AHFE Open AccessPhysical Ergonomics and Human Factors
Editors: Luximon Ameersing, Shuping Xiong
Topics: Physical Ergonomics and Human Factors
Publication Date: 2025
ISBN: 978-1-964867-61-8
DOI: 10.54941/ahfe1005996
Articles
Combatting the Heat: Assessing Heat Stress Risks in Aircraft Maintenance Environments
Aviation maintenance is a critical element to the success and safety of air transportation sector. Professionals in this field face several hazards associated chemicals and thermal exposure. Such a hazard can lead to serious incidents, including catastrophic aircraft accidents. Consequently, the implementation of appropriate hazard controls measures is vital not only for the prevention of workplace injuries and illnesses but also for promoting comfort and efficiency of aviation technicians. A major challenge in tropical regions is the heat exposure. Aviation maintenance facilities located in these hot climates face significant difficulties due to high temperatures and increased thermal loads during work. Extended exposure to heat stress can result in severe health issues in addition to causing physical fatigue and cognitive decline. Such effects can impair a mechanic's capacity to execute tasks safely and accurately, thereby increasing the risk of errors that could lead to fatal accidents. This study aims to investigate the effects of heat stress on aviation mechanics working in a tropical area and to propound innovative engineering and administrative controls to mitigate the impact of this factor on aviation mechanics. The primary research question focuses on whether aviation mechanics working in smaller hangars in tropical regions face an elevated risk of heat-related injuries.The assessment of heat stress risk was conducted in a flight maintenance hangar located in Florida, USA. During the assessment period, 18 full-time aviation mechanics were engaged in day shifts to complete both scheduled and unscheduled inspections and maintenance on various single and multi-engine aircraft. Environmental monitoring was performed using the REED R6200 WBGT Heat Stress Meter (Wilmington, NC, USA). Comparative analyses were performed across different sections of the hangar to identify hotspots and trends related to heat stress risk. The collected data was then compared to the Threshold Limit Values (TLV) established by the American Conference of Governmental and Industrial Hygienists (ACGIH) to determine if the measurements fell within acceptable limits.The investigation into heat stress within the targeted aviation maintenance hangar determined that the average Wet Bulb Globe Temperature (WBGT) was recorded at 27 ± 0.8 °C. This measurement is nearly aligned with the Threshold Limit Value (TLV) for heat stress established by the American Conference of Governmental and Industrial Hygienists (ACGIH), which is 27.5 °C. Considering a metabolic workload of 415 Watts, this WBGT suggests that aviation mechanics in this setting face a high risk of heat-related injuries. ACGIH guidelines recommend that under such strenuous conditions, a work/rest schedule comprising 50% work and 50% rest each hour should be adopted to effectively mitigate heat stress. Furthermore, certain sections of the hangar were identified as excessively hot, necessitating that work in these areas be restricted unless substantial engineering controls are implemented.The results indicate the urgent need for intervention to mitigate heat stress within the hangar environment. The recorded Wet Bulb Globe Temperature (WBGT) levels, in conjunction with the significant workload, indicate that workers are under potentially dangerous work conditions. To protect workers' health and prevent heat-related illnesses, it is essential to follow the recommended work/rest regimens and implement robust engineering controls. Such strategies may involve enhancing ventilation, deploying cooling systems, or modifying work hours to circumvent the peak heat times of the day.The study emphasizes the necessity of implementing proactive strategies for the management of heat stress. The current conditions, which approach the limits of safe working conditions, highlight the critical need for continuous monitoring and refinement of heat stress management protocols. By addressing these challenges, it is feasible to mitigate the likelihood of heat-related injuries and enhance a safer working environment for aviation mechanics, both in the short term and during peak heat seasons. This strategy not only protects the health of workers but also reduce the likelihood of errors which can lead to aviation disasters.
Ali Aljaroudi
Open Access
Article
Conference Proceedings
Influence of Footstep Sounds Induced by Varying Shoe Types and Gait Frequencies on Initial Impressions
With the rapid development of multimedia industries such as film, television, and gaming, the role of sound in shaping environmental atmosphere and character imagery has garnered increasing attention. Particularly, footsteps have been the focus of interest due to their unique role in identity recognition and emotional expression. Although existing research has concentrated on simulating realistic footstep sounds and analysed their acoustic characteristics, there is a relative scarcity of studies on how footstep sounds influence initial impressions on others. This study aims to fill this gap by exploring the impact of different footstep sounds on personality impressions. We designed a total of eight footstep sounds based on four types of footwear (heels, work boots, sneakers, and leather shoes) and two walking frequencies (0.75 seconds and 1 second between steps), and invited 60 subjects with normal hearing to evaluate these footstep sounds across 15 impression dimensions. The results indicate that heels footsteps convey a sense of charm but lack stability; work boot footsteps give a lower sense of charm and a stronger impression of dominance; sneakers produce a similar effect to work boots but with a weaker impact; and leather shoes convey a certain level of charm. This study not only provides new perspectives and data for the field of psychoacoustics but also has guiding significance for character imagery and environmental design in film production, game design, and virtual reality.
Qihan Sun, Lu Chen, Minshi Fu, Linzi Chang
Open Access
Article
Conference Proceedings
Effects of the Global Pandemic on indoor air quality in dental surgeries: Evaluating practical alternatives to current guidelines and regulations in Scotland.
The COVID-19 pandemic focused attention on the role of ventilation on improving indoor air quality to mitigate against the risk of spread of infection. The aim of this study was to evaluate the effectiveness of increased ventilation and explore an alternative solution for improving indoor air quality to mitigate the risk of airborne infection in dental surgeries. Dental surgeries present a specific risk of airborne infection due to the bio-aerosols generated by high-speed dental instruments such as drills and air-water syringes. Studies show that particulate matter, volatile organic compounds, and carbon dioxide levels often exceed recommended thresholds during dental procedures, contributing to poor indoor air quality and increased health risks. To mitigate these risks, regulatory bodies recommended increasing air changes per hour to 10-12 in dental surgeries. Implementing such systems poses significant physical, financial, and regulatory challenges, alongside ongoing high energy consumption costs. The study evaluated the rapid changes to the requirements and guidance to avoid the risk of airborne infections in dental surgeries during the COVID-19 pandemic. A prototype for an at-source aerosol extraction device was developed and tested in a live dental surgery using an air quality monitor to determine if it could effectively remove aerosols at-source. The prototype was an articulated hose with nozzle positioned close to the patient’s mouth and connected to the existing surgery suction pump, which aspirates fluid during dental procedures. Air quality was monitored in the dental surgery during similar aerosol-generating procedures with 10 air changes an hour and then using the aerosol extraction device. The test results indicated that this alternative strategy performed better than providing 10 air changes an hour with the average of particulate matter of 1µg, 2.5µg, 4µg and 10µg recording an average concentration of 0.19mg/m3 compared to 0.33mg/m3 when using 10 air changes per hour. These results demonstrate that an at-source extraction device could provide a viable alternative to high ventilation strategies. In conclusion, this study demonstrates that an at-source extraction device could mitigate against airborne infections in a cost-effective and energy efficient manner. Further testing, including larger sample size and computational fluid dynamics modelling, is needed to refine the design and assess its applicability across different dental settings. This research provides an opportunity for revising existing guidelines and explore alternative indoor air quality management solutions that ensure both practitioner and patient safety.
Ainslie Scott, Quazi Zaman
Open Access
Article
Conference Proceedings
Sensory Perception of Surface Textures in Handheld Operational Products: A Case Study of E-Bike Handgrips
Handheld operational products including bicycles, e-bikes, and other personal mobility devices, the grip and tactile perception between users' hands and the product’s handle have a direct impact on safety, comfort, and psychological state. Given the widespread popularity of e-bike in the short-distance travel, it is essential to investigate whether specific surface texture can enhance anti-slip performance, comfort, and emotional stability under different usage contexts. By systematically analyzing e-bike handgrips, this study provides practical design insights that can be extended to a wide variety of handheld operational products, ultimately contributing to improved user experience and safety.A mixed-method approach was employed, integrating both subjective and objective data. Three representative e-bike handgrips textures-smooth, concave, and convex-were selected. Twenty volunteers were recruited for two experimental sessions: i) Participants performed a simulated riding task under normal and slippery conditions. A seven-point Likert scale gathered subjective feedback on comfort, visual impressions, and anti-slip performance. Meanwhile, electromyography (EMG) recorded grip force to quantify the force levels associated with each texture; ii) Participants first watched an e-bike accident video to elicit an emotional response. They then completed a short real-world driving task using each of the three handgrips. During this session, galvanic skin response (GSR) was monitored to capture fluctuations in emotional arousal, and brief interviews before and after provided additional qualitative insights into user experience and perceived safety. User-reported experiences differed markedly among the three handgrip textures. Convex handgrips generally fostered stronger feelings of security and reduced perceived force, particularly in slippery conditions, where users noted enhanced control. Concave handgrips were consistently praised for long-term comfort, as participants felt less fatigue during extended grip scenarios. Smooth handgrips, while sufficient in stable conditions, tended to elicit uncertainty and higher perceived exertion when surfaces were wet. Observational notes and interview transcripts suggest that users’ emotional stability and confidence improved most with the convex texture, indicating a potential link between tactile cues and perceived safety.Overall, each texture delivers distinct advantages: convex surfaces improve anti-slip properties and user confidence, concave grips enhance comfort over longer duration, and smooth surfaces suffice in ideal settings but may underperform when heightened grip stability is required. For handheld products requiring high grip security, convex textures appear preferable, whereas scenarios emphasizing prolonged comfort may favor a concave design. These insights demonstrate the importance of nuanced surface features in shaping user perceptions and experiences. Future research can investigate variations in concavity and convexity depth, as well as diverse user demographics and additional physiological metrics, to refine texture-based design strategies. By integrating these user-centered findings into product development, designers and engineers can more effectively meet the functional and emotional needs of individuals across various handheld operational contexts.
Si Chen, Yuanyuan Liu
Open Access
Article
Conference Proceedings
Effects of different humidity levels on the human body in a high-temperature environment at high altitude
Workers in high-temperature, high-humidity, and low-oxygen environments face multiple environmental stressors, leading to increased blood circulation, changes in metabolic heat production, elevated heart rates, and reduced nerve sensitivity. These factors may contribute to a significant heat stress on the body, which directly reduces physical work capacity and impacts overall performance.As society advances, greater emphasis is placed on the safety of human factors, particularly in the most challenging work environments involving high temperatures and humidity at high altitudes. This issue has garnered significant attention. Previous studies mainly focused on one specific aspect, such as the impact of high-temperature environments on the human body. To address the need for comprehensive research on human factors in complex working conditions, this study aims to investigate thermophysiological indicators of the human body under high-temperature, high-humidity, and low-oxygen conditions. The findings will serve as a reference for improving human safety and ergonomic standards in challenging environments.METHODS: To enhance current protective measures and reference standards for specialized work and mitigate risks to human health, this study examined the effects of varying humidity levels on body surface temperature and humidity under 40℃ conditions at simulated 3000 meters above sea level. Eight participants (four males and four females) sat in a high-temperature chamber at high altitude with humidity levels of 30% and 60% for 40 minutes. During this period, body surface temperatures and humidity of seven different body segments, including forehead, chest, back, upper arm, hand, thigh and calf, were recorded using button-temperature sensors, while participants completed subjective scales.The temperature and humidity of body surface at each measured segment were linearly fitted to time to determine the correlation between these variables and time. Paired T-tests were conducted on the temperature and humidity of body surface at each 5-minute interval compared to the initial values to assess the stability. Independent T-tests were performed to compare the temperature and humidity between male and female groups at each time interval for different ambient humidity levels to identify gender-based differences. Additionally, independent T-tests were used to evaluate the effect of ambient humidity on the temperature and humidity of each body segment for both genders.RESULTS & CONCLUSIONS: Statistical analysis indicated that temperature and humidity levels varied across different body segments over time under two ambient humidity conditions. Body surface humidity showed significant differences based on body segment but was less influenced by temperature changes. Additionally, gender differences were observed. Females exhibited higher and more variable body surface temperatures compared to males in both ambient humidity conditions, while trends in body surface humidity over time differed between genders. Overall, the small-sample study in this research suggests that the design of protective clothing should incorporate breathable and moisture-absorbing fabrics tailored to specific body areas, while should also consider gender-specific requirements. Besides, the weak correlation between subjective thermal comfort ratings and body surface temperature and humidity indicates that the current indicators are insufficient to fully represent human thermal comfort in such environments, and more comprehensive or combined indicators are needed.
Qing Zhang, Mengxiong Ye, Shaojun Cai, Changhua Gao, Peng Yu, Jiachen Nie, DING Li, Qing Yang
Open Access
Article
Conference Proceedings
Ergonomic Analysis of drilling hammers in granite mining
The ergonomic risks of workers' activity, known as hammering, in the rock drill that uses pneumatic tools with drilling bits in granite mining, are a matter of concern. The hammers' activity demands excellent physical effort with transport and handling the heavy rigs with drilling bits varying from 0.40 m to 6.40 m long, weighing up to 24.250 kg. It intends to identify the main postures adopted by the hammers during their eight-hour daily shifts. Using WinOWAS, the severity of acquired posture is assessed in the execution of labor activity. Handling heavy tools, inappropriate postures, drilling activities, and cutting granite blocks while standing can develop musculoskeletal lesions in workers. Postural correction is necessary and indicates the urgency of new studies and technologies for pneumatic drilling rigs.
Thalmo Coelho, Antonio Xavier, Norma Pinto, Kazuo Hatakeyama
Open Access
Article
Conference Proceedings
Identification and Empirical Investigation of Movement Strategies for Workstation Design
This study investigates movement strategies in assembly workstations to improve ergonomic design. Movement strategies, defined as sequences of actions performed repeatedly by specific groups in specific situations, have been understudied in assembly contexts. An inductive approach was used to build a theoretical base that included knowledge, unconscious actions and hand dominance. Twenty participants performed standardized assembly tasks in standing and sitting positions, with hand and leg movements observed and qualitatively analyzed. Results revealed primary, secondary and individual movement strategies, such as right-handed participants consistently grasping objects from the right side. Future research will investigate the transferability of the identified strategies to virtual reality environments, extending their application to virtual ergonomics and simulation-based workstation design. This study contributes to the growing body of knowledge in human factors and ergonomics and provides a novel approach to optimizing human-centered manufacturing environments.
Stefan Pfeffer, Laura Lange, Katharina Gleichauf
Open Access
Article
Conference Proceedings
Influence of workstation design on intra-rater reliability in sculpting kneading task assessments
Intra-rater reliability is a crucial metric for evaluating the consistency of ratings made by the same individual across repeated trials. This study examines intra-rater reliability for posture assessment during a kneading sculpting task on worktables titled at 0° and 25°, and analyzes how table tilt and other factors affect the evaluation consistency. Thirty-nine experienced sculptors performed the tasks under both conditions in a randomized sequence. One rater assessed upper arm, lower arm and wrist postures across three trials. Postures were assessed using the Rapid Upper Limb Assessment method. Reliability and performance differences using the two table tilts were analyzed using Weighted Cohen’s Kappa coefficient (WCK), Wilcoxon signed-rank test, and Bland-Altman plots. Results showed high intra-rater reliability, with WCK averages of 0.78 (0° tilt) and 0.85 (25° tilt). Bland-Altman plots indicated strong agreement, with mean differences near zero and slightly narrower limits of agreement for the 25° tilt, suggesting greater consistency. Minor systematic bias appeared under the 0° tilt, likely due to higher ergonomic demand. The Wilcoxon test revealed significant differences in posture scores between trials for both tilts (p<0.05). These findings underscore the impact of workstation design on intra-rater reliability, highlighting the value of ergonomic integration in manual tasks. Reliability remained high across tilts, with slight variations linked to ergonomic factors. Future studies should include diverse participants, inter-rater comparisons, and varied task types to strengthen generalizability across manual work scenarios.
Patricia Eugenia Sortillon González, Aide Aracely Maldonado Macias, David Saenz Zamarrón, Juan Luis Hernández Arellano, Enrique Javier De La Vega Bustillos
Open Access
Article
Conference Proceedings
Advancing Research on Workers’ Fatigue in Construction: A Cluster-Based Review
Workers’ fatigue research in the construction industry has advanced significantly with growing attention on the physical and mental aspects and their impacts on safety and health. As construction sites adopt more digital and sensor-based technologies, this study conducts a cluster-based review to highlight how fatigue detection has evolved into an advanced stage, featuring adaptive modeling, biochemical sensing, and artificial intelligence (AI)-driven prediction tools. Using VOSviewer bibliometric analysis, this review mapped the thematic structure of recent fatigue research and identified four key clusters: psychological health, cognitive-task performance, ergonomic and occupational risks, and physical health promotion. This cross-disciplinary approach merges physiological data analysis, AI, and construction ergonomics to provide practical insights for researchers and practitioners. Key recommendations include the need for large-scale field validation, multimodal sensor integration, and user-friendly wearable systems. Overall, this review consolidates current knowledge and outlines future directions to improve safety and resilience in construction environments.
Rezaul Karim, Xingzhou Guo, Hongyue Wu, Manik Barman
Open Access
Article
Conference Proceedings
Epidemiology-Based Risk Quantification: Transitioning from the 80's and 90's Ergonomic Analysis Tools
Technology to capture postures and movements has advanced over the past two decades and has become more affordable and accessible. However, in many instances we are plugging that data in to analysis tools that were developed in the 80’s and 90’s. In this presentation we will discuss the misperceptions and limitation of many traditional ergonomic analysis tools. We will explore a more current and epidemiology-based approach to defining and quantifying ergonomic risk factors and the development of musculoskeletal injuries. We will discuss essential components of the next generation of ergonomic analysis tools and how they can be applied to advancing technology.
Mark Heidebrecht
Open Access
Article
Conference Proceedings
Standing Balance After Whole-Body Vibration Exposure: Differences Between Tiptoeing and Flat-foot Standing
Slip, trip, and fall accidents are among the most significant occupational hazards in the land transportation industry. These incidents are assumed to be associated with whole-body vibration (WBV) exposure during vehicle operation. Considered the nature of work postures in this industry, it has suggested that tiptoeing postures may contribute to fall accidents. Thus, this study aimed to investigate the effects of WBV exposure on standing balance ability when assuming a tiptoeing posture or flat-foot standing posture.A laboratory experiment was conducted with five participants to investigate the impact of WBV exposure. The participants underwent a 60-minute virtual driving session using a driving simulator (DS) while being exposed to WBV. Standing balance measurements were performed at four time points: before WBV exposure, immediately after exposure, 2 minutes after exposure, and 4 minutes after exposure. The experimental conditions included two variables: (1) the presence or absence of driving tasks during WBV exposure and (2) two standing postures for balance assessment: flat-foot standing posture and tiptoeing posture. Additionally, a control condition without WBV exposure was included, resulting in a total of six experimental conditions.Following the experiment, standing balance was evaluated using three key parameters: total center of pressure trajectory length (LNG), enveloped area (ENV_AREA), and root mean square area (RMS_AREA). The results indicated that, in the tiptoeing posture, all balance parameters exhibited significantly greater values compared to the flat-foot standing posture. This finding suggests that the tiptoeing posture inherently results in reduced balance stability.Furthermore, an analysis of WBV exposure conditions revealed that standing balance was affected compared to the control condition. In particular, a notable degradation in standing balance was observed under the driving condition. A possible explanation for this finding is that prolonged driving requires continuous operation of the accelerator pedal, using the right leg. This asymmetric muscle activation may lead to differential fatigue between the right and left lower limbs, thereby contributing to increased postural instability immediately after driving.These findings suggest the critical importance of post-driving recovery time. The results show that tiptoeing immediately after prolonged driving causes a high risk of falls and should be considered a hazardous condition. Therefore, sufficient rest time should be implemented to mitigate this risk. Moreover, given that standing balance capacity is generally lower in the tiptoeing posture compared to the flat-foot standing posture, workers required to perform tasks in a tiptoeing position should exercise caution to prevent slip, trip, and fall accidents. This study provides valuable insights into occupational safety in the land transportation industry and highlights the necessity of implementing preventive measures against fall-related accidents. Future research should further explore the physiological mechanisms underlying postural instability following WBV exposure and prolonged driving, as well as the development of effective interventions to enhance worker safety.
Junya Tatsuno, Setsuo Maeda
Open Access
Article
Conference Proceedings
Posture analysis of a TV broadcast cameraman: a case study
The work of a cameraman has ergonomic challenges which require care. A long-standing posture, peculiar of the task, along with the used camera equipment may result in the development of muscle fatigue that may cause musculoskeletal disorders over time. Aim of the paper is a posture analysis assessment of the biomechanical overload risk of cameramen's work in live broadcast television and to suggest potential solutions to risk reduction. In our case study, during the activity, the cameraman monitors the filming through a screen not adjustable in the upper body of the camera. The live television broadcast lasted 150 minutes, with 6 advertising breaks of 5 minutes each. We made video recordings of the task highlighting as the posture adopted could be classified as static and, thus, evaluated according to ISO standard 11226. Alongside this, we have also analyzed the posture with the 3DSSPP software (v. 7.1.3), allowing us to calculate, the maximum static holding time in which the worker can adopt the reconstructed posture before muscular fatigue occurs.The postural analysis of both trunk and legs showed no critical issues. Different results, instead, for both upper limbs and the neck. Throughout the task, the worker has a neck extension of 37°. According to ISO 11226, the neck posture belongs to the ‘not recommended’ area. Both shoulders were abducted (29° the right limb; 23° the left limb). This posture, based on the software's mathematical model, could be adopted with no support by the 5th percentile workforce for up to 4 minutes.Our evaluation, in this case, highlighted a crucial issue concerning screen height, which is above the eye level forcing the worker to extend the head for up to 40 minutes continuously. This is well above the 435s exposure time that 3DSSPP software calculates that muscle fatigue in the neck can occur for the 50th percentile of the working population. Besides, the ISO 11226 standard does not recommend neck extension, which was 37° in our 3DSSPP reconstruction. A simultaneous abduction of both shoulders to move the camera, although worker partially releases weight on the camera dumbbells, also contributes to overloading the neck joint. Placing the display on the back of the machine body, and adjusting its height, should allow workers to have a more neutral posture during activity. Our paper only refers to the camera model we observed; different camera could result in other conclusions. In future, we plan to further investigate this task by means of the muscle fatigue analysis using surface electromyography to assess through the time-varying median frequency.
Alessio Silvetti, Dimitri Mandolesi, Tiwana Varrecchia, Giorgia Chini, Alberto Ranavolo, Cristina Chieffo, Adriano Papale
Open Access
Article
Conference Proceedings
The Biomechanics and Epidemiology of Shoulder Injuries: Quantifying the Risk Accurately
The shoulder is a very complex joint and there are many misconceptions regarding the shoulder and the risk of injury in the industrial setting. In this presentation we will breakdown the fundamental motions and biomechanics of the shoulder. Because of the complex nature of the shoulder, many ergonomic risk factors affecting the shoulder go undocumented. Most traditional ergonomic assessments neglect to accurately quantify the risk of shoulder injury. After discussing the biomechanics of the shoulder, we will explore epidemiology research regarding the risk of shoulder injuries. We will also discuss techniques that can be used to accurately quantify the risk of shoulder injuries in the industrial setting and ways to mitigate risk.
Mark Heidebrecht
Open Access
Article
Conference Proceedings
Assessing the Impact of Backpack Carrying Styles on Users’ Discomfort
The increasing awareness about the impact of backpack usage on musculoskeletal health, particularly the spine and associated muscles, has driven research on how different carrying styles, like single-strap and crossbody, contribute to users’ discomfort. This study preliminarily examined the discomfort experienced by college students using various school bag-carrying methods and the role of chest and waist straps in optimizing load distribution and reducing discomfort. The study used a controlled treadmill walking test to evaluate users’ discomfort across three carrying configurations: one-strap, two-straps, and four-straps. Four participants without any history of musculoskeletal issues walked on the treadmill under these three scenarios, each carrying a load equivalent to 15% of their body weight. Discomfort was measured on a scale from 0 to 10, ranging from no discomfort to unbearable discomfort for key body areas such as the neck, upper back, lower back, right shoulder, left shoulder, knee, and ankle. A standardized questionnaire was used to record discomfort, ensuring an objective assessment of the load’s influence on each participant. The results showed that the carrying method affected discomfort levels. Participants experienced substantial discomfort with the one-strap configuration due to the uneven distribution of the load, while the two-straps configuration provided more comfort due to better load distribution across both sides of the body. However, the four-straps configuration offered the most effective load distribution, minimizing muscle strain and discomfort compared to the one-strap and two-straps configurations. These findings are crucial for promoting the design and use of ergonomically enhanced backpacks for college students, especially in settings where heavy loads are frequently carried while promoting better postural stability.
Md Mahabub Hasan, Nadia Islam Tanha, Sayeda Sufia Sumi, Kazi Saiful Islam, Yueqing Li
Open Access
Article
Conference Proceedings
Influence of Computer Keyboard Slope and Wrist Support Height on Users’ Discomfort
Modern workplaces rely highly on computers, making ergonomic setups essential to prevent musculoskeletal disorders like carpal tunnel syndrome. This study examined the effects of keyboard slope (0° vs. -13°) and wrist support height (9.8 cm vs. 15 cm) on wrist comfort during typing. Ten university participants took part in the experiment.The study found that a flat keyboard slope of 0° with a wrist support height of 9.8 cm provides the most comfort for wrists and forearms. However, increasing the wrist support height to 15 cm significantly increases discomfort, particularly in the neck and shoulder. The negative slope of the keyboard reduces the extension of the wrist and increases pressure on the carpal tunnel, which is beneficial.These results indicated the necessity of individually adapted ergonomic settings regarding keyboard slope and wrist support height for optimal comfort while minimizing health risks. Such adjustments may help the user to reduce discomfort and minimize the possibility of MSDs. Further research might be directed toward investigating other slope and height combinations with effects calculated both based on surveys and EMG data, which would help create better ergonomic solutions for a variety of typing styles and working environments.
Sheikh Fuzael Rahman, Md Shahnur Alam, Safaul Islam Rohan, Yueqing Li
Open Access
Article
Conference Proceedings
Epidemiology-Based Ergonomic Analysis for Data Driven Decisions
Epidemiology is the study of factors that determine the occurrence and distribution of disease in a population. In epidemiology, risk is defined as the proportion of people who are unaffected at the beginning of a study period, but who experience a risk event during the study period. The odds ratio compares the odds of having the condition if the risk factor is present with the odds of having the condition if the risk factor is absent. Although many epidemiology research studies have provided odd ratios and have been available for more than thirty years, no analysis methodologies have utilized odd ratios to quantify ergonomic risks associated with the development of musculoskeletal disorders. Carpal tunnel syndrome, low back pain, and rotator cuff injuries occur in the general population at a given rate. These injuries are not unique to manufacturing or material handling job tasks. Additionally, there are nonoccupational risk factors with associated odd ratios that allow us to now determine the predominant cause of an injury. The odds ratio compares the odds of having the condition if the risk factor is present with the odds of having the condition if the risk factor is absent. Displaying results in terms of odd ratios allows the end user to understand the odds of a musculoskeletal injury in terms of the risk above the general population. Unlike many traditional ergonomic assessments that use fixed scales and arbitrary red, yellow, and green zones, odd ratios have no end limit. Therefore, as risk factors increase, increased risk is reflected as a higher odd ratio.
Mark Heidebrecht
Open Access
Article
Conference Proceedings
Effects of Glove Type and Gender on Lateral (Key) Pinch Strength Performance
Gloves are widely used in various industrial tasks, many of which involve fine motor functions such as finger/thumb pinching, gripping, and torque generation with wrist flexion. This study aimed to evaluate the effects of gender and glove type on key (lateral) pinch strength. Twenty healthy participants (10 males and 10 females) performed maximal lateral pinch efforts using a Baseline® mechanical pinch gauge. Each participant completed trials under five glove conditions: no gloves, latex, cotton, plastic, and chlorinated polyethylene (CPE). The study investigated how glove material and user gender influence hand performance in tasks requiring precision grip.
Wasim Alshammary
Open Access
Article
Conference Proceedings