Ergonomics

Studies have revealed that physical and mental demands, psychosocial factors, and individual factors can contribute to the development of WMSDs. Yet, much is still unknown regarding the effects of individual characteristics on WMSDs susceptibility. Previous studies discovered people assumed more awkward body postures to perform an activity when the perception of mental workload is higher. This research study explored if individual characteristics such as age, sex, personality, and anxiety help explain changes or differences in the perception of mental workload and body postures assume when performing activities...

Among a variety of environmental factors, operative temperature, relative humidity and ventilation rate are generally considered to be factors that significantly affect work performance, and the interactions among these three factors were quantitatively studied in this paper. Eighteen participants were recruited to complete the neurobehavioral ability tests in different environments by central composite design, and their performance was analysed by regression fitting and multi-factor coupling analysis. By defining the interval coefficient β, the interaction effects between the factors were calculated quantitatively...

Bainbridge's Ironies of Automation was a prescient description of automation related challenges for human performance that have characterised much of the 40 years since its publication. Today a new wave of automation based on artificial intelligence (AI) is being introduced across a wide variety of domains and applications. Not only are Bainbridge's original warnings still pertinent for AI, but AI's very nature and focus on cognitive tasks has introduced many new challenges for people who interact with it...

Our long accepted and historically-persistent human narrative almost exclusively places us at the motivational centre of events. The wellspring of this anthropocentric fable arises from the unitary and bounded nature of personal consciousness. Such immediate conscious experience frames the heroic vision we have told to, and subsequently sold to ourselves. But need this centrality necessarily be a given? The following work challenges this, oft unquestioned, foundational assumption, especially in light of developments in automated, autonomous, and artificially-intelligent systems...

Accident analysis methods are used to model the multifactorial cause of adverse incidents. Methods such as AcciMap, STAMP-CAST and recently AcciNet, are systemic approaches that support the identification of safety interventions across sociotechnical system levels. Despite their growing popularity, little is known about how reliable systems-based methods are when used to describe, model and classify contributory factors and relationships. Here, we conducted an intra-rater and inter-rater reliability assessment of AcciMap, STAMP-CAST and AcciNet using the Signal Detection Theory (SDT) paradigm...

Environmental institutions are realising that the human-nature relationship is a tangible target for a sustainable future. Societal change of that relationship is a challenge involving modifications to both systems and human behaviours. We argue that as Human Factors and Ergonomics (HFE) focusses on relationships, interfaces and systems it is well placed to contribute. After introducing the state of HFE and nature connectedness science an analysis of areas of HFE and human-nature connectedness themes is used to consider current work and future opportunities...

Surgical team members in perioperative environments experience high physical demands. Interventions such as exoskeletons, external wearable devices that support users, have the potential to reduce these work-related physical demands. However, barriers such as workplace environment and task compatibility may limit exoskeleton implementation. This study gathered the perspectives of 33 surgical team members: 12 surgeons, four surgical residents, seven operating room (OR) nurses, seven surgical technicians (STs), two central processing technicians (CPTs), and one infection control nurse to understand their workplace compatibility...

Firefighters often experience low back pain (LBP), but their back muscle characteristics are not well studied. This study aimed to 1) compare the biomechanical characteristics of back muscles and self-reported back disabilities in frontline firefighters with and without LBP history, and 2) examine the relationships between back disability and biomechanical measurements. We recruited 42 male firefighters and assessed their perceived pain and disabilities, maximum isometric back extension strength, passive stiffness, and fatigability of the longissimus...

Anthropometry is vital to provide design references when seeking proper product fit. Nowadays, 3D anthropometry is widely used to provide more size and shape details for improving product designs. However, 3D ear anthropometry is still at an explorative stage, considering the complex ear morphology and other technical obstacles. The proposed research method in this study is applicable to analyze the 3D point cloud of the entire external ear. With the cross-parameterization technique, the dataset was used to explore the morphological characteristics of the ear...

Back exosuits deliver mechanical assistance to reduce the risk of back injury, however, minimising restriction is critical for adoption. We developed the adaptive impedance controller to minimise restriction while maintaining assistance by modulating impedance based on the user's movement direction and nonlinear sine curves. The objective of this study was to compare active assistance, delivered by a back exosuit via our adaptive impedance controller, to three levels of assistance from passive elastics. Fifteen participants completed five experimental blocks (4 exosuits and 1 no-suit) consisting of a maximum flexion and a constrained lifting task...

Due to differences in actuation and design, active and passive industrial back exoskeletons could influence functional performance, i.e., work performance, perceived task difficulty, and discomfort, differently. Therefore, this study investigated and compared the impact of the active CrayX (7 kg) and passive Paexo Back (4.5 kg) on functional performance. Eighteen participants performed twelve work-related tasks with both types of exoskeletons and without (NoExo). The CrayX hindered work performance up to 22% in multiple tasks, compared to the Paexo Back and NoExo, while work performance between NoExo and the Paexo Back condition was more comparable, except for stair climbing (13% hindrance)...

Recent studies on occupants' safety in reclined positions suggest that a more inclined seat pan could be needed to reduce the occurrence of submarining. This study aimed to investigate whether a more inclined seat pan would also be comfortable for occupants. Eighteen volunteers participated in the experiment. They were asked to self-select seat pan inclination for seat back angles from 20 to 60 degrees using a reconfigurable experimental seat from two initial seat pan angles (10 and 40 degrees from the horizontal)...

The After-Action Review (AAR) in Virtual Reality (VR) training for police provides new opportunities to enhance learning. We investigated whether perspectives (bird's eye & police officer, bird's eye & suspect, bird's eye) and line of fire displayed in the AAR impacted the officers' learning efficacy. A 3 x 2 ANOVA revealed a significant main effect of AAR perspectives. Post hoc pairwise comparisons showed that using a bird's eye view in combination with the suspect perspective elicits significantly greater learning efficacy compared to using a bird's eye view alone...

Several methods have been put forward to quantify cumulative loads; however, limited evidence exists as to the subsequent damages and the role of muscular fatigue. The present study assessed whether muscular fatigue could affect cumulative damage imposed on the L5-S1 joint. Trunk muscle electromyographic (EMG) activities and kinematics/kinetics of 18 healthy male individuals were evaluated during a simulated repetitive lifting task. A traditional EMG-assisted model of the lumbar spine was modified to account for the effect of erector spinae fatigue...

Indoor temperature has a critical impact on the performance of office workers. This study aimed to evaluate the effect of indoor temperature on work performance through subjective assessments, neurobehavioral tests, and physiological measurements. The experiment was conducted in a controlled office environment. Under each temperature condition, participants voted on their perception of thermal sensation, thermal satisfaction, and sick building syndrome (SBS) symptoms. Participants were given neurobehavioral tests based on a ten-item task, and their body temperature, blood pressure, heart rate, and blood oxygen saturation were measured before and after the tests...

Knowledge gaps exist on association between law enforcement officer (LEO) anthropometric characteristics and perceived body armor fit, armor discomfort, and armor-caused pain. This study assessed the correlation and identified influential torso dimensions for armor sizing and design applications. Nine-hundreds and seventy-four LEOs across the U.S. participated in a national study on LEO armor use and body dimensions. Perceived ratings of armor fit, armor discomfort, and body pain were found moderately correlated with each other...

Road transport is experiencing disruptive change from new first-of-a-kind technologies. While such technologies offer safety and operational benefits, they also pose new risks. It is critical to proactively identify risks during the design, development and testing of new technologies. The Systems Theoretical Accident Model and Processes (STAMP) method analyses the dynamic structure in place to manage safety risks. This study applied STAMP to develop a control structure model for emerging technologies in the Australian road transport system and identified control gaps...

Visual design form is an important factor affecting users' cognition of icons, which plays an important role in visual search and the perception of the status shown by icons. In the graphical user interface, the icon color is regularly used to indicate the running state of a function. The aim of this study was to investigate the effects of icon color features on user perception and visual search performance under different background colors. There were three independent variables in the study, including background color (white and black), icon polarity (positive and negative) and icon saturation (60%、80% and 100%)...

To investigate whether high cognitive task load (CTL) for aircraft pilots can be identified by analyzing heart-rate variability, electrocardiograms were recorded while cadet pilots (n = 68) performed the plane tracking, anti-gravity pedaling, and reaction tasks during simulated flight missions. Data for standard electrocardiogram parameters were extracted from the R-R-interval series. In the research phase, low frequency power (LF), high frequency power (HF), normalized HF, and LF/HF differed significantly between high and low CTL conditions ( P <...

Recent research indicates that installing shoulders on rural roads for safety purposes causes drivers to steer further inside on right bends and thus exceed lane boundaries. The present simulator study examined whether continuous rather than broken edge-line delineation would help drivers to keep their vehicles within the lane. The results indicated that continuous delineation significantly impacts the drivers' gaze and steering trajectories. Drivers looked more towards the lane centre and shifted their steering trajectories accordingly...