Comparative study of upper limb load assessment and occurrence of musculoskeletal disorders at repetitive task workstations

The Sensor-Based Biomechanical Risk Assessment at the Base of the Need for Revising of Standards for Human Ergonomics

Due to the epochal changes introduced by "Industry 4.0", it is getting harder to apply the varying approaches for biomechanical risk assessment of manual handling tasks used to prevent work-related musculoskeletal disorders (WMDs) considered within the International Standards for ergonomics. In fact, the innovative human-robot collaboration (HRC) systems are widening the number of work motor tasks that cannot be assessed. On the other hand, new sensor-based tools for biomechanical risk assessment could be used for both quantitative "direct instrumental evaluations" and "rating of standard methods", allowing certain improvements over traditional methods. In this light, this Letter aims at detecting the need for revising the standards for human ergonomics and biomechanical risk assessment by analyzing the WMDs prevalence and incidence; additionally, the strengths and weaknesses of traditional methods listed within the International Standards for manual handling activities and the next challenges needed for their revision are considered. As a representative example, the discussion is referred to the lifting of heavy loads where the revision should include the use of sensor-based tools for biomechanical risk assessment during lifting performed with the use of exoskeletons, by more than one person (team lifting) and when the traditional methods cannot be applied. The wearability of sensing and feedback sensors in addition to human augmentation technologies allows for increasing workers' awareness about possible risks and enhance the effectiveness and safety during the execution of in many manual handling activities.

Work-related upper limb disorders and risk assessment among automobile manufacturing workers: A retrospective cohort analysis

OBJECTIVE

To estimate the three-year cumulative risk of work-related upper limb disorders (WRULDs) in a cohort of automotive industry workers and to provide a first test of the ability of the European Assembly Worksheet (EAWS) methodology to predict WRULDs.

METHODS

292 workers were investigated by reviewing workers' medical records during the period from 2012-2015 to determine their exposure to biomechanical overload according to EAWS risk scores (0-25, low risk, Green zone; 26-50, medium risk, Yellow zone; >50, High risk; Red zone).

RESULTS

The risks were 0.83%, 5.71%, and 11.88% for the Control (unexposed), Green and Yellow Groups, respectively. Only the comparison between the Yellow/Control Groups was significant (p = 0.0014). In total, we observed 17 cases of musculoskeletal disorders (MSDs) (14 symptomatic and 3 cases detected by physical examination).

CONCLUSIONS

The EAWS is a useful tool for the preliminary risk assessments of biomechanical overload among automotive industry workers. The finding of mainly non-specific disorders highly suggests that health surveillance should aim to identify not only full-blown diseases but also symptomatic cases.

The Status of Musculoskeletal Disorders and Its Influence on the Working Ability of Oil Workers in Xinjiang, China

The purpose of this study was to investigate the status of musculoskeletal disorders (MSDs) and its influence on the working ability of oil workers, and to provide a theoretical basis for helping lessen the burden of MSDs and improve the man-machine environment of oil workers. The cluster sampling method was used to study 2000 workers who had been employed for more than 1 year in this field. We investigated the prevalence rate and the work ability index (WAI). A total of 1935 valid questionnaires were collected, a response rate of 96.75%. There were 1639 people who had suffered from MSDs in the past year, a prevalence rate of 84.7%. The damage detection rate in female oil workers was higher than in males, and the damage detection rate in workers aged 30 to 45 years was higher than that in the other two age groups. The detection rate in less highly-educated oil workers was higher than that in more highly-educated workers. The detection rate in divorced workers was higher than that in other groups. The detection rate in workers between the number of working years of 18 to 25 years was higher than in the other two groups. The detection rate in workers with a high professional title was significantly higher than that in lower-titled workers (p < 0.05). The results showed that the WAI scores of the subjects with MSDs were significantly lower than for subjects without MSDs (p < 0.05). In a logistic regression analysis, sex, number of working years and WAI index all had an impact on MSDs. We concluded that due to the demands of their role, the oil workers had serious MSDs that influenced their working ability.