Objective: To measure and determine the occupational cardiovascular workload and cardiovascular fitness among older employees (50 +) in four physically demanding occupational groups. Methods: Health investigations, including aerobic capacity, were performed on 120 construction and kitchen workers, cleaners, and assistant nurses. Cardiovascular load was assessed over three working days using heart rate (HR) measurements. Data was processed for average loads (HR and Relative HR reserve (%HRR)) and measures describing variations in loads, such as time spent in different heart rate intensities. Results: Participants’ mean age was 57 (SD 4.1) years, and 63% of the participants were female. The mean %HRR over occupational groups was 24.9% (SD 6.8). Of the participants, 43% had an average cardiovascular load above 24.5%HRR and 11% over 33%HRR. Depending on the work sector, 22–37% of the worktime was spent in intensities over 30%HRR, and 2–4% was spent in cardiovascular intensities over 50%HRR. The average VO<inf>2</inf>max was 33.2 (SD 8.2) ml/kg/min for all, for men 39.0 (SD 7.0), and for women 29.8 (SD 6.9). Conclusion: We found a high mean cardiovascular load at work among the senior workers in all four work sectors, but low proportions of the worktime were spent in high intensity levels. Despite a high mean cardiovascular load at work, a high proportion of the workers had low cardiovascular fitness. Given the possible negative effects of occupational physical activity and to meet future demographic challenges, future interventions should aim to reduce physical loads and increase physical fitness in the workforce.

Previous study showed that surgical prismatic loupes improved surgeon physical workload and neck discomfort in a lab setting. However, there is limited knowledge regarding the effects of prismatic loupes in operating room. Fifteen surgeons performed two similar operations (median duration of 54 minutes) using prismatic and conventional loupes. The muscle activities and work postures were recorded. Questionnaires including body part discomfort and usability were completed. Compared to conventional loupes, prismatic loupes led to a significant decrease in muscle activity levels in the upper trapezius and neck extensors, head forward bending, and neck pain postoperatively (all p < 0.05). Most surgeons reported high usability scores for the prismatic loupes. The study showed that surgical prismatic loupes can improve surgeons’ intraoperative physical workload and musculoskeletal discomfort in real surgeries in short term. Future studies are needed to investigate the long-term effects of using prismatic loupes on surgeon well-being and surgical performance.

To better connect the needs of industrial stakeholders and technology development in smart wearables for ergonomics, the DiPMaS project uses a co-design methodology to develop a digital platform to support manufacturing staff to improve health, safety and quality. This conference contribution aims to provide an overview of the results of the project so far, and present the results from the user survey on the prioritized functionalities of the digital platform. The findings can contribute to the development of future digital platforms for ergonomics applications and facilitate the implementation of such platforms within the industry.

Smart workwear systems with embedded inertial measurement unit sensors are developed for convenient ergonomic risk assessment of occupational activities. However, its measurement accuracy can be affected by potential cloth artifacts, which have not been previously assessed. Therefore, it is crucial to evaluate the accuracy of sensors placed in the workwear systems for research and practice purposes. This study aimed to compare in-cloth and on-skin sensors for assessing upper arms and trunk postures and movements, with the on-skin sensors as the reference. Five simulated work tasks were performed by twelve subjects (seven women and five men). Results showed that the mean (+/- SD) absolute cloth-skin sensor differences of the median dominant arm elevation angle ranged between 1.2 degrees (+/- 1.4) and 4.1 degrees (+/- 3.5). For the median trunk flexion angle, the mean absolute cloth-skin sensor differences ranged between 2.7 degrees (+/- 1.7) and 3.7 degrees (+/- 3.9). Larger errors were observed for the 90th and 95th percentiles of inclination angles and inclination velocities. The performance depended on the tasks and was affected by individual factors, such as the fit of the clothes. Potential error compensation algorithms need to be investigated in future work. In conclusion, in-cloth sensors showed acceptable accuracy for measuring upper arm and trunk postures and movements on a group level. Considering the balance of accuracy, comfort, and usability, such a system can potentially be a practical tool for ergonomic assessment for researchers and practitioners.

Encouraging feedback is shown to increase motivation and facilitate learning in different settings, though there is a lack of knowledge of applying it in work technique training. This pilot study aimed to evaluate two accumulated vibrotactile feedback strategies for work technique training using a smart workwear system. Eight women and two men participated in the study. They were divided into two groups, receiving the corrective feedback or the combined corrective and encouraging feedback while doing simulated manual handling tasks in a lab environment. Questionnaires and semi-structured interviews were used to evaluate the motivation, learning, and user experiences. In this small sample size, we saw that both groups significantly improved their work technique of upper arm and trunk postures, and no significant difference between groups was seen. In addition, both groups reported increased ergonomic awareness, were satisfied with the feedback training, and considered the system useful. However, the combined feedback group had slightly lower ratings of motivation and more negative experiences of the corrective feedback itself compared to the corrective feedback group. Both groups had positive experiences with the encouraging feedback. Future research should consider investigating the long-term learning effects of using solely corrective or encouraging accumulated feedback for work technique training with such systems.

BackgroundMusculoskeletal disorders (MSDs) are critical occupational and social problems. With the improvement of production mechanization and automation, and the widespread application of computers, more occupations are exposed to static postures and load. This study explored the role of inflammation in the association between static postures exposure and MSDs. MethodsThis study adopted a prospective nested case-control design in which 66 lower back MSDs cases and 66 healthy controls were selected from a cohort study of university employees. The personal information, postural load, musculoskeletal symptoms, pressure pain thresholds (PPTs), and inflammatory cytokines were collected. Logistic and linear regressions were used to investigate the association among postural load, inflammatory cytokines, and lower back MSDs. Mediation analysis was used to calculate the mediation effect. ResultsThe results of logistic and linear regressions showed that postural load and inflammatory cytokines were positively associated with lower back MSDs (P < 0.05), and postural load was positively associated with inflammatory cytokines (P < 0.05). Further, mediation analysis showed that the mediation effect of postural load on the lower back MSDs through TNF-alpha was 0.073 (95%CI: 0.025-0.128), and the mediation effect of posture load on the lower back MSDs through IL-6 was 0.098 (95%CI: 0.041-0.179), respectively. ConclusionStatic postures were associated with the occurrence of MSDs through inflammatory cytokines, and low-level inflammation may be a critical early event in the generation of MSDs. This study may help bridge the gap of potential mechanisms linking static postures to increased risks of MSDs, and provide new evidence for targeted protection against the global increasing MSDs.

Introduction: Multi-site musculoskeletal symptoms (MSS) are considered to be more common and have more serious consequences than single-site MSS. This study aimed to determine whether derived patterns of MSS may be identified in electronic assembly workers and if extracted MSS classes are associated with personal and work-related factors. Method: A cross-sectional questionnaire study was performed with 700 participating electronic assembly workers. The questionnaire included individual factors, psychosocial and physical exposures, and MSS. The derived patterns of MSS and their relationships with ergonomic factors were analyzed using latent class analysis (LCA) and multinomial logistic regression models (MLRM). Results: The 1-year prevalence of MSS affecting only one body site or two or more body sites was 14.9% and 32.7%, respectively. The results of LCA showed three distinct classes of MSS patterns, which were labelled 'MSS in most sites' (5.0%), 'MSS in neck and shoulder' (27.0%), and 'MSS in one or no site' (68.0%). The results of MLRM showed that the 'MSS in neck and shoulder' was associated with job tenure (OR 5.579, 95% CI 2.488-12.511), excessive dynamic and static loads (OR 3.868, 95% CI 1.702- 8.793 and OR 5.270, 95% CI 2.020-13.747, respectively); while the 'MSS in most sites' was associated with high job demands (OR 4.528, 95% CI 1.647-12.445) and excessive dynamic loads (OR 111.554, 95% CI 4.996-2490.793). Conclusions: The results showed unique patterns of MSS among electronic assembly workers that were associated with personal and work-related factors. Practical applications: The findings highlight that the high prevalence of multi-site MSS in this group should be a focus. It also provides further evidence that LCA considering the number and location of anatomical sites involving MSS can be used to determine distinct classes of MSS patterns, which is of great significance for the epidemiological study and management of MSS in the future.

Objective Forward bending of the back is common in many jobs and a risk factor for sickness absence. However, this knowledge is based on self-reported forward bending that is generally imprecise. Thus, we aimed to investigate the dose-response relation between device-measured forward bending at work and prospective register-based risk of long-term sickness absence (LTSA). Methods At baseline, 944 workers (93% from blue-collar jobs) wore accelerometers on their upper back and thigh over 1-6 workdays to measure worktime with forward bending (>30 degrees and >60 degrees) and body positions. The first event of LTSA (>= 6 consecutive weeks) over a 4-year follow-up were retrieved from a national register. Compositional Cox proportional hazard analyses were used to model the association between worktime with forward bending of the back in an upright body position and LTSA adjusted for age, sex, body mass index (BMI), occupational lifting/carrying, type of work, and, in an additional step, for leisure time physical activity (PA) on workdays. Results During a mean worktime of 457 minutes/day, the workers on average spent 40 and 10 minutes on forward bending >30 degrees and >60 degrees in the upright position, respectively. Five more minutes forward bending >30 degrees and >60 degrees at work were associated with a 4% [95% confidence interval (CI) 1.01-1.07] and 8% (95% CI 1.01-1.16) higher LTSA risk, respectively. Adjustment for leisure-time PA did not influence the results. Conclusion We found a dose-response association between device-measured forward bending of the back and prospective LTSA risk. This knowledge can be integrated into available feasible methods to measure forward bending of the back for improved workplace risk assessment and prevention.

Wrist velocity is an important risk factor for work-related musculoskeletal disorders in the elbow/hand, which is also difficult to assess by observation or self-reports. This study aimed to evaluate a new convenient and low-cost inertial measurement unit (IMU)-based method using gyroscope signals against an electrogoniometer for measuring wrist flexion velocity. Twelve participants performed standard wrist movements and simulated work tasks while equipped with both systems. Two computational algorithms for the IMU-based system, i.e., IMUnorm and IMUflex, were used. For wrist flexion/extension, the mean absolute errors (MAEs) of median wrist flexion velocity compared to the goniometer were <10.1 degrees/s for IMUnorm and <4.1 degrees/s for IMUflex. During wrist deviation and pronation/supination, all methods showed errors, where the IMUnorm method had the largest overestimations. For simulated work tasks, the IMUflex method had small bias and better accuracy than the IMUnorm method compared to the goniometer, with the MAEs of median wrist flexion velocity <5.8 degrees/s. The results suggest that the IMU-based method can be considered as a convenient method to assess wrist motion for occupational studies or ergonomic evaluations for the design of workstations and tools by both researchers and practitioners, and the IMUflex method is preferred. Future studies need to examine algorithms to further improve the accuracy of the IMU-based method in tasks of larger variations, as well as easy calibration procedures.

Objective To survey the prevalence of lower extremity musculoskeletal disorders (MSDs) among Chinese manufacturing workers, and to identify the associated factors. Design Observational study with cross-sectional design. Setting A self-administered questionnaire survey was conducted in four manufacturing factories in China. Participants 7908 manufacturing workers were included in this study after excluding non-conforming personnel. Outcome measures Individual and work-related information, and MSDs in the whole leg and knee region were measured by the anonymous self-administered questionnaire. Individual and work-related factors associated with MSDs and their effects were identified through multivariate logistic regression. Results Of all respondents, 3241 (41.0%) reported having had lower extremity MSDs in the recent 12 months, and for the knees, ankles/feet and hips/thighs were 29.5%, 23.9% and 16.7%, respectively. After confounder-adjusted single-factor analysis, 22 variables (of 24) were significantly related to the disorders. Factors like always kneeling/squatting for long periods, always standing for long periods and often lifting in an uncomfortable position were shown to have higher risks, with ORs of 2.77 (95% CI: 2.33 to 3.30), 2.30 (1.96 to 2.69) and 2.25 (2.04 to 2.47). Comparable results were found on knee disorders. The final model included 15 variables of demography, biomechanics and work organisation. The following factors showed increased risks of lower extremity MSDs: being female, being older, longer working years, higher body mass index (BMI), keeping the same posture for a long time, awkward position, shift work and monotonous work. Whereas having enough breaks reduced the risk. Conclusion The prevalence of lower extremity MSDs among Chinese manufacturing workers is high. The most commonly affected body regions were the knees and ankles/feet. Multiple factors were found associated with lower extremity MSDs including age, BMI, work experience, work organisations, physical ergonomics exposures, etc.