Ergonomics最新文献

Time spend using smartphones is constantly increasing. Portability leads to postures that expose them to musculoskeletal disorders (MSDs). The aim was to study the effect of time of day (morning, afternoon, evening and night) on university students' postures when using their smartphones over the weekend and their link with MSD risk. A cross-sectional survey was conducted among 277 university students (25.3% female, 74.7% male, 17-24 years). SmarTaxo with 41 postures (sitting, standing, lying, walking) and their relative RULA (Rapid Upper Limb Assessment) scores were considered. The overall distribution of postures was: 36.22% sitting, 17.53% standing, 37.67% lying down and 8.57% walking. Six lying and one standing posture observed in the evening and at night are at high MSD risk (RULA score = 6, 23% of total time). The survey highlighted that university students are exposed to MSDs during the weekend day due to awkward postures, especially when lying down at night.

An ergonomic assessment was conducted to quantify the activities and physical demands during the British Army's 8-week Platoon Sergeant and Section Commander Battle Courses (PSBC, SCBC). Twenty PSBC and 18 SCBC male infantry soldiers volunteered. Body Mass (BM) was measured pre- and post-course, with course physical activity levels (PAL), energy expenditure (EE) and sleep profiles quantified using tri-axial accelerometery. The courses were predominately field-based, involving slow and rapid load carriage tasks, digging and moving casualties. Average daily EE (SCBC = 4020 ± 599 vs. PSBC = 3876 ± 525 kcal.day^-1; p>0.05) and BM decreases were similar (SCBC = -3.9 ± 2.9 vs. PSBC = -2.0 ± 2.7 kg; p>0.05). Daily PAL was higher for SCBC than PSBC (2.1 ± 0.3 vs. 2.0 ± 0.3, p=0.041), likely due to greater moderate-vigorous activity levels (p=0.003). Daily sleep durations were variable, but similar across courses (≈5.1 hr.day^-1; p>0.05). These data confirm these courses are arduous and can be used to inform course-specific physical screening tests and training to increase course success.

We compared shoot/don't shoot task (SDST) performance in law enforcement officers (LEOs) and non-officers under normal cognitive load, and under higher load induced by processing a complex dispatch message. We also examined the effects of participants' behavioural activation (BAS) and inhibition (BIS) systems, impulsivity, and working memory on SDST performance. Stimuli were videos of shoot and don't shoot variations performed by three actors. Dependent measures were shoot errors, fail-to-shoot errors, response time, and shooting accuracy. Compared to non-officers, LEOs were more accurate and adapted to make fewer fail-to-shoot errors. They were not faster, and did not make fewer shoot errors. Compared to normal cognitive load, under higher load, participants were quicker and more accurate, but made more shoot errors. The higher cognitive load condition revealed effects that were not present under normal load. Participants making more shoot errors had higher BAS, and BIS than those making fewer or no errors.

This study investigated whether bidirectional transparency, compared to agent-to-human transparency, improved human-agent collaboration. Additionally, we examined the optimal transparency levels for both humans and agents. We assessed the impact of transparency direction and level on various metrics of a human-agent team, including performance, trust, satisfaction, perceived agent's teaming skills, and mental workload. A total of 30 participants engaged in a human-agent collaborative game in a within-subject experiment with five conditions: a 2 (transparency directions: agent-to-human transparency vs. bidirectional transparency) × 2 (transparency levels: reasoning transparency vs. reasoning + projection transparency) factorial design, plus an additional action transparency condition as a control condition. The findings indicated that bidirectional transparency improved task performance without increasing the mental workload. This study recommends a bidirectional transparency mechanism, in which the agent provides transparency to humans regarding its reasoning and predictions, whereas humans offer transparency to the agent regarding their reasoning. Practitioner Summary: This study highlights the importance of bidirectional transparency in human-agent collaboration, demonstrating its effectiveness in enhancing task performance without increasing mental workload. It recommends implementing a mechanism where both humans and agents share transparency information, optimising collaboration outcomes.

3D scanning capture complex ear morphology, but most research focuses on dimensions defined by product design or ergonomic guidelines, often missing crucial 3D details, especially those of ear canal for in-ear product design. This study conducted a statistical shape analysis on the 3D geometry of the cavum concha and the external auditory meatus (EAM) using 1195 scans of Chinese ears. A surface registration method was adopted to standardise and align ear models for shape analysis. Principal component analysis (PCA) generated statistical models of ear shapes, with the most significant variation reflecting the overall width of the cavum concha, explaining 29.63% of the variation. The k-means++ algorithm was employed to classify ear shapes using the first 15 principal component scores, identifying four shape categorisations. Significant variations and shape modes of ear shape were identified, and the derived statistical shape models provide essential 3D references for the ergonomic design of ear-related products.

This research aims to enhance the comprehension of 3D human modelling methodologies pertinent to the garment ergonomics field. Through a search and analysis of 442 literatures, this study found that, despite the utilisation of high-resolution scanning and sophisticated 3D software, generating the vast diversity of human physiques in models remains a formidable challenge, attributed to issues such as data discrepancies and loss of detail from self-occlusion. Furthermore, through an exhaustive literature survey, this research formulates a framework for juxtaposing various modelling methodologies, analysing their technical tenets, benefits, and limitations from a synergetic and iterative standpoint. Finally, the article underscores future research trajectories, emphasising the critical need to ameliorate model precision and operational efficiency, alongside the integration of garment ergonomics knowledge into 3D human modelling. This research furnishes valuable insights and directions for forthcoming studies, aiming to drive the progression of garment ergonomics towards a more genuine and efficient.

The concept of touchscreen primary control device is a novel approach of touchcreen implentation. The objective of this study is to investigate differences in flight performance and attention allocation between a touchscreen inceptor and a traditional sidestick. Twenty-one participants flew four simulated instrument landing system (ILS) approaches - with the touchscreen inceptor or traditional sidestick - during flight scenarios where an aircraft attitude disturbance was either present or absent. Results demonstrated that participant performance scores were worse with the touchscreen inceptor compared to the sidestick during attitude disturbance scenarios. Interestingly, participants exhibited reduced attention to external visual cues with the touchscreen inceptor compared to the sidestick. In addition, use of the touchscreen inceptor resulted in lower performance and lower self-reported situation awareness. Overall, the touchscreen inceptor demonstrated poorer performance compared to the traditional sidestick, highlighting limitations in its current design that warrant cautious consideration and further investigation.

Workers in manufacturing settings experience highly variable musculoskeletal loading, which current risk assessment methods often fail to fully capture. This study evaluated a Fatigue Failure-Based framework for estimating continuous lumbar loading from variable occupational loads. Worker movements and postures were recorded using Inertial Motion Capture technologies, and L5/S1 joint loading history was estimated through inverse dynamics. Stress cycles were analysed using Rainflow analysis, adjusted with Goodman's method, and summed using Palmgren-Miner rule to estimate cumulative damage. The framework was tested in live industrial settings with eight automotive workers across 108 trials. Logistic regression models demonstrated significant correlations between cumulative damage estimates and self-reported low-back pain (OR = 2.16, 95% CI: 1.30, 3.57). This framework provides a novel method for analysing highly variable loading to estimate cumulative exposure in ergonomics, offering a starting point for future research and potential applications in assessing low back injury risks in similar occupational settings.

Police officers wear personal protective equipment (PPE) to reduce their risk of injury while on duty. Despite the unique policing activity of riding a horse, little is known about the PPE used by mounted officers. The aim of this research was to assess the use, comfort, and functionality of mounted police PPE. Twenty officers from three UK Mounted Sections were recruited. Semi-structured interviews and range of movement assessments were conducted. Interview data was analysed using reflexive thematic analysis. Three main themes were generated: Functional requirements, Issues, and Areas for improvement. Much of the PPE worn by mounted officers is not designed for the risks associated with horse riding. There was a sense that officers 'make do' with their current PPE provision, but increased protection from falls and mounted specific public order protection were identified as particular areas for improvement.

A safe, healthy and competent workforce in the wind power industry is essential for meeting climate goals and energy needs. Wind technicians conduct critical tasks on wind turbines often in remote, hazardous environments in onshore and offshore locations. However, industry incident data indicate safety concerns in relation to operations and maintenance work. Despite behavioural issues significantly contributing to these wind incidents, the limited human factors research in the wind sector typically focuses on design and physiology. A scoping review was carried out to examine the psychological and organisational factors that impact on wind technician safety, health, and performance. In total, 13 research articles examining human factors in wind were identified, as well as 8 items from the grey literature. A preliminary framework was developed encompassing individual, crew/team, organisational factors, and task and environmental factors. This framework can be used to direct future research and assist practitioners to design effective interventions.