Results in Applied Ergonomics: 10,633
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Applied Ergonomics, Volume 67, pp 83-90; https://doi.org/10.1016/j.apergo.2017.09.013
A timely and accurate acquisition of the information provided by variable message signs (VMS) can be crucial while driving. In the current study, we assess the difficulties of adults with dyslexia acquiring the information shown in VMS and provide evidence to discuss the controversial use of pictograms as potential countermeasures. Twenty-two adults with dyslexia and 22 matched controls completed a simulated driving session. The legibility of 12 VMS was assessed, including six text messages (e.g. “ACCIDENT”) and six single pictograms (e.g. the icon for “accident ahead”). On average, participants with dyslexia started reading text messages when they were closer to the VMS. In addition, while approaching text VMS, they dedicated more gazes and manifested worse control of speed. Regarding pictogram VMS, we observed no differences in response distance, accuracy, response duration, or number of gazes. To sum up, the evidence provided reveals that adults with dyslexia, despite potential compensation effects, may still find difficulties reading text messages in VMS (shorter legibility distances, longer reading times, and increased cognitive effort), whereas we found no such differences in the recognition of pictograms (only some difficulties keeping a steady speed). Research on inclusive measures to improve reading in low-skilled or dyslexic drivers must be encouraged.
Applied Ergonomics, Volume 67, pp 71-82; https://doi.org/10.1016/j.apergo.2017.09.008
A polar supply and research vessel is pre-disposed to wave slamming which has caused complaints among crew and researchers regarding interference with sleep, equipment use and research activities. The present work undertook to survey passenger claims of sleep interference, disturbed motor tasks and equipment damage as a result of wave slamming during normal operations of this vessel. The hypothesis was investigated that whole-body vibration metrics from ISO 2631-1 are potentially suitable for the prediction of human slamming complaints. Full-scale acceleration measurements were performed and wave slamming events were subsequently identified from the human weighted acceleration time histories. A daily diary survey was also conducted to gather the human response. The vibration caused by wave slamming was found to be strongly correlated with sleep disturbances and activity interference. Sleep and equipment use were found to be the most affected parameters by slamming. Daily vibration dose values were determined by accumulating the vibration as a result of slamming over 24 h periods. This metric accounted for increased magnitudes and frequency of slamming incidents and proved to be the best metric to represent human responses to slamming vibration. The greatest percentage of activities affected by slamming related to sleep regardless of daily cumulative VDV magnitude. More than 50% of the recorded responses related to sleep when the daily cumulative VDV ranged between 8.0 m/s 1.75 –10.0 m/s 1.75 . The peak vertical vibration levels recorded on the vessel reach magnitudes which are associated with sleep disturbance in environments where acoustic noise is present.
Applied Ergonomics, Volume 67, pp 50-60; https://doi.org/10.1016/j.apergo.2017.08.014
Examinations of interruptions in healthcare often focus on a single clinical discipline, and solutions are targeted accordingly. This approach does not take into account the inter-disciplinary dependencies and other sociotechnical aspects that make up the healthcare work system, and suggested solutions may not meet the needs of all stakeholders. In this article a sociotechnical systems perspective is used to uncover the interdependencies between 16 unique work roles that result in interruptions in an intensive care unit (ICU). By applying social network analysis techniques to data collected using the Dual Perspectives Method, we identified targeted systems-based interventions that may reduce unnecessary interruptions while avoiding unintended consequences that impose additional burden on ICU staff. The rich insights gained into the interruptive communication patterns in the ICU work system stand in contrast to findings that would have otherwise been obtained by focusing only on a single clinical discipline or a single perspective.
Applied Ergonomics, Volume 67, pp 39-49; https://doi.org/10.1016/j.apergo.2017.09.004
The effect of spatial compatibility for various display-control configurations on human performance was studied with a dual-task paradigm using a tracking task and a discrete response task. Degradation of performance on both tasks within the visual modality was observed and was considered to be most likely due to resource competition resulting from simultaneous task operation. It was found that the more complicated the mapping for the discrete spatial compatibility response task, the more severe the interference with the tracking task. Although performance on both the tracking and spatial response tasks was impaired, the magnitude of impairment was not as great as expected, implying that focal and ambient vision required for the tracking task and spatial task, respectively, might be deployed, at least partly, from separate resources. Participants here seemed to successfully use focal vision for tracking and ambient vision for identifying signal lights concurrently, reducing the expected keen competition for visual resources.
Applied Ergonomics, Volume 66; https://doi.org/10.1016/s0003-6870(17)30211-9
Applied Ergonomics, Volume 67, pp 26-38; https://doi.org/10.1016/j.apergo.2017.09.006
Several crash reports have identified in-vehicle distraction to be a primary cause of emergency vehicle crashes especially in law enforcement. Furthermore, studies have found that mobile computer terminals (MCTs) are the most frequently used in-vehicle technology for police officers. Twenty police officers participated in a driving simulator-based assessment of visual behavior, performance, workload and situation awareness with current and enhanced MCT interface designs. In general, results revealed MCT use while driving to decrease officer visual attention to the roadway, but usability improvements can reduce the level of visual distraction and secondary-task completion time. Results also suggest that use of MCTs while driving significantly reduces perceived level of driving environment awareness for police officers and increases cognitive workload. These findings may be useful for MCT manufacturers in improving interface designs to increase police officer and civilian safety.
Applied Ergonomics, Volume 67, pp 9-25; https://doi.org/10.1016/j.apergo.2017.09.005
Wheelchair rugby is a sport that has been gaining popularity with athletes with disabilities. However, as it is relatively new and not played by the masses, market specific sports-wear is not available for this sport, which impacts directly on performance and clothing satisfaction of the athletes. Therefore, the main objective of this research was to identify the problems that wheelchair rugby players face with the sports-wear they use for playing the game. The data was collected using a focus group and a questionnaire with 61 wheelchair rugby players in the United Kingdom. Based on their suggestions, on the team expertise, and on the literature, a set of design recommendations was proposed for the upper body garments (tops), lower body garments (bottoms), and gloves. The results demonstrated that the gloves currently available negatively impact on players’ ability to participate with satisfactory levels of protection and comfort. Moreover, tops and bottoms also present issues, mainly in the fit and ability to regulate the core body temperature. Hence, the recommendations proposed can provide designers with key information on the specific sports-wear requirements and allow them to design and develop products that can satisfy real needs of specific end-users. This paper intends to raise awareness of the needs of sports-wear for those playing wheelchair rugby and promote the inclusivity of athletes with disabilities.
Applied Ergonomics, Volume 67, pp 1-8; https://doi.org/10.1016/j.apergo.2017.09.002
We sought to evaluate potential mediators of the relationship between heat exposure and traumatic injuries in outdoor agricultural workers. Linear mixed models were used to estimate associations between maximum work-shift Wet Bulb Globe Temperature (WBGT max ) and post-shift vigilance (reaction time) and postural sway (total path length) in a cross-sectional sample of 46 Washington State tree fruit harvesters in August–September 2015. The mean (SD) WBGT max was 27.4 (3.2)°C in August and 21.2 (2.0)°C in September. The mean pre-work-shift participant urine specific gravity indicated minimal dehydration. Twenty-four percent of participants exhibited possible excessive sleepiness. There was no association between WBGT max and post-shift reaction time or total path length. Heat exposure was not associated with impaired vigilance or balance in this study, in which the overall mean (SD) WBGT max was 25.9 (4.2)°C. However, the study identified opportunities to ensure adequate pre-work-shift hydration and to optimize sleep and work-shift timing in order to reduce occupational injury and heat-related illness risk.
Applied Ergonomics, Volume 66, pp 172-176; https://doi.org/10.1016/j.apergo.2017.09.001
This study aimed to assess whether modifying the pitch of a 75° ladder ergometer to vertical had a cardiorespiratory or psychophysical effect on climbing. Nine male participants climbed a ladder ergometer at 75° and subsequently at 90°, adjusted for an equivalent vertical climb rate, completing three climbing bouts at different vertical speeds. One participant dropped out being unable to complete the climb under the 90° condition. Each was monitored for heart rate (HR), V˙O2 and rating of perceived exertion (RPE). Results showed vertical climbing induced higher V˙O2 (mean increase 17.3%), higher HR (mean increase 15.8%), and higher RPE at all speeds and that moving from 75°to vertical exacerbates the effect of speed on the cardiorespiratory response to climbing. This may be explained by increased force production required to maintain balance in a vertical climbing position when the body's centre of mass is not above the feet.
Applied Ergonomics, Volume 66, pp 161-171; https://doi.org/10.1016/j.apergo.2017.08.013
Crash reports from various states in the U.S. have shown high numbers of emergency vehicle crashes, especially in law enforcement situations. This study identified the perceived importance and frequency of police mobile computing terminal (MCT) tasks, quantified the demands of different tasks using a cognitive performance modeling methodology, identified usability violations of current MCT interface designs, and formulated design recommendations for an enhanced interface. Results revealed that "access call notes", "plate number check" and "find location on map" are the most important and frequently performed tasks for officers. "Reading plate information" was also found to be the most visually and cognitively demanding task-method. Usability principles of "using simple and natural dialog" and "minimizing user memory load" were violated by the current MCT interface design. The enhanced design showed potential for reducing cognitive demands and task completion time. Findings should be further validated using a driving simulation study.
Applied Ergonomics, Volume 66, pp 151-160; https://doi.org/10.1016/j.apergo.2017.08.011
This study investigated the acute effects of changing the work pace and implementing two pause types during an assembly task. Eighteen healthy women performed a simulated task in four different conditions: 1) slow or 2) fast work pace with 3) passive or 4) active pauses every two minutes. The root mean square (RMS) and exposure variation analysis (EVA) from the trapezius and serratus anterior muscles, as well as the rate of perceived exertion (RPE) from the neck-shoulder region, were observed. Decreased RMS and RPE as well as more variable muscle activity (EVA) were observed in the slow work pace compared with the fast one. The pause types had a limited effect, but active pauses resulted in increased RMS of the clavicular trapezius. The findings revealed the importance of work pace in the reduction of perceived exertion and promotion of variation in muscle activation during assembly tasks. However, the pause types had no important effect on the evaluated outcomes.
Applied Ergonomics, Volume 66, pp 139-150; https://doi.org/10.1016/j.apergo.2017.08.006
Safety leadership is an important factor in supporting safe performance in the workplace. The present case study examined the role of safety leadership during the Bingham Canyon Mine high-wall failure, a significant mining incident in which no fatalities or injuries were incurred. The Critical Decision Method (CDM) was used in conjunction with a self-reporting approach to examine safety leadership in terms of decisions, behaviours and actions that contributed to the incidents' safe outcome. Mapping the analysis onto Rasmussen's Risk Management Framework (Rasmussen, 1997), the findings demonstrate clear links between safety leadership decisions, and emergent behaviours and actions across the work system. Communication and engagement based decisions featured most prominently, and were linked to different leadership practices across the work system. Further, a core sub-set of CDM decision elements were linked to the open flow and exchange of information across the work system, which was critical to supporting the safe outcome. The findings provide practical implications for the development of safety leadership capability to support safety within the mining industry.
Applied Ergonomics, Volume 66, pp 179-181; https://doi.org/10.1016/j.apergo.2017.08.012
Applied Ergonomics, Volume 66, pp 182-192; https://doi.org/10.1016/j.apergo.2017.08.010
Highly automated driving will change driver's behavioural patterns. Traditional methods used for assessing manual driving will only be applicable for the parts of human-automation interaction where the driver intervenes such as in hand-over and take-over situations. Therefore, driver behaviour assessment will need to adapt to the new driving scenarios. This paper aims at simplifying the process of selecting appropriate assessment methods. Thirty-five papers were reviewed to examine potential and relevant methods. The review showed that many studies still relies on traditional driving assessment methods. A new method, the Failure-GAM 2 E model, with purpose to aid assessment selection when planning a study, is proposed and exemplified in the paper. Failure-GAM 2 E includes a systematic step-by-step procedure defining the situation, failures (Failure), goals (G), actions (A), subjective methods (M), objective methods (M) and equipment (E). The use of Failure-GAM 2 E in a study example resulted in a well-reasoned assessment plan, a new way of measuring trust through feet movements and a proposed Optimal Risk Management Model. Failure-GAM 2 E and the Optimal Risk Management Model are believed to support the planning process for research studies in the field of human-automation interaction.
Applied Ergonomics, Volume 66, pp 105-120; https://doi.org/10.1016/j.apergo.2017.07.015
The paper describes an iterative development process used to understand the suitability of different inclusive design evaluation tools applied into design practices. At the end of this process, a tool named Inclusive Design Advisor was developed, combining data related to design features of small appliances with ergonomic task demands, anthropometric data and exclusion data. When auditing a new design the tool examines the exclusion that each design feature can cause, followed by objective recommendations directly related to its features. Interactively, it allows designers or clients to balance design changes with the exclusion caused. It presents the type of information that enables designers and clients to discuss user needs and make more inclusive design decisions.
Applied Ergonomics, Volume 66, pp 82-88; https://doi.org/10.1016/j.apergo.2017.08.001
The systems approach is increasingly used as a framework within which to examine safety climate. Utilizing a macroergonomics approach to design work systems can help identify aspects of human-technology-organization interfaces that impact workers' perceptions of safety, both positively and negatively. Such an approach also supplements traditional uses of safety climate as a leading indicator of safety and helps expand research toward an approach that can determine problems impacting safety. The purpose of this study was to develop a methodology that extends safety climate beyond just an overall score by using the framework of macroergonomics to examine the entire system in a more comprehensive manner. The proposed methodology can be used as a way to identify gaps in the specific work system, and this information can be used to design interventions to change the safety climate, and ultimately the culture, of an organization in order to reduce negative safety outcomes.
Applied Ergonomics, Volume 66, pp 89-97; https://doi.org/10.1016/j.apergo.2017.08.008
The unique geographical location of Hainan makes its climate characteristics different from inland areas in China. The thermal comfort of Hainan also owes its uniqueness to its tropical island climate. In the past decades, there have been very few studies on thermal comfort of the residents in tropical island areas in China. A thermal environment test for different types of buildings in Hainan and a thermal comfort field investigation of 1944 subjects were conducted over a period of about two months. The results of the survey data show that a high humidity environment did not have a significant impact on human comfort. The neutral temperature for the residents in tropical island areas was 26.1 °C, and the acceptable temperature range of thermal comfort was from 23.1 °C to 29.1 °C. Residents living in tropical island areas showed higher heat resistance capacity, but lower cold tolerance than predicted. The neutral temperature for females (26.3 °C) was higher than for males (25.8 °C). Additionally, females were more sensitive to air temperature than males. The research conclusions can play a guiding role in the thermal environment design of green buildings in Hainan Province.
Applied Ergonomics, Volume 66, pp 98-104; https://doi.org/10.1016/j.apergo.2017.08.009
Dissatisfaction with work boot design is common in the mining industry. Many underground coal miners believe their work boots contribute to the high incidence of lower limb injuries they experience. Despite this, the most recent research to examine underground coal mining work boot satisfaction was conducted over a decade ago. This present study aimed to address this gap in the literature by assessing current mining work boot satisfaction in relation to the work-related requirements for underground coal mining. 358 underground coal miners (355 men; mean age = 39.1 ± 10.7 years) completed a 54-question survey regarding their job details, work footwear habits, foot problems, lower limb and lower back pain history, and work footwear fit and comfort. Results revealed that underground coal miners were not satisfied with their current mining work boots. This was evident in the high incidence of reported foot problems (55.3%), lower back pain (44.5%), knee pain (21.5%), ankle pain (24.9%) and foot pain (42.3%). Over half of the underground coal miners surveyed believed their work boots contributed to their lower limb pain and reported their work boots were uncomfortable. Different working roles and environments resulted in differences in the incidence of foot problems, lower limb pain and comfort scores, confirming that one boot design cannot meet all the work-related requirements of underground coal mining. Further research examining the interaction of a variety of boot designs across the different underground surfaces and the different tasks miners perform is paramount to identify key boot design features that affect the way underground coal miners perform. Enhanced work boot design could improve worker comfort and productivity by reducing the high rates of reported foot problems and pain amongst underground coal miners.
Applied Ergonomics, Volume 66, pp 52-63; https://doi.org/10.1016/j.apergo.2017.08.003
Stair ascending performance is critical during evacuation from buildings and underground infrastructures. Healthy subjects performed self-paced ascent in three settings: 13 floor building, 31 floor building, 33 m stationary subway escalator. To investigate leg muscle and cardiorespiratory capacities and how they constrain performance, oxygen uptake (VO2), heart rate (HR) and ascending speed were measured in all three; electromyography (EMG) in the first two. The VO2 and HR ranged from 89 to 96% of the maximum capacity reported in the literature. The average highest VO2 and HR ranged from 39 to 41 mL·kg(-1)·min(-1) and 162 to 174 b·min(-1), respectively. The subjects were able to sustain their initial preferred maximum pace for a short duration, while the average step rate was 92-95 steps·min(-1). In average, VO2 reached relatively stable values at ≈37 mL·kg(-1)·min(-1). EMG amplitudes decreased significantly and frequencies were unchanged. Speed reductions indicate that climbing capacity declined in the process of fatigue development. In the two buildings, the reduction of muscle power allowed the subjects to extend their tolerance and complete ascents in the 48 m and 109 m high stairways in 2.9 and 7.8 min, respectively. Muscle activity interpretation squares were developed and proved advantageous to observe fatigue and recovery over time.
Applied Ergonomics, Volume 66, pp 70-81; https://doi.org/10.1016/j.apergo.2017.08.002
The purpose of this study was to develop a methodology that extends safety climate beyond an overall score by using the framework of macroergonomics to examine the entire system in a more comprehensive manner. The study is discussed in two papers: one paper describes the study methodology in detail (Murphy, Robertson, Huang, Jeffries, & Dainoff, in press), and the current paper describes the results of the study. Multiple methods were combined to create a systems approach, and those methods include the critical incident technique, contextual inquiries with functional role diagrams, and affinity mapping. Key informants in the trucking industry identified 19 themes that affect safety. The themes ranged from balancing work and family/personal time, the company's policy vs. practice, respecting the job of the driver, and active listening and meaningful feedback. The most prominent themes were related to the workers and their activities; the internal environment, including psychosocial job design elements; and organizational design. Such information can be used to design interventions to change the safety climate of an organization in order to reduce negative safety outcomes.
Applied Ergonomics, Volume 66, pp 121-138; https://doi.org/10.1016/j.apergo.2017.08.005
The vibration isolation performances of vibration reducing (VR) gloves are invariably assessed in terms of power tools' handle vibration transmission to the palm of the hand using the method described in ISO 10819 (2013), while the nature of vibration transmitted to the fingers is ignored. Moreover, the VR gloves with relatively low stiffness viscoelastic materials affect the grip strength in an adverse manner. This study is aimed at performance assessments of 12 different VR gloves on the basis of handle vibration transmission to the palm and the fingers of the gloved hand, together with reduction in the grip strength. The gloves included 3 different air bladder, 3 gel, 3 hybrid, and 2 gel-foam gloves in addition to a leather glove. Two Velcro finger adapters, each instrumented with a three-axis accelerometer, were used to measure vibration responses of the index and middle fingers near the mid-phalanges. Vibration transmitted to the palm was measured using the standardized palm adapter. The vibration transmissibility responses of the VR gloves were measured in the laboratory using the instrumented cylindrical handle, also described in the standard, mounted on a vibration exciter. A total of 12 healthy male subjects participated in the study. The instrumented handle was also used to measure grip strength of the subjects with and without the VR gloves. The results of the study showed that the VR gloves, with only a few exceptions, attenuate handle vibration transmitted to the fingers only in the 10-200 Hz and amplify middle finger vibration at frequencies exceeding 200 Hz. Many of the gloves, however, provided considerable reduction in vibration transmitted to the palm, especially at higher frequencies. These suggest that the characteristics of vibration transmitted to fingers differ considerably from those at the palm. Four of the test gloves satisfied the screening criteria of the ISO 10819 (2013) based on the palm vibration alone, even though these caused amplification of handle vibration at the fingers. The fingers' vibration transmission performance of gloves were further evaluated using a proposed finger frequency-weighting Wf apart from the standardized Wh-weighting. It is shown that the Wh weighting generally overestimates the VR glove effectiveness in limiting the fingers vibration in the high (H: 200-1250 Hz) frequency range. Both the weightings, however, revealed comparable performance of gloves in the mid (M: 25-200 Hz) frequency range. The VR gloves, with the exception of the leather glove, showed considerable reductions in the grip strength (27-41%), while the grip strength reduction was not correlated with the glove material thickness. It is suggested that effectiveness of VR gloves should be assessed considering the vibration transmission to both the palm and fingers of the hand together with the hand grip strength reduction.
Applied Ergonomics, Volume 66, pp 64-69; https://doi.org/10.1016/j.apergo.2017.08.007
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Applied Ergonomics, Volume 66, pp 41-51; https://doi.org/10.1016/j.apergo.2017.07.003
The research-practice gap has been highlighted as a barrier to effective practice in human factors and ergonomics (HFE). There is also evidence of a theory-research gap that may be limiting the scientific evidence base of HFE. The purpose of this study was to examine trends in journal publications, especially relating to the research-practice gap and the involvement of theory over time. A content analysis was conducted on 425 journal articles published in Human Factors, Ergonomics, and Applied Ergonomics from 1960 to 2010. Results showed evidence of growth in applied research with increasing collaborative research between research and industry, larger research teams, and more empirical research-especially on applied problems. While there has been a corresponding increase in the involvement of theory in HFE publications, around half of the publications failed to acknowledge theory. This calls into question whether the HFE discipline may be missing the benefits of theory to guide research and subsequent practice, and to enhance the development of new ideas.
Applied Ergonomics, Volume 66, pp 32-40; https://doi.org/10.1016/j.apergo.2017.08.004
Kinematics at heel strike instant (HSI) has been used to quantify slip severity. However, methods to identify HSI remain ambiguous and have not been evaluated under slippery conditions. A glass force plate was used to observe the contact interface between shoe and floor under slippery conditions. HSIs identified from the video captured beneath the force plate and from the force plate and kinematics were compared. The results showed that HSIs identified with the video were closer to those identified with the normal force threshold (NFT) (9.0 ms ± 5.5 ms) than were most of those identified with kinematics. Slips with a longer distance travelled between NFT HSI and video HSI had a larger heel horizontal velocity (>0.8 m/s) and a smaller foot angular velocity (<100deg/s) at the NFT instant, and were still part of the forward swing. The results show that improved methods are needed over NFT to identify HSI, especially under slippery conditions.
Applied Ergonomics, Volume 66, pp 177-178; https://doi.org/10.1016/j.apergo.2017.07.004
Applied Ergonomics, Volume 66, pp 18-31; https://doi.org/10.1016/j.apergo.2017.07.006
Trust in automation is a key determinant for the adoption of automated systems and their appropriate use. Therefore, it constitutes an essential research area for the introduction of automated vehicles to road traffic. In this study, we investigated the influence of trust promoting (Trust promoted group) and trust lowering (Trust lowered group) introductory information on reported trust, reliance behavior and take-over performance. Forty participants encountered three situations in a 17-min highway drive in a conditionally automated vehicle (SAE Level 3). Situation 1 and Situation 3 were non-critical situations where a take-over was optional. Situation 2 represented a critical situation where a take-over was necessary to avoid a collision. A non-driving-related task (NDRT) was presented between the situations to record the allocation of visual attention. Participants reporting a higher trust level spent less time looking at the road or instrument cluster and more time looking at the NDRT. The manipulation of introductory information resulted in medium differences in reported trust and influenced participants' reliance behavior. Participants of the Trust promoted group looked less at the road or instrument cluster and more at the NDRT. The odds of participants of the Trust promoted group to overrule the automated driving system in the non-critical situations were 3.65 times (Situation 1) to 5 times (Situation 3) higher. In Situation 2, the Trust promoted group's mean take-over time was extended by 1154 ms and the mean minimum time-to-collision was 933 ms shorter. Six participants from the Trust promoted group compared to no participant of the Trust lowered group collided with the obstacle. The results demonstrate that the individual trust level influences how much drivers monitor the environment while performing an NDRT. Introductory information influences this trust level, reliance on an automated driving system, and if a critical take-over situation can be successfully solved.
Applied Ergonomics, Volume 65; https://doi.org/10.1016/s0003-6870(17)30176-x
Applied Ergonomics, Volume 65, pp 398-409; https://doi.org/10.1016/j.apergo.2017.05.006
Psychological research into human factors frequently uses simulations to study the relationship between human behaviour and the environment. Their validity depends on their similarity with the physical environments. This paper aims to validate three environmental-simulation display formats: photographs, 360° panoramas, and virtual reality. To do this we compared the psychological and physiological responses evoked by simulated environments set-ups to those from a physical environment setup; we also assessed the users' sense of presence. Analysis show that 360° panoramas offer the closest to reality results according to the participants' psychological responses, and virtual reality according to the physiological responses. Correlations between the feeling of presence and physiological and other psychological responses were also observed. These results may be of interest to researchers using environmental-simulation technologies currently available in order to replicate the experience of physical environments.
Applied Ergonomics, Volume 65, pp 240-254; https://doi.org/10.1016/j.apergo.2017.05.014
We present an application of engineering and ergonomics principles in the design of a standardised tool, The Dibber, which is a tool with multiple geometric features to fit the diversity of lay-up tasks used in the composites industry. The Dibber is the result of a design process, which consists of a series of observations and prototyping to extract geometric requirements for lay-up tasks. To demonstrate that it is possible to design a standardised tool prototypes of the Dibber were distributed and 91 participants gave feedback. Our results are positive and show consistent patterns of use across industry sectors, as well as between novice and expert laminators.
Applied Ergonomics, Volume 66, pp 9-17; https://doi.org/10.1016/j.apergo.2017.07.016
Upright and slouched sitting are frequently adopted postures associated with increased intradiscal pressure, spinal height loss and intervertebral disc pathology.To examine the effects of two sustained propped slouched sitting (PSS) postures on spinal height after a period of trunk loading.Thirty-four participants without a history of low back pain (LBP) were recruited (age 24.4 ± 1.6 years). Subjects sat in (1) PSS without lumbar support and (2) PSS with lumbar support for 10 min, after a period of trunk loading. Spinal height was measured using a stadiometer.Mean spinal height increase during PSS without lumbar support was 2.94 ± 3.63 mm and with lumbar support 4.74 ± 3.07 mm.Both PSS with and without lumbar support significantly increased spinal height after a period of trunk loading (p < 0.001). Such PSS postures can provide a valuable alternative to upright sitting and may be recommended for recovering spinal height in the working environment following periods of loading.
Applied Ergonomics, Volume 66, pp 1-8; https://doi.org/10.1016/j.apergo.2017.07.013
Low back and neck/shoulder pain are commonly reported among reforestation hand planters. While some studies have documented the intensive cardiovascular demands of hand planting, limited information is available regarding exposures to physical risk factors associated with the development of musculoskeletal disorders (MSDs) among hand planters. This study used surface electromyography (EMG) and inertial measurement units (IMUs) to characterize the muscle activation patterns, upper arm and trunk postures, movement velocities, and physical activity (PA) of fourteen Southeastern reforestation hand planters over one work shift. Results indicated that hand planters are exposed to physical risk factors such as extreme trunk postures (32.5% of time spent in ≥45° trunk flexion) and high effort muscle exertions (e.g., mean root-mean-square right upper trapezius amplitude of 54.1% reference voluntary exertion) that may place them at increased risk for developing MSDs. The findings indicate a need for continued field-based research among hand planters to identify and/or develop maximally effective interventions.
Applied Ergonomics, Volume 65, pp 369-381; https://doi.org/10.1016/j.apergo.2017.07.014
In-car infotainment systems require icons that enable fluent cognitive information processing and safe interaction while driving. An important issue is how to find an optimised set of icons for different functions in terms of semantic distance. In an optimised icon set, every icon needs to be semantically as close as possible to the function it visually represents and semantically as far as possible from the other functions represented concurrently. In three experiments ( N = 21 each), semantic distances of 19 icons to four menu functions were studied with preference rankings, verbal protocols, and the primed product comparisons method. The results show that the primed product comparisons method can be efficiently utilised for finding an optimised set of icons for time-critical applications out of a larger set of icons. The findings indicate the benefits of the novel methodological perspective into the icon design for safety-critical contexts in general.
Applied Ergonomics, Volume 65, pp 362-368; https://doi.org/10.1016/j.apergo.2017.07.008
The rapid increase in the volume of subway passengers in Beijing has necessitated higher requirements for the safety and efficiency of subway corridors. Speed dispersion is an important factor that affects safety and efficiency. This paper aims to analyze the management control methods for reducing pedestrian speed dispersion in subways. The characteristics of the speed dispersion of pedestrian flow were analyzed according to field videos. The control measurements which were conducted by placing traffic signs, yellow marking, and guardrail were proposed to alleviate speed dispersion. The results showed that the methods of placing traffic signs, yellow marking, and a guardrail improved safety and efficiency for all four volumes of pedestrian traffic flow, and the best-performing control measurement was guardrails. Furthermore, guardrails’ optimal position and design measurements were explored. The research findings provide a rationale for subway managers in optimizing pedestrian traffic flow in subway corridors.
Applied Ergonomics, Volume 65, pp 355-361; https://doi.org/10.1016/j.apergo.2017.07.012
Prolonged sitting can cause health problems and musculoskeletal discomfort. There is a need for objective and non-obstructive means of measuring sitting behavior. A ‘smart’ office chair can monitor sitting behavior and provide tactile feedback, aiming to improve sitting behavior. This study aimed to investigate the effect of the feedback signal on sitting behavior and musculoskeletal discomfort. In a 12-week prospective cohort study (ABCB design) among office workers (n = 45) was measured sitting duration and posture, feedback signals and musculoskeletal discomfort. Between the study phases, small changes were observed in mean sitting duration, posture and discomfort. After turning off the feedback signal, a slight increase in sitting duration was observed (10 min, p = 0.04), a slight decrease in optimally supported posture (2.8%, p < 0.01), and musculoskeletal discomfort (0.8, p < 0.01) was observed. We conclude that the ‘smart’ chair is able to monitor the sitting behavior, the feedback signal, however, led to small or insignificant changes.
Applied Ergonomics, Volume 65, pp 335-344; https://doi.org/10.1016/j.apergo.2017.07.002
Brake reaction time is a key component to studying driving performance and evaluating fitness to drive. Although commercial simulators can measure brake reaction time, their cost remains a major barrier to clinical access. Therefore, we developed open-source software written in C-sharp (C#) for measuring driving related reaction times, which includes a subject-controlled vehicle with straight-line dynamics and several testing scenarios. The software measures both simple and cognitive load based reaction times and can use any human interface device compliant steering wheel and pedals. Measures from the software were validated against a commercial simulator and tested for reproducibility. Further, experiments were performed using hand controls in both able-bodied and spinal cord injured patients to determine clinical feasibility for disabled populations. The software demonstrated high validity when measuring brake reaction times, showed excellent test-retest reliability, and was sensitive enough to determine significant brake reaction time differences between able-bodied and spinal cord injured subjects. These results indicate that the proposed simulator is a simple and feasible low-cost solution to perform brake reaction time tests and evaluate fitness to drive.
Applied Ergonomics, Volume 65, pp 326-334; https://doi.org/10.1016/j.apergo.2017.07.011
The perceived hazard and rated importance of standard safety, fluorescent, and neon colors are investigated. Colors are used in warnings to enhance hazard communication. Red has consistently been rated as the highest in perceived hazard. Orange, yellow, and black are the next highest in connoted hazard; however, there is discrepancy in their ordering. Safety standards, such as ANSI Z535.1, also list colors to convey important information, but little research has examined the perceived importance of colors. In addition to standard safety colors, fluorescent colors are more commonly used in warnings. Understanding hazard and importance perceptions of standard safety and fluorescent colors is necessary to create effective warnings. Ninety participants rated and ranked a total of 33 colors on both perceived hazard and perceived importance. Rated highest were the safety red colors from the American National Standard Institute (ANSI), International Organization for Standardization (ISO), and Federal Highway Administration (FHWA) together with three fluorescent colors (orange, yellow, and yellow-green) from 3 M on both dimensions. Rankings were similar to ratings except that fluorescent orange was the highest on perceived hazard, while fluorescent orange and safety red from the ANSI were ranked as the highest in perceived importance. Fluorescent colors convey hazard and importance levels as high as the standard safety red colors. Implications for conveying hazard and importance in warnings through color are discussed.
Applied Ergonomics, Volume 65, pp 345-354; https://doi.org/10.1016/j.apergo.2017.07.005
There is a need for an ecological and complex systems approach for better understanding the development and prevention of running-related injury (RRI). In a previous article, we proposed a prototype model of the Australian recreational distance running system which was based on the Systems Theoretic Accident Mapping and Processes (STAMP) method. That model included the influence of political, organisational, managerial, and sociocultural determinants alongside individual-level factors in relation to RRI development. The purpose of this study was to validate that prototype model by drawing on the expertise of both systems thinking and distance running experts. This study used a modified Delphi technique involving a series of online surveys (December 2016- March 2017). The initial survey was divided into four sections containing a total of seven questions pertaining to different features associated with the prototype model. Consensus in opinion about the validity of the prototype model was reached when the number of experts who agreed or disagreed with survey statement was ≥75% of the total number of respondents. A total of two Delphi rounds was needed to validate the prototype model. Out of a total of 51 experts who were initially contacted, 50.9% (n = 26) completed the first round of the Delphi, and 92.3% (n = 24) of those in the first round participated in the second. Most of the 24 full participants considered themselves to be a running expert (66.7%), and approximately a third indicated their expertise as a systems thinker (33.3%). After the second round, 91.7% of the experts agreed that the prototype model was a valid description of the Australian distance running system. This is the first study to formally examine the development and prevention of RRI from an ecological and complex systems perspective. The validated model of the Australian distance running system facilitates theoretical advancement in terms of identifying practical system-wide opportunities for the implementation of sustainable RRI prevention interventions. This ‘big picture’ perspective represents the first step required when thinking about the range of contributory causal factors that affect other system elements, as well as runners' behaviours in relation to RRI risk.
Applied Ergonomics, Volume 65, pp 316-325; https://doi.org/10.1016/j.apergo.2017.07.009
Applied research on driving and basic vision research have held similar views on central, fovea-based vision as the core of visual perception. In applied work, the concept of the Useful Field, as determined by the Useful Field of View (UFOV) test, divides vision between a “useful” region towards the center of the visual field, and the rest of the visual field. While compelling, this dichotomization is at odds with findings in vision science which demonstrate the capabilities of peripheral vision. In this paper, we examine driving research from this new perspective, and argue for the need for an updated understanding of how drivers acquire information about their operating environment using peripheral vision. The concept of the Useful Field and the UFOV test are not discarded; instead we discuss their strengths, limitations, and future directions. We discuss key findings from vision science on peripheral vision, and a theory that provides insights into its capabilities and limitations. This more complete basic science understanding of peripheral vision informs appropriate use of the UFOV and the Useful Field in driving research going forward.
Applied Ergonomics, Volume 65, pp 309-315; https://doi.org/10.1016/j.apergo.2017.07.010
It is well established that an increase in cognitive task demands is associated with increased pupil diameter. However, the effect of increased motor task demands on pupil diameter is less clear. Previous research indicates that higher motor task complexity increases pupil diameter but suggests that higher motor task precision demands may decrease pupil diameter during task movement. The current study investigated the effect of increased motor task precision on pupil diameter using a Fitts' Law movement task to manipulate motor response precision. Increased precision demands were associated with reduced pupil diameter during the response preparation and response execution phases of the movement trials. This result has implications for the interpretation of pupil diameter as an index of workload during tasks which involve precise motor movements.
Applied Ergonomics, Volume 65, pp 286-308; https://doi.org/10.1016/j.apergo.2017.06.017
Rising energy demands place pressure on domestic energy consumption, but savings can be delivered through home automation and engaging users with their heating and energy behaviours. The aim of this paper is to explore user experiences (UX) of living with an automated heating system regarding experiences of control, understanding of the system, emerging thermal behaviours, and interactions with the system as this area is not sufficiently researched in the existing homes setting through extended deployment. We present a longitudinal deployment of a quasi-autonomous spatiotemporal home heating system in three homes. Users were provided with a smartphone control application linked to a self-learning heating algorithm. Rich qualitative and quantitative data presented here enabled a holistic exploration of UX. The paper's contribution focuses on highlighting key aspects of UX living with an automated heating systems including (i) adoption of the control interface into the social context, (ii) how users' vigilance in maintaining preferred conditions prevailed as a better indicator of system over-ride than gross deviation from thermal comfort, (iii) limited but motivated proactivity in system-initiated communications as best strategy for soliciting user feedback when inference fails, and (iv) two main motivations for interacting with the interface – managing irregularities when absent from the house and maintaining immediate comfort, latter compromising of a checking behaviour that can transit to a system state alteration behaviour depending on mismatches. We conclude by highlighting the complex socio-technical context in which thermal decisions are made in a situated action manner, and by calling for a more holistic, UX-focused approach in the design of automated home systems involving user experiences.
Applied Ergonomics, Volume 65, pp 277-285; https://doi.org/10.1016/j.apergo.2017.06.016
Effective design for presenting severe weather information is important to reduce devastating consequences of severe weather. The Probabilistic Hazard Information (PHI) system for severe weather is being developed by NOAA National Severe Storms Laboratory (NSSL) to communicate probabilistic hazardous weather information. This study investigates the effects of four PHI graphical designs for tornado threat, namely, “four-color”,” red-scale”, “grayscale” and “contour”, on users’ perception, interpretation, and reaction to threat information. PHI is presented on either a map background or a radar background. Analysis showed that the accuracy was significantly higher and response time faster when PHI was displayed on map background as compared to radar background due to better contrast. When displayed on a radar background, “grayscale” design resulted in a higher accuracy of responses. Possibly due to familiarity, participants reported four-color design as their favorite design, which also resulted in the fastest recognition of probability levels on both backgrounds. Our study shows the importance of using intuitive color-coding and sufficient contrast in conveying probabilistic threat information via graphical design. We also found that users follows a rational perceiving-judging-feeling-and acting approach in processing probabilistic hazard information for tornado.
Applied Ergonomics, Volume 64; https://doi.org/10.1016/s0003-6870(17)30136-9
Applied Ergonomics, Volume 65, pp 70-80; https://doi.org/10.1016/j.apergo.2017.06.001
The objective of this research was to quantify the effects of driver age, ramp signage configuration, including number of panels, logo format and sign familiarity, on driver performance and attention allocation when exiting freeways. Sixty drivers participated in a simulator study and analysis of variance models were used to assess response effects of the controlled manipulations. Results revealed elderly drivers to demonstrate worse performance and conservative control strategies as compared to middle-aged and young drivers. Elderly drivers also exhibited lower off-road fixation frequency and shorter off-road glance durations compared to middle-aged and young drivers. In general, drivers adopted a more conservative strategy when exposed to nine-panel signs as compared to six-panel signs and were more accurate in target detection when searching six-panels vs. nine and with familiar vs. unfamiliar logos. These findings provide an applicable guide for agency design of freeway ramp signage accounting for driver demographics.
Applied Ergonomics, Volume 65, pp 61-69; https://doi.org/10.1016/j.apergo.2017.06.002
This laboratory experiment was designed to use fractal dimension as a new method to analyze pupil dilation to evaluate the level of complexity in a multitasking environment. By using the eye-head integrated tracking system, we collected both pupil responses and head positions while participants conducted both process monitoring task and Multi-Attribute Task Battery (MATB-II) tasks. There was a significant effect of scenario complexity on a composite index of multitasking performance (Low Complexity » High Complexity). The fractal dimension of pupil dilation was also significantly influenced by complexity. The results clearly showed that the correlation between pupil dilation and multitasking performance was stronger when the pupil data was analyzed by using the fractal dimension method. The participants showed a higher fractal dimension when they performed a low complexity multitasking scenario. The findings of this research help us to advance our understanding of how to evaluate the complexity level of real-world applications by using pupillary responses.
Applied Ergonomics, Volume 65, pp 51-60; https://doi.org/10.1016/j.apergo.2017.05.012
The rapid growth of attention to visual warnings is a representation of the adaptive behavior of humans. However, the ways warning icons attract attention in the cognition context has yet to be clarified. This research aims to investigate cognitive mechanism of warning icons under various perceptual loads. The results of Experiment A, whose average attentional capture effect of the warning icons (69 ms) was significantly higher than that of the ordinary icons (35 ms), show that compared with ordinary icons, warning icons are prioritized in processing under both high and low perceptual loads. Besides, the attention capturing abilities of non-target warning icons are the same under high and low perceptual loads. To isolate the effects of salient visual features and semantics, warning icons in Experiment B are replaced with transposed icons with saliency but no semantics. The attentional capture effect of warning icons is found to be significantly smaller under high load than under low load, so the effect in Experiment A can be attributed to the semantics of warning icons. In Experiment C the icons of negative and neutral semantics without salient frames are used as interfering stimuli, and the RT to the negative icons (823 ms) was longer than both the RT to the neutral icons (780 ms) and to the no interference icons (743 ms) (P < 0.001), which show that negative icons have stronger attention capturing ability than neutral icons. This research verifies that the semantics of icons is vital, and icons with salient visual features and negative semantics can enhance attentional capture effect.
Applied Ergonomics, Volume 65, pp 81-89; https://doi.org/10.1016/j.apergo.2017.05.008
During long duration journeys, drivers are encouraged to take regular breaks. The benefits of breaks have been documented for safety; breaks may also be beneficial for comfort. The activity undertaken during a break may influence its effectiveness. Volunteers completed 3 journeys on a driving simulator. Each 130 min journey included a 10 min break after the first hour. During the break volunteers either stayed seated, left the simulator and sat in an adjacent room, or took a walk on a treadmill. The results show a reduction in driver discomfort during the break for all 3 conditions, but the effectiveness of the break was dependent on activity undertaken. Remaining seated in the vehicle provided some improvement in comfort, but more was experienced after leaving the simulator and sitting in an adjacent room. The most effective break occurred when the driver walked for 10 min on a treadmill. The benefits from taking a break continued until the end of the study (after a further hour of driving), such that comfort remained the best after taking a walk and worst for those who remained seated. It is concluded that taking a break and taking a walk is an effective method for relieving driving discomfort.
Applied Ergonomics, Volume 64; https://doi.org/10.1016/j.apergo.2017.05.004
Applied Ergonomics, Volume 64, pp 66-74; https://doi.org/10.1016/j.apergo.2017.05.007
In this study, the interaction performances and spatial perceptions in stereoscopic environments were investigated. The experiment compared direct user interactions during pointing at a target, which was continuously visible or presented briefly and disappeared, in both stereoscopic and real environments, at three parallax/depth levels. The position data, collected by a motion system, were used to compute accuracy, signed error, movement time, and throughput. The results showed inaccurate egocentric distance judgment in stereoscopic displays and accurate perceptions in the real world. The overall inaccuracy, which was overestimation of about 10 cm, was relatively better than that achieved in previous studies. The overestimation decreased as the egocentric distance increased. However, providing visual objects did not improve the accuracy. The study concluded that direct pointing could minimize the underestimation problems commonly reported in stereoscopic viewing studies and showed practical significance for developers to focus on incorporating more direct and natural human-virtual reality interactions for improved performance. The findings of this study provide insight towards the development of less expensive displays and their applications. Implications of this work and engineering solutions are also discussed.
Applied Ergonomics, Volume 64, pp 41-46; https://doi.org/10.1016/j.apergo.2017.04.017
Vehicle sounds play an important role concerning customer satisfaction and can show another differentiating factor of brands. With an online survey of 1762 German and American customers, the requirement characteristics of high-quality vehicle sounds were determined. On the basis of these characteristics, a requirement profile was generated for every analyzed sound. These profiles were investigated in a second study with 78 customers using real vehicles. The assessment results of the vehicle sounds can be represented using the dimensions “timbre”, “loudness”, and “roughness/sharpness”. The comparison of the requirement profiles and the assessment results show that the sounds which are perceived as pleasant and high–quality, more often correspond to the requirement profile. High-quality sounds are characterized by the fact that they are rather gentle, soft and reserved, rich, a bit dark and not too rough. For those sounds which are assessed worse by the customers, recommendations for improvements can be derived.
Applied Ergonomics, Volume 65, pp 269-276; https://doi.org/10.1016/j.apergo.2017.07.001
The present study developed a novel touch method for hyperlink selection on smartphones consisting of two sequential finger interactions: press and drag motions. The novel method requires a user to press a target hyperlink, and if a touch error occurs he/she can immediately correct the touch error by dragging the finger without releasing it in the middle. The method was compared with two existing methods in terms of completion time, error rate, and subjective rating. Forty college students participated in the experiments with different hyperlink sizes (4-pt, 6-pt, 8-pt, and 10-pt) on a touch-screen device. When hyperlink size was small (4-pt and 6-pt), the novel method (time: 826 msec; error: 0.6%) demonstrated better completion time and error rate than the current method (time: 1194 msec; error: 22%). In addition, the novel method (1.15, slightly satisfied, in 7-pt bipolar scale) had significantly higher satisfaction scores than the two existing methods (0.06, neutral).