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Biomedical subjects

G Wickström

Publications and source records attributed to G Wickström.

At least 19 recordsLinked to original sources
PubMed2000

The "Hawthorne effect"--what did the original Hawthorne studies actually show?

The "Hawthorne effect" is often mentioned as a possible explanation for positive results in intervention studies. It is used to cover many phenomena, not only unwitting confounding of variables under study by the study itself, but also behavioral change due to an awareness of being observed, active compliance with the supposed wishes of researchers because of special attention received, or positive response to the stimulus being introduced. At times, the term seems to be used as a social equivalent to "placebo effect". In social research, there is much critical literature indicating that, in general, the term "Hawthorne effect" should be avoided. Instead of referring to the ambiguous and disputable Hawthorne effect when evaluating intervention effectiveness, researchers should introduce specific psychological and social variables that may have affected the outcome under study but were not monitored during the project, along with the possible effect on the observed results.

Effect Modifier, Epidemiologic↗
PubMed1996

A video-based method for evaluation of low-back load in long-cycle jobs.

A method for evaluation of the physical load on the lumbar spine in industrial work is presented. It is suitable for identification of high spinal loads and their time duration. The method is based on biomechanical analysis of video-recordings. It takes into account the posture of the body as such, as well as the possible occurrence of external load and support. Compression of the L5-S1 intervertebral disc and strain on the lumbodorsal fascia is determined at 5-s intervals in each work task.

Biomechanical Phenomena↗
PubMed1991

Tenderness and pain in neck and shoulders in relation to Type A behaviour.

158 males employees in the metal industry, aged 35-44 years, were examined to determine the prevalence of tenderness and pain in the neck and shoulders. Type A behaviour was assessed by a series of 16 questions. One or more tender sites were found in 30% and more than three in 7% of the examined employees. Tenderness was twice as common among those with interview-based pain in the past 12 months (40%) as among those without pain (23%). Those with tenderness on palpation more often had a type A behaviour than those without tenderness (p = 0.010). The association was modified by pain but not by occupation. One explanation for the association between tenderness and behaviour might be that type A personality is associated with increased muscle activity in the neck and shoulders leading to muscular fatigue and tenderness.

Adult↗
PubMed1991

Reproducibility of nine tests to measure spinal mobility and trunk muscle strength.

The reproducibility of nine back function tests suitable for use in the occupational health service was determined in 30 male employees. The correlation of three tests made with a tape measure--forward bending, modified Schober, and side bending--was high in both intra- and inter-observer comparisons (r = 0.82-0.96). Immediate repetition of the testing procedure improved the performance in the forward and side bending tests. The reproducibility was also good for the tests of dynamic (K = 0.57-0.78) and endurance (r = 0.90-0.96) strength of the abdominal muscles and quite good for the test of endurance strength of the back muscles (r = 0.74-0.80). The differences between the examiners must be taken into account in the modified Schober test, and in testing the flexibility of the hip flexors and hamstrings and the endurance strength of the back muscles.

Adult↗
PubMed1990

Radiographically detectable degenerative changes of the lumbar spine among concrete reinforcement workers and house painters.

In this study of lumbar degeneration and the role of mechanical loading in its development, lateral lumbar radiographs of 216 concrete reinforcement workers and 201 house painters aged 25-54 years were examined. Disc space narrowing occurred at about 10 years and spondylophytes at about 5 years younger age in the former than in the latter group. Risk ratios (RR) were estimated from the regression coefficients of logistic regression models. RR for the univariate effect of occupation on disc space narrowing was 1.8, and adjustment for age, earlier back accidents, height, body mass index and smoking had only a minor effect on this relationship, adjusted RR 1.8. The crude RR for spondylophytes was 1.5, and the adjusted RR 1.6. Earlier back accidents showed a significant univariate relationship with DSN, but in multivariate analysis this variate did not retain its significance. It was concluded that heavy physical work enhances the degenerative process of the lumbar spine. Materials handling and postural loading are proposed to be occupational factors of importance in the development of both disc space narrowing and spondylophytes.

Adult↗
PubMed1989

Predictors of sciatic pain among concrete reinforcement workers and house painters--a five-year follow-up.

In a study of the association of occupation and several other determinants with the occurrence of sciatic pain, 167 concrete reinforcement workers and 161 house painters were followed for five years. Base-line data were obtained with a questionnaire, an interview on back symptoms, a clinical examination, and a radiograph of the lumbar spine. Follow-up data on back symptoms were obtained with a postal questionnaire. Concrete reinforcement work was associated with an increase in the risk of sciatic pain, in both a cross-sectional and a prospective study. Reported back accidents contributed to the risk of sciatic pain. Previous history of back symptoms was the most powerful predictor of sciatic pain prospectively. Degenerative changes were related to sciatic pain in retrospect, but prospectively this relationship was weaker. Body height and history of stress episodes showed some association with sciatic pain; abdominal muscle strength, body mass index, and smoking did not; and back muscle strength was associated only retrospectively.

Adult↗
PubMed1989

Radiographically detectable lumbar degenerative changes as risk indicators of back pain. A cross-sectional epidemiologic study of concrete reinforcement workers and house painters.

The association between radiographically detectable degenerative changes in the lumbar spine and back symptoms was studied, along with the possible effect of occupational work load. The subjects were 216 concrete reinforcement workers and 201 house painters. A questionnaire provided information on work history and earlier back accidents, and a standardized interview produced data on back symptoms. The occurrence of disc space narrowing, anterior and posterior spondylophytes, and end-plate sclerosis was recorded separately for each intervertebral space from lateral lumbar radiographs. Moderate to severe degenerative changes were associated with increased risk of sciatic pain but not with the occurrence of lumbago or nonspecific back pain. The different types of degenerative changes provided no further information. In a multivariate logistic regression analysis degenerative changes and earlier back accidents were significant independent predictors of sciatic pain. When these two variates were allowed for, the effect of occupation was not significant.

Adult↗
PubMed1987

Determination of sciatica in epidemiologic research.

The international classification of diseases is unsuitable for epidemiologic research on the etiology of degenerative back disease. In cross-sectional studies of occupationally active populations, the occurrence of various symptoms and signs of back disease may be established. However, recommendations as to what data to gather or how to combine it into meaningful entireties are not yet established. To validate reported sciatic pain by clinical findings, 252 reinforcement workers and 231 painters, all men, 20-64 years of age, were examined by nine tests. In the reinforcement workers exposed to heavy occupational loads the reports of sciatica during the previous month were clearly related to several clinical findings. The tests for restriction and pain on bending forward and sideward gave sensitivity values of 0.36-0.61 and specificity values of 0.82-0.87. Combining the results of the separate tests into pairs enhanced the sensitivity to 0.62-0.68, but reduced the specificity to 0.77-0.78. Referring to the current results, recommendations include a structured inquiry into sciatic pain during the previous month, backed up by clinical tests for range of and pain on lumbar movement, when studying the occurrence of back syndromes in physically heavy trades.

Adult↗
PubMed1987

A study of sleep patterns on two Finnish icebreakers, ambulatory recording and automatic analysis.

The effects of noise and vibration on sleep in Finnish ice-breaking ships were studied in healthy volunteer workers and a control group. EEG, EOG and EMG were recorded by means of portable tape recorders. The recordings were analysed by an automatic hybrid system. Both sleep stage parameters and the quantities of single EEG waveforms were used for the evaluation of the sleep quality. Measurements were made before, during and after the ice-breaking season in the winter. Higher amounts of wakefulness and sleep stage 1, and lower amounts of delta and theta activity were found on a night during the ice-breaking season, compared with a night after the season. This was interpreted as indicating a "lightening" of sleep, caused by noise and vibration. No differences between the nights before and during the ice-breaking season were observed. The crew members had an appr. 1 h shorter Time In Bed and Sleep Period Time than the controls also on the nights studied ashore. Because of the small number of subjects the results are not conclusive, even though statistically significant differences were obtained. The delta activity in seconds/minute seems to be a more informative measure than the percentages of the sleep stages S3 and S4. The possibility of using the theta activity as a measure of the length of sleep should be further investigated.

Adult↗
PubMed1985

Suicides among male Finnish seafarers.

On analysing death registers of Finnish seafarers, 117 cases of suicide were found among active professional males in the years 1965-77. The suicide rate of the officers was similar to that of occupationally active males in the general population, while the suicide rate of the crew was 2 1/2 times higher (P less than 0.05). Many of the men who committed suicide had been at sea 5 to 10 years. Before their death they frequently changed ships.

Adolescent↗
PubMed1985

Strain on the back in concrete reinforcement work.

To investigate the long term effect of heavy construction work on the back the occurrence of postures, lifting, carrying, and accidents in concrete reinforcement work and in maintenance house painting were measured. The 32 620 observations covering 272 work hours showed that reinforcement work necessitated stooped postures and heavy lifting more often than did painting. Reported minor back accidents were more than ten times as common in reinforcement work than in painting (1.3 compared with 0.11 accidents per man-year, p less than 0.001). Accidents of the musculoskeletal system, registered by the insurance companies, were also several times more common in reinforcement work (81 compared with 25 per 1000 man-years, p less than 0.001). The premature development of lumbar degeneration detected in the clinical study of the reinforcement workers was evidently due to the occupational strain on the back. The different types of hazardous back loads probably potentiate the effects of each other.

Accidents, Occupational↗
PubMed1985

Occupational dermatoses in the food industry.

The occurrence of skin diseases in employees engaged in the food industry has been investigated by means of an epidemiological cross-sectional study. Of the 1052 workers in a large factory in Turku (Finland), 17% reported a current skin disease. Occupational eczema was diagnosed in 8,5% of the 541 female employees examined in detail. It was twice as common among those handling fish, meat and vegetables or making "instant" food as among those making confectionery. Hand eczema was present in 15% of the 196 workers handling food, in 8,5% of the 259 confectioners and in 6% of the 86 office employees. History of atopic dermatitis could be revealed in 30% and history of asthma or hay fever without dermatitis in 15% of the employees with current hand eczema.

Adolescent↗
PubMed1984

Uncoupler-accelerated efflux of 5-hydroxytryptamine from platelets of healthy subjects and patients with unipolar and bipolar depression.

The efflux of 14C-5-hydroxytryptamine (5HT) from platelets of 25 depressed patients (16 unipolar and 9 bipolar) and 22 control subjects was studied in the presence of carbamyl cyanide m-chlorophenylhydrazone (FCCP), which dissipates H+ gradients. FCCP (0.31 microM), at 10 minutes' incubation time, enhanced the efflux of 14C-5HT to a significantly higher extent from platelets of patients with bipolar depression than from platelets of control subjects. An analysis of variance revealed a significant interaction between the diagnostic categories (unipolar, bipolar, and control) and sex in accounting for variation of the FCCP-evoked efflux. The diagnostic category X sex effect was also significant. The results reported indicate that the FCCP-evoked efflux of 5HT is an easily measured biochemical parameter of possible diagnostic interest.

Adult↗
PubMed1984

Solvent exposure in construction and maintenance painting.

Exposure to solvents in interior house painting was determined by industrial hygiene surveys and questionnaires on work history. Painting work was observed in 92 work situations at 18 sites, mainly during maintenance work. The effects of the size of the work area, the volume of air, the type of paint, the amount used, the method of application, and the use of ventilation on the solvent concentrations were also studied. In small, poorly ventilated rooms the concentration of solvent naphtha averaged 275 ppm when alkyd paints were used. Wall and ceiling painting with alkyd paints yielded an average solvent naphtha concentration of 210 ppm, and window and door painting 80 ppm. The presence of a strong draft reduced the solvent concentrations by two-thirds. The painters' average lifetime dose of solvent naphtha was 12.2 kg, the average annual dose 0.54 kg. These levels decreased over the study period. The mean 8-h concentration of solvent naphtha in the breathing zone averaged 40 ppm over the painters' total worklife.

Air Pollutants, Occupational↗
PubMed1983

Psychological function changes among maintenance house painters exposed to low levels of organic solvent mixtures.

The adverse psychological effects of long-term exposure to organic solvent mixtures were studied among 219 maintenance house painters. Their mean age was 42 years and the duration of exposure 22 years. 229 reinforcement workers of the same mean age served as a nonexposed reference group. The groups were also matched according to pre-exposure intellectual level. The painters average exposure to white spirit was estimated to be 40 ppm. The maintenance house painters were characterized by defects in short-term visual memory and prolonged simple reaction times. Some slight relationships were found between low test performances and various individual indices of long-term exposure to solvents. The results implied that adverse psychological effects existed even though the exposure level was much lower than the hygienic standard applied for white spirit in many countries.

Adult↗
PubMed1983

Knee degeneration in concrete reinforcement workers.

The loads on the knees in concrete reinforcement work and maintenance painting were analysed on eight construction work sites. A total of 352 reinforcement workers and 231 painters. Finnish men aged 20-64, were clinically and radiologically examined to determine the condition of the knee joints in active workers. The loads on the knees and the occurrence of minor injuries and accidents were higher in reinforcement work than in painting, but the occurrence of symptoms, clinical signs, and radiological findings was equally common in both groups. Reinforcement work seemed to provoke more symptoms from degenerated knees than painting.

Adult↗