Investigation of musculoskeletal symptoms in a manufacturing company in Brazil: a cross-sectional study

Exploring Musculoskeletal Complaints in a Needle Manufacturing Industry: A Cross-Sectional Study

Musculoskeletal disorders (MSD) encompass a variety of conditions affecting muscles, joints, and nerves. In Portugal, MSDs are the most prevalent occupational health problem in companies. Based on the relevance of work-related MSD (WMSD), this study aims to assess the prevalence of MSD complaints in a needle manufacturing industry in Northern Portugal, following a cross-sectional approach. Thus, 526 workers from five departments (i.e., operator, tuning, maintenance, administration, and logistics) answered a sociodemographic questionnaire and the Nordic Musculoskeletal Questionnaire (NMQ). Within the last 12 months, females exhibited a higher frequency of complaints than males across all body parts except for ankles/feet. The body parts eliciting the most percentage of complaints for both genders include the lower back (54.2%), neck (42.2%), shoulders (39.0%), ankles/feet (38.2%), and wrists/hands (35.7%). No significant association was found between Body Mass Index (BMI) and body part complaints. Tuners reported the highest complaint rate, with occupations as substantial predictors of complaints in certain body parts. Likewise, complaints tend to increase with age. The findings advocate for ergonomic interventions that are gender-, age-, and job-sensitive.

Inequalities in employment and gender differences in the prevalence of work-related musculoskeletal disorders cases: a nationwide survey from Brazil, 2019

OBJECTIVES

The present study aimed to investigate the prevalence of work-related musculoskeletal disorders (WRMDs) and to determine whether differences regarding the employment status (standard and non-standard), according to gender, increased the probability of WRMDs.

STUDY DESIGN

Cross-sectional study.

METHODS

Data from the 2019 National Health Survey (NHS) in Brazil were used. In total, 50,066 participants, both women and men, aged 18-65 years were included. Data were analysed for self-reported WRMDs. The binary logistic regression model, adjusting for possible covariables, was used to evaluate the association between working in the labour market and the occurrence of WRMDs. For covariates in the multivariate analysis, a P-value of <0.20 was considered in the univariate analysis. The variables with a P-value of <0.05 remained in the model. The odds ratio (OR), together with their confidence intervals at 95% (95% CI), were estimates both in the univariate and multivariate models.

RESULTS

The prevalence of WRMDs was higher in women (4.2%) than men (1.9%). The likelihood of WRMDs was associated with the employment status only among men and proved to be lower for non-standard employment than standard employment (OR = 0.61; 95% CI = 0.43-0.87). Only among women, an increase in the likelihood of WRMDs associated with exposure to occupational noise was observed (OR = 1.77; 95% CI = 1.31-2.38) and a less favourable self-reported health (OR = 1.66; 95% CI = 1.08-2.54). Results showed higher change of WRMD for men and women associated with rheumatoid arthritis (men: OR = 3.94; 95% CI = 2.10-7.38; women: OR = 2.39; 95% CI = 1.68-3.39), depression (men: OR = 2.62; 95% CI = 1.54-4.45; women: OR = 2.39; 95% CI = 1.68-3.39) and occupational accidents (men: OR = 4.36; 95% CI = 2.34-8.14; women: OR = 2.20; 95% CI = 1.19-4.07).

CONCLUSIONS

It is possible that the "double presence" that involves both the productive and reproductive spheres explains the higher prevalence of WRMDs among women Indicators that are sensitive to the effects of gender norms are necessary to understand the context of inequalities in the prevalence of WRMDs. The results of this study should be considered when developing strategies in the workplace and public health policies to reduce the prevalence of WRMDs.

Differences in lumbar spine intradiscal pressure between standing and sitting postures: a comprehensive literature review

Background

Musculoskeletal disorders (MSDs), especially in the lumbar spine, are a leading concern in occupational health. Work activities associated with excessive exposure are a source of risk for MSDs. The optimal design of workplaces requires changes in both sitting and standing postures. In order to secure such a design scientifically proved quantitative data are needed that would allow for the assessment of differences in spine load due to body posture and/or exerted force. Intradiscal pressure (IP) measurement in the lumbar spine is the most direct method of estimating spinal loads. Hence, this study aims at the quantitative evaluation of differences in lumbar spine load due to body posture and exerted forces, based on IP reported in publications obtained from a comprehensive review of the available literature.

Methodology

In order to collect data from studies measuring IP in the lumbar spine, three databases were searched. Studies with IP for living adults, measured in various sitting and standing postures, where one of these was standing upright, were included in the analysis. For data to be comparable between studies, the IP for each position was referenced to upright standing. Where different studies presented IP for the same postures, those relative IPs (rIP) were merged. Then, an analysis of the respective outcomes was conducted to find the possible relationship of IPs dependent on a specific posture.

Results

A preliminary analysis of the reviewed papers returned nine items fulfilling the inclusion and exclusion criteria. After merging relative IPs from different studies, rIP for 27 sitting and 26 standing postures was yielded. Some of the data were useful for deriving mathematical equations expressing rIP as a function of back flexion angle and exerted force in the form of a second degree polynomial equation for the standing and sitting positions. The equations showed that for the standing posture, the increase in IP with increasing back flexion angle is steeper when applying an external force than when maintaining body position only. In a sitting position with the back flexed at 20°, adding 10 kg to each hand increases the IP by about 50%. According to the equations developed, for back flexion angles less than 20°, the IP is greater in sitting than in standing. When the angle is greater than 20°, the IP in the sitting position is less than in the standing position at the same angle of back flexion.

Conclusions

Analysis of the data from the reviewed papers showed that: sitting without support increases IP by about 30% in relation to upright standing; a polynomial of the second degree defines changes in IP as a function of back flexion for for both postures. There are differences in the pattern of changes in IP with a back flexion angle between sitting and standing postures, as back flexion in standing increases IP more than in sitting.

[Attentional focus instructions for therapeutic exercise in people with musculoskeletal disorders. A scoping review]

Attentional focus instructions are verbal strategies that could maximize the effects of exercise. The objective of this review was to explore and synthesize the available evidence on the incorporation of attentional focus instruction in the exercise of people with musculoskeletal disorders. A search of 11 databases was carried out until October 2020. Of 4,227 studies identified in the searches, 15 were included. The studies showed deficiencies in the conceptualization and definition of attentional focus instructions. The available evidence indicates that external focus is effective in improving motor learning and function. However, methodological limitations, clinical heterogeneity, the small number of articles included, and new experimental studies challenge the conclusions of the systematic reviews available to date. Attentional focus instructions in musculoskeletal disorders is an emerging field and requires further research. This review is a guide for future studies.

Brazilian Food Handlers' Years of Work in the Foodservice and Excess Weight: A Nationwide Cross-Sectional Study

This study aimed to evaluate the association between the years of work of food handlers in the foodservice and excess weight among Brazilian low-income food handlers. A total of 559 food handlers from all Brazilian regions were characterized using a questionnaire. Weight and height were measured to estimate the Body Mass Index and classify the individuals. The association between food handlers' years of work in the foodservice, anthropometric status, and other variables (gender, age group, educational level, participation in a government program and per capita income at home and energetic consumption) were performed using Pearson's chi-square test (p < 0.05). Multinomial logistic regression analyses were performed (p < 0.05) as well as sensitivity tests using the outcome continuously and transformed, excluding underweight individuals, in a multivariate linear regression model. Most of the sample was female (63.1%), aged between 21 and 40 years old (63.5%), and 53.3% had studied up to complete elementary school. Almost 41% of the food handlers had less than half the minimum wage per capita income. Of the evaluated individuals, 59.9% presented excess weight. There was an association with family per capita income (Odds Ratio - OR: 1.73; Confidence interval - CI95%: 1.09-2.75); handlers whose per capita income was ≤0.5 minimum wage had a 73% higher chance of obesity than those with higher income. Working in foodservive ≥3 years increased the chance of being overweight by 96% compared to those who work for <3 years (OR: 1.96; CI95%: 1.11-3.49). No significant association was found between the years of work of food handlers in the foodservice and obesity. Since work-related factors may contribute to the high prevalence of excess weight, including working in a food handling environment, the government and employers should consider workplace interventions. These would guide the food handlers in avoiding high rates of excess weight and their consequences on public health. Excess weight is an important driver of costs in the workplace associated with absenteeism, job change, and diseases. More studies are necessary to clarify the relationship between the factors related to work and the anthropometric status of food handlers since excess weight is multifactorial.

Effects of workplace upper extremity resistance exercises on function and symptoms of workers at a tertiary hospital: a randomized controlled trial protocol

BACKGROUND

Work-related musculoskeletal disorders (WRMDs) are often caused by inadequate use of the musculoskeletal system during work. Evidence suggests that multimodal intervention through exercises, massage, education, and ergonomic guidelines reduces pain and symptoms in the neck and upper extremities and help to prevent musculoskeletal disorders. The purpose of this study will be to assess the additive effectiveness of a specific and individualized workplace strengthening exercise program to an ergonomic guidance in reducing fatigue, pain and discomfort in the upper extremities and neck perceived by workers.

METHODS

This trial was designed according to the Consolidated Standards of Reporting Trials - CONSORT guidelines. Participants will be employees of a tertiary hospital, with any complaints of pain or discomfort in the upper extremities during the past 12 months, without clinical musculoskeletal diagnosis. 166 participants will be randomized into parallels groups as control and workplace exercises. The primary outcomes will be Numerical Pain Scale, isokinetic muscle strength of abduction and isometric handgrip strength. Secondary outcomes on discomfort, fatigue, work capacity and dysfunction will be assessed by QuickDASH, Patient Specific Functional Scale, Neck Disability Index, Need for recovery, Work Ability Index self-report questionnaires and FIT-HANSA performance test. The Ergonomic Work Analysis will be done by Quick Expose Check, RULA, REBA, RARME, ROSA and HARM risk assessment ergonomic tools. We will analyze the difference between baseline and 12 weeks of intervention by T test of independent samples (95% confidence interval, p < 0.05). Clinical significance will be analyzed by the minimum clinically important difference and effect size by Cohen index. The association between the variables will be analyzed by construct validity with the hypothesis of correlations between pain and muscle strength, strength and functionality and strength and fatigue.

DISCUSSION

Although studies have shown promise outcomes for workplace exercises as an available therapeutic resource used to minimize complaints of pain and discomfort related to work, the results of this study aim to bring evidence about the benefit of a specific resistance exercise as an effective modality to facilitate mechanisms of neuromuscular adaptations, with gradual and posterior hypertrophy in the later phases.

TRIAL REGISTRATION

(NCT04047056, https://clinicaltrials.gov/ct2/show/NCT04047056?term=NCT04047056&draw=2&rank=1 ) on Dec 03, 2020.

Predictors for Clinical Outcomes Related to Upper Extremity Musculoskeletal Disorders in a Healthy Working Population

A wide range of endpoints and methods of analysis can be observed in occupational health studies in the context of work-related musculoskeletal disorders (WMSDs). Comparison of study results is therefore difficult. We investigated the association between different clinical endpoints and the presence of upper extremity WMSDs in a healthy working population. Furthermore, the influence of socio-demographic, work-related, and individual predictors on different endpoints was examined. Two self-administered questionnaires were distributed to 70 workers and employees. In addition, a standardized physical examination and an industry test were performed in this cross-sectional study. Correlations between WMSDs and clinical endpoints were analyzed with the Spearman method and prediction ellipses. Multiple regression models were used to study the strength of associations with a pre-defined set of potential influencing factors. The prevalence of WMSDs was 56% (39/70). Disabilities of Arm, Shoulder, and Hand (DASH) score/pain under strain showed the strongest correlations with WMSDs. When analyzing the correlation between WMSDs and pre-selected predictors, none of the predictors could be identified as a risk factor. The DASH score remains a close candidate for best surrogate endpoint for WMSDs detection. Standardized analysis methods could improve the methodological quality of future occupational health studies.

Self-Reported Variables as Determinants of Upper Limb Musculoskeletal Symptoms in Assembly Line Workers

BACKGROUND

Assembly lines work is frequently associated to work-related upper limb musculoskeletal disorders. The related disability and absenteeism make it important to implement efficient health surveillance systems. The main objective of this study was to identify self-reported variables that can determine work-related upper limb musculoskeletal symptoms-discomfort/pain-during a 6-month follow-up.

METHODS

This was a prospective study with a 6-month follow-up period, performed in an assembly line. Upper limb musculoskeletal discomfort/pain was assessed through the presence of self-reported symptoms. Uni- and multivariate logistic regression analyses were used to evaluate which self-reported variables were associated to upper limb symptoms after 6 months at the present and to upper limbs symptoms in the past month.

RESULTS

Of the 200 workers at baseline, 145 replied to the survey after 6 months. For both outcomes, "having upper limb symptoms during the previous 6 months" and "education" were possible predictors.

CONCLUSION

Our results suggest that having previous upper limb symptoms was related to its maintenance after 6 months, sustaining it as a specific determinant. It can be a hypothesis that this population had mainly workers with chronic symptoms, although our results give only limited support to self-reported indicators as determinants for upper limb symptoms. Nevertheless, the development of an efficient health surveillance system for high demanding jobs should implicate self-reported indicators, but also clinical and work conditions assessment should be accounted on the future.

[Occurrence pattern of musculoskeletal disorders and its influencing factors among manufacturing workers]

OBJECTIVE

To explore the occurrence pattern and its influencing factors of multi-site work-related musculoskeletal disorders (WMSDs) of the main affected body sites among manufacturing workers.

METHODS

Musculoskeletal disorders questionnaire was adopted to investigate the prevalence of WMSDs and the influencing factors among workers from four manufacturing factories in China. The case of WMSDs was defined as the one who had symptoms such as pain, numbness, discomfort, or limitation of activities in one or more of the nine body sites, including neck, shoulder, elbow, wrist/hand, upper back, lower back, hip/thigh, knee and ankle/foot during the last year, which lasted for more than 24 hours and did not completely relieve after rest. Besides, trauma, disability, other acute injuries or sequelae were excluded. The correlation of WMSDs between different body sites was estimated by the prevalence ratio (PR) calculated by log-binominal model. The influencing factors of multi-site WMSDs of the main affected body sites were analyzed by multinomial logistic regression model.

RESULTS

The overall prevalence rate of WMSDs was 79.7% among the manufacturing workers. The main affected body sites were lower back, neck, shoulder and upper back, of which the prevalence rates were 62.3%, 55.7%, 45.6%, and 38.7%, respectively. The PR values of WMSDs among these sites were relatively high. The prevalence of multi-site WMSDs involving these four sites at the same time was 25.2%, and that of three to four sites was 41.4%. Multinomial Logistic regression analysis suggested that influencing factors of multi-site WMSDs in 3-4 sites of neck, shoulder, upper back and lower back involved several aspects. Among these factors, females (OR=2.86, 95%CI 2.38-3.33) and individuals with job tenure of 15-19 years (OR=1.87, 95%CI 1.49-2.34) might have higher risk of disease. Biomechanical factors, such as often bending neck forward or holding neck in a forward position for long periods (OR=2.15, 95%CI 1.86-2.48), often twisting neck or holding neck in a twisted position for long periods (OR=1.64, 95%CI 1.40-1.92) and often twisting trunk heavily (OR=1.40, 95%CI 1.20-1.64) might be risk factors. In the aspect of work organization, doing the same work every day (OR=1.73, 95%CI 1.44-2.08), shortage of workers (OR=1.50, 95%CI 1.31-1.71) and often working overtime (OR=1.38, 95%CI 1.20-1.60) might increase the risk of disease. Factors, such as often standing for long periods at work (OR=0.77, 95%CI 0.65-0.91) and feeling breaks sufficient (OR=0.51, 95%CI 0.44-0.59) were suggested to be protective factors with OR<1.

CONCLUSION

The pre-valence rates of WMSDs in neck, shoulder, upper back, and lower back were high among manufacturing workers in this study. The correlation of WMSDs of these four sites was close in this study, and the comorbidity rate of 3-4 sites of these sites was relatively high, suggesting that there might be a multi-site occurrence pattern of WMSDs in "neck-shoulder-upper back-lower back" among manufacturing workers. The main influencing factors of this pattern included individual factors, biomechanical factors and work organization factors.

Musculoskeletal Disorders and Associated Factors among Vehicle Repair Workers in Hawassa City, Southern Ethiopia

Background

Vehicle repair work is one of the highest risk professions for work-related musculoskeletal disorders. Globally, only a few published studies have examined the prevalence and determinants of work-related musculoskeletal disorders among vehicle repair workers. Related studies in Ethiopia are even fewer. This study aimed to determine the prevalence of self-reported work-related musculoskeletal disorders and associated factors among vehicle repair workers in Hawassa city, South Ethiopia, 2019.

Methods

An institution-based cross-sectional study was conducted among 344 vehicle repair workers in the Hawassa city. The Nordic Musculoskeletal Questionnaire-Extended (NMQ-E) was used to assess work-related musculoskeletal disorders on nine body regions. Descriptive statistics and multivariable analyses were used to characterize the data and identify factors associated with work-related musculoskeletal disorders.

Result

The twelve-month prevalence of work-related musculoskeletal disorders among this working group was 47.7% with 95% CI (42.7-53.2). Jobs continuously requiring repetitive motions (AOR: 4.29, 95% CI (1.78-10.2)), not having professional training (AOR: 2.04, 95% CI (1.09-3.81)), force exertion when using tools (AOR: 2.40, 95% CI (1.24-4.62)), job stress (AOR:4.54, 95% CI (2.44-8.46)), and regularly lifting, pushing, and pulling loads greater than 20 kg (AOR:4.85, 95% CI (2.65-8.87)) were identified as associated factors.

Conclusion

This study showed a 47.7% prevalence of work-related musculoskeletal disorders. Force exertion, repetitive tasks, manual handling of heavy loads, stress, and lack of training were the identified factors. Ergonomic awareness among workers should be increased through training. In addition, owners should investigate methods to reduce or eliminate risk factors leading to musculoskeletal disorders found among these workers. Automation of high-risk tasks should also be investigated.

Is Repetitive Workload a Risk Factor for Upper Extremity Musculoskeletal Disorders in Surgical Device Mechanics? A Cross-Sectional Analysis

To assess the prevalence of upper extremity work-related musculoskeletal disorders (WMSDs) among surgical device mechanics compared to a control group, a total of 70 employees were included and assigned to three occupational groups (grinders, packers, and control). Personal factors, work exposure, manual skill, and complaints were assessed by two self-administered questionnaires and an industry test. WMSDs were diagnosed in a standardised clinical examination. The two-one-sided t-tests (TOST) procedure was used to test the clinical equivalence of the respective grinding and packaging groups vs. the control group in terms of the Disabilities of the Arm, Shoulder and Hand (DASH) score. Thirty-nine study participants (56%) experienced at least one WMSD at the elbow, forearm, and/or wrist, mainly with signs of epicondylitis and nerve entrapment at the medial elbow. The risk of grinders developing upper extremity WMSD was about 2.5-times higher and packers had an 8.6-fold higher risk of a clinically relevant DASH > 29 compared to the control group. However, these differences were not statistically significant. The groups were also proven to be clinically equivalent in terms of DASH score. Surgical device mechanics do not seem to have worse DASH values or be at higher risk of upper limb WMSDs compared to a control group. This is the first study to analyse and compare different workplaces in this industry that are also common in other industries.

Spinal shrinkage, sagittal alignment and back discomfort changes in manufacturing company workers during a working day

Prolonged standing and lifting heavy loads are risk factors for the appearance of low back pain in work. The aim of this study was to observe changes in the height, spinal sagittal alignment, and the lumbar and dorsal discomfort perception in assembly line workers. Cross-sectional study, 40 assembly line workers (6 females). Height, sitting height, grades of thoracic kyphosis and lumbar lordosis and perceived spine discomfort, before and after the working day, were determined. Thoracic and lumbar sagittal alignment was compared between discomfort developers and no developers. There was a significant decrease in the height and sitting height of the workers at the end of the day. Thoracic and lumbar curvature increased significantly, as did the perceived lumbar discomfort. Workers on the assembly line, in a prolonged standing work, suffer an increase in lumbar discomfort, and changes in height and thoracic and lumbar curvatures. Practitioner summary: Spinal shrinkage, sagittal alignment and back discomfort (upper and lower back), were analysed in assembly line workers in prolonged standing during a workday. Assembly line workers suffer a decrease in height, an increase in their thoracic and lumbar curvature, and in lumbar discomfort throughout their workday.

Strength-Duration Curves of Radial Nerve in Patients With Lateral Elbow Pain

CONTEXT

Lateral epicondylalgia (LE) refers to a painful condition at or around the lateral epicondyle of the humerus. LE is one of the most common injuries of the elbow; however, the cause of the pathology is not clear. Patients often experience symptoms consistent with a radial nerve injury; however, data on the involvement of the radial nerve are needed.

OBJECTIVE

To analyze the relationship between electrophysiologic excitability and morphology of the radial nerve in patients with unilateral chronic LE.

DESIGN

Cross-sectional study.

SETTING

Department of Physiotherapy, University of Seville.

PATIENTS

A total of 56 elbows (28 right, 28 left) in 28 patients (12 females, 16 males; age 49 [7.37] y) were recruited by convenience sampling.

MAIN OUTCOME MEASURES

Strength-duration curves (chronaxia and accommodation index) and cross-sectional area (CSA) of the radial nerve were made in all participants. All parameters were compared between both limbs. Also, pain with palpation in the lateral epicondyle and functional pain of involved extremities was assessed using visual analog scale and the Patient-Rated Tennis Elbow Evaluation, respectively.

RESULTS

Symptomatic limb showed higher CSA values of the radial nerve when compared with the asymptomatic limb (P < .001). On the symptomatic limb, duration of symptoms was positively correlated with CSA values. Chronaxia values were all normal and similar between both limbs (P = .35). Regarding accommodation index, 14 (54%) patients showed accommodation indices that suggested pathological radial nerve on the right limb, 4 (14%) on the left limb, 5 (18%) on both limbs, and 4 (14%) had none of the affected nerves. Eight-six percent of patients showed accommodation indices that suggested pathological radial nerve, independently of symptomatic limb. In these cases, affected nerves had higher CSA than the unaffected nerve (P = .01). On the affected nerves, duration of symptoms was positively correlated with accommodation indices.

CONCLUSIONS

These findings suggest that patients with unilateral chronic LE show a decreased excitability in any radial nerve, independently of the symptomatic limb, and that pathological nerves have higher CSA than the nonpathological nerves.