A PRELIMINARY ASSESSMENT OF PHYSICAL WORK EXPOSURES AMONG ELECTRONIC WASTE WORKERS AT AGBOGBLOSHIE, ACCRA GHANA.

Occupational exposure associated with unstructured, informal e-waste recycling has received very limited attention. This study aimed to quantify the occupational physical exposures among informal e-waste workers at the largest e-waste site in Africa. A cross-sectional field survey of 163 male e-waste workers was conducted using a self-report occupational physical activity questionnaire, along with direct work observations, and pedometer estimates of walking activity for a subset of workers (n = 42). Results indicated significant differences in self-reported 7-day work exposures among the three main e-waste job categories, namely, collectors (n = 70), dismantlers (n = 73) and burners (n = 20). Prolonged walking, sitting and standing on five or more days in the workweek was frequently reported by collectors (87%), dismantlers (82%) and burners (60%), respectively. Nearly 90% of collectors and burners and 60% of dismantlers reported lifting and carrying on five or more days in the workweek. The exposure combinations identified suggest a risk for musculoskeletal disorders (MSDs). Findings call attention to the need for research examining potential associations between physical exposures and MSDs affecting e-waste workers in Agbogbloshie. The high exposure variability both between and within workers has implications for future exposure assessments conducted in unregulated, informal work settings.

Measuring Effects of Two-Handed Side and Anterior Load Carriage on Thoracic-Pelvic Coordination Using Wearable Gyroscopes.

Manual carrying of heavy weight poses a major risk for work-related low back injury. Body-worn inertial sensors present opportunities to study the effects of ambulatory work tasks such as load carriage in more realistic conditions. An immediate effect of load carriage is reflected in altered gait kinematics. To determine the effects of load carriage mode and magnitude on gait parameters using body-worn angular rate gyroscopes, two laboratory experiments (n = 9 and n = 10, respectively) were conducted. Participants performed walk trials at self-selected speeds while carrying hand loads in two modes (two-handed side vs. anterior) at four load levels (empty-handed, 4.5 kg, 9.1 kg, and 13.6 kg). Six measures of postural sway and three measures of thoracic-pelvic coordination were calculated from data recorded by four body-worn gyroscopes for 1517 gait cycles. Results demonstrated that, after adjusting for relative walking speed, thoracic-pelvic sway, and movement coordination particularly in the coronal and transverse planes, characterized by gyroscope-based kinematic gait parameters, are systematically altered by the mode of load carriage and load magnitude. Similar trends were obtained for an anthropometrically homogenous (Expt-1) and diverse (Expt-2) sample after adjusting for individual differences in relative walking speed. Measures of thoracic-pelvic coordination and sway showed trends of significant practical relevance and may provide sufficient information to typify alterations in gait across two-handed side vs. anterior load carriage of different load magnitudes. This study contributes to understanding the effects of manual load carriage on thoracic-pelvic movement and the potential application of body-worn gyroscopes to measuring these gait adaptations in naturalistic work settings.

Effect of Passenger Encumbrance and Mobility Aid Use on Dwell Time Variability in Low-floor Transit Vehicles.

Public transit serves users with a broad range of physical capabilities and design needs. However information about the operational effects of diverse users interacting with the transit system is scarce. This paper examined the occurrence and effects of boarding and alighting passengers with mobility aids (wheelchairs, scooters, walkers and canes), or with large items (carts, strollers, bicycles, or carrying an infant) on bus stop dwell time in a fixed-route bus service. On-board video data from low-floor public transit buses serving Ann Arbor, Michigan were used from 199 bus stops with at least one passenger boarding or alighting with a mobility aid or encumbered with a large item, and an additional 1642 bus stops without any mobility aids or encumbrances. A sequence of linear regression models examined the relationship between dwell time and the addition of variables representing passengers with mobility aids and encumbrances, and use of the on-vehicle access ramp, beyond explanatory variables typically used in dwell time analysis. Accounting for passengers boarding/alighting with mobility aids and encumbrances (p < 0.001) and use of the access ramp (p < 0.001) increased the variance explanation of a dwell time model based on boarding passengers by fare payment, alighting passengers by door use, and passenger load from 46% to 56%. Results indicate distinct patterns in the durations for boarding and alighting by passengers with vs. without mobility aids and encumbrances, and when a ramp is used by wheeled mobility users vs. ambulatory passengers with walking aids. The findings suggest that accounting for the presence of passengers with mobility aids or encumbrances and ramp use in dwell time analyses could help transit operators make their service operationally more efficient and inclusive for all passengers and encourage more use of fixed-route transit among individuals with disabilities.

A Narrative Review on Contemporary and Emerging Uses of Inertial Sensing in Occupational Ergonomics.

Accurate, reliable, and cost-effective quantification of real-time biomechanical exposures in occupational settings remains an enduring pursuit in ergonomics. Miniaturized, wireless, body-worn inertial sensors offer opportunities to directly measure vast and personalized kinematics data in both laboratory and applied settings. This review investigated the contemporary and emerging uses of wearable inertial sensing technology in occupational ergonomics research related to biomechanical exposure assessment in physical work. A review and narrative synthesis of 78 peer-reviewed studies was conducted. A conceptual framework was used for scoping and synthesizing the reviewed scientific literature. Review findings help to contextualize contributions of this emerging technology to the broader goals of reducing work-relevant musculoskeletal trauma disorders. The review made evident that despite the growing interest in wearable inertial sensing technologies for ergonomics research, its use in applied settings still lags. The review also identified differences in sensor attachment locations and methods and measures for calibration and validation, and inconsistent criteria for reporting and assessing biomechanical exposures even across studies with similar objectives. Emerging applications include combining inertial sensing with predictive modeling for obtaining cumulative exposure data, and providing real-time feedback about biomechanical work demands. The manuscript concludes with research directions for enabling inertial sensing technologies as a tool for online biomechanical exposure assessment and feedback, which has particular appeal in non-repetitive work settings.

Revisiting Clear Floor Area Requirements for Wheeled Mobility Device Users in Public Transportation.

Current accessibility standards in the U.S. prescribe minimum dimensions for 'clear floor area' to accommodate wheeled mobility device (WhMD) users on transportation vehicles. Prior research on the anthropometry of WhMD users (n = 500) indicates that these dimensions are too small to accommodate the size of many occupied wheeled mobility devices, especially power chairs and scooters. This paper describes a development project designed to update the evidence for these technical criteria and communicate them to the vehicle designers and accessibility standards developers in a manner that would facilitate making good decisions. An interactive web-based design tool was developed for determining the dimensions of clear floor area to achieve a user-specified level of physical accommodation based on occupied device length and width measurements taken on 500 WhMD users. The web-based design tool is now available to practitioners who seek to accommodate a wider range of WhMD users than the minimum standards required by regulations. The design tool is also intended as a visual evidence base for regulatory activity and universal design practice with higher ambitions. The advent of driverless automated vehicles will increase the importance of accessibility and usability to accommodate the diversity of riders with disabilities. Clear floor space to enable independent ingress, interior circulation and egress among WhMD users will be a foremost concern. The transportation industry, standards developers, disability advocates, mobility device manufacturers and prescribers need to understand the limitations of current accessibility standards and work to address these limitations through updated vehicle design standards and policies.

Obstacle clearance performance in individuals with high body mass index.

The objective of this study was to quantify performance in an obstacle clearance task among individuals with excess body weight or body mass index (BMI). Task performance was operationalized as the maximum obstacle height cleared, four duration measures of successful task completion and compensatory movements used in the process of task completion. Eighteen participants with a BMI exceeding 30 kg/m2 completed a laboratory experiment that required stepping over seven lightweight obstacles. Obstacle heights were sequentially increased from 36 cm in 5 cm increments until participants were unsuccessful or unable to clear the obstacle up to 66 cm. Successful task completions decreased from 100% at an obstacle height of 36 cm to 66.1% at 66 cm. Higher obstacle heights were associated with significantly fewer task completions, longer leading and trailing leg stance and overall task duration, and more frequent use of compensatory movements for successful obstacle clearance. Cox PH regression was used to test the association between probability of obstacle clearance and normalized obstacle height adjusting for BMI, standing balance, and type of compensatory movement used, namely, hover and pivot motions involving the leg, and hands for bracing. The probability of successful task completion significantly decreased with increases in BMI (hazard ratio, HR = 1.14, 95% CI: 1.05-1.25), and increased with use of a leg pivot motion (HR = 0.30, 95% CI: 0.09-0.96) during task completion, after adjusting for standing balance and other types of compensatory movements. Overall, the results demonstrated that obstacle clearance performance is affected by an individual's BMI and the use of compensatory behaviors for regaining stability. The ability to recruit internal and external stabilization techniques could potentially serve as a clinical indicator of reduced fall risk and be the focus of fall prevention interventions. Implications for evaluating stability, fall risk, and identifying modifiable factors for fall prevention in the obese population are discussed.

Integrating Interprofessional Collaborative Practice Into Occupational and Environmental Health and Safety Education: Results of a Feasibility Study.

OBJECTIVE: Although occupational health and safety programs are expected to prepare graduates to function in an interprofessional collaborative environment, research to support training in this area is far less common in this discipline than among clinical programs. We incorporated interprofessional education (IPE) competencies into an occupational health and safety course for graduate students in diverse disciplines (public health, engineering, nursing) and evaluated effectiveness. METHODS: We assessed course offerings for content learning and attitudes toward IPE and analyzed data using a mixed-methods approach. RESULTS: In general, students increased their understanding of the role of other disciplines, confidence in working in interprofessional teams, and valuation of IPE. CONCLUSION: Introducing IPE competencies into graduate education in worker health and safety is feasible and can equip students to more effectively work in occupational health-oriented multidisciplinary teams.

The Impact of COVID-19 and Pandemic Mitigation Measures on Persons With Sensory Impairment.

PURPOSE: To assess the impact of the COVID-19 pandemic and associated mitigation measures on persons with sensory impairments (SI), including visual impairments (VI) and hearing impairments (HI). DESIGN: Cross-sectional survey. METHODS: Adults with VI (best-corrected visual acuity <20/60 in the better-seeing eye), HI (International Classification of Diseases, Tenth Revision, codes), and age- and sex-matched controls (n = 375) were recruited from the University of Michigan. The 34-item Coronavirus Disability Survey was administered. Both χ2 tests and logistic regression were used to compare survey responses between groups. RESULTS: All groups reported high levels of disruption of daily life, with 80% reporting "a fair amount" or "a lot" of disruption (VI: 76%, HI: 83%, CT: 82%, P = .33). Participants with VI had greater difficulty with day-to-day activities and were more likely to cite the following reasons: caregiver was worried about COVID-19 (odds ratio [OR]VI = 7.2, 95% CI = 3.5-14.4, P < .001) and decreased availability of public transportation (ORVI = 5.0, 95% CI = 1.5-15.6, P = .006). Participants with VI, but not HI, showed a trend toward increased difficulty accessing medical care (ORVI = 2.0, 95% CI = 0.99-4.0, P = .052) and began relying more on others for day-to-day assistance (ORVI = 3.1, 95% CI = 1.6-5.7, P < .001). Overall, 30% reported difficulty obtaining trusted information about the pandemic. Those with VI reported more difficulty seeing or hearing trusted information (ORVI = 6.1, 95% CI = 1.6-22.1, P = .006). Employed participants with HI were more likely to report a reduction in wages (ORHI = 2.5, 95% CI = 1.2-5.3, P = .02). CONCLUSIONS: Individuals with VI have experienced increased disruption and challenges in daily activities related to the pandemic. People with SI may benefit from targeted policy approaches to the current pandemic and future stressors. Minimal differences in some survey measures may be due to the large impact of the pandemic on the population as a whole. The SARS-CoV-2 (COVID-19) pandemic and public health mitigation measures have had an exceedingly large impact around the globe. As of the time of writing, more than 114 million global cases (28 million US) had been diagnosed, and there had been more than 2.5 million fatalities attributed to COVID-19 (517,000 US).1,2.

Wheeled Mobility Use on Accessible Fixed-Route Transit: A Field Study in Environmental Docility.

Multiple field studies provide qualitative accounts of usability barriers experienced by users of wheeled mobility devices on public transit. This study aimed to examine these usability barriers from the theoretical perspective of Environmental Docility by quantifying the relationship between functional capabilities of wheeled mobility device users and ingress-egress performance on accessible fixed-route transit vehicles in an urban setting. Twenty-eight wheeled mobility users each completed three trips on a predetermined route through the local public transit system. Ingress and egress times, user-reported usability ratings and open-ended comments were analyzed. Regression analyses indicated significant interactions between age and minimum parallel-park length on ingress and egress times. Specifically, lower functional capability reflected in older age and less maneuvering ability predicted decreased performance (longer ingress-egress times), indicating less adaptability to environmental demands and agreement with the Environmental Docility Hypothesis. Usability ratings and comments revealed difficulty with negotiating access ramps and turning maneuvers in the vehicle interior and in proximity to other passengers. Despite compliance with accessibility standards, current design of transit vehicles present substantial usability barriers for wheeled mobility users. Environmental Docility provides a theoretical basis to identifying modifiable factors related to person and environment for improving usability of public transit for people aging and/or with mobility impairments.

Functional Data Representation of Inertial Sensor-based Torso-Thigh, Knee, and Ankle Movements during Lifting.

This study examined the goodness-of-fit of using a sigmoid function to characterize time-series angular displacement trajectories during two-handed anterior lifting. Twenty-six participants performed two-handed anterior lifting with a low (4.5 kg) vs. high (22.7 kg) load at floor vs. knee lifting height. A sigmoid function with three parameters was fit to the torso-thigh included angle, knee flexion-extension (F-E), and ankle F-E angles in the sagittal plane obtained from body-worn inertial sensors. Mean ± SD RMSE between measured vs. fitted trajectories were 3.6 ± 2.9°, 3.9 ± 4.2°, and 2.7 ± 2.8° for the torso-thigh included angle, knee F-E, and ankle F-E angles, respectively. Findings suggest that the sigmoid function adequately describes the trajectory shape of two-handed lifting kinematics. Functional representations facilitate data aggregation and feature extraction in large time-series datasets encountered in inertial-based motion analysis and machine learning applications.

Accessibility Retrofit of a Shared Automated Vehicle: Challenges and Lessons Learned.

Driverless shared automated vehicles (SAVs) have the potential to substantially improve independent mobility for the growing number of older adults and people with disabilities who are unable or ineligible to drive. However, early designs and deployments of SAVs have lacked accommodations for people with disabilities. This article describes a case study where post-production modifications were performed on a commercial electric SAV in an attempt to comply with US accessibility guidelines for conventional vehicles. Findings emphasize the key human factors considerations for physical accessibility and some lessons learned in order to inform the broader conversation about the accessible design of emerging SAVs. The case study highlights the need for considering accessibility and usability early in the design of complex technological systems such as automated vehicles.

INVESTIGATING INCLUSIVE DESIGN OF SHARED AUTOMATED VEHICLES WITH FULL-SCALE MODELING.

Shared automated vehicles (SAVs) in the form of low-speed driverless shuttles have the potential to improve independent mobility for older adults and people with disabilities. At full vehicle autonomy and in the absence of an onboard operator, tasks such as ingress-egress, interior circulation, and securement of passengers and carry-on items will need to be safe, efficient, and independent. This paper describes a novel laboratory apparatus for conducting inclusive design research related to SAVs and presents preliminary findings from an ongoing preliminary study examining the effects of interior design configuration on ingress-egress performance for six wheelchair users. Early findings emphasize the interactions between diverse user abilities and technology design on user performance. The study demonstrates the potential benefit of full-scale physical simulations to investigating a broad range of usability and inclusive design issues related to emerging SAVs.

Use of the International Classification of Functioning, Disability and Health to Measure Public Transportation Barriers among Older Adults.

The International Classification of Functioning, Disability, and Health (ICF) is a universal framework used to classify human functioning in clinical and rehabilitative domains. The objective of this study was to examine the utility of the ICF as a framework to categorize and measure barriers to public transportation reported by older adults. ICF coding techniques were applied to sixty paratransit applications for analyzing user-reported barriers to public transportation. Paratransit users were divided into groups based on age (young old vs. oldest old) and ambulatory level (non- vs. ambulatory). Analysis identified 119 instances of user-reported environmental barriers ranging from technology requirements to system/service-based factors, though the prevalence of different barriers differed across groups. Overall, the methodology appears promising. Understanding the complex relationships between functioning and different transportation barriers experienced by specific sub-populations could help identify unmet transportation needs, generate precise research questions, and support the development of inclusive transportation technologies and systems.

Wearable inertial sensors for human movement analysis: a five-year update.

INTRODUCTION: The aim of the present review is to track the evolution of wearable IMUs from their use in supervised laboratory- and ambulatory-based settings to their application for long-term monitoring of human movement in unsupervised naturalistic settings. AREAS COVERED: Four main emerging areas of application were identified and synthesized, namely, mobile health solutions (specifically, for the assessment of frailty, risk of falls, chronic neurological diseases, and for the monitoring and promotion of active living), occupational ergonomics, rehabilitation and telerehabilitation, and cognitive assessment. Findings from recent scientific literature in each of these areas was synthesized from an applied and/or clinical perspective with the purpose of providing clinical researchers and practitioners with practical guidance on contemporary uses of inertial sensors in applied clinical settings. EXPERT OPINION: IMU-based wearable devices have undergone a rapid transition from use in laboratory-based clinical practice to unsupervised, applied settings. Successful use of wearable inertial sensing for assessing mobility, motor performance and movement disorders in applied settings will rely also on machine learning algorithms for managing the vast amounts of data generated by these sensors for extracting information that is both clinically relevant and interpretable by practitioners.

Musculoskeletal Disorders in Unstructured, Unregulated Work: Assessment Methods and Injuries.

Unstructured and unregulated work is expanding fast among low- and middle-income countries (LMICs). Furthermore, accumulation of urban waste resulting from overconsumption is a global concern. Hence, waste management and recycling have received increased attention. One specific waste category pertaining to electrical and electronic waste (e-waste) is growing at a higher rate than other waste streams. Recycling of e-waste is largely informal and disproportionately relies on LMICs, exposing workers to various occupational and environmental health risks. In order to promote safer work practices and limit a broad range of occupational health and safety concerns associated with informal manual work, the broader psychosocial and sociocultural environment also deserves attention. This symposium will discuss contemporary issues in informal, unregulated, unstructured work in LMICs, primarily in Africa and South America. The goal of the symposium is to call attention to both, the unique occupational context of informal work, and the need for new ergonomics methods to address occupational exposure assessment and musculoskeletal injury prevention adapted to informal work in limited resource settings.

Occupational and Environmental Health Effects of Informal Electronic Waste Recycling - A Focus on Agbogbloshie, Ghana.

The unregulated and unorganized structure of informal electronic waste recycling worksites exposes workers to numerous occupational hazards. This context also presents research challenges in collecting exposure data to establish linkages with adverse health effects and development of risk-mitigating strategies. This paper presents some findings from a 5-year multinational and multi-institutional collaboration of academic and government partners, which documented extensive occupational and environmental health conditions at the Agbogbloshie electronic waste site in central Accra, Ghana.

Work-Related Exposures and Musculoskeletal Disorder Symptoms among Informal E-Waste Recyclers at Agbogbloshie, Ghana.

Recycling of electrical and electronic waste (e-waste) in developing countries is mostly conducted in the informal sector consisting of low skilled workers. Informal e-waste recycling predominantly involves the physically demanding work of manually collecting, dismantling and burning of e-waste items to extract reusable components and valuable metals including gold or copper. This cross-sectional study investigated the effects of manual e-waste recycling work on the musculoskeletal health of 176 workers at Agbogbloshie in Accra, Ghana - the largest informal e-waste dumpsites in Africa. Findings indicate significant associations between prolonged walking and weighted MSD symptom scores for the lower extremities, and between manual material handlings tasks and weighted MSD symptom scores for the upper extremities and lower back. The study calls attention to the need for ergonomics research in the informal work sector to promote safer practices and address a range of worker health concerns.

Comparison of ergonomic risk factors and work-related musculoskeletal disorders among dismantler and burners of electronic waste in Agbogbloshie, Accra Ghana.

Rudimentary methods for electronic waste (e-waste) recycling employed in developing countries are a source of work-related musculoskeletal disorders (WRMSDs). A summarized comparison of WRMSDs and preliminary exposure assessment among e-waste dismantlers (D) and burners (B) in Agbogbloshie, Ghana is presented. A cross-sectional study was conducted to investigate WRMSDs and associated risk factors using the Cornell Musculoskeletal Discomfort Questionnaire and a newly developed ergonomic assessment tool. Results indicated higher WRMSDs prevalence in the lower back (68% D vs. 52% B; p = 0.172), shoulder (41% D vs. 29% B; p = 0.279) and upper arm (33% D vs 5% B; p = 0.010). Moderate to severe trunk flexion, high force exertion, repetition and vibration were prevalent risk factors among workers and were significantly higher in dismantlers than burners (p ≤ 0.001). Detailed ergonomic studies investigating the relationship between physical exposures and WRMSDs are needed to provide a deeper understanding of WRMSD causation in e-waste workers and more particularly in unstructured, unregulated work.

Musculoskeletal Disorder Symptoms among Workers at an Informal Electronic-Waste Recycling Site in Agbogbloshie, Ghana.

Informal recycling of electrical and electronic waste (e-waste) has myriad environmental and occupational health consequences, though information about the chronic musculoskeletal health effects on workers is limited. The aim of this study was to examine the prevalence and intensity of self-reported musculoskeletal disorder (MSD) symptoms among e-waste workers at Agbogbloshie in Ghana-the largest informal e-waste dumpsite in West Africa-relative to workers not engaged in e-waste recycling. A standardized musculoskeletal discomfort questionnaire was administered to 176 e-waste workers (73 collectors, 82 dismantlers, and 21 burners) and 41 workers in a reference group. The number of body parts with musculoskeletal discomfort were 1.62 and 1.39 times higher for collectors and dismantlers than burners, respectively. A 1-week discomfort prevalence was highest for collectors (91.8%) followed by dismantlers (89%), burners (81%), and the reference group (70.7%). The discomfort prevalence for e-waste workers was highest in the lower back (65.9%), shoulders (37.5%), and knees (37.5%). Whole-body pain scores (mean ± SE) were higher for collectors (83.7 ± 10.6) than dismantlers (45.5 ± 7.6), burners (34.0 ± 9.1), and the reference group (26.4 ± 5.9). Differences in prevalence, location, and intensity of MSD symptoms by the e-waste job category suggest specific work-related morbidity. Symptom prevalence and intensity call attention to the high risk for MSDs and work disability among informal e-waste workers, particularly collectors and dismantlers.

Anthropometry and standards for wheeled mobility: an international comparison.

Space requirements for accommodating wheeled mobility devices and their users in the built environment are key components of standards for accessible design. These requirements typically include dimensions for clear floor areas, maneuvering clearances, seat and knee clearance heights, as well as some reference dimensions on wheeled mobility device sizes. Recent research from four countries was reviewed and compared with their prevailing accessibility standards to identify needs for improving standards. Findings from ongoing anthropometry research on wheeled mobility in the U.S. were used for evaluating the adequacy of existing U.S. accessibility standards. Preliminary analysis suggests that the U.S. standards, which are based on research conducted in the 1970s, need to be updated to address advances in wheeled mobility technology and changes in user demographics. The analysis highlights the importance of integrating research with standards development, organizing international collaborations, and developing international standards.