The role of experience in night work: Lessons from two ergonomic studies

The purpose of this article is to analyze some connections between experience, health and work, especially in the field of night work. As a result of the baby boom, the proportion of elderly workers is steadily increasing, while at the same time many workers are reaching retirement age and being replaced by younger people. And, in the same time, there is an overall gradual increase in shift work and night work. To our knowledge, worker experience has not been extensively studied in this context. This was our focus in studying work activity in two very different situations, in a hospital and in a steel industry.In these two studies we observed that the experienced workers endeavor to plan ahead, especially at night. They do this to limit fatigue and to avoid emergencies and ensure that work is stress-free and as far as possible under control. But experience not only brings workers to plan ahead, it also enables them to do so, thanks to the resources it confers: gaining familiarity with tasks and acquiring the ability to identify critical situations, gaining knowledge about themselves and awareness of situations that cause difficulty; and gaining a better overview of the collective aspects of their work and of ways to share tasks or obtain assistance.They are able to undertake these strategies thanks to specific skills and capacities they have built along their professional career, which notably leads them to find the best trade-off between several goals, possibly contradictory.Such experience is especially valuable at night, when the worker is tired, and when there are fewer supervisors present. This experience can only be gained, however, if the work environment fosters its acquisition and provides an opportunity to make use of it, especially during the night shift and especially with respect to planning tasks ahead of time.     

The perceived importance and the presence of creative potential in the health professional's work environment

The value of creative employees to an organisation's growth and innovative development, productivity, quality and sustainability is well established. This study examined the perceived relationship between creativity and work environment factors of 361 practicing health professionals, and whether these factors were present (realised) in their work environment. Job design (challenges, team work, task rotation, autonomy) and leadership (coaching supervisor, time for thinking, creative goals, recognition and incentives for creative ideas and results) were perceived as the most important factors for stimulating creativity. There was room for improvement of these in the work environment. Many aspects of the physical work environment were less important. Public health sector employers and organisations should adopt sustainable strategies which target the important work environment factors to support employee creativity and so enhance service quality, productivity, performance and growth. Implications of the results for ergonomists and workplace managers are discussed with a participatory ergonomics approach recommended.

Practitioner summary: Creative employees are important to an organisation's innovation, productivity and sustainability. The survey identified health professionals perceive a need to improve job design and leadership factors at work to enhance and support employee creativity. There are implications for organisations and ergonomists to investigate the creative potential of work environments.     

Impact of multimodal feedback on simulated ergonomic measurements in a virtual environment: A case study with manufacturing workers

The purpose of this study was to evaluate the impact of multimodal feedback on ergonomic measurements in a virtual environment (VE) for a typical simulated drilling task. In total, sixty male manufacturing industry workers were divided into five groups. One group performed the working task in a real environment (RE), and ergonomic measurements for this group were used as the baseline for evaluation. The other four groups performed the same task in a virtual environment with different feedback treatments (visual with or without auditory and/or tactile feedback). Five indices – task completion time, maximum force capacity reduction, body part discomfort, rated perceived exertion, and rated task difficulty – were used to evaluate the measurements of each of the four treatments in VE in comparison to the baseline group in RE. The results indicate that the five indices for each of the four treatment groups were significantly higher than those of the RE group. Moreover, the indices of the visual‐only group were significantly higher than those of the other three groups with auditory and/or tactile feedback treatments. The findings of this study can provide a guideline for ergonomic evaluations of work designs in VE and for establishing a virtual reality simulation system. © 2011 Wiley Periodicals, Inc.     

Flexible workspace design and ergonomics training: impacts on the psychosocial work environment, musculoskeletal health, and work effectiveness among knowledge workers

A macroergonomics intervention consisting of flexible workspace design and ergonomics training was conducted to examine the effects on psychosocial work environment, musculoskeletal health, and work effectiveness in a computer-based office setting. Knowledge workers were assigned to one of four conditions: flexible workspace (n=121), ergonomics training (n=92), flexible workspace+ergonomics training (n=31), and a no-intervention control (n=45). Outcome measures were collected 2 months prior to the intervention and 3 and 6 months post-intervention. Overall, the study results indicated positive, significant effects on the outcome variables for the two intervention groups compared to the control group, including work-related musculoskeletal discomfort, job control, environmental satisfaction, sense of community, ergonomic climate, communication and collaboration, and business process efficiency (time and costs). However, attrition of workers in the ergonomics training condition precluded an evaluation of the effects of this intervention. This study suggests that a macroergonomics intervention is effective among knowledge workers in office settings.     

The impact of night work on psychological well-being

This study tested the efficacy of selected personality, behavioural, and social/organizational variables as predictors of adaptation to night work. Sixty female student nurses were studied during their first IS months of shiftwork. Twenty-two worked on rotating day and afternoon shifts throughout, while the remaining 38 began regular night shifts after six months. Psychological symptoms were measured at baseline (Stage 1), six months (Stage 2) and 15 months (Stage 3). Repeated measures analysis of variance revealed a significant shift group x symptoms interaction (p < 0·05) between Stages 2 and 3. Only the night workers displayed a significant increase (Tukey HSD: p < 0·01) in symptoms between Stages 1 and 3. Multiple regression analysis revealed that neuroticism and perceived work/nonwork conflict predicted symptoms at Stage 2. Night work, social support from supervisors, and morningness were predictors at Stage 3. These results suggest that organisational, behavioural, and physiological factors moderate the impact of night work on psychological well-being, and personality factors do not.     

The impact of ergonomic intervention on individual health and corporate prosperity in a telecommunications environment

This paper is a summary of several papers published in different journals and conference proceedings. The contents deal with the incidence of load related musculoskeletal illness of female workers exposed to various workloads. Furthermore, the changes in workload due to improved workplace design and the effect on the incidence of musculoskeletal illness was evaluated. The sick-leave due to musculoskeletal illness was reduced from 5·3% to 3·1% and the reduction in turn-over from 30·1% to 7·6%. The cost and the benefits of this ergonomic intervention were analysed, and showed that an investment of NOK. 350 000 produced total savings of NOK. 3 200 000.

Postural load was assessed by recording electromyography (EMG) on the upper part of musculus trapezius, postural angles of the upper arm and flexion/extension of the head and back. A quantitative relationship was found between the static trapezius load and the development of musculoskeletal sick-leave, related to the length of employment. Indications were found that certain factors were associated with reduced incidence of musculoskeletal illness. These were:

? increasing the number and total duration of trapezius load below 1% to 2% MVC (Maximum Voluntary Contraction);

? reducing the magnitude of flexion angle of the upper arm in the sagittal plane and distributing the work between flexors and extensors; and

? a more dynamic work pattern of the upper arm.

The relationship between postural load and musculoskeletal injury was studied in comparable groups of female workers with respect to age, working hours per day and time of employment. Psychosocial problems, spare time activities and living habits of the workers did not show any significant differences across the groups. The results from this study indicate that:

? the static trapezius load must be kept at a minimum;

? a median arm flexion should be less than 15° and a median arm abduction less than 10°. These values seem roughly to approach an acceptable arm position; and

? a forward median flexion of the back of less than 20° seems not to lead to a higher rate of low back pain for workers with long periods of employment.     

Occupational stress in submariners: The impact of isolated and confined work on psychological well-being

This study aimed to identify work-related and personal factors associated with occupational stress in submariners. Work and well-being questionnaires were distributed to 219 male submariners (mean age 34 years), as part of a larger cohort study involving a stratified sample of 4951 Royal Navy (RN) personnel. The stress rate in submariners was 40%; significantly higher than the stress rate in the general RN, although once demographic factors were controlled for in a matched control sample, this difference was no longer significant. A summary model accounted for 49% of the variance in submariner stress, with key differences emerging between the occupational factors associated with stress in submariners and in the general RN. The longitudinal nature of this study permits stress in submariners to be monitored over 5 years, which will provide valuable insights into the chronicity of stress in this specialised occupational group.

Statement of Relevance: This paper contributes to the current literature on the negative impact of working in isolated conditions. It is demonstrated that occupational stress in submarines can be partially explained using current theories of stress in the workplace. However, the constraints of a restricted environment introduce additional factors which can also be associated with occupational stress.     

The work compatibility improvement framework: an integrated perspective of the human-at-work system

Lapos;appareil a été concu de façon à reproduire les caractéristiques principalos do la machine à trier les lottres en usage à la Poste beige, ot à permettre en plus la détection automatique des erreurs et Le fonctionnement soit à vitesse imposée (VL) soifc à vitesse libre (VL). Dix-huit opératcurs entrainés ont aervi de sujets. lis ont d'abord trié 500 destinations à chacune des 4 vitessos imposées (40, 50, 60 et 70/minnte) en memo temps qu'unmemo nombre de destinations a VL. L'augmen. tation do la cadence à VI a'accompagne d'une augmentation importante de proportions d'errours, do reponses tardives et d'omissions. II y a de fortes differences individuelles maia pour 1'enaomble du groupo on pout estimcr que lo fait d'imposer une cadence egalo a la vitesse moyenne adoptee a VL ferait que 80 pourcent seule-mont des destinations recovraient une reponse en temps utile, dont environ 10 pourcent d'errours (contro moins de 2 pourcent a VL). Quand la cadonco imposed est suporieuro a la vitosso realiseo par un sujet a VL, il y a presque toujours plus d'erreurs a VI. Au cours d'une seance, chaquo sujet a travaille a VI a une cadence ogale a la vitesse qu'il venait do realiser a VL. On a de nouveau observe une proportion d'erreurs plus importanto a VI (9 pourcent au lieu de 3 pourcent) bien que la vitesse effective (en termes de reponses donnees en temps utile) fut inferieure. L'analyse detaillee d'un echantillon de cycles à VI a montré quo la prossion de vitesse présente un caraétoro cumulatif. Les erreurs et les éeponses tardives so produisent principalemont apres vino reponse doruiSe dans lo voisinage ou après la fin do la periode d'acceptation. D'autre part, uno tendance a n'omettre de ropondro quo dans Los cas de pression de vitesso extreme a 6te miso en evidence. Tous cos resultats ont été obtenus avec presentation anticip6o do la destination suivanto a chaque cycle. Uno comparaison avec lo travail a VL sans presentation anticipee montre que dans la condition precécédente los sujets lisent generalement la destination suivanto avant de répondre.     

The impact of work configuration,target angle and hand force direction on upper extremity muscle activity during sub-maximal overhead work

Overhead work has established links to upper extremity discomfort and disorders. As many jobs incorporate working overhead, this study aimed to identify working conditions requiring relatively lower muscular shoulder load. Eleven upper extremity muscles were monitored with electromyography during laboratory simulations of overhead work tasks. Tasks were defined with three criteria: work configuration (fixed, stature-specific); target angle (?15°, 0°, 15°, 30° from vertical); direction of applied hand force (pulling backwards, pushing forwards, downwards, sideways, upwards). Normalised electromyographic activity was greater for fixed configurations, particularly when pulling in a backward direction (total activity = 108.3% maximum voluntary exertion (MVE)) compared to pushing down or forward (total activity ranging from 10.5 to 17.3%MVE). Further, pulling backwards at angles of –15° and 0° showed the highest muscular demand (p < 0.05). These results suggest that, if possible, positioning overhead work in front of the body with exertions directed forwards will result in the lowest upper extremity muscle demand.

Statement of Relevance: Overhead work pervades occupational settings and is associated with risk of upper extremity musculoskeletal disorders. The muscular intensity associated with performing overhead work was assessed in several combinations of work placement and hand force direction. These findings should have utility for designing overhead work tasks that reduce muscular exposure.     

Influences on the use of observational methods by practitioners when identifying risk factors in physical work

Most observational methods for musculoskeletal disorder risk assessment have been developed by researchers to be applied in specific situations, and practitioners could find difficulties in their use in real-work conditions. The main objective of this study was to identify the factors which have an influence on how useful the observational techniques are perceived to be by practitioners and to what extent these factors influence their perception. A survey was conducted on practitioners regarding the problems normally encountered when implementing these methods, as well as the perceived overall utility of these techniques. The results show that practitioners place particular importance on the support the methods provide in making decisions regarding changes in work systems and how applicable they are to different types of jobs. The results of this study can serve as guide to researchers for the development of new assessment techniques that are more useful and applicable in real-work situations.     

Evaluating the impact of the simulation environment on experimentation results

Simulation has become the tool of choice for advanced computer architecture research. Simulation model abstraction as well as compiler specifics can have significant impact on the observed performance trends and may lead to incorrect conclusions. This study presents a methodology that compares the predicted performance impact of several architectural techniques measured on a variety of simulator and compiler configurations. A significant difference in speedup between experiments indicates that a technique is sensitive to this particular variation. The results demonstrate a strong but non-uniform relationship between modeling abstraction and measurement error, as well as a significant sensitivity to the compiler.     

Exploring the impact of changes in work organisation on employees

The paper seeks to provide a context for debate on the impact of new work organisation on employees. By reviewing new work organisation literature and considering a practical case example the paper calls for further research which demonstrates a strategic and implementation approach that can yield benefits for business and employees.     

The effects of occupational health and safety management on work environment and health: a prospective study

According to Norway's Internal Control Regulation, all companies are required to have an occupational health and safety (H&S) management system. This study investigated the effects of implementing or improving occupational H&S management on the work environment, H&S-related behaviour and musculoskeletal health of workers in small and medium-sized companies. A one-year prospective cohort study, using self-administered questionnaires, was performed among the managers and blue-collar workers in 226 motor vehicle repair garages. Out of 1559 workers that responded at baseline 721 workers could be identified at follow-up. These 721 workers were included in the study. The workers in companies with improved H&S management from baseline to follow-up reported increased satisfaction with the H&S activities at the garage; improved support from management and colleagues; improved health-related support and control; and increased participation in H&S activities.     

The impact of abnormal hours of work on various modes of information processing: a process model on human costs of performance

Abstract

Most laboratory experiments on task performance show a performance deterioration due to a disturbed sleep/wake pattern. Field studies on performance, errors and accidents during night and shiftwork conditions, however, do not provide sufficient converging evidence in this respect. The conflicting results of field studies are probably caused by the measurement methods being based on the material aspects of performance, in which many confounding factors play an important role. Though workers seem to make more errors at night and react less efficiently, the time-of-day effect will often be overshadowed by the influence of situational, task-related and person-related factors. In particular the nature of the involved mental processes, the psychophysiological state of the person, and the invested effort are important for the outcome of performance. With respect to the nature of the involved mental processes, a taxonomy of mental tasks is presented, in which two types of mental tasks are distinguished with respect to their attention-demanding nature.

With respect to the psychophysiological state of the person and the invested effort, it is concluded that (a) the state and with that the performance capacity can be considered as sub-optimal when working during abnormal hours, and (b) effort is required to compensate this sub-optimal state in order to meet the task-demands. Hence, in order to determine the effect of a disturbed sleep/wake pattern on performance, a more appropriate method may be to focus research also on the effects on the person who is performing the task rather than to concentrate research on the effects on the material outcome of performance alone. Therefore a process model of human costs of performance at abnormal hours of work is presented.     

Influence of shift work in process industry on workers' occupational health,productivity, and family and social life: An ergonomic approach

Shift work is a major feature of modern work practices. It involves working at times considered unconventional for most workers, such as at night. Although the community often benefits from such work practices, shift work can be hazardous for both the workers and the community. There are increased risks for accidents and errors, increased sleepiness and fatigue due to difficulties sleeping, increased health problems, and disruptions to family and social life. More shift workers complained of sleep disturbance, poor sleep quality, tiredness at awakening, and sleepiness in work than did non‐shift workers. More shift workers also complained of gastrointestinal disturbances than did non‐shift workers. The aim of this article is to provide general information on shift work, work schedules, and the effects of work schedules on sleep, fatigue, performance, the health of the human operator, and productivity. © 2010 Wiley Periodicals, Inc.     

A systematic review – physical activity in dementia: The influence of the nursing home environment

Most older persons with dementia living in nursing homes spend their days without engaging in much physical activity. This study therefore looked at the influence that the environment has on their level of physical activity, by reviewing empirical studies that measured the effects of environmental stimuli on the physical activity of nursing home residents suffering from dementia. The electronic databases PubMed, PsycINFO, EMBASE, CINAHL and the Cochrane Library were used for the search. The search covered studies published between January 1993 and December 2012, and revealed 3187 abstracts. 326 studies were selected as potentially relevant; of these, 24 met all the inclusion criteria. Positive results on the residents' levels of physical activity were found for music, a homelike environment and functional modifications. Predominantly positive results were also found for the small-scale group living concepts. Mixed results were found for bright or timed light, the multisensory environment and differences in the building footprint.     

Low back pain in farmers: The association with agricultural work management,disability, and quality of life in Korean farmers

This study aimed to identify the associations among low back pain (LBP), LBP‐related disability, agricultural working condition management, and quality of life (QOL) in Korean farmers. Demographic information, agricultural work management, and outcomes of LBP were obtained by standardized questionnaires (Oswestry Disability Index [ODI] for disability and European Quality of Life‐5 Dimensions‐3‐Level version [EQ‐5D‐3L] for QOL). Presence of LBP was determined if the LBP had lasted longer than 1 week or had been more frequent than once a month, and presence of LBP‐related disability was determined if the ODI score was more than 12. Poor health checkups (OR [odds ratio] = 1.70–86, p < .05), were positively associated with LBP, and working at dawn (OR = 1.85–1.96, p < .05), was positively associated with LBP‐related disability after adjusting related demographic factors. EQ‐5D‐3L indexes were significantly lower in participants with LBP (0.83 ± 0.17 vs. 0.92 ± 0.06, p < .001) and disability (0.81 ± 0.18 vs. 0.93 ± 0.05, p < .001). This study showed that the presence of LBP was related to poor health checkups and that LBP‐related disability was related to a poor working time schedule. These results indicate poor QOL and suggest the need for coping strategies such as regular health checkups and a proper working time schedule.     

Estimation of energy expenditure in a work environment: Comparison of accelerometry and oxygen consumption/heart rate regression

The aim of this study was to compare estimation of energy expenditure (EE) in working environments, either from accelerometry or from an individual oxygen consumption/heart rate ([Vdot]O₂/HR) regression curve. The study participants were 46 volunteer workers aged 27±6 years old. A significant correlation between EE predicted by the [Vdot]O₂/HR curve and the accelerometer was observed (r=0.78, p <0.01). However, more disparities were observed between the two methods when the mean job intensity was not within 16% and 23% higher than resting HR. The accelerometer overestimated by a mean of 34.4% the prediction by [Vdot]O₂/HR regression if the intensity of the task was lower than a total of 1000 kcal/shift and underestimated the prediction by a mean of –24.9% if EE estimation of the work shift was higher than a total of 1500 kcal/shift. Despite a high correlation between both methods in the whole group, EE evaluated by accelerometry does not correspond to EE predicted by the [Vdot]O₂/HR regression curves when evaluated individually.     

Applying New JIT—Toyota's global production strategy: Epoch-making innovation of the work environment

In order to strengthen management technology strategy, the author has recently developed a new management technology principle, New JIT, based on TMS, TDS, TPS and TQM-S. In developing “Global Marketing” that can win the global competition for quality and cost, the key for domestic and foreign companies is to successfully achieve “Global Production” that enables simultaneous production start-up (the same quality and production at optimal locations) throughout the world. This paper analyzes and proves the significance of strategically applying New JIT—a global production strategy activity called AWD6P/J—for epoch-making innovation of the work environment, as verified at Toyota. While many vehicle assembly shops depend on a young, male workforce, innovation in optimizing an aging workforce is a necessary prerequisite of TPS—a production strategy of New JIT. Elements necessary for enhancing work value and motivation, and work energy, including working conditions and work environment (amenities and ergonomics), were investigated through objective survey and analyzed from labor science perspectives.     

Low back injury risk during repositioning of patients in bed: the influence of handling technique,patient weight and disability

The objective of the study was to investigate the low back load during repositioning of patients in bed and to assess the influence of patient's weight and disability. Nine female health care workers (HCWs) carried out six patient-handling tasks with different patient weight (59 ± 1, 83 ± 2 and 110 ± 4 kg) and handicap (hemiplegia, paraplegia and near-paralysis). The tasks were performed with optional use of simple, low-tech assistant devices (draw and sliding sheets). Peak low back compression exceeded the National Institute for Occupational Safety and Health action level of 3400 N in 25% of all trials (418). The influence of the HCW, i.e. the technique and assistive devices used, was higher than the effect of weight and disability in all tasks studied. ANOVA showed that on average for the six tasks 37%, 10% and 6% of the variance in low back loading was caused by variation in the factors HCW, patient's weight and disability, respectively. The result of this study is relevant for HCWs. It is shown that the repositioning technique and use of friction-reducing devices have higher influence on the low back load of the HCW than the patient's weight and disability.