AHFE Open AccessHuman Dynamics, Product Evaluation and Quality
Editors: Zhizhong Li, Matteo Zallio, Susan Xu
Topics: Human Dynamics
Publication Date: 2024
ISBN: 978-1-964867-07-6
DOI: 10.54941/ahfe1004857
Articles
Quantifying Information Dissemination: Structured Review on Methods and Variables for Sharing Behavior on Social Network Sites
The dissemination of misinformation on Social Network Sites (SNS) and the consequent emergence of radicalizing narratives present an increasingly societal problem. Empirically founded models on individual behavior of information dissemination in SNS are therefore necessary to improve our understanding of influential variables. The objective of the present research was to identify relevant variables and to provide an overview of how current research addresses the complex issue of information dissemination decision-making on SNS. To this end, we conducted a PRISMA-based structured literature review focused on variables and experimental designs used in the exploration of individuals' decision-making processes to share information on SNS. A special focus was on the usage of experimental tools that can be used for the simulation of SNS or a scenario based research approach, respectively. For our analysis we extracted 5195 articles published between 1990 and 20203, from four databases (Web of Science, PubMed, PsychInfo, Scopus) and selected them based on strict exclusion criteria like the mandatory use of empirical methods and the necessity of experimental manipulation. Those articles were reduced to 18 papers from which we extracted used variables, experimental design and the employed tools. We discuss constructs related to dissemination of false or misleading information on SNS and how they have been operationalized from previous research utilizing field theory to structure the present review.
Marvin Sieger, André Calero Valdez, Tim Schrills
Open Access
Article
Conference Proceedings
Identification of Factors for Dynamic Function Allocation from the Perspective of Human Information Processing
To ensure safe and efficient collaboration between humans and automated systems, it's essential to understand how to allocate functions dynamically. The first step involves identifying the factors that may trigger such dynamic function allocation. When factors influencing information processing emerge and reach a certain level of significance, individuals often experience changes in their states and performance. It is at this juncture that dynamic human-machine function allocation becomes necessary. Therefore, identifying these factors from the perspective of human information processing can help determine whether a task element will be affected by a specific factor and if dynamic function allocation should be initiated. By conducting an extensive literature review encompassing various related studies, this research identified factors that may impact different stages of human information processing. Subsequently, these factors were identified for dynamic function allocation in human-machine collaboration. This study is expected to provide a theoretical foundation for achieving dynamic function allocation in human-machine teaming.
Wangzhi Wang, Manrong She, Shanguang Chen, Zhizhong Li
Open Access
Article
Conference Proceedings
A Generalized Framework for Human-Machine Function Allocation
Human-machine function allocation is the process of determining how a system functions or tasks are distributed between humans and machines. Reasonable human-machine function allocation is a key factor in ensuring system safety and performance. Considering the deficiency of existing methods of human-machine function allocation, this paper proposes a generalized framework for human-machine function allocation covering the static and dynamic function allocation phases. The functional units formed by task decomposition engage in the framework as input. The function allocation solution space is first established based on the consideration of strengths and weaknesses of humans and machines and the task requirements to their capabilities. Then feasible solution space is formed in response to situational factors to implement a flexible human-machine function allocation, so as to provide more possibilities for timely and effective response to various possible safety problems. Finally, optimal solution is determined by comprehensive evaluation with trade-off criteria and relative suitability rules of humans and machines to realize safer and more efficient human-machine collaboration. In addition, the limitation and preference rules in terms of human and machine capabilities, situational feasibility rules established with situational triggering indicators, a comprehensive evaluation with trade-off criteria and relative suitability rules of humans and machines are summarized to illustrate the application of the framework.
Yanrong Huang, Manrong She, Chunhui Wang, Chao Zhu, Shanguang Chen, Zhizhong Li
Open Access
Article
Conference Proceedings
Mental Workload Prediction Method Based on GOMS
The conventional approaches to assessing mental workload with operators are time-consuming, and even more challenging when experienced operators are tougher to find. Prior to an experiment involving operators, mental workload prediction methods may be useful for having a preliminary evaluation of a system or interface. This study represented mental workload using the ratio of GOMS-based predicted task completion time to available time. The low-version and high-version maritime operation interfaces were compared. In the GOMS analysis, this study disassembled task goals based on a hierarchical structure and matched each subtask goal with a method. Given the presence of considerable repetitive GOMS operators throughout the task execution, the idea of operator sequence block was introduced for task analysis and reader comprehension. By nesting these blocks, the task was decomposed into keystroke-level GOMS operators. By accumulating the standard times of the GOMS operators, the time prediction results for operator sequence blocks, methods, hierarchical task goals, and overall task can be obtained following the bottom-up approach.The results indicated that the number of GOMS operators and the task completion time required for the operators significantly decreased when using the high-version interface. Consequently, it was anticipated that the high-version interface could notably reduce the operators’ mental workload. The mental workload prediction method based on GOMS proposed in this study can be used to guide early-stage interface design to enhance operator performance.
Wentao Li, Zhizhong Li
Open Access
Article
Conference Proceedings
Cognitive-oriented Process Information Presentation for Augmented Reality Assisted Product Assembly
The information assistance during manual assembly process of mass customization production is indispensable in order to assure the assembly quality. The complexity of searching information and difficulty of understanding information brings about cognition burdens of workers under the varied and lengthy assembly process, where augmented reality (AR) can be an effective instruction tool. The cognitive issues of AR based information presentation for assembly guidance were discussed in this paper. The work about complexity of manual assembly process was analyzed both on error prediction and AR based cognitive perspective of visual assets. A four levels hierarchical task analysis was conducted for assembly process with three kinds of assembly stages, i.e. selection, installation and inspection. Cognitive reliability and error analysis method was taken to identify the possible human assembly errors during three stages considering the human cognitive activity and function. In order to provide right information at right place and right time for decreasing the assembly errors, the often used visual assets, i.e. 3D model, 2D annotation, text and video, were discussed for conveying assembly instruction intention in AR scenario. From the authoring complexity and potential cognitive efficiency aspects, different information presentation styles for three assembly stages were described.
Junfeng Wang, Ting Shi, Hui Xiong, Lei Wu, Yufan Lin
Open Access
Article
Conference Proceedings
An Interaction Engine and Question Refactor Method in Question Answering for Knowledge-Driven Process Planning
Process planning is the intermediate stage between product design and product production. In the ever-evolving landscape of manufacturing, the optimization of process planning plays a key role in ensuring efficiency, cost-effectiveness and overall productivity. Traditional process planning methods often rely on predefined rules and expert knowledge, along with process engineers’ experiences, which are tacit and unstructured, existing in their minds. Weak optimal results and resource inefficiencies come in accordance with inefficient knowledge reuse. Existing research work has developed systematic knowledge modeling for process planning and constructed a process knowledge graph (PKG), based on which fundamental question answering (QA) has been performed. But there is the single round strategy in the process of QA over knowledge graph (QAKG). Process planners’ questions may be not parsed and they don’t have chance to implement or even don’t know what to implement. We propose an interactive QAKG framework containing the question refactor method for process planning. The interaction engine will be triggered when the input question can’t be parsed to query statement for target entities. Candidate intermediate entities are searched and listed for specifying. The initial question will be refactored after integrated with the entities selected by users. The methodology is implemented by taking the process data of CPU cooler from a manufacturing enterprise. Results show the method could promote the intelligence of knowledge-driven process planning as well as the level of knowledge acquiring and sharing.
Tianzong Yu, Yan Ma, Peihan Wen
Open Access
Article
Conference Proceedings
An Experimental Approach to Measuring Resilience Potential: Interactions in a Breakfast Cooking Task
Industrial systems that form the basis of our daily lives, such as railroads, medicine, and aviation, function as socio-technical systems with complex and large-scale characteristics. As a methodology for the safe operation of such systems, measures to enhance "resilience potential," the ability to flexibly respond to changes in circumstances, such as unexpected behavior or unknown events, are attracting attention. Through an experimental approach, this study aims to clarify what strategies and cognitive factors cause differences in performance among operators and how these differences relate to resilience potential. Furthermore, by defining the characteristics of resilient behaviors from the experimental results, we will examine interaction designs to promote these behaviors.MethodThis study focused on the relationship between non-technical skill (NTS), a general-purpose task performance skill, and resilience and formulated the following experimental hypotheses.(1) Participants with higher NTS will behave more resiliently, resulting in higher work performance.(2) When a sudden change occurs, the information and strategies used by the high NTS group will differ from those of the low NTS group.The participants in the experiment were 23 university students. They completed a questionnaire to measure NTS before the experimental tasks. In the experiment, participants were asked to play an application game that implements Craik & Bialystok's Breakfast cooking task: prepare a breakfast set (toast, fried eggs, and coffee) for the number of people ordered at any given time. Additional orders for coffee, fried eggs, and toast alone may be placed, and the task requires that all the ordered items be cooked as quickly as possible without making any mistakes. This task is characterized by the fact that only the goal to be achieved is given, and the procedures and strategies along the way are left to the participants' judgment. This is similar to the characteristics of air traffic control operations, a well-known task that requires resilience potential. The experiment consisted of five scenarios. Scenarios 1, 2, and 4 were steady-state scenarios, while scenarios 3 and 5 were emergency scenarios. In the steady-state scenario, participants were asked to operate one application, while in the emergency scenario, they were asked to perform two applications in parallel. We designed the emergency scenarios to observe the resilience potential, an adaptive response to changing circumstances where accustomed methods do not work. The measurement data were task performance, gaze data, and post-task interviews. Task performance was evaluated regarding the time required to complete the task and the number of errors.Result and DiscussionThe experimental results showed no correlation between NTS scores and work performance. Thus, hypothesis (1) was not supported. Next, we compared the gaze data of the groups with high and low NTS scores. We found several areas on the experimental screen where the gaze accumulation amount differed significantly. In particular, the group with high NTS scores looked at the work progress indicator more than those with low NTS scores. On the other hand, the group with low NTS scores saw more buttons that became active when work was completed than those with high NTS scores. Compared to the post-interview results, the high NTS score group was found to be actively managing their progress. On the other hand, the group with low NTS scores did not address their progress in detail but only checked whether the work was completed using button expressions. These results suggest that hypothesis (2) is likely to be supported.
Haruka Yoshida, Taiki Ikeda, Taro Kanno, Daisuke Karikawa, Kohei Nonose, Satoru Inoue, Takashi Toriizuka
Open Access
Article
Conference Proceedings
Understanding Chinese Adults’ Attitudes Towards IoT Home Care Technologies
Internet of Things (IoT) technology provides innovative solutions for home care. This study investigates Chinese adults’ preferences and influencing sociodemographic factors of using IoT home care technologies. A total of 512 Chinese (Mean age = 46.1 years, SD = 18.1 years) were investigated about their use and interest in 26 types of IoT home care technologies, overall willingness to use the technologies, and sociodemographic information using an online survey. Stepwise regression was used to identify predictors for ownership of IoT home care technologies and willingness to use IoT technologies. This study found that the overall ownership of IoT home care technologies was not high (Mean number of IoT technologies ‘already in use’ = 8.1 among the 26 selected technologies, SD = 5.0). Chinese users generally had a positive attitude towards such technologies. Their concern focused on home safety and health. People who were younger, more competent with housework, had a monthly disposable income of over 3000 Chinese Yuan (CNY), had more communication with neighbours, lived in a city, had better self-reported health status, lived in a villa and with Internet connection had higher overall scores for ownership of IoT technology. People with better communication skills, who were younger, lived in a city, had a monthly disposable income of 5000–10000 CNY, were more competent with housework and continued to work were more willing to use IoT home care technologies. This study helps stakeholders and policymakers understand the sociodemographic diversity the requirements for IoT home care among Chinese adults.
Runting Zhong, Saihong Han, Mengyao Ma, Yunlong Xu, Meiyu Fan, Yixuan Chang
Open Access
Article
Conference Proceedings
Evaluating the Impact of Prosthetics on Gait Symmetry in Unilateral Lower Limb Amputees
Gait symmetry is a primary criterion for assessing the rehabilitation progress of unilateral transtibial amputees with prostheses. This study aimed to examine the gait symmetry of dynamic kinematic and kinetic functions in unilateral transtibial amputees using prostheses during walking. Methods The study was approved by the University Ethics Committee and involved five (3 females and 2 males) unilateral transtibial amputees (age: (mean ± SD) 63.4 ± 7.7 years, height: 165.6 ± 6.4 cm; body mass: 69.4 ± 4.1 kg; years of using prosthetic foot: 30.8 ± 9.3 years). For collecting the kinematic and kinetic data, thirty-nine passive-reflective markers were placed on the participant according to the landmarks set of the plug-in full body model. An 8-camera motion capturing system (VICON, Nexus 2.0 Inc., Oxford, UK) and 2 force plates (AMTI, Advanced Mechanical Technology, Inc., Watertown, USA) mounted under the walkway were recorded 100 frames per second simultaneously. All the systems were calibrated before the experiment. Participants walked at their self-selected walking speeds. Based on their self-selected walking speed record, ± 10% range were calculated as the references for each participant’s fast and slow walking speed. Each participant repeated walking trials until a minimum of 5 “clean” foot force plate contact with both right and left limbs were acquired. The corresponding data from 5 gait cycles were selected to calculate the lower limb joints angles and vertical ground reaction force (GRF) during walk. Then symmetry index (SI) was calculated to provide a descriptive marker for the degree of symmetry between the intact and residual limbs. A value of SI less than 5% reflects good symmetry between the limbs, whereas increasingly positive values indicate the value for the residual limb was greater than that of the intact limb, while negative values denote that the intact limb value was greater. Results Normalized vertical GRF of two limbs increased with increased walking speeds. The corresponding SI was the largest when heel strike with slow walking speed (6.2 ± 0.8 m/s). Gait imbalance was observed during loading response and midstance (around 30% - 45% stance phase) when the walking speed was increased. While SI values of ankle angles were enlarged with increased walking speed, indicating more asymmetry of ankle angle between two limbs with their traditional prostheses when the walking speed increases. Conclusions The current prostheses can only support the basic daily activities for the unilateral transtibial amputees. The new design of prostheses should therefore focus on kinetic and kinematic parameters such as the symmetry between the residual limb and the intact limb, and energy saving for the amputees during high intensity activities.
Gaby Shi, Kit Lun Yick
Open Access
Article
Conference Proceedings
Co-Creating Public Service: Development of Hobby Voucher for Youths and Sport Clubs
The increasing sedentary lifestyle and decreased physical activity among children and youth have become a global concern. Public services, facilities and sports clubs play a significant role in supporting children's physical activity. This article describes the co-creation process of a physical activity support system - a digital tool for public financial support and management in the field of youth sport and hobbies - aiming at increasing involvement and continuation of hobbies after pandemic. We analyze the roles of stakeholders and mutually supportive ways they were involved in the co-creation process.
Kimmo Tarkkanen, Esko Halonen, Elina Kontio, Niina Katajapuu
Open Access
Article
Conference Proceedings
User's Visual Behaviour: relationships between readability, typography and background color - An Eye-tracking View
The purpose of this study is to understand the impact of black typography on coloured backgrounds, on the user’s visual behaviour to analyse which colour and opacity are the most appropriate to read black text. We recruited 20 participants (9 identify themselves as male and 11 as female) aged from 18 to 21 years old with a mean age of 19.50 (SD=1.50). All participants were tested with the same criteria and in the same environment. Data were acquired through the Gazepoint GP3 system and the incorporated Gazepoint Application Program Interface software, capable of calculating the individual’s pupillary reaction when exposed to specific colours and individuals were subject to observation of an experimental protocol, with just 2 minutes. We used the colour setting CMY (cyan, magenta and yellow) to analyse two variables: 1) colour used as background; 2) background opacity. The first consists in the changing of the background colour over black text between the colours, yellow, magenta and cyan. The second variable consists in analysing how the change in the opacity of the background affects the reading and the user’s perception, varying the opacity percentage between 100, 50 and 25. All possible combinations (9) of coloured backgrounds were tested, to avoid inaccuracies in data analysis and processing. The typography used was Arial, the font size was 20pt and the colour was black.Through analysing and processing the data provided by the eyetracker, we were able to conclude that 100 percent opaque colours make it more difficult to read black typography. The light intensity of these colours stimulates the participant’s pupil to contract. This discomfort allows us to conclude that choosing yellow, magenta and cyan, with 100 percent opacity, is not the best combination for reading black text.We concluded also that the pupil dilates with reduced light intensities, such as 25 percent opacity. The pupil is in a state of rest when it is not subjected to extreme light stimuli (excessive and reduced), reaching an intermediate size. This happens with backgrounds at 50 percent opacity, which makes reading easier and more fluent.The pupil reaches a state of rest when not subjected to extreme light stimuli, whether excessive (too much light) or reduced (lack of light). Therefore, we can conclude that, regardless of the preferred colour, reading typography in black is more pleasant on backgrounds with opacity between 25 percent and 50 percent.Finally, it is important to highlight that the pupil is constantly adjusting to the environment exposed. The pupillary reaction can be influenced by other external factors, such as the surrounding lighting conditions and everyone’s sensitivity.
Eduarda Soares, Ines Soares, Quina Coelho, Ricardo Almeida, Rita Fernandes, Ana Teixeira, Sonia Brito-costa, Silvia Espada, Maria Antunes
Open Access
Article
Conference Proceedings
'The readiness of the elderly for autonomous vehicle technology: An integrated review
Currently, an increasing number of drivers are facing challenges associated with the decline in physical function as they age. The widespread adoption of autonomous vehicle technology holds the promise of addressing travel difficulties for older adults. However, older adults encounter difficulties in using autonomous vehicle technology due to their declining physiological conditions and cognitive abilities. Therefore, this paper aims to understand the readiness of older adults for autonomous vehicle technology. The paper applies Human Readiness Level (HRL) to discuss the performance of older adults using three specific autonomous vehicle features—Adaptive Cruise Control (ACC), Blind Spot Warning (BSW), and Lane Departure Warning (LDW). Employing a literature review approach, this paper conducts database screening on the research topics evaluating the readiness and driving performance of older adults for autonomous vehicle technology with the application of HRL and related theories. In total, 15 articles were selected as core literature. We propose recommendations and measures on how to enhance the readiness of older adults for autonomous vehicle technology from both technological and individual perspectives to enhance the readiness of older adults for autonomous vehicle technology and ensure safer travel for them.
Teng Wang, Yunshan Jiang, Yanling Zuo, Peggy Wang, Jia Zhou
Open Access
Article
Conference Proceedings
Consumer acceptance of grass ingredients in human diets
Grass has the potential to play a pivotal role in shaping sustainable diets as novel food technologies are exploring its use in human diets. By embracing unconventional yet nutritious sources like grass, we can mitigate the environmental impact of traditional agriculture while promoting healthy diets and supplying adequate nutrition. This research aims to explore the acceptance of grass in human diets through a quantitative analysis of consumer acceptance. 485 respondents were sampled for the study. The results suggest a positive response to grass-derived ingredients with a 3.58 mean score for their acceptance in human diets. Attitude, safety and preparedness, willingness, and readiness to try foods with grass-derived ingredients were significant factors influencing the acceptance of grass-derived ingredients in human diets. The positive results encourage the exploration of novel food sources to tackle emerging environmental issues and further suggest improving individual attitudes through strategic product design and marketing to encourage open-mindedness which drives consumer acceptance and willingness to include grass-derived ingredients in human diets.
Anne Mumbi, Helen Pittson, Frank Vriesekoop, Sebnem Kurhan
Open Access
Article
Conference Proceedings
3D Numerical Simulation for Thermal Protection of Phase Change Material-Integrated Firefighters’ Turnout Gear
Firefighters often work under dangerous and harmful conditions, which could cause unexpected accidents, injuries, and deaths. There were 19,200 injuries that occurred on the fireground in the United States in the year 2021, and more than 10% of these injuries were caused by burns and thermal stress [1]. The current NFPA 1971 (Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting) requests that firefighters’ turnout gear textiles meet the minimum requirement of a thermal protective performance (TPP) rating of 35, equating to 17.5 seconds until second-degree burns occur in a flashover situation [2]. Notably, exposure to a high-temperature environment could be much longer than a few seconds when firefighters conduct rescue tasks at a fire scene. Hence, research is needed to explore novel turnout gear technology that can significantly enhance thermal protection for firefighters. Phase change materials (PCMs) can absorb large amounts of latent heat while maintaining a constant melting temperature. We use this phenomenon to incorporate PCM into turnout gear to enhance the TPP. Numerical simulations were performed in this work which can guide future experimental design and testing to save time and effort. Currently, a three-dimensional (3D) turnout gear-equipped human thermal model is unavailable. Therefore, this work is the first 3D numerical study to explore (1) the thermal protection improvements of firefighters’ turnout gear by using PCM segments under flashover/explosive and hazardous conditions, and (2) the minimum amount of PCM required to enhance the thermal protection without significantly increasing the weight of firefighters’ turnout gear. Methods3D heat transfer simulations were performed through COMSOL Multiphysics (COMSOL, Inc., Burlington, MA 01803, USA). To maintain firefighters’ activities and movements in the fire scene, PCM was broken down into several segments to cover the main body but avoid joints. The blood circulation effect in the body was considered as a bioheat source in the model. The equivalent heat capacity method was used to simulate the phase-changing process. The heat flux applied at the outer surface of turnout gear (mimicking combined radiant and convective heat sources at the fire scene) was 83 kW/m2 for flashover/explosive conditions and 8.3 kW/m2 for typical hazardous conditions according to the current NFPA 1971 standard [2,3]. Various PCM segment thicknesses were studied to determine the minimum amount of PCM required to achieve sufficient thermal protection.ResultsThis study found that the 3.0-mm-thick PCM segments with a melting temperature of 60°C can extend the time for the skin surface to reach second-degree burn injury (60°C [3]) by 18 seconds and 52 seconds under flashover/explosive and hazardous conditions, respectively. Moreover, thinner PCM segments, i.e., 1.0-3.0 mm thickness, could also remarkably mitigate the temperature increase on the skin surface while reducing the added weight of turnout gear.ConclusionThe PCM segments could increase the time for the skin surface to reach second-degree burn injury by around 2.0 times compared to conventional firefighters’ turnout gear with no PCM. The 3D modeling results can be used to develop a next-generation firefighter turnout gear technology. DisclaimerThe findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC). References[1] Campbell, R., Hall, S., United States firefighter injuries in 2021, NFPA Res. December 2022. [2] NFPA 1971, Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting, 2018.[3] Coletta, G.C., Arons, I.J., Ashley, L.E., Drennan, A.P., 1976. The Development of Criteria for Firefighters' Gloves Volume II: Glove Criteria and Test Methods, Contract No. CDC-99-74-59, February 1976.
Susan Xu, Jonisha Pollard, Weihuan Zhao
Open Access
Article
Conference Proceedings
Impact of Self-Contained Breathing Apparatus (SCBA) Weights on Firefighter’s Kinematics During Simulated Firefighter Tasks
Firefighters face a multitude of hazards in their line of duty, with overexertion being the foremost cause of injuries or fatalities, as referenced in studies [1, 2]. This high risk is often amplified by the physical demands of their role, further exacerbated by the burden of carrying heavy SCBA. The objective of this research is to examine how the weight of SCBA affects the musculoskeletal joint movements of firefighters. There is an urgent requirement for precise measurement and analysis of firefighters' movements to understand the impact of SCBA weight on both performance and injury risk. Traditional motion capture techniques, which are primarily optical-based or inertia-based, have their limitations, such as marker obstructions due to clothing or lower accuracy and drift issues. To overcome these obstacles, this study introduces a groundbreaking hybrid motion capture technique, combining the advantages of both existing methods. This new method is expected to offer a detailed and accurate evaluation of how SCBA weight influences the kinematics of firefighters.MethodsIn this study, six professional firefighters (average age: 34.2±5.2 years) were involved in performing four simulated tasks: stair climbing, searching, hose advance, and overhaul, under three different SCBA weight scenarios: only gear, gear with a standard 45-minute SCBA, and gear with an SCBA plus an additional 10 lbs (SCBA-10). Data collection included optical markers on key equipment like helmets, boots, and gloves, 17 IMUs, EMG, pressure insoles, and a metabolic mask. A novel hybrid inverse kinematics method, blending IMU data with optical markers, was utilized to minimize drift errors and precisely reconstruct joint movements. Joint angle data, particularly for hose advance and overhaul, were segmented and normalized for comprehensive statistical analysis. Preliminary Results and DiscussionInitial analysis of data from two human subjects showed that heavier SCBA weights led to increased hip joint movement during stair climbing, with a noticeable 10% increase in hip angle range under the heaviest SCBA condition (SCBA-10). In hose advance tasks, firefighters showed less lumbar extension with SCBA, indicating a preference for using arm movements over the back and torso to maneuver the hose. Traditional inverse kinematics with only markers showed significant errors in joint angles, especially in pelvic tilt and hip flexion, which were effectively corrected with the new hybrid method. This innovative approach allows for a more precise evaluation of the effects of SCBA weight on firefighter kinematics and musculoskeletal load. Additional data is expected soon, which will provide a greater understanding of the effects of SCBA. While our current analysis is based on a small sample, we expect that expanding the study to more participants will reveal further kinematic changes due to loading.Preliminary Conclusions To the best of our knowledge, this research represents the first endeavor to precisely record the movement of firefighters engaged in activities while fully equipped with gear and SCBA using both inertia and optical motion capture systems. Our initial findings validate this method and suggest its potential to refine SCBA weight standards based on scientific evidence. We noted that SCBA's weight substantially modifies the movement patterns of firefighters, possibly increasing musculoskeletal strain. This research paves the way for future dynamic analyses and contributes significantly to understanding how SCBA weight impacts musculoskeletal health, ultimately provide the possibility of recommending SCBA weight limits for injury prevention.DisclaimerThe findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC).References[1]M. M. Alemi, J. Geissinger, A. A. Simon, S. E. Chang, and A. T. Asbeck, "A passive exoskeleton reduces peak and mean EMG during symmetric and asymmetric lifting," Journal of Electromyography and Kinesiology, vol. 47, pp. 25-34, 2019.[2]M. J. Karter, "Patterns of firefighter fireground injuries," National Fire Protection Association, 2014.[3]S. Wang, C. Feng, X. Chen, M. Shan, and W. Niu, "A biomechanical evaluation of firefighters’ musculoskeletal loads when carrying self-contained breathing apparatus in walking and running," Journal of Safety Research, 2023.
Susan Xu, Rachel F Jones, Neethan Ratnakumar, Kübra Akbaş, Jeffrey Powell, Ziqing Zhuang, Alex Zhou
Open Access
Article
Conference Proceedings