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Logo of oenvmedOccupational and Environmental MedicineVisit this articleSubmit a manuscriptReceive email alertsContact usBMJ
Occup Environ Med. 2007 December; 64(12): e40.
PMCID: PMC2095402

Musculoskeletal and injuries 3

208 Are occupational factors important determinants for socio‐economic inequalities in musculoskeletal pain?

I. S. Mehlum1, P. Kristensen1, E. Wergeland2, H. Kjuus1. 1National Institute of Occupational Health; 2Directorate of Labour Inspection

ObjectivesSocio‐economic inequalities in health are well documented, and the impact of different determinants needs to be explored. The aim of this study was to quantify socio‐economic inequalities in low back pain, neck/shoulder pain and arm pain in the general working population, and to examine the impact of job characteristics on these inequalities.

MethodsAll economically active 30‐, 40‐, and 45‐year‐old subjects who attended the Oslo Health Study 2000–2001 and answered questions on physical job demands and job autonomy and musculoskeletal pain were included (n = 7293). Occupational class was used as a measure of socio‐economic position. The lower occupational classes were compared to higher grade professionals, and prevalence, prevalence ratios (PR), prevalence differences (PD) and population attributable fractions (PAF) were calculated.

ResultsThere were marked socio‐economic gradients in musculoskeletal pain, steeper in men than in women. The relative differences (PR) were larger for low back pain and arm pain than for neck/shoulder pain. The absolute differences (PD) were largest for low back pain. For non‐skilled workers compared to higher grade professionals, the PD was 25 percent points (pp) in males and 15 pp in females. For neck/shoulder pain and arm pain, the corresponding differences were approximately 15 pp in men and 10 pp in women. Physical job demands explained a substantial proportion of absolute occupational class inequalities in low back pain (22% in male and 49% in female non‐skilled workers), while job autonomy was more important in explaining inequalities in neck/shoulder pain (34% and 25%, respectively) and arm pain (15% and 19%). PAF estimates supported the impact of the job characteristics at the population level.

ConclusionPhysical job demands and job autonomy explained a substantial proportion of occupational class inequalities in musculoskeletal pain in the working population. This suggests the workplace might be an important arena for prevention and thereby reduction of socio‐economic inequalities in musculoskeletal pain.

Key wordssocio‐economic inequalities; musculoskeletal disorders; working conditions

209 Occupational physical activities, working hours and outcome of pregnancy: Findings from the Southampton Women's Survey

M. Bonzin1, K. T. Palmer2, H. M. Inskip2, D. Coggon2. 1Department of Occupational and Environmental Health, Foundation IRCCS Maggiore Hospital, MaRE, Milan, Italy; 2MRC Epidemiology Resource Centre, University of Southampton, Southampton, UK

ObjectivesTo assess the risk of adverse pregnancy outcomes in relation to occupational physical activities and working hours at different stages of gestation.

MethodsWe analysed data from a prospective, community‐based, longitudinal study (the Southampton Women's Survey) on 1327 singleton pregnancies leading to a live birth during 1999–2003 in women who had worked at some time while pregnant. Information about non‐occupational risk factors (parity, alcohol consumption, smoking habits and maternal body mass index) had been elicited at an interview before pregnancy. Data on occupational physical activities (standing/walking >4 h/day, kneeling/squatting >1 h/day, work with trunk bent forward >1 h/day, lifting weights of [gt-or-equal, slanted]25 kg by hand) and working hours ([gt-or-equal, slanted]40 h/week and night shifts) at three stages of pregnancy (11, 19 and 34 weeks) were obtained through an interview at 34 weeks gestation. Information on the baby's gestational age and birth weight was abstracted from hospital records, and head and abdominal circumference were measured by a standardised technique within 48 h of birth. Logistic regression was used to assess associations of occupational exposures with adverse birth outcomes (pre‐term delivery (<37 weeks gestation), small (lowest 10%) for gestational age (SGA), and small (lowest 10%) head and abdominal circumference), after adjustment for possible non‐occupational confounders. Risk estimates were summarised as odds ratios (ORs) with associated 95% confidence intervals (CIs).

ResultsRisk of pre‐term delivery was elevated in women who worked with the trunk bent for >1 h/day, especially at 34 weeks gestation (OR 3.45, 95% CI 1.65 to 7.19), and tended also to be higher in those who carried out heavy lifting late in pregnancy (ORs 1.95 at 19 weeks and 3.45 at 34 weeks). None of the occupational activities was significantly associated with SGA (ORs all <1.3). Small head circumference and small abdominal circumference were both significantly more common in women who worked more for than 40 h/week later in pregnancy (ORs 1.64 to 2.18).

ConclusionOur study points to possible adverse effects of occupational bending, heavy lifting and prolonged working hours late in pregnancy. These findings require confirmation by larger investigations, but suggest a case for precautionary avoidance of these activities.

Key wordsoccupation; pregnancy; physical activity

210 Cultural differences in musculoskeletal symptoms and disability

I. Madan, I. Reading, K. T. Palmer, D. C. Coggon. MRC Epidemiology Resource Centre, Southampton, UK

ObjectivesTo compare the prevalence of common musculoskeletal symptoms and associated disability in groups of workers carrying out similar physical activities in different cultural settings.

MethodsA cross‐sectional survey using an interviewer‐administered questionnaire was undertaken in factories and offices in Mumbai, India, and in the UK. The study participants were three groups of office workers who regularly used computer keyboards (165 Indian, 67 UK of Indian sub‐continental origin and 172 UK white), and three groups of workers carrying out repetitive manual tasks with the hands or arms (178 Indian, 73 UK of Indian sub‐continental origin and 159 UK white).The main outcome measures were hazard ratios (HRs) for the prevalence of symptoms and disability by occupational group, adjusted for differences in sex, age, mental health and job satisfaction.

ResultsReported occupational activities were similar in the three groups of office workers (frequent use of keyboards) and in the three groups of manual workers (frequent movements of the wrist or fingers, bending of the elbow, work with the hands above shoulder height, and work with the neck twisted). In comparison with the Indian manual workers, the prevalence of back, neck and arm pain was substantially higher in all of the other five occupational groups. The difference was greatest for arm pain lasting >30 days in the past year in UK white manual workers (HR 17.8, 95% CI 5.4 to 59.1) and UK manual workers of Indian sub‐continental origin (HR 20.5, 95% CI 5.7 to 73.1). Office workers in India had lower rates of pain in the wrist and hand than office workers in the UK. Only 1% of the Indian manual workers and 16% of the Indian office workers had ever heard of “RSI” or similar terms, as compared with 80% of the UK workers.

ConclusionOur findings support the hypothesis that cultural factors such as health beliefs and expectations may have an important influence on musculoskeletal symptoms and disability. If this is correct, current controls on hazardous physical activities in the workplace may not have the benefits that would be predicted from observational epidemiology.

Key wordsmusculoskeletal; culture; beliefs

211 Significant injuries in Australian veterinarians

M. Lucas. University of Western Australia

ObjectivesHigh injury prevalence has been reported among Australian veterinarians. Factors associated with serious injuries and the reported use of safety precautions when injured is described. Specific objectives: to identify the factors associated with serious injuries and the reported use of safety precautions when injured in Australian veterinarians.

MethodsInjury data from 2800 respondents to a cross‐sectional survey of all veterinary medical graduates from Australian universities from 1960–2001 were reviewed and factors associated with work related significant injuries described. The use of safety precautions when injured is described.

Results2188 significant injuries were reported. Thirty‐two per cent of injuries were treated in hospital with 50% of those requiring admission. Thirty‐seven per cent of injuries occurred whilst undertaking procedural activity, 21% whilst examining animals and 15.3% whilst moving or restraining an animal. Hand injuries were the most common bodily location of injury (33% of respondents), followed by injury to the rest of the upper limbs (12.7%) and the face (9%). Thirty‐six per cent of veterinarians reported treatment for open wounds, 15.3% for reduction of fracture/dislocation, and 13% for soft tissue injury/bruising in their career. Sixty‐three episodes of intracranial injury were reported and there were 19 traumatic amputations. Bites by animals (25.7%), kicks or strikes (28%), animal contact (12.2%) and cutting or scratching (7.6%) were the most common mechanism of injury. The major animals involved included cattle (21.7%), horses (20.7%), dogs (19.8%) and cats (7.7%). Motor vehicles were associated with 6.5% of serious injuries reported. Fifty‐five per cent of veterinarians reported the use of safety precautions when injured. Restricting enclosures such as cattle crushes (13%), animal restraints (11.7%), physical restraints (8.0%) and animal sedation (4.5%) were the most commonly described safety precautions in use at the time of injury.

ConclusionThe major factors associated with significant injuries and the use of safety precautions when injured are described. The findings reported should enable a better understanding of the risk factors associated with these injuries and enable more targeted injury prevention measures appropriate for this high risk occupational group.

Key wordsveterinarians; injury; safety precautions

212 The effect of industrialisation on injury rates in SE Asia: the lessons from a 100% sampling strategy

H. MarucciWellman1, T. B. Leamon1, B. T. T. Tuyet2, B. D. Nguyen2, D. K. Kriebel3, D. H. Wegman4. 1Liberty Mutual Research Institute for Safety; 2National Institute for Occupational and Environmental Health; 3Department of Work Environment, University of Massachusetts Lowell; 4University of Massachusetts Lowell

ObjectivesLittle is known about the effects of development on injury risk in developing countries because surveillance systems rarely exist. We conducted a surveillance study based on a 100% sample of Xuan Tien Commune in Vietnam. Our objective was to understand the impacts of industrialisation on the types of work, workloads, hazards and work‐related injuries in one commune.

MethodsThe first phase of surveillance included a 100% household survey administered by 21 volunteers. Information was collected on the characteristics of all businesses and all formal and informal work for each family member. Each family member's work history was partitioned by hours worked in each job in the last year. The head of household was asked to report on anyone in the household who was “hurt” (selected as better approximation of “injury”) in the last month. An additional questionnaire gathered detailed characteristics for those reporting an injury.

Results2612 households (99% response) completed the survey. For the 603 “hurts” reported in the last month (annualised IR 69.3/100 residents), 81% occurred while working or commuting to/from work (annualised IR 102.4/100 full time employee equivalents (FTE)). The highest incidence rate was in manufacturing (IR 126.7 per 100 FTE), with agriculture second (IR 86.0 per 100 FTE). Sixty per cent of cases lost at least 1 day of work.

ConclusionWork and home life are extremely intertwined in Vietnam. Workers have complex working schedules. Often, agriculture and manufacturing are carried on simultaneously, and many residences also house manufacturing activities. While many injuries occur in the “home”, the hazards are often unsafe work conditions. Over 80% of all injuries reported in this study were attributed to work tasks, a much higher incidence of work‐related injury than previous estimates for Vietnam. Possible reasons for higher rates include clear definitions of injury (“hurt”) as well as work, and the use of health volunteers – respected, dedicated members of the community. Partitioning risk by work tasks through careful quantification of work hours also increased the accuracy of these data. Increased industrialisation, including more manufacturing work, will increase the risk of injury in Vietnam until work conditions are improved.

Key wordsinjury; surveillance; industrialisation

213 Retinal detachment and manual lifting: a case‐control study in myopics

S. Mattioli1, R. De Fazio2, E. Buiatti3, D. Truffelli4, F. Zanardi4, B. Miglietta4, S. Curti1, A. Baldasseroni5, G. Tassinari2, F. S. Violante1. 1Unit of Occupational Medicine, University of Bologna; 2Department of Ophthalmology, Ospedale Maggiore, Bologna; 3Regional Health Authority of Tuscany, Florence; 4School of Occupational Medicine, University of Bologna; 5Unit of Epidemiology, Local Health Authority, Florence

ObjectivesRetinal detachment is separation of the neurosensory retina from the retinal pigmental epithelium which can lead to blindness. Identification of risk factors and predisposing lesions for retinal detachment is important for primary prevention. The aim of this study was to investigate the hypothesis that repeated lifting tasks could be a risk factor for retinal detachment in the presence of myopia (a major risk factor for this pathology).

MethodsIn our case‐control study, a total of 120 patients, surgically treated for retinal detachment, responded to the questionnaire (response rate, 89%). 61 respondents (26 (43%) women and 35 (57%) men) who had some degree of myopia were classified as cases. For the control group, we were able to screen all 99 subjects (49 (49%) women and 50 (51%) men) with myopia (of any degree) who underwent outpatient examination at three National Health Service ophthalmologic surgeries located within the hospital's catchment area (response rate, 100%).

ResultsMean age (SD) was 56 (18) years for cases and 55 (15) years for controls. Mean degrees of myopia were 5.5 (4.7) in cases and 4.5 (2.5) in controls. Mean BMI (SD) was higher in cases than controls (25.4 (3.8) vs 23.5 (3.1) kg/m2, p<0.001). The logistic regression model (adjusted for age, sex, ocular surgery/trauma and degree of myopia), showed a significantly increased risk for heavy manual lifting (OR 4.6; 95% CI 1.6 to 13.2) and also for overweight (OR 4.0; 95% CI 1.1 to 14.3) and obese (OR 5.6; 95% CI 1.6 to 20.4) subjects. Notably, out of 13 almost‐obese (and obese) subjects executing manual lifting, 12 were cases; on the other hand, out of 26 subjects within a normal BMI range and not executing manual lifting, 24 were controls. Hence, overweight subjects exposed to heavy lifting appeared to have a 144‐fold higher risk (point estimate) of retinal detachment.

ConclusionThe rupture of retinal capillaries after Valsalva's manoeuvre and the intraocular pressure spikes caused by heavy manual lifting could explain the increased risk shown for subjects executing such tasks. Obese heavy‐manual workers were particularly at risk, possibly because of the higher physical effort. These observations could be of relevance for prevention of this socially important pathology.

Key wordsretinal detachment; lifting; obesity

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