Assessment of workload and arm position during different work sequences: a study with portable devices on construction workers

It is recognised that work related shoulder pain is overrepresented among construction workers compared to other occupations. Studies have shown that working with hands above shoulder level increases the shoulder load. Most studies have been confined to the laboratory. The present project was carried out to map the muscular engagement and postures of construction workers undertaking ceiling fitting, and to compare the results to those of the laboratory studies. Two ambulatory devices were used, one allowing recording of electromyographic (EMG) signals bilaterally from the trapezius muscle, and the other to record the position of both arms and back by means of measuring the angles between the vertical line and the back and both upper arms. These recordings were performed during 1.5–2 h work sequences. The results show that the work was mostly performed in an upright position, that both arms were used to a similar amount and that the workers for a large proportion of their working time had their upper arms at levels that are considered harmful in view of shoulder load. The EMG data showed that nearly 50% of the work was spent with trapezius activity that exceeded that of the reference contraction used (about 15% of maximal voluntary contraction) and that the time spent in muscular relaxation was 10%. It was concluded that the exposure of construction workers undertaking ceiling fitting meets the criteria formulated on the basis of laboratory experiments with respect to a high risk of acquiring chronic shoulder pain, due to rotator cuff tendinitis.     

Construction of an osteomuscular discomfort scale for the upper region of the body of footwear industry workers

The objective of this study was to build a scale of musculoskeletal discomfort for the upper body of footwear industry workers. The self-reported symptoms of 1821 workers were analyzed via exploratory factor analysis and item response theory. The anatomical regions located in the upper body showed ability to discriminate workers with different levels of musculoskeletal discomfort. A scale with six levels was built, ranging from minimal discomfort to maximum discomfort, with greater precision of discomfort scores between 0 and 3. The region of least discomfort on the scale only indicates rare symptoms in the left shoulder. In the region of maximum discomfort, workers experience symptoms in all regions analyzed on a daily basis, with emphasis on the elbows, neck, trapezius, and middle and upper back. The scale has satisfactory psychometric properties to assess musculoskeletal symptoms in footwear industry workers and can be useful in ergonomic studies.     

Associations of ergonomic and psychosocial work hazards with musculoskeletal disorders of specific body parts: A study of general employees in Taiwan

Background and aimsMusculoskeletal disorders (MSDs) are major occupational health concerns. This study examined the associations of ergonomic and psychosocial work hazards with the risks of MSDs of specific body parts and their distribution across a wide range of occupational groups.MethodsStudy participants comprised 8,937 male and 7,052 female employees aged 20–65 years from a nationwide survey in 2016. A self-report questionnaire was administered to obtain information regarding demographic characteristics, work conditions, ergonomic and psychosocial work hazards, and MSDs of different body parts in 12 months. Multivariate logistic regression models were used to estimate prevalence ratios of MSDs in relation to ergonomic and psychosocial work hazards.ResultsIn professionals and skilled workers, MSDs of the neck and shoulders were more prevalent, whereas in manual workers, MSDs of the hands, wrists, and lower back were more prevalent. Psychosocial work hazards, including high psychological demand and low workplace justice, were major work-related risk factors for shoulder and neck disorders, whereas ergonomic hazards were major work-related risk factors for lower back and wrist or hand disorders.ConclusionDifferent workplace hazards contribute to the risks of different MSDs. To prevent the development of MSDs, occupational health professionals should evaluate both ergonomic and psychosocial work hazards and develop health prevention programs tailored to the risk profiles of working populations.     

The investigation of work-related musculoskeletal disorders among female workers in a hazelnut factory: Prevalence,working posture,work-related and psychosocial factors

BackgroundWork-related musculoskeletal disorders (WMSDs) are the most common occupational health problems in the industrialized world. The identification of WMSDs specific to occupation is essential to plan and implement preventative programs. This study investigated the prevalence of WMSDs and determined the factors related to the severity of the most common disorders among female workers in a hazelnut factory.MethodsA total of 114 female workers were examined in this cross-sectional study using the Nordic Musculoskeletal Questionnaire, the Dutch Musculoskeletal Questionnaire, and an author-developed questionnaire (for socio-demographic characteristics and psychosocial factors). Working posture, craniovertebral angle, thoracic kyphosis angle (TKA), and lumbar lordosis angle were evaluated based on a photogrammetry method using the ImageJ program.ResultsThe prevalence of WMSDs in at least one body part during the last 12 months was 92.1%. The highest prevalence of WMSDs was in the lower back (61.4%), neck (57.9%), shoulder (53.6%), and upper back (45.6%). The least affected part was the elbow. Lower back, shoulder, and neck disorders were the most common causes of activity limitation. The severity of lower back pain was associated with stress in the workplace and work-related factors. The neck pain severity was related to craniovertebral angle and work-related factors. The shoulder pain severity increased with TKA and employment duration. TKA was related to upper back pain severity.ConclusionsWMSDs are common among female workers in a hazelnut factory. Reorganizing of working posture, work-related factors, and stress at work may be beneficial to decrease the prevalence of WMSDs and pain severity.Relevance to Industry; The female workers in the hazelnut factory are vulnerable to the work-related musculoskeletal disorders, particularly in the spinal region. The employers should endeavor to improve the health of the workers by the adjustment of the working posture and environmental factors.     

Musculoskeletal pain among teleworkers: Frequency and associated factors

Teleworking, also known as remote working, has become the new norm for many workers since the coronavirus disease 2019 (COVID-19) pandemic. Studies show that during this time, the incidence of musculoskeletal pain is increasing among these workers. Despite this, few studies have addressed the possible correlates of musculoskeletal paśin in teleworkers, with several potential predictors receiving little or no attention in published studies. With this in mind, an online survey was conducted among organizations in the IT and communications sectors in Malta. Information was collected from 459 teleworkers on the frequency of telework, frequency of work during nonworking hours, exercise frequency, burnout, and ergonomic arrangements. Demographic data were also collected. Results revealed that 55.8% reported one or more musculoskeletal pain. Back pain was the most common, followed by neck and shoulder pain. The presence of pain, the number of painful body areas, and the presence of back, neck, and shoulder pain were each individually associated with work during nonworking hours, lower levels of exercise, and higher levels of burnout. It is argued that musculoskeletal pain appears to be common among teleworkers and may negatively impact the quality of life and organizational performance. Companies and occupational health practitioners should strive to identify the prevalence of these problems among their teleworkers, develop appropriate preventive measures, and support workers to obtain multidisciplinary care when needed.     

Ergonomic,job task,and psychosocial risk factors for work‐related musculoskeletal disorders among teleservice center representatives

A cross‐sectional study was conducted to evaluate the association between work‐related musculoskeletal disorders (WRMDs) and work conditions, perceived exhaustion, job dissatisfaction, and job‐stress issues at two teleservice centers (TSCs). The study covered teleservice representatives who respond to toll‐free calls for assistance. The work involves a computer or manual search for information, and data entry using keyboards. One facility had upgraded the furniture at the workstations; the other facility had not. A questionnaire survey among 114 teleservice representatives and an ergonomic evaluation were conducted to determine WRMDs and their risk factors and perceived job stress. A high prevalence of symptoms of WRMDs was found at both TSCs. Suboptimal ergonomic conditions were associated with neck, shoulder, elbow, and back WRMDs, as well as with increased job dissatisfaction. Perceived increased workload variability and lack of job control were associated with the occurrence of neck and back WRMDs, respectively. WRMDs were more frequently reported by teleservice representatives at the center with older furniture and suboptimal ergonomic conditions. WRMDs may be prevented by improving ergonomic conditions at workstations and addressing work‐organization elements.     

The use of ergonomic measures and musculoskeletal complaints among carpenters and pavers in a 4.5-year follow-up study

The primary aim of this follow-up study was to evaluate the association between the use of ergonomic measures and musculoskeletal complaints among construction workers during an informational campaign on sector level. A questionnaire was sent twice to a cohort of 914 Dutch carpenters and pavers, once in 2000 and once in 2005. Relative risks (RR) were calculated for the regular use of ergonomic measures and regular or sustained lower back and shoulder pain among workers at baseline and 4.5 years follow-up. The response percentages were 78% (n = 469) for carpenters and 64% (n = 202) for pavers. Regular use of specific ergonomic measures varied from 15–66% at baseline to 17–66% at follow-up. Four specific ergonomic measures showed a statistically significant increase in usage. Regular or sustained lower back and shoulder complaints among carpenters decreased from 38 to 34% (p = 0.07) and 24 to 22% (p = 0.18), respectively. Among pavers, lower back (34%) and shoulder (17 to 18%) complaints remained the same or increased. Regular use of a height-adjustable working platform was associated with a lower likelihood of shoulder complaints at baseline (RR = 0.68; 95% CI: 0.46–<1.00) and low back complaints at follow-up (RR = 0.66; 95% CI: 0.50–0.88) among carpenters. Also regular use of aids for handling heavy loads was associated with no shoulder complaints at baseline RR = 0.62 (95% CI: 0.40–0.97) among carpenters. In conclusion, despite a large informational campaign, regular use of ergonomic measures remained low in a 4.5 year period. Regular use of the majority of ergonomic measures was associated, although not statistically significantly, with a lower likelihood of lower back or shoulder complaints. It is recommended to select, apply and monitor powerful implementation strategies to ensure the use of effective ergonomic measures at construction sites.     

Relationship between trapezius load and the incidence of musculoskeletal illness in the neck and shoulder

A relationship between m. trapezius load measured by electromyography (EMG) and the incidence of musculoskeletal illness in the neck and shoulder regions, was investigated both for assembly workers and VDT operators. For assembly workers, the static trapezius load (probability 0.1 of the amplitude probability distribution function, APDF) was significantly reduced from 4.3% MVC (Maximum Voluntary Contraction) to 1.4% MVC as a group median value after an ergonomic adaptation of their work places. Musculoskeletal sickleave was significantly reduced from 22.9 days to 1.8 days as a medium duration per-man-labour year for the same group.

Three groups of VDT operators were examined in terms of trapezius load and pain intensity and duration before and after an ergonomic intervention. All groups reported significant less intensity or duration of pain either in the neck or in the shoulder regions after the intervention. The trapezius load was reduced for all groups post vs. prior intervention. This reduction was measured in terms of a decrease in the static level of APDF and an increase in the number of periods per minute and total duration of muscle activity below 1% MVC. The results from this study indicate that the trapezius load may be a predictor for development of musculoskeletal illness in the neck and shoulder regions.     

Implementation of a participatory ergonomics program in the rehabilitation of workers suffering from subacute back pain

This paper describes a participatory ergonomics program aimed at early return to regular work of workers suffering from subacute occupational back pain and assesses the perceptions of the participants on the implementation of ergonomic solutions in the workplace. The participatory ergonomics program was used in the rehabilitation of workers suffering from subacute back pain for more than 6 weeks, a program that was associated with an increased rate of return to work. The perceptions of the participatory ergonomics participants were assessed 6 months after completion of the ergonomic intervention through a questionnaire sent to employer representatives, union representatives and injured workers of participating workplaces. About half of the ergonomic solutions were implemented according to the perception of the participants, with a substantial agreement between respondents.     

Evaluation of a sitting aid: the back-up

The effects of a portable back support, the Back-Up, were tested in 28 variables. Both subjective and objective physical load measures were recorded during sitting with and without Back-Up, most of them during VDU work. The main result was that the posture of the upper back and neck/head was improved by the Back-Up. However, the knee straps induced unacceptable high pressure and increased significantly the discomfort in the legs. Based on these results the Back-Up was modified: the contact area between the strap and the knee was enlarged. This modified Back-Up was tested again for 13 variables with 10 new subjects. The knee pressure turned out to be acceptable and the discomfort was equal to sitting without the Back-Up. Based on this research the Back-Up is considered as a possible addition to more fundamental ergonomic improvements such as adjustable furniture and variation between sitting, standing and walking tasks, especially for improvement of the neck load. However, the Back-Up should not replace proper ergonomic workstation and work organization design or a backrest on the chair. Furthermore, the Back-Up should not be made obligatory, and it should be worn only for a part of the day, because it limits variation in postures.     

Ergonomic evaluation of work table for waste sorting tasks using digital human modelling

Waste sorting facilities rely heavily on plentiful human labour, and the lack of adequately designed work systems leads to musculoskeletal disorders among the workers. The present research explores the ergonomic design aspects of a cost-effective intervention, a work table for waste sorting in developing countries. This study evaluates the appropriate range of work height for the sorting tasks and proper location of hoppers to drop the sorted items. The ergonomic assessment was conducted by simulating postures involved in sorting tasks in a virtual environment and performing a biomechanical evaluation of the static postures by digital human modelling. Thirty male subjects from Indian population simulated the postures of sorting tasks. The compressive force at L4/L5 intervertebral disc, shoulder flexion moment, shoulder abduction moment, and elbow flexion moment were taken as the indicative parameters of the subject's physical workload. The appropriate table height was marginally lower than the elbow height of the subject and within 4 cm. The preferred hopper position was on the floor adjacent to the worker compared with the hopper on the top of the table.     

Ergonomic on-the-job training of assembly workers. Arm-neck-shoulder complaints drastically reduced amongst beginners

Assembly workers at a chain saw factory in Sweden were ergonomically instructed with the purpose of adjusting their movement patterns so that the muscular load on their upper extremities was kept below the critical level, defined as 10% of the maximum voluntary contraction. The study included two separate categories of subjects: new workers without previous experience of assembly work, and workers with at least one year's experience. As a result of the ergonomic instruction, the number of days lost through arm-neck-shoulder complaints was reduced by half in the test group consisting of new workers, compared with the corresponding control group with no ergonomic training. Amongst the experienced workers, however, the difference between the test group and the control group was statistically non-significant. The study showed that ergonomic monitoring and training are necessary to benefit fully from improved workplaces and tools. Considering the results accomplished amongst the new workers and given the extent of sick leave for the upper extremities, it seems that ergonomic interventions to prevent arm-neck-shoulder complaints at an early stage are extremely worthwhile.     

Long-duration assessment of upper arm posture and motion and their association with perceived symptoms among bakery workers

Awkward shoulder postures have been suggested to be a cause of shoulder discomfort among bakery workers. This study aimed at long-duration assessment of upper arms posture and motion and their association with perceived symptoms among bakery workers. Among workers in three types of bread systems, fifty-seven bakers were randomly selected. The self-reported rates for the perceived severity and frequency of shoulder discomfort were collected through questionnaires. Working postures and movements of the shoulders during work were continuously recorded with inclinometry measurements for three hours. Percentage of time spent with the upper arm right elevated more than 60° was significantly correlated with the perceived discomfort rate in the right shoulder for all bakery workers (r = 0.48 to 0.63, p ≤ 0.05). A significant correlation was found between angular velocity with the perceived discomfort intensity for right upper arm.(r = 0.60 to 0.87, ≤0.005) of all workers in the three baking systems. Physical exposure in bakers was characterized by significantly more awkward postures and the percentage of time spent with the upper arms elevated more than 60°. The current findings can facilitate more informed decisions with respect to both engineering (e.g.ergonomic workstation and tool design) and administration (e.g. work organization) control strategies.     

Effects of changes in sitting work posture on static neck and shoulder muscle activity

Abstract

In order to analyse the effect of changing the sitting posture on the level of neck and shoulder muscular activity, an electromyographic (EMG) study of ten healthy experienced female workers from an electronics plant was undertaken. A standardized, simulated task was performed in eight different sitting work postures. Using surface electrodes, the level of muscular activity was recorded as normalized, full-wave rectified low-pass filtered EMG. The results showed that the whole spine flexed sitting posture gave higher levels of static activity in several neck and shoulder muscles than the posture with a straight and vertical spine, which in turn gave higher levels than the posture with slightly backward-inclined thoraco-lumbar spine.     

Assessing exposure to risk factors for work-related musculoskeletal disorders using Quick Exposure Check (QEC) in taxi drivers

Work-related musculoskeletal disorders (WMSDs) are a common health problem throughout the world. This study aimed to examine the risk factors that are involved in the development of WMSDs in taxi drivers. In total 382 taxi drivers were observed using Quick Exposure Check (QEC) observational tool, which allows practitioners and workers to assess four key areas of the body. Results of the QEC scores were found to be very high for the shoulder/arm, wrist/hand and neck, whereas the scores for the back were found to be high for static use and moderate for moving. The results also showed that the occupational risk factors for WMSDs were associated with restricted postures, repetitive movements, vibration, work related stress. Essential ergonomic interventions are needed to eliminate risk of exposures to WMSDs in taxi drivers.Relevance to industryThe study results have relevance for ergonomists, health and safety practitioners as well as the drivers themselves, and helpful for estimating the main physical risk factors for WMDSs before choosing a method prior to an ergonomic intervention in industry.     

Work-related pains among the workers associated with pineapple peeling in small fruit processing units of North East India

The present study aimed at investigating work-related pain issues among the workers associated with pineapple peeling activity in small fruit processing units of North East India. The study also assessed the associated levels of ergonomic risk prevalent among the workers and identified ergonomic risk factors associated with pineapple peeling task. A cross-sectional survey was conducted using questionnaire-based interview, pain self-report and direct observation of the activities to understand the prevailing work conditions. Rapid Upper Limb Assessment (RULA) was used to assess the level of ergonomic risks involved. Prevalence of pain, in different body parts of the participants, was found evident with a higher percentage of participants reporting pain in shoulders (41.1%), upper arms (37.1%) and lower back (45.7%) while some had also reported of pain in neck (13.2%), lower arms (15.9%), wrists (12.6%) and palm (6%). For RULA, 89.4% of the participants had a grand score greater than equal to 5 which fell under action level 3 indicating for further investigation and changes soon. Hence, various risk factors influencing pain occurrences were identified using logistic regression, and factors like age, gender, hours of peeling, frequency of rest breaks, perceived work fatigue and years of experience, were found to be associated with risk of pain in at least one of the body parts. Identification of these risk factors laid down path for the future course of actions and improvements to address the work pain related issues among workers.Relevance to industryThe study established pain prevalence associated with manual pineapple peeling task and identified the potential risk factors, laying down basis for possible future actions to address work pain related issues and enhance productivity of the workers.     

Cross-sectional study of risk factors for symptoms in the neck and shoulder area

Abstract

This study was performed in order to evaluate how individual characteristics, as well as ergonomic, organizational and psychosocial factors in the work situation are associated with early symptoms in the neck and shoulder area. Nine hundred randomly drawn subjects of the working population in a semi-rural community in Sweden were mailed a questionnaire comprising the Nordic questionnaire on musculoskeletal symptoms, questions on ergonomic, organizational and psychosocial work conditions, life style factors, and background factors. The total response rate was 73% ( n = 637). Questions on ergonomic work conditions and on organizational and psychosocial work conditions provided the measures of exposure. Prevalence ratios (PR) were calculated for symptoms in the neck and shoulder area as reported by 303 subjects. Significant determinants for early symptoms were being a female and being an immigrant, as were repetitive movements demanding precision. High work pace, low work content and work role ambiguity were significant organizational risk factors while life style characteristics did not appear as risk factors. The results suggest that symptoms are signals not only of ergonomic deficiencies in the work situation, but in particular of work organizational conditions. Special attention should be given to the work conditions of women and immigrants in preventive interventions.     

Self reported symptoms in the neck and upper limbs in nurses

This paper describes a cross-sectional study which examines musculoskeletal symptoms in nurses working in two similar units in a residential care centre for the developmentally disabled. Amongst the 30 nurses who were administered the Nordic Questionnaire, neck and upper limb symptoms had resulted in considerable inability to perform work. In contrast, a similar incidence of reported back symptoms in these nurses had not prevented them from doing their work.

An examination of the worker's compensation claims made by nurses from the whole facility showed low back claims to be more common than neck and upper limb claims. It appears that nurses are more likely to make a worker's compensation claim for low back symptoms than neck and upper limb symptoms. In other words, worker's compensation claims do not accurately reflect the types of musculoskeletal symptoms actually experienced by nurses and affecting their ability to do their work.

Five nurses from each unit were also observed during the entire morning and afternoon shifts to examine the work load and the effects of fatigue on the musculoskeletal system. Heart rate measurements and ratings of perceived exertion were taken. Activities performed and types of transfers carried out were also recorded.

Nurses in one of the units had significantly more reported neck and shoulder symptoms than their counterparts. Observations of a sample of five nurses from each unit also showed higher ratings of perceived exertion in this unit. These differences were possibly confounded by the fact that nurses in the unit which experienced these problems were about 8 cm shorter and about 5 kg lighter than their counterparts. Differences in the work practices in the two units, especially methods of manual handling and use of ergonomic interventions were identified as important contributing factors.     

Ergonomics evaluation and redesign of a hospital meal cart

The ergonomic, design and other problems of a conventional hospital meal cart were evaluated with a view to redesign a hospital meal cart by incorporating ergonomic principles and data. The operators encountered difficulty in setting the cart in motion, seeing over the cart, turning the cart and stopping the cart while in motion. The operators expressed postural discomfort in the shoulder, neck, back, lower back, knee and leg, and ankle and foot. The cart with meal trays and food was found to exceed the acceptable initial turning push force requirement of 5th percentile females. Recommendations were made for proper placement of cart handles and handle diameter, provision of large-diameter cart wheel made of hard rubber tire, reduction of cart height, use of plastic material for cart construction, provision of emergency brake, provision of individually (electrically) heated plates for soup and main meal, provision of thick air-tight transparent plastic doors, and reduction of the meal tray size. Several recommendations were adopted by the manufacturer in the new model.     

The effect of a resistance-training program on muscle strength, physical workload, muscle fatigue and musculoskeletal discomfort: An experiment

The aim of the study was to investigate the effectiveness of a resistance-training program on muscle strength of the back and neck/shoulder muscles, relative physical workload, muscle fatigue and musculoskeletal discomfort during a simulated assembly and lifting task. Twenty-two workers were randomized over an 8-week resistance-training group, and a control group. Isokinetic muscle strength was assessed using the Cybex dynamometer, muscle fatigue was measured using EMG, and perceived discomfort was measured using a 10-point scale. At the follow-up, we found no effect of the resistance-training program on isokinetic muscle strength of the back and shoulder muscles. Furthermore, we did not find any effect on EMG data, nor on musculoskeletal discomfort during the simulated work tasks. However, trained workers performed the lifting tasks for a longer time before reporting considerable discomfort than those in the control group.