Masaharu Kumashiro

Power Spectral Analysis of Heart Rate Variability in Healthy Young Women During the Normal Menstrual Cycle

This study investigated the fluctuations of autonomic nervous activities during the menstrual cycle.Twenty college females were tested for cardiovascular reactivity to mental challenge during both follicular and luteal phases across two menstrual cycles. Power spectral analysis of heart rate variability (HRV) was used to examine the autonomic nervous activities. At baseline, although heart rate and blood pressure did not differ across the menstrual cycle, the low-frequency (LF) component in the HRV was higher and the high-frequency (HF) component in the HRV was lower during the luteal phase than during the follicular phase. The LF/HF ratio was also significantly greater in the luteal phase. These data suggest that sympathetic nervous activities are predominant in the luteal phase as compared with follicular phase. In addition, the power spectral analysis of HRV has more sensitivity than heart rate or blood pressure in assessing the slight fluctuations of autonomic nervous activities during the menstrual cycle.

Aging and work

Changes of the Work Ability Index of Aging Workers related to the Participation in the Activities for Promoting Health and Work Ability: A 3-Year Program. Maintaining the Work Ability of Kitchen Workers. The Strict Agricultural Products Standard and the Difficulty of Agricultural Work for Aged Workers. A Study on the Usability of Mobile Phones for the Elderly. Health Status and Lifestyles of Elderly Japanese Workers. A Continuous Exercise Time and Psych-Physiological Reaction for a Suitable Prescriptive Exercise Program. The Effect of Aging on Lipid Metabolism and Aerobic Ability. The Study of the Work Accidents in the Fishery Industry. Renal Function Decline in Aged Workers Enhances Toxic Effect of Occupational Chemicals. Post-Polio Fatigue and Aging: A New Problem at Workplaces in Japan. Japanese Initiatives on Aging and Work: An Occupational Ergonomics Approach to Solving this Complex Problem. Occupational Gerontology: The Science Aimed at Older Employees. Promotion of Work Ability during Aging. Functional Fitness: Encouraging Human Struggle (Physical Activity) and Warning about the Cost of Technology. The Role of the Psychological Environment in Promoting the Health and Performance of Older Workers. Company Level Strategies for Promotion of Well-Being, Work Ability and Total Productivity. Developing a New Work System for Elderly Workers. Employment of the Elderly in Korea. The Theory and Practice of Work Re-Design in a Small and Medium-Sized Manufacturing Industry in an Aging Society. Occupational Activity and Aging. The Anthropometric Data of the Aging Workers in Taiwan. Survey of Prospects for Elderly Care Workers. Work Situation Evaluation as a Prerequisite for Productive Aging of Engineers and Innovators. Intergenerational Relations at Work in Sweden and the UK. A Work - Family Balance Approach to Research on Late Career. Work Climate and the Age-Hostile Workplace. Terminology of Aging used in Legislation and Government Policy. For Whom is a Disabled Pension a Good Solution when Musculoskeletal Disorders Prevent Work. The Management of Work-Related Stress with Regards to the Health of Older Workers. Characteristics and Perspectives of Occupational Accidents Involving Aged Workers in Korea. Development of a Work Support Tool for the Old with Work Postures as an Index. Measures for Healthy Aging: Lifestyle and Exercise. Age-conscious Personnel Policies and Productive Aging. Maintaining Work Ability of Elderly Workers. Support Systems for Elderly Workers. Part 6. Occupational Accidents and Incidents.

Power spectral analysis of heart rate variability in Type As and Type Bs during mental workload.

&NA; Recently several studies have suggested that there are differences in autonomic balance between Type As and Type Bs. This study evaluates a sympathovagal interaction in Type A (n = 8) and Type B (n = 11) male students during a mental arithmetic task by power spectral analysis of heart rate variability. The low‐frequency component to high‐frequency component ratio was significantly greater in Type As than in Type Bs during a resting period. No significant differences were found in heart rate changes and blood pressure between the two kinds of subject groups. The present findings indicate that there was a significant difference in sympathovagal balance between Type As and Bs. Type As showed dominant sympathetic activity.

Job Stress and Mental Health among Permanent Night Workers

Job Stress and Mental Health among Permanent Night Workers: Yoshihisa Fujino, et al. Department of Clinical Epidemiology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health—Shift work, including rotating shift night work, and permanent night work, causes mental health problems. In addition to the shift work system, job stress and individual background factors also relate to the mental health of workers, but details of job stress and mental health problems among permanent night workers are still unclear. The purpose of this study is to examine the amount of job stress and the mental health problems among permanent night workers, and also to examine what factors should determine the mental health condition of the permanent night worker. The study group consisted of 435 garbage workers, and 384 workers completed the questionnaire, which included the NIOSH generic job stress questionnaire and 30 items of the General Health Questionnaire (GHQ). Workers with a GHQ score of 7 or more were defined as having psychiatric disturbance. Multiple logistic regression was performed to estimate the odds ratios (ORs) for psychiatric disturbance, including age, type of work, working year, marital status, and some scales of the NIOSH generic job stress questionnaire. The married workers were less likely to have mental health problems than single workers (OR=0.49,95% 01=0.29‐0.85). The mental health of the workers with lower job control was better than the workers with higher job control (OR=0.46, 95% 01=0.26‐0.79). The workers with a higher workload were more likely to have mental health problems (OR=2.86, 95% CI=1.76‐4.67). This study showed that person with a high workload, high job control, and who were single had increased ORs for psychiatric disturbance among permanent night workers.

Fatigue sensation, electromyographical and hemodynamic changes of low back muscles during repeated static contraction

The effects of work strategy and a rest condition on the physiological changes of the erector spinae muscle were studied. Eleven volunteers repeated fatiguing static contractions of holding an industrial box in 30° trunk flexion for a repetition of 12 times interrupted by rests for which the duration was equal to the duration of each preceding contraction. Each contraction was stopped at two fatigue sensation levels; moderate or strong, which corresponded to Borg’s CR-10 3 and 5, as the work strategy conditions. The repeated contractions were performed for a total of eight conditions combined with the two rest conditions, with and without stretch exercise, and two contraction levels of 10 and 40% maximum pulling force in flexed posture (MVC) on separate days. Near-infrared spectroscopy and surface electromyography (EMG) were recorded. Amplitude and median frequency (MF) of EMG, oxy-hemoglobin, and deoxy-hemoglobin were calculated. MF related to fatigue sensation most closely. Oxy-hemoglobin decreased during each contraction. It, however, increased with repetition especially at 10% MVC and the increase was interpreted as adaptation to the work. The effect of the work strategy and the rest conditions was weak. MF decreased more in a strong work strategy condition than in a moderate one.

Ergonomics strategies and actions for achieving productive use of an ageing work-force

In this report, a basic ERGOMA (Ergonomics in Industrial Management) strategy is proposed as a policy for corporate production and employment in countries where ageing populations and reduced birth rates are imminent, and a strategy related to this is proposed. Specifically, as a strategy at the company level, the results of survey studies aimed at the development of methods for determining job capacity, to enable effective use of the labour of ageing workers, were summarized. A number of the insights gained here are steps in the development of a foundational methodology for practical use, and in actual practice a number of these insights must be subjected to measurements. However, the theory and newly developed methodology described here are thought to represent significant changes from the approaches to job capacity diagnosis and assessment published in the past and from the stance towards utilization of an ageing work-force. The author is confident that this represents new progress in one of the ergonomics approach to dealing with the working environment of ageing workers and an ageing work-force in general.

The relationship between work ability and oxidative stress in Japanese workers

Work ability is based on the balance between personal resources and work demand. This study focused on the personal resources component of work ability. The aims of this study were to elucidate the association between work ability and cardiovascular (CV) risk factors, particularly oxidative stress, and to estimate the effect of a community-implemented lifestyle modification programme on work ability and CV risk factors. Urinary 8-iso-prostaglandin F2α (PGF2α), a biomarker of oxidative stress, was negatively correlated with psychological resources, as measured by the Work Ability Index (WAI). Overall WAI score was unchanged following the programme, while CV risk factors and antioxidative activity improved. A reduction in PGF2α levels was correlated with an improvement in subjective work ability relative to job demands, as assessed by a WAI item. Taken together, the results suggest that lifestyle modification programmes enhance the personal resources component of work ability and are associated with a reduction in oxidative stress. Practitioner Summary: We demonstrated the capacity of a lifestyle modification programme to augment personal resources by reducing CV risk factors such as oxidative stress. In addition, since the community-implemented lifestyle modification programme minimally affected work ability, ‘worksite’ health promotion programmes might more effectively enhance personal resources.

Sense of coherence modifies the effect of overtime work on mental health

Sense of coherence modifies the effect of overtime work on mental health: Masanori Ohta, et al. Department of Health Development, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan

Visual Recognition Memory Test Performance was Improved in Older Adults by Extending Encoding Time and Repeating Test Trials

Visual Recognition Memory Test Performance was Improved in Older Adults by Extending Encoding Time and Repeating Test Trials: Chalermsiri THEPPITAK, et al. Department of Ergonomics, University of Occupational and Environmental Health, Japan—

Work Load in Culture of Shiitake Mushroom

Plugging-in of a wood piece for the culture of shiitake mushroom is one of machine-assisted works in forestry, and is achieved by the use of an electric drill. The purpose of this study is to evaluate the effects of this work on the psychophysiological functions of workers. The work consisted of two conditions ; working on a work table and working on the bare ground. The work load was examined by multifaceted observation. Results indicated that the CFF and the function of concentration (TAF-test) when compared with pre-work values were not significantly reduced after approximately 50 minutes of work. But the work perfonuance produced a local muscular load due to work in unnatural work postures and the workers feel fatigue due to work itself. However, working on the work table had effects on mitigation on the work load, shortening of the working time and improvement of the work postures.