Ergonomics

Published by Taylor & Francis
Online ISSN: 1366-5847
Publications
Article
This paper briefly reviews research studies of interest to environmental ergonomists. It includes some recent work on the health effects of office lighting, especially the effects of daylighting, fluorescent lighting and full-spectrum lighting. It also covers studies of indoor air quality in offices, especially investigations of localized air filtration and the sick building syndrome. It argues the value of a systematic, ergonomics approach to designing the built environment.
 
Article
The ten Basic Fitness Tests of Fleishman and the five tests of the Army Physical Combat Proficiency Test were administered to 149 Special Forces soldiers ranging in age from 19-39. The means and standard deviations of each test by age group and the relative performance of the separate age groups on the tests are presented. Nine of the 15 tests (Dodge-Run-Jump, Mile Run, Extent Flexibility, 600-Yard Run, Cable Jump, Dynamic Flexibility, Softball Throw, Grenade Throw, and Pull-ups) showed a relatively consistent downward trend from 19 to approximately 30 years of age. The remaining six tests (Shuttle Run, Hand Grip, Leg Lifts, Balance, Low Crawl, and Horizontal Ladder) did not show the downward trend to age 30 and did not show a drop at age 30. From age 30 to 39 none of the tests showed a consistent downward trend, while four showed a relatively consistent improvement in performance, four showed relatively stable performance and the means of seven tests were somewhat erratic.These results were inconsistent with those of an Indian study which concluded that the ageing process commences at about 30 years and accelerates after 37 years.
 
Article
Activity theory has been successfully applied in diverse schools of psychology with particularly extensive work in the fields of education, ergonomics, human factors and industrial-organizational psychology. However, existing efforts of translation and formulation in English suffer from certain limitations. These limitations include the blurring between Vygotsky's socio-cultural theory of the development of mind and activity theory, the restriction of activity theory in its entirety to the version offered by Leont'ev, errors in the interpretation of some basic concept and terminology, reliance on studies that use obsolete methods, and failure to consider the Russian work in activity theory in its entirety. This last problem results in the omission of the recent advances in engineering psychology and educational psychology in the former Soviet Union that facilitates the application of activity theory to practical problems. This paper is a description of the evolution of basic theory, concepts and terminology relevant to practitioners--particularly in the field of ergonomics.
 
Article
Three experiments have been conducted to determine the effects of the frequency of whole-body vibration on comfort in the range 0·5–5·0 Hz. With vertical sinusoidal vibration the responses of 40 subjects (20 males and 20 females) were determined at two vibration magnitudes for each of the 11 preferred third-octave centre frequencies from 0·5ndash;5·0Hz. The responses of a subgroup of 10 male subjects to octave bands of vertical random vibration centred on 0·5,10, 2·0 and 40 Hz were determined in the second experiment. Twenty male subjects participated in the third experiment with lateral sinusoidal vibration in the 0·5–5·0 Hz range. The results have been compared with the findings of earlier experiments and the current International Standard.It is concluded that with vertical motion there were small differences between the responses of male and female subjects. There was little effect of vibration magnitude on the frequency dependence of vibration discomfort. Random vibration produced slightly greater discomfort than sinusoidal vibration but with the same frequency dependence. The findings are broadly compatible with the results of previous experimental studies but, for the vertical axis, differ from the frequency dependency given in the International Standard. A simple alternative frequency dependency based on the present data combined with earlier findings is defined for predicting the discomfort of vertical vibration in the range 0·5–100 Hz.
 
Article
Standards organizations have given considerable attention to the problem of work-related musculoskeletal disorders. The publication of international standards for evaluating working postures and movements, ISO 11,226 in 2000 and EN 1,005-4 in 2005, may be considered as a support for those involved in preventing and controlling these disorders. The first one is a tool for evaluation of existing work situations, whereas the latter one is a tool for evaluation during a design/engineering process. Key publications and considerations that led to the content of the standards are presented, followed by examples of application.
 
Article
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 15 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 less than 0.05) between Stages 2 and 3. Only the night workers displayed a significant increase (Tukey HSD: p less than 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.
 
Article
The traditional methods for assessing muscle performance have been applied to the wheelchair athlete with some success. In wheelchair athletics, as in able-bodied athletics, there are a number of short races taxing the anaerobic capacity. Previous work from this laboratory described an anaerobic test specifically for wheelchair athletes. This essentially was a modification of the ‘Wingate test’ protocol, enabling a wheelchair athlete using his own wheelchair to work against a friction loaded flywheel over a 30 s period. The objectives of the present study were to use this wheelchair ergometer (WERG) to investigate (1) the week to week stability of power measurements, (2) the effects of varying the friction load and (3) the relationship between power measurements and sprint performance times.
 
Definition of anthropometric data.
Detailed information of the subjects.
Mean of anthropometric dimensions in Iranian ethnicities.
Article
Unlabelled: Anthropometric data can be used to identify the physical dimensions of equipment, furniture, clothing and workstations. The use of poorly designed furniture that fails to fulfil the users' anthropometric dimensions, has a negative impact on human health. In this study, we measured some anthropometric dimensions of Iranian children from different ethnicities. A total of 12,731 Iranian primary school children aged 7-11 years were included in the study and their static anthropometric dimensions were measured. Descriptive statistics such as mean, standard deviation and key percentiles were calculated. All dimensions were compared among different ethnicities and different genders. This study showed significant differences in a set of 22 anthropometric dimensions with regard to gender, age and ethnicity. Turk boys and Arab girls were larger than their contemporaries in different ages. According to the results of this study, difference between genders and among different ethnicities should be taken into account by designers and manufacturers of school furniture. Practitioner summary: In this study, we measured 22 static anthropometric dimensions of 12,731 Iranian primary school children aged 7-11 years from different ethnicities. Descriptive statistics such as mean, standard deviation and key percentiles were measured for each dimension. This study showed significant differences in a set of 22 anthropometric dimensions in different genders, ages and ethnicities.
 
Article
The Harvard pack test and an 11 min progressive treadmll test (belt speed 80m min incline increasing by l·4%min for 10min) have been applied to 378 healthy male mine rescue workers aged 20-45 yr. During the treadmill test measurements were made of ventilation, cardiac frequency and stroke volume. Measurements were also made of ventilatory capacity, body dimensions, fat free mass and heart volumeThe results show that the Harvard pack index (HPI) may be predicted from the last minute cardiac frequency (LMfC) during the progressive treadmill test according' to the following relationship: HPI = 147−0·22 age−0·39 LMfC, the coefficient of variation about this relationship is 10·4%The inclusion in the prediction relationship of fat free mass, cardiac frequency at an oxygen uptake of 67mmol min and stroke volume which in combination are significantly correlated with the HPI, also of leg length, ambient temperature and smoking history, which are not so related, do not materially improve the accuracy of the prediction. Current smoking is associated with a relatively low quantity of body fat and high ventilation minute volume during exercise but is not correlated with the exercise cardiac frequency. Evidence is presented why the submaximal cardiac frequency reflects the physical condition of the subjects.
 
Synthetic landmarks over the body shape
Article
A statistical body shape model (SBSM) for children was developed for generating a child body shape with desired anthropometric parameters. A standardised template mesh was fit to whole-body laser scan data from 137 children aged 3-11 years. The mesh coordinates along with a set of surface landmarks and 27 manually measured anthropometric variables were analysed using principal component (PC) analysis. PC scores were associated with anthropometric predictors such as stature, body mass index (BMI) and ratio of erect sitting height to stature (SHS) using a regression model. When the original scan data were compared with the predictions of the SBSM using each subject's stature, BMI and SHS, the mean absolute error was 10.4 ± 5.8 mm, and 95th percentile error was 24.0 ± 18.5 mm. The model, publicly available online, will have utility for a wide range of applications. Practitioner Summary: A statistical body shape model for children helps to account for inter-individual variability in body shapes as well as anthropometric dimensions. This parametric modelling approach is useful for reliable prediction of the body shape of a specific child with a few given predictors such as stature, body mass index and age.
 
Article
Myoelectric activities of several trunk muscles were measured when subjects performed several common table-work tasks. At the same time, the contraction forces of these muscles were calculated using a biomechanical model. The measured myoelectric activities were transformed from microvolt to force data by means of regression analysis using a set of calibration experiments over the force range of interest. We suggest that that technique is more meaningful than relating the myoelectric data to, for example, a maximum voluntary contraction.Loading of the spine was generally low in office table work. Further, the load levels were only marginally influenced by such factors as table-chair adjustment, manuscript location, and work tasks. We believe that the type of table work studied here does not influence the spine by imposing high loads, but rather by its static nature.
 
Mean end cardiorespiratory and metabolic values. 
Article
The aim was to compare physiologic responses during exhaustive runs performed on a treadmill at 100 and 120% maximal aerobic speed (MAS: the minimum speed that elicits VO2max). Fourteen subelite male runners (mean +/- SD; age = 27+/-5 years; VO2max = 68.9+/-4.6 ml/kg(-1)/min(-1); MAS = 21.5+/-1 km/h(-1)) participated. Mean time to exhaustion tlim100% at 100% MAS (269+/- 77s) was similar to those reported in other studies. However, there was large variability in individual tlim100% MAS (CV = 29%). MAS was positively correlated with VO2max (r = 0.66, p<0.05) but not with tlim100%) MAS (r = -0.50, p<0.05). tlim100% MAS was correlated with t(lim) at 120% MAS (r = 0.52, p < 0.05) and to blood pH following the rest at 120% MAS (r = -0.68, p<0.05). The data suggest that running time to exhaustion at MAS in subelite male runners is related to time limit at 120% (tlim120%) MAS. Moreover, anaerobic capacity determined by the exercise to exhaustion at 120% MAS can be defined as the variable 'a' in the model of Monod and Scherrer (1954).
 
Article
The aim of the present paper is to examine whether the motor deficiency related to paraplegia could determine a handicap in the execution of a manual task. The test task corresponded to the transport and positioning of a load in the sagittal plane. Sensorimotor behaviour was considered, i.e. the performance, the dynamics of the movement studied with a forceplate, and the muscular patterns studied by surface electromyography. A group of twelve paraplegics (T4 level) was considered in reference to a group of eight able-bodied subjects. The results established dissimilarities between the two groups: performance was lesser in paraplegics, dynamics of the movement and muscular patterns were different. Paraplegics showed a more important activity in the residual muscles of the trunk and the scapular girdle: more of these muscles were activated and their activation was higher and longer. Results were interpreted with regard to postural adjustments related to the execution of a task. Thus, it was shown that due to their sensorimotor deficiency, paraplegics adopted a substitution postural strategy to face the perturbation due to the movement, which was identical to the able-bodied subjects. Increased muscular activity located in certain muscles suggested a higher physiological strain in paraplegics. Ergonomic recommendations to avoid or at least to limit the possible handicapping character of working situations corresponding to manual tasks were suggested.
 
Article
Three-dimensional morphological variations in the human face were analysed using digital models of the human face, and the usefulness of such analysis in designing industrial products was demonstrated by validating spectacle frame designs based on an original sizing system developed based on the analysis. A normalized model of the three-dimensional face form was made for each of 56 young adult Japanese males. The morphological distances between subjects were defined, and subjects were divided into four groups based on analysis of the distance matrix. A prototype spectacle frame was designed for the average form of each of the four groups. Tightening force of the prototype frames was adjusted using the materialized average forms with soft material placed at the nasal bridge and side of the head. Four prototype frames as well as a conventional frame were evaluated using sensory evaluation and physical measurement of the pressure and slip in 38 young adult male subjects. For each of the 38 subjects, prototype frames were ranked according to the morphological similarity of the subjects and the average form of the four groups: the frame designed for the average form of the group most similar to the subject was #1, the frame designed for the average form of the next most similar group was #2, and so on. For the groups with smaller or narrower faces, new frame #1 was most preferred and had the best overall fit, smallest slip sensation and largest pressure sensation. The groups with larger or wider faces preferred tighter frames than new frame #1, because they were concerned that the frames might slip, although the frames did not. Most of the subjects habitually wore spectacles, and the reason that groups with larger or wider faces preferred tighter frames was thought to be that they were accustomed to tighter fitting frames.
 
Article
A 16-month longitudinal study was made of workers who perform physically demanding jobs. In a previous study some of these workers were found to have a history of low back disorders sufficient to miss work, and others not. All were asymptomatic at that time. To further quantify the association between various personal and psychosocial parameters that linger due to a history of low back disorders and how they may change after another 16 months of work. Originally, 72 workers were recruited from heavy industry; 26 of whom had a history of disabling low back disorders sufficient to miss work. In the follow-up study, 46 responded all of whom remained at work injury free, 13 belonged to the 'history of back disorders' category. While the earlier study suggested that having a history of low back disorders is associated with a larger waist girth, a greater chronicity potential as predicted from psychosocial questionnaires, perturbed flexion to extension strength and endurance ratios, and widespread motor control deficits across a variety of tasks some of which resulted in high back loads, the follow-up showed no difference in reported physical symptoms, or perceived pain over the 16 months. Both groups changed their responses from the original data collection to the 16-month follow-up with the net result of psychosocial distinguishing traits, in those with a history, diminishing. It was concluded that time and work appear to be healing.
 
Article
The main purpose of this study was to ascertain musculoskeletal and cardiovascular capacity among ageing employees in relation to workload over a period of 16 years. The data were obtained by physical capacity tests and ratings of perceived exertion (RPE) during working day. The study group consisted of 89 subjects, who were all employed in the municipal branch and were on average 51.9 years old at the beginning of the follow-up period in 1981 and 67.3 years in 1997, when the most of the subjects had retired (with only two subjects still working). During the 16-year follow-up period, age-related decline in physical capacity was observed. Nevertheless the improvement in flexibility of spine and in isometric trunk muscle strength compared with the same age subjects was more common among the subjects with high workload than among the subjects with low workload. However, among the subjects with high workload, physical capacity was poorer than among the subjects with low workload, especially among the women. The results suggest the conclusion that there are differences in workers' physical capacity in relation to their perceived workload during working life. These differences remained when the subjects had retired. Interestingly, those who had high workload had lower muscle strength than those who had low workload. This may indicate that high physical workload does not have any training effect on the muscle strength of ageing workers.
 
Article
Maximum oxygen intake ([Vdot]o2max), lung ventilation, heart rate, skinfolds, haematocrit and haemoglobin concentration were measured in 40 British women aged 17-27 years during 5 min maximum ergometer exercise. Repeatable values were obtained in 2 or 3 attendances. [Vdot]o2max for 20 subjects preparing for Alpine skiing was 43.3 ml/kg min (range 37.8-50.8 ml/kg min). [Vdot]o2max for 20 laboratory technicians was 36.5 ml/kg min (range 30.9-42.2 ml/kg min). The variation in [Vdot]o2 max in subjects followed over 6-12 weeks ranged from + 3 to + 30%. The variation in [Vdot]o2 max in 6 skiers followed over 2-6 years ranged from — 10 to +45%. The results are compared with other series on British women and with published results from other countries.
 
Article
Unlabelled: The purpose of this study was to investigate the possible relation between self-reported neck symptoms (aches, pain or numbness) and use of computers/cell phones. The study was carried out as a cross-sectional study by posting a questionnaire to 15,000 working-age persons, and 15.1% of all respondents (6121) reported that they very often experienced physical symptoms in the neck. The results showed that they also had many other symptoms very often, and 49% used a computer daily at work and 83.9% used cell phones. We compared physical/mental symptoms of persons with symptoms in the neck quite often or more, with others. We found significant differences in the physical/mental symptoms and use of cell phones and computers. The results suggest taking into account in the future that those persons' symptoms in the neck can be associated with use of cell phones or computers. Practitioner summary: We investigated the possible relation between neck symptoms and use of computers/cell phones. We found that persons, who very often had symptoms in the neck, had also other symptoms very often (e.g. exhaustion at work). Their use of information and communication technology (e.g. computers) can associate with their symptoms.
 
Article
A dynamic biomechanical human model is presented which allows the quantification of mechanical parameters such as torque, compressive and shear forces, and pressure at the lumbar intervertebral discs. The human model comprises a total of 19 body segments. Various trunk flexions can be analysed due to the provision of 5 joints at the level of the 5 lumbar intervertebral discs. The influence of intraabdominal pressure on spinal load is considered. The inclusion of the influences of gravity and inertia permits the analysis of both static body postures and dynamic body movements. Since the model is 3-dimensional, the lumbar stress can be calculated during both symmetrical tasks in the median sagittal plane as well as during non-symmetrical ones. The influences on spinal stress of trunk inclination and the position of an external load relative to the body are quantified for various load weights up to 50 kg. The torque at the lumbo-sacral joint L5-S1 lies, dependent on posture and load lever-arm, within the range between 0 and 500 Nm; the compressive force on L5-S1 lies within the range between 0.4 and 10 kN, and the shear force at L5-S1 between 0.2 and 0.9 kN. The influences of lift velocity and jerky movement on lumbar stress are quantified. Simulated humpback and hollow-back postures are studied. The compressive forces at the 5 lumbar intervertebral discs are compared. The validity of the model is examined by comparing the model calculations with the intradiscal pressure measurements taken from the literature. Strength tests on lumbar intervertebral discs and vertebrae are collated from the literature in order to assess the lumbar stress during load lifting. The lumbar ultimate compression strength varies within a wide range. The mean value for a total of 307 lumbar segments amounts to 4.4 kN, the standard deviation to 1.9 kN. In conclusion, lumbar compressive force values during lifting fall within the same range as the strength values for the human lumbar spine.
 
Article
Women at work throughout Britain, all members of the National Survey of Health and Development, were asked whether they were under nervous strain in their work. Data are presented for 826 women at work at age 26 years and 734 women at work at age 32 years. Two in every five women working full-time reported that they were under strain, this proportion being very similar to that for men in full-time work at the same age. Women in part-time work were much less likely to report strain. Strain at work was found to relate both to the level of work (jobs in higher social-group categories having a higher report of strain) and to the level of supervisory responsibility. Women reporting strain were also more likely to report problems with their sleep, frequent headaches, pain in the pit of the stomach and trouble with their back, but such reports seem more closely related to a prior susceptibility to anxiety than to the demands of the present job. It is concluded that, with the possible exception of pregnant women, it may not be helpful to consider women as a group of workers with particular problems in withstanding stress at work.
 
Article
The 1960s represents a key decade in the expansion of ergonomics within the UK. This paper reviews trends and developments that emerged out of the 1960s and compares these with ergonomics research and practice today. The focus in particular is on the expansion of ergonomics as a discipline within industry, as well as more specific topics, such as the emergence of areas of interest, for example, computers and technology, automation and systems ergonomics and consumer ergonomics. The account is illustrated with a detailed timeline of developments, a set of industrial case studies and the contents of important publications during the decade. A key aim of the paper is to provide the opportunity to reflect on the past and the implications this may have for future directions for ergonomics within the UK. The paper provides practitioners with an insight into the development of ergonomics in the UK during one of the most important decades of its history. This is especially relevant given the fact that in 2009 the Ergonomics Society celebrates its 60th anniversary.
 
Article
The aim of this study was to quantify the secular changes in body dimensions of Royal Australian Air Force aircrew. Following corrections for methodological differences, two samples (matched for age and overall body size) of male aircrew measured in 1971 (n = 220) and 2005 (n = 220) were compared across 13 absolute and proportional body dimensions. Changes in means were expressed as standardised effect sizes and changes in distributional characteristics were expressed as the ratio of coefficients of variation and as changes in skew. Small secular increases (standardised effects sizes >0.2) in age-matched aircrew were observed for mass, height, BMI, sitting height, buttock-knee length, waist girth, hip girth and waist:hip ratio, with a small decline observed for head girth. Changes in body dimensions were not independent of changes in overall body size (except for head girth) and were not always uniform across the distribution. These changes in body size have implications for ensuring correct human-machine and human-equipment fit. STATEMENT OF RELEVANCE: There have been small secular changes in body dimensions of RAAF aircrew between 1971 and 2005, although these secular changes have not always been uniform across the distribution. These secular changes in body dimensions have implications for ensuring correct human-machine and human-equipment fit and underscore the need for regular anthropometric surveys.
 
Article
For many years, computer scientists have been concerned with whether computers can think. Considerable thought, therefore, goes into designing 'thinking' computer systems and into wondering whether they really can think, or just pretend to. On the other hand, it is 'obvious' that humans can think, and therefore little thought has gone into the related question, 'Can humans think?' This paper explores the ergonomic implications of the affirmative answer. Computers get better treatment than humans, yet humans are more than machines. However, not only do designers seem to forget this, but they do not even treat users with the same respect as they would a machine.
 
Article
The aim of this research was to evaluate whether the asymmetry multiplier incorporated in the 1991 National Institute for Occupational Safety and Health lifting equation adequately controls the biomechanical spine loads during asymmetric lifting. Sixteen male subjects lifted a box from four initial locations varying in terms of the angular deviation from the mid-sagittal plane (0, 30, 60 and 90 degrees). From each location, boxes that weighed the recommended weight limit (RWL) and three times the RWL were lifted at two qualitatively defined lifting speeds. Ground reaction forces were combined with kinematic data in a linked-segment model to quantify the 3-D moments at the base of the spine (L5/S1) and the spine compression forces. The results show that the twisting and lateral bending moments increased with task asymmetry despite the lessening of the RWL (p<0.01). The flexion moment and the spine compression decreased with asymmetry, although at a slower rate than the RWL. When the dynamics were removed from the linked segment spine model to approximate the assumption of slow and smooth lifting, the estimated compression remained approximately 3400 N across all asymmetry conditions. Thus, the reduction in the RWL due to asymmetry multiplier appears appropriate and should not be changed, as been suggested by recent psychophysical studies.
 
Article
Working posture is an important determinant of musculoskeletal and vascular health. Knowledge of the context and type of postures is necessary in order to examine their associations with health-related outcomes. This study describes self-reported usual working postures in a population and their associations with other working conditions and demographic variables. The 1998 Quebec Health and Social Survey is a population-based survey of 11,986 private households in the province of Quebec. It contained a self-administered questionnaire, including an extensive occupational health section. The analyses in this study were limited to respondents with paid employment who had at least 6 months seniority in their current job, comprising 9,425 subjects. The overall prevalence of usual work in a standing posture is 58%; it is more common among men, workers under 25 years, those in the two lowest educational quintiles and those with incomes under 20,000 Canadian dollars. Only one person in six who works standing reports being able to sit at will. Women and men differ in the types of usual standing and sitting postures at work. Those who work standing and/or who work in more constrained postures are more likely to be exposed to other physical work demands, such as handling heavy loads, repetitive work, forceful exertion and low job decision latitude. The association between decision latitude and constrained postures is an important link between psychosocial and physical stressors in the workplace. In epidemiological studies, exposure covariation and interactions should be considered in the generation and interpretation of the associations between work postures and musculoskeletal disorders.
 
Article
To stay relevant and applicable in a rapidly changing world, ergonomics must meet several challenges. The paper explores these challenges and how the profession might respond. It is proposed that there are opportunities, and a need, to embrace empathy as a legitimate and useful tool. Empathy has value in three main areas. In research we can broaden our understanding of people and situations, learning 'why' as well as 'how and what' people do. Second, by identifying with the emotional as well as intellectual concerns of sponsors and colleagues from other professions, we inspire trust and confidence, adding value to our collective efforts in collaborative work. Third, through methods such as role-playing and story telling, empathy is a powerful tool for getting ergonomics issues across to implementers and influencing outcomes. Care is needed to balance empathy with systematic observation in the tradition of the scientific method; the power of empathy is in combining it with objective methods to make full use of our abilities as human scientists.
 
Article
Developments in the Society are outlined since the early history was described by Edholm and Murrell. Major changes in the Society's operation and the context in which these changes took place are given. The changes in research directions, growth in educational facilities for professional education and the ever widening areas for the application of ergonomics are discussed. The consequences of these developments for the expansion of a recognition of the contribution of ergonomics, and the position of professionals in the international scene are touched upon.
 
Examples of work outcomes.
Article
Healthcare practitioners, patient safety leaders, educators and researchers increasingly recognise the value of human factors/ergonomics and make use of the discipline's person-centred models of sociotechnical systems. This paper first reviews one of the most widely used healthcare human factors systems models, the Systems Engineering Initiative for Patient Safety (SEIPS) model, and then introduces an extended model, 'SEIPS 2.0'. SEIPS 2.0 incorporates three novel concepts into the original model: configuration, engagement and adaptation. The concept of configuration highlights the dynamic, hierarchical and interactive properties of sociotechnical systems, making it possible to depict how health-related performance is shaped at 'a moment in time'. Engagement conveys that various individuals and teams can perform health-related activities separately and collaboratively. Engaged individuals often include patients, family caregivers and other non-professionals. Adaptation is introduced as a feedback mechanism that explains how dynamic systems evolve in planned and unplanned ways. Key implications and future directions for human factors research in healthcare are discussed.
 
Article
Usability testing is a widely used technique to evaluate user performance and acceptance of products and systems. It was introduced in the late 1980s and rose to popularity in the past decade. This paper provides a view of the current status of usability testing as a method and describes how it will be used in the 21st century. Although usability testing may not be the most efficient technique for discovery of usability problems, it is a reliable way to estimate quantitatively users' performance and subjective satisfaction with products. Four major trends in usability testing include: common reporting formats and methods for industry; Internet application and website testing; testing of mobile, handheld devices; and testing in more naturalistic environments such as simulated homes and classrooms. In the 21st century, 'quick and clean' usability testing methods are needed to provide valid and reliable data on how well people use products and systems, and how they like using them.
 
Article
The Nordic Ergonomic Society was founded more than 30 years ago to represent Sweden, Finland, Norway and Denmark. Recently Iceland has also been included. The Nordic Ergonomics Society has, to a large extent, traditionally been oriented towards work in the area of physiology, and a large number of its members have backgrounds within such areas as work physiology, physiotherapy and rehabilitation. However, from its inception the society has had members who are experienced within, such fields as work psychology, design, engineering and occupational health and safety. Over the last decade we have also had new members from such areas as work sociology, organizational psychology, leadership, training, information technology and cybernetics. Members have been concerned mainly with the application and practice of ergonomics. The number of members involved in research has also increased over the years. The principal areas of application for such research have been within industry and government.
 
Flow chart consisting of four steps to assess the risk of manual lifting to prevent work-related low back pain (NIOSH: National Institute for Occupational Safety and Health lifting equation, MAC = Manual handling Assessment Charts-tool).  
Search terms for systematic reviews regarding the clinimetric quality of assessments methods for workload due to lifting
Article
Free full text (limited number): http://www.tandfonline.com/eprint/z9P3JQTVazVpjVrDUyuR/full Non-specific low back pain (nLBP) is the second most important reason for sick leave in the Netherlands, and more than 50% of the workers on sick leave attribute these complaints to their work. To stimulate recognition and prevention, an occupational disease (OD) registration-guideline was implemented for the assessment of the work-relatedness of nLBP in the Netherlands in 2005. The aim of this study is to present the annual incidence of nLBP as an OD and specifically for whole-body vibration (WBV) including patient characteristics such as age, sick leave and actions initiated by the occupational physician (OP). The data were retrieved from the National Dutch Register for 2005-2012. Each year about 118 OPs reported 509 cases (SD 139) of nLBP as an OD in a Dutch working population of 7.5 million workers (8% of all annual reported ODs). Less than 1% of these cases were attributed to WBV: 94% were men, 45% were between 51 and 60 years and 35% were on sick leave for more than 2 weeks. Most initiated actions were ergonomic interventions (35%).
 
Article
The relationship between research and practice in ergonomics and human factors has rarely been addressed in the literature. This presents specific problems for researchers when seeking to relate their work to the research community. Equally, practitioners are often frustrated by the lack of appropriate research to meet their needs. This paper seeks to identify current drivers for ergonomics research along with an analysis of how these are changing. Specifically, the use of bibliometric data to assess research output and its impact on a multi-disciplinary subject such as ergonomics is examined. Areas where action may be required to stimulate better research and improved practice are proposed. These include a greater role for the practitioner in completing the circle of knowledge and improving the evidence base for practice with, in particular, practitioners becoming more active in determining research priorities. It is concluded that combined effort is needed by researcher and practitioner communities to enable and promote a more effective understanding of the true impact of ergonomics across industry and society. STATEMENT OF RELEVANCE: The relationship between ergonomics research and practice is examined. Research 'drivers' are identified, including the influence of bibliometric data. Implications for researchers and practitioners are discussed. The role of practitioners in completing the circle of knowledge and improving the ergonomics evidence base is stressed, as is the need to promote the impact of ergonomics across society.
 
Article
Physiological and anthropometric measurements were taken on 21 members of an under-21 international squad of mean age 18.9 years. The aims of the investigation were (i) to examine the physiological status of players according to playing unit; and (ii) to quantify the changes arising from a four-month training programme. Maximal/peak oxygen uptake was assessed using an incremental test to exhaustion during treadmill running. Anaerobic performance was measured using the 30s Wingate test. Significant differences occurred between playing units in height (p < 0.001), body mass and FVC (p < 0.05), but not in skinfolds or any of the expressions of aerobic or anaerobic performance (p > 0.05). As a consequence of the training programme significant differences were evident in height (169.7 v 170.1 cm, p < 0.01), body mass (62 v 64 kg, p < 0.05), FVC (4.3 v 4.51, p < 0.01), and anaerobic performance (p < 0.01). Increases in VO2 max (3.3 v 3.51.min-1) were not significant (p > 0.05). Standard deviation scores illustrated that aerobic and anaerobic performances were of roughly the same magnitude before training (-0.35 v -0.29, p > 0.05), but that after training the dominant performance was anaerobic (+0.11 v +1.48, p < 0.01).
 
Article
The effects of variation in dry-bulb temperature between 2L°C anil 35°C on tho physiologiea) responses to a 12-minute progressive submaximal exorcise tost have been examined in four healthy men partially acclimated to heat. On average, cardiac frequency and minute ventilation at standard oxygen uptake increased by 14% (r+0 85; /;<0 001) mid 0-4% (r+0*4t>; p<0-001) rospectively for each degree rise in dry-bulb temperature. The increase in exercise cardiac frequency with each degree rise in mean akin temperature averaged r>-1 %. A regression relationship is prosented which permits adjustment of the cardiac frequency at standard oxygen uptake to either a standard dry-bulb tomperature or mean skin temperature, its use and limitations are illustrated using data collccted during studios which formed part of tho U.K. contribution to the international Biological Programme.
 
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Functional stability limits (FSLs) are the percentage of the base of support that individuals are willing to extend their centre of pressure. The objective of this study was to provide construct validation of FSLs as a measure of balance by comparing FSLs across ages and with clinical balance measures. A total of 52 participants volunteered. FSLs significantly decreased with age (p < 0.004). Correlations between FSLs and age (-0.56 < R < -0.73), multi-directional reach test (0.35 < R < 0.75) and anteroposterior and mediolateral centre of pressure excursions during static stance (-0.29 < R < -0.72) were generally moderate to good. Cronbach's alpha (0.75) indicated that these measures were internally consistent, i.e. measuring similar aspects of the balance construct. FSLs appear to be valid indicators of balance ability. They may be used in posture prediction models to determine when a step is required when reaching or lifting objects and in biomechanical models as a means of incorporating stability constraints.
 
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The study investigated time-of-day effects on task performance in shift workers in different tasks (reaction time, discrimination, probe recognition, free recall), by varying task-specific features. On each of six recordings, each programmed on a different day and in a randomised order, operators rated alertness and performed different tasks. Self-rated alertness varied according to a typical diurnal trend. Time of day also affected reaction time (slower responses at 03:00 hours), discrimination performance (lower accuracy at 03:00 hours in the most difficult condition) and recall (superior recall at 07:00 and 11:00 hours following deeper processing at encoding). The data demonstrated time-of-day effects on cognitive processes also involved in many real-job activities, despite the lack of control for a number of exogenous factors known to interfere with performance in work settings. Since in the cognitively more loaded tasks, time-of-day effects depended on task conditions, the findings are of operational concern in shift-work situations involving differential task requirements. In a real-job setting, performance variations were observed according to time of day and task requirements in a set of cognitively more or less demanding tasks. Task-specific research across the 24-h day enables a better understanding of operators' tasks and the development of supporting technology.
 
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Unlabelled: The aim of this study was to evaluate the feasibility of methods for objective 24-h sampling of physical activity among cleaners. Twenty cleaners participated in three 24-h measurements. Amount of steps, heart rate (HR), cardio-respiratory fitness, body mass index (BMI) and blood pressure were measured. The methods were feasible for the objective 24-h sampling of physical activity and cardio-respiratory fitness among cleaners. Measurements showed that the cleaners walked 20,198 ± 4,627 steps per day. During working hours, the average cardio-respiratory load was 25 ± 6% of heart rate reserve (HRR). The cleaners had a low estimated cardio-respiratory fitness (34 mlO2/kg/min), a high BMI (50%, >25 kg/m(2)) and blood pressure (50%, >120/>80 mmHg). The high amount of steps, the relatively high cardiovascular load at work and low cardio-respiratory fitness illustrate the need for further investigation of the relationship between physical activity at work and in leisure, and cardiovascular health in this population. Practitioner summary: This study evaluated the feasibility of methods for objective 24-h sampling of physical activity among cleaners; the methods used were found to be feasible. The cleaners had a high cardiovascular load at work and low cardio-respiratory fitness, suggesting that there is a need for further investigations.
 
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The current study examined the frequency with which shorter than 24-h work/rest cycles occur in locomotive engineer work schedules, and what effects these work/rest cycles had on sleep quantity and sleep quality. The results indicated that shorter than 24-h work/rest cycles occurred in 33.6% of the work days reported by 198 locomotive engineers. In addition, the shorter than 24-h work/rest cycles occurred more frequently in work schedules that created an on-call work system, such as road pool turn and extra board assignments, than in work schedules that used more predictable or regular work times, such as regular road assignments and yard/local work. As would be expected, when engineers worked shorter than 24-h work/rest cycles, they reported less sleep and poorer sleep than under the longer than 24-h work/rest cycles. Similarly, on-call work assignments resulted in less sleep and poorer sleep than regular work assignments. These results indicate that specific aspects of the work schedules used in railroad operations, particularly on-call operations that result in shorter than 24-h work/rest cycles, can lead to increased sleep-related problems. Although the North American railroad industry is making significant changes in on-call operations to minimize sleep-related problems from on-call schedules, better fatigue-related models validated within the railroad industry are needed.
 
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The maximal aerobic performance ([Vdot]O2max) and energy cost of running at various speeds of two ultra-distance athletes were measured in the laboratory on a motor driven treadmill and the results related to observations made during a 24 h race. The athletes finished 1st and 2nd in the event and covered distances of 251·46 km and 234·56 km respectively during the 24 h period. From the measurements in the laboratory it was calculated that the average speeds sustained by the athletes during the competition were equivalent to an O2 cost of 36·4 ml kg min and 35·3 ml kg min which represented approximately 50% of their [Vdot]O2max. During the race the winner expended an estimated 77,829 kJ (18.595 kcal) which is three times the highest recorded value in the most severe industrial work. By the nature of the activity this figure must be regarded as at or near the upper limit of sustainable energy expenditure by man during a complete uninterrupted 24 h circadian cycle.
 
Average daily energy expenditure over the two 10-d training periods. DNF ¼ did not finish. 
Average daily physical activity counts during weeks 1-2, 5, 9, 15 and 19-20 of training. The horizontal lines represent the Monday-Friday 5-d average for each of the five monitoring periods. Values are means (SE). 
Average daily % heart rate reserve (HRR) during weeks 1-2, 5, 9, 15 and 19-20 of training. The horizontal lines represent the Monday-Friday 5-d averages. Values are means (SE). 
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This study assessed the physical demands of the 24-week Combined Infantryman's Course (CIC) for Parachute Regiment (Para) recruits and developed physical selection standards for applicants. Fifty recruits were monitored over five separate periods (35 d in total during weeks 1-2, 5, 9, 15 and 19-20). Energy expenditure (doubly labelled water), physical activity (accelerometry) and cardiovascular strain (% heart rate reserve) were measured. There was no overall progression in both the levels of physiological stress (physical activity counts and energy expenditure) and resultant cardiovascular strain during the first nine weeks of training. Applicants' 2.4 km run time and static lift strength measured at selection predicted 10 mile loaded march performance at the end of CIC Para. The introduction of job-related selection procedures and a more progressive approach to training has reduced the incidence of medical discharge from 14.4% to 5.1% and increased overall pass rates from 43% to 58%.
 
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Most tools, utensils, office equipment, home appliances, clothes, medical instruments, sporting goods, weapons and public facilities are made for people who are right-handed. Many left-handed people have to endure a certain amount of inconvenience or difficulty in carrying out daily activities in such an environment. In this study, 2437 Korean male and female participants were randomly selected to collect a variety of data on hand dominance and hand preference when handling diverse products and facilities. Their responses in a questionnaire survey revealed that 5.8% were left-handed and 7.9% were ambidextrous. The younger participants who were from teens to 39 years reported higher percentages of left-handedness than those over 40 years, with those in their thirties reporting the highest proportion of left-handedness (7.3-7.6%) for both men and women. A slightly higher percentage of the male participants (5.9%) said that they were left-handed than did the female participants (5.6%). However, the percentage who were ambidextrous varied with age group, but overall there was a higher percentage of women (8.3%) than of men (7.6%). The analysis of hand use behaviour revealed that the right-handed and ambidextrous people had a tendency to use their right hands more for actions that required accuracy than those that required force. The left-handed people had a strong tendency to use their left hands more often when making a forceful action than for one that required accuracy. Derived from these results, the conclusion is that, depending on their hand dominance, people seem to use their hands differently when they handle objects or use facilities, which should be considered in the design of hand-controlled devices. Depending on which hand is the dominant one, people seem to use their hands differently when they handle objects or use facilities. The left-handed tend to use their left hands more with force-required motions than with accuracy-required motions, while ambidextrous and right-handed people use their right hands more with accuracy-required motions than with force-required motions. Designers of products and facilities will find the results of this study useful for developing hand-controlled devices and systems.
 
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This paper illustrates the viewpoint of a group of Italian research workers who have been directly involved in providing criteria and guidelines for application of EC Directive 90/269, Manual handling of loads. The problems posed by application of the Directive in Italy and which are mainly related to exposure assessment, health surveillance and risk management (work and workplace redesign) are thoroughly examined. Major questions still to be solved include defining methods for assessment of multiple and complex load handling tasks, identifying data sources on 'health effect' trends as investigated in a working population with low exposure or in the general population in order to fix action levels, and setting up a data bank of technical and organizational solutions and products accessible to experts and users.
 
Top-cited authors
Neville A Stanton
  • University of Southampton
Pascale Carayon
  • University of Wisconsin–Madison
Peter A Hancock
  • University of Central Florida
Paul Matthew Salmon
  • University of the Sunshine Coast
Jan Dul
  • Rotterdam School of Management, Erasmus Universiteit Rotterdam