小野 雄一郎

Objectives-To investigate the prevalence of neck, shoulder, and arm pain (NSAP) as well as low back pain (LBP) among hospital nurses, and to examine the association of work tasks and self estimated risk factors with NSAP and LBP. Methods-A cross sectional study was carried out in a national university hospital in Japan. Full time registered nurses in the wards (n=314) were selected for analysis. The questionnaire was composed of items on demographic conditions, severity of workloads in actual tasks, self estimated risk factors for fatigue, and musculoskeletal pain in the previous month. Rate ratios (RRs) and 95% confidence intervals (95% CIs) were calculated by the Cox's proportional hazards model to study the association of pain with variables related to work and demographic conditions. Results-The prevalences of low back, shoulder, neck, and arm pain in the previous month were 54.7%, 42.8%, 31.3%, and 18.6%, respectively. The prevalence of musculoskeletal symptoms among hospital nurses was higher than in previous studies. In the Cox's models for LBP and NSAP, there were no significant associations between musculoskeletal pain and the items related to work and demographic conditions. The RRs for LBP tended to be relatively higher for "accepting emergency patients" and some actual tasks. Some items of self estimated risk factors for fatigue tended to have relatively higher RRs for LBP and NSAP. Conclusions-It was suggested that musculoskeletal pain among hospital nurses may have associations with some actual tasks and items related to work postures, work control, and work organisation. Further studies, however, are necessary, as clear evidence of this potential association was not shown in the study.

An experimental study was performed to investigate a care-giver's lifting ability under various lifting conditions intransferring a patient from sitting to standing positions. Nine female volunteers of college students repeated lifting of a weight until they failed to lift a heavier weight. The load was set up to increase step by step for each trial, and lifting force and height were recorded during each trial with the use of Lido Lift(Lordan Biomedical Inc.). Three levels of height were chosen to cover different lifting positions of diverse body lengths of patients. Comparing loads which corresponded to the same lifting velocity under various lifting conditions, we assessed the effect of waist-belt and posture, i. e. stoop and squat, on the lifting ability of a care-giver. The results showed the advantage of the combination of the waist-belt and the squatting posture both at the level of load close to the lifting limit and at the level of reduced load. It was suggested that lifting ability of the subjects under various lifting condition scould be assessed at the reduced load level.

Comparisons were made of general and local physical work loads between two groups of 58 Japanese and 15 Swedish nursery school teachers. Heart rate, number of steps, rating of perceived exertion (RPE), frequency and time expended with respect to trunk. flexion, sitting/kneeling, and lifting/carrying loads of 1 kg or more were monitored during working hours. The average percentage heart rate increase in the maximal heart rate range was lower in the Japanese than in the Swedish teachers, However, all parameters of local physical work load indicating musculoskeletal stress were higher in the Japanese than in the Swedish teachers. The RPE was slightly higher in the Japanese than in the Swedish teachers. These features of general and local work load in the Japanese teachers were typically observed among the teachers in charge of very young children (0-2 years). The Japanese teachers in charge of children aged 3-5 years, on the other hand, had similar levels of both general and local work load as the Swedish teachers in charge of classes comprising children of various ages (1-5 years). The physical work load measured in the present study was not sufficient to explain the difference in the magnitude of musculoskeletal problems for nursery school teachers in the two countries, and other factors should now be examined.

Objectives - To investigate the prevalence and risk factors of epicondylitis among cooks in nursery schools in a cross sectional study because they are suspected to have strenuous workloads on the hands and arms. Methods - Prevalence of epicondylitis among 209 nursery school cooks and 366 control workers aged 40-59 were studied. Both groups consisted of women workers chosen from 1299 subjects who agreed to participate from 1329 social welfare employees in a city. All workers were interviewed with a questionnaire and had a clinical examination of the tenderness to palpation of epicondyles and epicondylar pain provoked by resisted extension and flexion of the wrist. Results - Nursery school cooks had a significantly higher prevalence of epicondylitis (11.5%) than the controls (2.5%). In a logistic regression model, job title of the cook was also found to have a strong association with epicondylitis (odds ratio (OR) 5.4, 95% confidence interval (95% CI) 2.4 to 11.9) after adjustment for age, body length, and body mass index. Weaker associations were also found between epicondylitis and suspected job stress or workload scores for mechanical workload and psychosocial stressors based on factor analysis. Conclusions - This study supported the hypothesis that nursery school cooks had a higher prevalence of epicondylitis than other workers with less strenuous hand and arm tasks. It was suggested that risk factors of epicondylitis would be multifactorial, including mechanical workload and psychosocial factors.

A cross-sectional questionnaire study was conducted on cooks working for nursery schools in N city in order to verify epidemiological evidence of the work-relatedness of low back pain among them. After female workers aged 30 or more were selected from a study base of 2,799 workers in social welfare facilities, low back pain prevalence of cooks (n=240) was compared with nursery school teachers (n=955). Age-standardized prevalence ratios (PRs) of low back pain were 1.9 (95% CI: 1.5-2.5) in cooks compared with nursery school teachers, Among cooks, relative risks of low back pain increased with the increase in the number of lunches to be prepared and decreased with the increase in the number of cooks making lunches in a logistic regression model controlling age and body length. Low back pain was also found to be associated with self-estimated job stressors/work load by logistic regression models. Multifactorial effects from ergonomic and psychosocial factors, and individual factors on the low back were suggested, From the viewpoint of epidemiological criteria for work-relatedness, it was concluded that the work-relatedness of low back pain among cooks in nursery schools was partially supported.

Objectives-To describe the nationwide occurrence of work related musculoskeletal injuries among all home care service workers in Sweden, and to identify relative risks and risk factors of the injuries. Methods-The study was based on work related injuries reported to the Swedish occupational injury information system in 1990-1. The work related musculoskeletal injuries were divided into overexertion accidents and musculoskeletal diseases. The incidence of the injuries in female home care service workers was compared with those in nursery school workers and all other employed women in Sweden. Results-In home care service workers, the annual incidence of injury from overexertion accidents and musculoskeletal diseases were 19.2 and 15.1 per 1000 workers, respectively, which was higher than those in nursery school workers and all employed women in Sweden. For five injury locations including the back, all the age standardised relative risks (SRR) of overexertion accidents exceeded 4.0, and most of those for musculoskeletal diseases were 1.5 or more in home care service workers compared with all other employed women in Sweden. Total duration of sick leave due to overexertion accidents was 7.7 times, and musculoskeletal diseases 3.5 times, longer than in nursery school workers. National loss due to sick leave resulting only musculoskeletal injuries in care service workers was about 8.2% of the total work related sick leave in all employed women in Sweden, although the number of home care service workers represented only some 5% of this population. Lifting other people was most frequently reported as the main risk cause of overexertion accidents in both kinds of workers. Conclusions-The results support the hypothesis that home care service workers have higher annual injury incidence of musculoskeletal injuries than nursery school workers due to physically stressful tasks that are far less common in nursery school workers.

Objective: Most prevalence studies of seasonal changes in mood and behavior have come from Western countries. The authors' goal was to determine the prevalence of seasonal changes in mood and behavior in a randomly selected group of Japanese workers. Method: They administered a Japanese translation of the Seasonal Pattern Assessment Questionnaire to 1,276 civil servants in Nagoya, Japan. Results: The estimated prevalence of winter seasonal affective disorder was 0.86%, the estimated Prevalence of winter subsyndromal seasonal affective disorder was 0.86%, the estimated prevalence of summer seasonal affective disorder was 0.94%, and the estimated prevalence of summer subsyndromal seasonal affective disorder was 2.12%. Conclusions: The authors conclude that seasonal changes in mood and behavior occur in Japan, but at a lower frequency and with a different profile than in the United States or Europe.

Relationship of Task Strain and Physical Strength to End-of-Work Fatigue among Nurses at Social Welfare Facilities: Midori Shimaoka, et al. Research Center of Health, Physical Fitness and Sports, Nagoya University-To study the relationship of task strain and physical fitness to fatigue among nurses employed at social welfare facilities, we investigated the degree of habitual end-of-work fatigue among 99 nurses (ages 20-49 years) in its relationship to both the degree of strain in various tasks and various indices of physical fitness. Results were as follows: (1) Fatigue complaint rates were nearly the same (35-38%) regardless of age. © 1988, The Japanese Pharmacological Society. All rights reserved. (2)Mean arm power and maximal oxygen uptake (Vo2max) were significantly lower in a high degree of fatigue group than a low degree of fatigue group. (3)Four of 21 tasks elicited strain complaint rates greater than 50%: “nursing of seriously ill patients”, “nursing of medical device-assisted patients”, “bathing care”, and “excretory/diaper changing care”. (4) Significant positive correlations were noted between the degree of fatigue and the degree of strain complaint with regard to “nursing of medical deviceassisted patients”, “bathing care”, and “excretory/diaper changing care”. (5) Strain complaint rates were significantly higher in a low arm power group than a high arm power group with regard to “nursing of seriously ill patients”, “nursing of medical deviceassisted patients”, and “excretory/diaper changing care”. (6) Strain complaint rates were significantly higher in a low Vo2max group than a high Vo2max group with regard to “nursing of medical device-assisted patients”, “bathing care”, and “excretory/diaper changing care”. These results suggest the need for measures to alleviate task strain and to increase arm strength and overall stamina so that nurs ing work does not result in excessive fatigue. © 1995, Japan Society for Occupational Health. All rights reserved.