Take-off aerodynamics in ski jumping.

The effect of aerodynamic forces on the force-time characteristics of the simulated ski jumping take-off was examined in a wind tunnel. Vertical and horizontal ground reaction forces were recorded with a force plate installed under the wind tunnel floor. The jumpers performed take-offs in non-wind conditions and in various wind conditions (21-33 m s(-1)). EMGs of the important take-off muscles were recorded from one jumper. The dramatic decrease in take-off time found in all jumpers can be considered as the result of the influence of aerodynamic lift. The loss in impulse due to the shorter force production time with the same take-off force is compensated with the increase in lift force, resulting in a higher vertical velocity (V(v)) than is expected from the conventional calculation of V(v) from the force impulse. The wind conditions emphasized the explosiveness of the ski jumping take-off. The aerodynamic lift and drag forces which characterize the aerodynamic quality of the initial take-off position (static in-run position) varied widely even between the examined elite ski jumpers. According to the computer simulation these differences can decisively affect jumping distance. The proper utilization of the prevailing aerodynamic forces before and during take-off is a very important prerequisite for achieving a good flight position.

Radiographic abnormalities among Finnish construction, shipyard and asbestos industry workers.

OBJECTIVES: The prevalence of asbestos-related radiographic abnormalities was surveyed among Finnish construction, shipyard, and asbestos industry workers. METHODS: The radiographic screening focused on active and retired workers who were under the age of 70 years and had been employed for at least 10 years in construction or for at least 1 year in shipyards or in the asbestos industry. In 1990-1992, 18,943 people participated in an X-ray examination of the lungs and an interview on work history and exposure. The criteria for a positive radiological finding were (i) small irregular lung opacities clearly consistent with interstitial pulmonary fibrosis (ILO 1/1 or higher), (ii) lung opacities indicating mild pulmonary fibrosis (ILO 1/0) with unilateral or bilateral pleural plaques, (iii) marked adhesions with or without thickening of the visceral pleura, or (iv) findings consistent with bilateral pleural plaques. RESULTS: Fulfilling the criteria were 4133 workers (22%) (22% from construction, 16% from shipyards, and 24% from the asbestos industry). The radiological findings included signs of pulmonary fibrosis (3%), changes in the visceral pleura (7%), bilateral plaques (17%), and unilateral plaques (10%). Occupational disease was diagnosed according to the Finnish insurance regulations for three-fourths of those referred for further examinations, 96% being abnormalities in the pleura and 4% being asbestosis. CONCLUSIONS: Exposure to asbestos dust has been common in ordinary construction work, and, consequently, radiographic abnormalities (mostly pleural) occur frequently among active and retired construction workers.

[Diabetic nephropathy--screening, follow-up and treatment. Nephropathy Study Groups of The Finnish Diabetes Organization]. / Diabetesnefropati--screening, uppföljning och behandling. Nefropatiarbetsgruppen vid Finlands Diabetesförbund]

Owing to advances in the diagnosis and treatment of diabetic nephropathy, its management has become more active and is now initiated earlier after the presence of microalbuminuria has been established. In 1996 the Finnish Diabetic Association's nephropathy group issued recommendations concerning screening for diabetic nephropathy, and treatment and follow-up of patients with the disease.

Screening for asbestos-induced diseases in Finland.

Screening for asbestos-induced diseases in Finland was carried out in 1990-1992 as a part of the Asbestos Program of the Finnish Institute of Occupational Health. The aim of the present study was to find the workers who had developed an asbestos-induced disease in certain occupations. Examination of active or retired workers included a personal interview on work history and asbestos exposure, and a chest X-ray. The target group for the screening comprised workers under 70 years of age who had worked at least for 10 years in construction, 1 year in a shipyard or in the manufacture of asbestos products. A preliminary questionnaire was sent to 54,409 workers, 18,943 of whom finally participated in the screening examination. The mean age of the workers was 53 years; 95% were employed in construction, 2% in shipyards, and 3% in the asbestos industry. The criteria for a positive screening result were (1) a radiographic finding clearly indicating lung fibrosis (at least ILO category 1/1), (2) a radiographic finding indicating mild lung fibrosis (ILO category 1/0) with unilateral or bilateral pleural plaques, (3) marked abnormalities of the visceral pleura (marked adhesions with or without pleural thickening), or (4) bilateral pleural plaques. The positive cases totalled 4,133 (22%) and were sent for further investigation. In addition to the screening, information on the presence of asbestos in the work environment, prevention of asbestos exposure, as well as on the health effects of asbestos exposure and smoking were given to the participating workers. The screening acted as a preliminary survey to prompt further national follow-up of asbestos-induced diseases among the workers who have been exposed to asbestos. This article presents the material, methods, and overall results of the screening.

Seven-year follow-up of white-finger symptoms and radiographic wrist findings in lumberjacks and referents.

OBJECTIVES: In 1978, a cross-sectional study of 279 lumberjacks exposed to hand-arm vibration and 178 unexposed referents was conducted. The aim of the present study was to provide a seven-year follow-up on (i) the changes in the white-finger symptoms among the lumberjacks and the referents, (ii) the effect of white-finger symptoms on the professional prognosis of the lumberjacks, and (iii) the relationship between hand-arm vibration and changes in wrist bones. METHODS: The methods consisted of a questionnaire, a routine clinical examination, and radiographs of the wrists and hands. The examinations were conducted as a field study using a mobile unit. RESULTS: The prevalence of white-finger symptoms was 18% among the lumberjacks and 3% among the referents in the original study. Seven years later 213 lumberjacks and 140 referents participated in the follow-up. The prevalence of white-finger symptoms was 24.9 among the lumberjacks and 5.7 among the referents, and the seven-year cumulative incidence was 14.7% among the lumberjacks and 2.3% among the referents. After allowance for age, there was no difference in the incidence of white-finger symptoms between the lumberjacks with fewer than 15 years of exposure and the referents, but the risk increased with increasing duration of exposure (risk ratio 8.9, 95% confidence interval 2.5-28.9 for those exposed at least 25 years). There was no difference between the two groups in the prevalence of radiographically detectable translucencies or osteoarthrotic changes in the wrists and hands. CONCLUSION: According to the results, white-finger symptoms are still a problem among lumberjacks who started chain-saw work before 1970.

Effects of work-oriented fitness courses in lumberjacks with low back pain.

This prospective controlled study examined changes in fitness, health, and work ability after a work-oriented physical fitness course arranged for lumberjacks experiencing low back pain but being still at work. The 1-week courses were designed to activate exercising during leisure time and consisted of fitness tests, various types of exercise, and lectures. Eighty-seven lumberjacks participated in the courses and 61 subjects served as controls. Questionnaire data obtained before and 1 year after the course were available for 78 (90%) of the course participants and 41 (67%) of the controls. In the intervention group, perceived fitness, health, and work ability improved and ergonomic strain at work decreased. Both groups reported an increased frequency of leisure-time physical activity. There were between- group differences in the development of fitness, health, distress symptoms, and subjective work ability, whereas the changes in physical activity, back and musculoskeletal symptoms, or ergonomic strain did not differ between the groups. In a 6-month follow up, muscle function improved in the intervention group, but no change was observed in aerobic capacity. There was a tendency of the number of back pain-related sickness leaves, but not of their duration, to develop more favorably in the intervention group, when data from the year before and the year after the course were compared.

Histamine control affects the weal produced by the adjacent diluent control in skin prick tests.

The effect of histamine chloride control (10 mg/ml) on the weal reaction produced by the adjacent test solution (buffered glycerol-saline diluent control) in skin prick tests was studied among 270 peat workers and 214 lumberjacks. The diluent control was placed on the skin at two test sites: 3-4 cm and 18-19 cm from the site of the histamine control. Prick-test lancets (Dome/Hollister-Stier) were used to prick the skin. Weal areas of 6 mm2 or larger were considered to be positive reactions. In both populations the diluent control caused positive reactions nearly three times more often when the test site was 3-4 cm from the site of the histamine control than when it was 18-19 cm away from the control (P less than 0.001). Similar relationships might be found between histamine control and allergen solutions. This finding should be taken into account in histamine-based standardisation of the results of skin prick tests as well as in biological standardization of allergen solutions.

Prevalence of depressive symptoms and depression in elderly Finnish home nursing patients and home help clients.

Depressive symptoms in a population (N = 419) aged 65 years or over and receiving home nursing, home help or both were assessed by postal questionnaires including the Zung self-rating depression scale (SDS). Eighty-six percent participated, and 38 percent of both men and women scored 45 raw sumpoints or more in the SDS. The mean of the raw sumpoints was 42.1 (+/- 9.6) for men (N = 100) and 41.4 (+/- 9.0) for women (N = 238, the difference being nonsignificant. Home help clients scored less than home nursing patients or patients receiving both home nursing and home help. The population scoring 45 raw SDS sumpoints or more was investigated by a general practitioner, and the diagnosis of depression was made according to DSM III-criteria. The clinical investigations showed 26 percent of both men and women who participated to be depressive. Chronic depression was the most common class, followed by atypical depression. About two thirds of the depressive men and half of the depressive women were 'new' cases in that it had not been realized earlier that they suffer from depression. Atypical depression was the class where underdiagnozing was most evident. Among elderly men psychomotor retardation, libido loss, anorexia and indecisiveness and among elderly women psychomotor retardation, indecisiveness, emptiness and diurnal variation were common symptoms of depression.