Promoting safety of underground machinery operators through participatory ergonomics and fuzzy model analysis to foster sustainable mining practices.

One of the most vital parameters to achieve sustainability in any field is encompassing the Occupational Health and Safety (OHS) of the workers. In mining industry where heavy earth moving machineries are largely employed, ergonomic hazards turn out to be significant OHS hazards causing Musculoskeletal Disorders (MSDs) in the operators. Nevertheless, the Indian mining industry lacks a comprehensive technique of OHS risk assessment, especially for ergonomic hazards that cause MSDs. This research appraises ergonomic hazards and develops Fuzzy Musculoskeletal-disorders Index (FMI) model to evaluate ergonomic-related MSDs. Work process and work tool ergonomic risk factors were identified through literature review and directives recommended by experts. Work posture was evaluated using RULA. The data-collecting approach was implemented using participatory ergonomic and design science principles. The FMI results show average MSDs score of 3.69, indicating high to extremely high risk. Surface plots show that combined work tool and work process was the most sensitive factors to MSDs risk compared to other two combinations. A two-sample t-test validated the FMI. The findings should help safety experts and managers develop effective OHS management plans and programmes for the sustainability of Indian mining industry.

Do energy expenditure differences across work postures influence cognitive processing speed? A counter-balanced randomised cross-over trial.

BACKGROUND: Anecdotal evidence links occupational sedentary behaviour, low energy expenditure (EE) and cognitive dysfunction. Nevertheless, EE across different work postures including active workstations remains unclear and its influence on cognitive processing speed is yet to be established. OBJECTIVE: We aimed to investigate differences in EE across various work postures and its influence on cognitive processing speed. METHODS: Sixteen desk-based employees performed simulated work tasks (typing, reading and cognitive tasks) in three different work positions (sitting, standing, and walking) in three different days. EE was measured for three days consecutively for 30-minutes in three simulated working postures using indirect calorimetry. Cognitive processing speed was assessed through computer-based choice reaction times during each work posture. The outcome variables of interest (EE, reaction times and accuracy) were compared between three work postures using repeated measures ANOVA and Pearson correlation. RESULTS: EE in walking posture was higher (5.57±0.45 Kcal) than sitting (1.07±0.12 Kcal) and standing (1.88±0.42 Kcal). Total EE was significantly higher in walking than standing (35.17±6.86 Kcal) and sitting postures (41.37±8.46 Kcal). We did not find any significant differences in cognitive processing speed between different work postures except within standing work condition (60.22±13.97 ms). Accuracy was found to be reduced in walking compared to sitting (0.76±0.83%) and standing (0.43±0.09%) but not reached significance. CONCLUSION: Although significant differences in EE were observed between work postures, walking or standing at work did not affect the cognitive processing speed.

Relation of body mass index and work posture to musculoskeletal disorders among fishermen.

OBJECTIVE: In this study, we researched to determine the relationship between body mass index (BMI) and work posture/position with the musculoskeletal disorders (MSD) in fishermen. METHOD: This type of research is analytic survey research with a cross-sectional study. There were 224 people as the population in this study with 56 samples as respondents. Nordic Body Map (NBM) and Rapid Entire Body Assessment (REBA) were used as a questionnaire instrument. RESULTS: The result of the Chi-square test shows that the BMI variable has a p-value of p=0.848 where the p-value is p>0.05. This means BMI has no significant relationship with MSD. Meanwhile, the work posture/position variable has a p-value of p=0.000 where the p-value is p<0.05, which means that there is a significant relationship with MSD. CONCLUSIONS: BMI was not associated with MSD. This is possible because fishermen who have normal and abnormal BMI both have complaints of MSD. Meanwhile, work posture/position has a significant relationship with complaints of MSD in fishermen. This is because the posture of fishermen when working with tools when doing research looks very risky.

Intraoperative musculoskeletal discomfort and risk for surgeons during open and laparoscopic surgery.

BACKGROUND: Surgeon workload is significant both mentally and physically and may differ by procedure type. When comparing laparoscopic surgery and open surgery, studies have reported contrasting results on the physical and mental workload assessed. METHODS: Wearable posture sensors and pre-/post-surgical questionnaires were employed to assess intraoperative workload and to identify risk factors for surgeons using objective and subjective measures. RESULTS: Data from 49 cases (27 open and 22 laparoscopic surgeries performed by 13 male and 11 female surgeons) were assessed. More than half the surgeons reported a clinically relevant post-surgical fatigue score. The surgeons also self-reported a significant increase in pain for the neck, upper back, and lower back during/after surgery. Procedural time had significant impacts on fatigue, body part pain, and subjective (NASA-TLX) workload. The objectively assessed intraoperative work postures using wearable sensors showed a high musculoskeletal risk for neck and lower back based on their posture overall. Open surgeries had significantly larger neck angles (median [IQR]: 40 [28-47]°) compared with laparoscopic surgeries (median [IQR]: 23 [16-29]°), p < 0.001) and torso (median [IQR]: 17 [14-22]° vs. 13 [10-17]°, p = 0.006). CONCLUSION: Surgeons reported significantly higher levels of fatigue and pain in the neck and lower back during or after performing a surgical case. Longer procedural time resulted in more self-rated fatigue, pain, and subjective workload. Open surgery had higher postural risk. Overall, surgeons spent a disturbingly high percentage of time during surgery in high-risk musculoskeletal postures, especially the neck. These results show that intraoperative postural risk is very high and that interventions are necessary to protect surgeon musculoskeletal health for optimal surgeon performance and career longevity.

A 10-week exercise intervention can improve work posture but not neck/shoulder symptoms in dental health students: A pilot cohort study.

BACKGROUND: Dental workers including dental health students experience a high incidence of neck/shoulder symptoms. However, research into interventions has been scarce and largely focused on tools and technological modifications. OBJECTIVE: This study investigates the feasibility and benefits of a neck/shoulder exercise intervention on work posture and local symptoms in dental health students. METHODS: Twenty-three students participated in a 10-week resistance exercise program for 2 minutes daily, 5 days per week. Work posture (evaluated with the Rapid Upper Limb Assessment tool, RULA), muscle strength measures, self-rated symptom severity and function were collected. Feasibility of the intervention was determined with six items scored on a 5-point Likert scale. RESULTS: The exercise intervention improved: work posture score by 1.88 (95% CI 1.05-2.70, p < 0.01) points on the RULA; isometric maximal strength of neck flexor and extensor muscles by 17.2% (95% CI 6.9-27.6%, p < 0.01) and 23.2% (95% CI 10.2-36.3%, p < 0.01) respectively; and clinical performance (77%). Isometric strength of the shoulder muscles, and symptom severity at the neck/shoulder showed no improvement. Adherence to training was 77%. CONCLUSION: Ten weeks of exercise was feasible for dental health students, and likely beneficial with improvements in work posture and neck muscle strength.

Factors affecting musculoskeletal disorder prevalence among women weavers working with handlooms in Samarinda, Indonesia.

A cross-sectional study was conducted on 40 women weavers of Samarinda sarongs to identify the prevalence and risk factors of musculoskeletal disorders (MSDs). A Nordic body map, rapid upper limb assessment and anthropometric tools were used to plot the MSD severity, work posture and anthropometric dimensions of the weavers, respectively. The age, education background, working period and prolonged sitting position distributions of the weavers were collected by direct interview. Pearson's product-moment correlation was applied to identify correlations between the MSD prevalence and other parameters. An MSD prevalence of 80.5% was found among the women weavers, with the MSDs categorized as low, moderate and high in 15.0, 75.0 and 7.5% of the respondents, respectively. The MSD prevalence was significantly correlated with education background (p = 0.025), working period (p = 0.015), prolonged sitting hours (p = 0.032), work posture (p < 0.001) and weavers' anthropometry (p < 0.001).

The impact of a change in work posture from seated to stand-up on work-related musculoskeletal disorders among sewing-machine operators.

BACKGROUND: Work-related postural change could lead to improved musculoskeletal health. METHOD(S): In a quantitative, retrospective, longitudinal study, data of work-related musculoskeletal disorders of 123 sewing-machine operators were captured for 4.5 years, and analysed using Poisson regression. RESULTS: Stand-up work posture (SUWP) reduced the incidence for spinal disorders (SD) to 0.29 fold the incidence for sitting work posture (SWP) (P < 0.001). Morbid obesity had significantly increased (P = 0.04) incidence of upper limb disorders (ULD), 3.35 times that of normal body mass index (BMI) (regardless of work posture). SUWP was associated with increased IRR (1.49) for lower limb disorders (LLD). LLDs were associated with obesity (overweight (IRR = 2.58; P = 0.08), obese (IRR = 2.45; P = 0.09), and morbidly obese (IRR = 6.24; P = 0.001)). CONCLUSIONS: The protective benefit of the SUWP was statistically significant for SD incidence. Owing to high mean BMI, SUWP had a negative impact on the incidence of LLDs for the first 2 months.

Dental Students' Perceptions of Risk Factors for Musculoskeletal Disorders: Adapting the Job Factors Questionnaire for Dentistry.

The aims of this study were to adapt the Job Factors Questionnaire to the field of dentistry, evaluate its psychometric properties, evaluate dental students' perceptions of work/study risk factors for musculoskeletal disorders, and determine the influence of gender and academic level on those perceptions. All 580 students enrolled in two Brazilian dental schools in 2015 were invited to participate in the study. A three-factor structure (Repetitiveness, Work Posture, and External Factors) was tested through confirmatory factor analysis. Convergent validity was estimated using the average variance extracted (AVE), discriminant validity was based on the correlational analysis of the factors, and reliability was assessed. A causal model was created using structural equation modeling to evaluate the influence of gender and academic level on students' perceptions. A total of 480 students completed the questionnaire for an 83% response rate. The responding students' average age was 21.6 years (SD=2.98), and 74.8% were women. Higher scores were observed on the Work Posture factor items. The refined model presented proper fit to the studied sample. Convergent validity was compromised only for External Factors (AVE=0.47), and discriminant validity was compromised for Work Posture and External Factors (r2=0.69). Reliability was adequate. Academic level did not have a significant impact on the factors, but the women students exhibited greater perception. Overall, the adaptation resulted in a useful instrument for assessing perceptions of risk factors for musculoskeletal disorders. Gender was found to significantly influence all three factors, with women showing greater perception of the risk factors.

Infrared thermography reveals effect of working posture on skin temperature in office workers.

INTRODUCTION: Musculoskeletal symptoms related to using traditional computer workstations are common. Quantitative methods for measuring muscle stress and strain are needed to improve ergonomics of workstations. We hypothesize that infrared thermography (IRT) is suited for this purpose. METHODS: This hypothesis was evaluated by estimating muscle activity in upright and traditional working postures with IRT and surface electromyography (sEMG). IRT and sEMG measurements were conducted in 14 female participants with both working postures. First, measurements with the traditional posture were performed. Later, participants had 1 month to adjust to the upright working posture before repeating the measurements. IRT images were acquired before and after a full working day, with sEMG recordings being conducted throughout the measurement days. Participants evaluated their neck pain severity using neck disability index (NDI) questionnaires before the first and after the second measurement day. RESULTS: Spatial variation in upper back temperature was higher (p = 0.008) when working in traditional posture and the upright working posture reduced (p < 0.05) upper back muscle activity. The NDI was significantly lower (p = 0.003) after working in the upright posture. CONCLUSION: IRT was found suitable for evaluating muscle activity and upright working posture to reduce the NDI and muscle activity in the upper back.

Evaluation of Work-Related Musculoskeletal Disorders and Postural Stress of Female "Jari" Workers.

AIMS: The present investigation was aimed to assess the postural stress and the prevalence of musculoskeletal disorders (MSDs) of the "Jari" (golden thread) workers. SETTINGS AND DESIGN: This cross-sectional study was carried out on 156 female workers in different areas of the Purba Medinipur, Paschim Medinipur, and Howrah districts of West Bengal, India. MATERIALS AND METHODS: The MSDs of the workers were evaluated by modified Nordic questionnaire method. The postural pattern during work was assessed by direct observation method. The posture of Jari workers has been analyzed by OWAS, REBA, and RULA methods. The joint angle in normal and working posture was observed. RESULTS AND CONCLUSIONS: The prevalence of MSDs was very high among the workers. The major locations of body pains in Jari workers were lower back, upper back, neck, wrist, thigh, and shoulder. The occurrence of MSDs was higher in lower and higher age group than that of the middle age group. The total work shift of the workers was approximately 13 h including rest pause. The dominant postures adopted by the workers were sitting on the floor with stretched legs, sitting on the floor with folded knees, and kneeling posture. From the results of the postural analysis, the postures of the Jari workers had been categorized as stressful. There were a significant deviation between normal standing angles and working angles. From the overall study, it may be concluded that adoption of stressful postures for longer duration might be the cause of MSDs in different body parts of the Jari workers.

Optimal correction in spectacles: intervention effects on eyestrain and musculoskeletal discomfort among postal workers.

BACKGROUND: The static posture of postal workers when sorting mail can lead to musculoskeletal discomfort. Research has shown a connection between eyestrain and upper-body musculoskeletal discomfort in general, including postal workers. A previous study of postal workers found that most of those with eye strain were in need of a new correction in their existing spectacles. OBJECTIVE: Evaluate intervention effects on eyestrain and musculoskeletal discomfort with new spectacles for postal workers. METHODS: Postal workers subjectively reported eyestrain, musculoskeletal discomfort and their opinions of the visual environment via questionnaires pre- and post-intervention. After an eye examination the postal workers were divided into two groups: those who needed new spectacles and those who did not. RESULTS: Those who needed new spectacles showed a higher prevalence of eyestrain and musculoskeletal discomfort pre-intervention. Post-intervention, the postal workers rated their vision better and the average eyestrain and musculoskeletal discomfort decreased for both groups. These workers also experienced a decrease in discomfort on the left (static) side of the neck while sorting mail. CONCLUSION: An intervention providing the optimal correction reduces eyestrain and decreases musculoskeletal discomfort, especially from the neck.

Avaliação da postura e posições de trabalho do cirurgião-dentista destro e da auxiliar odontológica em procedimentos restauradores / Evaluation work of posture and positions of the right hand dentist and chairside assistant in restorative procedure

O presente estudo analisa a postura e posições do cirurgião-dentista destro e da auxiliar odontológica, bem como a posição da cabeça do paciente, para restaurações em amálgama e resina composta, usando os princípios ergonômicos no trabalho. As observações foram realizadas nos dentes anteriores e posteriores, tanto na maxila como na mandíbula. Para atingir este objetivo, para todas as restaurações realizadas, foram registrados fotograficamente: a) a postura e as posições para o cirurgião-dentista destro; b) a postura e posições para a auxiliar odontológica; c) o posicionamento da cabeça do paciente; d) a região de apoio das mãos do cirurgião-dentista; e) o afastamento de tecidos moles quando realizado pelo dentista. De acordo com as observações, julga-se oportuno concluir que: a) as posições ideais para o cirurgião-dentista são de 9 e 11 horas; b) a posição ideal para a auxiliar atuar diretamente na boca do paciente é a de 3 horas; c) o posicionamento da cabeça do paciente está diretamente relacionado à região da boca onde está sendo realizada a restauração; d) a mão direita do cirurgião-dentista manteve-se apoiada no polegar esquerdo; a mão esquerda realiza o afastamento de lábios e bochecha

In this study an analysis about the work postura and positions of the right-hand operator and of the chairside assistant was made, as well as the patient's head position, for amalgam and composite restoration using ergonomic principles in the work. The observations were done for anterior and buccal teeth of either the maxilla or the mandible. To reach this objective, for all restorations the following situations were photographed: a) the right hand dentist's posture and positions; b) the chairside assistant's posture and positions; c) the patient's head position; d) the rest position of the operator's hands; e) the separation of the soft tissue when performed by the dentist. According to the observations the following conclusions were drawn: a) the ideal positions for dentist are the 9 and 11 o'clock; b) the ideal position for chairside assistant to operate directly on the patient's mouth is the position of 3 o'clock; c) the positioning of the patient's head is directly associated with the area of the mouth in which it is being performed the restoration; d) the right hand of the dentist had been supported by the left thumb; the left hand separates the lipas and bucca

Anterior chest support, muscular activity and subjective rating of exertion during microtome sectioning.

Seven females, six laboratory assistants, participated in the experimental part of the study. The level of muscular activity in different sitting work postures was recorded, using surface electrodes, as full-wave-rectified and low-pass filtered EMG, and normalised. The laboratory assistants also rated the degree of exertion in four different body regions during their ordinary microtome sectioning work, comparing the use of anterior chest support with the use of their usual chair with lumbar support. The use of anterior chest support reduced the muscular activity in the lumbar back muscles but increased it in the shoulder muscles. Perceived exertion in the neck, shoulders and thoracic back regions increased. Anterior chest support does not seem to solve the problem of neck- and-shoulder load-elicited pain during the work of preparing laboratory sections.