Overhead work and shoulder-neck pain in orchard farmers harvesting pears and apples

The effects of overhead work were studied by comparing orchard farmers’ musculoskeletal symptoms while bagging pears with those same symptoms while bagging apples. The subjects were 52 Japanese female fanners, who were examined twice an evening in late June for bagging pears, and during another evening of late July for bagging apples, when each task had been almost finished. They were questioned about musculoskeletal complaints of stiffness and pain during each job, and examined for muscle tenderness and pain from joint movement. Arm elevation angles during the work were measured for each type of bagging. The prevalence of stiffness and pain in the neck and shoulder, muscle tenderness in the shoulder regions, and pain in neck motion were found to be significantly higher when bagging pears than apples. Musculoskeletal symptoms of parts other than the neck and shoulder did not differ between the two types of bagging. The working posture of elevating the arm more than 90° was assumed to account for 75% of the time bagging pears, against 40% for bagging apples. Overhead work requiring arm elevation and head extension was considered to be closely related with shoulder-neck disorders among farmers.     

A field comparison of neck and shoulder postures in symptomatic and asymptomatic office workers

Poor neck and shoulder postures have been suggested to be a cause of neck and shoulder pain in computer workers. The present study aimed to evaluate and compare the head, neck and shoulder postures of office workers with and without symptoms in these regions, in their actual work environments. The two all female subject groups reported significantly different discomfort scores across five trials repeated in a single working day. The results of repeated video capture and two-dimensional motion analysis showed that there were trends for increased head tilt and neck flexion postures in the symptomatic subjects (n = 8), compared to the asymptomatic subjects (n = 8). Symptomatic subjects also tended to have more protracted acromions compared with asymptomatic subjects and showed greater movement excursions in the head segment and the acromion. All subjects demonstrated an approximately 10% increase in forward head posture from their relaxed sitting postures when working with the computer display, but there were no significant changes in posture as a result of time-at-work.     

The musculoskeletal system complaints of office workers at a vehicle production factory

This study aimed to determine the prevalence of and factors contributing to musculoskeletal system complaints (MSC) in office workers of a vehicle production factory and absenteeism due to these complaints. A total of 86.2% (n = 333) of the workers completed the survey. Of the workers, 73 (21.9%) were women, and 260 (78.1%) were men, and the mean age was 36.9 ± 8.75 years. The majority of the personnel had more than one symptom with a prevalence of 80.8%. The most frequently observed discomfort was tension and pain in the back muscles (58.6%) and in the neck muscles (58.3%), followed by low back pain (41%) and shoulder pain (30.3%). Pain in the shoulders, neck, and the back and pain and numbness in the fingers were statistically significantly more prevalent in employees who spent more than 5 hours per day performing desk work. Furthermore, all of the complaints, excluding pain in the elbows and knees, were statistically significantly more common in the women. When each complaint and the effects of contributing risk factors were analyzed by logistic regression analysis, pain in the shoulders, neck, and back; pain that spread to the arms; and pain in the fingers were correlated with longer work hours and the female gender (p < 0.05). The number of employees who had used sick leave within the past year due to MSCs was 11.7%. In conclusion, duration of work hours, frequency of breaks, and gender were determined as the most important risk factors in computer users regarding MSCs. © 2011 Wiley Periodicals, Inc.     

Rheumatic complaints among Swedish engine drivers in relation to the dimensions of the driver's cab in the Rc engine

This paper compares the occurrence of rheumatic complaints among male engine drivers with their body measurements and with the dimensions of the cab in the Rc Swedish engine. 150 Swedish engine drivers were interviewed regarding symptoms from the musculoskeletal system. Relevant anthropometric measurements were obtained from each subject and compared with similar dimensions on a symptom free group of drivers matched for age. Data concerning the dimensions of the cab in the Rc engine were obtained from drawings and measurements of the cab. The results indicate that engine drivers with complaints in the lower back, neck and/or shoulders and/or the lower extremities were significantly shorter than controls in those anthropometric measurements related to correct sitting posture. Since the cab of the Rc engine is designed for tall engine drivers, the shorter driver appears to be at risk. Recommendations for cab designs suitable for all potential male and female drivers are appended.     

Work posture,working conditions and musculoskeletal outcomes in agricultural workers

This study evaluated the working postures, working conditions and musculoskeletal outcomes among different agricultural workers in Iran. Data were collected using questionnaires and direct observations of posture (using the Rapid Upper Limb Assessment [RULA] method) from 377 farmers including 150 rice farmers, 122 vegetable growers, and 105 greenhouse workers. The overall prevalence of musculoskeletal symptoms, particularly in the low back (75.1%), knees (62.1%), upper back (61.55%), and neck (59.9%) was very high, and 72.6% of farmers experienced more than three locations of pain/discomfort. The mean RULA grand score of 6.7 highlighted that most farmers needed immediate investigation and changes in their working postures. Being female (neck pain), occupation (rice farmers – low back pain), number of years worked as an agricultural worker (neck and knee pain), prolonged daily working hours (upper back pain), job satisfaction (neck and low back pain), fast working (upper back pain), and working postures (neck, upper back, low back and knee pain) were independently associated with the presence of musculoskeletal symptoms. These findings emphasise the need for multiple component interventions to improve the working conditions of this population.     

New ergonomic problems in mechanized logging operations

A Health Risk Program for forest work has been developed in order to improve health risk identification by systematic evaluation of the relationships between work and health complaints, and to create a base for decisions on different actions to reduce the health risk. This paper deals particularly with logging-machine operators and the problem of the “overload syndrome”, characterized by complaints and injuries to the neck, arms, and cervical spine. The results of health investigations of 1,174 machine operators indicate a prevailing average overload syndrome of 50%, mainly due to one-sided, repetitive, short-cycle working movements with arms and hands.

The analyses show that a whole battery of measures is needed to radically improve this serious situation. Single measures might be positive, but are not enough. To be effective, the full program of measures must be carried out and adapted individually to each machine operator. Improvements in technology/ergonomics are needed, especially regarding the sitting work posture in the cabin, i.e., design of the arms of the chair, controls, and instruments. Important factors are working techniques, micropauses, and physical fitness. New work organization is the most difficult part of the measures to realize in practice, but also the highest potential for improving the situation. Examples of issues to address in this area are design and length of the working shift, job rotation, work tasks and responsibilities, team work, and motivation and payment systems.     

Trapezius muscle activity as a risk indicator for shoulder and neck pain in female service workers with low biomechanical exposure

Electromyographic activity of the upper trapezius muscles was recorded over the workday for two groups of service workers, shopping centre (n = 22) and healthcare workers (n = 44), both with low observed biomechanical exposure. Static and median EMG activity level, number of EMG gaps and gap time were determined. The variability of these variables over the workday was examined by calculating the coefficient of variation (CV) and the intraclass correlation coefficient (ICC) of 1-h consecutive recording periods. All variables except gap time showed acceptable reliability (ICC = 0.69-0.78), i.e. the largest fraction of variance in the data set was due to intersubject variance, despite relatively large hour-to-hour variation (CV = 0.21 0.62). The EMG activity level in the trapezius muscles was low (static activity level < 1% EMGmax), despite the high prevalence of shoulder and neck pain for both groups of workers. In addition to the work recordings, tests were performed to determine intersubject variation in muscle activity when adopting a standardized resting posture, and in a dynamic muscle activity pattern during paced arm movement. Neither the EMG variables from the work recordings nor the tests with EMG recording indicated higher trapezius EMG activity levels for workers with pain in the shoulders and neck in this study. The low EMG levels are interpreted to indicate a low risk of developing shoulder and neck complaints due to biomechanical exposure for both groups of workers. The possibility of pain-initiating mechanisms, associated with stress and not mediated through muscle activity, is considered in the discussion.     

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.     

An assessment of neck and upper extremity disorders by questionnaire and clinical examination

Abstract

To study the usefulness of a screening questionnaire for neck/upper extremity complaints, 165 women in either repetitive industrial, or mobile and varied work, were studied by the questionnaire and by a detailed clinical physical examination. A total of 94 subjects recorded complaintsin the questionnaire. In 140 subjects findingswere recorded at the examination. Most subjects with findings at the clinical examination of shoulders reported complaints in the questionnaire (sensitivity 80%). For the other anatomical regions, the sensitivity was rather low (42– 65%). For all regions, most subjects without findings reported no complaints (specificity 77–97%). A total of 75 subjects were given clinical diagnoses according to a set of predetermined diagnostic criteria. The capacity of the questionnaire to identify diagnoses of shoulders was higher (sensitivity 92%) than for the other regions (66–79%). Of subjects who did not qualify for diagnosis, a majority (specificity 71–81%) did not report complaints in the questionnaire. We conclude that the questionnaire approach gives a fairly good picture of the neck/upper extremity status of a working female population. However, a clear view of the size of a problem is obtained only by a detailed clinical examination, particularly as regards the neck, elbows and hands, for which the questionnaire gave an underestimate.     

Trapezius muscle activity as a risk indicator for shoulder and neck pain in female service workers with low biomechanical exposure

Electromyographic activity of the upper trapezius muscles was recorded over the workday for two groups of service workers, shopping centre (n = 22) and healthcare workers (n = 44), both with low observed biomechanical exposure. Static and median EMG activity level, number of EMG gaps and gap time were determined. The variability of these variables over the workday was examined by calculating the coefficient of variation (CV) and the intraclass correlation coefficient (ICC) of 1-h consecutive recording periods. All variables except gap time showed acceptable reliability (ICC = 0.69-0.78), i.e. the largest fraction of variance in the data set was due to intersubject variance, despite relatively large hour-to-hour variation (CV = 0.21-0.62). The EMG activity level in the trapezius muscles was low (static activity level < 1% EMG_max), despite the high prevalence of shoulder and neck pain for both groups of workers. In addition to the work recordings, tests were performed to determine intersubject variation in muscle activity when adopting a standardized resting posture, and in a dynamic muscle activity pattern during paced arm movement. Neither the EMG variables from the work recordings nor the tests with EMG recording indicated higher trapezius EMG activity levels for workers with pain in the shoulders and neck in this study. The low EMG levels are interpreted to indicate a low risk of developing shoulder and neck complaints due to biomechanical exposure for both groups of workers. The possibility of pain-initiating mechanisms, associated with stress and not mediated through muscle activity, is considered in the discussion.     

Standing working posture compared in pregnant and non-pregnant conditions

During pregnancy, an increase in body weight occurs together with changes in body weight distribution and in fit between body dimensions and workplace layout. These changes may cause alterations in working posture which may, in turn, have adverse consequences for the biomechanical load on the musculoskeletal system and so increase the risk of musculoskeletal disorders. Using photographic posture registration, the standing working posture was studied in 27 women during the last stage of pregnancy and after delivery (the experimental group). The women performed an assembly task while standing at various workplace layouts. The postural differences between the pregnant condition and the non-pregnant condition were studied and the effect of the various workplace layouts assessed. Ten non-pregnant controls were also studied twice to establish the effect of the time interval between the measuring occasions. We found that the women of the experimental group stood further from the work surface in the pregnant condition compared to the non-pregnant condition, the hips were positioned more backwards, and, in order to reach the task, they increased the flexion of the trunk, increased the anteflexion of the upper arms, and extended the arms more. At the workplace layout in which the work surface height was self-selected, the postural differences due to pregnancy were smallest or even absent, compared to the postural differences in the other workplace layouts studied. Ergonomists and workers in occupational health services should be alert to the consequences for the biomechanical load on the musculoskeletal system and the risk of development of health complaints caused by postural changes due to pregnancy. An adjustable workplace layout may prevent some problems.     

Shoulder and neck complaints in customer relations: individual risk factors and perceived exposures at work

Perceived psychosocial and biomechanical exposures, individual factors and pain in the shoulder and neck were recorded in two groups of female service workers (healthcare and shopping centre workers). The jobs investigated were characterized by 'much' direct human relations, 'little' sitting and 'much' standing, and were light work by physiological or biomechanical criteria but potentially psychosocially demanding. A screening survey (n = 400 females) was the basis for the selected sample (n = 66 females), which was the object of the main investigation of this study. Reliability of the questionnaires was tested in a separate group of female healthcare workers (n = 29). Heart rate recordings through the work day estimated workload. There was a high prevalence of shoulder and neck pain (> 50%) for both work groups. In the two populations it proved difficult to explain shoulder and neck pain by reported physical and psychosocial exposures or individual factors, except by the variable 'perceived general tension', which clearly differentiated workers with and without pain. The findings in this study indicated, first, that perceived general tension might be an independent risk factor for muscle pain and, second, that this might be related to personality factors. However, this putative relationship must be verified in a longitudinal study. As no variable describing exposures in the working environment was associated with shoulder and neck pain, the question is posed whether such complaints can be considered work-related. Alternatively, the variables used to describe mechanical and psychosocial exposures in this study may have low specificity in characterizing work-related risk factors for service workers with customer relations.     

Postural and visual loads at VDT workplaces I. Constrained postures

In a field study of 162 VDT and 133 control workplaces it was found that constrained postures of VDT workplaces and in full-time typists were sometimes associated with physical impairments in the hands, arms, shoulders and neck. The reported complaints were confirmed by medical findings on muscles, tendons and joints. The incidence of impairments was increased when the distance from the surface of the keyboards to the desk surface was large; the height of the keyboard from the floor was low; there was insufficient space to rest the forearms and hands; the lateral deviation of the hands operating keyboards was great; and there Was a pronounced inclination or turning of the head. Several recommendations for the proper design of VDT workstations are deduced from the present study     

The biomechanical demands of manual scaling on the shoulders & neck of dental hygienists

Abstract

The purpose of this study was to evaluate the postural and muscular demands placed on the shoulders and neck of dental hygienists when performing a simulated manual scaling task. Nineteen healthy female dental hygienists performed 30-min of simulated manual scaling on a manikin head in a laboratory setting. Surface electromyography was used to monitor muscle activity from several neck and shoulder muscles, and neck and arm elevation kinematics were evaluated using motion capture. The simulated scaling task resulted in a large range of neck and arm elevation angles and excessive low-level muscular demands in the neck extensor and scapular stabilising muscles. The physical demands varied depending on the working position of the hygienists relative to the manikin head. These findings are valuable in guiding future ergonomics interventions aimed at reducing the physical exposures of dental hygiene work.

Practitioner Summary: Given that this study evaluates the physical demands of manual scaling, a procedure that is fundamental to dental hygiene work, the findings are valuable to identify ergonomics interventions to reduce the prevalence of work-related injuries, disability and the potential for early retirement among this occupational group.     

Neck postures in air traffic controllers with and without neck/shoulder disorders

Prolonged computer work with an extended neck is commonly believed to be associated with an increased risk of neck-shoulder disorders. The aim of this study was to compare neck postures during computer work between female cases with neck-shoulder disorders, and healthy referents. Based on physical examinations, 13 cases and 11 referents were selected among 70 female air traffic controllers with the same computer-based work tasks and identical workstations. Postures and movements were measured by inclinometers, placed on the forehead and upper back (C7/Th1) during authentic air traffic control. A recently developed method was applied to assess flexion/extension in the neck, calculated as the difference between head and upper back flexion/extension. Results: cases and referents did not differ significantly in neck posture (median neck flexion/extension: -10 degrees vs. -9 degrees ; p=0.9). Hence, the belief that neck extension posture is associated with neck-shoulder disorders in computer work is not supported by the present data.     

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.     

Upper Body and Finger Posture Evaluations at an Electric Iron Assembly Plant

This study evaluated the postures that workers used to perform 18 different tasks at an electric iron assembly plant by classifying the common simultaneous and individual postures of eight upper body segments and the fingers. The postures of the head, upper arms, lower arms, hand, and trunk were assigned to the categories of “Neutral,” “Bend,” “Twist,” and “Invisible.” The finger postures were also assigned to 14 categories. Overall, most workers bent the head, lower arms, and hands and used power grips to wrap all fingers around parts and tools. The upper arms and trunk were in neutral positions because the workers stood at a conveyor belt. Among 18 tasks, the task of “setting temperature” seemed the lightest work because most body segments were in neutral positions for more than 54.6% of a cycle time, while the task of “palletizing” seemed the most stressful work because all body segments were bent more than 54.4% of a cycle time. These posture differences among the tasks result from the different task characteristics of workplace design, task difficulty, and work duration. It would be useful in designing workplace and evaluating physical workload. © 2012 Wiley Periodicals, Inc.     

Shoulder and neck complaints in customer relations: individual risk factors and perceived exposures at work

Perceived psychosocial and biomechanical exposures, individual factors and pain in the shoulder and neck were recorded in two groups of female service workers (healthcare and shopping centre workers). The jobs investigated were characterized by ‘much’ direct human relations, ‘little’ sitting and ‘much’ standing, and were light work by physiological or biomechanical criteria but potentially psychosocially demanding. A screening survey (n = 400 females) was the basis for the selected sample (n = 66 females), which was the object of the main investigation of this study. Reliability of the questionnaires was tested in a separate group of female healthcare workers (n = 29). Heart rate recordings through the work day estimated workload. There was a high prevalence of shoulder and neck pain (>50%) for both work groups. In the two populations it proved difficult to explain shoulder and neck pain by reported physical and psychosocial exposures or individual factors, except by the variable ‘perceived general tension’, which clearly differentiated workers with and without pain. The findings in this study indicated, first, that perceived general tension might be an independent risk factor for muscle pain and, second, that this might be related to personality factors. However, this putative relationship must be verified in a longitudinal study. As no variable describing exposures in the working environment was associated with shoulder and neck pain, the question is posed whether such complaints can be considered work-related. Alternatively, the variables used to describe mechanical and psychosocial exposures in this study may have low specificity in characterizing work-related risk factors for service workers with customer relations.     

A case study of Taiwanese custom-beverage workers for their musculoskeletal disorders symptoms and wrist movements during shaking task

This study administered the Nordic Musculoskeletal Questionnaire to a convenience sample of 106 workers at custom-beverage vendors in Taiwan (who prepare drinks through manual shaking) to explore their work-related musculoskeletal disorders (WMSDs) and identify risk factors for these disorders symptoms. Wrist posture for twenty workers were also measured for three shaking methods using an electrogoniometer. The prevalence of musculoskeletal discomfort in the past year among the respondents was 88.6%. Most of them reported discomfort in their hands/wrists (67.9%), followed by the lower back/waist (44.3%), knees (39.6%), and shoulders (38.7%). Hands/wrists and low back/waist discomforts varied significantly by the worker's gender and the number of working days per week, and hands/wrists discomfort also by the shaking method. Knee discomfort was affected by age and whether rest periods at work were scheduled, whereas shoulder discomfort by work experience, number of working days per week, and number of drink orders prepared per day. Measurements in wrist postures exhibited that repetitive activity for each wrist was as high as 4 time/s for a cup preparation (10 s). Among shaking methods, curve swing can constrain the shakers' wrists in a relatively neutral position and a smaller range of movement than others, regardless of the sex.Relevance to industryBecause of the nature of shaking-based beverage preparation work, the respondents have a higher prevalence of discomfort in the hands/wrists, lower back/waist, knees, and legs/ankles than their counterparts in other industries. These findings are expected to inform the prevention and alleviation of musculoskeletal discomfort in custom-beverage workers.     

Effect of an intervention addressing working technique on the biomechanical load of the neck and shoulders among hairdressers

The purpose of this study was to describe, and analyse the effect of an intervention on, the biomechanical workload in the neck and shoulder region of female hairdressers. Arm elevation was measured by inclinometers and muscular load of m. trapezius by electromyography. The intervention comprised working technique recommendations, e.g. to work with less elevated arms and more relaxed muscles. The subjects were randomised between two different intensity levels of the intervention, one with written information only and the other with additional personal follow-up. The effect of the intervention was evaluated after 1-2 months. The hairdressers worked with their arms elevated 60 degrees or more for approximately 13% of the total working time and 16% during the specific hairdressing tasks. The intervention group including personal follow-up instructions had a reduction in workload from 4.0% to 2.5% of hairdressing time with highly elevated right upper arm, i.e. above 90 degrees . No effect was detected on muscular load or neck and shoulder symptoms after the intervention.