Applied Ergonomics

Safety is a constant priority for the railway industry and there are numerous hazards in and around the rail system which may result in damage to train and environment, human injury and fatalities. Low levels of human and organisational performance have been shown to be a prime cause of railway accidents and a number of accident models and methods have been developed in order to probe deeper into the role played by organisational factors in accident causation. The Systems-Theoretical Accident Modelling and Processes (STAMP) method for example, represents a promising systematic and systemic way of examining sociotechnical systems such as the railway...

Biomechanical overload in the wrist flexor and extensor muscles, together with awkward hand positions during work activities, can result in occupational wrist and hand disorders. Dairy workers, specifically those that work in the milking parlor, are exposed to highly repetitive and forceful exertions of the upper limb throughout their work shift. There are very few studies that have investigated the determinants that contribute to the risk of distal upper limb musculoskeletal disorders among dairy workers. The purpose of the present study was to identify the variables affecting the biomechanical overload of the distal upper limb among milking parlor workers, define risk profiles, and propose possible interventions to reduce the high physical loads to the distal upper limb during milking activities...

Healthcare-associated infections are a serious worldwide health concern. Although contaminated medical devices are an avenue for infection, little research has evaluated the techniques used to open sterile packages. The goal of this study was to develop a method to quantify aspects of the package opening process in accordance with opening guidelines and then to demonstrate this methodology through a small sample of clinicians opening two sizes of pouch-style packages. Using motion capture techniques, a method was designed to quantify 11 parameters associated with the opening process...

The aim of this study was to assess postures and movements of the trunk and upper arm during paper mill work, and to determine the extent to which they differ depending on method of assessment. For each of 28 paper mill workers, postures and movements were assessed during three full shifts using inclinometer registration and observation from video. Summary metrics for each shift, e.g., 10th , 50th , and 90th posture percentile, were averaged across shifts and across workers. In addition, the standard deviation between workers, and the standard deviation between shifts within worker were computed...

The aim of this study was to compare the feasibility and impact of sit-stand workstations plus advice, with or without exercise, on back pain and sitting time in office workers at risk of low back pain (LBP). Eligible participants (n = 29/169; 17% overall) were randomized to receive a sit-stand workstation and advice with (n = 16) or without (n = 13) progressive resistance exercise training for 4-weeks. Feasibility (recruitment, acceptability, adherence) and impact (LBP severity during a standardized standing task, workplace-sitting time) were assessed...

With a scarcity of research on multiple working arrangements, the aim of the paper is to contribute empirical data from a Norwegian engineering, procurement, and construction enterprise that shed light on the challenges and benefits of a 14-21 working arrangement in itself and in relation to other working arrangements. We combine a sociotechnical system perspective with systematic content analysis using QSR NVivo, which reveals organizational complexity comprised of indirect, direct, positive, negative, and mutual interplays between various aspects of the enterprise, including processes and outcomes...

Assistive devices (ADs) are products designed to overcome the grip strength and mobility difficulties produced by ageing and different pathologies. Nevertheless, little is known about the postural effect of such devices. This work aims to quantify this effect on the entire upper limb. Ten healthy right-handed subjects performed 13 activities of daily living (ADL) with normal products and 22 ADs and both arm (shoulder, elbow and wrist) and hand (grasp types and contacts) postures were analysed. ADs were found to affect upper limb postures in ADL, reducing the use of precision grasps in the right hand by 31...

The purpose of this study is to examine the differences in pressure sensitivity for areas of the foot in a toe-off position and with the feet on the ground. This data could provide a base for adapting the softness of different areas while designing footwear. 21 healthy subjects are asked to participate in a test where a researcher applies pressure with an advanced force gauge in 20 locations on the foot until the subject starts experiencing discomfort. Rigid shells of three sizes have been designed and 3D printed based on 3D foot scans...

Night vision goggles (NVGs) enable aircrew to complete missions in the cover of night, but dramatically increase and alter the distribution of mass borne by the head. Our novel approach to visual target acquisition, based on Fitts' Law, was used to assess differences across three different performance metrics between low (L) and high (H) head supported mass (HSM) conditions. Fifteen healthy male participants completed time-optimal and reciprocal visual target acquisitions between target pairs arranged in four different movement trajectories...

A novel anatomically shaped ("anatomical") woodworking chisel handle was developed for wood scraping operation. 18 students participated in an evaluation study to compare the new handle against seven readymade handles of ¾-inch bench chisels in the context of a standard wood scraping task. A comfort questionnaire for hand tools (CQH) and a hand-based pain map were used for evaluating and comparing the handles. 'Functionality' and 'sweating' were found to be the most and least important comfort concerns, respectively...

The development of musculoskeletal disorders has been linked to various risk factors in the work environment including lifting heavy loads, machine and materials handling, work postures, repetitive work, work with handheld vibrating tools, and work stress. The Quick Exposure Check (QEC) was designed to assess exposure to work-related musculoskeletal risk factors affecting the back, shoulder/arm, wrist/hand, and neck. We investigated the inter-rater reliability of the summary scores and individual items of the QEC by comparing two simultaneous assessments of 51 work tasks, performed by 14 different workers...

Well-designed handrails significantly enhance balance recovery, by allowing users to apply high forces to the rail and stabilize their center of mass. However, data on user-applied handrail forces during balance recovery are limited. We characterized the peak forces that 50 young adults applied to a handrail during forward and backward falling motions; quantified effects of handrail height (34, 38, 42 inches) and position prior to balance loss (standing beside the rail with or without hand contact, or facing the handrail with two-handed contact); and examined the relationship between handrail forces and individual mass...

This paper focuses on the comparative assessment of comfort and discomfort (hereafter, (dis-)comfort) for aircraft seating. Subjective and objective data of seating (dis-)comfort were collected during an experiment involving 20 volunteers who tested 3 aircraft double-seats in upright and reclined position. In order to minimize experimental uncertainty due to well-known noise factors (i.e. patterns of discomfort during the work week and during the work day, order of evaluation, inter-individual differences), experimental trials were performed according to a crossover design...

Inattention can be considered a primary cause of vehicular accidents or crashes, and in-car warning signals are applied to alert the driver to take action even in automated vehicles. Because of age related decline of the older driver's abilities, in-car warning signals may need adjustment to the older driver. We therefore investigated the effects of uni-, bi- and trimodal directional warnings (i.e., light, sound, vibration) on young and older drivers' responses in a driving simulator. A young group of 15 drivers (20-25 years of age) and an older group of 16 drivers (65-79 years of age) participated...

Despite the long history of automotive head-up displays (HUDs), what information they should display in different situations to best serve the driver remains unanswered. The lack of understanding hinders designing useful automotive HUD systems. In an effort to address this, the current study investigated the developer, researcher and user perspectives on the functional requirements of automotive HUDs through literature review. The review results indicated that: 1) the existing commercial HUDs perform largely the same functions as the conventional in-vehicle displays, 2) past research studies proposed various HUD functions for improving driver situation awareness and driving safety, 3) autonomous driving and other new technologies are giving rise to new HUD information, and 4) little research is currently available on HUD users' perceived information needs...

Manual materials handling is often performed in hazardous environments where protective footwear must be worn; however, workers can wear different types of footwear depending on the hazards present. Therefore, the goal of this study was to investigate how three-dimensional lifting mechanics and trunk local dynamic stability are affected by different types of protective footwear (i.e. steel-toed shoes (unlaced boot), steel-toed boots (work boot), and steel-toed boots with a metatarsal guard (MET)). Twelve males and twelve females performed a repetitive lifting task at 10% of their maximum lifting effort, under three randomized footwear conditions...

This study was conducted to examine the effect of a posture correction-based intervention (with a biofeedback device) on the occurrence of musculoskeletal symptoms (MSS) and fatigue among control room operators in a petrochemical plant in Iran. A total of 188 office workers (91 in the case group and 97 in the control group) participated at baseline as well as at 6- and 12-month follow-up. A questionnaire survey (including the Nordic Musculoskeletal Questionnaire and Multidimensional Fatigue Inventory) and direct observations of working postures by using the Rapid Upper Limb Assessment (RULA) method were used...

Several innovative measures in traffic control applied in Europe have successfully improved the comfort and safety of cycling, among which is the green waves for cyclists. Consecutive traffic lights are synchronised to create a green wave, increasing comfort and decreasing waiting times and related deliberate red-light running. This study focused on exploring the user acceptance of green wave systems and the user evaluation of six distinct interface designs (i.e. numeric-based countdown, dot-based vertical countdown, dot-based clockwise countdown, LED line, LED road surface, on-bike speed indicator)...

Increasing concerns about musculoskeletal disorders in the upper back arising from excessive daily use of the smartwatch have been widely validated by the rising prevalence of discomfort. This study explored the smartwatch as a potential ergonomic intervention over the smartphone. Fourteen healthy participants completed five tasks (application setting, calling, message typing, message checking and vocal message entry) with smartphone and smartwatch in both sitting and standing postures. The neck-shoulder kinematics and muscle activation levels were monitored to assess the effects of the tasks, devices, and postures...

Load carriage induces systematic alterations in gait patterns and pelvic-thoracic coordination. Leveraging this information, the objective of this study was to develop and assess a statistical prediction algorithm that uses body-worn inertial sensor data for classifying load carrying modes and load levels. Nine men participated in an experiment carrying a hand load in four modes: one-handed right and left carry, and two-handed side and anterior carry, each at 50% and 75% of the participant's maximum acceptable weight of carry, and a no-load reference condition...