Ewa Wigaeus Hjelm

Occupational and individual factors related to musculoskeletal symptoms in five body regions among Swedish nursing personnel.

The relationship between individual factors, physical and psychosocial exposure at work, and musculoskeletal symptoms in the neck, shoulders, low back, hands, and knees was studied among female nursing personnel working at a Swedish hospital. The personnel had participated in a course in work technique (patient transfer and handling principles). Prior to the course, the subjects had filled in a questionnaire (n = 688). The aim of this cross-sectional study was to elucidate whether different individual and work factors are related to musculoskeletal symptoms in a specific body region. Due to the cross-sectional design, however, causality cannot be discussed. Univariate analyses and multiple logistic regression analyses were performed and yielded similar results. The latter analyses showed that in the present hospital setting, individual factors together with physical and psychosocial work factors were related to symptoms in the neck, low back, and hands; individual factors and psychosocial work factors were related to symptoms in the shoulders; while only individual factors were related to symptoms in the knees. The results of the present study showed that various individual factors and physical and psychosocial work factors were related to musculoskeletal symptoms in the different body regions. Thus, the identification of risk factors might have far-reaching implications for the way in which effective health programs for prevention should be designed in the hospital setting.

Risk indicators for reported over-exertion back injuries among female nursing personnel.

We conducted a case-referent study to identify and quantify work-related and non-work-related risk indicators for reported over-exertion back injuries among nursing personnel. The source population was all nursing personnel employed in the Stockholm County hospitals during a 32-month period. The 240 cases and 614 referents completed questionnaires about occupation, type of clinic, working hours, shift work, patient transfers, perceived exertion, back pain, prior back injury, job strain, body mass index (BMI), smoking, immigrant status, physical training, and self-rated fitness. The highest relative risks (RR) were observed for work-related factors: working at an orthopedic clinic (RR = 5.2; 95% CI = 2.7–10.2), ≥1 patient transfer/shift (RR = 2.7; 95% CI = 1.6–4.5), and working full-time (RR = 2.4; 95% CI = 1.6–3.6). Training in the use of transfer devices, and regular use of transfer devices, reduced the relative risk from patient transfer. Among the non-work-related factors, only body mass index ≥25 kg/m 2 and immigrant status was associated with a slight increase in relative risk.

Reproducibility of a Questionnaire for Assessment of Physical Load During Work and Leisure Time

A self-administered questionnaire on physical load in lifetime occupational work, in present job, and in present leisure activities was tested for reproducibility with the test-retest method in 126 male and 217 female workers from 30 occupations. The questionnaire contained 92 questions and nine different response scales. The results indicated that questions concerning physical activity retrospectively and in the present job, vibrations in the present job, working postures involving the whole body, and questions concerning specific leisure activities (eg ball games, skiing, etc) seem to offer sufficient reproducibility to be worth testing for validity, at least at a 5-point ordinal level. Questions concerning working postures involving parts of the body, including awkward postures, and questions concerning manual materials handling seem to offer too poor reproducibility to be used in studies in which the aim is to quantify duration in proportions of a typical working day and frequencies in times per hour. Questions concerning level of physical activity and exertion in domestic work seem to offer too poor reproducibility to be used at a 5-point ordinal level. Gender, age, and musculoskeletal complaints did not influence the reproducibility to any great extent.

d-Limonene exposure to humans by inhalation: uptake, distribution, elimination, and effects on the pulmonary function

The toxicokinetics of d-limonene were studied in human volunteers exposed by inhalation (2 h, work load 50 W) in an exposure chamber on three different occasions. The exposure concentrations were approximately 10, 225, and 450 mg/m3 d-limonene. The relative pulmonary uptake was high, approximately 70% of the amount supplied. The blood clearance of d-limonene observed in this study, 1.1 l kg-1 h-1, indicates that d-limonene is metabolized readily. About 1% of the total uptake was eliminated unchanged in the expired air after the end of exposure, while approximately 0.003% was eliminated in the urine. A long half-time in blood was observed in the slow elimination phase, which indicates accumulation in adipose tissues. A decrease in vital capacity was observed after exposure to d-limonene at a high exposure level. The subjects did not experience any irritative symptoms or symptoms related to the central nervous system (CNS).

Differences in the Association Between Psychosocial Work Conditions and Physical Work Load in Female- and Male-Dominated Occupations

This study investigated whether there is a relationship between high physical work load and adverse psychosocial work factors, and whether this relationship is different for women and men. Separate analyses for female registered nurses and assistant nurses were made because these are common occupations involving high physical and psychological demands. This study was part of the MUSIC-Norrtälje study, a population study with the overall aim of identifying risk factors for musculoskeletal disorders. The respondents, 1423 gainfully employed men and women, were randomly selected from the study population. The exposure assessments referred to a typical workday during the previous 12 months. Physical exposure was investigated by interview, psychosocial work factors by interview and questionnaire. For the women, but not the men, mainly routine work and a job strain situation, according to the model of Karasek and Theorell, increased the probability of having a high physical work load, assessed as a time-weighted average of energy expenditure in multiples of the resting metabolic rate. Results indicated that in female-dominated occupations, high physical work load might also imply adverse psychosocial conditions. A higher frequency of high physical work load and job strain was observed among assistant nurses compared with registered nurses. Covariance between physical and psychosocial demands makes it difficult to determine the relative influence of each in health problems. Results of the present study imply that this is a larger problem in studies of women than men.

Self-reported physical exertion in geriatric care : A risk indicator for low back symptoms ?

Study Design The study group consisted of 131 female nursing aides who took part in an intervention program with physical training or education. Assessments were performed before the intervention program and after 6 months. At follow‐up evaluation, 91 nursing aides remained in the study. Objectives To examine if perceived physical exertion was a risk indicator for low back symptoms, and to examine the relationship between perceived physical exertion, aerobic capacity, back endurance, psychological demands, and job control. Summary of Background Data Perceived physical exertion frequently is assessed in epidemiologic studies concerning low back symptoms. More information about the relationship between perceived exertion, other potential risk indicators, and symptoms may provide opportunities for effective prevention of symptoms. Methods Assessments were obtained by questionnaires and physical capacity tests. Results The nursing aides who reported high physical exertion and were 45 years of age or older were at greater risk in the follow‐up period for reporting new symptoms, continued symptoms with the same intensity, or more intense symptoms from the low back (rate ratio, 3.01; 95% confidence interval, 1.1‐8.2). The exposure variable correlated most strongly (r = 0.4) with perceived physical exertion was psychological demands. Conclusions The results indicated being aged 45 years or older, combined with high perceived physical exertion, was a risk indicator for low back symptoms. A relationship between perceived physical exertion and psychological demands was observed, but there was no influence of physical capacity on perceived physical exertion.

Validity of self-reported duration of work postures obtained by interview

Abstract The aim of the study was to validate interview data concerning the duration of four work postures (1) sitting, (2) standing/walking with hands above shoulder level, (3) standing/walking with hands between shoulder and knuckle level, and (4) standing/walking with hands below knuckle level. The self-reported time spent in each posture was tested in relation to observations and technical measurements in 20 subjects during two full working days. The linear relationships between self-reports and observations were strong for the three postures; sitting (r2=0.55), hands above shoulder level (r2=0.58) and hands below knuckle level (r2=0.69). Thus, using this interview technique, self-reports concerning time spent in (1) sitting, (2) standing/walking with hands above shoulder level and, (3) standing/walking with hands below knuckle level may be accurate enough for studying these work postures in epidemiological studies.

Can cardiovascular load in ergonomic epidemiology be estimated by self-report ?

In ergonomic epidemiology exposure to local loads as well as cardiovascular load may contribute to general and local fatigue and musculoskeletal disease. Self-reported exposure is often the only feasible method in large population studies. The aim of this study was to evaluate retrospectively self-reported physical activity and perceived exertion as estimates of cardiovascular load during occupational work. The study population consisted of 39 men, representing 25 different occupations, and 58 women, representing 28 occupations. Ratings of physical exertion (RPE scale) and physical activity (Edholm scale transferred to multiples of the basal metabolic rate, METs) at the end of a work shift were correlated with the average heart rate during the same work shift. In the male population, both RPE ratings and METs correlated significantly (P < .01) with the average heart rate. No such correlation was observed in the female population.

Influence of cigarette smoking on the toxicokinetics of toluene in humans

To study the influence of cigarette smoking on the toxicokinetics of toluene, 10 habitual smokers who intended to stop smoking were exposed to toluene vapor (3.2 mmol/m3, 4 h) at three different exposure occasions: (I) while the smoking habit was still ongoing, and (II and III) 1 and 3-4 wk, respectively, after the day at which the smoking habit was discontinued. Solvent concentrations in the exhaled air and in the blood as well as hippuric acid concentrations in the urine were measured during the exposure period and for 3 h after the exposure period. The apparent clearance of toluene decreased significantly (p less than 0.05) 3-4 wk after the smoking habit was discontinued. This decrease was not a consequence of the increased body weight noticed in the subjects. No statistically significant differences between the three exposure occasions in the elimination rate of hippuric acid could be demonstrated. Thus, cigarette smoking seems to enhance the elimination rate of toluene from the body, since the apparent clearance was decreased after smoking was stopped.

Life-time occupational exposure to heavy work and individual physical capacity

Abstract The aim of the present study was to retrospectively analyze the effect of occupational physical activity on maximal isometric hand grip strength and maximal oxygen consumption among males and females between 19 and 64 years of age in different occupations. A life-time occupational physical activity index was formed from questions in a questionnaire. The maximal isometric hand grip strength was measured with a dynamometer and maximal oxygen consumption was estimated from a submaximal bicycle ergometer test. The results showed a negative correlation between physical activity and estimated maximal oxygen consumption among males but no other statistically significant associations between life-time physical activity and the present physical capacity was found. The present results suggest that a high level of occupational physical activity does not maintain individual physical capacity.