Prevalence and predictors of work-related musculoskeletal disorders among workers of a gold mine in south Kivu, Democratic Republic of Congo

The burden and risk factors of chronic musculoskeletal disorders among artisanal and small-scale miners in rural Rwanda

Objectives. In sub-Saharan Africa, mining employment continues to expose workers to a dangerous physical and psychosocial occupational environment. This study explored the prevalence of chronic musculoskeletal disorders (MSDs) and their risk factors among artisanal and small-scale miners. Methods. A cross-sectional study was conducted in eastern Rwanda in November 2022. Self-reported MSDs were assessed using the modified Nordic musculoskeletal questionnaire. The study used χ2 or t tests and multivariate analysis with backward stepwise selection for logistic regression to determine independent risk factors for chronic MSDs (lasting >3 months). Results. The prevalence of self-reported MSDs in the past week and chronic MSDs were 78.83% (n = 808 out of 1025) and 64.10% (n = 657), respectively. Higher odds of chronic MSD was significantly associated with employment length longer than 5 years, working in a high or very high intensity vibration and rock-drilling tasks. Rock-blasting tasks were associated with 38% lower odds for chronic MSDs. Discussion. Nearly 8 out of 10 artisanal and small-scale miners experienced MSDs. High-risk occupational characteristics increased the odds of chronic MSDs. Adoption of proper health and safety management systems, high standard mechanization, ergonomic training and better health-seeking behaviors may mitigate risks for MSDs in Rwanda and sub-Saharan Africa.

Prevalence and determinants of Musculoskeletal Disorders among quarry workers in The Gambia: a cross-sectional study

BACKGROUND

Musculoskeletal disorders (MSDs) are common work-related conditions that affect the musculoskeletal system owing to poor ergonomic practices, overexertion, and repetitive motions. Globally, MSDs account for a significant proportion of disabilities due to the physical tasks and demanding nature of jobs. Despite global efforts to reduce occupational hazards, little information is available on MSDs among quarry workers in Gambia. Therefore, this study aimed to explore the prevalence of MSDs and their associated factors in quarry workers in Gambia.

METHODS

This study adopted an analytical cross-sectional design that was conducted in 2023. A total of 258 quarry workers were selected from 4 quarries in the West Coast Region. Participants were randomly selected and the Standardised Nordic Questionnaire (SNQ) was modified and used with additional structured questionnaires. Data were collected using the Kobo Collect App and analyzed using IBM SPSS version 27.0. Bivariate analysis was conducted using binary logistic regression, Pearson's chi-square test, point-biserial correlation, and Fisher's exact test to identify the association between predictors and outcome variables. Statistical significance was considered at a p-value < 0.05, and the significance was also reported using an adjusted odds ratio (aOR) with a 95% Confidence Interval (CI).

RESULTS

The study revealed a high MSD prevalence of 93% among quarry workers, with the most affected body parts being the lower back (90.3%), shoulders (68.1%), and upper back (61.3%). Significant associations were observed between MSDs and factors such as nationality (p = 0.048), job description (p = 0.047), BMI score (p < 0.001), periodic health examination (p = 0.031), years of experience (p = 0.029), health and safety training (p = 0.044), and lifting or carrying weights (p = 0.044). Quarry workers whose nationality was Gambian had 82.8% (aOR = 0.172; 95% CI = 0.048-0.619) reduced odds of sustaining MSDs when compared to respondents whose nationality was non-Gambian. Increasing years of experience had 15.0% (aOR = 0.850; 95% CI = 0.725-0.997), increase in hours of daily work had 40.3% (aOR = 0.597; 95% CI = 0.386-0.925), and increasing BMI score had 29.9% (aOR = 0.701; 95% CI = 0.584-0.841) reduction in the odds of sustaining MSDs. However, increasing household size among quarry workers had 1.26 (aOR = 1.261; 95% CI = 1.015-1.566) higher odds of sustaining MSDs.

CONCLUSION

This study underscores a critical public health concern with the high prevalence of MSDs among quarry workers in The Gambia, which is associated with poor ergonomic training and inadequate safety training. Reducing the burden of MSDs in this population requires interventions that focus on better working conditions, ergonomic training, and regular health evaluations.

Assessing low-back loading during lifting using personalized electromyography-driven trunk models and NIOSH-based risk levels

Workplace injury risk due to physically demanding tasks (e.g., repeated lifting) is currently assessed using ergonomic guidelines. The Revised NIOSH Lifting Equation (RNLE) is a commonly used approach that assesses risk of low-back loading during different lifting tasks. Advances in musculoskeletal models have enabled the estimation of physiologically valid person-specific musculoskeletal models (pEMS) driven by surface electromyography and joint angle information. These models offer realistic estimates of objective parameters such as moments and compressive and shear loads at the lumbosacral joint. In this study, we applied both techniques (RNLE and pEMS) to assess risk and low-back loading in seven healthy participants performing lifting tasks at different risk levels. We found that the pEMS estimated objective parameters of low-back loading in line with the different risk levels proposed by RNLE. However, the low-back compressive and shear loads were higher than the limits proposed by the RNLE. Moreover, we show that the lumbosacral compressive loads can be a better parameter to demarcate risk levels. We recommend performing this assessment on a larger and diverse population for evaluation of personalized risk levels across lifting tasks in the industry. These approaches can be implemented with wearable sensorized garments to monitor personalized musculoskeletal health unobtrusively in the workplace providing us a better insight into possibility of individual risk.

Risk factors of musculoskeletal symptoms among industrial workers in Peninsular Malaysia

Objectives. The prevalence rate of work-related musculoskeletal disorders (WMSDs) globally is notably high. There are a limited number of studies investigating WMSDs and their associated risk factors. However, there are currently no data available for WMSDs among industrial workers in Peninsular Malaysia. This study aimed to identify the prevalence of WMSDs and associated risk factors among industrial workers experiencing WMSDs through their daily working tasks. Methods. A quantitative study using a questionnaire was conducted among industrial workers from rehabilitation centres and factories in Peninsular Malaysia. The analysis of 232 participant narratives aimed to identify the correlation between job tasks and musculoskeletal pain, especially in case of repetitive and heavy handling tasks. Results. The prevalence of WMSDs among industrial workers stands at 93.1%. The results also indicate that the most affected part of the body was the lower back, with 62.1% for 7 days or more in the last year, caused by industrial workers' job tasks. The prominent risk factors associated with body parts include gender, age, working hours and most difficult tasks with MSDs, especially in the lower back. Conclusion. This survey helps us to understand whether the workers are experiencing any discomfort, pain or disability related to workplace activities.

Space-time analysis of work-related musculoskeletal disorders in Brazil: an ecological study

This study aimed to analyze the incidence of work-related musculoskeletal disorders (WMSD) in Brazil from 2007 to 2019, examining the spatial, temporal, and spatiotemporal patterns of their occurrence. An ecological time series study was conducted using spatial analysis techniques. WMSD morbidity data from 2007 to 2019 were collected from the Brazilian Information System for Notificable Diseases of the Brazilian Health Informatics Department. Incidence rates were standardized and smoothed using the local empirical Bayes' theorem. Time trends were analyzed by segmented linear regression. Spatial analysis was performed using Moran's univariate global (I) and local (LISA) indexes. The spatiotemporal scan statistic was used to identify high-risk spatiotemporal clusters for WMSD. A total of 93,387 cases of WMSD were recorded in Brazil. Temporal trends showed an increase in all regions except the Northeast, which remained stable. The incidence of WMSD showed a spatial dependence, with spatial and space-time clusters identified, especially in the Southeast region, overlapping the largest economic-industrial center of the country. The spatiotemporal clustering observed in one region suggests the highest level of industrial and economic development. Our findings highlight the need to implement intersectoral surveillance policies, inspect working conditions, and invest in the prevention and promotion of workers' health.

Work-related musculoskeletal disorders among desludging operators in Uganda

BACKGROUND

Despite the limited evidence, desludging operators remain at a heightened risk of work-related musculoskeletal disorders (WMSDs). This study established the prevalence and predictors of WMSDs among desludging operators in Uganda.

METHODS

A digitalized structured questionnaire was used to collect cross-sectional data on musculoskeletal disorders and routine workplace activities from 303 desludging operators in 11 cities in Uganda. These cities were purposively selected based on the presence of a fecal sludge treatment plant or wastewater treatment plant. The Nordic Musculoskeletal Questionnaire (NMQ) was used to assess WMSDs. Simple random sampling with replacements was used to select respondents. Data were analyzed using STATA version 15.0. Modified Poisson Regression was used to measure the strength of association between the independent variables and WMSDs.

RESULTS

A total of 303 study participants were interviewed (97.7% response rate). The average age of the respondents was 34.0 years (SD ± 9.8). The prevalence of WMSDs among desludging operators was 29.7%. The body parts affected by MSDs were; the elbow for 4.6% (14/303), shoulder for 5.0% (15/303), and wrist/hand for 6.3% (19/303) of the respondents. At multivariable analysis, after controlling for age, desludging operators' ability to influence the availability of equipment needed to do their work (APR = 0.45, 95% CI: 0.20-0.99), and feeling that everything done was an effort (APR = 1.70, 95% CI: 1.01-2.87) were significantly associated with WMSDs.

CONCLUSION

The prevalence of WMSDs was high among desludging operators in Uganda. Desludging operators' ability to influence the availability of equipment needed to do their work and frequency of feeling that everything done was an effort were significantly associated with WMSDs. Interventions should focus on ensuring adequate provision of ergonomic equipment and promoting practices that reduce the physical strain associated with desludging tasks. Additionally, comprehensive training programs addressing proper lifting techniques and posture awareness could significantly mitigate the risk of WMSDs among desludging-operators.

Occupational stress and musculoskeletal disorders in firefighters: the mediating effect of depression and job burnout

The firefighting profession carries a heightened risk of musculoskeletal disorders. A firefighter's job is physically demanding and includes activities such as running, climbing, dragging, and lifting. Often, these tasks are unpredictable, performed in harsh environments, and have been found to cause psychological stress. The purpose of this study was to investigate the effects of occupational stress on work-related musculoskeletal disorders (WRMSD) in firefighters. In addition, the mediating effects of depression and job burnout on proposed relationships were examined. Data informing this study were collected using a survey questionnaire. The survey questionnaire included the Beck Depression Inventory, the Center for Epidemiological Studies Depression Scale (CES-D), the Maslach Burnout Inventory, the Post Traumatic Stress Disorder Inventory (PCL), and the Nordic Musculoskeletal Questionnaire. Collected data were analyzed using structural equation modeling approach in AMOS. The results of the 2339 responding firefighters suggest that work related stress is positively related to WRMSDs in firefighters and can lead to musculoskeletal symptoms through four paths, being emotional exhaustion, personal accomplishment, CES-D total score, and depersonalization. Through depersonalization, job stress had the most significant impact on musculoskeletal symptoms (coefficient = 0.053). Furthermore, the results showed that post-traumatic stress disorders (PTSD) can affect musculoskeletal symptoms through ten paths, again through depersonalization, PTSD had the most significant impact on musculoskeletal symptoms (coefficient = 0.141). The results of this study suggest that organizations should design interventions and policies to prevent and manage occupational stress, depression, and job burnout to negate its undesired consequences on firefighters' health (i.e. WRMSD).

Predictive factors of ergonomic behaviors based on social cognitive theory among women workers on assembly lines: application of Bayesian networks

BACKGROUND

This study focuses on identifying the key factors associated with ergonomic behaviors (ERBE) among women workers on assembly lines (WwAL) to prevent musculoskeletal disorders (MSDs) caused by repetitive motions and unfavorable body postures. To achieve this objective, this study employed Bayesian networks (BN) analysis based on social cognitive theory (SCT).

METHODS

A cross-sectional study was conducted to examine the predictive factors of ERBE among 250 WwAL from six different industries located in Neyshabur, a city in northeastern Iran. The study used a two-stage cluster sampling method for participant selection and self-report questionnaires to collect data on demographic characteristics, variables associated with SCT, ERBE, and the standard Nordic questionnaire. The collected data were analyzed using Netica and SPSS version 21, which involved statistical analyses such as independent t-tests, Pearson correlation, and ANOVA tests at a significance level of p < 0.05. BN analysis was conducted to identify the important factors that impact ERBE.

RESULTS

The majority of individuals reported experiencing chronic pain in their back, neck, and shoulder areas. Engaging in physical activity, consuming dairy products, and attaining a higher level of education were found to be significantly associated with the adoption of ERBE p < 0.05. Among the various SCT constructs, observational learning, intention, and social support demonstrated the highest levels of sensitivity towards ERBE, with scores of 4.08, 3.82, and 3.57, respectively. However, it is worth noting that all SCT constructs exhibited a certain degree of sensitivity towards ERBE.

CONCLUSIONS

The research findings demonstrate that all constructs within SCT are effective in identifying factors associated with ERBE among WwAL. The study also highlights the importance of considering education levels and variables related to healthy lifestyles when promoting ERBE in this specific population.

Indexes for motor performance assessment in job integration/reintegration of people with neuromuscular disorders: A systematic review

Individuals of working age affected by neuromuscular disorders frequently experience issues with their capacity to get employment, difficulty at work, and premature work interruption. Anyway, individuals with a disability could be able to return to work, thanks to targeted rehabilitation as well as ergonomic and training interventions. Biomechanical and physiological indexes are important for evaluating motor and muscle performance and determining the success of job integration initiatives. Therefore, it is necessary to determinate which indexes from the literature are the most appropriate to evaluate the effectiveness and efficiency of the return-to-work programs. To identify current and future valuable indexes, this study uses a systematic literature review methodology for selecting articles published from 2011 to March 30, 2021 from Scopus, Web of Science, and PubMed and for checking the eligibility and the potential bias risks. The most used indexes for motor performance assessment were identified, categorized, and analyzed. This review revealed a great potential for kinetic, kinematic, surface electromyography, postural, and other biomechanical and physiological indexes to be used for job integration/reintegration. Indeed, wearable miniaturized sensors, kinematic, kinetic, and sEMG-based indexes can be used to control collaborative robots, classify residual motor functions, and assess pre-post-rehabilitation and ergonomic therapies.

Association between Musculoskeletal Pain and Bone Turnover Markers in Long-Term Pb-Exposed Workers

BACKGROUND

On chronic exposure, Lead (Pb) deposits in the skeletal system, replaces calcium ions, and alters the normal physiological processes, which in turn, lead to stunting, delayed fracture healing, and high resorption of collagen molecules. The present study aimed to assess the association of musculoskeletal pain and discomfort with bone turnover markers (BTMs) among long-term Pb-exposed workers.

STUDY DESIGN

A cross-sectional study.

METHODS

The study recruited 176 male Pb-exposed workers and 80 control subjects who were matched for age, gender, and socio-economic status. Blood lead levels (BLLs), bone growth markers, such as serum osteocalcin (OC), alkaline phosphatase (ALP), bone alkaline phosphatase (BAP), and bone resorption markers: serum pyridinoline (Pry), deoxypyridinoline (DPry), tartrate-resistant acid phosphatase-5b(TRACP-5b), and hydroxyproline in urine (HyP-U) of participants were investigated. Pain and discomfort in the musculoskeletal system were assessed using Nordic Musculoskeletal Questionnaire.

RESULTS

Pb-exposure was significantly associated with musculoskeletal discomfort of the lower back (P<0.001), upper back (P<0.001), and ankle/foot (P=0.011). Among bone formation markers, serum OC was significantly lower in musculoskeletal discomfort of elbows (P=0.033) and ankle/foot (P=0.042). Among bone resorption markers, serum DPry was significantly lower in musculoskeletal discomfort of the neck (P=0.049) and shoulders (P=0.023). HyP-U was significantly higher in musculoskeletal discomfort of shoulders (P=0.035) and lower back (P=0.036).

CONCLUSION

As evidenced by the obtained results, Pb-exposure was associated with musculoskeletal discomfort of the lower back, upper back, and ankle/foot. Lower bone formation (serum OC) marker was noted with musculoskeletal discomfort of elbows and ankle/foot. Furthermore, bone resorption markers were associated with musculoskeletal discomfort of the neck, shoulders, and lower back. The findings of the present study suggested that long-term Pb-exposure and BTMs were associated with musculoskeletal discomfort.