Neck,shoulder and low back pain in secondary schoolchildren in relation to schoolbag carriage: Should the recommended weight limits be gender-specific?

The occurrence of neck, shoulder and low back complaints in relation to schoolbag carriage and other potential risk factors were investigated in a cross-sectional study of 586 Iranian schoolchildren aged 12–14 years. The average load carried by schoolchildren was 2.8 kg. Neck, shoulder and low back complaints during the preceding month were reported by 35.3%, 26.1% and 33% of the students, respectively. Gender was an independent factor predicting musculoskeletal symptoms in schoolchildren. Girls were more likely than boys to suffer from neck, shoulder and low back complaints, although there was no significant difference between genders in terms of schoolbag carriage variables. The findings suggest that the recommended weight limit for schoolbag carriage may need to differ between boys and girls. The associations between schoolbag variables and reported symptoms are also discussed. The results provide evidence that the current weight limit should consider a broader combination of factors that influence the use of schoolbags.     

Physical and mental strain at work: Relationships with onset and persistent of multi-site pain in a four-year follow up

This study evaluates the association of physical and mental strain with the onset and persistence of multi-site musculoskeletal pain among younger and older employees in four-year follow-up. A questionnaire survey was conducted twice in a food processing company, in 2005 and 2009, with responses from 734 employees (445 younger and 289 older; 65% female). Information on musculoskeletal pain during the preceding week and perceived mental and physical strain was obtained through a structured questionnaire. The association of onset and persistent of multi-site pain with mental and physical strain was estimated with log binomial regression analysis and stratified by age group. Risk ratios (RR) with their 95% confidence intervals (CIs) are reported for the estimates. More than 56% of the employees reported multi-site pain at baseline. Among those who reported multi-site pain at baseline 70% reported persistent multi-site pain and one-third reported new onset of multi-site pain at follow-up. Mental strain at baseline strongly predicted persistence of multi-site pain among both younger and older employees (RR from for younger employees = 1.68, 95% CI = 1.01–2.83 and RR for older employees = 2.25, 95% CI 0 1.27–3.98) but the association with physical strain was not statistically significant. Mental strain predicted the risk of persistence of multi-site pain among both younger and older employees in four-year follow-up but not onset of multi-site pain.Relevance to the industryThe results of this study suggest that monitoring working conditions of all age workers can reduce physical and mental strain, thereby reducing the incidence of multi-site musculoskeletal pain and promoting workers' health.     

Demand-specific work ability,poor health and working conditions in middle-aged full-time employees

We investigated the prevalence of reduced demand-specific work ability, its association with age, gender, education, poor health, and working conditions, and the interaction between poor health and working conditions regarding reduced demand-specific work ability. We used cross-sectional questionnaire data from 3381 full-time employees responding to questions about vocational education, job demands and social support (working conditions), musculoskeletal pain (MSP) and major depression (MD) (poor health) and seven questions about difficulty managing different job demands (reduced demand-specific work ability). Reduced demand-specific work ability varied from 9% to 19% among the 46-year old and from 11% to 21% among the 56-year old. Age was associated with two, gender with four, and education with all measures of reduced demand-specific work ability. MSP was associated with four and MD was associated with six measures of reduced demand-specific work ability. We found no interaction between working conditions and poor health regarding reduced demand-specific work ability.     

Musculoskeletal disorders in hospital nurses: a comparison between two hospitals

Nursing staff members of a urban general hospital (GH) and a small oncological department (OD) were surveyed to determine the prevalence of occupational related musculoskeletal disorders (MSDs), the specific disabilities, accidents at work, and working time lost. All subjects had a medical examination to evaluate osteoarthicular disease and selected cases were invited to X-ray examinations. The purpose of this study was to compare MSDs in the two groups of nurses working in two hospitals with different work organization in the same geographical area, Pordenone in Italy. In the previous year 48% GH and 33% OD nurses reported back pain due to work, 29·4 and 16·1% respectively have had X-ray or orthopaedic examinations, 19·2% and 9·1% had been away from work because of back pain. All these differences are statistically significant. The analysis of musculoskeletal pain sites and working tasks in the two hospital workers shows no differences in distribution. Great difference exists when analysing the numbers of patients assisted by a nurse: 0·57 and 1·27 nurse/patients respectively in GH and OD. Our data indicate a high overall frequency of occupational back pain, similar to other studies in Europe. The comparison between the two hospitals suggests factors associated with the disorder: work tasks and particularly nurses/patients ratio are more important factors than age and length of exposure. Different work distribution, shift organization, a better ratio between nurses and patients, an improvement of equipment provision, and specific nurse-training with application of ergonomic methods could improve work efficiency radically and decrease injury rates.     

Assessment of working conditions in two different semiconductor manufacturing lines: Effective ergonomics interventions

This article examines two manufacturing lines producing semiconductors using different technology concepts, namely Conventional Line (CL) and Lean Production Line (LPL). Both lines manufacturing the same products were compared using various factors, including working conditions, task risks and dangers of the job, and physical body stress. Ergonomic approaches were adopted in the investigation of the two lines. Survey questionnaires were administered to 30% of the workers, and multiple statistical tests were used to determine crucial predictors and to investigate the interactions between the factors. This research has shown that improved ergonomics factors will lead to better working conditions and thus increased job satisfaction. The observed ergonomic differences of these two production lines are compared, and appropriate managerial remedial action is recommended. The interventions to both the lines should reduce accident rates, minimize waste of resources, improve work effectiveness, and provide a better working environment that enhances employees' morale and maximizes productivity and profits. © 2010 Wiley Periodicals, Inc.     

Prevention of accidents and injuries in Brazil

After the Second World War, Brazil went through a process of rapid industrialization: industries increased in size and new factories were built. Agriculture, started to diversify, and hand tools were replaced by machinery. As a result, a large number of new workers were needed. As their work tasks were unfamiliar and their training not good, work accidents and injuries at work increased. Statistical records of industrial accidents were started in 1969 and disclosed that in 1970 nearly 18% of industrial workers suffered accidents. A high proportion led to orthopaedic problems, 74-76% being back problems. Statistics for agricultural workers were not available, but a sample study in the state of Sao Paulo disclosed that 9-22% of workers suffered accidents, 54-65% by those working on sugar cane plantations. Preventive measures imposed by legislation were able to reduce these numbers and in 1984 the percentage of industrial workers suffering accidents fell to 3-84%. Legislation regarding the protection of workers from accidents is discussed and examples of the adopted preventive measures are presented.     

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.     

Optimal Duration of Endurance Performance on the Cycle Ergometer in Relation to Maximal Oxygen Intake

The problem was to determine the optimal duration of endurance performance on the bicycle ergometer using max [Vdot]o₂ as the criterion of validity. Max [Vdot]o₂ was measured in 50 male college students using the, step-increment method (the initial resistance was 2·5 at 60 rpm on a bicycle ergometer, and was increased by 0·5 kg each two minutes until the subject would no longer turn.the ergometer, or when the rate fell to 40 to 50 rev/min).,In contrast, the endurance performance test was of the ‘ steady- pace ’ type in which all of the subjects began pedalling at the same initial rate of 69. pedal rpm at a work rate of 1656 kgm/min for 12 minutes. Although the rate of pedalling (and thus the Work rate) declined as fatigue developed, the friction load remained constant at124 kg throughout the test. There were 12 endurance scores for each individual, endurance being measured as the cumulated work done up to a particular minute. The 12 scores ranged from no decrement in the case of a few subjects with complete endurance to 24 percent in the subjeots with least endurance.

The validity correlations (i.e., the min-by-min correlations between, max [Vdot]o₂and the 12 endurance scores), progressively increased to Y = 0·78 at minute 12. An empirical equation of the form, Y =C ? at, was used to fit. a smooth curve to the trend of the correlations so its' changing rate of curvature could be determined quantitatively. The rate of change was found to slow down considerably in the; later stages of performance, especially after minutes 7 or 8, where the change, was less than 0·04 correlation units.

It was concluded that max [Vdot]o₂ does hot predict endurance performance effectively unless the performance is continued for a least 8 minutes under the conditions of the present experiment. With a,12 minute test, the validity is 96 percent of the asymptotic value, suggesting little further gains can be expected beyond 12 minutes.     

A cross-sectional study of self-reported back and neck pain among English schoolchildren and associated physical and psychological risk factors

This study set out to identify the associations between ergonomics and other factors with back and neck pain among schoolchildren. Self-reported questionnaires were used to record health outcomes and potential risk factors in state schools. Six hundred and seventy-nine schoolchildren from Surrey in the United Kingdom aged 11–14 years took part. Twenty-seven percent of children reported having neck pain, 18% reported having upper back pain, and 22% reported having low back pain. A forward stepwise logistic regression was performed with pain categories the dependent variables. Neck pain was significantly associated with school furniture features, emotional and conduct problems, family history of low back pain and previous treatment for musculoskeletal disorders. Upper back pain was associated with school bag weight (3.4–4.45 kg), school furniture features, emotional problems and previous treatment for musculoskeletal disorders. Low back pain was associated with school furniture features, emotional problems, family history and previous injury or accident. It is important to recognise the influence of physical, psychological and family factors in children's pain.     

Perceived physical stress at work and musculoskeletal discomfort in X-ray technologists

A structured questionnaire/interview was designed to explore demographic, personal, occupational and occupational health factors as well as recreational physical activities which can affect X-ray technologists' musculoskeletal symptoms. This questionnaire was piloted for clarity and validity. Subsequently, a random sample of 20 volunteer participants (18 female, 2 male) from two University hospitals were administered the questionnaire in the presence of the investigators to ensure that questions were correctly understood. The data obtained were analysed for magnitude, duration and frequency of activities and for severity, duration and recurrence of morbidity. The X-ray technologists in the sample were found to be a young group of professionals ranging from between 20?–?54 years of age. Eighty-nine per cent of the technologists were physically active and 44% indulged in physical recreational activities. Despite the young age and active life style, the X-ray technologists had significant and diverse musculoskeletal problems; 83% of technologists had backache and 39% of the female technologists had neck pain and 28% shoulder pain. The majority of technologists had suffered multiple episodes of pain. Fifty per cent of the female sample and both male volunteers suffered from upper extremity pain.     

Effects of indicating failure odds and smoothed outputs on human failure detection in dynamic systems∗

One approach to detecting failures in dynamic systems is to run a model in parallel to the real system. In such cases the operator is expected to make decisions about possible failures by comparing the outputs of the system and its model. This task is discussed from the point of view of human information processing. An experiment was run to test different means for aiding the operator in this task. It was found that the detection process may be improved by providing the operator with estimates of the failure odds. Moreover, when both the system and the model outputs were noisy, additional improvement was achieved by providing the operator with pre-smoothed outputs.     

The effects of occupational health and safety management on work environment and health: a prospective study

According to Norway's Internal Control Regulation, all companies are required to have an occupational health and safety (H&S) management system. This study investigated the effects of implementing or improving occupational H&S management on the work environment, H&S-related behaviour and musculoskeletal health of workers in small and medium-sized companies. A one-year prospective cohort study, using self-administered questionnaires, was performed among the managers and blue-collar workers in 226 motor vehicle repair garages. Out of 1559 workers that responded at baseline 721 workers could be identified at follow-up. These 721 workers were included in the study. The workers in companies with improved H&S management from baseline to follow-up reported increased satisfaction with the H&S activities at the garage; improved support from management and colleagues; improved health-related support and control; and increased participation in H&S activities.     

ENERGY REQUIREMENTS OE PRACTICAL JOBS FROM PULSE INCREASE AND ERGOMETER TEST

Abstract

The purpose of this study was to determine whether the angle of the knee joint has an effect on the Fitness Index Scores of the HST. Thirty-three young Caucasoid male subjects were used in this study. The HST was administered in four different knee-joint angles. A repeated measures one-way classification analysis of variance, a one-way classification analysis of variance and an analysis of covariance were used to analyse the data obtained during nine weeks. All tests yielded significant F ratios at the 0·01 level of confidence. Based on these findings, persons who perform the HST in different knee-joint angles have indices which are not measuring cardiopulmonary stress on the same scale. The HST based on standardization of the knee-joint angle promises to increase the evaluating or discriminating power of the test.     

Self-reported musculoskeletal problems amongst professional truck drivers

Occupational driving has often been associated with a high prevalence of back pain. The factors that contribute to cause the pain are diverse and might include prolonged sitting, poor postures, exposure to whole-body vibration and other non-driving factors such as heavy lifting, poor diet or other psychosocial factors. In Europe, truck drivers are likely to be considered an ‘at risk’ group according to the Physical Agents (Vibration) Directive and therefore risks will need to be reduced. This questionnaire-based study set out to examine the relationship between musculoskeletal problems and possible risk factors for HGV truck drivers to help prioritize action aimed at risk reduction. Truck drivers (n = 192) completed an occupational questionnaire with two measures of vibration exposure (weekly hours and distance driven). Items on manual handling, relevant ergonomics factors and musculoskeletal problems were also included. Reported exposures to vibration ranged from 12 to 85 h per week, with a mean of 43.8 h. Distances driven ranged from 256 to 6400 km (mean 2469 km). Most of the respondents (81%) reported some musculoskeletal pain during the previous 12 months and 60% reported low back pain. Contrary to expectations, vibration exposures were significantly lower among those who suffered musculoskeletal symptoms when distance was used as an exposure measure. Manual handling and subjective ratings of seat discomfort were associated with reported musculoskeletal problems.     

Targeting ergonomics interventions--learning from health promotion

Ergonomics often involves encouraging people to accept change, a process affected by their knowledge, attitudes and beliefs. This paper argues that ergonomics projects are likely to have greater success where formal account is taken of these characteristics, and interventions are tailored accordingly. Furthermore, it is suggested that ergonomics can usefully draw upon behaviour change models developed by those concerned with health promotion in the community. One influential model is Prochaska and DiClemente's (Psychotherapy: Theory, Research and Practice, 19, 276-288, 1982) stage of change framework, which describes recipients of health information as progressing through six stages towards stable healthy behaviour: precontemplation, contemplation, preparation, action, maintenance and relapse. This recognises the dynamic nature of behaviour change and that, both within and between individuals, responses may vary from failing to acknowledge existence of a health risk, to where something has already been done about it. Proponents of the model contend that interventions should seek to identify recipients' stage of change and target information and advice accordingly. It is proposed that Prochaska and DiClemente's approach might usefully inform ergonomics activities, particularly when advising with respect to health and safety (e.g. manual handling, upper limb disorders, fall risk, plant safety, etc.) but perhaps also where dealing with other ergonomics considerations (i.e. comfort and performance).     

Prevention of musculoskeletal disorders at work: Validation and reliability in a multicenter intervention study

During the years 1986–1989 The Finnish Work Environment Fund initiated a multicenter, intervention study (programme) to prevent musculoskeletal disorders at work. The programme consisted of four different projects comprising methodological, epidemiological, and interventive themes. The main results were as follows: (1) More than half of the occupational physiotherapists and physicians involved in the project felt that they did not have adequate training for testing the performance capacity of the musculoskeletal system. Several of the most commonly used musculoskeletal tests had either poor validity in predicting future musculoskeletal troubles or had poor reliability. (2) A controlled intervention study showed that active training of neck-shoulder muscles can prevent musculoskeletal troubles, even more than ergonomic actions. (3) It is possible to reduce sick-leave due to low-back disorders by intervention measures directed toward both the work (environment, tools) and the workers (working methods, positive attitude to work, preparedness to keep fit). (4) The identification of ergonomic hazards with the help of teamwork proved to be feasible. The practical improvements, however, were difficult to implement in the prevailing conditions. Some of the improvements increased the work load and the stress of the workers. This aspect needs further consideration.     

Comparisons of tibial accelerations when walking on a wood composite vs. a concrete mezzanine surface

Mezzanine surfaces can be made from concrete, bar grate, or composite materials. Anecdotal data indicate that mezzanines in distribution centers made from composite materials, due to their increased compliance, may be a more comfortable working surface. Prior research suggested that a measure of tibial shock, peak tibial acceleration, could potentially discriminate the biomechanical differences between these surfaces. The objective of this study was to quantify differences in tibial accelerations as 27 people walked on mezzanines constructed from concrete and a wood composite material. Accelerometers were attached bilaterally to the shins of volunteers, and data were collected as they walked 30.5 m on each surface at their normal walking speed, a faster-than-normal walking speed, and a slower-than-normal walking speed. Peak acceleration values obtained from the leg with the highest values were compared. On average, the peak acceleration values were 5% higher on the concrete mezzanine as compared with the wood composite mezzanine (p = .036). These findings suggest that individuals working on mezzanines in distribution centers constructed from composite surfaces would potentially experience less discomfort associated with long exposure periods on these surfaces.     

A randomized and controlled trial of a participative ergonomics intervention to reduce injuries associated with manual tasks: physical risk and legislative compliance

A participative ergonomics approach to reducing injuries associated with manual tasks is widely promoted; however only limited evidence from uncontrolled trials has been available to support the efficacy of such an approach. This paper reports on a randomized and controlled trial of PErforM, a participative ergonomics intervention designed to reduce the risks of injury associated with manual tasks. One hundred and seventeen small to medium sized food, construction, and health workplaces were audited by government inspectors using a manual tasks risk assessment tool (ManTRA). Forty-eight volunteer workplaces were then randomly assigned to Experimental and Control groups with the Experimental group receiving the PErforM program. Inspectors audited the workplaces again, 9 months following the intervention. The results showed a significant decrease in estimates of manual task risk and suggested better legal compliance in the Experimental group.