International Journal of Human Factors and Ergonomics (10 papers in press)
Boredom makes me nervous: Fidgeting as a strategy for contrasting the lack of variety
by Orlando Ricciardi, Piero Maggi, Francesco Di Nocera
Abstract: Many studies on human performance in sustained attention tasks has been conducted since the first half of the last century. Despite results describe boredom as the leading cause in depleting attentional resources, the understanding of its relationship with human performance has been limited by the unavailability of observational measures. This study attempts to overcome this limitation by focusing on fidgeting (brief, repetitive and involuntary body movements) as a behavioural outcome of boredom. An experimental study was devised, and the performance of individuals involved in a meaningless and a meaningful version of the same task was compared. A custom system based on Arduino technology was used for detecting movements. Results showed that individuals made more aimless movements in the meaningless condition, therefore confirming that increase fidgeting may be used to introduce variability where it lacks. Fidgeting seems a promising candidate measure for the operator functional state that could be used in many operational settings.
Keywords: boredom; mental workload; fidgeting; human performance; auto-feedback.
Human Factors issues in aircraft maintenance
by Phillip Tretten, Jörgen Normark
Abstract: Highly specialised personnel are dependent upon others and diverse systems to perform error free aircraft maintenance actions. Research has shown that the maintenance process can be improved to reduce errors and improve usability. Using a mobile tool to aid the maintenance work seem to have great benefits. The goal of this project was to practice user-centred design to explore what human factors issues for maintenance personnel can be addressed by a mobile tool in order to make the most out of maintenance planning, execution, and follow-up. Interviews and observations of military aircraft maintenance personnel were conducted at an air force unit. Six areas that can be improved by the use of a mobile tool were identified; several information sources must constantly be consulted, information is constantly transferred between different locations and between media types, technical documentation can be inconsistent and hard to access, there are strict hierarchies and certifications of personnel, the means of recording and transferring communicative information are insufficient, and there can be a long lag time for updates, error reporting and feedback of actions. These areas point towards a need for an improved tool that could contain all the information sources and record relevant maintenance information.
Keywords: Aircraft maintenancernHuman FactorsrnHuman errorrnMaintenance; User interface.
Exploring the concept of passenger well-being in the context of automated driving
by Vanessa Sauer, Alexander Mertens, Jens Heitland, Verena Nitsch
Abstract: Motorized mobility is evolving with the introduction of driving automation. The transition from driver to passenger requires a renewed focus on passengers and their needs while travelling, making passenger well-being a highly interesting concept to investigate. However, as of yet, it is also unclear how passenger well-being may be operationalized and which factors may contribute to passenger well-being in this domain. An exploratory study (n = 40) indicated that passenger well-being can be understood as current subjective well-being and that it can be measured reliably using self-reported measures. Further, multiple regression analyses showed that depending on how well the individual preferences are met by the vehicle interior, passenger well-being is either predicted by perceived safety, aesthetics and symbolism (preferences met) or by physical well-being and distrust (preferences not met).
Keywords: subjective well-being; SWB; passenger well-being; affect; automated driving; autonomous driving; transportation; vehicle interior; conceptualization; measure evaluation; self-reported measure; user study; user preferences.
Behavior-Based Safety Approach to Improving Workplace Safety in Heavy Equipment Manufacturing Industry
by Dinagaran D, Balasubramanian K.R., Sivapirakasam S.P., Kuruva Gopanna
Abstract: The Behavior-Based Safety (BBS) approach is the "use of science for changing the behavior of an individual. BBS focuses on employees actions in terms of day-to-day safety behavior and their improvement. Implementation of BBS in an industry can significantly impact the entire organization by reducing accidents, improving employee retention rates, improving health, welfare, and job satisfaction. This research work on the BBS approach is carried out at the work center of a boiler waterwall panel fabrication area which falls into the category of heavy equipment manufacturing industry for improving workplace safety. The heavy equipment manufacturing industry produces high-pressure boiler components, valves, and accessories. Seven Steps are used to develop and implement the BBS approach. The waterwall panel fabrication work center consists of 80 employees. Among those, 76 permanent workers like fitters, welders and crane operators are employed to carry out skilled work, and four contract laborers are employed to do unskilled work. The results of this research work show that an effective measure of safety behavior with appreciative or constructive feedback is important for positive behavioral changes among the workers to improve the safety performance in the workplace. The safety performance at the waterwall panel fabrication area had improved from the baseline of 57.35% to 77.94 % with the intervention of the BBS approach by the end of the 4th week. The results also revealed that implementation of the BBS approach is a system with the potential to achieve meaningful safety improvements in manufacturing industries.
Keywords: Behavior-Based Safety; Appreciative Feedback; Constructive Feedback; Heavy Equipment Manufacturing Industry; Safe Behavior.
A Participatory Ergonomics Approach to Prevention of Musculoskeletal Disorders in Portuguese Small and Medium Enterprises: Ergo@Office
by Tania Lima, Denis Coelho.
Abstract: A participatory ergonomics programme enables a company to engage employees in its preventive strategy. Ergo@Office is an integrated methodology for continuously implementing preventive measures while monitoring their effectiveness over time in a participatory manner. It is a simple and economic tool useful for the identification of the need for implementation of interventions for strategic musculoskeletal disorders prevention. Ergo@Office is directed towards computerized workplaces and aims to identify and assess ergonomic risks, psychosocial factors related to the work context, musculoskeletal complaints and symptoms of disorders and individual characteristics and habits. This is followed by the design and implementation of an action plan for ergonomic intervention. In the first phase, occupational safety and health services (OSHS) apply the Ergo@Office risk factor identification methodology. The main objective of the training that ensues is to provide workers with skills that enable proposing an intervention plan for their work station and adopting an attitude of prevention and continuous improvement. The second phase of the methodology is the responsibility of the occupational health and safety services. Its results are compared with the proposal presented by the employee. To this follows application of suitable risk assessment methods to situations where ergonomic mismatches were detected when observing the work stations in the workplace, with guidance provided by completing a checklist. In the final phase, OSHS will recommend and prioritize preventive and corrective measures to be implemented in each job, devising an individualized ergonomic intervention plan for each employee. As a practitioner tool, Ergo@Office deploys a participatory approach to ergonomics in both the analysis and intervention phases. The implementation of the measures envisaged in this plan result from teamwork between the OSHS and the worker whose work is being focused. The implemented measures should be monitored, which will enable assessing the effectiveness of the recommended measures and their adjustment to the labour scenario in an up-to-date way.
Keywords: Musculoskeletal Disorders (MSD); Psychosocial Factors; Individual Characteristics; Computerized Work; Occupational Safety and Health.
VEHand: an in-vehicle information system to improve driving performance in an unfamiliar traffic regulation
by Hasan Alyamani, Manolya Kavakli, Stephen Smith
Abstract: Driving under unfamiliar traffic regulations (UFTR) is associated with an increased number of traffic accidents. In order to drive safely in such conditions, drivers need to adapt their prior knowledge to a new driving situation. This ability is referred to as cognitive flexibility (CF). Previous studies have found that CF is influenced by the degree of handedness of the performer. That is, left- and mixed-handed people show superior CF compared to strong right-handed people in tasks that require adaptation in performance. The goal of this research was to develop a driving-assistance system that adapts the information it provides based on the handedness degree of drivers under UFTR. In this paper, UFTR refers to driving under a keep-left traffic regulation for those who are only familiar with driving under a keep-right regulation. Two empirical studies were conducted in a driving simulator. The first study explored the relationship between degree of handedness and driving performance among participants driving in an UFTR, particularly at roundabouts and intersections. Left/mixed-handed drivers made significantly fewer errors that could be attributed to CF impairment than did strong right-handed drivers. Based on the results from the first study, we developed the implementation of the VEHand prototype. VEHand is a driving-assistance system specifically designed for driving under UFTR that provides drivers with useful visual feedback based on their handedness degree. The second study evaluated the effectiveness of VEHand in improving driving performance using a cross-over study design. The results indicated that VEHand significantly assisted strong-right handed drivers to correctly enter upcoming roundabouts and intersections.
Keywords: Cognitive flexibility; driving performance; in-vehicle information system; degree of handedness; driving simulator; unfamiliar traffic regulation; roundabout; intersections.
Exploratory Study on Adequacy of Upper Extremity Position during Smartphone Usage
by Hanyeong Yun, Taelim Yoon
Abstract: This study compared the effects of the prone, side-lying, and sitting positions during smartphone use. Positions can cause discomfort in the upper extremity musculoskeletal system. Thirty healthy young adults were recruited and instructed to type on a smartphone for 5 minutes in each position and 5 minutes rest between each position. Electromyography data acquired from the upper extremity muscles were analysed using the Amplitude Probability Distribution Function (APDF) method. Wrist and elbow joint angles were assessed using the motion analysis system (Myomotion). In 50% of APDFs, the flexor carpi ulnaris muscle displayed higher muscle activity in the side-lying position, whereas the abductor pollicis brevis (APB) and extensor carpi ulnaris (ECU) muscles showed higher muscle activity in the sitting position. In 90% of APDF, the upper trapezius, ECU, and APB muscles showed higher muscle activity in the sitting position. Additionally, the side-lying position showed a neutral wrist extension angle of 0
Keywords: Smartphone; Typing; Positions; Sitting; Prone; Side-lying; Surface Electromyography; Myomotion; APDF.
Special Issue on: CNB2019 Biomechanics for Performance and Well-being
Increased Bone Conducted Vibration reduces motion sickness in Automated Vehicles
by Spencer Salter, Stratis Kanarachos, Cyriel Diels, Paul Herriots, Didier Depireux, Doug Thake
Abstract: Motion sickness is common within many forms of transport, it affects most of the population who experience some symptoms at some time. Automated Vehicles (AV) offer productivity benefits but also increased incidence of motion sickness. There are mitigation methods with varying degrees of effectiveness to combating motion sickness. Bone Conductive Vibration (BCV) has been proven to be better than control for motion sickness mitigation. It is not known if the level of vibration is important. Twenty-nine participants were subjected to normal urban driving whilst undertaking a gaze down Non-Driving Related Task (NDRT) within an AV cabin. High and low device settings were randomly chosen as were the seating positions. Twenty-five participants successfully completed the experiment. It was found that the device significantly increased the time to nausea up to a factor of 1.6 when set to high over low settings. BCV did not improve task performance.
Keywords: Automated Vehicles; Bone Conducted Vibration; Motion Sickness; Mitigation; tinnitus.
Biomechanics performance in 30-s chair stand test in patients with medial knee osteoarthritis
by Vitor Ferreira, Leandro Machado, Adélio Vilaça, Francisco Xará-Leite, Paulo Roriz
Abstract: Knee osteoarthritis (OA) is characterized by weakness and knee joint pain which may affect the performance in some activities of daily life like sit-to-stand. The aim of this study was to evaluate the strategies used by patients with knee OA when performing the 30-second chair stand test (30s-CST), and its association with their well-being. Twenty-one patients with knee OA were recruited. A 3D motion analysis system and two force plates were used to capture the kinematics and kinetics during the 30s-CST. The sit-to-stand and the stand-to-sit phases of the test were analysed independently. Significant differences were found (p < 0.05) between the first three and the last three repetitions in the 30s-CST for knee joint moment and power. No significant differences have been found between the most painful knee and the contralateral knee. The correlations found between the subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS) and biomechanical parameters were significant (p < 0.05). Patients with the best score in KOOS subscales also showed better performance in the 30s-CST. Assistive technologies that maximize biomechanical strategies could be a valuable contribution to improve the well-being of these patients.
Keywords: sit-to-stand; power; joint moment; knee; KOOS; VAS; motion analysis; performance; well-being.
Correlation between ankle stiffness and antagonist co-activation in post-stroke subjects
by Edgar Ribeiro, Augusta Silva, Liliana Pinho, Rubim Santos, Francisco Pinho, Andreia Sousa
Abstract: Tonus dysfunction has been broadly investigated in post-stroke subjects through the evaluation of muscle resistance against stretching and its characterization in a functional context is an important challenge. This study aims to analyse the correlation between intrinsic stiffness, functional stiffness and antagonist co-activation, at the ankle joint of post-stroke subjects. Both lower limbs of eight post-stroke participants were evaluated. Intrinsic stiffness was assessed during passive dorsiflexion by an isokinetic dynamometer, functional stiffness during upright standing on a force platform and antagonist co-activation was obtained in upright standing and postural phases of gait initiation and stand-to-sit through the electromyographic signal of ankle muscles. A significant positive correlation was found between antagonist co-activation of ipsilesional tibialis anterior/soleus pair in upright standing and functional stiffness (r=0.810; p=0.015; 1-?=0.899). Antagonist co-activation seems to be related to functional stiffness in upright standing, suggesting the relevance of evaluating tonus dysfunction through motor control variables obtained under functional conditions.
Keywords: Tonus; Postural Control; Movement; Ankle; Stiffness; Antagonist co-activation; Upright standing; Gait initiation; Stand-to-sit; Stroke.