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Automotive assembly operations require power tools to secure fasteners and these operations have been linked to increased risk of musculoskeletal disorders. This work was designed to develop physical capability limits for direct current right-angle power tool (RAPT) operations using psychophysics. Forty females fastened joints of different hardness's using three fastening strategies, at three fastening frequencies. Participants chose to fasten, independent of orientation, joints up to 89 (10.6) Nm using Atlas Copco's TurboTight®, compared to 51.8 (8.1) Nm using Atlas Copco's Quickstep and 48.6 (10.2) Nm using Stanley's Automatic Tightening Control. The differences between fastening strategies were not as large when fastening soft joints; 59.2 (16.2), 52.3 (14.6), and 53.5 (11.3) Nm, respectively. As fastening frequency increased, participants chose lower target torque magnitudes to fasten. Based on this work, RAPT manufactures can adjust fastening strategies to improve their tool's ergonomics performance. Practitioner summary: Fastening tasks was identified as posing an injury risk to workers performing automotive assembly, yet presently there are no published physical capability limits for direct current right-angle power tool operation. Using a psychophysical methodology, physical capability limits for RAPT fastenings were established for different joint hardness, fastening frequencies and RAPT position/orientation. [ABSTRACT FROM AUTHOR]

Musculoskeletal disorders (MSDs) are prevalent under poor working situations. Where it is not possible to remove the root cause of MSDs, passive exoskeletons could be a solution. In this randomised cross-over field study we investigated the effect of a passive arm-support exoskeleton. Ten participants, recruited from a Dutch gas company, were measured with and without exoskeleton assessing muscle activity, heart rate (HR), arm elevation, and reported about their experiences. Participants spent more time in high arm elevation levels with the exoskeleton than without. Muscle activity was lower in the trapezius (Beta: -1.8 [-3.1; -0.4]) and deltoid (Beta: -1.4 [-2.3; -0.6]) muscles, but not the biceps muscle, during the measurements with exoskeleton than without, suggesting effectiveness of the exoskeleton. HR and discomfort did not statistically significantly differ between the two conditions. Participants would recommend an exoskeleton to their colleagues, but mainly for repetitive work. Their opinions about the usefulness during work varied.

Currently, there is no guidance on the training programme approach that should be provided to new sit-stand workstation users to optimally integrate workstation usage patterns into their working day. The objective of this research study was to determine if a training programme could influence long-term usage of sit-stand workstations. Thirty-five employees from the University of Waterloo volunteered to participate in this longitudinal study. Two different types of training programmes were delivered: (1) an example from industry and (2) based on current literature. There was an influence of training programme on the frequency of sit to stand transitions made each day. Those who received the additional training programme also reported sitting less, standing more and used their sit-stand workstations more consistently day-to-day than those who did not. Practitioner Summary: A longitudinal study was conducted to assess the impact of training programmes on sit-stand workstation usage. A training programme based on current literature resulted in more consistent sit-stand usage than an industry example. [ABSTRACT FROM AUTHOR]

Servicing and maintaining wind turbines may expose wind turbine technicians (wind techs) to musculoskeletal disorder (MSD) hazards. We aimed to characterise MSD hazard exposures and identify work elements that should be prioritised for MSD prevention efforts. A cross-sectional online survey methodology gathered data from 144 wind techs based on a convenience, non-probability sampling approach. The survey was developed using resources from the Ontario MSD Prevention Guideline, where cognitive interviewing yielded wind tech specific modifications. Climbing was the most physically demanding task, followed by torqueing/tensioning and manual materials handling (MMH). However, working in awkward and constrained postures emerged as the task most likely to cause or aggravate discomfort. Injecting ergonomic and human factors principles into wind turbine design should be a high priority. Re-engineering tools like torque tensioning devices may reduce MSD hazard exposures associated with tasks including torqueing/tensioning and MMH. We know little about musculoskeletal disorder (MSD) hazards associated with green jobs. By surveying wind turbine technicians, we learned that MSD hazards exists, and can be addressed by better considering human factors/ergonomics principles in the design of wind turbines and the tools required for service and maintenance operations. Abbreviations: MSD: musculoskeletal disorder; MMH: manual materials handling; Wind techs: wind turbine technicians; CRE-MSD: centre of research expertise for the prevention of musculoskeletal disorders; CanWEA: Canadiarn wind energy association; HFE: human factors/ergonomics; ASME: American Society of Mechanical Engineers; CSA: Canadian Standards Association [ABSTRACT FROM AUTHOR]

The distribution of exposure to biomechanical and organisational job stressors (BOJS) and associations with employment withdrawal (antenatal leave, unemployment) was examined in a case-control study of 1114 pregnant workers in California. We performed descriptive and multivariate logistic and multinomial regression analyses. At pregnancy onset, 57% were exposed to one or more biomechanical stressors, including frequent bending, heavy lifting and prolonged standing. One-third were simultaneously exposed to BOJS. Exposure to biomechanical stressors declined as pregnancy progressed and cessation often (41%) coincided with employment withdrawal (antenatal leave and unemployment). In multivariate modelling, whether we adjusted for or considered organisational stressors as coincident exposures, results showed that pregnant workers exposed to biomechanical stressors had increased employment withdrawal compared to the unexposed. Work schedule accommodations moderate this association. Paid antenatal leave, available to few US women, was an important strategy for mitigating exposure to BOJS. Implications for science and policy are discussed. Practitioner Summary:This case-control study showed that exposure to biomechanical stressors decline throughout pregnancy. Antenatal leave was an important strategy used for mitigating exposure among sampled California women with access to paid benefits. Employment withdrawal among workers exposed to BJOS may be reduced by proactive administrative and engineering efforts applied early in pregnancy. [ABSTRACT FROM AUTHOR]

The size and shape of users are an important consideration for many products and environments. Designers and engineers in many disciplines must often accommodate these attributes to meet objectives such as fit and safety. When practitioners have academic training in addressing these issues, it is typically through courses in Human Factors/Ergonomics (HF/E). This paper investigates education related to physical accommodation and offers suggestions for improvement. A survey was conducted wherein 21 instructors at 18 universities in the United States provided syllabi for 29 courses, which were analysed to determine topics related to anthropometry and resources used for the courses. The results show that within the US, anthropometry is covered in the majority of courses discussing physical ergonomics, but important related concepts were often omitted (e.g. digital human modelling, multivariate accommodation and variability across global populations). Curricula could be improved by incorporating more accurate anthropometry, multivariate problems and interactive online tools. Practitioner Summary: This paper describes a study investigating collegiate ergonomics courses within the US in the area of physical accommodation. Course schedules and texts were studied for their treatment of several topics related to accommodating the spatial requirements (anthropometry) of users. Recommendations are made for improving course curricula. [ABSTRACT FROM AUTHOR]

The primary objectives of the study were to 1) describe the physical exposures in a sawmill job with a high incidence of upper extremity musculoskeletal injuries in terms of multiple measures of posture, exertion and frequency (with varying definitions) and 2) to examine the comparability of those definitions. Surface electromyography and electrogoniometry were used to quantify the muscle demands and joint motions. Fourteen board edger operators from two sawmill facilities participated. All exposure assessments, with the exception of surface EMG measurements, were performed on the production lines. EMG measurements were performed within the facility in a location removed from the production line. The measurements showed that, on average, ranges of motions of 59, 102 and 84 degrees respectively in the planes of wrist radial/ulnar deviation, flexion/extension and pronation/supination were required to perform the job. Significant differences (p < .001) were observed between ranges of motion defined by peak postures and those due to peak postures required to perform the primary task only. Performance of the primary task required an average of 32% of maximum voluntary contraction from the forearm muscles assessed. Repetitions per day ranged, on average, from 2,015 to 9,365. Incidence of reported upper extremity musculoskeletal injuries in the two facilities assessed was found to be higher with the greater total exposure. However, examination of the trend with a standardized measure of injury incidence was not possible. [ABSTRACT FROM AUTHOR]