symptoms among dentists in Malaysia.

METHODS

A group of 85 dentists was asked to complete a questionnaire to determine whether their complaints were related to physical and psychosocial factors and/or ergonomic conditions in their practices.

RESULTS

Among the nine reviewed body areas, the shoulders were most often affected by symptoms of MSDs (92.7%). Moreover, MSDs of the neck and upper back were most likely to prevent these practitioners from engaging in normal activities (32.9%). In general, no significant differences were found in the prevalence of MSD symptoms in relation to gender, age, body mass index, years in practice, number of patients, and frequency of breaks.

CONCLUSIONS

Our results were consistent with those reported in other studies that focused on MSD problems among dentists in other countries. To reduce the prevalence of MSDs, more attention should be paid to instituting ergonomically sensible approaches in the dental practice setting.